kernel-ark/drivers/usb/gadget/uvc_v4l2.c
Laurent Pinchart cdda479f15 USB gadget: video class function driver
This USB video class function driver implements a video capture device from the
host's point of view. It creates a V4L2 output device on the gadget's side to
transfer data from a userspace application over USB.

The UVC-specific descriptors are passed by the gadget driver to the UVC
function driver, making them completely configurable without any modification
to the function's driver code.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-20 13:21:41 -07:00

375 lines
8.3 KiB
C

/*
* uvc_v4l2.c -- USB Video Class Gadget driver
*
* Copyright (C) 2009-2010
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
*/
#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/version.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 "uvc.h"
#include "uvc_queue.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(uvc->event_length, data->length);
req->zero = data->length < uvc->event_length;
req->dma = DMA_ADDR_INVALID;
memcpy(req->buf, data->data, data->length);
return usb_ep_queue(cdev->gadget->ep0, req, GFP_KERNEL);
}
/* --------------------------------------------------------------------------
* V4L2
*/
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_get_format(struct uvc_video *video, struct v4l2_format *fmt)
{
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 uvc_video *video, struct v4l2_format *fmt)
{
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 (format == NULL || format->fcc != fmt->fmt.pix.pixelformat) {
printk(KERN_INFO "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_open(struct file *file)
{
struct video_device *vdev = video_devdata(file);
struct uvc_device *uvc = video_get_drvdata(vdev);
struct uvc_file_handle *handle;
int ret;
handle = kzalloc(sizeof(*handle), GFP_KERNEL);
if (handle == NULL)
return -ENOMEM;
ret = v4l2_fh_init(&handle->vfh, vdev);
if (ret < 0)
goto error;
ret = v4l2_event_init(&handle->vfh);
if (ret < 0)
goto error;
ret = v4l2_event_alloc(&handle->vfh, 8);
if (ret < 0)
goto error;
v4l2_fh_add(&handle->vfh);
handle->device = &uvc->video;
file->private_data = &handle->vfh;
uvc_function_connect(uvc);
return 0;
error:
v4l2_fh_exit(&handle->vfh);
return ret;
}
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;
uvc_function_disconnect(uvc);
uvc_video_enable(video, 0);
mutex_lock(&video->queue.mutex);
if (uvc_free_buffers(&video->queue) < 0)
printk(KERN_ERR "uvc_v4l2_release: Unable to free "
"buffers.\n");
mutex_unlock(&video->queue.mutex);
file->private_data = NULL;
v4l2_fh_del(&handle->vfh);
v4l2_fh_exit(&handle->vfh);
kfree(handle);
return 0;
}
static long
uvc_v4l2_do_ioctl(struct file *file, unsigned int cmd, void *arg)
{
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 usb_composite_dev *cdev = uvc->func.config->cdev;
struct uvc_video *video = &uvc->video;
int ret = 0;
switch (cmd) {
/* Query capabilities */
case VIDIOC_QUERYCAP:
{
struct v4l2_capability *cap = arg;
memset(cap, 0, sizeof *cap);
strncpy(cap->driver, "g_uvc", sizeof(cap->driver));
strncpy(cap->card, cdev->gadget->name, sizeof(cap->card));
strncpy(cap->bus_info, dev_name(&cdev->gadget->dev),
sizeof cap->bus_info);
cap->version = DRIVER_VERSION_NUMBER;
cap->capabilities = V4L2_CAP_VIDEO_OUTPUT | V4L2_CAP_STREAMING;
break;
}
/* Get & Set format */
case VIDIOC_G_FMT:
{
struct v4l2_format *fmt = arg;
if (fmt->type != video->queue.type)
return -EINVAL;
return uvc_v4l2_get_format(video, fmt);
}
case VIDIOC_S_FMT:
{
struct v4l2_format *fmt = arg;
if (fmt->type != video->queue.type)
return -EINVAL;
return uvc_v4l2_set_format(video, fmt);
}
/* Buffers & streaming */
case VIDIOC_REQBUFS:
{
struct v4l2_requestbuffers *rb = arg;
if (rb->type != video->queue.type ||
rb->memory != V4L2_MEMORY_MMAP)
return -EINVAL;
ret = uvc_alloc_buffers(&video->queue, rb->count,
video->imagesize);
if (ret < 0)
return ret;
rb->count = ret;
ret = 0;
break;
}
case VIDIOC_QUERYBUF:
{
struct v4l2_buffer *buf = arg;
if (buf->type != video->queue.type)
return -EINVAL;
return uvc_query_buffer(&video->queue, buf);
}
case VIDIOC_QBUF:
if ((ret = uvc_queue_buffer(&video->queue, arg)) < 0)
return ret;
return uvc_video_pump(video);
case VIDIOC_DQBUF:
return uvc_dequeue_buffer(&video->queue, arg,
file->f_flags & O_NONBLOCK);
case VIDIOC_STREAMON:
{
int *type = arg;
if (*type != video->queue.type)
return -EINVAL;
return uvc_video_enable(video, 1);
}
case VIDIOC_STREAMOFF:
{
int *type = arg;
if (*type != video->queue.type)
return -EINVAL;
return uvc_video_enable(video, 0);
}
/* Events */
case VIDIOC_DQEVENT:
{
struct v4l2_event *event = arg;
ret = v4l2_event_dequeue(&handle->vfh, event,
file->f_flags & O_NONBLOCK);
if (ret == 0 && event->type == UVC_EVENT_SETUP) {
struct uvc_event *uvc_event = (void *)&event->u.data;
/* Tell the complete callback to generate an event for
* the next request that will be enqueued by
* uvc_event_write.
*/
uvc->event_setup_out =
!(uvc_event->req.bRequestType & USB_DIR_IN);
uvc->event_length = uvc_event->req.wLength;
}
return ret;
}
case VIDIOC_SUBSCRIBE_EVENT:
{
struct v4l2_event_subscription *sub = arg;
if (sub->type < UVC_EVENT_FIRST || sub->type > UVC_EVENT_LAST)
return -EINVAL;
return v4l2_event_subscribe(&handle->vfh, arg);
}
case VIDIOC_UNSUBSCRIBE_EVENT:
return v4l2_event_unsubscribe(&handle->vfh, arg);
case UVCIOC_SEND_RESPONSE:
ret = uvc_send_response(uvc, arg);
break;
default:
return -ENOIOCTLCMD;
}
return ret;
}
static long
uvc_v4l2_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
return video_usercopy(file, cmd, arg, uvc_v4l2_do_ioctl);
}
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 uvc_queue_mmap(&uvc->video.queue, vma);
}
static unsigned int
uvc_v4l2_poll(struct file *file, poll_table *wait)
{
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);
unsigned int mask = 0;
poll_wait(file, &handle->vfh.events->wait, wait);
if (v4l2_event_pending(&handle->vfh))
mask |= POLLPRI;
mask |= uvc_queue_poll(&uvc->video.queue, file, wait);
return mask;
}
struct v4l2_file_operations uvc_v4l2_fops = {
.owner = THIS_MODULE,
.open = uvc_v4l2_open,
.release = uvc_v4l2_release,
.ioctl = uvc_v4l2_ioctl,
.mmap = uvc_v4l2_mmap,
.poll = uvc_v4l2_poll,
};