usb:gadget:uvc Do not use worker thread to pump isoc usb requests

When we use an async work queue to perform the function of pumping
usb requests to the usb controller, it is possible that amongst other
factors, thread scheduling affects at what cadence we're able to pump
requests. This could mean isoc usb requests miss their uframes - resulting
in video stream flickers on the host device.

To avoid this, we make the async_wq thread only produce isoc usb_requests
with uvc buffers encoded into them. The process of queueing to the
endpoint is done by the uvc_video_complete() handler. In case no
usb_requests are ready with encoded information, we just queue a zero
length request to the endpoint from the complete handler.

For bulk endpoints the async_wq thread still queues usb requests to the
endpoint.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>
Suggested-by: Avichal Rakesh <arakesh@google.com>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20231120062026.3759463-1-jchowdhary@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Fix use-after-free for inflight usb_requests

Currently, the uvc gadget driver allocates all uvc_requests as one array
and deallocates them all when the video stream stops. This includes
de-allocating all the usb_requests associated with those uvc_requests.
This can lead to use-after-free issues if any of those de-allocated
usb_requests were still owned by the usb controller.

This is patch 2 of 2 in fixing the use-after-free issue. It adds a new
flag to uvc_video to track when frames and requests should be flowing.
When disabling the video stream, the flag is tripped and, instead
of de-allocating all uvc_requests and usb_requests, the gadget
driver only de-allocates those usb_requests that are currently
owned by it (as present in req_free). Other usb_requests are left
untouched until their completion handler is called which takes care
of freeing the usb_request and its corresponding uvc_request.

Now that uvc_video does not depends on uvc->state, this patch removes
unnecessary upates to uvc->state that were made to accommodate uvc_video
logic. This should ensure that uvc gadget driver never accidentally
de-allocates a usb_request that it doesn't own.

Link: https://lore.kernel.org/7cd81649-2795-45b6-8c10-b7df1055020d@google.com
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Suggested-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Tested-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Avichal Rakesh <arakesh@google.com>
Link: https://lore.kernel.org/r/20231109004104.3467968-4-arakesh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Allocate uvc_requests one at a time

Currently, the uvc gadget driver allocates all uvc_requests as one array
and deallocates them all when the video stream stops. This includes
de-allocating all the usb_requests associated with those uvc_requests.
This can lead to use-after-free issues if any of those de-allocated
usb_requests were still owned by the usb controller.

This patch is 1 of 2 patches addressing the use-after-free issue.
Instead of bulk allocating all uvc_requests as an array, this patch
allocates uvc_requests one at a time, which should allows for similar
granularity when deallocating the uvc_requests. This patch has no
functional changes other than allocating each uvc_request separately,
and similarly freeing each of them separately.

Link: https://lore.kernel.org/7cd81649-2795-45b6-8c10-b7df1055020d@google.com
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Suggested-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Tested-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Avichal Rakesh <arakesh@google.com>
Link: https://lore.kernel.org/r/20231109004104.3467968-2-arakesh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: prevent use of disabled endpoint

Currently the set_alt callback immediately disables the endpoint and queues
the v4l2 streamoff event. However, as the streamoff event is processed
asynchronously, it is possible that the video_pump thread attempts to queue
requests to an already disabled endpoint.

This change moves disabling usb endpoint to the end of streamoff event
callback. As the endpoint's state can no longer be used, video_pump is
now guarded by uvc->state as well. To be consistent with the actual
streaming state, uvc->state is now toggled between CONNECTED and STREAMING
from the v4l2 event callback only.

