diff options
Diffstat (limited to 'Documentation/arm')
68 files changed, 3917 insertions, 647 deletions
diff --git a/Documentation/arm/00-INDEX b/Documentation/arm/00-INDEX index 82e418d648d..3b08bc2b04c 100644 --- a/Documentation/arm/00-INDEX +++ b/Documentation/arm/00-INDEX @@ -4,8 +4,10 @@ Booting - requirements for booting Interrupts - ARM Interrupt subsystem documentation -IXP2000 - - Release Notes for Linux on Intel's IXP2000 Network Processor +IXP4xx + - Intel IXP4xx Network processor. +msm + - MSM specific documentation Netwinder - Netwinder specific documentation Porting @@ -20,13 +22,31 @@ Samsung-S3C24XX - S3C24XX ARM Linux Overview Sharp-LH - Linux on Sharp LH79524 and LH7A40X System On a Chip (SOC) +SPEAr + - ST SPEAr platform Linux Overview VFP/ - Release notes for Linux Kernel Vector Floating Point support code +cluster-pm-race-avoidance.txt + - Algorithm for CPU and Cluster setup/teardown empeg/ - Ltd's Empeg MP3 Car Audio Player +firmware.txt + - Secure firmware registration and calling. +kernel_mode_neon.txt + - How to use NEON instructions in kernel mode +kernel_user_helpers.txt + - Helper functions in kernel space made available for userspace. mem_alignment - alignment abort handler documentation memory.txt - description of the virtual memory layout nwfpe/ - NWFPE floating point emulator documentation +swp_emulation + - SWP/SWPB emulation handler/logging description +tcm.txt + - ARM Tightly Coupled Memory +uefi.txt + - [U]EFI configuration and runtime services documentation +vlocks.txt + - Voting locks, low-level mechanism relying on memory system atomic writes. diff --git a/Documentation/arm/Booting b/Documentation/arm/Booting index 76850295af8..371814a3671 100644 --- a/Documentation/arm/Booting +++ b/Documentation/arm/Booting @@ -18,7 +18,8 @@ following: 2. Initialise one serial port. 3. Detect the machine type. 4. Setup the kernel tagged list. -5. Call the kernel image. +5. Load initramfs. +6. Call the kernel image. 1. Setup and initialise RAM @@ -65,13 +66,19 @@ looks at the connected hardware is beyond the scope of this document. The boot loader must ultimately be able to provide a MACH_TYPE_xxx value to the kernel. (see linux/arch/arm/tools/mach-types). - -4. Setup the kernel tagged list -------------------------------- +4. Setup boot data +------------------ Existing boot loaders: OPTIONAL, HIGHLY RECOMMENDED New boot loaders: MANDATORY +The boot loader must provide either a tagged list or a dtb image for +passing configuration data to the kernel. The physical address of the +boot data is passed to the kernel in register r2. + +4a. Setup the kernel tagged list +-------------------------------- + The boot loader must create and initialise the kernel tagged list. A valid tagged list starts with ATAG_CORE and ends with ATAG_NONE. The ATAG_CORE tag may or may not be empty. An empty ATAG_CORE tag @@ -101,7 +108,40 @@ The tagged list must be placed in a region of memory where neither the kernel decompressor nor initrd 'bootp' program will overwrite it. The recommended placement is in the first 16KiB of RAM. -5. Calling the kernel image +4b. Setup the device tree +------------------------- + +The boot loader must load a device tree image (dtb) into system ram +at a 64bit aligned address and initialize it with the boot data. The +dtb format is documented in Documentation/devicetree/booting-without-of.txt. +The kernel will look for the dtb magic value of 0xd00dfeed at the dtb +physical address to determine if a dtb has been passed instead of a +tagged list. + +The boot loader must pass at a minimum the size and location of the +system memory, and the root filesystem location. The dtb must be +placed in a region of memory where the kernel decompressor will not +overwrite it, whilst remaining within the region which will be covered +by the kernel's low-memory mapping. + +A safe location is just above the 128MiB boundary from start of RAM. + +5. Load initramfs. +------------------ + +Existing boot loaders: OPTIONAL +New boot loaders: OPTIONAL + +If an initramfs is in use then, as with the dtb, it must be placed in +a region of memory where the kernel decompressor will not overwrite it +while also with the region which will be covered by the kernel's +low-memory mapping. + +A safe location is just above the device tree blob which itself will +be loaded just above the 128MiB boundary from the start of RAM as +recommended above. + +6. Calling the kernel image --------------------------- Existing boot loaders: MANDATORY @@ -112,11 +152,17 @@ is stored in flash, and is linked correctly to be run from flash, then it is legal for the boot loader to call the zImage in flash directly. -The zImage may also be placed in system RAM (at any location) and -called there. Note that the kernel uses 16K of RAM below the image -to store page tables. The recommended placement is 32KiB into RAM. +The zImage may also be placed in system RAM and called there. The +kernel should be placed in the first 128MiB of RAM. It is recommended +that it is loaded above 32MiB in order to avoid the need to relocate +prior to decompression, which will make the boot process slightly +faster. -In either case, the following conditions must be met: +When booting a raw (non-zImage) kernel the constraints are tighter. +In this case the kernel must be loaded at an offset into system equal +to TEXT_OFFSET - PAGE_OFFSET. + +In any case, the following conditions must be met: - Quiesce all DMA capable devices so that memory does not get corrupted by bogus network packets or disk data. This will save @@ -125,17 +171,43 @@ In either case, the following conditions must be met: - CPU register settings r0 = 0, r1 = machine type number discovered in (3) above. - r2 = physical address of tagged list in system RAM. + r2 = physical address of tagged list in system RAM, or + physical address of device tree block (dtb) in system RAM - CPU mode All forms of interrupts must be disabled (IRQs and FIQs) - The CPU must be in SVC mode. (A special exception exists for Angel) + + For CPUs which do not include the ARM virtualization extensions, the + CPU must be in SVC mode. (A special exception exists for Angel) + + CPUs which include support for the virtualization extensions can be + entered in HYP mode in order to enable the kernel to make full use of + these extensions. This is the recommended boot method for such CPUs, + unless the virtualisations are already in use by a pre-installed + hypervisor. + + If the kernel is not entered in HYP mode for any reason, it must be + entered in SVC mode. - Caches, MMUs The MMU must be off. Instruction cache may be on or off. Data cache must be off. + If the kernel is entered in HYP mode, the above requirements apply to + the HYP mode configuration in addition to the ordinary PL1 (privileged + kernel modes) configuration. In addition, all traps into the + hypervisor must be disabled, and PL1 access must be granted for all + peripherals and CPU resources for which this is architecturally + possible. Except for entering in HYP mode, the system configuration + should be such that a kernel which does not include support for the + virtualization extensions can boot correctly without extra help. + - The boot loader is expected to call the kernel image by jumping directly to the first instruction of the kernel image. + On CPUs supporting the ARM instruction set, the entry must be + made in ARM state, even for a Thumb-2 kernel. + + On CPUs supporting only the Thumb instruction set such as + Cortex-M class CPUs, the entry must be made in Thumb state. diff --git a/Documentation/arm/IXP2000 b/Documentation/arm/IXP2000 deleted file mode 100644 index e0148b6b2c4..00000000000 --- a/Documentation/arm/IXP2000 +++ /dev/null @@ -1,69 +0,0 @@ - -------------------------------------------------------------------------- -Release Notes for Linux on Intel's IXP2000 Network Processor - -Maintained by Deepak Saxena <dsaxena@plexity.net> -------------------------------------------------------------------------- - -1. Overview - -Intel's IXP2000 family of NPUs (IXP2400, IXP2800, IXP2850) is designed -for high-performance network applications such high-availability -telecom systems. In addition to an XScale core, it contains up to 8 -"MicroEngines" that run special code, several high-end networking -interfaces (UTOPIA, SPI, etc), a PCI host bridge, one serial port, -flash interface, and some other odds and ends. For more information, see: - -http://developer.intel.com/design/network/products/npfamily/ixp2xxx.htm - -2. Linux Support - -Linux currently supports the following features on the IXP2000 NPUs: - -- On-chip serial -- PCI -- Flash (MTD/JFFS2) -- I2C through GPIO -- Timers (watchdog, OS) - -That is about all we can support under Linux ATM b/c the core networking -components of the chip are accessed via Intel's closed source SDK. -Please contact Intel directly on issues with using those. There is -also a mailing list run by some folks at Princeton University that might -be of help: https://lists.cs.princeton.edu/mailman/listinfo/ixp2xxx - -WHATEVER YOU DO, DO NOT POST EMAIL TO THE LINUX-ARM OR LINUX-ARM-KERNEL -MAILING LISTS REGARDING THE INTEL SDK. - -3. Supported Platforms - -- Intel IXDP2400 Reference Platform -- Intel IXDP2800 Reference Platform -- Intel IXDP2401 Reference Platform -- Intel IXDP2801 Reference Platform -- RadiSys ENP-2611 - -4. Usage Notes - -- The IXP2000 platforms usually have rather complex PCI bus topologies - with large memory space requirements. In addition, b/c of the way the - Intel SDK is designed, devices are enumerated in a very specific - way. B/c of this this, we use "pci=firmware" option in the kernel - command line so that we do not re-enumerate the bus. - -- IXDP2x01 systems have variable clock tick rates that we cannot determine - via HW registers. The "ixdp2x01_clk=XXX" cmd line options allow you - to pass the clock rate to the board port. - -5. Thanks - -The IXP2000 work has been funded by Intel Corp. and MontaVista Software, Inc. - -The following people have contributed patches/comments/etc: - -Naeem F. Afzal -Lennert Buytenhek -Jeffrey Daly - -------------------------------------------------------------------------- -Last Update: 8/09/2004 diff --git a/Documentation/arm/IXP4xx b/Documentation/arm/IXP4xx index 43edb4ecf27..e48b74de6ac 100644 --- a/Documentation/arm/IXP4xx +++ b/Documentation/arm/IXP4xx @@ -32,11 +32,11 @@ Linux currently supports the following features on the IXP4xx chips: - Flash access (MTD/JFFS) - I2C through GPIO on IXP42x - GPIO for input/output/interrupts - See include/asm-arm/arch-ixp4xx/platform.h for access functions. + See arch/arm/mach-ixp4xx/include/mach/platform.h for access functions. - Timers (watchdog, OS) The following components of the chips are not supported by Linux and -require the use of Intel's propietary CSR softare: +require the use of Intel's proprietary CSR software: - USB device interface - Network interfaces (HSS, Utopia, NPEs, etc) @@ -45,15 +45,15 @@ require the use of Intel's propietary CSR softare: If you need to use any of the above, you need to download Intel's software from: - http://developer.intel.com/design/network/products/npfamily/ixp425swr1.htm + http://developer.intel.com/design/network/products/npfamily/ixp425.htm -DO NOT POST QUESTIONS TO THE LINUX MAILING LISTS REGARDING THE PROPIETARY +DO NOT POST QUESTIONS TO THE LINUX MAILING LISTS REGARDING THE PROPRIETARY SOFTWARE. There are several websites that provide directions/pointers on using Intel's software: -http://ixp4xx-osdg.sourceforge.net/ + http://sourceforge.net/projects/ixp4xx-osdg/ Open Source Developer's Guide for using uClinux and the Intel libraries http://gatewaymaker.sourceforge.net/ @@ -112,21 +112,21 @@ http://www.adiengineering.com/productsCoyote.html Finally, there is an IDE port hanging off the expansion bus. Gateworks Avila Network Platform -http://www.gateworks.com/avila_sbc.htm +http://www.gateworks.com/support/overview.php The Avila platform is basically and IXDP425 with the 4 PCI slots replaced with mini-PCI slots and a CF IDE interface hanging off the expansion bus. Intel IXDP425 Development Platform -http://developer.intel.com/design/network/products/npfamily/ixdp425.htm +http://www.intel.com/design/network/products/npfamily/ixdpg425.htm This is Intel's standard reference platform for the IXDP425 and is also known as the Richfield board. It contains 4 PCI slots, 16MB of flash, two 10/100 ports and one ADSL port. Intel IXDP465 Development Platform -http://developer.intel.com/design/network/products/npfamily/ixdp465.htm +http://www.intel.com/design/network/products/npfamily/ixdp465.htm This is basically an IXDP425 with an IXP465 and 32M of flash instead of just 16. @@ -141,15 +141,13 @@ Intel IXDPG425 Development Platform a pivot_root to NFS. Motorola PrPMC1100 Processor Mezanine Card -http://www.fountainsys.com/datasheet/PrPMC1100.pdf +http://www.fountainsys.com The PrPMC1100 is based on the IXCP1100 and is meant to plug into and IXP2400/2800 system to act as the system controller. It simply contains a CPU and 16MB of flash on the board and needs to be plugged into a carrier board to function. Currently Linux only supports the Motorola PrPMC carrier board for this platform. - See https://mcg.motorola.com/us/ds/pdf/ds0144.pdf for info - on the carrier board. 5. TODO LIST diff --git a/Documentation/arm/Interrupts b/Documentation/arm/Interrupts index 0d3dbf1099b..f09ab1b90ef 100644 --- a/Documentation/arm/Interrupts +++ b/Documentation/arm/Interrupts @@ -138,14 +138,8 @@ So, what's changed? Set active the IRQ edge(s)/level. This replaces the SA1111 INTPOL manipulation, and the set_GPIO_IRQ_edge() - function. Type should be one of the following: - - #define IRQT_NOEDGE (0) - #define IRQT_RISING (__IRQT_RISEDGE) - #define IRQT_FALLING (__IRQT_FALEDGE) - #define IRQT_BOTHEDGE (__IRQT_RISEDGE|__IRQT_FALEDGE) - #define IRQT_LOW (__IRQT_LOWLVL) - #define IRQT_HIGH (__IRQT_HIGHLVL) + function. Type should be one of IRQ_TYPE_xxx defined in + <linux/irq.h> 3. set_GPIO_IRQ_edge() is obsolete, and should be replaced by set_irq_type. @@ -164,7 +158,7 @@ So, what's changed? be re-checked for pending events. (see the Neponset IRQ handler for details). -7. fixup_irq() is gone, as is include/asm-arm/arch-*/irq.h +7. fixup_irq() is gone, as is arch/arm/mach-*/include/mach/irq.h Please note that this will not solve all problems - some of them are hardware based. Mixing level-based and edge-based IRQs on the same diff --git a/Documentation/arm/Marvell/README b/Documentation/arm/Marvell/README new file mode 100644 index 00000000000..2cce5401e32 --- /dev/null +++ b/Documentation/arm/Marvell/README @@ -0,0 +1,272 @@ +ARM Marvell SoCs +================ + +This document lists all the ARM Marvell SoCs that are currently +supported in mainline by the Linux kernel. As the Marvell families of +SoCs are large and complex, it is hard to understand where the support +for a particular SoC is available in the Linux kernel. This document +tries to help in understanding where those SoCs are supported, and to +match them with their corresponding public datasheet, when available. + +Orion family +------------ + + Flavors: + 88F5082 + 88F5181 + 88F5181L + 88F5182 + Datasheet : http://www.embeddedarm.com/documentation/third-party/MV88F5182-datasheet.pdf + Programmer's User Guide : http://www.embeddedarm.com/documentation/third-party/MV88F5182-opensource-manual.pdf + User Manual : http://www.embeddedarm.com/documentation/third-party/MV88F5182-usermanual.pdf + 88F5281 + Datasheet : http://www.ocmodshop.com/images/reviews/networking/qnap_ts409u/marvel_88f5281_data_sheet.pdf + 88F6183 + Core: Feroceon ARMv5 compatible + Linux kernel mach directory: arch/arm/mach-orion5x + Linux kernel plat directory: arch/arm/plat-orion + +Kirkwood family +--------------- + + Flavors: + 88F6282 a.k.a Armada 300 + Product Brief : http://www.marvell.com/embedded-processors/armada-300/assets/armada_310.pdf + 88F6283 a.k.a Armada 310 + Product Brief : http://www.marvell.com/embedded-processors/armada-300/assets/armada_310.pdf + 88F6190 + Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6190-003_WEB.pdf + Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F619x_OpenSource.pdf + Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf + 88F6192 + Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6192-003_ver1.pdf + Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F619x_OpenSource.pdf + Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf + 88F6182 + 88F6180 + Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6180-003_ver1.pdf + Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F6180_OpenSource.pdf + Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf + 88F6281 + Product Brief : http://www.marvell.com/embedded-processors/kirkwood/assets/88F6281-004_ver1.pdf + Hardware Spec : http://www.marvell.com/embedded-processors/kirkwood/assets/HW_88F6281_OpenSource.pdf + Functional Spec: http://www.marvell.com/embedded-processors/kirkwood/assets/FS_88F6180_9x_6281_OpenSource.pdf + Homepage: http://www.marvell.com/embedded-processors/kirkwood/ + Core: Feroceon ARMv5 compatible + Linux kernel mach directory: arch/arm/mach-kirkwood + Linux kernel plat directory: arch/arm/plat-orion + +Discovery family +---------------- + + Flavors: + MV78100 + Product Brief : http://www.marvell.com/embedded-processors/discovery-innovation/assets/MV78100-003_WEB.pdf + Hardware Spec : http://www.marvell.com/embedded-processors/discovery-innovation/assets/HW_MV78100_OpenSource.pdf + Functional Spec: http://www.marvell.com/embedded-processors/discovery-innovation/assets/FS_MV76100_78100_78200_OpenSource.pdf + MV78200 + Product Brief : http://www.marvell.com/embedded-processors/discovery-innovation/assets/MV78200-002_WEB.pdf + Hardware Spec : http://www.marvell.com/embedded-processors/discovery-innovation/assets/HW_MV78200_OpenSource.pdf + Functional Spec: http://www.marvell.com/embedded-processors/discovery-innovation/assets/FS_MV76100_78100_78200_OpenSource.pdf + MV76100 + Not supported by the Linux kernel. + + Core: Feroceon ARMv5 compatible + + Linux kernel mach directory: arch/arm/mach-mv78xx0 + Linux kernel plat directory: arch/arm/plat-orion + +EBU Armada family +----------------- + + Armada 370 Flavors: + 88F6710 + 88F6707 + 88F6W11 + Product Brief: http://www.marvell.com/embedded-processors/armada-300/assets/Marvell_ARMADA_370_SoC.pdf + + Armada 375 Flavors: + 88F6720 + Product Brief: http://www.marvell.com/embedded-processors/armada-300/assets/ARMADA_375_SoC-01_product_brief.pdf + + Armada 380/385 Flavors: + 88F6810 + 88F6820 + 88F6828 + + Armada XP Flavors: + MV78230 + MV78260 + MV78460 + NOTE: not to be confused with the non-SMP 78xx0 SoCs + Product Brief: http://www.marvell.com/embedded-processors/armada-xp/assets/Marvell-ArmadaXP-SoC-product%20brief.pdf + + No public datasheet available. + + Core: Sheeva ARMv7 compatible + + Linux kernel mach directory: arch/arm/mach-mvebu + Linux kernel plat directory: none + +Avanta family +------------- + + Flavors: + 88F6510 + 88F6530P + 88F6550 + 88F6560 + Homepage : http://www.marvell.com/broadband/ + Product Brief: http://www.marvell.com/broadband/assets/Marvell_Avanta_88F6510_305_060-001_product_brief.pdf + No public datasheet available. + + Core: ARMv5 compatible + + Linux kernel mach directory: no code in mainline yet, planned for the future + Linux kernel plat directory: no code in mainline yet, planned for the future + +Dove family (application processor) +----------------------------------- + + Flavors: + 88AP510 a.k.a Armada 510 + Product Brief : http://www.marvell.com/application-processors/armada-500/assets/Marvell_Armada510_SoC.pdf + Hardware Spec : http://www.marvell.com/application-processors/armada-500/assets/Armada-510-Hardware-Spec.pdf + Functional Spec : http://www.marvell.com/application-processors/armada-500/assets/Armada-510-Functional-Spec.pdf + Homepage: http://www.marvell.com/application-processors/armada-500/ + Core: ARMv7 compatible + Directory: arch/arm/mach-dove + +PXA 2xx/3xx/93x/95x family +-------------------------- + + Flavors: + PXA21x, PXA25x, PXA26x + Application processor only + Core: ARMv5 XScale core + PXA270, PXA271, PXA272 + Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_pb.pdf + Design guide : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_design_guide.pdf + Developers manual : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_dev_man.pdf + Specification : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_emts.pdf + Specification update : http://www.marvell.com/application-processors/pxa-family/assets/pxa_27x_spec_update.pdf + Application processor only + Core: ARMv5 XScale core + PXA300, PXA310, PXA320 + PXA 300 Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/PXA300_PB_R4.pdf + PXA 310 Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/PXA310_PB_R4.pdf + PXA 320 Product Brief : http://www.marvell.com/application-processors/pxa-family/assets/PXA320_PB_R4.pdf + Design guide : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_Design_Guide.pdf + Developers manual : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_Developers_Manual.zip + Specifications : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_EMTS.pdf + Specification Update : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_Spec_Update.zip + Reference Manual : http://www.marvell.com/application-processors/pxa-family/assets/PXA3xx_TavorP_BootROM_Ref_Manual.pdf + Application processor only + Core: ARMv5 XScale core + PXA930, PXA935 + Application processor with Communication processor + Core: ARMv5 XScale core + PXA955 + Application processor with Communication processor + Core: ARMv7 compatible Sheeva PJ4 core + + Comments: + + * This line of SoCs originates from the XScale family developed by + Intel and acquired by Marvell in ~2006. The PXA21x, PXA25x, + PXA26x, PXA27x, PXA3xx and PXA93x were developed by Intel, while + the later PXA95x were developed by Marvell. + + * Due to their XScale origin, these SoCs have virtually nothing in + common with the other (Kirkwood, Dove, etc.) families of Marvell + SoCs, except with the MMP/MMP2 family of SoCs. + + Linux kernel mach directory: arch/arm/mach-pxa + Linux kernel plat directory: arch/arm/plat-pxa + +MMP/MMP2 family (communication processor) +----------------------------------------- + + Flavors: + PXA168, a.k.a Armada 168 + Homepage : http://www.marvell.com/application-processors/armada-100/armada-168.jsp + Product brief : http://www.marvell.com/application-processors/armada-100/assets/pxa_168_pb.pdf + Hardware manual : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_datasheet.pdf + Software manual : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_software_manual.pdf + Specification update : http://www.marvell.com/application-processors/armada-100/assets/ARMADA16x_Spec_update.pdf + Boot ROM manual : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_ref_manual.pdf + App node package : http://www.marvell.com/application-processors/armada-100/assets/armada_16x_app_note_package.pdf + Application processor only + Core: ARMv5 compatible Marvell PJ1 (Mohawk) + PXA910 + Homepage : http://www.marvell.com/communication-processors/pxa910/ + Product Brief : http://www.marvell.com/communication-processors/pxa910/assets/Marvell_PXA910_Platform-001_PB_final.pdf + Application processor with Communication processor + Core: ARMv5 compatible Marvell PJ1 (Mohawk) + MMP2, a.k.a Armada 610 + Product Brief : http://www.marvell.com/application-processors/armada-600/assets/armada610_pb.pdf + Application processor only + Core: ARMv7 compatible Sheeva PJ4 core + + Comments: + + * This line of SoCs originates from the XScale family developed by + Intel and acquired by Marvell in ~2006. All the processors of + this MMP/MMP2 family were developed by Marvell. + + * Due to their XScale origin, these SoCs have virtually nothing in + common with the other (Kirkwood, Dove, etc.) families of Marvell + SoCs, except with the PXA family of SoCs listed above. + + Linux kernel mach directory: arch/arm/mach-mmp + Linux kernel plat directory: arch/arm/plat-pxa + +Berlin family (Digital Entertainment) +------------------------------------- + + Flavors: + 88DE3005, Armada 1500-mini + Design name: BG2CD + Core: ARM Cortex-A9, PL310 L2CC + Homepage: http://www.marvell.com/digital-entertainment/armada-1500-mini/ + 88DE3100, Armada 1500 + Design name: BG2 + Core: Marvell PJ4B (ARMv7), Tauros3 L2CC + Homepage: http://www.marvell.com/digital-entertainment/armada-1500/ + Product Brief: http://www.marvell.com/digital-entertainment/armada-1500/assets/Marvell-ARMADA-1500-Product-Brief.pdf + 88DE3114, Armada 1500 Pro + Design name: BG2-Q + Core: Quad Core ARM Cortex-A9, PL310 L2CC + Homepage: http://www.marvell.com/digital-entertainment/armada-1500-pro/ + Product Brief: http://www.marvell.com/digital-entertainment/armada-1500-pro/assets/Marvell_ARMADA_1500_PRO-01_product_brief.pdf + 88DE???? + Design name: BG3 + Core: ARM Cortex-A15, CA15 integrated L2CC + + Homepage: http://www.marvell.com/digital-entertainment/ + Directory: arch/arm/mach-berlin + + Comments: + * This line of SoCs is based on Marvell Sheeva or ARM Cortex CPUs + with Synopsys DesignWare (IRQ, GPIO, Timers, ...) and PXA IP (SDHCI, USB, ETH, ...). + +Long-term plans +--------------- + + * Unify the mach-dove/, mach-mv78xx0/, mach-orion5x/ and + mach-kirkwood/ into the mach-mvebu/ to support all SoCs from the + Marvell EBU (Engineering Business Unit) in a single mach-<foo> + directory. The plat-orion/ would therefore disappear. + + * Unify the mach-mmp/ and mach-pxa/ into the same mach-pxa + directory. The plat-pxa/ would therefore disappear. + +Credits +------- + + Maen Suleiman <maen@marvell.com> + Lior Amsalem <alior@marvell.com> + Thomas Petazzoni <thomas.petazzoni@free-electrons.com> + Andrew Lunn <andrew@lunn.ch> + Nicolas Pitre <nico@fluxnic.net> + Eric Miao <eric.y.miao@gmail.com> diff --git a/Documentation/arm/OMAP/DSS b/Documentation/arm/OMAP/DSS new file mode 100644 index 00000000000..4484e021290 --- /dev/null +++ b/Documentation/arm/OMAP/DSS @@ -0,0 +1,362 @@ +OMAP2/3 Display Subsystem +------------------------- + +This is an almost total rewrite of the OMAP FB driver in drivers/video/omap +(let's call it DSS1). The main differences between DSS1 and DSS2 are DSI, +TV-out and multiple display support, but there are lots of small improvements +also. + +The DSS2 driver (omapdss module) is in arch/arm/plat-omap/dss/, and the FB, +panel and controller drivers are in drivers/video/omap2/. DSS1 and DSS2 live +currently side by side, you can choose which one to use. + +Features +-------- + +Working and tested features include: + +- MIPI DPI (parallel) output +- MIPI DSI output in command mode +- MIPI DBI (RFBI) output +- SDI output +- TV output +- All pieces can be compiled as a module or inside kernel +- Use DISPC to update any of the outputs +- Use CPU to update RFBI or DSI output +- OMAP DISPC planes +- RGB16, RGB24 packed, RGB24 unpacked +- YUV2, UYVY +- Scaling +- Adjusting DSS FCK to find a good pixel clock +- Use DSI DPLL to create DSS FCK + +Tested boards include: +- OMAP3 SDP board +- Beagle board +- N810 + +omapdss driver +-------------- + +The DSS driver does not itself have any support for Linux framebuffer, V4L or +such like the current ones, but it has an internal kernel API that upper level +drivers can use. + +The DSS driver models OMAP's overlays, overlay managers and displays in a +flexible way to enable non-common multi-display configuration. In addition to +modelling the hardware overlays, omapdss supports virtual overlays and overlay +managers. These can be used when updating a display with CPU or system DMA. + +omapdss driver support for audio +-------------------------------- +There exist several display technologies and standards that support audio as +well. Hence, it is relevant to update the DSS device driver to provide an audio +interface that may be used by an audio driver or any other driver interested in +the functionality. + +The audio_enable function is intended to prepare the relevant +IP for playback (e.g., enabling an audio FIFO, taking in/out of reset +some IP, enabling companion chips, etc). It is intended to be called before +audio_start. The audio_disable function performs the reverse operation and is +intended to be called after audio_stop. + +While a given DSS device driver may support audio, it is possible that for +certain configurations audio is not supported (e.g., an HDMI display using a +VESA video timing). The audio_supported function is intended to query whether +the current configuration of the display supports audio. + +The audio_config function is intended to configure all the relevant audio +parameters of the display. In order to make the function independent of any +specific DSS device driver, a struct omap_dss_audio is defined. Its purpose +is to contain all the required parameters for audio configuration. At the +moment, such structure contains pointers to IEC-60958 channel status word +and CEA-861 audio infoframe structures. This should be enough to support +HDMI and DisplayPort, as both are based on CEA-861 and IEC-60958. + +The audio_enable/disable, audio_config and audio_supported functions could be +implemented as functions that may sleep. Hence, they should not be called +while holding a spinlock or a readlock. + +The audio_start/audio_stop function is intended to effectively start/stop audio +playback after the configuration has taken place. These functions are designed +to be used in an atomic context. Hence, audio_start should return quickly and be +called only after all the needed resources for audio playback (audio FIFOs, +DMA channels, companion chips, etc) have been enabled to begin data transfers. +audio_stop is designed to only stop the audio transfers. The resources used +for playback are released using audio_disable. + +The enum omap_dss_audio_state may be used to help the implementations of +the interface to keep track of the audio state. The initial state is _DISABLED; +then, the state transitions to _CONFIGURED, and then, when it is ready to +play audio, to _ENABLED. The state _PLAYING is used when the audio is being +rendered. + + +Panel and controller drivers +---------------------------- + +The drivers implement panel or controller specific functionality and are not +usually visible to users except through omapfb driver. They register +themselves to the DSS driver. + +omapfb driver +------------- + +The omapfb driver implements arbitrary number of standard linux framebuffers. +These framebuffers can be routed flexibly to any overlays, thus allowing very +dynamic display architecture. + +The driver exports some omapfb specific ioctls, which are compatible with the +ioctls in the old driver. + +The rest of the non standard features are exported via sysfs. Whether the final +implementation will use sysfs, or ioctls, is still open. + +V4L2 drivers +------------ + +V4L2 is being implemented in TI. + +From omapdss point of view the V4L2 drivers should be similar to framebuffer +driver. + +Architecture +-------------------- + +Some clarification what the different components do: + + - Framebuffer is a memory area inside OMAP's SRAM/SDRAM that contains the + pixel data for the image. Framebuffer has width and height and color + depth. + - Overlay defines where the pixels are read from and where they go on the + screen. The overlay may be smaller than framebuffer, thus displaying only + part of the framebuffer. The position of the overlay may be changed if + the overlay is smaller than the display. + - Overlay manager combines the overlays in to one image and feeds them to + display. + - Display is the actual physical display device. + +A framebuffer can be connected to multiple overlays to show the same pixel data +on all of the overlays. Note that in this case the overlay input sizes must be +the same, but, in case of video overlays, the output size can be different. Any +framebuffer can be connected to any overlay. + +An overlay can be connected to one overlay manager. Also DISPC overlays can be +connected only to DISPC overlay managers, and virtual overlays can be only +connected to virtual overlays. + +An overlay manager can be connected to one display. There are certain +restrictions which kinds of displays an overlay manager can be connected: + + - DISPC TV overlay manager can be only connected to TV display. + - Virtual overlay managers can only be connected to DBI or DSI displays. + - DISPC LCD overlay manager can be connected to all displays, except TV + display. + +Sysfs +----- +The sysfs interface is mainly used for testing. I don't think sysfs +interface is the best for this in the final version, but I don't quite know +what would be the best interfaces for these things. + +The sysfs interface is divided to two parts: DSS and FB. + +/sys/class/graphics/fb? directory: +mirror 0=off, 1=on +rotate Rotation 0-3 for 0, 90, 180, 270 degrees +rotate_type 0 = DMA rotation, 1 = VRFB rotation +overlays List of overlay numbers to which framebuffer pixels go +phys_addr Physical address of the framebuffer +virt_addr Virtual address of the framebuffer +size Size of the framebuffer + +/sys/devices/platform/omapdss/overlay? directory: +enabled 0=off, 1=on +input_size width,height (ie. the framebuffer size) +manager Destination overlay manager name +name +output_size width,height +position x,y +screen_width width +global_alpha global alpha 0-255 0=transparent 255=opaque + +/sys/devices/platform/omapdss/manager? directory: +display Destination display +name +alpha_blending_enabled 0=off, 1=on +trans_key_enabled 0=off, 1=on +trans_key_type gfx-destination, video-source +trans_key_value transparency color key (RGB24) +default_color default background color (RGB24) + +/sys/devices/platform/omapdss/display? directory: +ctrl_name Controller name +mirror 0=off, 1=on +update_mode 0=off, 1=auto, 2=manual +enabled 0=off, 1=on +name +rotate Rotation 0-3 for 0, 90, 180, 270 degrees +timings Display timings (pixclock,xres/hfp/hbp/hsw,yres/vfp/vbp/vsw) + When writing, two special timings are accepted for tv-out: + "pal" and "ntsc" +panel_name +tear_elim Tearing elimination 0=off, 1=on +output_type Output type (video encoder only): "composite" or "svideo" + +There are also some debugfs files at <debugfs>/omapdss/ which show information +about clocks and registers. + +Examples +-------- + +The following definitions have been made for the examples below: + +ovl0=/sys/devices/platform/omapdss/overlay0 +ovl1=/sys/devices/platform/omapdss/overlay1 +ovl2=/sys/devices/platform/omapdss/overlay2 + +mgr0=/sys/devices/platform/omapdss/manager0 +mgr1=/sys/devices/platform/omapdss/manager1 + +lcd=/sys/devices/platform/omapdss/display0 +dvi=/sys/devices/platform/omapdss/display1 +tv=/sys/devices/platform/omapdss/display2 + +fb0=/sys/class/graphics/fb0 +fb1=/sys/class/graphics/fb1 +fb2=/sys/class/graphics/fb2 + +Default setup on OMAP3 SDP +-------------------------- + +Here's the default setup on OMAP3 SDP board. All planes go to LCD. DVI +and TV-out are not in use. The columns from left to right are: +framebuffers, overlays, overlay managers, displays. Framebuffers are +handled by omapfb, and the rest by the DSS. + +FB0 --- GFX -\ DVI +FB1 --- VID1 --+- LCD ---- LCD +FB2 --- VID2 -/ TV ----- TV + +Example: Switch from LCD to DVI +---------------------- + +w=`cat $dvi/timings | cut -d "," -f 2 | cut -d "/" -f 1` +h=`cat $dvi/timings | cut -d "," -f 3 | cut -d "/" -f 1` + +echo "0" > $lcd/enabled +echo "" > $mgr0/display +fbset -fb /dev/fb0 -xres $w -yres $h -vxres $w -vyres $h +# at this point you have to switch the dvi/lcd dip-switch from the omap board +echo "dvi" > $mgr0/display +echo "1" > $dvi/enabled + +After this the configuration looks like: + +FB0 --- GFX -\ -- DVI +FB1 --- VID1 --+- LCD -/ LCD +FB2 --- VID2 -/ TV ----- TV + +Example: Clone GFX overlay to LCD and TV +------------------------------- + +w=`cat $tv/timings | cut -d "," -f 2 | cut -d "/" -f 1` +h=`cat $tv/timings | cut -d "," -f 3 | cut -d "/" -f 1` + +echo "0" > $ovl0/enabled +echo "0" > $ovl1/enabled + +echo "" > $fb1/overlays +echo "0,1" > $fb0/overlays + +echo "$w,$h" > $ovl1/output_size +echo "tv" > $ovl1/manager + +echo "1" > $ovl0/enabled +echo "1" > $ovl1/enabled + +echo "1" > $tv/enabled + +After this the configuration looks like (only relevant parts shown): + +FB0 +-- GFX ---- LCD ---- LCD + \- VID1 ---- TV ---- TV + +Misc notes +---------- + +OMAP FB allocates the framebuffer memory using the standard dma allocator. You +can enable Contiguous Memory Allocator (CONFIG_CMA) to improve the dma +allocator, and if CMA is enabled, you use "cma=" kernel parameter to increase +the global memory area for CMA. + +Using DSI DPLL to generate pixel clock it is possible produce the pixel clock +of 86.5MHz (max possible), and with that you get 1280x1024@57 output from DVI. + +Rotation and mirroring currently only supports RGB565 and RGB8888 modes. VRFB +does not support mirroring. + +VRFB rotation requires much more memory than non-rotated framebuffer, so you +probably need to increase your vram setting before using VRFB rotation. Also, +many applications may not work with VRFB if they do not pay attention to all +framebuffer parameters. + +Kernel boot arguments +--------------------- + +omapfb.mode=<display>:<mode>[,...] + - Default video mode for specified displays. For example, + "dvi:800x400MR-24@60". See drivers/video/modedb.c. + There are also two special modes: "pal" and "ntsc" that + can be used to tv out. + +omapfb.vram=<fbnum>:<size>[@<physaddr>][,...] + - VRAM allocated for a framebuffer. Normally omapfb allocates vram + depending on the display size. With this you can manually allocate + more or define the physical address of each framebuffer. For example, + "1:4M" to allocate 4M for fb1. + +omapfb.debug=<y|n> + - Enable debug printing. You have to have OMAPFB debug support enabled + in kernel config. + +omapfb.test=<y|n> + - Draw test pattern to framebuffer whenever framebuffer settings change. + You need to have OMAPFB debug support enabled in kernel config. + +omapfb.vrfb=<y|n> + - Use VRFB rotation for all framebuffers. + +omapfb.rotate=<angle> + - Default rotation applied to all framebuffers. + 0 - 0 degree rotation + 1 - 90 degree rotation + 2 - 180 degree rotation + 3 - 270 degree rotation + +omapfb.mirror=<y|n> + - Default mirror for all framebuffers. Only works with DMA rotation. + +omapdss.def_disp=<display> + - Name of default display, to which all overlays will be connected. + Common examples are "lcd" or "tv". + +omapdss.debug=<y|n> + - Enable debug printing. You have to have DSS debug support enabled in + kernel config. + +TODO +---- + +DSS locking + +Error checking +- Lots of checks are missing or implemented just as BUG() + +System DMA update for DSI +- Can be used for RGB16 and RGB24P modes. Probably not for RGB24U (how + to skip the empty byte?) + +OMAP1 support +- Not sure if needed + diff --git a/Documentation/arm/OMAP/omap_pm b/Documentation/arm/OMAP/omap_pm new file mode 100644 index 00000000000..4ae915a9f89 --- /dev/null +++ b/Documentation/arm/OMAP/omap_pm @@ -0,0 +1,154 @@ + +The OMAP PM interface +===================== + +This document describes the temporary OMAP PM interface. Driver +authors use these functions to communicate minimum latency or +throughput constraints to the kernel power management code. +Over time, the intention is to merge features from the OMAP PM +interface into the Linux PM QoS code. + +Drivers need to express PM parameters which: + +- support the range of power management parameters present in the TI SRF; + +- separate the drivers from the underlying PM parameter + implementation, whether it is the TI SRF or Linux PM QoS or Linux + latency framework or something else; + +- specify PM parameters in terms of fundamental units, such as + latency and throughput, rather than units which are specific to OMAP + or to particular OMAP variants; + +- allow drivers which are shared with other architectures (e.g., + DaVinci) to add these constraints in a way which won't affect non-OMAP + systems, + +- can be implemented immediately with minimal disruption of other + architectures. + + +This document proposes the OMAP PM interface, including the following +five power management functions for driver code: + +1. Set the maximum MPU wakeup latency: + (*pdata->set_max_mpu_wakeup_lat)(struct device *dev, unsigned long t) + +2. Set the maximum device wakeup latency: + (*pdata->set_max_dev_wakeup_lat)(struct device *dev, unsigned long t) + +3. Set the maximum system DMA transfer start latency (CORE pwrdm): + (*pdata->set_max_sdma_lat)(struct device *dev, long t) + +4. Set the minimum bus throughput needed by a device: + (*pdata->set_min_bus_tput)(struct device *dev, u8 agent_id, unsigned long r) + +5. Return the number of times the device has lost context + (*pdata->get_dev_context_loss_count)(struct device *dev) + + +Further documentation for all OMAP PM interface functions can be +found in arch/arm/plat-omap/include/mach/omap-pm.h. + + +The OMAP PM layer is intended to be temporary +--------------------------------------------- + +The intention is that eventually the Linux PM QoS layer should support +the range of power management features present in OMAP3. As this +happens, existing drivers using the OMAP PM interface can be modified +to use the Linux PM QoS code; and the OMAP PM interface can disappear. + + +Driver usage of the OMAP PM functions +------------------------------------- + +As the 'pdata' in the above examples indicates, these functions are +exposed to drivers through function pointers in driver .platform_data +structures. The function pointers are initialized by the board-*.c +files to point to the corresponding OMAP PM functions: +.set_max_dev_wakeup_lat will point to +omap_pm_set_max_dev_wakeup_lat(), etc. Other architectures which do +not support these functions should leave these function pointers set +to NULL. Drivers should use the following idiom: + + if (pdata->set_max_dev_wakeup_lat) + (*pdata->set_max_dev_wakeup_lat)(dev, t); + +The most common usage of these functions will probably be to specify +the maximum time from when an interrupt occurs, to when the device +becomes accessible. To accomplish this, driver writers should use the +set_max_mpu_wakeup_lat() function to constrain the MPU wakeup +latency, and the set_max_dev_wakeup_lat() function to constrain the +device wakeup latency (from clk_enable() to accessibility). For +example, + + /* Limit MPU wakeup latency */ + if (pdata->set_max_mpu_wakeup_lat) + (*pdata->set_max_mpu_wakeup_lat)(dev, tc); + + /* Limit device powerdomain wakeup latency */ + if (pdata->set_max_dev_wakeup_lat) + (*pdata->set_max_dev_wakeup_lat)(dev, td); + + /* total wakeup latency in this example: (tc + td) */ + +The PM parameters can be overwritten by calling the function again +with the new value. The settings can be removed by calling the +function with a t argument of -1 (except in the case of +set_max_bus_tput(), which should be called with an r argument of 0). + +The fifth function above, omap_pm_get_dev_context_loss_count(), +is intended as an optimization to allow drivers to determine whether the +device has lost its internal context. If context has been lost, the +driver must restore its internal context before proceeding. + + +Other specialized interface functions +------------------------------------- + +The five functions listed above are intended to be usable by any +device driver. DSPBridge and CPUFreq have a few special requirements. +DSPBridge expresses target DSP performance levels in terms of OPP IDs. +CPUFreq expresses target MPU performance levels in terms of MPU +frequency. The OMAP PM interface contains functions for these +specialized cases to convert that input information (OPPs/MPU +frequency) into the form that the underlying power management +implementation needs: + +6. (*pdata->dsp_get_opp_table)(void) + +7. (*pdata->dsp_set_min_opp)(u8 opp_id) + +8. (*pdata->dsp_get_opp)(void) + +9. (*pdata->cpu_get_freq_table)(void) + +10. (*pdata->cpu_set_freq)(unsigned long f) + +11. (*pdata->cpu_get_freq)(void) + +Customizing OPP for platform +============================ +Defining CONFIG_PM should enable OPP layer for the silicon +and the registration of OPP table should take place automatically. +However, in special cases, the default OPP table may need to be +tweaked, for e.g.: + * enable default OPPs which are disabled by default, but which + could be enabled on a platform + * Disable an unsupported OPP on the platform + * Define and add a custom opp table entry +in these cases, the board file needs to do additional steps as follows: +arch/arm/mach-omapx/board-xyz.c + #include "pm.h" + .... + static void __init omap_xyz_init_irq(void) + { + .... + /* Initialize the default table */ + omapx_opp_init(); + /* Do customization to the defaults */ + .... + } +NOTE: omapx_opp_init will be omap3_opp_init or as required +based on the omap family. diff --git a/Documentation/arm/README b/Documentation/arm/README index 9b9c8226fdc..aea34095cdc 100644 --- a/Documentation/arm/README +++ b/Documentation/arm/README @@ -41,12 +41,12 @@ Bug reports etc --------------- Please send patches to the patch system. For more information, see - http://www.arm.linux.org.uk/patches/info.html Always include some + http://www.arm.linux.org.uk/developer/patches/info.php Always include some explanation as to what the patch does and why it is needed. Bug reports should be sent to linux-arm-kernel@lists.arm.linux.org.uk, or submitted through the web form at - http://www.arm.linux.org.uk/forms/solution.shtml + http://www.arm.linux.org.uk/developer/ When sending bug reports, please ensure that they contain all relevant information, eg. the kernel messages that were printed before/during @@ -79,7 +79,7 @@ Machine/Platform support To this end, we now have arch/arm/mach-$(MACHINE) directories which are designed to house the non-driver files for a particular machine (eg, PCI, memory management, architecture definitions etc). For all future - machines, there should be a corresponding include/asm-arm/arch-$(MACHINE) + machines, there should be a corresponding arch/arm/mach-$(MACHINE)/include/mach directory. @@ -176,7 +176,7 @@ Kernel entry (head.S) class typically based around one or more system on a chip devices, and acts as a natural container around the actual implementations. These classes are given directories - arch/arm/mach-<class> and - include/asm-arm/arch-<class> - which contain the source files to + arch/arm/mach-<class> - which contain the source files to/include/mach support the machine class. This directories also contain any machine specific supporting code. diff --git a/Documentation/arm/SA1100/ADSBitsy b/Documentation/arm/SA1100/ADSBitsy index ab47c383390..f9f62e8c071 100644 --- a/Documentation/arm/SA1100/ADSBitsy +++ b/Documentation/arm/SA1100/ADSBitsy @@ -32,7 +32,7 @@ Notes: - The flash on board is divided into 3 partitions. You should be careful