V4L2摄像头驱动移植
摄像头驱动源代码路径：/drivers/media/video/uvc/uvc_v4l2.c
配置摄像v4l2驱动
make menuconfigDevice Drivers --->
<*> Multimedia support --->
<*> Video For Linux
[*] Video capture adapters --->
[*] V4L USB devices --->
<*> USB Video Class (UVC)
一般都符合UVC规范，不用修改源码，除非是自己定制的摄像头驱动，自己购买cmos摄像头，然后加上dsp处理图片，压缩成MJPEG格式，为了让视频更加流畅，这也只需要修改很小部分的代码。
自己写V4L2驱动：myuvc.c
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include
#include "uvcvideo.h"
/* 参考 drivers/media/video/uvc */
#define MYUVC_URBS 5
/* 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)
struct myuvc_streaming_control {
__u16 bmHint;
__u8 bFormatIndex;
__u8 bFrameIndex;
__u32 dwFrameInterval;
__u16 wKeyFrameRate;
__u16 wPFrameRate;
__u16 wCompQuality;
__u16 wCompWindowSize;
__u16 wDelay;
__u32 dwMaxVideoFrameSize;
__u32 dwMaxPayloadTransferSize;
__u32 dwClockFrequency;
__u8 bmFramingInfo;
__u8 bPreferedVersion;
__u8 bMinVersion;
__u8 bMaxVersion;
};
struct frame_desc {
int width;
int height;
};
/* 参考uvc_video_queue定义一些结构体 */
struct myuvc_buffer {
struct v4l2_buffer buf;
int state;
int vma_use_count; /* 表示是否已经被mmap */
wait_queue_head_t wait; /* APP要读某个缓冲区,如果无数据,在此休眠 */
struct list_head stream;
struct list_head irq;
};
struct myuvc_queue {
void *mem;
int count;
int buf_size;
struct myuvc_buffer buffer[32];
struct urb *urb[32];
char *urb_buffer[32];
dma_addr_t urb_dma[32];
unsigned int urb_size;
struct list_head mainqueue; /* 供APP消费用 */
struct list_head irqqueue; /* 供底层驱动生产用 */
};
static struct myuvc_queue myuvc_queue;
static struct video_device *myuvc_vdev;
static struct usb_device *myuvc_udev;
static int myuvc_bEndpointAddress = 0x81;
static int myuvc_streaming_intf;
static int myuvc_control_intf;
static int myuvc_streaming_bAlternateSetting = 8;
static struct v4l2_format myuvc_format;
static struct frame_desc frames[] = {{640, 480}, {352, 288}, {320, 240}, {176, 144}, {160, 120}};
static int frame_idx = 1;
static int bBitsPerPixel = 16; /* lsusb -v -d 0x1e4e: "bBitsPerPixel" */
static int uvc_version = 0x0100; /* lsusb -v -d 0x1e4e: bcdUVC */
static int wMaxPacketSize = 1024;
static int ProcessingUnitID = 3;
static struct myuvc_streaming_control myuvc_params;
/* A2 参考 uvc_v4l2_do_ioctl */
static int myuvc_vidioc_querycap(struct file *file, void *priv,
struct v4l2_capability *cap)
{
memset(cap, 0, sizeof *cap);
strcpy(cap->driver, "myuvc");
strcpy(cap->card, "myuvc");
cap->version = 1;
cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
return 0;
}
/* A3 列举支持哪种格式
* 参考: uvc_fmts 数组
*/
static int myuvc_vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
struct v4l2_fmtdesc *f)
{
/* 人工查看描述符可知我们用的摄像头只支持1种格式 */
if (f->index >= 1)
return -EINVAL;
/* 支持什么格式呢?
