Files
android_kernel_xiaomi_sm8450/drivers/usb/gadget/function/uvc_v4l2.c
Thomas Haemmerle 518c3f98e5 usb: gadget: uvc: fix multiple opens
commit 72ee48ee8925446eaeda8e4ef3f2eb16b4a93d2a upstream.

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
Cc: Dan Vacura <W36195@motorola.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-12-14 11:32:33 +01:00

399 lines
9.7 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* uvc_v4l2.c -- USB Video Class Gadget driver
*
* Copyright (C) 2009-2010
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*/
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/usb/g_uvc.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <media/v4l2-dev.h>
#include <media/v4l2-event.h>
#include <media/v4l2-ioctl.h>
#include "f_uvc.h"
#include "uvc.h"
#include "uvc_queue.h"
#include "uvc_video.h"
#include "uvc_v4l2.h"
/* --------------------------------------------------------------------------
* Requests handling
*/
static int
uvc_send_response(struct uvc_device *uvc, struct uvc_request_data *data)
{
struct usb_composite_dev *cdev = uvc->func.config->cdev;
struct usb_request *req = uvc->control_req;
if (data->length < 0)
return usb_ep_set_halt(cdev->gadget->ep0);
req->length = min_t(unsigned int, uvc->event_length, data->length);
req->zero = data->length < uvc->event_length;
memcpy(req->buf, data->data, req->length);
return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
}
/* --------------------------------------------------------------------------
* V4L2 ioctls
*/
struct uvc_format {
u8 bpp;
u32 fcc;
};
static struct uvc_format uvc_formats[] = {
{ 16, V4L2_PIX_FMT_YUYV },
{ 0, V4L2_PIX_FMT_MJPEG },
};
static int
uvc_v4l2_querycap(struct file *file, void *fh, struct v4l2_capability *cap)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct usb_composite_dev *cdev = uvc->func.config->cdev;
strlcpy(cap->driver, "g_uvc", sizeof(cap->driver));
strlcpy(cap->card, cdev->gadget->name, sizeof(cap->card));
strlcpy(cap->bus_info, dev_name(&cdev->gadget->dev),
sizeof(cap->bus_info));
return 0;
}
static int
uvc_v4l2_get_format(struct file *file, void *fh, struct v4l2_format *fmt)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
fmt->fmt.pix.pixelformat = video->fcc;
fmt->fmt.pix.width = video->width;
fmt->fmt.pix.height = video->height;
fmt->fmt.pix.field = V4L2_FIELD_NONE;
fmt->fmt.pix.bytesperline = video->bpp * video->width / 8;
fmt->fmt.pix.sizeimage = video->imagesize;
fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
fmt->fmt.pix.priv = 0;
return 0;
}
static int
uvc_v4l2_set_format(struct file *file, void *fh, struct v4l2_format *fmt)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
struct uvc_format *format;
unsigned int imagesize;
unsigned int bpl;
unsigned int i;
for (i = 0; i < ARRAY_SIZE(uvc_formats); ++i) {
format = &uvc_formats[i];
if (format->fcc == fmt->fmt.pix.pixelformat)
break;
}
if (i == ARRAY_SIZE(uvc_formats)) {
uvcg_info(&uvc->func, "Unsupported format 0x%08x.\n",
fmt->fmt.pix.pixelformat);
return -EINVAL;
}
bpl = format->bpp * fmt->fmt.pix.width / 8;
imagesize = bpl ? bpl * fmt->fmt.pix.height : fmt->fmt.pix.sizeimage;
video->fcc = format->fcc;
video->bpp = format->bpp;
video->width = fmt->fmt.pix.width;
video->height = fmt->fmt.pix.height;
video->imagesize = imagesize;
fmt->fmt.pix.field = V4L2_FIELD_NONE;
fmt->fmt.pix.bytesperline = bpl;
fmt->fmt.pix.sizeimage = imagesize;
fmt->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
fmt->fmt.pix.priv = 0;
return 0;
}
static int
uvc_v4l2_reqbufs(struct file *file, void *fh, struct v4l2_requestbuffers *b)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
if (b->type != video->queue.queue.type)
return -EINVAL;
return uvcg_alloc_buffers(&video->queue, b);
}
static int
uvc_v4l2_querybuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
return uvcg_query_buffer(&video->queue, b);
}
static int
uvc_v4l2_qbuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
int ret;
ret = uvcg_queue_buffer(&video->queue, b);
if (ret < 0)
return ret;
schedule_work(&video->pump);
return ret;
}
static int
uvc_v4l2_dqbuf(struct file *file, void *fh, struct v4l2_buffer *b)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
return uvcg_dequeue_buffer(&video->queue, b, file->f_flags & O_NONBLOCK);
}
static int
uvc_v4l2_streamon(struct file *file, void *fh, enum v4l2_buf_type type)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
int ret;
if (type != video->queue.queue.type)
return -EINVAL;
/* Enable UVC video. */
ret = uvcg_video_enable(video, 1);
if (ret < 0)
return ret;
/*
* Complete the alternate setting selection setup phase now that
* userspace is ready to provide video frames.