to use flash on board. - It's partition is different from GraphicsClient Plus and GraphicsMaster + Its partition is different from GraphicsClient Plus and GraphicsMaster - 16bpp mode requires a different cable than what ships with the board. Contact ADS or look through the manual to wire your own. Currently, @@ -40,4 +40,4 @@ Notes: mode, the timing is off so the image is corrupted. This will be fixed soon. -Any contribution can be sent to nico@cam.org and will be greatly welcome! +Any contribution can be sent to nico@fluxnic.net and will be greatly welcome! diff --git a/Documentation/arm/SA1100/Assabet b/Documentation/arm/SA1100/Assabet index 78bc1c1b04e..08b885d3567 100644 --- a/Documentation/arm/SA1100/Assabet +++ b/Documentation/arm/SA1100/Assabet @@ -2,8 +2,7 @@ The Intel Assabet (SA-1110 evaluation) board ============================================ Please see: -http://developer.intel.com/design/strong/quicklist/eval-plat/sa-1110.htm -http://developer.intel.com/design/strong/guides/278278.htm +http://developer.intel.com Also some notes from John G Dorsey <jd5q@andrew.cmu.edu>: http://www.cs.cmu.edu/~wearable/software/assabet.html @@ -64,7 +63,7 @@ Initial RedBoot configuration ----------------------------- The commands used here are explained in The RedBoot User's Guide available -on-line at http://sources.redhat.com/ecos/docs-latest/redboot/redboot.html. +on-line at http://sources.redhat.com/ecos/docs.html. Please refer to it for explanations. If you have a CF network card (my Assabet kit contained a CF+ LP-E from @@ -240,7 +239,7 @@ Then, rebooting the Assabet is just a matter of waiting for the login prompt. Nicolas Pitre -nico@cam.org +nico@fluxnic.net June 12, 2001 diff --git a/Documentation/arm/SA1100/Brutus b/Documentation/arm/SA1100/Brutus index 2254c8f0b32..6a3aa95e9bf 100644 --- a/Documentation/arm/SA1100/Brutus +++ b/Documentation/arm/SA1100/Brutus @@ -1,7 +1,7 @@ Brutus is an evaluation platform for the SA1100 manufactured by Intel. For more details, see: -http://developer.intel.com/design/strong/applnots/sa1100lx/getstart.htm +http://developer.intel.com To compile for Brutus, you must issue the following commands: @@ -60,7 +60,7 @@ little modifications. Any contribution is welcome. -Please send patches to nico@cam.org +Please send patches to nico@fluxnic.net Have Fun ! diff --git a/Documentation/arm/SA1100/FreeBird b/Documentation/arm/SA1100/FreeBird index eda28b3232e..ab9193663b2 100644 --- a/Documentation/arm/SA1100/FreeBird +++ b/Documentation/arm/SA1100/FreeBird @@ -1,6 +1,6 @@ -Freebird-1.1 is produced by Legned(C) ,Inc. -(http://www.legend.com.cn) -and software/linux mainatined by Coventive(C),Inc. +Freebird-1.1 is produced by Legend(C), Inc. +http://web.archive.org/web/*/http://www.legend.com.cn +and software/linux maintained by Coventive(C), Inc. (http://www.coventive.com) Based on the Nicolas's strongarm kernel tree. diff --git a/Documentation/arm/SA1100/GraphicsClient b/Documentation/arm/SA1100/GraphicsClient index 8fa7e8027ff..867bb35943a 100644 --- a/Documentation/arm/SA1100/GraphicsClient +++ b/Documentation/arm/SA1100/GraphicsClient @@ -4,7 +4,7 @@ For more details, contact Applied Data Systems or see http://www.applieddata.net/products.html The original Linux support for this product has been provided by -Nicolas Pitre <nico@cam.org>. Continued development work by +Nicolas Pitre <nico@fluxnic.net>. Continued development work by Woojung Huh <whuh@applieddata.net> It's currently possible to mount a root filesystem via NFS providing a @@ -71,7 +71,7 @@ Supported peripherals: - serial ports (ttyS[0-2]) - ttyS0 is default for serial console - Smart I/O (ADC, keypad, digital inputs, etc) - See http://www.applieddata.com/developers/linux for IOCTL documentation + See http://www.eurotech-inc.com/linux-sbc.asp for IOCTL documentation and example user space code. ps/2 keybd is multiplexed through this driver To do: @@ -94,5 +94,5 @@ Notes: mode, the timing is off so the image is corrupted. This will be fixed soon. -Any contribution can be sent to nico@cam.org and will be greatly welcome! +Any contribution can be sent to nico@fluxnic.net and will be greatly welcome! diff --git a/Documentation/arm/SA1100/GraphicsMaster b/Documentation/arm/SA1100/GraphicsMaster index dd28745ac52..9145088a0ba 100644 --- a/Documentation/arm/SA1100/GraphicsMaster +++ b/Documentation/arm/SA1100/GraphicsMaster @@ -4,7 +4,7 @@ For more details, contact Applied Data Systems or see http://www.applieddata.net/products.html The original Linux support for this product has been provided by -Nicolas Pitre <nico@cam.org>. Continued development work by +Nicolas Pitre <nico@fluxnic.net>. Continued development work by Woojung Huh <whuh@applieddata.net> Use 'make graphicsmaster_config' before any 'make config'. @@ -28,7 +28,7 @@ Supported peripherals: - serial ports (ttyS[0-2]) - ttyS0 is default for serial console - Smart I/O (ADC, keypad, digital inputs, etc) - See http://www.applieddata.com/developers/linux for IOCTL documentation + See http://www.eurotech-inc.com/linux-sbc.asp for IOCTL documentation and example user space code. ps/2 keybd is multiplexed through this driver To do: @@ -50,4 +50,4 @@ Notes: mode, the timing is off so the image is corrupted. This will be fixed soon. -Any contribution can be sent to nico@cam.org and will be greatly welcome! +Any contribution can be sent to nico@fluxnic.net and will be greatly welcome! diff --git a/Documentation/arm/SA1100/Itsy b/Documentation/arm/SA1100/Itsy index 3b594534323..44b94997fa0 100644 --- a/Documentation/arm/SA1100/Itsy +++ b/Documentation/arm/SA1100/Itsy @@ -4,7 +4,7 @@ research projects at Compaq that are related to pocket computing. For more information, see: - http://www.research.digital.com/wrl/itsy/index.html + http://www.hpl.hp.com/downloads/crl/itsy/ Notes on initial 2.4 Itsy support (8/27/2000) : The port was done on an Itsy version 1.5 machine with a daughtercard with diff --git a/Documentation/arm/SA1100/PLEB b/Documentation/arm/SA1100/PLEB index 92cae066908..b9c8a631a35 100644 --- a/Documentation/arm/SA1100/PLEB +++ b/Documentation/arm/SA1100/PLEB @@ -6,6 +6,6 @@ PLEB support has yet to be fully integrated. For more information, see: - http://www.cse.unsw.edu.au/~pleb/ + http://www.cse.unsw.edu.au diff --git a/Documentation/arm/SA1100/Victor b/Documentation/arm/SA1100/Victor index 01e81fc4946..9cff415da5a 100644 --- a/Documentation/arm/SA1100/Victor +++ b/Documentation/arm/SA1100/Victor @@ -3,13 +3,13 @@ VisuAide, Inc. to be used by blind people. For more information related to Victor, see: - http://www.visuaide.com/victor + http://www.humanware.com/en-usa/products Of course Victor is using Linux as its main operating system. The Victor implementation for Linux is maintained by Nicolas Pitre: nico@visuaide.com - nico@cam.org + nico@fluxnic.net For any comments, please feel free to contact me through the above addresses. diff --git a/Documentation/arm/SA1100/nanoEngine b/Documentation/arm/SA1100/nanoEngine index fc431cbfefc..48a7934f95f 100644 --- a/Documentation/arm/SA1100/nanoEngine +++ b/Documentation/arm/SA1100/nanoEngine @@ -7,5 +7,5 @@ for more info. (Ref: Stuart Adams <sja@brightstareng.com>) Also visit Larry Doolittle's "Linux for the nanoEngine" site: -http://recycle.lbl.gov/~ldoolitt/bse/ +http://www.brightstareng.com/arm/nanoeng.htm diff --git a/Documentation/arm/SH-Mobile/Makefile b/Documentation/arm/SH-Mobile/Makefile new file mode 100644 index 00000000000..8771d832cf8 --- /dev/null +++ b/Documentation/arm/SH-Mobile/Makefile @@ -0,0 +1,8 @@ +BIN := vrl4 + +.PHONY: all +all: $(BIN) + +.PHONY: clean +clean: + rm -f *.o $(BIN) diff --git a/Documentation/arm/SH-Mobile/vrl4.c b/Documentation/arm/SH-Mobile/vrl4.c new file mode 100644 index 00000000000..e8a191358ad --- /dev/null +++ b/Documentation/arm/SH-Mobile/vrl4.c @@ -0,0 +1,169 @@ +/* + * vrl4 format generator + * + * Copyright (C) 2010 Simon Horman + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +/* + * usage: vrl4 < zImage > out + * dd if=out of=/dev/sdx bs=512 seek=1 # Write the image to sector 1 + * + * Reads a zImage from stdin and writes a vrl4 image to stdout. + * In practice this means writing a padded vrl4 header to stdout followed + * by the zImage. + * + * The padding places the zImage at ALIGN bytes into the output. + * The vrl4 uses ALIGN + START_BASE as the start_address. + * This is where the mask ROM will jump to after verifying the header. + * + * The header sets copy_size to min(sizeof(zImage), MAX_BOOT_PROG_LEN) + ALIGN. + * That is, the mask ROM will load the padded header (ALIGN bytes) + * And then MAX_BOOT_PROG_LEN bytes of the image, or the entire image, + * whichever is smaller. + * + * The zImage is not modified in any way. + */ + +#define _BSD_SOURCE +#include <endian.h> +#include <unistd.h> +#include <stdint.h> +#include <stdio.h> +#include <errno.h> + +struct hdr { + uint32_t magic1; + uint32_t reserved1; + uint32_t magic2; + uint32_t reserved2; + uint16_t copy_size; + uint16_t boot_options; + uint32_t reserved3; + uint32_t start_address; + uint32_t reserved4; + uint32_t reserved5; + char reserved6[308]; +}; + +#define DECLARE_HDR(h) \ + struct hdr (h) = { \ + .magic1 = htole32(0xea000000), \ + .reserved1 = htole32(0x56), \ + .magic2 = htole32(0xe59ff008), \ + .reserved3 = htole16(0x1) } + +/* Align to 512 bytes, the MMCIF sector size */ +#define ALIGN_BITS 9 +#define ALIGN (1 << ALIGN_BITS) + +#define START_BASE 0xe55b0000 + +/* + * With an alignment of 512 the header uses the first sector. + * There is a 128 sector (64kbyte) limit on the data loaded by the mask ROM. + * So there are 127 sectors left for the boot programme. But in practice + * Only a small portion of a zImage is needed, 16 sectors should be more + * than enough. + * + * Note that this sets how much of the zImage is copied by the mask ROM. + * The entire zImage is present after the header and is loaded + * by the code in the boot program (which is the first portion of the zImage). + */ +#define MAX_BOOT_PROG_LEN (16 * 512) + +#define ROUND_UP(x) ((x + ALIGN - 1) & ~(ALIGN - 1)) + +ssize_t do_read(int fd, void *buf, size_t count) +{ + size_t offset = 0; + ssize_t l; + + while (offset < count) { + l = read(fd, buf + offset, count - offset); + if (!l) + break; + if (l < 0) { + if (errno == EAGAIN || errno == EWOULDBLOCK) + continue; + perror("read"); + return -1; + } + offset += l; + } + + return offset; +} + +ssize_t do_write(int fd, const void *buf, size_t count) +{ + size_t offset = 0; + ssize_t l; + + while (offset < count) { + l = write(fd, buf + offset, count - offset); + if (l < 0) { + if (errno == EAGAIN || errno == EWOULDBLOCK) + continue; + perror("write"); + return -1; + } + offset += l; + } + + return offset; +} + +ssize_t write_zero(int fd, size_t len) +{ + size_t i = len; + + while (i--) { + const char x = 0; + if (do_write(fd, &x, 1) < 0) + return -1; + } + + return len; +} + +int main(void) +{ + DECLARE_HDR(hdr); + char boot_program[MAX_BOOT_PROG_LEN]; + size_t aligned_hdr_len, alligned_prog_len; + ssize_t prog_len; + + prog_len = do_read(0, boot_program, sizeof(boot_program)); + if (prog_len <= 0) + return -1; + + aligned_hdr_len = ROUND_UP(sizeof(hdr)); + hdr.start_address = htole32(START_BASE + aligned_hdr_len); + alligned_prog_len = ROUND_UP(prog_len); + hdr.copy_size = htole16(aligned_hdr_len + alligned_prog_len); + + if (do_write(1, &hdr, sizeof(hdr)) < 0) + return -1; + if (write_zero(1, aligned_hdr_len - sizeof(hdr)) < 0) + return -1; + + if (do_write(1, boot_program, prog_len) < 0) + return 1; + + /* Write out the rest of the kernel */ + while (1) { + prog_len = do_read(0, boot_program, sizeof(boot_program)); + if (prog_len < 0) + return 1; + if (prog_len == 0) + break; + if (do_write(1, boot_program, prog_len) < 0) + return 1; + } + + return 0; +} diff --git a/Documentation/arm/SH-Mobile/zboot-rom-mmcif.txt b/Documentation/arm/SH-Mobile/zboot-rom-mmcif.txt new file mode 100644 index 00000000000..efff8ae2713 --- /dev/null +++ b/Documentation/arm/SH-Mobile/zboot-rom-mmcif.txt @@ -0,0 +1,29 @@ +ROM-able zImage boot from MMC +----------------------------- + +An ROM-able zImage compiled with ZBOOT_ROM_MMCIF may be written to MMC and +SuperH Mobile ARM will to boot directly from the MMCIF hardware block. + +This is achieved by the mask ROM loading the first portion of the image into +MERAM and then jumping to it. This portion contains loader code which +copies the entire image to SDRAM and jumps to it. From there the zImage +boot code proceeds as normal, uncompressing the image into its final +location and then jumping to it. + +This code has been tested on an AP4EB board using the developer 1A eMMC +boot mode which is configured using the following jumper settings. +The board used for testing required a patched mask ROM in order for +this mode to function. + + 8 7 6 5 4 3 2 1 + x|x|x|x|x| |x| +S4 -+-+-+-+-+-+-+- + | | | | |x| |x on + +The zImage must be written to the MMC card at sector 1 (512 bytes) in +vrl4 format. A utility vrl4 is supplied to accomplish this. + +e.g. + vrl4 < zImage | dd of=/dev/sdX bs=512 seek=1 + +A dual-voltage MMC 4.0 card was used for testing. diff --git a/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt new file mode 100644 index 00000000000..441959846e1 --- /dev/null +++ b/Documentation/arm/SH-Mobile/zboot-rom-sdhi.txt @@ -0,0 +1,42 @@ +ROM-able zImage boot from eSD +----------------------------- + +An ROM-able zImage compiled with ZBOOT_ROM_SDHI may be written to eSD and +SuperH Mobile ARM will to boot directly from the SDHI hardware block. + +This is achieved by the mask ROM loading the first portion of the image into +MERAM and then jumping to it. This portion contains loader code which +copies the entire image to SDRAM and jumps to it. From there the zImage +boot code proceeds as normal, uncompressing the image into its final +location and then jumping to it. + +This code has been tested on an mackerel board using the developer 1A eSD +boot mode which is configured using the following jumper settings. + + 8 7 6 5 4 3 2 1 + x|x|x|x| |x|x| +S4 -+-+-+-+-+-+-+- + | | | |x| | |x on + +The eSD card needs to be present in SDHI slot 1 (CN7). +As such S1 and S33 also need to be configured as per +the notes in arch/arm/mach-shmobile/board-mackerel.c. + +A partial zImage must be written to physical partition #1 (boot) +of the eSD at sector 0 in vrl4 format. A utility vrl4 is supplied to +accomplish this. + +e.g. + vrl4 < zImage | dd of=/dev/sdX bs=512 count=17 + +A full copy of _the same_ zImage should be written to physical partition #1 +(boot) of the eSD at sector 0. This should _not_ be in vrl4 format. + + vrl4 < zImage | dd of=/dev/sdX bs=512 + +Note: The commands above assume that the physical partition has been +switched. No such facility currently exists in the Linux Kernel. + +Physical partitions are described in the eSD specification. At the time of +writing they are not the same as partitions that are typically configured +using fdisk and visible through /proc/partitions diff --git a/Documentation/arm/SPEAr/overview.txt b/Documentation/arm/SPEAr/overview.txt new file mode 100644 index 00000000000..65610bf52eb --- /dev/null +++ b/Documentation/arm/SPEAr/overview.txt @@ -0,0 +1,63 @@ + SPEAr ARM Linux Overview + ========================== + +Introduction +------------ + + SPEAr (Structured Processor Enhanced Architecture). + weblink : http://www.st.com/spear + + The ST Microelectronics SPEAr range of ARM9/CortexA9 System-on-Chip CPUs are + supported by the 'spear' platform of ARM Linux. Currently SPEAr1310, + SPEAr1340, SPEAr300, SPEAr310, SPEAr320 and SPEAr600 SOCs are supported. + + Hierarchy in SPEAr is as follows: + + SPEAr (Platform) + - SPEAr3XX (3XX SOC series, based on ARM9) + - SPEAr300 (SOC) + - SPEAr300 Evaluation Board + - SPEAr310 (SOC) + - SPEAr310 Evaluation Board + - SPEAr320 (SOC) + - SPEAr320 Evaluation Board + - SPEAr6XX (6XX SOC series, based on ARM9) + - SPEAr600 (SOC) + - SPEAr600 Evaluation Board + - SPEAr13XX (13XX SOC series, based on ARM CORTEXA9) + - SPEAr1310 (SOC) + - SPEAr1310 Evaluation Board + - SPEAr1340 (SOC) + - SPEAr1340 Evaluation Board + + Configuration + ------------- + + A generic configuration is provided for each machine, and can be used as the + default by + make spear13xx_defconfig + make spear3xx_defconfig + make spear6xx_defconfig + + Layout + ------ + + The common files for multiple machine families (SPEAr3xx, SPEAr6xx and + SPEAr13xx) are located in the platform code contained in arch/arm/plat-spear + with headers in plat/. + + Each machine series have a directory with name arch/arm/mach-spear followed by + series name. Like mach-spear3xx, mach-spear6xx and mach-spear13xx. + + Common file for machines of spear3xx family is mach-spear3xx/spear3xx.c, for + spear6xx is mach-spear6xx/spear6xx.c and for spear13xx family is + mach-spear13xx/spear13xx.c. mach-spear* also contain soc/machine specific + files, like spear1310.c, spear1340.c spear300.c, spear310.c, spear320.c and + spear600.c. mach-spear* doesn't contains board specific files as they fully + support Flattened Device Tree. + + + Document Author + --------------- + + Viresh Kumar <viresh.linux@gmail.com>, (c) 2010-2012 ST Microelectronics diff --git a/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt b/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt new file mode 100644 index 00000000000..fa968aa99d6 --- /dev/null +++ b/Documentation/arm/Samsung-S3C24XX/CPUfreq.txt @@ -0,0 +1,75 @@ + S3C24XX CPUfreq support + ======================= + +Introduction +------------ + + The S3C24XX series support a number of power saving systems, such as + the ability to change the core, memory and peripheral operating + frequencies. The core control is exported via the CPUFreq driver + which has a number of different manual or automatic controls over the + rate the core is running at. + + There are two forms of the driver depending on the specific CPU and + how the clocks are arranged. The first implementation used as single + PLL to feed the ARM, memory and peripherals via a series of dividers + and muxes and this is the implementation that is documented here. A + newer version where there is a separate PLL and clock divider for the + ARM core is available as a separate driver. + + +Layout +------ + + The code core manages the CPU specific drivers, any data that they + need to register and the interface to the generic drivers/cpufreq + system. Each CPU registers a driver to control the PLL, clock dividers + and anything else associated with it. Any board that wants to use this + framework needs to supply at least basic details of what is required. + + The core registers with drivers/cpufreq at init time if all the data + necessary has been supplied. + + +CPU support +----------- + + The support for each CPU depends on the facilities provided by the + SoC and the driver as each device has different PLL and clock chains + associated with it. + + +Slow Mode +--------- + + The SLOW mode where the PLL is turned off altogether and the + system is fed by the external crystal input is currently not + supported. + + +sysfs +----- + + The core code exports extra information via sysfs in the directory + devices/system/cpu/cpu0/arch-freq. + + +Board Support +------------- + + Each board that wants to use the cpufreq code must register some basic + information with the core driver to provide information about what the + board requires and any restrictions being placed on it. + + The board needs to supply information about whether it needs the IO bank + timings changing, any maximum frequency limits and information about the + SDRAM refresh rate. + + + + +Document Author +--------------- + +Ben Dooks, Copyright 2009 Simtec Electronics +Licensed under GPLv2 diff --git a/Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt b/Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt index 26422f0f908..b87292e05f2 100644 --- a/Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt +++ b/Documentation/arm/Samsung-S3C24XX/EB2410ITX.txt @@ -55,4 +55,4 @@ Maintainers This board is maintained by Simtec Electronics. -(c) 2004 Ben Dooks, Simtec Electronics +Copyright 2004 Ben Dooks, Simtec Electronics diff --git a/Documentation/arm/Samsung-S3C24XX/GPIO.txt b/Documentation/arm/Samsung-S3C24XX/GPIO.txt index 8caea8c237e..0ebd7e2244d 100644 --- a/Documentation/arm/Samsung-S3C24XX/GPIO.txt +++ b/Documentation/arm/Samsung-S3C24XX/GPIO.txt @@ -1,4 +1,4 @@ - S3C2410 GPIO Control + S3C24XX GPIO Control ==================== Introduction @@ -12,33 +12,96 @@ Introduction of the s3c2410 GPIO system, please read the Samsung provided data-sheet/users manual to find out the complete list. + See Documentation/arm/Samsung/GPIO.txt for the core implementation. -Headers + +GPIOLIB ------- - See include/asm-arm/arch-s3c2410/regs-gpio.h for the list - of GPIO pins, and the configuration values for them. This - is included by using #include <asm/arch/regs-gpio.h> + With the event of the GPIOLIB in drivers/gpio, support for some + of the GPIO functions such as reading and writing a pin will + be removed in favour of this common access method. + + Once all the extant drivers have been converted, the functions + listed below will be removed (they may be marked as __deprecated + in the near future). + + The following functions now either have a s3c_ specific variant + or are merged into gpiolib. See the definitions in + arch/arm/plat-samsung/include/plat/gpio-cfg.h: + + s3c2410_gpio_setpin() gpio_set_value() or gpio_direction_output() + s3c2410_gpio_getpin() gpio_get_value() or gpio_direction_input() + s3c2410_gpio_getirq() gpio_to_irq() + s3c2410_gpio_cfgpin() s3c_gpio_cfgpin() + s3c2410_gpio_getcfg() s3c_gpio_getcfg() + s3c2410_gpio_pullup() s3c_gpio_setpull() + + +GPIOLIB conversion +------------------ + +If you need to convert your board or driver to use gpiolib from the phased +out s3c2410 API, then here are some notes on the process. + +1) If your board is exclusively using an GPIO, say to control peripheral + power, then it will require to claim the gpio with gpio_request() before + it can use it. + + It is recommended to check the return value, with at least WARN_ON() + during initialisation. + +2) The s3c2410_gpio_cfgpin() can be directly replaced with s3c_gpio_cfgpin() + as they have the same arguments, and can either take the pin specific + values, or the more generic special-function-number arguments. + +3) s3c2410_gpio_pullup() changes have the problem that whilst the + s3c2410_gpio_pullup(x, 1) can be easily translated to the + s3c_gpio_setpull(x, S3C_GPIO_PULL_NONE), the s3c2410_gpio_pullup(x, 0) + are not so easy. + + The s3c2410_gpio_pullup(x, 0) case enables the pull-up (or in the case + of some of the devices, a pull-down) and as such the new API distinguishes + between the UP and DOWN case. There is currently no 'just turn on' setting + which may be required if this becomes a problem. + +4) s3c2410_gpio_setpin() can be replaced by gpio_set_value(), the old call + does not implicitly configure the relevant gpio to output. The gpio + direction should be changed before using gpio_set_value(). - The GPIO management functions are defined in the hardware - header include/asm-arm/arch-s3c2410/hardware.h which can be - included by #include <asm/arch/hardware.h> +5) s3c2410_gpio_getpin() is replaceable by gpio_get_value() if the pin + has been set to input. It is currently unknown what the behaviour is + when using gpio_get_value() on an output pin (s3c2410_gpio_getpin + would return the value the pin