* 查看VideoStreaming Interface的描述符,
* 得到GUID为"59 55 59 32 00 00 10 00 80 00 00 aa 00 38 9b 71"
*/
strcpy(f->description, "4:2:2, packed, YUYV");
f->pixelformat = V4L2_PIX_FMT_YUYV;
return 0;
}
/* A4 返回当前所使用的格式 */
static int myuvc_vidioc_g_fmt_vid_cap(struct file *file, void *priv,
struct v4l2_format *f)
{
memcpy(f, &myuvc_format, sizeof(myuvc_format));
return (0);
}
/* A5 测试驱动程序是否支持某种格式, 强制设置该格式
* 参考: uvc_v4l2_try_format
* myvivi_vidioc_try_fmt_vid_cap
*/
static int myuvc_vidioc_try_fmt_vid_cap(struct file *file, void *priv,
struct v4l2_format *f)
{
if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
{
return -EINVAL;
}
if (f->fmt.pix.pixelformat != V4L2_PIX_FMT_YUYV)
return -EINVAL;
/* 调整format的width, height,
* 计算bytesperline, sizeimage
*/
/* 人工查看描述符, 确定支持哪几种分辨率 */
f->fmt.pix.width = frames[frame_idx].width;
f->fmt.pix.height = frames[frame_idx].height;
f->fmt.pix.bytesperline =
(f->fmt.pix.width * bBitsPerPixel) >> 3;
f->fmt.pix.sizeimage =
f->fmt.pix.height * f->fmt.pix.bytesperline;
return 0;
}
/* A6 参考 myvivi_vidioc_s_fmt_vid_cap */
static int myuvc_vidioc_s_fmt_vid_cap(struct file *file, void *priv,
struct v4l2_format *f)
{
int ret = myuvc_vidioc_try_fmt_vid_cap(file, NULL, f);
if (ret < 0)
return ret;
memcpy(&myuvc_format, f, sizeof(myuvc_format));
return 0;
}
static int myuvc_free_buffers(void)
{
if (myuvc_queue.mem)
{
vfree(myuvc_queue.mem);
memset(&myuvc_queue, 0, sizeof(myuvc_queue));
myuvc_queue.mem = NULL;
}
return 0;
}
/* A7 APP调用该ioctl让驱动程序分配若干个缓存, APP将从这些缓存中读到视频数据
* 参考: uvc_alloc_buffers
*/
static int myuvc_vidioc_reqbufs(struct file *file, void *priv,
struct v4l2_requestbuffers *p)
{
int nbuffers = p->count;
int bufsize = PAGE_ALIGN(myuvc_format.fmt.pix.sizeimage);
unsigned int i;
void *mem = NULL;
int ret;
if ((ret = myuvc_free_buffers()) < 0)
goto done;
/* Bail out if no buffers should be allocated. */
if (nbuffers == 0)
goto done;
/* Decrement the number of buffers until allocation succeeds. */
for (; nbuffers > 0; --nbuffers) {
mem = vmalloc_32(nbuffers * bufsize);
if (mem != NULL)
break;
}
if (mem == NULL) {
ret = -ENOMEM;
goto done;
}
/* 这些缓存是一次性作为一个整体来分配的 */
memset(&myuvc_queue, 0, sizeof(myuvc_queue));
INIT_LIST_HEAD(&myuvc_queue.mainqueue);
INIT_LIST_HEAD(&myuvc_queue.irqqueue);
for (i = 0; i < nbuffers; ++i) {
myuvc_queue.buffer[i].buf.index = i;
myuvc_queue.buffer[i].buf.m.offset = i * bufsize;
myuvc_queue.buffer[i].buf.length = myuvc_format.fmt.pix.sizeimage;
myuvc_queue.buffer[i].buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
myuvc_queue.buffer[i].buf.sequence = 0;
myuvc_queue.buffer[i].buf.field = V4L2_FIELD_NONE;
myuvc_queue.buffer[i].buf.memory = V4L2_MEMORY_MMAP;
myuvc_queue.buffer[i].buf.flags = 0;
myuvc_queue.buffer[i].state = VIDEOBUF_IDLE;
init_waitqueue_head(&myuvc_queue.buffer[i].wait);
}
myuvc_queue.mem = mem;
myuvc_queue.count = nbuffers;
myuvc_queue.buf_size = bufsize;
ret = nbuffers;
done:
return ret;
}
/* A8 查询缓存状态, 比如地址信息(APP可以用mmap进行映射)
* 参考 uvc_query_buffer
*/
static int myuvc_vidioc_querybuf(struct file *file, void *priv, struct v4l2_buffer *v4l2_buf)
