diff options
Diffstat (limited to 'Documentation/i2c')
| -rw-r--r-- | Documentation/i2c/busses/i2c-diolan-u2c | 26 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-i801 | 26 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-ismt | 36 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-parport | 2 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-parport-light | 4 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-piix4 | 12 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-sis630 | 9 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-sis96x | 2 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-taos-evm | 4 | ||||
| -rw-r--r-- | Documentation/i2c/busses/i2c-viapro | 8 | ||||
| -rw-r--r-- | Documentation/i2c/busses/scx200_acb | 2 | ||||
| -rw-r--r-- | Documentation/i2c/fault-codes | 3 | ||||
| -rw-r--r-- | Documentation/i2c/functionality | 11 | ||||
| -rw-r--r-- | Documentation/i2c/i2c-protocol | 38 | ||||
| -rw-r--r-- | Documentation/i2c/instantiating-devices | 49 | ||||
| -rw-r--r-- | Documentation/i2c/muxes/i2c-mux-gpio | 83 | ||||
| -rw-r--r-- | Documentation/i2c/smbus-protocol | 52 | ||||
| -rw-r--r-- | Documentation/i2c/ten-bit-addresses | 36 | ||||
| -rw-r--r-- | Documentation/i2c/upgrading-clients | 22 | ||||
| -rw-r--r-- | Documentation/i2c/writing-clients | 29 |
20 files changed, 363 insertions, 91 deletions
diff --git a/Documentation/i2c/busses/i2c-diolan-u2c b/Documentation/i2c/busses/i2c-diolan-u2c new file mode 100644 index 00000000000..0d6018c316c --- /dev/null +++ b/Documentation/i2c/busses/i2c-diolan-u2c @@ -0,0 +1,26 @@ +Kernel driver i2c-diolan-u2c + +Supported adapters: + * Diolan U2C-12 I2C-USB adapter + Documentation: + http://www.diolan.com/i2c/u2c12.html + +Author: Guenter Roeck <linux@roeck-us.net> + +Description +----------- + +This is the driver for the Diolan U2C-12 USB-I2C adapter. + +The Diolan U2C-12 I2C-USB Adapter provides a low cost solution to connect +a computer to I2C slave devices using a USB interface. It also supports +connectivity to SPI devices. + +This driver only supports the I2C interface of U2C-12. The driver does not use +interrupts. + + +Module parameters +----------------- + +* frequency: I2C bus frequency diff --git a/Documentation/i2c/busses/i2c-i801 b/Documentation/i2c/busses/i2c-i801 index 93fe76e5652..adf5e33e831 100644 --- a/Documentation/i2c/busses/i2c-i801 +++ b/Documentation/i2c/busses/i2c-i801 @@ -16,8 +16,17 @@ Supported adapters: * Intel EP80579 (Tolapai) * Intel 82801JI (ICH10) * Intel 5/3400 Series (PCH) - * Intel Cougar Point (PCH) + * Intel 6 Series (PCH) * Intel Patsburg (PCH) + * Intel DH89xxCC (PCH) + * Intel Panther Point (PCH) + * Intel Lynx Point (PCH) + * Intel Lynx Point-LP (PCH) + * Intel Avoton (SOC) + * Intel Wellsburg (PCH) + * Intel Coleto Creek (PCH) + * Intel Wildcat Point-LP (PCH) + * Intel BayTrail (SOC) Datasheets: Publicly available at the Intel website On Intel Patsburg and later chipsets, both the normal host SMBus controller @@ -25,7 +34,7 @@ and the additional 'Integrated Device Function' controllers are supported. Authors: Mark Studebaker <mdsxyz123@yahoo.com> - Jean Delvare <khali@linux-fr.org> + Jean Delvare <jdelvare@suse.de> Module Parameters @@ -35,9 +44,10 @@ Module Parameters Disable selected features normally supported by the device. This makes it possible to work around possible driver or hardware bugs if the feature in question doesn't work as intended for whatever reason. Bit values: - 1 disable SMBus PEC - 2 disable the block buffer - 8 disable the I2C block read functionality + 0x01 disable SMBus PEC + 0x02 disable the block buffer + 0x08 disable the I2C block read functionality + 0x10 don't use interrupts Description @@ -83,6 +93,12 @@ SMBus 2.0 Support The 82801DB (ICH4) and later chips support several SMBus 2.0 features. +Interrupt Support +----------------- + +PCI interrupt support is supported on the 82801EB (ICH5) and later chips. + + Hidden ICH SMBus ---------------- diff --git a/Documentation/i2c/busses/i2c-ismt b/Documentation/i2c/busses/i2c-ismt new file mode 100644 index 00000000000..737355822c0 --- /dev/null +++ b/Documentation/i2c/busses/i2c-ismt @@ -0,0 +1,36 @@ +Kernel driver i2c-ismt + +Supported adapters: + * Intel S12xx series SOCs + +Authors: + Bill Brown <bill.e.brown@intel.com> + + +Module Parameters +----------------- + +* bus_speed (unsigned int) +Allows changing of the bus