/*
* uvc_video.c -- USB Video Class driver - Video handling
*
* Copyright (C) 2005-2008
* Laurent Pinchart (laurent.pinchart@skynet.be)
*
* 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/version.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/usb.h>
#include <linux/videodev2.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <asm/atomic.h>
#include <asm/unaligned.h>
#include <media/v4l2-common.h>
#include "uvcvideo.h"
/* ------------------------------------------------------------------------
* UVC Controls
*/
static int __uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
__u8 intfnum, __u8 cs, void *data, __u16 size,
int timeout)
{
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
int ret;
pipe = (query & 0x80) ? usb_rcvctrlpipe(dev->udev, 0)
: usb_sndctrlpipe(dev->udev, 0);
type |= (query & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
ret = usb_control_msg(dev->udev, pipe, query, type, cs << 8,
unit << 8 | intfnum, data, size, timeout);
if (ret != size) {
uvc_printk(KERN_ERR, "Failed to query (%u) UVC control %u "
"(unit %u) : %d (exp. %u).\n", query, cs, unit, ret,
size);
return -EIO;
}
return 0;
}
int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
__u8 intfnum, __u8 cs, void *data, __u16 size)
{
return __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size,
UVC_CTRL_CONTROL_TIMEOUT);
}
static void uvc_fixup_buffer_size(struct uvc_video_device *video,
struct uvc_streaming_control *ctrl)
{
struct uvc_format *format;
struct uvc_frame *frame;
if (ctrl->bFormatIndex <= 0 ||
ctrl->bFormatIndex > video->streaming->nformats)
return;
format = &video->streaming->format[ctrl->bFormatIndex - 1];
if (ctrl->bFrameIndex <= 0 ||
ctrl->bFrameIndex > format->nframes)
return;
frame = &format->frame[ctrl->bFrameIndex - 1];
if (!(format->flags & UVC_FMT_FLAG_COMPRESSED) ||
(ctrl->dwMaxVideoFrameSize == 0 &&
video->dev->uvc_version < 0x0110))
ctrl->dwMaxVideoFrameSize =
frame->dwMaxVideoFrameBufferSize;
}
static int uvc_get_video_ctrl(struct uvc_video_device *video,
struct uvc_streaming_control *ctrl, int probe, __u8 query)
{
__u8 *data;
__u16 size;
int ret;
size = video->dev->uvc_version >= 0x0110 ? 34 : 26;
data = kmalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
ret = __uvc_query_ctrl(video->dev, query, 0, video->streaming->intfnum,
probe ? VS_PROBE_CONTROL : VS_COMMIT_CONTROL, data, size,
UVC_CTRL_STREAMING_TIMEOUT);
if (ret < 0)
goto out;
ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
ctrl->bFormatIndex = data[2];
ctrl->bFrameIndex = data[3];
ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
ctrl->dwMaxVideoFrameSize =
le32_to_cpu(get_unaligned((__le32 *)&data[18]));
ctrl->dwMaxPayloadTransferSize =
le32_to_cpu(get_unaligned((__le32 *)&data[22]));
if (size == 34) {
ctrl->dwClockFrequency =
le32_to_cpu(get_unaligned((__le32 *)&data[26]));
ctrl->bmFramingInfo = data[30];
ctrl->bPreferedVersion = data[31];
ctrl->bMinVersion = data[32];
ctrl->bMaxVersion = data[33];
} else {
ctrl->dwClockFrequency = video->dev->clock_frequency;
ctrl->bmFramingInfo = 0;
ctrl->bPreferedVersion = 0;
ctrl->bMinVersion = 0;
ctrl->bMaxVersion = 0;
}
/* Some broken devices return a null or wrong dwMaxVideoFrameSize.
* Try to get the value from the format and frame descriptor.