{
int ret = 0;
if (v4l2_buf->index >= myuvc_queue.count) {
ret = -EINVAL;
goto done;
}
memcpy(v4l2_buf, &myuvc_queue.buffer[v4l2_buf->index].buf, sizeof(*v4l2_buf));
/* 更新flags */
if (myuvc_queue.buffer[v4l2_buf->index].vma_use_count)
v4l2_buf->flags |= V4L2_BUF_FLAG_MAPPED;
switch (myuvc_queue.buffer[v4l2_buf->index].state) {
case VIDEOBUF_ERROR:
case VIDEOBUF_DONE:
v4l2_buf->flags |= V4L2_BUF_FLAG_DONE;
break;
case VIDEOBUF_QUEUED:
case VIDEOBUF_ACTIVE:
v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
break;
case VIDEOBUF_IDLE:
default:
break;
}
done:
return ret;
}
/* A10 把缓冲区放入队列, 底层的硬件操作函数将会把数据放入这个队列的缓存
* 参考: uvc_queue_buffer
*/
static int myuvc_vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *v4l2_buf)
{
struct myuvc_buffer *buf;
/* 0. APP传入的v4l2_buf可能有问题, 要做判断 */
if (v4l2_buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
v4l2_buf->memory != V4L2_MEMORY_MMAP) {
return -EINVAL;
}
if (v4l2_buf->index >= myuvc_queue.count) {
return -EINVAL;
}
buf = &myuvc_queue.buffer[v4l2_buf->index];
if (buf->state != VIDEOBUF_IDLE) {
return -EINVAL;
}
/* 1. 修改状态 */
buf->state = VIDEOBUF_QUEUED;
buf->buf.bytesused = 0;
/* 2. 放入2个队列 */
/* 队列1: 供APP使用
* 当缓冲区没有数据时,放入mainqueue队列
* 当缓冲区有数据时, APP从mainqueue队列中取出
*/
list_add_tail(&buf->stream, &myuvc_queue.mainqueue);
/* 队列2: 供产生数据的函数使用
* 当采集到数据时,从irqqueue队列中取出第1个缓冲区,存入数据
*/
list_add_tail(&buf->irq, &myuvc_queue.irqqueue);
return 0;
}
static void myuvc_print_streaming_params(struct myuvc_streaming_control *ctrl)
{
printk("video params:\n");
printk("bmHint = %d\n", ctrl->bmHint);
printk("bFormatIndex = %d\n", ctrl->bFormatIndex);
printk("bFrameIndex = %d\n", ctrl->bFrameIndex);
printk("dwFrameInterval = %d\n", ctrl->dwFrameInterval);
printk("wKeyFrameRate = %d\n", ctrl->wKeyFrameRate);
printk("wPFrameRate = %d\n", ctrl->wPFrameRate);
printk("wCompQuality = %d\n", ctrl->wCompQuality);
printk("wCompWindowSize = %d\n", ctrl->wCompWindowSize);
printk("wDelay = %d\n", ctrl->wDelay);
printk("dwMaxVideoFrameSize = %d\n", ctrl->dwMaxVideoFrameSize);
printk("dwMaxPayloadTransferSize = %d\n", ctrl->dwMaxPayloadTransferSize);
printk("dwClockFrequency = %d\n", ctrl->dwClockFrequency);
printk("bmFramingInfo = %d\n", ctrl->bmFramingInfo);
printk("bPreferedVersion = %d\n", ctrl->bPreferedVersion);
printk("bMinVersion = %d\n", ctrl->bMinVersion);
printk("bMinVersion = %d\n", ctrl->bMinVersion);
}
/* 参考: uvc_get_video_ctrl
(ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR))
static int uvc_get_video_ctrl(struct uvc_video_device *video,
struct uvc_streaming_control *ctrl, int probe, __u8 query)
*/
static int myuvc_get_streaming_params(struct myuvc_streaming_control *ctrl)
{
__u8 *data;
__u16 size;
int ret;
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
size = uvc_version >= 0x0110 ? 34 : 26;
data = kmalloc(size, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
pipe = (GET_CUR & 0x80) ? usb_rcvctrlpipe(myuvc_udev, 0)
: usb_sndctrlpipe(myuvc_udev, 0);
type |= (GET_CUR & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