speed. Normally, the bus speed is set by the BIOS +and never needs to be changed. However, some SMBus analyzers are too slow for +monitoring the bus during debug, thus the need for this module parameter. +Specify the bus speed in kHz. +Available bus frequency settings: + 0 no change + 80 kHz + 100 kHz + 400 kHz + 1000 kHz + + +Description +----------- + +The S12xx series of SOCs have a pair of integrated SMBus 2.0 controllers +targeted primarily at the microserver and storage markets. + +The S12xx series contain a pair of PCI functions. An output of lspci will show +something similar to the following: + + 00:13.0 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 0 + 00:13.1 System peripheral: Intel Corporation Centerton SMBus 2.0 Controller 1 diff --git a/Documentation/i2c/busses/i2c-parport b/Documentation/i2c/busses/i2c-parport index 2461c7b53b2..0e2d17b460f 100644 --- a/Documentation/i2c/busses/i2c-parport +++ b/Documentation/i2c/busses/i2c-parport @@ -1,6 +1,6 @@ Kernel driver i2c-parport -Author: Jean Delvare <khali@linux-fr.org> +Author: Jean Delvare <jdelvare@suse.de> This is a unified driver for several i2c-over-parallel-port adapters, such as the ones made by Philips, Velleman or ELV. This driver is diff --git a/Documentation/i2c/busses/i2c-parport-light b/Documentation/i2c/busses/i2c-parport-light index bdc9cbb2e0f..7071b8ba0af 100644 --- a/Documentation/i2c/busses/i2c-parport-light +++ b/Documentation/i2c/busses/i2c-parport-light @@ -1,10 +1,10 @@ Kernel driver i2c-parport-light -Author: Jean Delvare <khali@linux-fr.org> +Author: Jean Delvare <jdelvare@suse.de> This driver is a light version of i2c-parport. It doesn't depend on the parport driver, and uses direct I/O access instead. This might be -prefered on embedded systems where wasting memory for the clean but heavy +preferred on embedded systems where wasting memory for the clean but heavy parport handling is not an option. The drawback is a reduced portability and the impossibility to daisy-chain other parallel port devices. diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4 index 475bb4ae072..aa959fd2245 100644 --- a/Documentation/i2c/busses/i2c-piix4 +++ b/Documentation/i2c/busses/i2c-piix4 @@ -8,7 +8,12 @@ Supported adapters: Datasheet: Only available via NDA from ServerWorks * ATI IXP200, IXP300, IXP400, SB600, SB700 and SB800 southbridges Datasheet: Not publicly available - * AMD Hudson-2 + SB700 register reference available at: + http://support.amd.com/us/Embedded_TechDocs/43009_sb7xx_rrg_pub_1.00.pdf + * AMD SP5100 (SB700 derivative found on some server mainboards) + Datasheet: Publicly available at the AMD website + http://support.amd.com/us/Embedded_TechDocs/44413.pdf + * AMD Hudson-2, ML, CZ Datasheet: Not publicly available * Standard Microsystems (SMSC) SLC90E66 (Victory66) southbridge Datasheet: Publicly available at the SMSC website http://www.smsc.com @@ -68,6 +73,11 @@ this driver on those mainboards. The ServerWorks Southbridges, the Intel 440MX, and the Victory66 are identical to the PIIX4 in I2C/SMBus support. +The AMD SB700, SB800, SP5100 and Hudson-2 chipsets implement two +PIIX4-compatible SMBus controllers. If your BIOS initializes the +secondary controller, it will be detected by this driver as +an "Auxiliary SMBus Host Controller". + If you own Force CPCI735 motherboard or other OSB4 based systems you may need to change the SMBus Interrupt Select register so the SMBus controller uses the SMI mode. diff --git a/Documentation/i2c/busses/i2c-sis630 b/Documentation/i2c/busses/i2c-sis630 index 0b969736693..ee794363107 100644 --- a/Documentation/i2c/busses/i2c-sis630 +++ b/Documentation/i2c/busses/i2c-sis630 @@ -4,9 +4,11 @@ Supported adapters: * Silicon Integrated Systems Corp (SiS) 630 chipset (Datasheet: available at http://www.sfr-fresh.com/linux) 730 chipset + 964 chipset * Possible other SiS chipsets ? Author: Alexander Malysh <amalysh@web.de> + Amaury Decrême <amaury.decreme@gmail.com> - SiS964 support Module Parameters ----------------- @@ -18,6 +20,7 @@ Module Parameters * high_clock = [1|0] Forcibly set Host Master Clock to 56KHz (default, what your BIOS use). DANGEROUS! This should be a bit faster, but freeze some systems (i.e. my Laptop). + SIS630/730 chip only. Description @@ -36,6 +39,12 @@ or like this: 00:00.0 Host bridge: Silicon Integrated Systems [SiS] 730 Host (rev 02) 00:01.0 ISA bridge: Silicon Integrated Systems [SiS] 