*/
uvc_fixup_buffer_size(video, ctrl);
out:
kfree(data);
return ret;
}
int uvc_set_video_ctrl(struct uvc_video_device *video,
struct uvc_streaming_control *ctrl, int probe)
{
__u8 *data;
__u16 size;
int ret;
size = video->dev->uvc_version >= 0x0110 ? 34 : 26;
data = kzalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
*(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
data[2] = ctrl->bFormatIndex;
data[3] = ctrl->bFrameIndex;
*(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
*(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
*(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
*(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
*(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
*(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
/* Note: Some of the fields below are not required for IN devices (see
* UVC spec, 4.3.1.1), but we still copy them in case support for OUT
* devices is added in the future. */
put_unaligned(cpu_to_le32(ctrl->dwMaxVideoFrameSize),
(__le32 *)&data[18]);
put_unaligned(cpu_to_le32(ctrl->dwMaxPayloadTransferSize),
(__le32 *)&data[22]);
if (size == 34) {
put_unaligned(cpu_to_le32(ctrl->dwClockFrequency),
(__le32 *)&data[26]);
data[30] = ctrl->bmFramingInfo;
data[31] = ctrl->bPreferedVersion;
data[32] = ctrl->bMinVersion;
data[33] = ctrl->bMaxVersion;
}
ret = __uvc_query_ctrl(video->dev, SET_CUR, 0,
video->streaming->intfnum,
probe ? VS_PROBE_CONTROL : VS_COMMIT_CONTROL, data, size,
UVC_CTRL_STREAMING_TIMEOUT);
kfree(data);
return ret;
}
int uvc_probe_video(struct uvc_video_device *video,
struct uvc_streaming_control *probe)
{
struct uvc_streaming_control probe_min, probe_max;
__u16 bandwidth;
unsigned int i;
int ret;
mutex_lock(&video->streaming->mutex);
/* Perform probing. The device should adjust the requested values
* according to its capabilities. However, some devices, namely the
* first generation UVC Logitech webcams, don't implement the Video
* Probe control properly, and just return the needed bandwidth. For
* that reason, if the needed bandwidth exceeds the maximum available
* bandwidth, try to lower the quality.
*/
if ((ret = uvc_set_video_ctrl(video, probe, 1)) < 0)
goto done;
/* Get the minimum and maximum values for compression settings. */
if (!(video->dev->quirks & UVC_QUIRK_PROBE_MINMAX)) {
ret = uvc_get_video_ctrl(video, &probe_min, 1, GET_MIN);
if (ret < 0)
goto done;
ret = uvc_get_video_ctrl(video, &probe_max, 1, GET_MAX);
if (ret < 0)
goto done;
probe->wCompQuality = probe_max.wCompQuality;
}
for (i = 0; i < 2; ++i) {
if ((ret = uvc_set_video_ctrl(video, probe, 1)) < 0 ||
(ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0)
goto done;
if (video->streaming->intf->num_altsetting == 1)
break;
bandwidth = probe->dwMaxPayloadTransferSize;
if (bandwidth <= video->streaming->maxpsize)
break;
if (video->dev->quirks & UVC_QUIRK_PROBE_MINMAX) {
ret = -ENOSPC;
goto done;
}
/* TODO: negotiate compression parameters */
probe->wKeyFrameRate = probe_min.wKeyFrameRate;
probe->wPFrameRate = probe_min.wPFrameRate;
probe->wCompQuality = probe_max.wCompQuality;
probe->wCompWindowSize = probe_min.wCompWindowSize;
}
done:
mutex_unlock(&video->streaming->mutex);
return ret;
}
/* ------------------------------------------------------------------------
* Video codecs
*/
/* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
#define UVC_STREAM_EOH (1 << 7)
#define UVC_STREAM_ERR (1 << 6)
#define UVC_STREAM_STI (1 << 5)
#define UVC_STREAM_RES (1 << 4)
#define UVC_STREAM_SCR (1 << 3)
#define UVC_STREAM_PTS (1 << 2)
#define UVC_STREAM_EOF (1 << 1)
#define UVC_STREAM_FID (1 << 0)
/* Video payload decoding is handled by uvc_video_decode_start(),
* uvc_video_decode_data() and uvc_video_decode_end().
*
* uvc_video_decode_start is called with URB data at the start of a bulk or
* isochronous payload. It processes header data and returns the header size
* in bytes if successful. If an error occurs, it returns a negative error
* code. The following error codes have special meanings.
*
* - EAGAIN informs the caller that the current video buffer should be marked
* as done, and that the function should be called again with the same data
* and a new video buffer. This is used when end of frame conditions can be
* reliably detected at the beginning of the next frame only.
*
* If an error other than -EAGAIN is returned, the caller will drop the current
* payload. No call to uvc_video_decode_data and uvc_video_decode_end will be
* made until the next payload. -ENODATA can be used to drop the current
* payload if no other error code is appropriate.