Link: https://lore.kernel.org/20230615171558.GK741@pendragon.ideasonboard.com/
Link: https://lore.kernel.org/20230531085544.253363-1-dan.scally@ideasonboard.com/
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Reviewed-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Tested-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Avichal Rakesh <arakesh@google.com>
Link: https://lore.kernel.org/r/20231109004104.3467968-1-arakesh@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: function: Remove unused declarations

These declarations are not implemented anymore, remove them.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230818124025.51576-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: Copy XU descriptors during .bind()

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>

usb: gadget: uvc: Disable interrupt endpoint by default

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>

usb: gadget: uvc: Rename uvc_control_ep

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>

usb: gadget: uvc: add v4l2 enumeration api calls

This patch adds support to the v4l2 VIDIOCs for enum_format,
enum_framesizes and enum_frameintervals. This way, the userspace
application can use these VIDIOCS to query the via configfs exported
frame capabilities. With thes callbacks the userspace doesn't have to
bring its own configfs parser.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220909221335.15033-4-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: increase worker prio to WQ_HIGHPRI

This patch is changing the simple workqueue in the gadget driver to be
allocated as async_wq with a higher priority. The pump worker, that is
filling the usb requests, will have a higher priority and will not be
scheduled away so often while the video stream is handled. This will
lead to fewer streaming underruns.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220907215818.2670097-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: giveback vb2 buffer on req complete

On uvc_video_encode_isoc_sg the mapped vb2 buffer is returned
to early. Only after the last usb_request worked with the buffer
it is allowed to give it back to vb2. This patch fixes that.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20220402232744.3622565-3-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: allow for application to cleanly shutdown

Several types of kernel panics can occur due to timing during the uvc
gadget removal. This appears to be a problem with gadget resources being
managed by both the client application's v4l2 open/close and the UDC
gadget bind/unbind. Since the concept of USB_GADGET_DELAYED_STATUS
doesn't exist for unbind, add a wait to allow for the application to
close out.

Some examples of the panics that can occur are:

<1>[ 1147.652313] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000028
<4>[ 1147.652510] Call trace:
<4>[ 1147.652514] usb_gadget_disconnect+0x74/0x1f0
<4>[ 1147.652516] usb_gadget_deactivate+0x38/0x168
<4>[ 1147.652520] usb_function_deactivate+0x54/0x90
<4>[ 1147.652524] uvc_function_disconnect+0x14/0x38
<4>[ 1147.652527] uvc_v4l2_release+0x34/0xa0
<4>[ 1147.652537] __fput+0xdc/0x2c0
<4>[ 1147.652540] ____fput+0x10/0x1c
<4>[ 1147.652545] task_work_run+0xe4/0x12c
<4>[ 1147.652549] do_notify_resume+0x108/0x168

<1>[ 282.950561][ T1472] Unable to handle kernel NULL pointer
dereference at virtual address 00000000000005b8
<6>[ 282.953111][ T1472] Call trace:
<6>[ 282.953121][ T1472] usb_function_deactivate+0x54/0xd4
<6>[ 282.953134][ T1472] uvc_v4l2_release+0xac/0x1e4
<6>[ 282.953145][ T1472] v4l2_release+0x134/0x1f0
<6>[ 282.953167][ T1472] __fput+0xf4/0x428
<6>[ 282.953178][ T1472] ____fput+0x14/0x24
<6>[ 282.953193][ T1472] task_work_run+0xac/0x130

<3>[ 213.410077][ T29] configfs-gadget gadget: uvc: Failed to queue
request (-108).
<1>[ 213.410116][ T29] Unable to handle kernel NULL pointer
dereference at virtual address 0000000000000003
<6>[ 213.413460][ T29] Call trace:
<6>[ 213.413474][ T29] uvcg_video_pump+0x1f0/0x384
<6>[ 213.413489][ T29] process_one_work+0x2a4/0x544
<6>[ 213.413502][ T29] worker_thread+0x350/0x784
<6>[ 213.413515][ T29] kthread+0x2ac/0x320
<6>[ 213.413528][ T29] ret_from_fork+0x10/0x30

Signed-off-by: Dan Vacura <w36195@motorola.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20220503201039.71720-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: implement dwPresentationTime and scrSourceClock

This patch adds the fields UVC_STREAM_PTS and UVC_STREAM_SCR to the uvc
header, in case this data is available. It also enables the copy of the
timestamp to the vb2_v4l2_buffer by setting V4L2_BUF_FLAG_TIMESTAMP_COPY
in the queue.timestamp_flags.

