If the user has defined a custom string descriptor for the IAD or the
VideoStreaming interfaces then set their index field to point to the
custom descriptor instead of the hardcoded defaults. If no custom
descriptors have been linked to, then use the default ones.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-12-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

If any custom string descriptors have been linked to from the
extension unit, pick up the string ID that was returned when
the strings were attached to the composite dev and use it to
set the iExtension field of the Extension Unit Descriptor.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-10-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that extension unit support is available through configfs we need
to copy the descriptors for the XUs during uvc_function_bind() so that
they're exposed to the usb subsystem.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-5-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The UVC gadget at present has no support for extension units. Add the
infrastructure to uvc_configfs.c that allows users to create XUs via
configfs. These will be stored in a new child of uvcg_control_grp_type
with the name "extensions".

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-4-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

A hardcoded default color matching descriptor is embedded in struct
f_uvc_opts but no longer has any use - remove it.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230202114142.300858-5-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The f_uvc code includes an interrupt endpoint against the VideoControl
interface. According to section 2.4.2 of the UVC specification however
this endpoint is optional in at least some cases:

"This endpoint is optional, but may be mandatory under certain
conditions"

The conditions enumerated are whether...

1. The device supports hardware triggers
2. The device implements any AutoUpdate controls
3. The device implements any Asynchronous controls

As all of those things are implementation dependent, this endpoint
might be unnecessary for some users. Further to that it is unusable
in the current implementation as there is no mechanism within the
UVC gadget driver that allows data to be sent over that endpoint.
Disable the interrupt endpoint by default, but check whether the
user has asked for it to be enabled in configfs and continue to
generate it if so.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230130105045.120886-4-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The f_uvc code defines an endpoint named "uvc_control_ep" but it
is configured with a non-zero endpoint address and has its
bmAttributes flagged as USB_ENDPOINT_XFER_INT - this cannot be the
VideoControl interface's control endpoint, as the default endpoint
0 is used for that purpose. This is instead the optional interrupt
endpoint that can be contained by a VideoControl interface. There
is also a Class-specific VC Interrupt Endpoint Descriptor and a
SuperSpeed companion descriptor that are also for the VC interface's
interrupt endpoint but are named as though they are for the control
endpoint.

Rename the variables to make that clear.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230130105045.120886-2-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Setup function uvc_function_setup permits control transfer
requests with up to 64 bytes of payload (UVC_MAX_REQUEST_SIZE),
data stage handler for OUT transfer uses memcpy to copy req->actual
bytes to uvc_event->data.data array of size 60. This may result
in an overflow of 4 bytes.

Fixes: cdda479f15cd ("USB gadget: video class function driver")
Cc: stable <stable@kernel.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Signed-off-by: Szymon Heidrich <szymon.heidrich@gmail.com>
Link: https://lore.kernel.org/r/20221206141301.51305-1-szymon.heidrich@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

For the userspace it is needed to distinguish between requests for the
control or streaming interface. The userspace would have to parse the
configfs to know which interface index it has to compare the ctrl
requests against. Since the interface numbers are not fixed, e.g. for
composite gadgets, the interface offset depends on the setup.

The kernel has this information when handing over the ctrl request to
the userspace. This patch removes the offset from the interface numbers
and expose the default interface defines in the uapi g_uvc.h.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20221011075348.1786897-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

With the patch "588b9e85609b (usb: gadget: uvc: add v4l2 enumeration api
calls)" the driver is keeping a list of configfs entries currently
configured. The list is used in uvc_v4l2 on runtime.

The driver now is giving back the list item just after it was referenced
with config_item_put. It also calls config_item_put on uvc_free, which
is the only and right place to give back the reference. This patch fixes
the issue by removing the extra config_item_put in uvc_alloc.

Fixes: 588b9e85609b (usb: gadget: uvc: add v4l2 enumeration api calls)
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220930122839.1747279-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>