*
* uvc_video_decode_data is called for every URB with URB data. It copies the
* data to the video buffer.
*
* uvc_video_decode_end is called with header data at the end of a bulk or
* isochronous payload. It performs any additional header data processing and
* returns 0 or a negative error code if an error occured. As header data have
* already been processed by uvc_video_decode_start, this functions isn't
* required to perform sanity checks a second time.
*
* For isochronous transfers where a payload is always transfered in a single
* URB, the three functions will be called in a row.
*
* To let the decoder process header data and update its internal state even
* when no video buffer is available, uvc_video_decode_start must be prepared
* to be called with a NULL buf parameter. uvc_video_decode_data and
* uvc_video_decode_end will never be called with a NULL buffer.
*/
static int uvc_video_decode_start(struct uvc_video_device *video,
struct uvc_buffer *buf, const __u8 *data, int len)
{
__u8 fid;
/* Sanity checks:
* - packet must be at least 2 bytes long
* - bHeaderLength value must be at least 2 bytes (see above)
* - bHeaderLength value can't be larger than the packet size.
*/
if (len < 2 || data[0] < 2 || data[0] > len)
return -EINVAL;
/* Skip payloads marked with the error bit ("error frames"). */
if (data[1] & UVC_STREAM_ERR) {
uvc_trace(UVC_TRACE_FRAME, "Dropping payload (error bit "
"set).\n");
return -ENODATA;
}
fid = data[1] & UVC_STREAM_FID;
/* Store the payload FID bit and return immediately when the buffer is
* NULL.
*/
if (buf == NULL) {
video->last_fid = fid;
return -ENODATA;
}
/* Synchronize to the input stream by waiting for the FID bit to be
* toggled when the the buffer state is not UVC_BUF_STATE_ACTIVE.
* queue->last_fid is initialized to -1, so the first isochronous
* frame will always be in sync.
*
* If the device doesn't toggle the FID bit, invert video->last_fid
* when the EOF bit is set to force synchronisation on the next packet.
*/
if (buf->state != UVC_BUF_STATE_ACTIVE) {
if (fid == video->last_fid) {
uvc_trace(UVC_TRACE_FRAME, "Dropping payload (out of "
"sync).\n");
if ((video->dev->quirks & UVC_QUIRK_STREAM_NO_FID) &&
(data[1] & UVC_STREAM_EOF))
video->last_fid ^= UVC_STREAM_FID;
return -ENODATA;
}
/* TODO: Handle PTS and SCR. */
buf->state = UVC_BUF_STATE_ACTIVE;
}
/* Mark the buffer as done if we're at the beginning of a new frame.
* End of frame detection is better implemented by checking the EOF
* bit (FID bit toggling is delayed by one frame compared to the EOF
* bit), but some devices don't set the bit at end of frame (and the
* last payload can be lost anyway). We thus must check if the FID has
* been toggled.
*
* queue->last_fid is initialized to -1, so the first isochronous
* frame will never trigger an end of frame detection.
*
* Empty buffers (bytesused == 0) don't trigger end of frame detection
* as it doesn't make sense to return an empty buffer. This also
* avoids detecting and of frame conditions at FID toggling if the
* previous payload had the EOF bit set.
*/
if (fid != video->last_fid && buf->buf.bytesused != 0) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (FID bit "
"toggled).\n");
buf->state = UVC_BUF_STATE_DONE;
return -EAGAIN;
}
video->last_fid = fid;
return data[0];
}
static void uvc_video_decode_data(struct uvc_video_device *video,
struct uvc_buffer *buf, const __u8 *data, int len)
{
struct uvc_video_queue *queue = &video->queue;
unsigned int maxlen, nbytes;
void *mem;
if (len <= 0)
return;
/* Copy the video data to the buffer. */
maxlen = buf->buf.length - buf->buf.bytesused;
mem = queue->mem + buf->buf.m.offset + buf->buf.bytesused;
nbytes = min((unsigned int)len, maxlen);
memcpy(mem, data, nbytes);
buf->buf.bytesused += nbytes;
/* Complete the current frame if the buffer size was exceeded. */
if (len > maxlen) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (overflow).\n");
buf->state = UVC_BUF_STATE_DONE;
}
}
static void uvc_video_decode_end(struct uvc_video_device *video,
struct uvc_buffer *buf, const __u8 *data, int len)
{
/* Mark the buffer as done if the EOF marker is set. */
if (data[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
uvc_trace(UVC_TRACE_FRAME, "Frame complete (EOF found).\n");
if (data[0] == len)
uvc_trace(UVC_TRACE_FRAME, "EOF in empty payload.\n");
buf->state = UVC_BUF_STATE_DONE;
if (video->dev->quirks & UVC_QUIRK_STREAM_NO_FID)
video->last_fid ^= UVC_STREAM_FID;
}
}
/* ------------------------------------------------------------------------
* URB handling
*/
/*
* Completion handler for video URBs.
