411 строки
9.7 KiB
C
411 строки
9.7 KiB
C
// SPDX-License-Identifier: GPL-2.0+
|
|
/*
|
|
* uvc_video.c -- USB Video Class Gadget driver
|
|
*
|
|
* Copyright (C) 2009-2010
|
|
* Laurent Pinchart (laurent.pinchart@ideasonboard.com)
|
|
*/
|
|
|
|
#include <linux/kernel.h>
|
|
#include <linux/device.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/usb/ch9.h>
|
|
#include <linux/usb/gadget.h>
|
|
#include <linux/usb/video.h>
|
|
|
|
#include <media/v4l2-dev.h>
|
|
|
|
#include "uvc.h"
|
|
#include "uvc_queue.h"
|
|
#include "uvc_video.h"
|
|
|
|
/* --------------------------------------------------------------------------
|
|
* Video codecs
|
|
*/
|
|
|
|
static int
|
|
uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf,
|
|
u8 *data, int len)
|
|
{
|
|
data[0] = 2;
|
|
data[1] = UVC_STREAM_EOH | video->fid;
|
|
|
|
if (buf->bytesused - video->queue.buf_used <= len - 2)
|
|
data[1] |= UVC_STREAM_EOF;
|
|
|
|
return 2;
|
|
}
|
|
|
|
static int
|
|
uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf,
|
|
u8 *data, int len)
|
|
{
|
|
struct uvc_video_queue *queue = &video->queue;
|
|
unsigned int nbytes;
|
|
void *mem;
|
|
|
|
/* Copy video data to the USB buffer. */
|
|
mem = buf->mem + queue->buf_used;
|
|
nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
|
|
|
|
memcpy(data, mem, nbytes);
|
|
queue->buf_used += nbytes;
|
|
|
|
return nbytes;
|
|
}
|
|
|
|
static void
|
|
uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
|
|
struct uvc_buffer *buf)
|
|
{
|
|
void *mem = req->buf;
|
|
int len = video->req_size;
|
|
int ret;
|
|
|
|
/* Add a header at the beginning of the payload. */
|
|
if (video->payload_size == 0) {
|
|
ret = uvc_video_encode_header(video, buf, mem, len);
|
|
video->payload_size += ret;
|
|
mem += ret;
|
|
len -= ret;
|
|
}
|
|
|
|
/* Process video data. */
|
|
len = min((int)(video->max_payload_size - video->payload_size), len);
|
|
ret = uvc_video_encode_data(video, buf, mem, len);
|
|
|
|
video->payload_size += ret;
|
|
len -= ret;
|
|
|
|
req->length = video->req_size - len;
|
|
req->zero = video->payload_size == video->max_payload_size;
|
|
|
|
if (buf->bytesused == video->queue.buf_used) {
|
|
video->queue.buf_used = 0;
|
|
buf->state = UVC_BUF_STATE_DONE;
|
|
uvcg_queue_next_buffer(&video->queue, buf);
|
|
video->fid ^= UVC_STREAM_FID;
|
|
|
|
video->payload_size = 0;
|
|
}
|
|
|
|
if (video->payload_size == video->max_payload_size ||
|
|
buf->bytesused == video->queue.buf_used)
|
|
video->payload_size = 0;
|
|
}
|
|
|
|
static void
|
|
uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
|
|
struct uvc_buffer *buf)
|
|
{
|
|
void *mem = req->buf;
|
|
int len = video->req_size;
|
|
int ret;
|
|
|
|
/* Add the header. */
|
|
ret = uvc_video_encode_header(video, buf, mem, len);
|
|
mem += ret;
|
|
len -= ret;
|
|
|
|
/* Process video data. */
|
|
ret = uvc_video_encode_data(video, buf, mem, len);
|
|
len -= ret;
|
|
|
|
req->length = video->req_size - len;
|
|
|
|
if (buf->bytesused == video->queue.buf_used) {
|
|
video->queue.buf_used = 0;
|
|
buf->state = UVC_BUF_STATE_DONE;
|
|
uvcg_queue_next_buffer(&video->queue, buf);
|
|
video->fid ^= UVC_STREAM_FID;
|
|
}
|
|
}
|
|
|
|
/* --------------------------------------------------------------------------
|
|
* Request handling
|
|
*/
|
|
|
|
static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
|
|
{
|
|
int ret;
|
|
|
|
ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
|
|
if (ret < 0) {
|
|
uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
|
|
ret);
|
|
|
|
/* Isochronous endpoints can't be halted. */
|
|
if (usb_endpoint_xfer_bulk(video->ep->desc))
|
|
usb_ep_set_halt(video->ep);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* I somehow feel that synchronisation won't be easy to achieve here. We have
|
|
* three events that control USB requests submission:
|
|
*
|
|
* - USB request completion: the completion handler will resubmit the request
|
|
* if a video buffer is available.