85C503/5513 +or like this: + +00:00.0 Host bridge: Silicon Integrated Systems [SiS] 760/M760 Host (rev 02) +00:02.0 ISA bridge: Silicon Integrated Systems [SiS] SiS964 [MuTIOL Media IO] + LPC Controller (rev 36) + in your 'lspci' output , then this driver is for your chipset. Thank You diff --git a/Documentation/i2c/busses/i2c-sis96x b/Documentation/i2c/busses/i2c-sis96x index 70e6a0cc1e1..0b979f3252a 100644 --- a/Documentation/i2c/busses/i2c-sis96x +++ b/Documentation/i2c/busses/i2c-sis96x @@ -35,7 +35,7 @@ or perhaps this... (kernel versions later than 2.4.18 may fill in the "Unknown"s) -If you cant see it please look on quirk_sis_96x_smbus +If you can't see it please look on quirk_sis_96x_smbus (drivers/pci/quirks.c) (also if southbridge detection fails) I suspect that this driver could be made to work for the following SiS diff --git a/Documentation/i2c/busses/i2c-taos-evm b/Documentation/i2c/busses/i2c-taos-evm index 9146e33be6d..60299555dcf 100644 --- a/Documentation/i2c/busses/i2c-taos-evm +++ b/Documentation/i2c/busses/i2c-taos-evm @@ -1,6 +1,6 @@ Kernel driver i2c-taos-evm -Author: Jean Delvare <khali@linux-fr.org> +Author: Jean Delvare <jdelvare@suse.de> This is a driver for the evaluation modules for TAOS I2C/SMBus chips. The modules include an SMBus master with limited capabilities, which can @@ -13,7 +13,7 @@ Currently supported devices are: * TAOS TSL2550 EVM -For addtional information on TAOS products, please see +For additional information on TAOS products, please see http://www.taosinc.com/ diff --git a/Documentation/i2c/busses/i2c-viapro b/Documentation/i2c/busses/i2c-viapro index 2e758b0e945..ab64ce21c25 100644 --- a/Documentation/i2c/busses/i2c-viapro +++ b/Documentation/i2c/busses/i2c-viapro @@ -20,12 +20,15 @@ Supported adapters: Datasheet: available on http://linux.via.com.tw * VIA Technologies, Inc. VX855/VX875 - Datasheet: Availability unknown + Datasheet: available on http://linux.via.com.tw + + * VIA Technologies, Inc. VX900 + Datasheet: available on http://linux.via.com.tw Authors: Kyösti Mälkki <kmalkki@cc.hut.fi>, Mark D. Studebaker <mdsxyz123@yahoo.com>, - Jean Delvare <khali@linux-fr.org> + Jean Delvare <jdelvare@suse.de> Module Parameters ----------------- @@ -57,6 +60,7 @@ Your lspci -n listing must show one of these : device 1106:8324 (CX700) device 1106:8353 (VX800/VX820) device 1106:8409 (VX855/VX875) + device 1106:8410 (VX900) If none of these show up, you should look in the BIOS for settings like enable ACPI / SMBus or even USB. diff --git a/Documentation/i2c/busses/scx200_acb b/Documentation/i2c/busses/scx200_acb index 7c07883d4df..ce83c871fe9 100644 --- a/Documentation/i2c/busses/scx200_acb +++ b/Documentation/i2c/busses/scx200_acb @@ -28,5 +28,5 @@ If the scx200_acb driver is built into the kernel, add the following parameter to your boot command line: scx200_acb.base=0x810,0x820 If the scx200_acb driver is built as a module, add the following line to -the file /etc/modprobe.conf instead: +a configuration file in /etc/modprobe.d/ instead: options scx200_acb base=0x810,0x820 diff --git a/Documentation/i2c/fault-codes b/Documentation/i2c/fault-codes index 045765c0b9b..47c25abb7d5 100644 --- a/Documentation/i2c/fault-codes +++ b/Documentation/i2c/fault-codes @@ -64,9 +64,6 @@ EINVAL detected before any I/O operation was started. Use a more specific fault code when you can. - One example would be a driver trying an SMBus Block Write - with block size outside the range of 1-32 bytes. - EIO This rather vague error means something went wrong when performing an I/O operation. Use a more specific fault diff --git a/Documentation/i2c/functionality b/Documentation/i2c/functionality index 42c17c1fb3c..4556a3eb87c 100644 --- a/Documentation/i2c/functionality +++ b/Documentation/i2c/functionality @@ -18,9 +18,9 @@ For the most up-to-date list of functionality constants, please check adapters typically can not do these) I2C_FUNC_10BIT_ADDR Handles the 10-bit address extensions I2C_FUNC_PROTOCOL_MANGLING Knows about the I2C_M_IGNORE_NAK, - I2C_M_REV_DIR_ADDR, I2C_M_NOSTART and - I2C_M_NO_RD_ACK flags (which modify the - I2C protocol!) + I2C_M_REV_DIR_ADDR and I2C_M_NO_RD_ACK + flags (which modify the I2C protocol!) + I2C_FUNC_NOSTART Can skip repeated start sequence I2C_FUNC_SMBUS_QUICK Handles the SMBus write_quick command I2C_FUNC_SMBUS_READ_BYTE Handles the SMBus read_byte command I2C_FUNC_SMBUS_WRITE_BYTE