is supposed to be outputting). - A useful amount of documentation can be found in the hardware - header on how the GPIO functions (and others) work. +6) s3c2410_gpio_getirq() should be directly replaceable with the + gpio_to_irq() call. - Whilst a number of these functions do make some checks on what - is passed to them, for speed of use, they may not always ensure - that the user supplied data to them is correct. +The s3c2410_gpio and gpio_ calls have always operated on the same gpio +numberspace, so there is no problem with converting the gpio numbering +between the calls. + + +Headers +------- + + See arch/arm/mach-s3c24xx/include/mach/regs-gpio.h for the list + of GPIO pins, and the configuration values for them. This + is included by using #include <mach/regs-gpio.h> PIN Numbers ----------- Each pin has an unique number associated with it in regs-gpio.h, - eg S3C2410_GPA0 or S3C2410_GPF1. These defines are used to tell + e.g. S3C2410_GPA(0) or S3C2410_GPF(1). These defines are used to tell the GPIO functions which pin is to be used. + With the conversion to gpiolib, there is no longer a direct conversion + from gpio pin number to register base address as in earlier kernels. This + is due to the number space required for newer SoCs where the later + GPIOs are not contiguous. + Configuring a pin ----------------- @@ -46,26 +109,27 @@ Configuring a pin The following function allows the configuration of a given pin to be changed. - void s3c2410_gpio_cfgpin(unsigned int pin, unsigned int function); + void s3c_gpio_cfgpin(unsigned int pin, unsigned int function); - Eg: + e.g.: - s3c2410_gpio_cfgpin(S3C2410_GPA0, S3C2410_GPA0_ADDR0); - s3c2410_gpio_cfgpin(S3C2410_GPE8, S3C2410_GPE8_SDDAT1); + s3c_gpio_cfgpin(S3C2410_GPA(0), S3C_GPIO_SFN(1)); + s3c_gpio_cfgpin(S3C2410_GPE(8), S3C_GPIO_SFN(2)); - which would turn GPA0 into the lowest Address line A0, and set - GPE8 to be connected to the SDIO/MMC controller's SDDAT1 line. + which would turn GPA(0) into the lowest Address line A0, and set + GPE(8) to be connected to the SDIO/MMC controller's SDDAT1 line. Reading the current configuration --------------------------------- - The current configuration of a pin can be read by using: + The current configuration of a pin can be read by using standard + gpiolib function: - s3c2410_gpio_getcfg(unsigned int pin); + s3c_gpio_getcfg(unsigned int pin); The return value will be from the same set of values which can be - passed to s3c2410_gpio_cfgpin(). + passed to s3c_gpio_cfgpin(). Configuring a pull-up resistor @@ -75,48 +139,33 @@ Configuring a pull-up resistor pull-up resistors enabled. This can be configured by the following function: - void s3c2410_gpio_pullup(unsigned int pin, unsigned int to); - - Where the to value is zero to set the pull-up off, and 1 to enable - the specified pull-up. Any other values are currently undefined. + void s3c_gpio_setpull(unsigned int pin, unsigned int to); + Where the to value is S3C_GPIO_PULL_NONE to set the pull-up off, + and S3C_GPIO_PULL_UP to enable the specified pull-up. Any other + values are currently undefined. -Getting the state of a PIN --------------------------- - The state of a pin can be read by using the function: +Getting and setting the state of a PIN +-------------------------------------- - unsigned int s3c2410_gpio_getpin(unsigned int pin); - - This will return either zero or non-zero. Do not count on this - function returning 1 if the pin is set. - - -Setting the state of a PIN --------------------------- - - The value an pin is outputing can be modified by using the following: - - void s3c2410_gpio_setpin(unsigned int pin, unsigned int to); - - Which sets the given pin to the value. Use 0 to write 0, and 1 to - set the output to 1. + These calls are now implemented by the relevant gpiolib calls, convert + your board or driver to use gpiolib. Getting the IRQ number associated with a PIN -------------------------------------------- - The following function can map the given pin number to an IRQ + A standard gpiolib function can map the given pin number to an IRQ number to pass to the IRQ system. - int s3c2410_gpio_getirq(unsigned int pin); + int gpio_to_irq(unsigned int pin); Note, not all pins have an IRQ. -Authour +Author ------- - Ben Dooks, 03 October 2004 -(c) 2004 Ben Dooks, Simtec Electronics +Copyright 2004 Ben Dooks, Simtec Electronics diff --git a/Documentation/arm/Samsung-S3C24XX/H1940.txt b/Documentation/arm/Samsung-S3C24XX/H1940.txt index f4a7b22c866..b738859b1fc 100644 --- a/Documentation/arm/Samsung-S3C24XX/H1940.txt +++ b/Documentation/arm/Samsung-S3C24XX/H1940.txt @@ -37,4 +37,4 @@ Maintainers Thanks to the many others who have also provided support. -(c) 2005 Ben Dooks
\ No newline at end of file +(c) 2005 Ben Dooks diff --git a/Documentation/arm/Samsung-S3C24XX/NAND.txt b/Documentation/arm/Samsung-S3C24XX/NAND.txt new file mode 100644 index 00000000000..bc478a3409b --- /dev/null +++ b/Documentation/arm/Samsung-S3C24XX/NAND.txt @@ -0,0 +1,30 @@ + S3C24XX NAND Support + ==================== + +Introduction +------------ + +Small Page NAND +--------------- + +The driver uses a 512 byte (1 page) ECC code for this setup. The +ECC code is not directly compatible with the default kernel ECC +code, so the driver enforces its own OOB layout and ECC parameters + +Large Page NAND +--------------- + +The driver is capable of handling NAND flash with a 2KiB page +size, with support for hardware ECC generation and correction. + +Unlike the 512byte page mode, the driver generates ECC data for +each 256 byte block in an 2KiB page. This means that more than +one error in a page can be rectified. It also means that the +OOB layout remains the default kernel layout for these flashes. + + +Document Author +--------------- + +Ben Dooks, Copyright 2007 Simtec Electronics + diff --git a/Documentation/arm/Samsung-S3C24XX/Overview.txt b/Documentation/arm/Samsung-S3C24XX/Overview.txt index c31b76fa66c..359587b2367 100644 --- a/Documentation/arm/Samsung-S3C24XX/Overview.txt +++ b/Documentation/arm/Samsung-S3C24XX/Overview.txt @@ -8,9 +8,19 @@ Introduction The Samsung S3C24XX range of ARM9 System-on-Chip CPUs are supported by the 's3c2410' architecture of ARM Linux. Currently the S3C2410, - S3C2412, S3C2413, S3C2440 and S3C2442 devices are supported. + S3C2412, S3C2413, S3C2416, S3C2440, S3C2442, S3C2443 and S3C2450 devices + are supported. + + Support for the S3C2400 and S3C24A0 series was never completed and the + corresponding code has been removed after a while. If someone wishes to + revive this effort, partial support can be retrieved from earlier Linux + versions. + + The S3C2416 and S3C2450 devices are very similar and S3C2450 support is + included under the arch/arm/mach-s3c2416 directory. Note, whilst core + support for these SoCs is in, work on some of the extra peripherals + and extra interrupts is still ongoing. - Support for the S3C2400 series is in progress. Configuration ------------- @@ -36,7 +46,23 @@ Layout in arch/arm/mach-s3c2410 and S3C2440 in arch/arm/mach-s3c2440 Register, kernel and platform data definitions are held in the - include/asm-arm/arch-s3c2410 directory. + arch/arm/mach-s3c2410 directory./include/mach + +arch/arm/plat-s3c24xx: + + Files in here are either common to all the s3c24xx family, + or are common to only some of them with names to indicate this + status. The files that are not common to all are generally named + with the initial cpu they support in the series to ensure a short + name without any possibility of confusion with newer devices. + + As an example, initially s3c244x would cover s3c2440 and s3c2442, but + with the s3c2443 which does not share many of the same drivers in + this directory, the name becomes invalid. We stick to s3c2440-<x> + to indicate a driver that is s3c2440 and s3c2442 compatible. + + This does mean that to find the status of any given SoC, a number + of directories may need to be searched. Machines @@ -156,6 +182,19 @@ NAND controller. If there are any problems the latest linux-mtd code can be found from http://www.linux-mtd.infradead.org/ + For more information see Documentation/arm/Samsung-S3C24XX/NAND.txt + + +SD/MMC +------ + + The SD/MMC hardware pre S3C2443 is supported in the current + kernel, the driver is drivers/mmc/host/s3cmci.c and supports + 1 and 4 bit SD or MMC cards. + + The SDIO behaviour of this driver has not been fully tested. There is no + current support for hardware SDIO interrupts. + Serial ------ @@ -176,6 +215,16 @@ GPIO The core contains support for manipulating the GPIO, see the documentation in GPIO.txt in the same directory as this file. + Newer kernels carry GPIOLIB, and support is being moved towards + this with some of the older support in line to be removed. + + As of v2.6.34, the move towards using gpiolib support is almost + complete, and very little of the old calls are left. + + See Documentation/arm/Samsung-S3C24XX/GPIO.txt for the S3C24XX specific + support and Documentation/arm/Samsung/GPIO.txt for the core Samsung + implementation. + Clock Management ---------------- @@ -266,4 +315,4 @@ Port Contributors Document Author --------------- -Ben Dooks, (c) 2004-2005,2006 Simtec Electronics +Ben Dooks, Copyright 2004-2006 Simtec Electronics diff --git a/Documentation/arm/Samsung-S3C24XX/S3C2412.txt b/Documentation/arm/Samsung-S3C24XX/S3C2412.txt index 295d971a15e..f057876b920 100644 --- a/Documentation/arm/Samsung-S3C24XX/S3C2412.txt +++ b/Documentation/arm/Samsung-S3C24XX/S3C2412.txt @@ -117,4 +117,4 @@ ATA Document Author --------------- -Ben Dooks, (c) 2006 Simtec Electronics +Ben Dooks, Copyright 2006 Simtec Electronics diff --git a/Documentation/arm/Samsung-S3C24XX/S3C2413.txt b/Documentation/arm/Samsung-S3C24XX/S3C2413.txt index ab2a88858f1..909bdc7dd7b 100644 --- a/Documentation/arm/Samsung-S3C24XX/S3C2413.txt +++ b/Documentation/arm/Samsung-S3C24XX/S3C2413.txt @@ -18,4 +18,4 @@ Camera Interface Document Author --------------- -Ben Dooks, (c) 2006 Simtec Electronics +Ben Dooks, Copyright 2006 Simtec Electronics diff --git a/Documentation/arm/Samsung-S3C24XX/SMDK2440.txt b/Documentation/arm/Samsung-S3C24XX/SMDK2440.txt index 32e1eae6a25..429390bd468 100644 --- a/Documentation/arm/Samsung-S3C24XX/SMDK2440.txt +++ b/Documentation/arm/Samsung-S3C24XX/SMDK2440.txt @@ -53,4 +53,4 @@ Maintainers and to Simtec Electronics for allowing me time to work on this. -(c) 2004 Ben Dooks
\ No newline at end of file +(c) 2004 Ben Dooks diff --git a/Documentation/arm/Samsung-S3C24XX/Suspend.txt b/Documentation/arm/Samsung-S3C24XX/Suspend.txt index 0dab6e32c13..1ca63b3e563 100644 --- a/Documentation/arm/Samsung-S3C24XX/Suspend.txt +++ b/Documentation/arm/Samsung-S3C24XX/Suspend.txt @@ -40,13 +40,13 @@ Resuming Machine Support --------------- - The machine specific functions must call the s3c2410_pm_init() function + The machine specific functions must call the s3c_pm_init() function to say that its bootloader is capable of resuming. This can be as simple as adding the following to the machine's definition: - INITMACHINE(s3c2410_pm_init) + INITMACHINE(s3c_pm_init) - A board can do its own setup before calling s3c2410_pm_init, if it + A board can do its own setup before calling s3c_pm_init, if it needs to setup anything else for power management support. There is currently no support for over-riding the default method of @@ -74,7 +74,7 @@ statuc void __init machine_init(void) enable_irq_wake(IRQ_EINT0); - s3c2410_pm_init(); + s3c_pm_init(); } @@ -116,7 +116,7 @@ Configuration Allows the entire memory to be checksummed before and after the suspend to see if there has been any corruption of the contents. - Note, the time to calculate the CRC is dependant on the CPU speed + Note, the time to calculate the CRC is dependent on the CPU speed and the size of memory. For an 64Mbyte RAM area on an 200MHz S3C2410, this can take approximately 4 seconds to complete. @@ -133,5 +133,5 @@ Configuration Document Author --------------- -Ben Dooks, (c) 2004 Simtec Electronics +Ben Dooks, Copyright 2004 Simtec Electronics diff --git a/Documentation/arm/Samsung-S3C24XX/USB-Host.txt b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt index b93b68e2b14..f82b1faefad 100644 --- a/Documentation/arm/Samsung-S3C24XX/USB-Host.txt +++ b/Documentation/arm/Samsung-S3C24XX/USB-Host.txt @@ -49,7 +49,7 @@ Board Support Platform Data ------------- - See linux/include/asm-arm/arch-s3c2410/usb-control.h for the + See arch/arm/mach-s3c2410/include/mach/usb-control.h for the descriptions of the platform device data. An implementation can be found in linux/arch/arm/mach-s3c2410/usb-simtec.c . @@ -90,4 +90,4 @@ Platform Data Document Author --------------- -Ben Dooks, (c) 2005 Simtec Electronics +Ben Dooks, Copyright 2005 Simtec Electronics diff --git a/Documentation/arm/Samsung/GPIO.txt b/Documentation/arm/Samsung/GPIO.txt new file mode 100644 index 00000000000..795adfd8808 --- /dev/null +++ b/Documentation/arm/Samsung/GPIO.txt @@ -0,0 +1,40 @@ + Samsung GPIO implementation + =========================== + +Introduction +------------ + +This outlines the Samsung GPIO implementation and the architecture +specific calls provided alongside the drivers/gpio core. + + +S3C24XX (Legacy) +---------------- + +See Documentation/arm/Samsung-S3C24XX/GPIO.txt for more information +about these devices. Their implementation has been brought into line +with the core samsung implementation described in this document. + + +GPIOLIB integration +------------------- + +The gpio implementation uses gpiolib as much as possible, only providing +specific calls for the items that require Samsung specific handling, such +as pin special-function or pull resistor control. + +GPIO numbering is synchronised between the Samsung and gpiolib system. + + +PIN configuration +----------------- + +Pin configuration is specific to the Samsung architecture, with each SoC +registering the necessary information for the core gpio configuration +implementation to configure pins as necessary. + +The s3c_gpio_cfgpin() and s3c_gpio_setpull() provide the means for a +driver or machine to change gpio configuration. + +See arch/arm/plat-samsung/include/plat/gpio-cfg.h for more information +on these functions. diff --git a/Documentation/arm/Samsung/Overview.txt b/Documentation/arm/Samsung/Overview.txt new file mode 100644 index 00000000000..658abb258ce --- /dev/null +++ b/Documentation/arm/Samsung/Overview.txt @@ -0,0 +1,97 @@ + Samsung ARM Linux Overview + ========================== + +Introduction +------------ + + The Samsung range of ARM SoCs spans many similar devices, from the initial + ARM9 through to the newest ARM cores. This document shows an overview of + the current kernel support, how to use it and where to find the code + that supports this. + + The currently supported SoCs are: + + - S3C24XX: See Documentation/arm/Samsung-S3C24XX/Overview.txt for full list + - S3C64XX: S3C6400 and S3C6410 + - S5P6440 + - S5PC100 + - S5PC110 / S5PV210 + + +S3C24XX Systems +--------------- + + There is still documentation in Documnetation/arm/Samsung-S3C24XX/ which + deals with the architecture and drivers specific to these devices. + + See Documentation/arm/Samsung-S3C24XX/Overview.txt for more information + on the implementation details and specific support. + + +Configuration +------------- + + A number of configurations are supplied, as there is no current way of + unifying all the SoCs into one kernel. + + s5p6440_defconfig - S5P6440 specific default configuration + s5pc100_defconfig - S5PC100 specific default configuration + s5pc110_defconfig - S5PC110 specific default configuration + s5pv210_defconfig - S5PV210 specific default configuration + + +Layout +------ + + The directory layout is currently being restructured, and consists of + several platform directories and then the machine specific directories + of the CPUs being built for. + + plat-samsung provides the base for all the implementations, and is the + last in the line of include directories that are processed for the build + specific information. It contains the base clock, GPIO and device definitions + to get the system running. + + plat-s3c24xx is for s3c24xx specific builds, see the S3C24XX docs. + + plat-s5p is for s5p specific builds, and contains common support for the + S5P specific systems. Not all S5Ps use all the features in this directory + due to differences in the hardware. + + +Layout changes +-------------- + + The old plat-s3c and plat-s5pc1xx directories have been removed, with + support moved to either plat-samsung or plat-s5p as necessary. These moves + where to simplify the include and dependency issues involved with having + so many different platform directories. + + It was decided to remove plat-s5pc1xx as some of the support was already + in plat-s5p or plat-samsung, with the S5PC110 support added with S5PV210 + the only user was the S5PC100. The S5PC100 specific items where moved to + arch/arm/mach-s5pc100. + + + + +Port Contributors +----------------- + + Ben Dooks (BJD) + Vincent Sanders + Herbert Potzl + Arnaud Patard (RTP) + Roc Wu + Klaus Fetscher + Dimitry Andric + Shannon Holland + Guillaume Gourat (NexVision) + Christer Weinigel (wingel) (Acer N30) + Lucas Correia Villa Real (S3C2400 port) + + +Document Author +--------------- + +Copyright 2009-2010 Ben Dooks <ben-linux@fluff.org> diff --git a/Documentation/arm/Samsung/clksrc-change-registers.awk b/Documentation/arm/Samsung/clksrc-change-registers.awk new file mode 100755 index 00000000000..0c50220851f --- /dev/null +++ b/Documentation/arm/Samsung/clksrc-change-registers.awk @@ -0,0 +1,167 @@ +#!/usr/bin/awk -f +# +# Copyright 2010 Ben Dooks <ben-linux@fluff.org> +# +# Released under GPLv2 + +# example usage +# ./clksrc-change-registers.awk arch/arm/plat-s5pc1xx/include/plat/regs-clock.h < src > dst + +function extract_value(s) +{ + eqat = index(s, "=") + comat = index(s, ",") + return substr(s, eqat+2, (comat-eqat)-2) +} + +function remove_brackets(b) +{ + return substr(b, 2, length(b)-2) +} + +function splitdefine(l, p) +{ + r = split(l, tp) + + p[0] = tp[2] + p[1] = remove_brackets(tp[3]) +} + +function find_length(f) +{ + if (0) + printf "find_length " f "\n" > "/dev/stderr" + + if (f ~ /0x1/) + return 1 + else if (f ~ /0x3/) + return 2 + else if (f ~ /0x7/) + return 3 + else if (f ~ /0xf/) + return 4 + + printf "unknown legnth " f "\n" > "/dev/stderr" + exit +} + +function find_shift(s) +{ + id = index(s, "<") + if (id <= 0) { + printf "cannot find shift " s "\n" > "/dev/stderr" + exit + } + + return substr(s, id+2) +} + + +BEGIN { + if (ARGC < 2) { + print "too few arguments" > "/dev/stderr" + exit + } + +# read the header file and find the mask values that we will need +# to replace and create an associative array of values + + while (getline line < ARGV[1] > 0) { + if (line ~ /\#define.*_MASK/ && + !(line ~ /S5PC100_EPLL_MASK/) && + !(line ~ /USB_SIG_MASK/)) { + splitdefine(line, fields) + name = fields[0] + if (0) + printf "MASK " line "\n" > "/dev/stderr" + dmask[name,0] = find_length(fields[1]) + dmask[name,1] = find_shift(fields[1]) + if (0) + printf "=> '" name "' LENGTH=" dmask[name,0] " SHIFT=" dmask[name,1] "\n" > "/dev/stderr" + } else { + } + } + + delete ARGV[1] +} + +/clksrc_clk.*=.*{/ { + shift="" + mask="" + divshift="" + reg_div="" + reg_src="" + indent=1 + + print $0 + + for(; indent >= 1;) { + if ((getline line) <= 0) { + printf "unexpected end of file" > "/dev/stderr" + exit 1; + } + + if (line ~ /\.shift/) { + shift = extract_value(line) + } else if (line ~ /\.mask/) { + mask = extract_value(line) + } else if (line ~ /\.reg_divider/) { + reg_div = extract_value(line) + } else if (line ~ /\.reg_source/) { + reg_src = extract_value(line) + } else if (line ~ /\.divider_shift/) { + divshift = extract_value(line) + } else if (line ~ /{/) { + indent++ + print line + } else if (line ~ /}/) { + indent-- + + if (indent == 0) { + if (0) { + printf "shift '" shift "' ='" dmask[shift,0] "'\n" > "/dev/stderr" + printf "mask '" mask "'\n" > "/dev/stderr" + printf "dshft '" divshift "'\n" > "/dev/stderr" + printf "rdiv '" reg_div "'\n" > "/dev/stderr" + printf "rsrc '" reg_src "'\n" > "/dev/stderr" + } + + generated = mask + sub(reg_src, reg_div, generated) + + if (0) { + printf "/* rsrc " reg_src " */\n" + printf "/* rdiv " reg_div " */\n" + printf "/* shift " shift " */\n" + printf "/* mask " mask " */\n" + printf "/* generated " generated " */\n" + } + + if (reg_div != "") { + printf "\t.reg_div = { " + printf ".reg = " reg_div ", " + printf ".shift = " dmask[generated,1] ", " + printf ".size = " dmask[generated,0] ", " + printf "},\n" + } + + printf "\t.reg_src = { " + printf ".reg = " reg_src ", " + printf ".shift = " dmask[mask,1] ", " + printf ".size = " dmask[mask,0] ", " + + printf "},\n" + + } + + print line + } else { + print line + } + + if (0) + printf indent ":" line "\n" > "/dev/stderr" + } +} + +// && ! /clksrc_clk.*=.