|
|
*
|
|
* - USB interface setting selection: in response to a SET_INTERFACE request,
|
|
* the handler will start streaming if a video buffer is available and if
|
|
* video is not currently streaming.
|
|
*
|
|
* - V4L2 buffer queueing: the driver will start streaming if video is not
|
|
* currently streaming.
|
|
*
|
|
* Race conditions between those 3 events might lead to deadlocks or other
|
|
* nasty side effects.
|
|
*
|
|
* The "video currently streaming" condition can't be detected by the irqqueue
|
|
* being empty, as a request can still be in flight. A separate "queue paused"
|
|
* flag is thus needed.
|
|
*
|
|
* The paused flag will be set when we try to retrieve the irqqueue head if the
|
|
* queue is empty, and cleared when we queue a buffer.
|
|
*
|
|
* The USB request completion handler will get the buffer at the irqqueue head
|
|
* under protection of the queue spinlock. If the queue is empty, the streaming
|
|
* paused flag will be set. Right after releasing the spinlock a userspace
|
|
* application can queue a buffer. The flag will then cleared, and the ioctl
|
|
* handler will restart the video stream.
|
|
*/
|
|
static void
|
|
uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
|
|
{
|
|
struct uvc_video *video = req->context;
|
|
struct uvc_video_queue *queue = &video->queue;
|
|
struct uvc_buffer *buf;
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
switch (req->status) {
|
|
case 0:
|
|
break;
|
|
|
|
case -ESHUTDOWN: /* disconnect from host. */
|
|
uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");
|
|
uvcg_queue_cancel(queue, 1);
|
|
goto requeue;
|
|
|
|
default:
|
|
uvcg_info(&video->uvc->func,
|
|
"VS request completed with status %d.\n",
|
|
req->status);
|
|
uvcg_queue_cancel(queue, 0);
|
|
goto requeue;
|
|
}
|
|
|
|
spin_lock_irqsave(&video->queue.irqlock, flags);
|
|
buf = uvcg_queue_head(&video->queue);
|
|
if (buf == NULL) {
|
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
|
goto requeue;
|
|
}
|
|
|
|
video->encode(req, video, buf);
|
|
|
|
ret = uvcg_video_ep_queue(video, req);
|
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
|
|
|
if (ret < 0) {
|
|
uvcg_queue_cancel(queue, 0);
|
|
goto requeue;
|
|
}
|
|
|
|
return;
|
|
|
|
requeue:
|
|
spin_lock_irqsave(&video->req_lock, flags);
|
|
list_add_tail(&req->list, &video->req_free);
|
|
spin_unlock_irqrestore(&video->req_lock, flags);
|
|
}
|
|
|
|
static int
|
|
uvc_video_free_requests(struct uvc_video *video)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; i < UVC_NUM_REQUESTS; ++i) {
|
|
if (video->req[i]) {
|
|
usb_ep_free_request(video->ep, video->req[i]);
|
|
video->req[i] = NULL;
|
|
}
|
|
|
|
if (video->req_buffer[i]) {
|
|
kfree(video->req_buffer[i]);
|
|
video->req_buffer[i] = NULL;
|
|
}
|
|
}
|
|
|
|
INIT_LIST_HEAD(&video->req_free);
|
|
video->req_size = 0;
|
|
return 0;
|
|
}
|
|
|
|
static int
|
|
uvc_video_alloc_requests(struct uvc_video *video)
|
|
{
|
|
unsigned int req_size;
|
|
unsigned int i;
|
|
int ret = -ENOMEM;
|
|
|
|
BUG_ON(video->req_size);
|
|
|
|
req_size = video->ep->maxpacket
|
|
* max_t(unsigned int, video->ep->maxburst, 1)
|
|
* (video->ep->mult);
|
|
|
|
for (i = 0; i < UVC_NUM_REQUESTS; ++i) {
|
|
video->req_buffer[i] = kmalloc(req_size, GFP_KERNEL);
|
|
if (video->req_buffer[i] == NULL)
|
|
goto error;
|
|
|
|
video->req[i] = usb_ep_alloc_request(video->ep, GFP_KERNEL);
|
|
if (video->req[i] == NULL)
|
|
goto error;
|
|
|
|
video->req[i]->buf = video->req_buffer[i];
|
|
video->req[i]->length = 0;
|
|
video->req[i]->complete = uvc_video_complete;
|
|
video->req[i]->context = video;
|
|
|
|
list_add_tail(&video->req[i]->list, &video->req_free);
|
|
}
|
|
|
|
video->req_size = req_size;
|
|
|
|
return 0;
|
|
|
|
error:
|
|
uvc_video_free_requests(video);
|
|
return ret;
|
|
}
|
|
|
|
/* --------------------------------------------------------------------------
|
|
* Video streaming
|
|
*/
|
|
|
|
/*
|
|
* uvcg_video_pump - Pump video data into the USB requests
|
|
*
|
|
* This function fills the available USB requests (listed in req_free) with
|
|
* video data from the queued buffers.