Signed-off-by: Michael Olbrich <m.olbrich@pengutronix.de>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20211022093223.26493-2-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: consistently use define for headerlen

The uvc request headerlen of 2 was defined as UVCG_REQUEST_HEADER_LEN
in commit e81e7f9a0eb9 ("usb: gadget: uvc: add scatter gather support").
We missed to use it consistently. This patch fixes that.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20211018072059.11465-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

usb: gadget: uvc: fix multiple opens

Currently, the UVC function is activated when open on the corresponding
v4l2 device is called. On another open the activation of the function
fails since the deactivation counter in `usb_function_activate` equals
0. However the error is not returned to userspace since the open of the
v4l2 device is successful.

On a close the function is deactivated (since deactivation counter still
equals 0) and the video is disabled in `uvc_v4l2_release`, although the
UVC application potentially is streaming.

Move activation of UVC function to subscription on UVC_EVENT_SETUP
because there we can guarantee for a userspace application utilizing
UVC. Block subscription on UVC_EVENT_SETUP while another application
already is subscribed to it, indicated by `bool func_connected` in
`struct uvc_device`. Extend the `struct uvc_file_handle` with member
`bool is_uvc_app_handle` to tag it as the handle used by the userspace
UVC application.

With this a process is able to check capabilities of the v4l2 device
without deactivating the function for the actual UVC application.

Reviewed-By: Michael Tretter <m.tretter@pengutronix.de>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Thomas Haemmerle <thomas.haemmerle@wolfvision.net>
Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Link: https://lore.kernel.org/r/20211003201355.24081-1-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: decrease the interrupt load to a quarter

With usb3 we handle many more requests. Decrease the interrupt load by
only enabling the interrupt every quarter of the allocated requests.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>

--
v1 -> v2: - edited patch description
- removed extra parantheses
- added a comment for the logic
- using unsigned int instead of int
- reinitializing req_int_count in uvcg_video_enable
v2 -> v3: -
Link: https://lore.kernel.org/r/20210628155311.16762-6-m.grzeschik@pengutronix.de

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: add scatter gather support

This patch adds support for scatter gather transfers. If the underlying
gadgets sg_supported == true, then the videeobuf2-dma-sg is used and the
encode routine maps all scatter entries to separate scatterlists for the
usb gadget.

When streaming 1080p with request size of 1024 times 3 bytes top shows a
difference of about 6.4% CPU load applying this patch:

PID USER PR NI VIRT RES %CPU %MEM TIME+ S COMMAND

64 root 0 -20 0.0m 0.0m 7.7 0.0 0:01.25 I [kworker/u5:0-uvcvideo]
83 root 0 -20 0.0m 0.0m 4.5 0.0 0:03.71 I [kworker/u5:3-uvcvideo]
307 root -51 0 0.0m 0.0m 3.8 0.0 0:01.05 S [irq/51-dwc3]

vs.

64 root 0 -20 0.0m 0.0m 5.8 0.0 0:01.79 I [kworker/u5:0-uvcvideo]
306 root -51 0 0.0m 0.0m 3.2 0.0 0:01.97 S [irq/51-dwc3]
82 root 0 -20 0.0m 0.0m 0.6 0.0 0:01.86 I [kworker/u5:1-uvcvideo]

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20210628155311.16762-5-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc: make uvc_num_requests depend on gadget speed

While sending bigger images is possible with USB_SPEED_SUPER it is
better to use more isochronous requests in flight. This patch makes the
number uvc_num_requests dynamic by changing it depending on the gadget
speed.

Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20210628155311.16762-3-m.grzeschik@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: uvc_video: add worker to handle the frame pumping

This patch changes the function uvc_video_pump to be a separate
scheduled worker. This way the completion handler of each usb request
and every direct caller of the pump has only to schedule the worker
instead of doing the request handling by itself.