*{/ { print $0 } diff --git a/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen b/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen deleted file mode 100644 index 1e6a23fdf2f..00000000000 --- a/Documentation/arm/Sharp-LH/ADC-LH7-Touchscreen +++ /dev/null @@ -1,61 +0,0 @@ -README on the ADC/Touchscreen Controller -======================================== - -The LH79524 and LH7A404 include a built-in Analog to Digital -controller (ADC) that is used to process input from a touchscreen. -The driver only implements a four-wire touch panel protocol. - -The touchscreen driver is maintenance free except for the pen-down or -touch threshold. Some resistive displays and board combinations may -require tuning of this threshold. The driver exposes some of it's -internal state in the sys filesystem. If the kernel is configured -with it, CONFIG_SYSFS, and sysfs is mounted at /sys, there will be a -directory - - /sys/devices/platform/adc-lh7.0 - -containing these files. - - -r--r--r-- 1 root root 4096 Jan 1 00:00 samples - -rw-r--r-- 1 root root 4096 Jan 1 00:00 threshold - -r--r--r-- 1 root root 4096 Jan 1 00:00 threshold_range - -The threshold is the current touch threshold. It defaults to 750 on -most targets. - - # cat threshold - 750 - -The threshold_range contains the range of valid values for the -threshold. Values outside of this range will be silently ignored. - - # cat threshold_range - 0 1023 - -To change the threshold, write a value to the threshold file. - - # echo 500 > threshold - # cat threshold - 500 - -The samples file contains the most recently sampled values from the -ADC. There are 12. Below are typical of the last sampled values when -the pen has been released. The first two and last two samples are for -detecting whether or not the pen is down. The third through sixth are -X coordinate samples. The seventh through tenth are Y coordinate -samples. - - # cat samples - 1023 1023 0 0 0 0 530 529 530 529 1023 1023 - -To determine a reasonable threshold, press on the touch panel with an -appropriate stylus and read the values from samples. - - # cat samples - 1023 676 92 103 101 102 855 919 922 922 1023 679 - -The first and eleventh samples are discarded. Thus, the important -values are the second and twelfth which are used to determine if the -pen is down. When both are below the threshold, the driver registers -that the pen is down. When either is above the threshold, it -registers then pen is up. diff --git a/Documentation/arm/Sharp-LH/CompactFlash b/Documentation/arm/Sharp-LH/CompactFlash deleted file mode 100644 index 8616d877df9..00000000000 --- a/Documentation/arm/Sharp-LH/CompactFlash +++ /dev/null @@ -1,32 +0,0 @@ -README on the Compact Flash for Card Engines -============================================ - -There are three challenges in supporting the CF interface of the Card -Engines. First, every IO operation must be followed with IO to -another memory region. Second, the slot is wired for one-to-one -address mapping *and* it is wired for 16 bit access only. Second, the -interrupt request line from the CF device isn't wired. - -The IOBARRIER issue is covered in README.IOBARRIER. This isn't an -onerous problem. Enough said here. - -The addressing issue is solved in the -arch/arm/mach-lh7a40x/ide-lpd7a40x.c file with some awkward -work-arounds. We implement a special SELECT_DRIVE routine that is -called before the IDE driver performs its own SELECT_DRIVE. Our code -recognizes that the SELECT register cannot be modified without also -writing a command. It send an IDLE_IMMEDIATE command on selecting a -drive. The function also prevents drive select to the slave drive -since there can be only one. The awkward part is that the IDE driver, -even though we have a select procedure, also attempts to change the -drive by writing directly the SELECT register. This attempt is -explicitly blocked by the OUTB function--not pretty, but effective. - -The lack of interrupts is a more serious problem. Even though the CF -card is fast when compared to a normal IDE device, we don't know that -the CF is really flash. A user could use one of the very small hard -drives being shipped with a CF interface. The IDE code includes a -check for interfaces that lack an IRQ. In these cases, submitting a -command to the IDE controller is followed by a call to poll for -completion. If the device isn't immediately ready, it schedules a -timer to poll again later. diff --git a/Documentation/arm/Sharp-LH/IOBarrier b/Documentation/arm/Sharp-LH/IOBarrier deleted file mode 100644 index 2e953e228f4..00000000000 --- a/Documentation/arm/Sharp-LH/IOBarrier +++ /dev/null @@ -1,45 +0,0 @@ -README on the IOBARRIER for CardEngine IO -========================================= - -Due to an unfortunate oversight when the Card Engines were designed, -the signals that control access to some peripherals, most notably the -SMC91C9111 ethernet controller, are not properly handled. - -The symptom is that some back to back IO with the peripheral returns -unreliable data. With the SMC chip, you'll see errors about the bank -register being 'screwed'. - -The cause is that the AEN signal to the SMC chip does not transition -for every memory access. It is driven through the CPLD from the CS7 -line of the CPU's static memory controller which is optimized to -eliminate unnecessary transitions. Yet, the SMC requires a transition -for every write access. The Sharp website has more information about -the effect this power-conserving feature has on peripheral -interfacing. - -The solution is to follow every write access to the SMC chip with an -access to another memory region that will force the CPU to release the -chip select line. It is important to guarantee that this access -forces the CPU off-chip. We map a page of SDRAM as if it were an -uncacheable IO device and read from it after every SMC IO write -operation. - - SMC IO - BARRIER IO - -Only this sequence is important. It does not matter that there is no -BARRIER IO before the access to the SMC chip because the AEN latch -only needs occurs after the SMC IO write cycle. The routines that -implement this work-around make an additional concession which is to -disable interrupts during the IO sequence. Other hardware devices -(the LogicPD CPLD) have registers in the same physical memory -region as the SMC chip. An interrupt might allow an access to one of -those registers while SMC IO is being performed. - -You might be tempted to think that we have to access another device -attached to the static memory controller, but the empirical evidence -indicates that this is not so. Mapping 0x00000000 (flash) and -0xc0000000 (SDRAM) appear to have the same effect. Using SDRAM seems -to be faster. Choosing to access an undecoded memory region is not -desirable as there is no way to know how that chip select will be used -in the future. diff --git a/Documentation/arm/Sharp-LH/KEV7A400 b/Documentation/arm/Sharp-LH/KEV7A400 deleted file mode 100644 index be32b14cd53..00000000000 --- a/Documentation/arm/Sharp-LH/KEV7A400 +++ /dev/null @@ -1,8 +0,0 @@ -README on Implementing Linux for Sharp's KEV7a400 -================================================= - -This product has been discontinued by Sharp. For the time being, the -partially implemented code remains in the kernel. At some point in -the future, either the code will be finished or it will be removed -completely. This depends primarily on how many of the development -boards are in the field. diff --git a/Documentation/arm/Sharp-LH/LCDPanels b/Documentation/arm/Sharp-LH/LCDPanels deleted file mode 100644 index fb1b21c2f2f..00000000000 --- a/Documentation/arm/Sharp-LH/LCDPanels +++ /dev/null @@ -1,59 +0,0 @@ -README on the LCD Panels -======================== - -Configuration options for several LCD panels, available from Logic PD, -are included in the kernel source. This README will help you -understand the configuration data and give you some guidance for -adding support for other panels if you wish. - - -lcd-panels.h ------------- - -There is no way, at present, to detect which panel is attached to the -system at runtime. Thus the kernel configuration is static. The file -arch/arm/mach-ld7a40x/lcd-panels.h (or similar) defines all of the -panel specific parameters. - -It should be possible for this data to be shared among several device -families. The current layout may be insufficiently general, but it is -amenable to improvement. - - -PIXEL_CLOCK ------------ - -The panel data sheets will give a range of acceptable pixel clocks. -The fundamental LCDCLK input frequency is divided down by a PCD -constant in field '.tim2'. It may happen that it is impossible to set -the pixel clock within this range. A clock which is too slow will -tend to flicker. For the highest quality image, set the clock as high -as possible. - - -MARGINS -------- - -These values may be difficult to glean from the panel data sheet. In -the case of the Sharp panels, the upper margin is explicitly called -out as a specific number of lines from the top of the frame. The -other values may not matter as much as the panels tend to -automatically center the image. - - -Sync Sense ----------- - -The sense of the hsync and vsync pulses may be called out in the data -sheet. On one panel, the sense of these pulses determine the height -of the visible region on the panel. Most of the Sharp panels use -negative sense sync pulses set by the TIM2_IHS and TIM2_IVS bits in -'.tim2'. - - -Pel Layout ----------- - -The Sharp color TFT panels are all configured for 16 bit direct color -modes. The amba-lcd driver sets the pel mode to 565 for 5 bits of -each red and blue and 6 bits of green. diff --git a/Documentation/arm/Sharp-LH/LPD7A400 b/Documentation/arm/Sharp-LH/LPD7A400 deleted file mode 100644 index 3275b453bfd..00000000000 --- a/Documentation/arm/Sharp-LH/LPD7A400 +++ /dev/null @@ -1,15 +0,0 @@ -README on Implementing Linux for the Logic PD LPD7A400-10 -========================================================= - -- CPLD memory mapping - - The board designers chose to use high address lines for controlling - access to the CPLD registers. It turns out to be a big waste - because we're using an MMU and must map IO space into virtual - memory. The result is that we have to make a mapping for every - register. - -- Serial Console - - It may be OK not to use the serial console option if the user passes - the console device name to the kernel. This deserves some exploration. diff --git a/Documentation/arm/Sharp-LH/LPD7A40X b/Documentation/arm/Sharp-LH/LPD7A40X deleted file mode 100644 index 8c29a27e208..00000000000 --- a/Documentation/arm/Sharp-LH/LPD7A40X +++ /dev/null @@ -1,16 +0,0 @@ -README on Implementing Linux for the Logic PD LPD7A40X-10 -========================================================= - -- CPLD memory mapping - - The board designers chose to use high address lines for controlling - access to the CPLD registers. It turns out to be a big waste - because we're using an MMU and must map IO space into virtual - memory. The result is that we have to make a mapping for every - register. - -- Serial Console - - It may be OK not to use the serial console option if the user passes - the console device name to the kernel. This deserves some exploration. - diff --git a/Documentation/arm/Sharp-LH/SDRAM b/Documentation/arm/Sharp-LH/SDRAM deleted file mode 100644 index 93ddc23c2fa..00000000000 --- a/Documentation/arm/Sharp-LH/SDRAM +++ /dev/null @@ -1,51 +0,0 @@ -README on the SDRAM Controller for the LH7a40X -============================================== - -The standard configuration for the SDRAM controller generates a sparse -memory array. The precise layout is determined by the SDRAM chips. A -default kernel configuration assembles the discontiguous memory -regions into separate memory nodes via the NUMA (Non-Uniform Memory -Architecture) facilities. In this default configuration, the kernel -is forgiving about the precise layout. As long as it is given an -accurate picture of available memory by the bootloader the kernel will -execute correctly. - -The SDRC supports a mode where some of the chip select lines are -swapped in order to make SDRAM look like a synchronous ROM. Setting -this bit means that the RAM will present as a contiguous array. Some -programmers prefer this to the discontiguous layout. Be aware that -may be a penalty for this feature where some some configurations of -memory are significantly reduced; i.e. 64MiB of RAM appears as only 32 -MiB. - -There are a couple of configuration options to override the default -behavior. When the SROMLL bit is set and memory appears as a -contiguous array, there is no reason to support NUMA. -CONFIG_LH7A40X_CONTIGMEM disables NUMA support. When physical memory -is discontiguous, the memory tables are organized such that there are -two banks per nodes with a small gap between them. This layout wastes -some kernel memory for page tables representing non-existent memory. -CONFIG_LH7A40X_ONE_BANK_PER_NODE optimizes the node tables such that -there are no gaps. These options control the low level organization -of the memory management tables in ways that may prevent the kernel -from booting or may cause the kernel to allocated excessively large -page tables. Be warned. Only change these options if you know what -you are doing. The default behavior is a reasonable compromise that -will suit all users. - --- - -A typical 32MiB system with the default configuration options will -find physical memory managed as follows. - - node 0: 0xc0000000 4MiB - 0xc1000000 4MiB - node 1: 0xc4000000 4MiB - 0xc5000000 4MiB - node 2: 0xc8000000 4MiB - 0xc9000000 4MiB - node 3: 0xcc000000 4MiB - 0xcd000000 4MiB - -Setting CONFIG_LH7A40X_ONE_BANK_PER_NODE will put each bank into a -separate node. diff --git a/Documentation/arm/Sharp-LH/VectoredInterruptController b/Documentation/arm/Sharp-LH/VectoredInterruptController deleted file mode 100644 index 23047e9861e..00000000000 --- a/Documentation/arm/Sharp-LH/VectoredInterruptController +++ /dev/null @@ -1,80 +0,0 @@ -README on the Vectored Interrupt Controller of the LH7A404 -========================================================== - -The 404 revision of the LH7A40X series comes with two vectored -interrupts controllers. While the kernel does use some of the -features of these devices, it is far from the purpose for which they -were designed. - -When this README was written, the implementation of the VICs was in -flux. It is possible that some details, especially with priorities, -will change. - -The VIC support code is inspired by routines written by Sharp. - - -Priority Control ----------------- - -The significant reason for using the VIC's vectoring is to control -interrupt priorities. There are two tables in -arch/arm/mach-lh7a40x/irq-lh7a404.c that look something like this. - - static unsigned char irq_pri_vic1[] = { IRQ_GPIO3INTR, }; - static unsigned char irq_pri_vic2[] = { - IRQ_T3UI, IRQ_GPIO7INTR, - IRQ_UART1INTR, IRQ_UART2INTR, IRQ_UART3INTR, }; - -The initialization code reads these tables and inserts a vector -address and enable for each indicated IRQ. Vectored interrupts have -higher priority than non-vectored interrupts. So, on VIC1, -IRQ_GPIO3INTR will be served before any other non-FIQ interrupt. Due -to the way that the vectoring works, IRQ_T3UI is the next highest -priority followed by the other vectored interrupts on VIC2. After -that, the non-vectored interrupts are scanned in VIC1 then in VIC2. - - -ISR ---- - -The interrupt service routine macro get_irqnr() in -arch/arm/kernel/entry-armv.S scans the VICs for the next active -interrupt. The vectoring makes this code somewhat larger than it was -before using vectoring (refer to the LH7A400 implementation). In the -case where an interrupt is vectored, the implementation will tend to -be faster than the non-vectored version. However, the worst-case path -is longer. - -It is worth noting that at present, there is no need to read -VIC2_VECTADDR because the register appears to be shared between the -controllers. The code is written such that if this changes, it ought -to still work properly. - - -Vector Addresses ----------------- - -The proper use of the vectoring hardware would jump to the ISR -specified by the vectoring address. Linux isn't structured to take -advantage of this feature, though it might be possible to change -things to support it. - -In this implementation, the vectoring address is used to speed the -search for the active IRQ. The address is coded such that the lowest -6 bits store the IRQ number for vectored interrupts. These numbers -correspond to the bits in the interrupt status registers. IRQ zero is -the lowest interrupt bit in VIC1. IRQ 32 is the lowest interrupt bit -in VIC2. Because zero is a valid IRQ number and because we cannot -detect whether or not there is a valid vectoring address if that -address is zero, the eigth bit (0x100) is set for vectored interrupts. -The address for IRQ 0x18 (VIC2) is 0x118. Only the ninth bit is set -for the default handler on VIC1 and only the tenth bit is set for the -default handler on VIC2. - -In other words. - - 0x000 - no active interrupt - 0x1ii - vectored interrupt 0xii - 0x2xx - unvectored interrupt on VIC1 (xx is don't care) - 0x4xx - unvectored interrupt on VIC2 (xx is don't care) - diff --git a/Documentation/arm/cluster-pm-race-avoidance.txt b/Documentation/arm/cluster-pm-race-avoidance.txt new file mode 100644 index 00000000000..750b6fc24af --- /dev/null +++ b/Documentation/arm/cluster-pm-race-avoidance.txt @@ -0,0 +1,498 @@ +Cluster-wide Power-up/power-down race avoidance algorithm +========================================================= + +This file documents the algorithm which is used to coordinate CPU and +cluster setup and teardown operations and to manage hardware coherency +controls safely. + +The section "Rationale" explains what the algorithm is for and why it is +needed. "Basic model" explains general concepts using a simplified view +of the system. The other sections explain the actual details of the +algorithm in use. + + +Rationale +--------- + +In a system containing multiple CPUs, it is desirable to have the +ability to turn off individual CPUs when the system is idle, reducing +power consumption and thermal dissipation. + +In a system containing multiple clusters of CPUs, it is also desirable +to have the ability to turn off entire clusters. + +Turning entire clusters off and on is a risky business, because it +involves performing potentially destructive operations affecting a group +of independently running CPUs, while the OS continues to run. This +means that we need some coordination in order to ensure that critical +cluster-level operations are only performed when it is truly safe to do +so. + +Simple locking may not be sufficient to solve this problem, because +mechanisms like Linux spinlocks may rely on coherency mechanisms which +are not immediately enabled when a cluster powers up. Since enabling or +disabling those mechanisms may itself be a non-atomic operation (such as +writing some hardware registers and invalidating large caches), other +methods of coordination are required in order to guarantee safe +power-down and power-up at the cluster level. + +The mechanism presented in this document describes a coherent memory +based protocol for performing the needed coordination. It aims to be as +lightweight as possible, while providing the required safety properties. + + +Basic model +----------- + +Each cluster and CPU is assigned a state, as follows: + + DOWN + COMING_UP + UP + GOING_DOWN + + +---------> UP ----------+ + | v + + COMING_UP GOING_DOWN + + ^ | + +--------- DOWN <--------+ + + +DOWN: The CPU or cluster is not coherent, and is either powered off or + suspended, or is ready to be powered off or suspended. + +COMING_UP: The CPU or cluster has committed to moving to the UP state. + It may be part way through the process of initialisation and + enabling coherency. + +UP: The CPU or cluster is active and coherent at the hardware + level. A CPU in this state is not necessarily being used + actively by the kernel. + +GOING_DOWN: The CPU or cluster has committed to moving to the DOWN + state. It may be part way through the process of teardown and + coherency exit. + + +Each CPU has one of these states assigned to it at any point in time. +The CPU states are described in the "CPU state" section, below. + +Each cluster is also assigned a state, but it is necessary to split the +state value into two parts (the "cluster" state and "inbound" state) and +to introduce additional states in order to avoid races between different +CPUs in the cluster simultaneously modifying the state. The cluster- +level states are described in the "Cluster state" section. + +To help distinguish the CPU states from cluster states in this +discussion, the state names are given a CPU_ prefix for the CPU states, +and a CLUSTER_ or INBOUND_ prefix for the cluster states. + + +CPU state +--------- + +In this algorithm, each individual core in a multi-core processor is +referred to as a "CPU". CPUs are assumed to be single-threaded: +therefore, a CPU can only be doing one thing at a single point in time. + +This means that CPUs fit the basic model closely. + +The algorithm defines the following states for each CPU in the system: + + CPU_DOWN + CPU_COMING_UP + CPU_UP + CPU_GOING_DOWN + + cluster setup and + CPU setup complete policy decision + +-----------> CPU_UP ------------+ + | v + + CPU_COMING_UP CPU_GOING_DOWN + + ^ | + +----------- CPU_DOWN <----------+ + policy decision CPU teardown complete + or hardware event + + +The definitions of the four states correspond closely to the states of +the basic model. + +Transitions between states occur as follows. + +A trigger event (spontaneous) means that the CPU can transition to the +next state as a result of making local progress only, with no +requirement for any external event to happen. + + +CPU_DOWN: + + A CPU reaches the CPU_DOWN state when it is ready for + power-down. On reaching this state, the CPU will typically + power itself down or suspend itself, via a WFI instruction or a + firmware call. + + Next state: CPU_COMING_UP + Conditions: none + + Trigger events: + + a) an explicit hardware power-up operation, resulting + from a policy decision on another CPU; + + b) a hardware event, such as an interrupt. + + +CPU_COMING_UP: + + A CPU cannot start participating in hardware coherency until the + cluster is set up and coherent. If the cluster is not ready, + then the CPU will wait in the CPU_COMING_UP state until the + cluster has been set up. + + Next state: CPU_UP + Conditions: The CPU's parent cluster must be in CLUSTER_UP. + Trigger events: Transition of the parent cluster to CLUSTER_UP. + + Refer to the "Cluster state" section for a description of the + CLUSTER_UP state. + + +CPU_UP: + When a CPU reaches the CPU_UP state, it is safe for the CPU to + start participating in local coherency. + + This is done by jumping to the kernel's CPU resume code. + + Note that the definition of this state is slightly different + from the basic model definition: CPU_UP does not mean that the + CPU is coherent yet, but it does mean that it is safe to resume + the kernel. The kernel handles the rest of the resume + procedure, so the remaining steps are not visible as part of the + race avoidance algorithm. + + The CPU remains in this state until an explicit policy decision + is made to shut down or suspend the CPU. + + Next state: CPU_GOING_DOWN + Conditions: none + Trigger events: explicit policy decision + + +CPU_GOING_DOWN: + + While in this state, the CPU exits coherency, including any + operations required to achieve this (such as cleaning data + caches). + + Next state: CPU_DOWN + Conditions: local CPU teardown complete + Trigger events: (spontaneous) + + +Cluster state +------------- + +A cluster is a group of connected CPUs with some common resources. +Because a cluster contains multiple CPUs, it can be doing multiple +things at the same time. This has some implications. In particular, a +CPU can start up while another CPU is tearing the cluster down. + +In this discussion, the "outbound side" is the view of the cluster state +as seen by a CPU tearing the cluster down. The "inbound side" is the +view of the cluster state as seen by a CPU setting the CPU up. + +In order to enable safe coordination in such situations, it is important +that a CPU which is setting up the cluster can advertise its state +independently of the CPU which is tearing down the cluster. For this +reason, the cluster state is split into two parts: + + "cluster" state: The global state of the cluster; or the state + on the outbound side: + + CLUSTER_DOWN + CLUSTER_UP + CLUSTER_GOING_DOWN + + "inbound" state: The state of the cluster on the inbound side. + + INBOUND_NOT_COMING_UP + INBOUND_COMING_UP + + + The different pairings of these states results in six possible + states for the cluster as a whole: + + CLUSTER_UP + +==========> INBOUND_NOT_COMING_UP -------------+ + # | + | + CLUSTER_UP <----+ | + INBOUND_COMING_UP | v + + ^ CLUSTER_GOING_DOWN CLUSTER_GOING_DOWN + # INBOUND_COMING_UP <=== INBOUND_NOT_COMING_UP + + CLUSTER_DOWN | | + INBOUND_COMING_UP <----+ | + | + ^ | + +=========== CLUSTER_DOWN <------------+ + INBOUND_NOT_COMING_UP + + Transitions -----> can only be made by the outbound CPU, and + only involve changes to the "cluster" state. + + Transitions ===##> can only be made by the inbound CPU, and only + involve changes to the "inbound" state, except where there is no + further transition possible on the outbound side (i.e., the + outbound CPU has put the cluster into the CLUSTER_DOWN state). + + The race avoidance algorithm does not provide a way to determine + which exact CPUs within the cluster play these roles. This must + be decided in advance by some other means. Refer to the section + "Last man and first man selection" for more explanation. + + + CLUSTER_DOWN/INBOUND_NOT_COMING_UP is the only state where the + cluster can actually be powered down. + + The parallelism of the inbound and outbound CPUs is observed by + the existence of two different paths from