diff options
Diffstat (limited to 'Documentation/usb')
| -rw-r--r-- | Documentation/usb/URB.txt | 21 | ||||
| -rw-r--r-- | Documentation/usb/WUSB-Design-overview.txt | 2 | ||||
| -rw-r--r-- | Documentation/usb/chipidea.txt | 71 | ||||
| -rw-r--r-- | Documentation/usb/gadget_configfs.txt | 6 | ||||
| -rw-r--r-- | Documentation/usb/gadget_multi.txt | 2 | ||||
| -rw-r--r-- | Documentation/usb/mass-storage.txt | 2 | ||||
| -rw-r--r-- | Documentation/usb/proc_usb_info.txt | 9 |
7 files changed, 93 insertions, 20 deletions
diff --git a/Documentation/usb/URB.txt b/Documentation/usb/URB.txt index 00d2c644068..50da0d45544 100644 --- a/Documentation/usb/URB.txt +++ b/Documentation/usb/URB.txt @@ -195,13 +195,12 @@ by the completion handler. The handler is of the following type: - typedef void (*usb_complete_t)(struct urb *, struct pt_regs *) + typedef void (*usb_complete_t)(struct urb *) -I.e., it gets the URB that caused the completion call, plus the -register values at the time of the corresponding interrupt (if any). -In the completion handler, you should have a look at urb->status to -detect any USB errors. Since the context parameter is included in the URB, -you can pass information to the completion handler. +I.e., it gets the URB that caused the completion call. In the completion +handler, you should have a look at urb->status to detect any USB errors. +Since the context parameter is included in the URB, you can pass +information to the completion handler. Note that even when an error (or unlink) is reported, data may have been transferred. That's because USB transfers are packetized; it might take @@ -210,12 +209,12 @@ have transferred successfully before the completion was called. NOTE: ***** WARNING ***** -NEVER SLEEP IN A COMPLETION HANDLER. These are normally called -during hardware interrupt processing. If you can, defer substantial -work to a tasklet (bottom half) to keep system latencies low. You'll -probably need to use spinlocks to protect data structures you manipulate -in completion handlers. +NEVER SLEEP IN A COMPLETION HANDLER. These are often called in atomic +context. +In the current kernel, completion handlers run with local interrupts +disabled, but in the future this will be changed, so don't assume that +local IRQs are always disabled inside completion handlers. 1.8. How to do isochronous (ISO) transfers? diff --git a/Documentation/usb/WUSB-Design-overview.txt b/Documentation/usb/WUSB-Design-overview.txt index 4c5e3793934..1cd07c017cf 100644 --- a/Documentation/usb/WUSB-Design-overview.txt +++ b/Documentation/usb/WUSB-Design-overview.txt @@ -25,7 +25,7 @@ updated content. * Design-overview.txt-1.8 This code implements a Ultra Wide Band stack for Linux, as well as -drivers for the the USB based UWB radio controllers defined in the +drivers for the USB based UWB radio controllers defined in the Wireless USB 1.0 specification (including Wireless USB host controller and an Intel WiNET controller). diff --git a/Documentation/usb/chipidea.txt b/Documentation/usb/chipidea.txt new file mode 100644 index 00000000000..995c8bca40e --- /dev/null +++ b/Documentation/usb/chipidea.txt @@ -0,0 +1,71 @@ +1. How to test OTG FSM(HNP and SRP) +----------------------------------- +To show how to demo OTG HNP and SRP functions via sys input files +with 2 Freescale i.MX6Q sabre SD boards. + +1.1 How to enable OTG FSM in menuconfig +--------------------------------------- +Select CONFIG_USB_OTG_FSM, rebuild kernel Image and modules. +If you want to check some internal variables for otg fsm, +select CONFIG_USB_CHIPIDEA_DEBUG, there are 2 files which +can show otg fsm variables and some controller registers value: +cat /sys/kernel/debug/ci_hdrc.0/otg +cat /sys/kernel/debug/ci_hdrc.0/registers + +1.2 Test operations +------------------- +1) Power up 2 Freescale i.MX6Q sabre SD boards with gadget class driver loaded + (e.g. g_mass_storage). + +2) Connect 2 boards with usb cable with one end is micro A plug, the other end + is micro B plug. + + The A-device(with micro A plug inserted) should enumrate B-device. + +3) Role switch + On B-device: + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + + if HNP polling is not supported, also need: + On A-device: + echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req + + B-device should take host role and enumrate A-device. + +4) A-device switch back to host. + On B-device: + echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + + A-device should switch back to host and enumrate B-device. + +5) Remove B-device(unplug micro B plug) and insert