*/
static void uvc_video_decode_isoc(struct urb *urb,
struct uvc_video_device *video, struct uvc_buffer *buf)
{
u8 *mem;
int ret, i;
for (i = 0; i < urb->number_of_packets; ++i) {
if (urb->iso_frame_desc[i].status < 0) {
uvc_trace(UVC_TRACE_FRAME, "USB isochronous frame "
"lost (%d).\n", urb->iso_frame_desc[i].status);
continue;
}
/* Decode the payload header. */
mem = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
do {
ret = uvc_video_decode_start(video, buf, mem,
urb->iso_frame_desc[i].actual_length);
if (ret == -EAGAIN)
buf = uvc_queue_next_buffer(&video->queue, buf);
} while (ret == -EAGAIN);
if (ret < 0)
continue;
/* Decode the payload data. */
uvc_video_decode_data(video, buf, mem + ret,
urb->iso_frame_desc[i].actual_length - ret);
/* Process the header again. */
uvc_video_decode_end(video, buf, mem, ret);
if (buf->state == UVC_BUF_STATE_DONE ||
buf->state == UVC_BUF_STATE_ERROR)
buf = uvc_queue_next_buffer(&video->queue, buf);
}
}
static void uvc_video_decode_bulk(struct urb *urb,
struct uvc_video_device *video, struct uvc_buffer *buf)
{
u8 *mem;
int len, ret;
mem = urb->transfer_buffer;
len = urb->actual_length;
video->bulk.payload_size += len;
/* If the URB is the first of its payload, decode and save the
* header.
*/
if (video->bulk.header_size == 0) {
do {
ret = uvc_video_decode_start(video, buf, mem, len);
if (ret == -EAGAIN)
buf = uvc_queue_next_buffer(&video->queue, buf);
} while (ret == -EAGAIN);
/* If an error occured skip the rest of the payload. */
if (ret < 0 || buf == NULL) {
video->bulk.skip_payload = 1;
return;
}
video->bulk.header_size = ret;
memcpy(video->bulk.header, mem, video->bulk.header_size);
mem += ret;
len -= ret;
}
/* The buffer queue might have been cancelled while a bulk transfer
* was in progress, so we can reach here with buf equal to NULL. Make
* sure buf is never dereferenced if NULL.
*/
/* Process video data. */
if (!video->bulk.skip_payload && buf != NULL)
uvc_video_decode_data(video, buf, mem, len);
/* Detect the payload end by a URB smaller than the maximum size (or
* a payload size equal to the maximum) and process the header again.
*/
if (urb->actual_length < urb->transfer_buffer_length ||
video->bulk.payload_size >= video->bulk.max_payload_size) {
if (!video->bulk.skip_payload && buf != NULL) {
uvc_video_decode_end(video, buf, video->bulk.header,
video->bulk.header_size);
if (buf->state == UVC_BUF_STATE_DONE ||
buf->state == UVC_BUF_STATE_ERROR)
buf = uvc_queue_next_buffer(&video->queue, buf);
}
video->bulk.header_size = 0;
video->bulk.skip_payload = 0;
video->bulk.payload_size = 0;
}
}
static void uvc_video_complete(struct urb *urb)
{
struct uvc_video_device *video = urb->context;
struct uvc_video_queue *queue = &video->queue;
struct uvc_buffer *buf = NULL;
unsigned long flags;
int ret;
switch (urb->status) {
case 0:
break;
default:
uvc_printk(KERN_WARNING, "Non-zero status (%d) in video "
"completion handler.\n", urb->status);
case -ENOENT: /* usb_kill_urb() called. */
if (video->frozen)
return;
case -ECONNRESET: /* usb_unlink_urb() called. */
case -ESHUTDOWN: /* The endpoint is being disabled. */
uvc_queue_cancel(queue, urb->status == -ESHUTDOWN);
return;
}
spin_lock_irqsave(&queue->irqlock, flags);
if (!list_empty(&queue->irqqueue))
buf = list_first_entry(&queue->irqqueue, struct uvc_buffer,
queue);
spin_unlock_irqrestore(&queue->irqlock, flags);
video->decode(urb, video, buf);
if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
uvc_printk(KERN_ERR, "Failed to resubmit video URB (%d).\n",
ret);
}
}
/*
* Free transfer buffers.