CLUSTER_GOING_DOWN/ + INBOUND_NOT_COMING_UP (corresponding to GOING_DOWN in the basic + model) to CLUSTER_DOWN/INBOUND_COMING_UP (corresponding to + COMING_UP in the basic model). The second path avoids cluster + teardown completely. + + CLUSTER_UP/INBOUND_COMING_UP is equivalent to UP in the basic + model. The final transition to CLUSTER_UP/INBOUND_NOT_COMING_UP + is trivial and merely resets the state machine ready for the + next cycle. + + Details of the allowable transitions follow. + + The next state in each case is notated + + <cluster state>/<inbound state> (<transitioner>) + + where the <transitioner> is the side on which the transition + can occur; either the inbound or the outbound side. + + +CLUSTER_DOWN/INBOUND_NOT_COMING_UP: + + Next state: CLUSTER_DOWN/INBOUND_COMING_UP (inbound) + Conditions: none + Trigger events: + + a) an explicit hardware power-up operation, resulting + from a policy decision on another CPU; + + b) a hardware event, such as an interrupt. + + +CLUSTER_DOWN/INBOUND_COMING_UP: + + In this state, an inbound CPU sets up the cluster, including + enabling of hardware coherency at the cluster level and any + other operations (such as cache invalidation) which are required + in order to achieve this. + + The purpose of this state is to do sufficient cluster-level + setup to enable other CPUs in the cluster to enter coherency + safely. + + Next state: CLUSTER_UP/INBOUND_COMING_UP (inbound) + Conditions: cluster-level setup and hardware coherency complete + Trigger events: (spontaneous) + + +CLUSTER_UP/INBOUND_COMING_UP: + + Cluster-level setup is complete and hardware coherency is + enabled for the cluster. Other CPUs in the cluster can safely + enter coherency. + + This is a transient state, leading immediately to + CLUSTER_UP/INBOUND_NOT_COMING_UP. All other CPUs on the cluster + should consider treat these two states as equivalent. + + Next state: CLUSTER_UP/INBOUND_NOT_COMING_UP (inbound) + Conditions: none + Trigger events: (spontaneous) + + +CLUSTER_UP/INBOUND_NOT_COMING_UP: + + Cluster-level setup is complete and hardware coherency is + enabled for the cluster. Other CPUs in the cluster can safely + enter coherency. + + The cluster will remain in this state until a policy decision is + made to power the cluster down. + + Next state: CLUSTER_GOING_DOWN/INBOUND_NOT_COMING_UP (outbound) + Conditions: none + Trigger events: policy decision to power down the cluster + + +CLUSTER_GOING_DOWN/INBOUND_NOT_COMING_UP: + + An outbound CPU is tearing the cluster down. The selected CPU + must wait in this state until all CPUs in the cluster are in the + CPU_DOWN state. + + When all CPUs are in the CPU_DOWN state, the cluster can be torn + down, for example by cleaning data caches and exiting + cluster-level coherency. + + To avoid wasteful unnecessary teardown operations, the outbound + should check the inbound cluster state for asynchronous + transitions to INBOUND_COMING_UP. Alternatively, individual + CPUs can be checked for entry into CPU_COMING_UP or CPU_UP. + + + Next states: + + CLUSTER_DOWN/INBOUND_NOT_COMING_UP (outbound) + Conditions: cluster torn down and ready to power off + Trigger events: (spontaneous) + + CLUSTER_GOING_DOWN/INBOUND_COMING_UP (inbound) + Conditions: none + Trigger events: + + a) an explicit hardware power-up operation, + resulting from a policy decision on another + CPU; + + b) a hardware event, such as an interrupt. + + +CLUSTER_GOING_DOWN/INBOUND_COMING_UP: + + The cluster is (or was) being torn down, but another CPU has + come online in the meantime and is trying to set up the cluster + again. + + If the outbound CPU observes this state, it has two choices: + + a) back out of teardown, restoring the cluster to the + CLUSTER_UP state; + + b) finish tearing the cluster down and put the cluster + in the CLUSTER_DOWN state; the inbound CPU will + set up the cluster again from there. + + Choice (a) permits the removal of some latency by avoiding + unnecessary teardown and setup operations in situations where + the cluster is not really going to be powered down. + + + Next states: + + CLUSTER_UP/INBOUND_COMING_UP (outbound) + Conditions: cluster-level setup and hardware + coherency complete + Trigger events: (spontaneous) + + CLUSTER_DOWN/INBOUND_COMING_UP (outbound) + Conditions: cluster torn down and ready to power off + Trigger events: (spontaneous) + + +Last man and First man selection +-------------------------------- + +The CPU which performs cluster tear-down operations on the outbound side +is commonly referred to as the "last man". + +The CPU which performs cluster setup on the inbound side is commonly +referred to as the "first man". + +The race avoidance algorithm documented above does not provide a +mechanism to choose which CPUs should play these roles. + + +Last man: + +When shutting down the cluster, all the CPUs involved are initially +executing Linux and hence coherent. Therefore, ordinary spinlocks can +be used to select a last man safely, before the CPUs become +non-coherent. + + +First man: + +Because CPUs may power up asynchronously in response to external wake-up +events, a dynamic mechanism is needed to make sure that only one CPU +attempts to play the first man role and do the cluster-level +initialisation: any other CPUs must wait for this to complete before +proceeding. + +Cluster-level initialisation may involve actions such as configuring +coherency controls in the bus fabric. + +The current implementation in mcpm_head.S uses a separate mutual exclusion +mechanism to do this arbitration. This mechanism is documented in +detail in vlocks.txt. + + +Features and Limitations +------------------------ + +Implementation: + + The current ARM-based implementation is split between + arch/arm/common/mcpm_head.S (low-level inbound CPU operations) and + arch/arm/common/mcpm_entry.c (everything else): + + __mcpm_cpu_going_down() signals the transition of a CPU to the + CPU_GOING_DOWN state. + + __mcpm_cpu_down() signals the transition of a CPU to the CPU_DOWN + state. + + A CPU transitions to CPU_COMING_UP and then to CPU_UP via the + low-level power-up code in mcpm_head.S. This could + involve CPU-specific setup code, but in the current + implementation it does not. + + __mcpm_outbound_enter_critical() and __mcpm_outbound_leave_critical() + handle transitions from CLUSTER_UP to CLUSTER_GOING_DOWN + and from there to CLUSTER_DOWN or back to CLUSTER_UP (in + the case of an aborted cluster power-down). + + These functions are more complex than the __mcpm_cpu_*() + functions due to the extra inter-CPU coordination which + is needed for safe transitions at the cluster level. + + A cluster transitions from CLUSTER_DOWN back to CLUSTER_UP via + the low-level power-up code in mcpm_head.S. This + typically involves platform-specific setup code, + provided by the platform-specific power_up_setup + function registered via mcpm_sync_init. + +Deep topologies: + + As currently described and implemented, the algorithm does not + support CPU topologies involving more than two levels (i.e., + clusters of clusters are not supported). The algorithm could be + extended by replicating the cluster-level states for the + additional topological levels, and modifying the transition + rules for the intermediate (non-outermost) cluster levels. + + +Colophon +-------- + +Originally created and documented by Dave Martin for Linaro Limited, in +collaboration with Nicolas Pitre and Achin Gupta. + +Copyright (C) 2012-2013 Linaro Limited +Distributed under the terms of Version 2 of the GNU General Public +License, as defined in linux/COPYING. diff --git a/Documentation/arm/empeg/README b/Documentation/arm/empeg/README deleted file mode 100644 index 09cc8d03ae5..00000000000 --- a/Documentation/arm/empeg/README +++ /dev/null @@ -1,13 +0,0 @@ -Empeg, Ltd's Empeg MP3 Car Audio Player - -The initial design is to go in your car, but you can use it at home, on a -boat... almost anywhere. The principle is to store CD-quality music using -MPEG technology onto a hard disk in the unit, and use the power of the -embedded computer to serve up the music you want. - -For more details, see: - - http://www.empeg.com - - - diff --git a/Documentation/arm/empeg/ir.txt b/Documentation/arm/empeg/ir.txt deleted file mode 100644 index 10a29745016..00000000000 --- a/Documentation/arm/empeg/ir.txt +++ /dev/null @@ -1,49 +0,0 @@ -Infra-red driver documentation. - -Mike Crowe <mac@empeg.com> -(C) Empeg Ltd 1999 - -Not a lot here yet :-) - -The Kenwood KCA-R6A remote control generates a sequence like the following: - -Go low for approx 16T (Around 9000us) -Go high for approx 8T (Around 4000us) -Go low for less than 2T (Around 750us) - -For each of the 32 bits - Go high for more than 2T (Around 1500us) == 1 - Go high for less than T (Around 400us) == 0 - Go low for less than 2T (Around 750us) - -Rather than repeat a signal when the button is held down certain buttons -generate the following code to indicate repetition. - -Go low for approx 16T -Go high for approx 4T -Go low for less than 2T - -(By removing the <2T from the start of the sequence and placing at the end - it can be considered a stop bit but I found it easier to deal with it at - the start). - -The 32 bits are encoded as XxYy where x and y are the actual data values -while X and Y are the logical inverses of the associated data values. Using -LSB first yields sensible codes for the numbers. - -All codes are of the form b9xx - -The numeric keys generate the code 0x where x is the number pressed. - -Tuner 1c -Tape 1d -CD 1e -CD-MD-CH 1f -Track- 0a -Track+ 0b -Rewind 0c -FF 0d -DNPP 5e -Play/Pause 0e -Vol+ 14 -Vol- 15 diff --git a/Documentation/arm/empeg/mkdevs b/Documentation/arm/empeg/mkdevs deleted file mode 100644 index 7a85e28d14f..00000000000 --- a/Documentation/arm/empeg/mkdevs +++ /dev/null @@ -1,11 +0,0 @@ -#!/bin/sh -mknod /dev/display c 244 0 -mknod /dev/ir c 242 0 -mknod /dev/usb0 c 243 0 -mknod /dev/audio c 245 4 -mknod /dev/dsp c 245 3 -mknod /dev/mixer c 245 0 -mknod /dev/empeg_state c 246 0 -mknod /dev/radio0 c 81 64 -ln -sf radio0 radio -ln -sf usb0 usb diff --git a/Documentation/arm/firmware.txt b/Documentation/arm/firmware.txt new file mode 100644 index 00000000000..c2e468fe7b0 --- /dev/null +++ b/Documentation/arm/firmware.txt @@ -0,0 +1,88 @@ +Interface for registering and calling firmware-specific operations for ARM. +---- +Written by Tomasz Figa <t.figa@samsung.com> + +Some boards are running with secure firmware running in TrustZone secure +world, which changes the way some things have to be initialized. This makes +a need to provide an interface for such platforms to specify available firmware +operations and call them when needed. + +Firmware operations can be specified using struct firmware_ops + + struct firmware_ops { + /* + * Enters CPU idle mode + */ + int (*do_idle)(void); + /* + * Sets boot address of specified physical CPU + */ + int (*set_cpu_boot_addr)(int cpu, unsigned long boot_addr); + /* + * Boots specified physical CPU + */ + int (*cpu_boot)(int cpu); + /* + * Initializes L2 cache + */ + int (*l2x0_init)(void); + }; + +and then registered with register_firmware_ops function + + void register_firmware_ops(const struct firmware_ops *ops) + +the ops pointer must be non-NULL. + +There is a default, empty set of operations provided, so there is no need to +set anything if platform does not require firmware operations. + +To call a firmware operation, a helper macro is provided + + #define call_firmware_op(op, ...) \ + ((firmware_ops->op) ? firmware_ops->op(__VA_ARGS__) : (-ENOSYS)) + +the macro checks if the operation is provided and calls it or otherwise returns +-ENOSYS to signal that given operation is not available (for example, to allow +fallback to legacy operation). + +Example of registering firmware operations: + + /* board file */ + + static int platformX_do_idle(void) + { + /* tell platformX firmware to enter idle */ + return 0; + } + + static int platformX_cpu_boot(int i) + { + /* tell platformX firmware to boot CPU i */ + return 0; + } + + static const struct firmware_ops platformX_firmware_ops = { + .do_idle = exynos_do_idle, + .cpu_boot = exynos_cpu_boot, + /* other operations not available on platformX */ + }; + + /* init_early callback of machine descriptor */ + static void __init board_init_early(void) + { + register_firmware_ops(&platformX_firmware_ops); + } + +Example of using a firmware operation: + + /* some platform code, e.g. SMP initialization */ + + __raw_writel(virt_to_phys(exynos4_secondary_startup), + CPU1_BOOT_REG); + + /* Call Exynos specific smc call */ + if (call_firmware_op(cpu_boot, cpu) == -ENOSYS) + cpu_boot_legacy(...); /* Try legacy way */ + + gic_raise_softirq(cpumask_of(cpu), 1); diff --git a/Documentation/arm/kernel_mode_neon.txt b/Documentation/arm/kernel_mode_neon.txt new file mode 100644 index 00000000000..525452726d3 --- /dev/null +++ b/Documentation/arm/kernel_mode_neon.txt @@ -0,0 +1,121 @@ +Kernel mode NEON +================ + +TL;DR summary +------------- +* Use only NEON instructions, or VFP instructions that don't rely on support + code +* Isolate your NEON code in a separate compilation unit, and compile it with + '-mfpu=neon -mfloat-abi=softfp' +* Put kernel_neon_begin() and kernel_neon_end() calls around the calls into your + NEON code +* Don't sleep in your NEON code, and be aware that it will be executed with + preemption disabled + + +Introduction +------------ +It is possible to use NEON instructions (and in some cases, VFP instructions) in +code that runs in kernel mode. However, for performance reasons, the NEON/VFP +register file is not preserved and restored at every context switch or taken +exception like the normal register file is, so some manual intervention is +required. Furthermore, special care is required for code that may sleep [i.e., +may call schedule()], as NEON or VFP instructions will be executed in a +non-preemptible section for reasons outlined below. + + +Lazy preserve and restore +------------------------- +The NEON/VFP register file is managed using lazy preserve (on UP systems) and +lazy restore (on both SMP and UP systems). This means that the register file is +kept 'live', and is only preserved and restored when multiple tasks are +contending for the NEON/VFP unit (or, in the SMP case, when a task migrates to +another core). Lazy restore is implemented by disabling the NEON/VFP unit after +every context switch, resulting in a trap when subsequently a NEON/VFP +instruction is issued, allowing the kernel to step in and perform the restore if +necessary. + +Any use of the NEON/VFP unit in kernel mode should not interfere with this, so +it is required to do an 'eager' preserve of the NEON/VFP register file, and +enable the NEON/VFP unit explicitly so no exceptions are generated on first +subsequent use. This is handled by the function kernel_neon_begin(), which +should be called before any kernel mode NEON or VFP instructions are issued. +Likewise, the NEON/VFP unit should be disabled again after use to make sure user +mode will hit the lazy restore trap upon next use. This is handled by the +function kernel_neon_end(). + + +Interruptions in kernel mode +---------------------------- +For reasons of performance and simplicity, it was decided that there shall be no +preserve/restore mechanism for the kernel mode NEON/VFP register contents. This +implies that interruptions of a kernel mode NEON section can only be allowed if +they are guaranteed not to touch the NEON/VFP registers. For this reason, the +following rules and restrictions apply in the kernel: +* NEON/VFP code is not allowed in interrupt context; +* NEON/VFP code is not allowed to sleep; +* NEON/VFP code is executed with preemption disabled. + +If latency is a concern, it is possible to put back to back calls to +kernel_neon_end() and kernel_neon_begin() in places in your code where none of +the NEON registers are live. (Additional calls to kernel_neon_begin() should be +reasonably cheap if no context switch occurred in the meantime) + + +VFP and support code +-------------------- +Earlier versions of VFP (prior to version 3) rely on software support for things +like IEEE-754 compliant underflow handling etc. When the VFP unit needs such +software assistance, it signals the kernel by raising an undefined instruction +exception. The kernel responds by inspecting the VFP control registers and the +current instruction and arguments, and emulates the instruction in software. + +Such software assistance is currently not implemented for VFP instructions +executed in kernel mode. If such a condition is encountered, the kernel will +fail and generate an OOPS. + + +Separating NEON code from ordinary code +--------------------------------------- +The compiler is not aware of the special significance of kernel_neon_begin() and +kernel_neon_end(), i.e., that it is only allowed to issue NEON/VFP instructions +between calls to these respective functions. Furthermore, GCC may generate NEON +instructions of its own at -O3 level if -mfpu=neon is selected, and even if the +kernel is currently compiled at -O2, future changes may result in NEON/VFP +instructions appearing in unexpected places if no special care is taken. + +Therefore, the recommended and only supported way of using NEON/VFP in the +kernel is by adhering to the following rules: +* isolate the NEON code in a separate compilation unit and compile it with + '-mfpu=neon -mfloat-abi=softfp'; +* issue the calls to kernel_neon_begin(), kernel_neon_end() as well as the calls + into the unit containing the NEON code from a compilation unit which is *not* + built with the GCC flag '-mfpu=neon' set. + +As the kernel is compiled with '-msoft-float', the above will guarantee that +both NEON and VFP instructions will only ever appear in designated compilation +units at any optimization level. + + +NEON assembler +-------------- +NEON assembler is supported with no additional caveats as long as the rules +above are followed. + + +NEON code generated by GCC +-------------------------- +The GCC option -ftree-vectorize (implied by -O3) tries to exploit implicit +parallelism, and generates NEON code from ordinary C source code. This is fully +supported as long as the rules above are followed. + + +NEON intrinsics +--------------- +NEON intrinsics are also supported. However, as code using NEON intrinsics +relies on the GCC header <arm_neon.h>, (which #includes <stdint.h>), you should +observe the following in addition to the rules above: +* Compile the unit containing the NEON intrinsics with '-ffreestanding' so GCC + uses its builtin version of <stdint.h> (this is a C99 header which the kernel + does not supply); +* Include <arm_neon.h> last, or at least after <linux/types.h> diff --git a/Documentation/arm/kernel_user_helpers.txt b/Documentation/arm/kernel_user_helpers.txt new file mode 100644 index 00000000000..5673594717c --- /dev/null +++ b/Documentation/arm/kernel_user_helpers.txt @@ -0,0 +1,267 @@ +Kernel-provided User Helpers +============================ + +These are segment of kernel provided user code reachable from user space +at a fixed address in kernel memory. This is used to provide user space +with some operations which require kernel help because of unimplemented +native feature and/or instructions in many ARM CPUs. The idea is for this +code to be executed directly in user mode for best efficiency but which is +too intimate with the kernel counter part to be left to user libraries. +In fact this code might even differ from one CPU to another depending on +the available instruction set, or whether it is a SMP systems. In other +words, the kernel reserves the right to change this code as needed without +warning. Only the entry points and their results as documented here are +guaranteed to be stable. + +This is different from (but doesn't preclude) a full blown VDSO +implementation, however a VDSO would prevent some assembly tricks with +constants that allows for efficient branching to those code segments. And +since those code segments only use a few cycles before returning to user +code, the overhead of a VDSO indirect far call would add a measurable +overhead to such minimalistic operations. + +User space is expected to bypass those helpers and implement those things +inline (either in the code emitted directly by the compiler, or part of +the implementation of a library call) when optimizing for a recent enough +processor that has the necessary native support, but only if resulting +binaries are already to be incompatible with earlier ARM processors due to +usage of similar native instructions for other things. In other words +don't make binaries unable to run on earlier processors just for the sake +of not using these kernel helpers if your compiled code is not going to +use new instructions for other purpose. + +New helpers may be added over time, so an older kernel may be missing some +helpers present in a newer kernel. For this reason, programs must check +the value of __kuser_helper_version (see below) before assuming that it is +safe to call any particular helper. This check should ideally be +performed only once at process startup time, and execution aborted early +if the required helpers are not provided by the kernel version that +process is running on. + +kuser_helper_version +-------------------- + +Location: 0xffff0ffc + +Reference declaration: + + extern int32_t __kuser_helper_version; + +Definition: + + This field contains the number of helpers being implemented by the + running kernel. User space may read this to determine the availability + of a particular helper. + +Usage example: + +#define __kuser_helper_version (*(int32_t *)0xffff0ffc) + +void check_kuser_version(void) +{ + if (__kuser_helper_version < 2) { + fprintf(stderr, "can't do atomic operations, kernel too old\n"); + abort(); + } +} + +Notes: + + User space may assume that the value of this field never changes + during the lifetime of any single process. This means that this + field can be read once during the initialisation of a library or + startup phase of a program. + +kuser_get_tls +------------- + +Location: 0xffff0fe0 + +Reference prototype: + + void * __kuser_get_tls(void); + +Input: + + lr = return address + +Output: + + r0 = TLS value + +Clobbered registers: + + none + +Definition: + + Get the TLS value as previously set via the __ARM_NR_set_tls syscall. + +Usage example: + +typedef void * (__kuser_get_tls_t)(void); +#define __kuser_get_tls (*(__kuser_get_tls_t *)0xffff0fe0) + +void foo() +{ + void *tls = __kuser_get_tls(); + printf("TLS = %p\n", tls); +} + +Notes: + + - Valid only if __kuser_helper_version >= 1 (from kernel version 2.6.12). + +kuser_cmpxchg +------------- + +Location: 0xffff0fc0 + +Reference prototype: + + int __kuser_cmpxchg(int32_t oldval, int32_t newval, volatile int32_t *ptr); + +Input: + + r0 = oldval + r1 = newval + r2 = ptr + lr = return address + +Output: + + r0 = success code (zero or non-zero) + C flag = set if r0 == 0, clear if r0 != 0 + +Clobbered registers: + + r3, ip, flags + +Definition: + + Atomically store newval in *ptr only if *ptr is equal to oldval. + Return zero if *ptr was changed or non-zero if no exchange happened. + The C flag is also set if *ptr was changed to allow for assembly + optimization in the calling code. + +Usage example: + +typedef int (__kuser_cmpxchg_t)(int oldval, int newval, volatile int *ptr); +#define __kuser_cmpxchg (*(__kuser_cmpxchg_t *)0xffff0fc0) + +int atomic_add(volatile int *ptr, int val) +{ + int old, new; + + do { + old = *ptr; + new = old + val; + } while(__kuser_cmpxchg(old, new, ptr)); + + return new; +} + +Notes: + + - This routine already includes memory barriers as needed. + + - Valid only if __kuser_helper_version >= 2 (from kernel version 2.6.12). + +kuser_memory_barrier +-------------------- + +Location: 0xffff0fa0 + +Reference prototype: + + void __kuser_memory_barrier(void); + +Input: + + lr = return address + +Output: + + none + +Clobbered registers: + + none + +Definition: + + Apply any needed memory barrier to preserve consistency with data modified + manually and __kuser_cmpxchg usage. + +Usage example: + +typedef void (__kuser_dmb_t)(void); +#define __kuser_dmb (*(__kuser_dmb_t *)0xffff0fa0) + +Notes: + + - Valid only if __kuser_helper_version >= 3 (from kernel version 2.6.15). + +kuser_cmpxchg64 +--------------- + +Location: 0xffff0f60 + +Reference prototype: + + int __kuser_cmpxchg64(const int64_t *oldval, + const int64_t *newval, + volatile int64_t *ptr); + +Input: + + r0 = pointer to oldval + r1 = pointer to newval + r2 = pointer to target value + lr = return address + +Output: + + r0 = success code (zero or non-zero) + C flag = set if r0 == 0, clear if r0 != 0 + +Clobbered registers: + + r3, lr, flags + +Definition: + + Atomically store the 64-bit value pointed by *newval in *ptr only if *ptr + is equal to the 64-bit value pointed by *oldval. Return zero if *ptr was + changed or non-zero if no exchange happened. + + The C flag is also set if *ptr was changed to allow for assembly + optimization in the calling code. + +Usage example: + +typedef int (__kuser_cmpxchg64_t)(const int64_t *oldval, + const int64_t *newval, + volatile int64_t *ptr); +#define __kuser_cmpxchg64 (*(__kuser_cmpxchg64_t *)0xffff0f60) + +int64_t atomic_add64(volatile int64_t *ptr, int64_t val) +{ + int64_t old, new; + + do { + old = *ptr; + new = old + val; + } while(__kuser_cmpxchg64(&old, &new, ptr)); + + return new; +} + +Notes: + + - This routine already includes memory barriers as needed. + + - Due to the length of this sequence, this spans 2 conventional kuser + "slots", therefore 0xffff0f80 is not used as a valid entry point. + + - Valid only if __kuser_helper_version >= 5 (from kernel version 3.1). diff --git a/Documentation/arm/mem_alignment b/Documentation/arm/mem_alignment index d145ccca169..c7c7a114c78 100644 --- a/Documentation/arm/mem_alignment +++ b/Documentation/arm/mem_alignment @@ -24,7 +24,7 @@ real bad - it changes the behaviour of all unaligned instructions in user space, and might cause programs to fail unexpectedly. To change the alignment trap behavior, simply echo a number into -/proc/sys/debug/alignment. The number is made up from various bits: +/proc/cpu/alignment. The number is made up from various bits: bit behavior when set --- ----------------- diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt index dc6045577a8..38dc06d0a79 100644 --- a/Documentation/arm/memory.txt +++ b/Documentation/arm/memory.txt @@ -21,6 +21,8 @@ ffff8000 ffffffff copy_user_page / clear_user_page use. For SA11xx and Xscale, this is used to setup a minicache mapping. +ffff4000 ffffffff cache aliasing on ARMv6 and later CPUs. + ffff1000 ffff7fff Reserved. Platforms must not use this address range. @@ -29,28 +31,40 @@ ffff0000 ffff0fff CPU vector page. CPU supports vector relocation (control register V bit.) -ffc00000 fffeffff DMA memory mapping region. Memory returned - by the dma_alloc_xxx functions will be - dynamically mapped here. +fffe0000 fffeffff XScale cache flush area. This is used + in proc-xscale.S to flush the whole data + cache. (XScale does not have TCM.) + +fffe8000 fffeffff DTCM mapping area for platforms with + DTCM mounted inside the CPU. -ff000000 ffbfffff Reserved for future expansion of DMA - mapping region. +fffe0000 fffe7fff ITCM mapping area for platforms with + ITCM mounted inside the CPU. -VMALLOC_END feffffff Free for platform use, recommended. - VMALLOC_END must be aligned to a 2MB - boundary. +ffc00000 ffdfffff Fixmap mapping region. Addresses provided + by fix_to_virt() will be located here. + +fee00000 feffffff Mapping of PCI I/O space. This is a static + mapping within the vmalloc space. VMALLOC_START VMALLOC_END-1 vmalloc() / ioremap() space. Memory returned by vmalloc/ioremap will be dynamically placed in this region. - VMALLOC_START may be based upon the value - of the high_memory variable. + Machine specific static mappings are also + located here through iotable_init(). + VMALLOC_START is based upon the value + of the high_memory variable, and VMALLOC_END + is equal to 0xff000000. PAGE_OFFSET high_memory-1 Kernel direct-mapped RAM region. This maps the platforms RAM, and typically maps all platform RAM in a 1:1 relationship. -TASK_SIZE PAGE_OFFSET-1 Kernel module space +PKMAP_BASE PAGE_OFFSET-1 Permanent kernel mappings + One way of mapping HIGHMEM pages into kernel + space. + +MODULES_VADDR MODULES_END-1 Kernel module space Kernel modules inserted via insmod are placed here using dynamic mappings. diff --git a/Documentation/arm/msm/gpiomux.txt b/Documentation/arm/msm/gpiomux.txt new file mode 100644 index 00000000000..67a81620adf --- /dev/null +++ b/Documentation/arm/msm/gpiomux.txt @@ -0,0 +1,176 @@ +This document provides an overview of the msm_gpiomux interface, which +is used to provide gpio pin multiplexing and configuration on mach-msm +targets. + +History +======= + +The first-generation API for gpio configuration & multiplexing on msm +is the function gpio_tlmm_config(). This function has a few notable +shortcomings, which led to its deprecation and replacement by gpiomux: + +The 'disable' parameter: Setting the second parameter to +gpio_tlmm_config to GPIO_CFG_DISABLE tells the peripheral +processor in charge of the subsystem to perform a look-up into a +low-power table and apply the low-power/sleep setting for the pin. +As the msm family evolved this became problematic. Not all pins +have sleep settings, not all peripheral processors will accept requests +to apply said sleep settings, and not all msm targets have their gpio +subsystems managed by a peripheral processor. In order to get consistent +behavior on all targets, drivers are forced to ignore this parameter, +rendering it useless. + +The 'direction' flag: for all mux-settings other than raw-gpio (0), +the output-enable bit of a gpio is hard-wired to a known +input (usually VDD or ground). For those settings, the direction flag +is meaningless at best, and deceptive at worst. In addition, using the +direction flag to change output-enable (OE) directly can cause trouble in +gpiolib, which has no visibility into gpio direction changes made +in this way. Direction control in gpio mode should be made through gpiolib. + +Key Features of gpiomux +======================= + +- A consistent interface across all generations of msm. Drivers can expect +the same results on every target. +- gpiomux plays nicely with gpiolib. Functions that should belong to gpiolib +are left to gpiolib and not duplicated here. gpiomux is written with the +intent that gpio_chips will call gpiomux reference-counting methods +from their request() and free() hooks, providing full integration. +- Tabular configuration. Instead of having to call gpio_tlmm_config +hundreds of times, gpio configuration is placed in a single table. +- Per-gpio sleep. Each gpio is individually reference counted, allowing only +those lines which are in use to be put in high-power states. +- 0 means 'do nothing': all flags are designed so that the default memset-zero +equates to a sensible default of 'no configuration', preventing users +from having to provide hundreds of 'no-op' configs for unused or +unwanted lines. + +Usage +===== + +To use gpiomux, provide configuration information for relevant gpio lines +in the msm_gpiomux_configs table. Since a 0 equates to "unconfigured", +only those lines to be managed by gpiomux need to be specified. Here +is a completely fictional example: + +struct msm_gpiomux_config msm_gpiomux_configs[GPIOMUX_NGPIOS] = { + [12] = { + .active = GPIOMUX_VALID | GPIOMUX_DRV_8MA | GPIOMUX_FUNC_1, + .suspended = GPIOMUX_VALID | GPIOMUX_PULL_DOWN, + }, + [34] = { + .suspended = GPIOMUX_VALID | GPIOMUX_PULL_DOWN, + }, +}; + +To indicate that a gpio is in use, call msm_gpiomux_get() to increase +its reference count. To decrease the reference count, call msm_gpiomux_put(). + +The effect of this configuration is as follows: + +When the system boots, gpios 12 and 34 will be initialized with their +'suspended' configurations. All other gpios, which were left unconfigured, +will not be touched. + +When msm_gpiomux_get() is called on gpio 12 to raise its reference count +above 0, its active configuration will be applied. Since no other gpio +line has a valid active configuration, msm_gpiomux_get() will have no +effect on any other line. + +When msm_gpiomux_put() is called on gpio 12 or 34 to drop their reference +count to 0, their suspended configurations will be applied. +Since no other gpio line has a valid suspended configuration, no other +gpio line will be effected by msm_gpiomux_put(). Since gpio 34 has no valid +active configuration, this is effectively a no-op for gpio 34 as well, +with one small caveat, see the section "About Output-Enable Settings". + +All of the GPIOMUX_VALID flags may seem like unnecessary overhead, but +they address some important issues. As unused entries (all those +except 12 and 34) are zero-filled, gpiomux needs a way to distinguish +the used fields from the unused. In addition, the all-zero pattern +is a valid configuration! Therefore, gpiomux defines an additional bit +which is used to indicate when a field is used. This has the pleasant +side-effect of allowing calls to msm_gpiomux_write to use '0' to indicate +that a value should not be changed: + + msm_gpiomux_write(0, GPIOMUX_VALID, 0); + +replaces the active configuration of gpio 0 with an all-zero configuration, +but leaves the suspended configuration as it was. + +Static Configurations +===================== + +To install a static configuration, which is applied at boot and does +not change after that, install a configuration with a suspended component +but no active component, as in the previous example: + + [34] = { + .suspended = GPIOMUX_VALID | GPIOMUX_PULL_DOWN, + }, + +The suspended setting is applied during boot, and the lack of any valid +active setting prevents any other setting from being applied at runtime. +If other subsystems attempting to access the line is a concern, one could +*really* anchor the configuration down by calling msm_gpiomux_get on the +line at initialization to move the line into active mode. With the line +held, it will never be re-suspended, and with no valid active configuration, +no new configurations will be applied. + +But then, if having other subsystems grabbing for the line is truly a concern, +it should be reserved with gpio_request instead, which carries an implicit +msm_gpiomux_get. + +gpiomux and gpiolib +=================== + +It is expected that msm gpio_chips will call msm_gpiomux_get() and +msm_gpiomux_put() from their request and free hooks, like this fictional +example: + +static int request(struct gpio_chip *chip, unsigned offset) +{ + return msm_gpiomux_get(chip->base + offset); +} + +static void free(struct gpio_chip *chip, unsigned offset) +{ + msm_gpiomux_put(chip->base + offset); +} + + ...somewhere in a gpio_chip declaration... + .request = request, + .free = free, + +This provides important functionality: +- It guarantees that a gpio line will have its 'active' config applied + when the line is requested, and will not be suspended while the line + remains requested; and +- It guarantees that gpio-direction settings from gpiolib behave sensibly. + See "About Output-Enable Settings." + +This mechanism allows for "auto-request" of gpiomux lines via gpiolib +when it is suitable. Drivers wishing more exact control are, of course, +free to also use msm_gpiomux_set and msm_gpiomux_get. + +About Output-Enable Settings +============================ + +Some msm targets do not have the ability to query the current gpio +configuration setting. This means that changes made to the output-enable +(OE) bit by gpiolib cannot be consistently detected and preserved by gpiomux. +Therefore, when gpiomux applies a configuration setting, any direction +settings which may have been applied by gpiolib are lost and the default +input settings are re-applied. + +For this reason, drivers should not assume that gpio direction settings +continue to hold if they free and then re-request a gpio. This seems like +common sense - after all, anybody could have obtained the line in the +meantime - but it needs saying. + +This also means that calls to msm_gpiomux_write will reset the OE bit, +which means that if the gpio line is held by a client of gpiolib and +msm_gpiomux_write is called, the direction setting has been lost and +gpiolib's internal state has been broken. +Release gpio lines before reconfiguring them. diff --git a/Documentation/arm/pxa/mfp.txt b/Documentation/arm/pxa/mfp.txt new file mode 100644 index 00000000000..a179e5bc02c --- /dev/null +++ b/Documentation/arm/pxa/mfp.txt @@ -0,0 +1,286 @@ + MFP Configuration for PXA2xx/PXA3xx Processors + + Eric Miao <eric.miao@marvell.com> + +MFP stands for Multi-Function Pin, which is the pin-mux logic on PXA3xx and +later PXA series processors. This document describes the existing MFP API, +and how board/platform driver authors could make use of it. + + Basic Concept +=============== + +Unlike the GPIO alternate function settings on PXA25x and PXA27x, a new MFP +mechanism is introduced from PXA3xx to completely move the pin-mux functions +out of the GPIO controller. In addition to pin-mux configurations, the MFP +also controls the low power state, driving strength, pull-up/down and event +detection of each pin. Below is a diagram of internal connections between +the MFP logic and the remaining SoC peripherals: + + +--------+ + | |--(GPIO19)--+ + | GPIO | | + | |--(GPIO...) | + +--------+ | + | +---------+ + +--------+ +------>| | + | PWM2 |--(PWM_OUT)-------->| MFP | + +--------+ +------>| |-------> to external PAD + | +---->| | + +--------+ | | +-->| | + | SSP2 |---(TXD)----+ | | +---------+ + +--------+ | | + | | + +--------+ | | + | Keypad |--(MKOUT4)----+ | + +--------+ | + | + +--------+ | + | UART2 |---(TXD)--------+ + +--------+ + +NOTE: the external pad is named as MFP_PIN_GPIO19, it doesn't necessarily +mean it's dedicated for GPIO19, only as a hint that internally this pin +can be routed from GPIO19 of the GPIO controller. + +To better understand the change from PXA25x/PXA27x GPIO alternate function +to this new MFP mechanism, here are several key points: + + 1. GPIO controller on PXA3xx is now a dedicated controller, same as other + internal controllers like PWM, SSP and UART, with 128 internal signals + which can be routed to external through one or more MFPs (e.g. GPIO<0> + can be routed through either MFP_PIN_GPIO0 as well as MFP_PIN_GPIO0_2, + see arch/arm/mach-pxa/mach/include/mfp-pxa300.h) + + 2. Alternate function configuration is removed from this GPIO controller, + the remaining functions are pure GPIO-specific, i.e. + + - GPIO signal level control + - GPIO direction control + - GPIO level change detection + + 3. Low power state for each pin is now controlled by MFP, this means the + PGSRx registers on PXA2xx are now useless on PXA3xx + + 4. Wakeup detection is now controlled by MFP, PWER does not control the + wakeup from GPIO(s) any more, depending on the sleeping state, ADxER + (as defined in pxa3xx-regs.h) controls the wakeup from MFP + +NOTE: with such a clear separation of MFP and GPIO, by GPIO<xx> we normally +mean it is a GPIO signal, and by MFP<xxx> or pin xxx, we mean a physical +pad (or ball). + + MFP API Usage +=============== + +For board code writers, here are some guidelines: + +1. include ONE of the following header files in your <board>.c: + + - #include <mach/mfp-pxa25x.h> + - #include <mach/mfp-pxa27x.h> + - #include <mach/mfp-pxa300.h> + - #include <mach/mfp-pxa320.h> + - #include <mach/mfp-pxa930.h> + + NOTE: only one file in your <board>.c, depending on the processors used, + because pin configuration definitions may conflict in these file (i.e. + same name, different meaning and settings on different processors). E.g. + for zylonite platform, which support both PXA300/PXA310 and PXA320, two + separate files are introduced: zylonite_pxa300.c and zylonite_pxa320.c + (in addition to handle MFP configuration differences, they also handle + the other differences between the two combinations). + + NOTE: PXA300 and PXA310 are almost identical in pin configurations (with + PXA310 supporting some additional ones), thus the difference is actually + covered in a single mfp-pxa300.h. + +2. prepare an array for the initial pin configurations, e.g.: + + static unsigned long mainstone_pin_config[] __initdata = { + /* Chip Select */ + GPIO15_nCS_1, + + /* LCD - 16bpp Active TFT */ + GPIOxx_TFT_LCD_16BPP, + GPIO16_PWM0_OUT, /* Backlight */ + + /* MMC */ + GPIO32_MMC_CLK, + GPIO112_MMC_CMD, + GPIO92_MMC_DAT_0, + GPIO109_MMC_DAT_1, + GPIO110_MMC_DAT_2, + GPIO111_MMC_DAT_3, + + ... + + /* GPIO */ + GPIO1_GPIO | WAKEUP_ON_EDGE_BOTH, + }; + + a) once the pin configurations are passed to pxa{2xx,3xx}_mfp_config(), + and written to the actual registers, they are useless and may discard, + adding '__initdata' will help save some additional bytes here. + + b) when there is only one possible pin configurations for a component, + some simplified definitions can be used, e.g. GPIOxx_TFT_LCD_16BPP on + PXA25x and PXA27x processors + + c) if by board design, a pin can be configured to wake up the system + from low power state, it can be 'OR'ed with any of: + + WAKEUP_ON_EDGE_BOTH + WAKEUP_ON_EDGE_RISE + WAKEUP_ON_EDGE_FALL + WAKEUP_ON_LEVEL_HIGH - specifically for enabling of keypad GPIOs, + + to indicate that this pin has the capability of wake-up the system, + and on which edge(s). This, however, doesn't necessarily mean the + pin _will_ wakeup the system, it will only when set_irq_wake() is + invoked with the corresponding GPIO IRQ (GPIO_IRQ(xx) or gpio_to_irq()) + and eventually calls gpio_set_wake() for the actual register setting. + + d) although PXA3xx MFP supports edge detection on each pin, the + internal logic will only wakeup the system when those specific bits + in ADxER registers are set, which can be well mapped to the + corresponding peripheral, thus set_irq_wake() can be called with + the peripheral IRQ to enable the wakeup. + + + MFP on PXA3xx +=============== + +Every external I/O pad on PXA3xx (excluding those for special purpose) has +one MFP logic associated, and is controlled by one MFP register (MFPR). + +The MFPR has the following bit definitions (for PXA300/PXA310/PXA320): + + 31 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 + +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + | RESERVED |PS|PU|PD| DRIVE |SS|SD|SO|EC|EF|ER|--| AF_SEL | + +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+ + + Bit 3: RESERVED + Bit 4: EDGE_RISE_EN - enable detection of rising edge on this pin + Bit 5: EDGE_FALL_EN - enable detection of falling edge on this pin + Bit 6: EDGE_CLEAR - disable edge detection on this pin + Bit 7: SLEEP_OE_N - enable outputs during low power modes + Bit 8: SLEEP_DATA - output data on the pin during low power modes + Bit 9: SLEEP_SEL - selection control for low power modes signals + Bit 13: PULLDOWN_EN - enable the internal pull-down resistor on this pin + Bit 14: PULLUP_EN - enable the internal pull-up resistor on this pin + Bit 15: PULL_SEL - pull state controlled by selected alternate function + (0) or by PULL{UP,DOWN}_EN bits (1) + + Bit 0 - 2: AF_SEL - alternate function selection, 8 possibilities, from 0-7 + Bit 10-12: DRIVE - drive strength and slew rate + 0b000 - fast 1mA + 0b001 - fast 2mA + 0b002 - fast 3mA + 0b003 - fast 4mA + 0b004 - slow 6mA + 0b005 - fast 6mA + 0b006 - slow 10mA + 0b007 - fast 10mA + + MFP Design for PXA2xx/PXA3xx +============================== + +Due to the difference of pin-mux handling between PXA2xx and PXA3xx, a unified +MFP API is introduced to cover both series of processors. + +The basic idea of this design is to introduce definitions for all possible pin +configurations, these definitions are processor and platform independent, and +the actual API invoked to convert these definitions into register settings and +make them effective there-after. + + Files Involved + -------------- + + - arch/arm/mach-pxa/include/mach/mfp.h + + for + 1. Unified pin definitions - enum constants for all configurable pins + 2. processor-neutral bit definitions for a possible MFP configuration + + - arch/arm/mach-pxa/include/mach/mfp-pxa3xx.h + + for PXA3xx specific MFPR register bit definitions and PXA3xx common pin + configurations + + - arch/arm/mach-pxa/include/mach/mfp-pxa2xx.h + + for PXA2xx specific definitions and PXA25x/PXA27x common pin configurations + + - arch/arm/mach-pxa/include/mach/mfp-pxa25x.h + arch/arm/mach-pxa/include/mach/mfp-pxa27x.h + arch/arm/mach-pxa/include/mach/mfp-pxa300.h + arch/arm/mach-pxa/include/mach/mfp-pxa320.h + arch/arm/mach-pxa/include/mach/mfp-pxa930.h + + for processor specific definitions + + - arch/arm/mach-pxa/mfp-pxa3xx.c + - arch/arm/mach-pxa/mfp-pxa2xx.c + + for implementation of the pin configuration to take effect for the actual + processor. + + Pin Configuration + ----------------- + + The following comments are copied from mfp.h (see the actual source code + for most updated info) + + /* + * a possible MFP configuration is represented by a 32-bit integer + * + * bit 0.. 