Handles the SMBus write_byte command @@ -46,10 +46,13 @@ A few combinations of the above flags are also defined for your convenience: and write_block_data commands I2C_FUNC_SMBUS_I2C_BLOCK Handles the SMBus read_i2c_block_data and write_i2c_block_data commands - I2C_FUNC_SMBUS_EMUL Handles all SMBus commands than can be + I2C_FUNC_SMBUS_EMUL Handles all SMBus commands that can be emulated by a real I2C adapter (using the transparent emulation layer) +In kernel versions prior to 3.5 I2C_FUNC_NOSTART was implemented as +part of I2C_FUNC_PROTOCOL_MANGLING. + ADAPTER IMPLEMENTATION ---------------------- diff --git a/Documentation/i2c/i2c-protocol b/Documentation/i2c/i2c-protocol index 10518dd5881..ff6d6cee6c7 100644 --- a/Documentation/i2c/i2c-protocol +++ b/Documentation/i2c/i2c-protocol @@ -6,8 +6,8 @@ Key to symbols S (1 bit) : Start bit P (1 bit) : Stop bit Rd/Wr (1 bit) : Read/Write bit. Rd equals 1, Wr equals 0. -A, NA (1 bit) : Accept and reverse accept bit. -Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to +A, NA (1 bit) : Accept and reverse accept bit. +Addr (7 bits): I2C 7 bit address. Note that this can be expanded as usual to get a 10 bit I2C address. Comm (8 bits): Command byte, a data byte which often selects a register on the device. @@ -49,9 +49,20 @@ a byte read, followed by a byte write: Modified transactions ===================== -We have found some I2C devices that needs the following modifications: +The following modifications to the I2C protocol can also be generated by +setting these flags for i2c messages. With the exception of I2C_M_NOSTART, they +are usually only needed to work around device issues: - Flag I2C_M_NOSTART: +I2C_M_IGNORE_NAK: + Normally message is interrupted immediately if there is [NA] from the + client. Setting this flag treats any [NA] as [A], and all of + message is sent. + These messages may still fail to SCL lo->hi timeout. + +I2C_M_NO_RD_ACK: + In a read message, master A/NA bit is skipped. + +I2C_M_NOSTART: In a combined transaction, no 'S Addr Wr/Rd [A]' is generated at some point. For example, setting I2C_M_NOSTART on the second partial message generates something like: @@ -60,17 +71,18 @@ We have found some I2C devices that needs the following modifications: we do not generate Addr, but we do generate the startbit S. This will probably confuse all other clients on your bus, so don't try this. - Flags I2C_M_REV_DIR_ADDR + This is often used to gather transmits from multiple data buffers in + system memory into something that appears as a single transfer to the + I2C device but may also be used between direction changes by some + rare devices. + +I2C_M_REV_DIR_ADDR: This toggles the Rd/Wr flag. That is, if you want to do a write, but need to emit an Rd instead of a Wr, or vice versa, you set this flag. For example: S Addr Rd [A] Data [A] Data [A] ... [A] Data [A] P - Flags I2C_M_IGNORE_NAK - Normally message is interrupted immediately if there is [NA] from the - client. Setting this flag treats any [NA] as [A], and all of - message is sent. - These messages may still fail to SCL lo->hi timeout. - - Flags I2C_M_NO_RD_ACK - In a read message, master A/NA bit is skipped. +I2C_M_STOP: + Force a stop condition (P) after the message. Some I2C related protocols + like SCCB require that. Normally, you really don't want to get interrupted + between the messages of one transfer. diff --git a/Documentation/i2c/instantiating-devices b/Documentation/i2c/instantiating-devices index 87da405a859..0d85ac1935b 100644 --- a/Documentation/i2c/instantiating-devices +++ b/Documentation/i2c/instantiating-devices @@ -8,8 +8,8 @@ reason, the kernel code must instantiate I2C devices explicitly. There are several ways to achieve this, depending on the context and requirements. -Method 1: Declare the I2C devices by bus number ------------------------------------------------ +Method 1a: Declare the I2C devices by bus number +------------------------------------------------ This method is appropriate when the I2C bus is a system bus as is the case for many embedded systems. On such systems, each I2C bus has a number @@ -19,7 +19,7 @@ i2c_board_info which is registered by calling i2c_register_board_info(). Example (from omap2 h4): -static struct i2c_board_info __initdata h4_i2c_board_info[] = { +static struct i2c_board_info h4_i2c_board_info[] __initdata = { { I2C_BOARD_INFO("isp1301_omap", 0x2d), .irq = OMAP_GPIO_IRQ(125), @@ -51,6 +51,43 @@ The devices will be automatically unbound and destroyed when the I2C bus they sit on goes away (if ever.) +Method 1b: Declare the I2C devices via devicetree +------------------------------------------------- + +This method has the same implications as method 1a. The declaration of I2C +devices is here done via devicetree as subnodes of the master controller. + +Example: + + i2c1: i2c@400a0000 { + /* ... master properties skipped ... */ + clock-frequency = <100000>; + + flash@50 { + compatible = "atmel,24c256"; + reg = <0x50>; + }; + + pca9532: gpio@60 { + compatible = "nxp,pca9532"; + gpio-controller; + #gpio-cells = <2>; + reg = <0x60>; + }; + }; + +Here, two devices are attached to the bus using a speed of 100kHz. For +additional properties which might be needed to set up the device, please refer +to its devicetree documentation in Documentation/devicetree/bindings/. + + +Method 1c: Declare the I2C devices via ACPI +------------------------------------------- + +ACPI can also describe I2C devices. There is special documentation for this +which is currently located at Documentation/acpi/enumeration.txt. + + Method 2: Instantiate the devices explicitly -------------------------------------------- @@ -87,11 +124,11 @@ it may have different addresses from one board to the next (manufacturer changing its design without notice). In this case, you can call i2c_new_probed_device() instead of i2c_new_device(). -Example (from the pnx4008 OHCI driver): +Example (from the nxp OHCI driver): static const unsigned short normal_i2c[] = { 0x2c, 0x2d, I2C_CLIENT_END }; -static int __devinit usb_hcd_pnx4008_probe(struct platform_device *pdev) +static int usb_hcd_nxp_probe(struct platform_device *pdev) { (...) struct i2c_adapter *i2c_adap; @@ -100,7 +137,7 @@ static int __devinit usb_hcd_pnx4008_probe(struct platform_device *pdev) (...) i2c_adap = i2c_get_adapter(2); memset(&i2c_info, 0, sizeof(struct i2c_board_info)); - strlcpy(i2c_info.name, "isp1301_pnx", I2C_NAME_SIZE); + strlcpy(i2c_info.type, "isp1301_nxp", I2C_NAME_SIZE); isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info, normal_i2c, NULL); i2c_put_adapter(i2c_adap); diff --git a/Documentation/i2c/muxes/i2c-mux-gpio b/Documentation/i2c/muxes/i2c-mux-gpio new file mode 100644 index 00000000000..d4d91a53fc3 --- /dev/null +++ b/Documentation/i2c/muxes/i2c-mux-gpio @@ -0,0 +1,83 @@ +Kernel driver i2c-gpio-mux + +Author: Peter Korsgaard <peter.korsgaard@barco.com> + +Description +----------- + +i2c-gpio-mux is an i2c mux driver providing access to I2C bus segments +from a master I2C bus and a hardware MUX controlled through GPIO pins. + +E.G.: + + ---------- ---------- Bus segment 1 - - - - - + | | SCL/SDA | |-------------- | | + | |------------| | + | | | | Bus segment 2 | | + | Linux | GPIO 1..N | MUX |--------------- Devices + | |------------| | | | + | | | | Bus segment M + | | | |---------------| | + ---------- ---------- - - - - - + +SCL/SDA of the master I2C bus is multiplexed to bus segment 1..M +according to the settings of the GPIO pins 1..N. + +Usage +----- + +i2c-gpio-mux uses the platform bus, so you need to provide a struct +platform_device with the platform_data pointing to a struct +gpio_i2cmux_platform_data with the I2C adapter number of the master +bus, the number of bus segments to create and the GPIO pins used +to control it. See include/linux/i2c-gpio-mux.h for details. + +E.G. something like this for a MUX providing 4 bus segments +controlled through 3 GPIO pins: + +#include <linux/i2c-gpio-mux.h> +#include <linux/platform_device.h> + +static const unsigned myboard_gpiomux_gpios[] = { + AT91_PIN_PC26, AT91_PIN_PC25, AT91_PIN_PC24 +}; + +static const unsigned myboard_gpiomux_values[] = { + 0, 1, 2, 3 +}; + +static struct gpio_i2cmux_platform_data myboard_i2cmux_data = { + .parent = 1, + .base_nr = 2, /* optional */ + .values = myboard_gpiomux_values, + .n_values = ARRAY_SIZE(myboard_gpiomux_values), + .gpios = myboard_gpiomux_gpios, + .n_gpios = ARRAY_SIZE(myboard_gpiomux_gpios), + .idle = 4, /* optional */ +}; + +static struct platform_device myboard_i2cmux = { + .name = "i2c-gpio-mux", + .id = 0, + .dev = { + .platform_data = &myboard_i2cmux_data, + }, +}; + +If you don't know the absolute GPIO pin numbers at registration time, +you can instead provide a chip name (.chip_name) and relative GPIO pin +numbers, and the i2c-gpio-mux driver