Moving the request handling to one thread solves the locking problems
between the three queueing cases in the completion handler, v4l2_qbuf
and video_enable.

Many drivers handle the completion handlers directly in their interrupt
handlers. This patch also reduces the workload on each interrupt.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

USB: gadget: Use the correct style for SPDX License Identifier

This patch corrects the SPDX License Identifier style in
header files related to USB peripheral controller drivers.
For C header files Documentation/process/license-rules.rst
mandates C-like comments (opposed to C source files where
C++ style should be used).

Changes made by using a script provided by Joe Perches here:
https://lkml.org/lkml/2019/2/7/46.

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: uvc: add uvcg_warn macro

We only have uvcg_dbg, uvcg_info, and uvcg_err, so add uvcg_warn macro
to print gadget device name and function name along with format.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: uvc: Replace plain printk() with dev_*()

Adding device context to the kernel log messages make them more useful.
Add new uvcg_* macros based on dev_*() that print both the gadget device
name and the function name.

While at it, remove a commented out printk statement and an unused
printk-based macro.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Tested-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

usb: gadget: uvc: Minimize #include in headers

In order to speed up compilation, only include the headers that are
strictly required within other headers. To that end, use forward
structure declaration and move #include statements to .c file as
appropriate.

While at it, sort headers alphabetically, and remove unneeded __KERNEL__
guards.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: uvc: Move userspace API definition to public header

The UVC gadget userspace API (V4L2 events and custom ioctls) is defined
in a header internal to the kernel. Move it to a new public header to
make it accessible to userspace.

The UVC_INTF_CONTROL and UVC_INTF_STREAMING macros are not used, so
remove them in the process.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

USB: gadget: function: Remove redundant license text

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner. So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text. And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Oliver Neukum <oneukum@suse.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jerry Zhang <zhangjerry@google.com>
Cc: John Keeping <john@metanate.com>
Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Abdulhadi Mohamed <abdulahhadi2@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Janusz Dziedzic <januszx.dziedzic@linux.intel.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Fix checkpatch error for braces

Fix error message by checkpath.pl
open brace '{' following struct/enum go on the same line

Patch applied by running fix inplace capability of checkpatch:
checkpatch.pl -f *.[ch] --types OPEN_BRACE --fix-inplace

Signed-off-by: Anson Jacob <ansonjacob.aj@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: uvc: remove unused including <linux/version.h>

Remove including <linux/version.h> that don't need it.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

[media] gadget/uvc: embed video_device

Embed the video_device struct to simplify the error handling and in
order to (eventually) get rid of video_device_alloc/release.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[media] uvc gadget: switch to v4l2 core locking

Switch this driver over to the V4L2 core locking mechanism in preparation
for switching to unlocked_ioctl. Suggested by Laurent Pinchart.

This patch introduces a new mutex at the struct uvc_video level and
drops the old mutex at the queue level. The new lock is now used for all
ioctl locking and in the release file operation (the driver always has
to take care of locking in file operations, the core only serializes
ioctls).

Note that the mmap and get_unmapped_area file operations no longer take
a lock. Commit f035eb4e976ef5a059e30bc91cfd310ff030a7d3 fixed a AB-BA
deadlock by moving all the locking down into vb2, so the mmap and
get_unmapped_area file operations should no longer do any locking before
calling into vb2.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

usb: gadget: uvc: separately compile some components of f_uvc

Compile uvc_queue, uvc_v4l2, uvc_video separately so that later they can
be all combined in a separately compiled f_uvc.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Tested-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
[Make uvc_v4l2_ioctl_ops non-static]
[Rename __UVC__V4L2__H__ and __UVC__VIDEO__H__]
[Update MAINTAINERS]
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: uvc: remove DRIVER_VERSION{,_NUMBER}

As the driver is in mainline we can remove the version numbers.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: Gadget directory cleanup - group usb functions

The drivers/usb/gadget directory contains many files.
Files which are related can be distributed into separate directories.
This patch moves the USB functions implementations into a separate directory.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>