*/
uvc_function_setup_continue(uvc);
uvc->state = UVC_STATE_STREAMING;
return 0;
}
static int
uvc_v4l2_streamoff(struct file *file, void *fh, enum v4l2_buf_type type)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_video *video = &uvc->video;
if (type != video->queue.queue.type)
return -EINVAL;
return uvcg_video_enable(video, 0);
}
static int
uvc_v4l2_subscribe_event(struct v4l2_fh *fh,
const struct v4l2_event_subscription *sub)
{
struct uvc_device *uvc = video_get_drvdata(fh->vdev);
struct uvc_file_handle *handle = to_uvc_file_handle(fh);
int ret;
if (sub->type < UVC_EVENT_FIRST || sub->type > UVC_EVENT_LAST)
return -EINVAL;
if (sub->type == UVC_EVENT_SETUP && uvc->func_connected)
return -EBUSY;
ret = v4l2_event_subscribe(fh, sub, 2, NULL);
if (ret < 0)
return ret;
if (sub->type == UVC_EVENT_SETUP) {
uvc->func_connected = true;
handle->is_uvc_app_handle = true;
uvc_function_connect(uvc);
}
return 0;
}
static void uvc_v4l2_disable(struct uvc_device *uvc)
{
uvc->func_connected = false;
uvc_function_disconnect(uvc);
uvcg_video_enable(&uvc->video, 0);
uvcg_free_buffers(&uvc->video.queue);
}
static int
uvc_v4l2_unsubscribe_event(struct v4l2_fh *fh,
const struct v4l2_event_subscription *sub)
{
struct uvc_device *uvc = video_get_drvdata(fh->vdev);
struct uvc_file_handle *handle = to_uvc_file_handle(fh);
int ret;
ret = v4l2_event_unsubscribe(fh, sub);
if (ret < 0)
return ret;
if (sub->type == UVC_EVENT_SETUP && handle->is_uvc_app_handle) {
uvc_v4l2_disable(uvc);
handle->is_uvc_app_handle = false;
}
return 0;
}
static long
uvc_v4l2_ioctl_default(struct file *file, void *fh, bool valid_prio,
unsigned int cmd, void *arg)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
switch (cmd) {
case UVCIOC_SEND_RESPONSE:
return uvc_send_response(uvc, arg);
default:
return -ENOIOCTLCMD;
}
}
const struct v4l2_ioctl_ops uvc_v4l2_ioctl_ops = {
.vidioc_querycap = uvc_v4l2_querycap,
.vidioc_g_fmt_vid_out = uvc_v4l2_get_format,
.vidioc_s_fmt_vid_out = uvc_v4l2_set_format,
.vidioc_reqbufs = uvc_v4l2_reqbufs,
.vidioc_querybuf = uvc_v4l2_querybuf,
.vidioc_qbuf = uvc_v4l2_qbuf,
.vidioc_dqbuf = uvc_v4l2_dqbuf,
.vidioc_streamon = uvc_v4l2_streamon,
.vidioc_streamoff = uvc_v4l2_streamoff,
.vidioc_subscribe_event = uvc_v4l2_subscribe_event,
.vidioc_unsubscribe_event = uvc_v4l2_unsubscribe_event,
.vidioc_default = uvc_v4l2_ioctl_default,
};
/* --------------------------------------------------------------------------
* V4L2
*/
static int
uvc_v4l2_open(struct file *file)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_file_handle *handle;
handle = kzalloc(sizeof(*handle), GFP_KERNEL);
if (handle == NULL)
return -ENOMEM;
v4l2_fh_init(&handle->vfh, vdev);
v4l2_fh_add(&handle->vfh);
handle->device = &uvc->video;
file->private_data = &handle->vfh;
return 0;
}
static int
uvc_v4l2_release(struct file *file)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_file_handle *handle = to_uvc_file_handle(file->private_data);
struct uvc_video *video = handle->device;
mutex_lock(&video->mutex);
if (handle->is_uvc_app_handle)
uvc_v4l2_disable(uvc);
mutex_unlock(&video->mutex);
file->private_data = NULL;
v4l2_fh_del(&handle->vfh);
v4l2_fh_exit(&handle->vfh);
kfree(handle);
return 0;
}
static int
uvc_v4l2_mmap(struct file *file, struct vm_area_struct *vma)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
return uvcg_queue_mmap(&uvc->video.queue, vma);
}
static __poll_t
uvc_v4l2_poll(struct file *file, poll_table *wait)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
return uvcg_queue_poll(&uvc->video.queue, file, wait);
}
#ifndef CONFIG_MMU
static unsigned long uvcg_v4l2_get_unmapped_area(struct file *file,
unsigned long addr, unsigned long len, unsigned long pgoff,
unsigned long flags)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
return uvcg_queue_get_unmapped_area(&uvc->video.queue, pgoff);
}
#endif
const struct v4l2_file_operations uvc_v4l2_fops = {
.owner = THIS_MODULE,
.open = uvc_v4l2_open,
.release = uvc_v4l2_release,
.unlocked_ioctl = video_ioctl2,
.mmap = uvc_v4l2_mmap,
.poll = uvc_v4l2_poll,
#ifndef CONFIG_MMU
.get_unmapped_area = uvcg_v4l2_get_unmapped_area,
#endif
};