will do the work for you, +including deferred probing if the GPIO chip isn't immediately +available. + +Device Registration +------------------- + +When registering your i2c-gpio-mux device, you should pass the number +of any GPIO pin it uses as the device ID. This guarantees that every +instance has a different ID. + +Alternatively, if you don't need a stable device name, you can simply +pass PLATFORM_DEVID_AUTO as the device ID, and the platform core will +assign a dynamic ID to your device. If you do not know the absolute +GPIO pin numbers at registration time, this is even the only option. diff --git a/Documentation/i2c/smbus-protocol b/Documentation/i2c/smbus-protocol index 7c19d1a2bea..6012b12b351 100644 --- a/Documentation/i2c/smbus-protocol +++ b/Documentation/i2c/smbus-protocol @@ -23,6 +23,12 @@ don't match these function names. For some of the operations which pass a single data byte, the functions using SMBus protocol operation names execute a different protocol operation entirely. +Each transaction type corresponds to a functionality flag. Before calling a +transaction function, a device driver should always check (just once) for +the corresponding functionality flag to ensure that the underlying I2C +adapter supports the transaction in question. See +<file:Documentation/i2c/functionality> for the details. + Key to symbols ============== @@ -49,6 +55,8 @@ This sends a single bit to the device, at the place of the Rd/Wr bit. A Addr Rd/Wr [A] P +Functionality flag: I2C_FUNC_SMBUS_QUICK + SMBus Receive Byte: i2c_smbus_read_byte() ========================================== @@ -60,6 +68,8 @@ the previous SMBus command. S Addr Rd [A] [Data] NA P +Functionality flag: I2C_FUNC_SMBUS_READ_BYTE + SMBus Send Byte: i2c_smbus_write_byte() ======================================== @@ -69,6 +79,8 @@ to a device. See Receive Byte for more information. S Addr Wr [A] Data [A] P +Functionality flag: I2C_FUNC_SMBUS_WRITE_BYTE + SMBus Read Byte: i2c_smbus_read_byte_data() ============================================ @@ -78,6 +90,8 @@ The register is specified through the Comm byte. S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] NA P +Functionality flag: I2C_FUNC_SMBUS_READ_BYTE_DATA + SMBus Read Word: i2c_smbus_read_word_data() ============================================ @@ -88,6 +102,12 @@ byte. But this time, the data is a complete word (16 bits). S Addr Wr [A] Comm [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P +Functionality flag: I2C_FUNC_SMBUS_READ_WORD_DATA + +Note the convenience function i2c_smbus_read_word_swapped is +available for reads where the two data bytes are the other way +around (not SMBus compliant, but very popular.) + SMBus Write Byte: i2c_smbus_write_byte_data() ============================================== @@ -98,6 +118,8 @@ the Read Byte operation. S Addr Wr [A] Comm [A] Data [A] P +Functionality flag: I2C_FUNC_SMBUS_WRITE_BYTE_DATA + SMBus Write Word: i2c_smbus_write_word_data() ============================================== @@ -108,9 +130,15 @@ specified through the Comm byte. S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] P +Functionality flag: I2C_FUNC_SMBUS_WRITE_WORD_DATA + +Note the convenience function i2c_smbus_write_word_swapped is +available for writes where the two data bytes are the other way +around (not SMBus compliant, but very popular.) -SMBus Process Call: i2c_smbus_process_call() -============================================= + +SMBus Process Call: +=================== This command selects a device register (through the Comm byte), sends 16 bits of data to it, and reads 16 bits of data in return. @@ -118,6 +146,8 @@ This command selects a device register (through the Comm byte), sends S Addr Wr [A] Comm [A] DataLow [A] DataHigh [A] S Addr Rd [A] [DataLow] A [DataHigh] NA P +Functionality flag: I2C_FUNC_SMBUS_PROC_CALL + SMBus Block Read: i2c_smbus_read_block_data() ============================================== @@ -129,6 +159,8 @@ of data is specified by the device in the Count byte. S Addr Wr [A] Comm [A] S Addr Rd [A] [Count] A [Data] A [Data] A ... A [Data] NA P +Functionality flag: I2C_FUNC_SMBUS_READ_BLOCK_DATA + SMBus Block Write: i2c_smbus_write_block_data() ================================================ @@ -139,6 +171,8 @@ Comm byte. The amount of data is specified in the Count byte. S Addr Wr [A] Comm [A] Count [A] Data [A] Data [A] ... [A] Data [A] P +Functionality flag: I2C_FUNC_SMBUS_WRITE_BLOCK_DATA + SMBus Block Write - Block Read Process Call =========================================== @@ -152,6 +186,8 @@ This command selects a device register (through the Comm byte), sends S Addr Wr [A] Comm [A] Count [A] Data [A] ... S Addr Rd [A] [Count] A [Data] ... A P +Functionality flag: I2C_FUNC_SMBUS_BLOCK_PROC_CALL + SMBus Host Notify ================= @@ -221,15 +257,7 @@ designated register that is specified through the Comm byte. S Addr Wr [A] Comm [A] S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P - -I2C Block Read (2 Comm bytes) -============================= - -This command reads a block of bytes from a device, from a -designated register that is specified through the two Comm bytes. - -S Addr Wr [A] Comm1 [A] Comm2 [A] - S Addr Rd [A] [Data] A [Data] A ... A [Data] NA P +Functionality flag: I2C_FUNC_SMBUS_READ_I2C_BLOCK I2C Block Write: i2c_smbus_write_i2c_block_data() @@ -241,3 +269,5 @@ Comm byte. Note that command lengths of 0, 2, or more bytes are supported as they are indistinguishable from data. S Addr Wr [A] Comm [A] Data [A] Data [A] ... [A] Data [A] P + +Functionality flag: I2C_FUNC_SMBUS_WRITE_I2C_BLOCK diff --git a/Documentation/i2c/ten-bit-addresses b/Documentation/i2c/ten-bit-addresses index e9890709c50..cdfe13901b9 100644 --- a/Documentation/i2c/ten-bit-addresses +++ b/Documentation/i2c/ten-bit-addresses @@ -1,22 +1,24 @@ The I2C protocol knows about two kinds of device addresses: normal 7 bit addresses, and an extended set of 10 bit addresses. The sets of addresses do not intersect: the 7 bit address 0x10 is not the same as the 10 bit -address 0x10 (though a single device could respond to both of them). You -select a 10 bit address by adding an extra byte after the address -byte: - S Addr7 Rd/Wr .... -becomes - S 11110 Addr10 Rd/Wr -S is the start bit, Rd/Wr the read/write bit, and if you count the number -of bits, you will see the there are 8 after the S bit for 7 bit addresses, -and 16 after the S bit for 10 bit addresses. +address 0x10 (though a single device could respond to both of them). -WARNING! The current 10 bit address support is EXPERIMENTAL. There are -several places in the code that will cause SEVERE PROBLEMS with 10 bit -addresses, even though there is some basic handling and hooks. Also, -almost no supported adapter handles the 10 bit addresses correctly. +I2C messages to and from 10-bit address devices have a different format. +See the I2C specification for the details. -As soon as a real 10 bit address device is spotted 'in the wild', we -can and will add proper support. Right now, 10 bit address devices -are defined by the I2C protocol, but we have never seen a single device -which supports them. +The current 10 bit address support is minimal. It should work, however +you can expect some problems along the way: +* Not all bus drivers support 10-bit addresses. Some don't because the + hardware doesn't support them (SMBus doesn't require 10-bit address + support for example), some don't because nobody bothered adding the + code (or it's there but not working properly.) Software implementation + (i2c-algo-bit) is known to work. +* Some optional features do not support 10-bit addresses. This is the + case of automatic detection and instantiation of devices by their, + drivers, for example. +* Many user-space packages (for example i2c-tools) lack support for + 10-bit addresses. + +Note that 10-bit address devices are still pretty rare, so the limitations +listed above could stay for a long time, maybe even forever if nobody +needs them to be fixed. diff --git a/Documentation/i2c/upgrading-clients b/Documentation/i2c/upgrading-clients index 9a45f9bb6a2..8e5fbd88c7d 100644 --- a/Documentation/i2c/upgrading-clients +++ b/Documentation/i2c/upgrading-clients @@ -61,7 +61,7 @@ static int example_attach(struct i2c_adapter *adap, int addr, int kind) return 0; } -static int __devexit example_detach(struct i2c_client *client) +static int example_detach(struct i2c_client *client) { struct example_state *state = i2c_get_clientdata(client); @@ -81,7 +81,7 @@ static struct i2c_driver example_driver = { .name = "example", }, .attach_adapter = example_attach_adapter, - .detach_client = __devexit_p(example_detach), + .detach_client = example_detach, .suspend = example_suspend, .resume = example_resume, }; @@ -93,7 +93,7 @@ Updating the client The new style