linux/Documentation/ABI/testing/configfs-usb-gadget
Andrzej Pietrasiewicz da4243145f usb: gadget: configfs: OS Extended Compatibility descriptors support
Add handling of OS Extended Compatibility descriptors from configfs interface.
Hosts which expect the "OS Descriptors" ask only for configurations @ index 0,
but linux-based USB devices can provide more than one configuration.
This patch adds marking one of gadget's configurations the configuration
to be reported at index 0, regardless of the actual sequence of usb_add_config
invocations used for adding the configurations. The configuration is selected
by creating a symbolic link pointing to it from the "os_desc" directory
located at the top of a gadget's directory hierarchy.

One kind of "OS Descriptors" are "Extended Compatibility Descriptors",
which need to be specified per interface. This patch adds interface.<n>
directory in function's configfs directory to represent each interface
defined by the function. Each interface's directory contains two attributes:
"compatible_id" and "sub_compatible_id", which represent 8-byte
strings to be reported to the host as the "Compatible ID" and "Sub Compatible
ID".

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
2014-05-14 09:39:25 -05:00

106 lines
2.8 KiB
Plaintext

What: /config/usb-gadget
Date: Jun 2013
KernelVersion: 3.11
Description:
This group contains sub-groups corresponding to created
USB gadgets.
What: /config/usb-gadget/gadget
Date: Jun 2013
KernelVersion: 3.11
Description:
The attributes of a gadget:
UDC - bind a gadget to UDC/unbind a gadget;
write UDC's name found in /sys/class/udc/*
to bind a gadget, empty string "" to unbind.
bDeviceClass - USB device class code
bDeviceSubClass - USB device subclass code
bDeviceProtocol - USB device protocol code
bMaxPacketSize0 - maximum endpoint 0 packet size
bcdDevice - bcd device release number
bcdUSB - bcd USB specification version number
idProduct - product ID
idVendor - vendor ID
What: /config/usb-gadget/gadget/configs
Date: Jun 2013
KernelVersion: 3.11
Description:
This group contains a USB gadget's configurations
What: /config/usb-gadget/gadget/configs/config
Date: Jun 2013
KernelVersion: 3.11
Description:
The attributes of a configuration:
bmAttributes - configuration characteristics
MaxPower - maximum power consumption from the bus
What: /config/usb-gadget/gadget/configs/config/strings
Date: Jun 2013
KernelVersion: 3.11
Description:
This group contains subdirectories for language-specific
strings for this configuration.
What: /config/usb-gadget/gadget/configs/config/strings/language
Date: Jun 2013
KernelVersion: 3.11
Description:
The attributes:
configuration - configuration description
What: /config/usb-gadget/gadget/functions
Date: Jun 2013
KernelVersion: 3.11
Description:
This group contains functions available to this USB gadget.
What: /config/usb-gadget/gadget/functions/<func>.<inst>/interface.<n>
Date: May 2014
KernelVersion: 3.16
Description:
This group contains "Feature Descriptors" specific for one
gadget's USB interface or one interface group described
by an IAD.
The attributes:
compatible_id - 8-byte string for "Compatible ID"
sub_compatible_id - 8-byte string for "Sub Compatible ID"
What: /config/usb-gadget/gadget/strings
Date: Jun 2013
KernelVersion: 3.11
Description:
This group contains subdirectories for language-specific
strings for this gadget.
What: /config/usb-gadget/gadget/strings/language
Date: Jun 2013
KernelVersion: 3.11
Description:
The attributes:
serialnumber - gadget's serial number (string)
product - gadget's product description
manufacturer - gadget's manufacturer description
What: /config/usb-gadget/gadget/os_desc
Date: May 2014
KernelVersion: 3.16
Description:
This group contains "OS String" extension handling attributes.
use - flag turning "OS Desctiptors" support on/off
b_vendor_code - one-byte value used for custom per-device and
per-interface requests
qw_sign - an identifier to be reported as "OS String"
proper