*/
static void uvc_free_urb_buffers(struct uvc_video_device *video)
{
unsigned int i;
for (i = 0; i < UVC_URBS; ++i) {
if (video->urb_buffer[i]) {
usb_buffer_free(video->dev->udev, video->urb_size,
video->urb_buffer[i], video->urb_dma[i]);
video->urb_buffer[i] = NULL;
}
}
video->urb_size = 0;
}
/*
* Allocate transfer buffers. This function can be called with buffers
* already allocated when resuming from suspend, in which case it will
* return without touching the buffers.
*
* Return 0 on success or -ENOMEM when out of memory.
*/
static int uvc_alloc_urb_buffers(struct uvc_video_device *video,
unsigned int size)
{
unsigned int i;
/* Buffers are already allocated, bail out. */
if (video->urb_size)
return 0;
for (i = 0; i < UVC_URBS; ++i) {
video->urb_buffer[i] = usb_buffer_alloc(video->dev->udev,
size, GFP_KERNEL, &video->urb_dma[i]);
if (video->urb_buffer[i] == NULL) {
uvc_free_urb_buffers(video);
return -ENOMEM;
}
}
video->urb_size = size;
return 0;
}
/*
* Uninitialize isochronous/bulk URBs and free transfer buffers.
*/
static void uvc_uninit_video(struct uvc_video_device *video, int free_buffers)
{
struct urb *urb;
unsigned int i;
for (i = 0; i < UVC_URBS; ++i) {
if ((urb = video->urb[i]) == NULL)
continue;
usb_kill_urb(urb);
usb_free_urb(urb);
video->urb[i] = NULL;
}
if (free_buffers)
uvc_free_urb_buffers(video);
}
/*
* Initialize isochronous URBs and allocate transfer buffers. The packet size
* is given by the endpoint.
*/
static int uvc_init_video_isoc(struct uvc_video_device *video,
struct usb_host_endpoint *ep, gfp_t gfp_flags)
{
struct urb *urb;
unsigned int npackets, i, j;
__u16 psize;
__u32 size;
/* Compute the number of isochronous packets to allocate by dividing
* the maximum video frame size by the packet size. Limit the result
* to UVC_MAX_ISO_PACKETS.
*/
psize = le16_to_cpu(ep->desc.wMaxPacketSize);
psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
size = video->streaming->ctrl.dwMaxVideoFrameSize;
if (size > UVC_MAX_FRAME_SIZE)
return -EINVAL;
npackets = (size + psize - 1) / psize;
if (npackets > UVC_MAX_ISO_PACKETS)
npackets = UVC_MAX_ISO_PACKETS;
size = npackets * psize;
if (uvc_alloc_urb_buffers(video, size) < 0)
return -ENOMEM;
for (i = 0; i < UVC_URBS; ++i) {
urb = usb_alloc_urb(npackets, gfp_flags);
if (urb == NULL) {
uvc_uninit_video(video, 1);
return -ENOMEM;
}
urb->dev = video->dev->udev;
urb->context = video;
urb->pipe = usb_rcvisocpipe(video->dev->udev,
ep->desc.bEndpointAddress);
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
urb->interval = ep->desc.bInterval;
urb->transfer_buffer = video->urb_buffer[i];
urb->transfer_dma = video->urb_dma[i];
urb->complete = uvc_video_complete;
urb->number_of_packets = npackets;
urb->transfer_buffer_length = size;
for (j = 0; j < npackets; ++j) {
urb->iso_frame_desc[j].offset = j * psize;
urb->iso_frame_desc[j].length = psize;
}
video->urb[i] = urb;
}
return 0;
}
/*
* Initialize bulk URBs and allocate transfer buffers. The packet size is
* given by the endpoint.