again in 10 seconds, + A-device should enumrate B-device again. + +6) Remove B-device(unplug micro B plug) and insert again after 10 seconds, + A-device should NOT enumrate B-device. + + if A-device wants to use bus: + On A-device: + echo 0 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_req + + if B-device wants to use bus: + On B-device: + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + +7) A-device power down the bus. + On A-device: + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/a_bus_drop + + A-device should disconnect with B-device and power down the bus. + +8) B-device does data pulse for SRP. + On B-device: + echo 1 > /sys/bus/platform/devices/ci_hdrc.0/inputs/b_bus_req + + A-device should resume usb bus and enumrate B-device. + +1.3 Reference document +---------------------- +"On-The-Go and Embedded Host Supplement to the USB Revision 2.0 Specification +July 27, 2012 Revision 2.0 version 1.1a" diff --git a/Documentation/usb/gadget_configfs.txt b/Documentation/usb/gadget_configfs.txt index 8ec2a67c39b..4cf53e40661 100644 --- a/Documentation/usb/gadget_configfs.txt +++ b/Documentation/usb/gadget_configfs.txt @@ -26,7 +26,7 @@ Linux provides a number of functions for gadgets to use. Creating a gadget means deciding what configurations there will be and which functions each configuration will provide. -Configfs (please see Documentation/filesystems/configfs/*) lends itslef nicely +Configfs (please see Documentation/filesystems/configfs/*) lends itself nicely for the purpose of telling the kernel about the above mentioned decision. This document is about how to do it. @@ -99,7 +99,7 @@ directories must be created: $ mkdir configs/<name>.<number> where <name> can be any string which is legal in a filesystem and the -<numebr> is the configuration's number, e.g.: +<number> is the configuration's number, e.g.: $ mkdir configs/c.1 @@ -327,7 +327,7 @@ from the buffer to the cs), but it is up to the implementer of the two functions to decide what they actually do. typedef struct configured_structure cs; -typedef struc specific_attribute sa; +typedef struct specific_attribute sa; sa +----------------------------------+ diff --git a/Documentation/usb/gadget_multi.txt b/Documentation/usb/gadget_multi.txt index 80f4ef0eb75..7d66a8636cb 100644 --- a/Documentation/usb/gadget_multi.txt +++ b/Documentation/usb/gadget_multi.txt @@ -14,7 +14,7 @@ A CDC ECM (Ethernet) function may be turned on via a Kconfig option and RNDIS can be turned off. If they are both enabled the gadget will have two configurations -- one with RNDIS and another with CDC ECM[3]. -Please not that if you use non-standard configuration (that is enable +Please note that if you use non-standard configuration (that is enable CDC ECM) you may need to change vendor and/or product ID. * Host drivers diff --git a/Documentation/usb/mass-storage.txt b/Documentation/usb/mass-storage.txt index 59063ad7a60..e89803a5a96 100644 --- a/Documentation/usb/mass-storage.txt +++ b/Documentation/usb/mass-storage.txt @@ -13,7 +13,7 @@ operation. Note that the driver is slightly non-portable in that it assumes - a single memory/DMA buffer will be useable for bulk-in and bulk-out + a single memory/DMA buffer will be usable for bulk-in and bulk-out endpoints. With most device controllers this is not an issue, but there may be some with hardware restrictions that prevent a buffer from being used by more than one endpoint. diff --git a/Documentation/usb/proc_usb_info.txt b/Documentation/usb/proc_usb_info.txt index c9c3f0f5ad7..98be9198267 100644 --- a/Documentation/usb/proc_usb_info.txt +++ b/Documentation/usb/proc_usb_info.txt @@ -54,9 +54,12 @@ it and 002/048 sometime later. These files can be read as binary data. The binary data consists of first the device descriptor, then the descriptors for each -configuration of the device. Multi-byte fields in the device and -configuration descriptors, but not other descriptors, are converted -to host endianness by the kernel. This information is also shown +configuration of the device. Multi-byte fields in the device descriptor +are converted to host endianness by the kernel. The configuration +descriptors are in bus endian format! The configuration descriptor +are wTotalLength bytes apart. If a device returns less configuration +descriptor data than indicated by wTotalLength there will be a hole in +the file for the missing bytes. This information is also shown in text form by the /proc/bus/usb/devices file, described later. These files may also be used to write user-level drivers for the USB |