mirror of https://gitee.com/openkylin/linux.git
387 lines
9.4 KiB
C
387 lines
9.4 KiB
C
|
/*
|
||
|
* uvc_video.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/usb/ch9.h>
|
||
|
#include <linux/usb/gadget.h>
|
||
|
|
||
|
#include <media/v4l2-dev.h>
|
||
|
|
||
|
#include "uvc.h"
|
||
|
#include "uvc_queue.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->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 = queue->mem + buf->buf.m.offset + queue->buf_used;
|
||
|
nbytes = min((unsigned int)len, buf->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->buf.bytesused == video->queue.buf_used) {
|
||
|
video->queue.buf_used = 0;
|
||
|
buf->state = UVC_BUF_STATE_DONE;
|
||
|
uvc_queue_next_buffer(&video->queue, buf);
|
||
|
video->fid ^= UVC_STREAM_FID;
|
||
|
|
||
|
video->payload_size = 0;
|
||
|
}
|
||
|
|
||
|
if (video->payload_size == video->max_payload_size ||
|
||
|
buf->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->buf.bytesused == video->queue.buf_used) {
|
||
|
video->queue.buf_used = 0;
|
||
|
buf->state = UVC_BUF_STATE_DONE;
|
||
|
uvc_queue_next_buffer(&video->queue, buf);
|
||
|
video->fid ^= UVC_STREAM_FID;
|
||
|
}
|
||
|
}
|
||
|
|
||
|
/* --------------------------------------------------------------------------
|
||
|
* Request handling
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* 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_buffer *buf;
|
||
|
unsigned long flags;
|
||
|
int ret;
|
||
|
|
||
|
switch (req->status) {
|
||
|
case 0:
|
||
|
break;
|
||
|
|
||
|
case -ESHUTDOWN:
|
||
|
printk(KERN_INFO "VS request cancelled.\n");
|
||
|
goto requeue;
|
||
|
|
||
|
default:
|
||
|
printk(KERN_INFO "VS request completed with status %d.\n",
|
||
|
req->status);
|
||
|
goto requeue;
|
||
|
}
|
||
|
|
||
|
spin_lock_irqsave(&video->queue.irqlock, flags);
|
||
|
buf = uvc_queue_head(&video->queue);
|
||
|
if (buf == NULL) {
|
||
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
||
|
goto requeue;
|
||
|
}
|
||
|
|
||
|
video->encode(req, video, buf);
|
||
|
|
||
|
if ((ret = usb_ep_queue(ep, req, GFP_ATOMIC)) < 0) {
|
||
|
printk(KERN_INFO "Failed to queue request (%d).\n", ret);
|
||
|
usb_ep_set_halt(ep);
|
||
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
||
|
goto requeue;
|
||
|
}
|
||
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
||
|
|
||
|
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 i;
|
||
|
int ret = -ENOMEM;
|
||
|
|
||
|
BUG_ON(video->req_size);
|
||
|
|
||
|
for (i = 0; i < UVC_NUM_REQUESTS; ++i) {
|
||
|
video->req_buffer[i] = kmalloc(video->ep->maxpacket, 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]->dma = DMA_ADDR_INVALID;
|
||
|
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 = video->ep->maxpacket;
|
||
|
return 0;
|
||
|
|
||
|
error:
|
||
|
uvc_video_free_requests(video);
|
||
|
return ret;
|
||
|
}
|
||
|
|
||
|
/* --------------------------------------------------------------------------
|
||
|
* Video streaming
|
||
|
*/
|
||
|
|
||
|
/*
|
||
|
* uvc_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
|
||
|
uvc_video_pump(struct uvc_video *video)
|
||
|
{
|
||
|
struct usb_request *req;
|
||
|
struct uvc_buffer *buf;
|
||
|
unsigned long flags;
|
||
|
int ret;
|
||
|
|
||
|
/* FIXME TODO Race between uvc_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(&video->queue.irqlock, flags);
|
||
|
buf = uvc_queue_head(&video->queue);
|
||
|
if (buf == NULL) {
|
||
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
||
|
break;
|
||
|
}
|
||
|
|
||
|
video->encode(req, video, buf);
|
||
|
|
||
|
/* Queue the USB request */
|
||
|
if ((ret = usb_ep_queue(video->ep, req, GFP_KERNEL)) < 0) {
|
||
|
printk(KERN_INFO "Failed to queue request (%d)\n", ret);
|
||
|
usb_ep_set_halt(video->ep);
|
||
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
||
|
break;
|
||
|
}
|
||
|
spin_unlock_irqrestore(&video->queue.irqlock, flags);
|
||
|
}
|
||
|
|
||
|
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
|
||
|
uvc_video_enable(struct uvc_video *video, int enable)
|
||
|
{
|
||
|
unsigned int i;
|
||
|
int ret;
|
||
|
|
||
|
if (video->ep == NULL) {
|
||
|
printk(KERN_INFO "Video enable failed, device is "
|
||
|
"uninitialized.\n");
|
||
|
return -ENODEV;
|
||
|
}
|
||
|
|
||
|
if (!enable) {
|
||
|
for (i = 0; i < UVC_NUM_REQUESTS; ++i)
|
||
|
usb_ep_dequeue(video->ep, video->req[i]);
|
||
|
|
||
|
uvc_video_free_requests(video);
|
||
|
uvc_queue_enable(&video->queue, 0);
|
||
|
return 0;
|
||
|
}
|
||
|
|
||
|
if ((ret = uvc_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 uvc_video_pump(video);
|
||
|
}
|
||
|
|
||
|
/*
|
||
|
* Initialize the UVC video stream.
|
||
|
*/
|
||
|
int
|
||
|
uvc_video_init(struct uvc_video *video)
|
||
|
{
|
||
|
INIT_LIST_HEAD(&video->req_free);
|
||
|
spin_lock_init(&video->req_lock);
|
||
|
|
||
|
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. */
|
||
|
uvc_queue_init(&video->queue, V4L2_BUF_TYPE_VIDEO_OUTPUT);
|
||
|
return 0;
|
||
|
}
|
||
|
|