*/
static int uvc_init_video_bulk(struct uvc_video_device *video,
struct usb_host_endpoint *ep, gfp_t gfp_flags)
{
struct urb *urb;
unsigned int pipe, i;
__u16 psize;
__u32 size;
/* Compute the bulk URB size. Some devices set the maximum payload
* size to a value too high for memory-constrained devices. We must
* then transfer the payload accross multiple URBs. To be consistant
* with isochronous mode, allocate maximum UVC_MAX_ISO_PACKETS per bulk
* URB.
*/
psize = le16_to_cpu(ep->desc.wMaxPacketSize) & 0x07ff;
size = video->streaming->ctrl.dwMaxPayloadTransferSize;
video->bulk.max_payload_size = size;
if (size > psize * UVC_MAX_ISO_PACKETS)
size = psize * UVC_MAX_ISO_PACKETS;
if (uvc_alloc_urb_buffers(video, size) < 0)
return -ENOMEM;
pipe = usb_rcvbulkpipe(video->dev->udev, ep->desc.bEndpointAddress);
for (i = 0; i < UVC_URBS; ++i) {
urb = usb_alloc_urb(0, gfp_flags);
if (urb == NULL) {
uvc_uninit_video(video, 1);
return -ENOMEM;
}
usb_fill_bulk_urb(urb, video->dev->udev, pipe,
video->urb_buffer[i], size, uvc_video_complete,
video);
urb->transfer_flags = URB_NO_TRANSFER_DMA_MAP;
urb->transfer_dma = video->urb_dma[i];
video->urb[i] = urb;
}
return 0;
}
/*
* Initialize isochronous/bulk URBs and allocate transfer buffers.
*/
static int uvc_init_video(struct uvc_video_device *video, gfp_t gfp_flags)
{
struct usb_interface *intf = video->streaming->intf;
struct usb_host_interface *alts;
struct usb_host_endpoint *ep = NULL;
int intfnum = video->streaming->intfnum;
unsigned int bandwidth, psize, i;
int ret;
video->last_fid = -1;
video->bulk.header_size = 0;
video->bulk.skip_payload = 0;
video->bulk.payload_size = 0;
if (intf->num_altsetting > 1) {
/* Isochronous endpoint, select the alternate setting. */
bandwidth = video->streaming->ctrl.dwMaxPayloadTransferSize;
if (bandwidth == 0) {
uvc_printk(KERN_WARNING, "device %s requested null "
"bandwidth, defaulting to lowest.\n",
video->vdev->name);
bandwidth = 1;
}
for (i = 0; i < intf->num_altsetting; ++i) {
alts = &intf->altsetting[i];
ep = uvc_find_endpoint(alts,
video->streaming->header.bEndpointAddress);
if (ep == NULL)
continue;
/* Check if the bandwidth is high enough. */
psize = le16_to_cpu(ep->desc.wMaxPacketSize);
psize = (psize & 0x07ff) * (1 + ((psize >> 11) & 3));
if (psize >= bandwidth)
break;
}
if (i >= intf->num_altsetting)
return -EIO;
if ((ret = usb_set_interface(video->dev->udev, intfnum, i)) < 0)
return ret;
ret = uvc_init_video_isoc(video, ep, gfp_flags);
} else {
/* Bulk endpoint, proceed to URB initialization. */
ep = uvc_find_endpoint(&intf->altsetting[0],
video->streaming->header.bEndpointAddress);
if (ep == NULL)
return -EIO;
ret = uvc_init_video_bulk(video, ep, gfp_flags);
}
if (ret < 0)
return ret;
/* Submit the URBs. */
for (i = 0; i < UVC_URBS; ++i) {
if ((ret = usb_submit_urb(video->urb[i], gfp_flags)) < 0) {
uvc_printk(KERN_ERR, "Failed to submit URB %u "
"(%d).\n", i, ret);
uvc_uninit_video(video, 1);
return ret;
}
}
return 0;
}
/* --------------------------------------------------------------------------
* Suspend/resume
*/
/*
* Stop streaming without disabling the video queue.
*
* To let userspace applications resume without trouble, we must not touch the
* video buffers in any way. We mark the device as frozen to make sure the URB
* completion handler won't try to cancel the queue when we kill the URBs.