ret = usb_control_msg(myuvc_udev, pipe, GET_CUR, type, VS_PROBE_CONTROL << 8,
0 << 8 | myuvc_streaming_intf, data, size, 5000);
if (ret < 0)
goto done;
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 = get_unaligned_le32(&data[18]);
ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
if (size == 34) {
ctrl->dwClockFrequency = 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;
}
done:
kfree(data);
return (ret < 0) ? ret : 0;
}
/* 参考: uvc_v4l2_try_format ∕uvc_probe_video
* uvc_set_video_ctrl(video, probe, 1)
*/
static int myuvc_try_streaming_params(struct myuvc_streaming_control *ctrl)
{
__u8 *data;
__u16 size;
int ret;
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
memset(ctrl, 0, sizeof *ctrl);
ctrl->bmHint = 1; /* dwFrameInterval */
ctrl->bFormatIndex = 1;
ctrl->bFrameIndex = frame_idx + 1;
ctrl->dwFrameInterval = 333333;
size = 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);
put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
if (size == 34) {
put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
data[30] = ctrl->bmFramingInfo;
data[31] = ctrl->bPreferedVersion;
data[32] = ctrl->bMinVersion;
data[33] = ctrl->bMaxVersion;
}
pipe = (SET_CUR & 0x80) ? usb_rcvctrlpipe(myuvc_udev, 0)
: usb_sndctrlpipe(myuvc_udev, 0);
type |= (SET_CUR & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
ret = usb_control_msg(myuvc_udev, pipe, SET_CUR, type, VS_PROBE_CONTROL << 8,
0 << 8 | myuvc_streaming_intf, data, size, 5000);
kfree(data);
return (ret < 0) ? ret : 0;
}
/* 参考: uvc_v4l2_try_format ∕uvc_probe_video
* uvc_set_video_ctrl(video, probe, 1)
*/
static int myuvc_set_streaming_params(struct myuvc_streaming_control *ctrl)
{
__u8 *data;
__u16 size;
int ret;
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
size = 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);
put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
if (size == 34) {
put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
data[30] = ctrl->bmFramingInfo;
data[31] = ctrl->bPreferedVersion;
data[32] = ctrl->bMinVersion;
data[33] = ctrl->bMaxVersion;
}
pipe = (SET_CUR & 0x80) ? usb_rcvctrlpipe(myuvc_udev, 0)
: usb_sndctrlpipe(myuvc_udev, 0);
type |= (SET_CUR & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
ret = usb_control_msg(myuvc_udev, pipe, SET_CUR, type, VS_COMMIT_CONTROL << 8,
0 << 8 | myuvc_streaming_intf, data, size, 5000);
kfree(data);
return (ret < 0) ? ret : 0;
}
static void myuvc_uninit_urbs(void)
{
int i;
for (i = 0; i < MYUVC_URBS; ++i) {
if (myuvc_queue.urb_buffer[i])
{
usb_buffer_free(myuvc_udev, myuvc_queue.urb_size, myuvc_queue.urb_buffer[i], myuvc_queue.urb_dma[i]);
myuvc_queue.urb_buffer[i] = NULL;
}
if (myuvc_queue.urb[i])
{
usb_free_urb(myuvc_queue.urb[i]);
myuvc_queue.urb[i] = NULL;
}
}
}
/* 参考: uvc_video_complete / uvc_video_decode_isoc */
static void myuvc_video_complete(struct urb *urb)
{
u8 *src;
u8 *dest;
int ret, i;
int len;
int maxlen;
int nbytes;
struct myuvc_buffer *buf;
switch (urb->status) {
case 0:
break;
default:
printk("Non-zero status (%d) in video "