9 - MFP Pin Number (1024 Pins Maximum) + * bit 10..12 - Alternate Function Selection + * bit 13..15 - Drive Strength + * bit 16..18 - Low Power Mode State + * bit 19..20 - Low Power Mode Edge Detection + * bit 21..22 - Run Mode Pull State + * + * to facilitate the definition, the following macros are provided + * + * MFP_CFG_DEFAULT - default MFP configuration value, with + * alternate function = 0, + * drive strength = fast 3mA (MFP_DS03X) + * low power mode = default + * edge detection = none + * + * MFP_CFG - default MFPR value with alternate function + * MFP_CFG_DRV - default MFPR value with alternate function and + * pin drive strength + * MFP_CFG_LPM - default MFPR value with alternate function and + * low power mode + * MFP_CFG_X - default MFPR value with alternate function, + * pin drive strength and low power mode + */ + + Examples of pin configurations are: + + #define GPIO94_SSP3_RXD MFP_CFG_X(GPIO94, AF1, DS08X, FLOAT) + + which reads GPIO94 can be configured as SSP3_RXD, with alternate function + selection of 1, driving strength of 0b101, and a float state in low power + modes. + + NOTE: this is the default setting of this pin being configured as SSP3_RXD + which can be modified a bit in board code, though it is not recommended to + do so, simply because this default setting is usually carefully encoded, + and is supposed to work in most cases. + + Register Settings + ----------------- + + Register settings on PXA3xx for a pin configuration is actually very + straight-forward, most bits can be converted directly into MFPR value + in a easier way. Two sets of MFPR values are calculated: the run-time + ones and the low power mode ones, to allow different settings. + + The conversion from a generic pin configuration to the actual register + settings on PXA2xx is a bit complicated: many registers are involved, + including GAFRx, GPDRx, PGSRx, PWER, PKWR, PFER and PRER. Please see + mfp-pxa2xx.c for how the conversion is made. diff --git a/Documentation/arm/sti/overview.txt b/Documentation/arm/sti/overview.txt new file mode 100644 index 00000000000..1a4e93d6027 --- /dev/null +++ b/Documentation/arm/sti/overview.txt @@ -0,0 +1,33 @@ + STi ARM Linux Overview + ========================== + +Introduction +------------ + + The ST Microelectronics Multimedia and Application Processors range of + CortexA9 System-on-Chip are supported by the 'STi' platform of + ARM Linux. Currently STiH415, STiH416 SOCs are supported with both + B2000 and B2020 Reference boards. + + + configuration + ------------- + + A generic configuration is provided for both STiH415/416, and can be used as the + default by + make stih41x_defconfig + + Layout + ------ + All the files for multiple machine families (STiH415, STiH416, and STiG125) + are located in the platform code contained in arch/arm/mach-sti + + There is a generic board board-dt.c in the mach folder which support + Flattened Device Tree, which means, It works with any compatible board with + Device Trees. + + + Document Author + --------------- + + Srinivas Kandagatla <srinivas.kandagatla@st.com>, (c) 2013 ST Microelectronics diff --git a/Documentation/arm/sti/stih407-overview.txt b/Documentation/arm/sti/stih407-overview.txt new file mode 100644 index 00000000000..3343f32f58b --- /dev/null +++ b/Documentation/arm/sti/stih407-overview.txt @@ -0,0 +1,18 @@ + STiH407 Overview + ================ + +Introduction +------------ + + The STiH407 is the new generation of SoC for Multi-HD, AVC set-top boxes + and server/connected client application for satellite, cable, terrestrial + and IP-STB markets. + + Features + - ARM Cortex-A9 1.5 GHz dual core CPU (28nm) + - SATA2, USB 3.0, PCIe, Gbit Ethernet + + Document Author + --------------- + + Maxime Coquelin <maxime.coquelin@st.com>, (c) 2014 ST Microelectronics diff --git a/Documentation/arm/sti/stih415-overview.txt b/Documentation/arm/sti/stih415-overview.txt new file mode 100644 index 00000000000..1383e33f265 --- /dev/null +++ b/Documentation/arm/sti/stih415-overview.txt @@ -0,0 +1,12 @@ + STiH415 Overview + ================ + +Introduction +------------ + + The STiH415 is the next generation of HD, AVC set-top box processors + for satellite, cable, terrestrial and IP-STB markets. + + Features + - ARM Cortex-A9 1.0 GHz, dual-core CPU + - SATA2x2,USB 2.0x3, PCIe, Gbit Ethernet MACx2 diff --git a/Documentation/arm/sti/stih416-overview.txt b/Documentation/arm/sti/stih416-overview.txt new file mode 100644 index 00000000000..558444c201c --- /dev/null +++ b/Documentation/arm/sti/stih416-overview.txt @@ -0,0 +1,12 @@ + STiH416 Overview + ================ + +Introduction +------------ + + The STiH416 is the next generation of HD, AVC set-top box processors + for satellite, cable, terrestrial and IP-STB markets. + + Features + - ARM Cortex-A9 1.2 GHz dual core CPU + - SATA2x2,USB 2.0x3, PCIe, Gbit Ethernet MACx2 diff --git a/Documentation/arm/sunxi/README b/Documentation/arm/sunxi/README new file mode 100644 index 00000000000..7945238453e --- /dev/null +++ b/Documentation/arm/sunxi/README @@ -0,0 +1,52 @@ +ARM Allwinner SoCs +================== + +This document lists all the ARM Allwinner SoCs that are currently +supported in mainline by the Linux kernel. This document will also +provide links to documentation and/or datasheet for these SoCs. + +SunXi family +------------ + Linux kernel mach directory: arch/arm/mach-sunxi + + Flavors: + * ARM926 based SoCs + - Allwinner F20 (sun3i) + + Not Supported + + * ARM Cortex-A8 based SoCs + - Allwinner A10 (sun4i) + + Datasheet + http://dl.linux-sunxi.org/A10/A10%20Datasheet%20-%20v1.21%20%282012-04-06%29.pdf + + User Manual + http://dl.linux-sunxi.org/A10/A10%20User%20Manual%20-%20v1.20%20%282012-04-09%2c%20DECRYPTED%29.pdf + + - Allwinner A10s (sun5i) + + Datasheet + http://dl.linux-sunxi.org/A10s/A10s%20Datasheet%20-%20v1.20%20%282012-03-27%29.pdf + + - Allwinner A13 (sun5i) + + Datasheet + http://dl.linux-sunxi.org/A13/A13%20Datasheet%20-%20v1.12%20%282012-03-29%29.pdf + + User Manual + http://dl.linux-sunxi.org/A13/A13%20User%20Manual%20-%20v1.2%20%282013-01-08%29.pdf + + * Dual ARM Cortex-A7 based SoCs + - Allwinner A20 (sun7i) + + User Manual + http://dl.linux-sunxi.org/A20/A20%20User%20Manual%202013-03-22.pdf + + - Allwinner A23 + + Not Supported + + * Quad ARM Cortex-A7 based SoCs + - Allwinner A31 (sun6i) + + Datasheet + http://dl.linux-sunxi.org/A31/A31%20Datasheet%20-%20v1.00%20(2012-12-24).pdf + + - Allwinner A31s (sun6i) + + Not Supported + + * Quad ARM Cortex-A15, Quad ARM Cortex-A7 based SoCs + - Allwinner A80 + + Not Supported
\ No newline at end of file diff --git a/Documentation/arm/sunxi/clocks.txt b/Documentation/arm/sunxi/clocks.txt new file mode 100644 index 00000000000..e09a88aa313 --- /dev/null +++ b/Documentation/arm/sunxi/clocks.txt @@ -0,0 +1,56 @@ +Frequently asked questions about the sunxi clock system +======================================================= + +This document contains useful bits of information that people tend to ask +about the sunxi clock system, as well as accompanying ASCII art when adequate. + +Q: Why is the main 24MHz oscillator gatable? Wouldn't that break the + system? + +A: The 24MHz oscillator allows gating to save power. Indeed, if gated + carelessly the system would stop functioning, but with the right + steps, one can gate it and keep the system running. Consider this + simplified suspend example: + + While the system is operational, you would see something like + + 24MHz 32kHz + | + PLL1 + \ + \_ CPU Mux + | + [CPU] + + When you are about to suspend, you switch the CPU Mux to the 32kHz + oscillator: + + 24Mhz 32kHz + | | + PLL1 | + / + CPU Mux _/ + | + [CPU] + + Finally you can gate the main oscillator + + 32kHz + | + | + / + CPU Mux _/ + | + [CPU] + +Q: Were can I learn more about the sunxi clocks? + +A: The linux-sunxi wiki contains a page documenting the clock registers, + you can find it at + + http://linux-sunxi.org/A10/CCM + + The authoritative source for information at this time is the ccmu driver + released by Allwinner, you can find it at + + https://github.com/linux-sunxi/linux-sunxi/tree/sunxi-3.0/arch/arm/mach-sun4i/clock/ccmu diff --git a/Documentation/arm/swp_emulation b/Documentation/arm/swp_emulation new file mode 100644 index 00000000000..af903d22fd9 --- /dev/null +++ b/Documentation/arm/swp_emulation @@ -0,0 +1,27 @@ +Software emulation of deprecated SWP instruction (CONFIG_SWP_EMULATE) +--------------------------------------------------------------------- + +ARMv6 architecture deprecates use of the SWP/SWPB instructions, and recommeds +moving to the load-locked/store-conditional instructions LDREX and STREX. + +ARMv7 multiprocessing extensions introduce the ability to disable these +instructions, triggering an undefined instruction exception when executed. +Trapped instructions are emulated using an LDREX/STREX or LDREXB/STREXB +sequence. If a memory access fault (an abort) occurs, a segmentation fault is +signalled to the triggering process. + +/proc/cpu/swp_emulation holds some statistics/information, including the PID of +the last process to trigger the emulation to be invocated. For example: +--- +Emulated SWP: 12 +Emulated SWPB: 0 +Aborted SWP{B}: 1 +Last process: 314 +--- + +NOTE: when accessing uncached shared regions, LDREX/STREX rely on an external +transaction monitoring block called a global monitor to maintain update +atomicity. If your system does not implement a global monitor, this option can +cause programs that perform SWP operations to uncached memory to deadlock, as +the STREX operation will always fail. + diff --git a/Documentation/arm/tcm.txt b/Documentation/arm/tcm.txt new file mode 100644 index 00000000000..7c15871c188 --- /dev/null +++ b/Documentation/arm/tcm.txt @@ -0,0 +1,155 @@ +ARM TCM (Tightly-Coupled Memory) handling in Linux +---- +Written by Linus Walleij <linus.walleij@stericsson.com> + +Some ARM SoC:s have a so-called TCM (Tightly-Coupled Memory). +This is usually just a few (4-64) KiB of RAM inside the ARM +processor. + +Due to being embedded inside the CPU The TCM has a +Harvard-architecture, so there is an ITCM (instruction TCM) +and a DTCM (data TCM). The DTCM can not contain any +instructions, but the ITCM can actually contain data. +The size of DTCM or ITCM is minimum 4KiB so the typical +minimum configuration is 4KiB ITCM and 4KiB DTCM. + +ARM CPU:s have special registers to read out status, physical +location and size of TCM memories. arch/arm/include/asm/cputype.h +defines a CPUID_TCM register that you can read out from the +system control coprocessor. Documentation from ARM can be found +at http://infocenter.arm.com, search for "TCM Status Register" +to see documents for all CPUs. Reading this register you can +determine if ITCM (bits 1-0) and/or DTCM (bit 17-16) is present +in the machine. + +There is further a TCM region register (search for "TCM Region +Registers" at the ARM site) that can report and modify the location +size of TCM memories at runtime. This is used to read out and modify +TCM location and size. Notice that this is not a MMU table: you +actually move the physical location of the TCM around. At the +place you put it, it will mask any underlying RAM from the +CPU so it is usually wise not to overlap any physical RAM with +the TCM. + +The TCM memory can then be remapped to another address again using +the MMU, but notice that the TCM if often used in situations where +the MMU is turned off. To avoid confusion the current Linux +implementation will map the TCM 1 to 1 from physical to virtual +memory in the location specified by the kernel. Currently Linux +will map ITCM to 0xfffe0000 and on, and DTCM to 0xfffe8000 and +on, supporting a maximum of 32KiB of ITCM and 32KiB of DTCM. + +Newer versions of the region registers also support dividing these +TCMs in two separate banks, so for example an 8KiB ITCM is divided +into two 4KiB banks with its own control registers. The idea is to +be able to lock and hide one of the banks for use by the secure +world (TrustZone). + +TCM is used for a few things: + +- FIQ and other interrupt handlers that need deterministic + timing and cannot wait for cache misses. + +- Idle loops where all external RAM is set to self-refresh + retention mode, so only on-chip RAM is accessible by + the CPU and then we hang inside ITCM waiting for an + interrupt. + +- Other operations which implies shutting off or reconfiguring + the external RAM controller. + +There is an interface for using TCM on the ARM architecture +in <asm/tcm.h>. Using this interface it is possible to: + +- Define the physical address and size of ITCM and DTCM. + +- Tag functions to be compiled into ITCM. + +- Tag data and constants to be allocated to DTCM and ITCM. + +- Have the remaining TCM RAM added to a special + allocation pool with gen_pool_create() and gen_pool_add() + and provice tcm_alloc() and tcm_free() for this + memory. Such a heap is great for things like saving + device state when shutting off device power domains. + +A machine that has TCM memory shall select HAVE_TCM from +arch/arm/Kconfig for itself. Code that needs to use TCM shall +#include <asm/tcm.h> + +Functions to go into itcm can be tagged like this: +int __tcmfunc foo(int bar); + +Since these are marked to become long_calls and you may want +to have functions called locally inside the TCM without +wasting space, there is also the __tcmlocalfunc prefix that +will make the call relative. + +Variables to go into dtcm can be tagged like this: +int __tcmdata foo; + +Constants can be tagged like this: +int __tcmconst foo; + +To put assembler into TCM just use +.section ".tcm.text" or .section ".tcm.data" +respectively. + +Example code: + +#include <asm/tcm.h> + +/* Uninitialized data */ +static u32 __tcmdata tcmvar; +/* Initialized data */ +static u32 __tcmdata tcmassigned = 0x2BADBABEU; +/* Constant */ +static const u32 __tcmconst tcmconst = 0xCAFEBABEU; + +static void __tcmlocalfunc tcm_to_tcm(void) +{ + int i; + for (i = 0; i < 100; i++) + tcmvar ++; +} + +static void __tcmfunc hello_tcm(void) +{ + /* Some abstract code that runs in ITCM */ + int i; + for (i = 0; i < 100; i++) { + tcmvar ++; + } + tcm_to_tcm(); +} + +static void __init test_tcm(void) +{ + u32 *tcmem; + int i; + + hello_tcm(); + printk("Hello TCM executed from ITCM RAM\n"); + + printk("TCM variable from testrun: %u @ %p\n", tcmvar, &tcmvar); + tcmvar = 0xDEADBEEFU; + printk("TCM variable: 0x%x @ %p\n", tcmvar, &tcmvar); + + printk("TCM assigned variable: 0x%x @ %p\n", tcmassigned, &tcmassigned); + + printk("TCM constant: 0x%x @ %p\n", tcmconst, &tcmconst); + + /* Allocate some TCM memory from the pool */ + tcmem = tcm_alloc(20); + if (tcmem) { + printk("TCM Allocated 20 bytes of TCM @ %p\n", tcmem); + tcmem[0] = 0xDEADBEEFU; + tcmem[1] = 0x2BADBABEU; + tcmem[2] = 0xCAFEBABEU; + tcmem[3] = 0xDEADBEEFU; + tcmem[4] = 0x2BADBABEU; + for (i = 0; i < 5; i++) + printk("TCM tcmem[%d] = %08x\n", i, tcmem[i]); + tcm_free(tcmem, 20); + } +} diff --git a/Documentation/arm/uefi.txt b/Documentation/arm/uefi.txt new file mode 100644 index 00000000000..d60030a1b90 --- /dev/null +++ b/Documentation/arm/uefi.txt @@ -0,0 +1,64 @@ +UEFI, the Unified Extensible Firmware Interface, is a specification +governing the behaviours of compatible firmware interfaces. It is +maintained by the UEFI Forum - http://www.uefi.org/. + +UEFI is an evolution of its predecessor 'EFI', so the terms EFI and +UEFI are used somewhat interchangeably in this document and associated +source code. As a rule, anything new uses 'UEFI', whereas 'EFI' refers +to legacy code or specifications. + +UEFI support in Linux +===================== +Booting on a platform with firmware compliant with the UEFI specification +makes it possible for the kernel to support additional features: +- UEFI Runtime Services +- Retrieving various configuration information through the standardised + interface of UEFI configuration tables. (ACPI, SMBIOS, ...) + +For actually enabling [U]EFI support, enable: +- CONFIG_EFI=y +- CONFIG_EFI_VARS=y or m + +The implementation depends on receiving information about the UEFI environment +in a Flattened Device Tree (FDT) - so is only available with CONFIG_OF. + +UEFI stub +========= +The "stub" is a feature that extends the Image/zImage into a valid UEFI +PE/COFF executable, including a loader application that makes it possible to +load the kernel directly from the UEFI shell, boot menu, or one of the +lightweight bootloaders like Gummiboot or rEFInd. + +The kernel image built with stub support remains a valid kernel image for +booting in non-UEFI environments. + +UEFI kernel support on ARM +========================== +UEFI kernel support on the ARM architectures (arm and arm64) is only available +when boot is performed through the stub. + +When booting in UEFI mode, the stub deletes any memory nodes from a provided DT. +Instead, the kernel reads the UEFI memory map. + +The stub populates the FDT /chosen node with (and the kernel scans for) the +following parameters: +________________________________________________________________________________ +Name | Size | Description +================================================================================ +linux,uefi-system-table | 64-bit | Physical address of the UEFI System Table. +-------------------------------------------------------------------------------- +linux,uefi-mmap-start | 64-bit | Physical address of the UEFI memory map, + | | populated by the UEFI GetMemoryMap() call. +-------------------------------------------------------------------------------- +linux,uefi-mmap-size | 32-bit | Size in bytes of the UEFI memory map + | | pointed to in previous entry. +-------------------------------------------------------------------------------- +linux,uefi-mmap-desc-size | 32-bit | Size in bytes of each entry in the UEFI + | | memory map. +-------------------------------------------------------------------------------- +linux,uefi-mmap-desc-ver | 32-bit | Version of the mmap descriptor format. +-------------------------------------------------------------------------------- +linux,uefi-stub-kern-ver | string | Copy of linux_banner from build. +-------------------------------------------------------------------------------- + +For verbose debug messages, specify 'uefi_debug' on the kernel command line. diff --git a/Documentation/arm/vlocks.txt b/Documentation/arm/vlocks.txt new file mode 100644 index 00000000000..415960a9bab --- /dev/null +++ b/Documentation/arm/vlocks.txt @@ -0,0 +1,211 @@ +vlocks for Bare-Metal Mutual Exclusion +====================================== + +Voting Locks, or "vlocks" provide a simple low-level mutual exclusion +mechanism, with reasonable but minimal requirements on the memory +system. + +These are intended to be used to coordinate critical activity among CPUs +which are otherwise non-coherent, in situations where the hardware +provides no other mechanism to support this and ordinary spinlocks +cannot be used. + + +vlocks make use of the atomicity provided by the memory system for +writes to a single memory location. To arbitrate, every CPU "votes for +itself", by storing a unique number to a common memory location. The +final value seen in that memory location when all the votes have been +cast identifies the winner. + +In order to make sure that the election produces an unambiguous result +in finite time, a CPU will only enter the election in the first place if +no winner has been chosen and the election does not appear to have +started yet. + + +Algorithm +--------- + +The easiest way to explain the vlocks algorithm is with some pseudo-code: + + + int currently_voting[NR_CPUS] = { 0, }; + int last_vote = -1; /* no votes yet */ + + bool vlock_trylock(int this_cpu) + { + /* signal our desire to vote */ + currently_voting[this_cpu] = 1; + if (last_vote != -1) { + /* someone already volunteered himself */ + currently_voting[this_cpu] = 0; + return false; /* not ourself */ + } + + /* let's suggest ourself */ + last_vote = this_cpu; + currently_voting[this_cpu] = 0; + + /* then wait until everyone else is done voting */ + for_each_cpu(i) { + while (currently_voting[i] != 0) + /* wait */; + } + + /* result */ + if (last_vote == this_cpu) + return true; /* we won */ + return false; + } + + bool vlock_unlock(void) + { + last_vote = -1; + } + + +The currently_voting[] array provides a way for the CPUs to determine +whether an election is in progress, and plays a role analogous to the +"entering" array in Lamport's bakery algorithm [1]. + +However, once the election has started, the underlying memory system +atomicity is used to pick the winner. This avoids the need for a static +priority rule to act as a tie-breaker, or any counters which could +overflow. + +As long as the last_vote variable is globally visible to all CPUs, it +will contain only one value that won't change once every CPU has cleared +its currently_voting flag. + + +Features and limitations +------------------------ + + * vlocks are not intended to be fair. In the contended case, it is the + _last_ CPU which attempts to get the lock which will be most likely + to win. + + vlocks are therefore best suited to situations where it is necessary + to pick a unique winner, but it does not matter which CPU actually + wins. + + * Like other similar mechanisms, vlocks will not scale well to a large + number of CPUs. + + vlocks can be cascaded in a voting hierarchy to permit better scaling + if necessary, as in the following hypothetical example for 4096 CPUs: + + /* first level: local election */ + my_town = towns[(this_cpu >> 4) & 0xf]; + I_won = vlock_trylock(my_town, this_cpu & 0xf); + if (I_won) { + /* we won the town election, let's go for the state */ + my_state = states[(this_cpu >> 8) & 0xf]; + I_won = vlock_lock(my_state, this_cpu & 0xf)); + if (I_won) { + /* and so on */ + I_won = vlock_lock(the_whole_country, this_cpu & 0xf]; + if (I_won) { + /* ... */ + } + vlock_unlock(the_whole_country); + } + vlock_unlock(my_state); + } + vlock_unlock(my_town); + + +ARM implementation +------------------ + +The current ARM implementation [2] contains some optimisations beyond +the basic algorithm: + + * By packing the members of the currently_voting array close together, + we can read the whole array in one transaction (providing the number + of CPUs potentially contending the lock is small enough). This + reduces the number of round-trips required to external memory. + + In the ARM implementation, this means that we can use a single load + and comparison: + + LDR Rt, [Rn] + CMP Rt, #0 + + ...in place of code equivalent to: + + LDRB Rt, [Rn] + CMP Rt, #0 + LDRBEQ Rt, [Rn, #1] + CMPEQ Rt, #0 + LDRBEQ Rt, [Rn, #2] + CMPEQ Rt, #0 + LDRBEQ Rt, [Rn, #3] + CMPEQ Rt, #0 + + This cuts down on the fast-path latency, as well as potentially + reducing bus contention in contended cases. + + The optimisation relies on the fact that the ARM memory system + guarantees coherency between overlapping memory accesses of + different sizes, similarly to many other architectures. Note that + we do not care which element of currently_voting appears in which + bits of Rt, so there is no need to worry about endianness in this + optimisation. + + If there are too many CPUs to read the currently_voting array in + one transaction then multiple transations are still required. The + implementation uses a simple loop of word-sized loads for this + case. The number of transactions is still fewer than would be + required if bytes were loaded individually. + + + In principle, we could aggregate further by using LDRD or LDM, but + to keep the code simple this was not attempted in the initial + implementation. + + + * vlocks are currently only used to coordinate between CPUs which are + unable to enable their caches yet. This means that the + implementation removes many of the barriers which would be required + when executing the algorithm in cached memory. + + packing of the currently_voting array does not work with cached + memory unless all CPUs contending the lock are cache-coherent, due + to cache writebacks from one CPU clobbering values written by other + CPUs. (Though if all the CPUs are cache-coherent, you should be + probably be using proper spinlocks instead anyway). + + + * The "no votes yet" value used for the last_vote variable is 0 (not + -1 as in the pseudocode). This allows statically-allocated vlocks + to be implicitly initialised to an unlocked state simply by putting + them in .bss. + + An offset is added to each CPU's ID for the purpose of setting this + variable, so that no CPU uses the value 0 for its ID. + + +Colophon +-------- + +Originally created and documented by Dave Martin for Linaro Limited, for +use in ARM-based big.LITTLE platforms, with review and input gratefully +received from Nicolas Pitre and Achin Gupta. Thanks to Nicolas for +grabbing most of this text out of the relevant mail thread and writing +up the pseudocode. + +Copyright (C) 2012-2013 Linaro Limited +Distributed under the terms of Version 2 of the GNU General Public +License, as defined in linux/COPYING. + + +References +---------- + +[1] Lamport, L. "A New Solution of Dijkstra's Concurrent Programming + Problem", Communications of the ACM 17, 8 (August 1974), 453-455. + + http://en.wikipedia.org/wiki/Lamport%27s_bakery_algorithm + +[2] linux/arch/arm/common/vlock.S, www.kernel.org. |