binding model will check against a list of supported devices and their associated address supplied by the code registering the busses. This means that the driver .attach_adapter and -.detach_adapter methods can be removed, along with the addr_data, +.detach_client methods can be removed, along with the addr_data, as follows: - static struct i2c_driver example_driver; @@ -110,14 +110,14 @@ as follows: static struct i2c_driver example_driver = { - .attach_adapter = example_attach_adapter, -- .detach_client = __devexit_p(example_detach), +- .detach_client = example_detach, } Add the probe and remove methods to the i2c_driver, as so: static struct i2c_driver example_driver = { + .probe = example_probe, -+ .remove = __devexit_p(example_remove), ++ .remove = example_remove, } Change the example_attach method to accept the new parameters @@ -196,11 +196,11 @@ static int example_probe(struct i2c_client *i2c_client, Update the detach method, by changing the name to _remove and to delete the i2c_detach_client call. It is possible that you -can also remove the ret variable as it is not not needed for -any of the core functions. +can also remove the ret variable as it is not needed for any +of the core functions. -- static int __devexit example_detach(struct i2c_client *client) -+ static int __devexit example_remove(struct i2c_client *client) +- static int example_detach(struct i2c_client *client) ++ static int example_remove(struct i2c_client *client) { struct example_state *state = i2c_get_clientdata(client); @@ -253,7 +253,7 @@ static int example_probe(struct i2c_client *client, return 0; } -static int __devexit example_remove(struct i2c_client *client) +static int example_remove(struct i2c_client *client) { struct example_state *state = i2c_get_clientdata(client); @@ -275,7 +275,7 @@ static struct i2c_driver example_driver = { }, .id_table = example_idtable, .probe = example_probe, - .remove = __devexit_p(example_remove), + .remove = example_remove, .suspend = example_suspend, .resume = example_resume, }; diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 5ebf5af1d71..6b344b516bf 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -38,7 +38,7 @@ static struct i2c_driver foo_driver = { .name = "foo", }, - .id_table = foo_ids, + .id_table = foo_idtable, .probe = foo_probe, .remove = foo_remove, /* if device autodetection is needed: */ @@ -245,21 +245,17 @@ static int __init foo_init(void) { return i2c_add_driver(&foo_driver); } +module_init(foo_init); static void __exit foo_cleanup(void) { i2c_del_driver(&foo_driver); } +module_exit(foo_cleanup); -/* Substitute your own name and email address */ -MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>" -MODULE_DESCRIPTION("Driver for Barf Inc. Foo I2C devices"); - -/* a few non-GPL license types are also allowed */ -MODULE_LICENSE("GPL"); +The module_i2c_driver() macro can be used to reduce above code. -module_init(foo_init); -module_exit(foo_cleanup); +module_i2c_driver(foo_driver); Note that some functions are marked by `__init'. These functions can be removed after kernel booting (or module loading) is completed. @@ -267,6 +263,17 @@ Likewise, functions marked by `__exit' are dropped by the compiler when the code is built into the kernel, as they would never be called. +Driver Information +================== + +/* Substitute your own name and email address */ +MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>" +MODULE_DESCRIPTION("Driver for Barf Inc. Foo I2C devices"); + +/* a few non-GPL license types are also allowed */ +MODULE_LICENSE("GPL"); + + Power Management ================ @@ -358,8 +365,6 @@ in terms of it. Never use this function directly! s32 i2c_smbus_read_word_data(struct i2c_client *client, u8 command); s32 i2c_smbus_write_word_data(struct i2c_client *client, u8 command, u16 value); - s32 i2c_smbus_process_call(struct i2c_client *client, - u8 command, u16 value); s32 i2c_smbus_read_block_data(struct i2c_client *client, u8 command, u8 *values); s32 i2c_smbus_write_block_data(struct i2c_client *client, @@ -374,6 +379,8 @@ These ones were removed from i2c-core because they had no users, but could be added back later if needed: s32 i2c_smbus_write_quick(struct i2c_client *client, u8 value); + s32 i2c_smbus_process_call(struct i2c_client *client, + u8 command, u16 value); s32 i2c_smbus_block_process_call(struct i2c_client *client, u8 command, u8 length, u8 *values); |