*/
int uvc_video_suspend(struct uvc_video_device *video)
{
if (!uvc_queue_streaming(&video->queue))
return 0;
video->frozen = 1;
uvc_uninit_video(video, 0);
usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
return 0;
}
/*
* Reconfigure the video interface and restart streaming if it was enable
* before suspend.
*
* If an error occurs, disable the video queue. This will wake all pending
* buffers, making sure userspace applications are notified of the problem
* instead of waiting forever.
*/
int uvc_video_resume(struct uvc_video_device *video)
{
int ret;
video->frozen = 0;
if ((ret = uvc_set_video_ctrl(video, &video->streaming->ctrl, 0)) < 0) {
uvc_queue_enable(&video->queue, 0);
return ret;
}
if (!uvc_queue_streaming(&video->queue))
return 0;
if ((ret = uvc_init_video(video, GFP_NOIO)) < 0)
uvc_queue_enable(&video->queue, 0);
return ret;
}
/* ------------------------------------------------------------------------
* Video device
*/
/*
* Initialize the UVC video device by retrieving the default format and
* committing it.
*
* Some cameras (namely the Fuji Finepix) set the format and frame
* indexes to zero. The UVC standard doesn't clearly make this a spec
* violation, so try to silently fix the values if possible.
*
* This function is called before registering the device with V4L.
*/
int uvc_video_init(struct uvc_video_device *video)
{
struct uvc_streaming_control *probe = &video->streaming->ctrl;
struct uvc_format *format = NULL;
struct uvc_frame *frame = NULL;
unsigned int i;
int ret;
if (video->streaming->nformats == 0) {
uvc_printk(KERN_INFO, "No supported video formats found.\n");
return -EINVAL;
}
/* Alternate setting 0 should be the default, yet the XBox Live Vision
* Cam (and possibly other devices) crash or otherwise misbehave if
* they don't receive a SET_INTERFACE request before any other video
* control request.
*/
usb_set_interface(video->dev->udev, video->streaming->intfnum, 0);
/* Some webcams don't suport GET_DEF request on the probe control. We
* fall back to GET_CUR if GET_DEF fails.
*/
if ((ret = uvc_get_video_ctrl(video, probe, 1, GET_DEF)) < 0 &&
(ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR)) < 0)
return ret;
/* Check if the default format descriptor exists. Use the first
* available format otherwise.
*/
for (i = video->streaming->nformats; i > 0; --i) {
format = &video->streaming->format[i-1];
if (format->index == probe->bFormatIndex)
break;
}
if (format->nframes == 0) {
uvc_printk(KERN_INFO, "No frame descriptor found for the "
"default format.\n");
return -EINVAL;
}
/* Zero bFrameIndex might be correct. Stream-based formats (including
* MPEG-2 TS and DV) do not support frames but have a dummy frame
* descriptor with bFrameIndex set to zero. If the default frame
* descriptor is not found, use the first avalable frame.
*/
for (i = format->nframes; i > 0; --i) {
frame = &format->frame[i-1];
if (frame->bFrameIndex == probe->bFrameIndex)
break;
}
/* Commit the default settings. */
probe->bFormatIndex = format->index;
probe->bFrameIndex = frame->bFrameIndex;
if ((ret = uvc_set_video_ctrl(video, probe, 0)) < 0)
return ret;
video->streaming->cur_format = format;
video->streaming->cur_frame = frame;
atomic_set(&video->active, 0);
/* Select the video decoding function */
if (video->dev->quirks & UVC_QUIRK_BUILTIN_ISIGHT)
video->decode = uvc_video_decode_isight;
else if (video->streaming->intf->num_altsetting > 1)
video->decode = uvc_video_decode_isoc;
else
video->decode = uvc_video_decode_bulk;
return 0;
}
/*
* Enable or disable the video stream.
*/
int uvc_video_enable(struct uvc_video_device *video, int enable)
{
int ret;
if (!enable) {
uvc_uninit_video(video, 1);
usb_set_interface(video->dev->udev,
video->streaming->intfnum, 0);
uvc_queue_enable(&video->queue, 0);
return 0;
}
if ((ret = uvc_queue_enable(&video->queue, 1)) < 0)
return ret;
return uvc_init_video(video, GFP_KERNEL);
}