|
|
*/
|
|
int uvcg_video_pump(struct uvc_video *video)
|
|
{
|
|
struct uvc_video_queue *queue = &video->queue;
|
|
struct usb_request *req;
|
|
struct uvc_buffer *buf;
|
|
unsigned long flags;
|
|
int ret;
|
|
|
|
/* FIXME TODO Race between uvcg_video_pump and requests completion
|
|
* handler ???
|
|
*/
|
|
|
|
while (1) {
|
|
/* Retrieve the first available USB request, protected by the
|
|
* request lock.
|
|
*/
|
|
spin_lock_irqsave(&video->req_lock, flags);
|
|
if (list_empty(&video->req_free)) {
|
|
spin_unlock_irqrestore(&video->req_lock, flags);
|
|
return 0;
|
|
}
|
|
req = list_first_entry(&video->req_free, struct usb_request,
|
|
list);
|
|
list_del(&req->list);
|
|
spin_unlock_irqrestore(&video->req_lock, flags);
|
|
|
|
/* Retrieve the first available video buffer and fill the
|
|
* request, protected by the video queue irqlock.
|
|
*/
|
|
spin_lock_irqsave(&queue->irqlock, flags);
|
|
buf = uvcg_queue_head(queue);
|
|
if (buf == NULL) {
|
|
spin_unlock_irqrestore(&queue->irqlock, flags);
|
|
break;
|
|
}
|
|
|
|
video->encode(req, video, buf);
|
|
|
|
/* Queue the USB request */
|
|
ret = uvcg_video_ep_queue(video, req);
|
|
spin_unlock_irqrestore(&queue->irqlock, flags);
|
|
|
|
if (ret < 0) {
|
|
uvcg_queue_cancel(queue, 0);
|
|
break;
|
|
}
|
|
}
|
|
|
|
spin_lock_irqsave(&video->req_lock, flags);
|
|
list_add_tail(&req->list, &video->req_free);
|
|
spin_unlock_irqrestore(&video->req_lock, flags);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Enable or disable the video stream.
|
|
*/
|
|
int uvcg_video_enable(struct uvc_video *video, int enable)
|
|
{
|
|
unsigned int i;
|
|
int ret;
|
|
|
|
if (video->ep == NULL) {
|
|
uvcg_info(&video->uvc->func,
|
|
"Video enable failed, device is uninitialized.\n");
|
|
return -ENODEV;
|
|
}
|
|
|
|
if (!enable) {
|
|
for (i = 0; i < UVC_NUM_REQUESTS; ++i)
|
|
if (video->req[i])
|
|
usb_ep_dequeue(video->ep, video->req[i]);
|
|
|
|
uvc_video_free_requests(video);
|
|
uvcg_queue_enable(&video->queue, 0);
|
|
return 0;
|
|
}
|
|
|
|
if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0)
|
|
return ret;
|
|
|
|
if ((ret = uvc_video_alloc_requests(video)) < 0)
|
|
return ret;
|
|
|
|
if (video->max_payload_size) {
|
|
video->encode = uvc_video_encode_bulk;
|
|
video->payload_size = 0;
|
|
} else
|
|
video->encode = uvc_video_encode_isoc;
|
|
|
|
return uvcg_video_pump(video);
|
|
}
|
|
|
|
/*
|
|
* Initialize the UVC video stream.
|
|
*/
|
|
int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
|
|
{
|
|
INIT_LIST_HEAD(&video->req_free);
|
|
spin_lock_init(&video->req_lock);
|
|
|
|
video->uvc = uvc;
|
|
video->fcc = V4L2_PIX_FMT_YUYV;
|
|
video->bpp = 16;
|
|
video->width = 320;
|
|
video->height = 240;
|
|
video->imagesize = 320 * 240 * 2;
|
|
|
|
/* Initialize the video buffers queue. */
|
|
uvcg_queue_init(&video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT,
|
|
&video->mutex);
|
|
return 0;
|
|
}
|
|
|