[v3,00/11] Add XU support to UVC Gadget

Message

Dan Scally Jan. 30, 2023, 9:34 a.m. UTC

Hello all

This series adds support for the definition of extension units in configfs for
the UVC Gadget. The XUs are modelled as config_items within a new "extensions"
group under control, which seemed like an appropriate place to put them.

To allow the XU's to be inserted in the function graph, the bSourceID attribute
for the default output terminal is made writeable - users will need to configure
it with the bUnitID of the XU that they want to use as the OT's source. This does
mean that the XUs can _only_ be placed immediately preceding the OT, but I think
that that's fine for now.

Series level changes:

  - Added patches 5-9 which additionally add the ability to create string
  descriptors through configfs and link them to the extension units as well as
  to override the default descriptors for the IAD and VC/VS interfaces

The XUs configured through this series have been tested via uvc-gadget, uvcvideo
and uvcdynctrl.

v2 of the series here: https://lore.kernel.org/linux-usb/[e-mail]/

Thanks
Dan

Daniel Scally (11):
  usb: gadget: uvc: Make bSourceID read/write
  usb: gadget: uvc: Generalise helper functions for reuse
  usb: gadget: uvc: Allow definition of XUs in configfs
  usb: gadget: uvc: Copy XU descriptors during .bind()
  usb: gadget: configfs: Rename struct gadget_strings
  usb: gadget: configfs: Support arbitrary string descriptors
  usb: gadget: configfs: Attach arbitrary strings to cdev
  usb: gadget: uvc: Allow linking XUs to string descriptors
  usb: gadget: uvc: Pick up custom string descriptor IDs
  usb: gadget: uvc: Allow linking function to string descs
  usb: gadget: uvc: Use custom strings if available

 .../ABI/testing/configfs-usb-gadget-uvc       |  30 +-
 drivers/usb/gadget/configfs.c                 | 293 ++++++-
 drivers/usb/gadget/function/f_uvc.c           |  69 +-
 drivers/usb/gadget/function/u_uvc.h           |  15 +
 drivers/usb/gadget/function/uvc.h             |   1 +
 drivers/usb/gadget/function/uvc_configfs.c    | 771 ++++++++++++++++--
 drivers/usb/gadget/function/uvc_configfs.h    |  30 +
 include/linux/usb/composite.h                 |   1 +
 include/linux/usb/gadget.h                    |  11 +
 9 files changed, 1129 insertions(+), 92 deletions(-)