"completion handler.\n", urb->status);
return;
}
/* 从irqqueue队列中取出第1个缓冲区 */
if (!list_empty(&myuvc_queue.irqqueue))
{
buf = list_first_entry(&myuvc_queue.irqqueue, struct myuvc_buffer, irq);
for (i = 0; i < urb->number_of_packets; ++i) {
if (urb->iso_frame_desc[i].status < 0) {
printk("USB isochronous frame "
"lost (%d).\n", urb->iso_frame_desc[i].status);
continue;
}
src = urb->transfer_buffer + urb->iso_frame_desc[i].offset;
dest = myuvc_queue.mem + buf->buf.m.offset + buf->buf.bytesused;
len = urb->iso_frame_desc[i].actual_length;
/* 判断数据是否有效 */
/* URB数据含义:
* data[0] : 头部长度
* data[1] : 错误状态
*/
if (len < 2 || src[0] < 2 || src[0] > len)
continue;
/* Skip payloads marked with the error bit ("error frames"). */
if (src[1] & UVC_STREAM_ERR) {
printk("Dropping payload (error bit set).\n");
continue;
}
/* 除去头部后的数据长度 */
len -= src[0];
/* 缓冲区最多还能存多少数据 */
maxlen = buf->buf.length - buf->buf.bytesused;
nbytes = min(len, maxlen);
/* 复制数据 */
memcpy(dest, src + src[0], nbytes);
buf->buf.bytesused += nbytes;
/* 判断一帧数据是否已经全部接收到 */
if (len > maxlen) {
buf->state = VIDEOBUF_DONE;
}
/* Mark the buffer as done if the EOF marker is set. */
if (src[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
printk("Frame complete (EOF found).\n");
if (len == 0)
printk("EOF in empty payload.\n");
buf->state = VIDEOBUF_DONE;
}
}
/* 当接收完一帧数据,
* 从irqqueue中删除这个缓冲区
* 唤醒等待数据的进程
*/
if (buf->state == VIDEOBUF_DONE ||
buf->state == VIDEOBUF_ERROR)
{
list_del(&buf->irq);
wake_up(&buf->wait);
}
}
/* 再次提交URB */
if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
printk("Failed to resubmit video URB (%d).\n", ret);
}
}
/* 参考: uvc_init_video_isoc */
static int myuvc_alloc_init_urbs(void)
{
u16 psize;
u32 size;
int npackets;
int i;
int j;
struct urb *urb;
psize = wMaxPacketSize; /* 实时传输端点一次能传输的最大字节数 */
size = myuvc_params.dwMaxVideoFrameSize; /* 一帧数据的最大长度 */
npackets = DIV_ROUND_UP(size, psize);
if (npackets > 32)
npackets = 32;
size = myuvc_queue.urb_size = psize * npackets;
for (i = 0; i < MYUVC_URBS; ++i) {
/* 1. 分配usb_buffers */
myuvc_queue.urb_buffer[i] = usb_buffer_alloc(
myuvc_udev, size,
GFP_KERNEL | __GFP_NOWARN, &myuvc_queue.urb_dma[i]);
/* 2. 分配urb */
myuvc_queue.urb[i] = usb_alloc_urb(npackets, GFP_KERNEL);
if (!myuvc_queue.urb_buffer[i] || !myuvc_queue.urb[i])
{
myuvc_uninit_urbs();
return -ENOMEM;
}
}
/* 3. 设置urb */
for (i = 0; i < MYUVC_URBS; ++i) {
urb = myuvc_queue.urb[i];
urb->dev = myuvc_udev;
urb->context = NULL;
urb->pipe = usb_rcvisocpipe(myuvc_udev,myuvc_bEndpointAddress);
urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
urb->interval = 1;
urb->transfer_buffer = myuvc_queue.urb_buffer[i];
urb->transfer_dma = myuvc_queue.urb_dma[i];
urb->complete = myuvc_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;
}
}
return 0;
}
/* A11 启动传输
* 参考: uvc_video_enable(video, 1):
* uvc_commit_video
* uvc_init_video
*/
static int myuvc_vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
int ret;
/* 1. 向USB摄像头设置参数: 比如使用哪个format, 使用这个format下的哪个frame(分辨率)
* 参考: uvc_set_video_ctrl / uvc_get_video_ctrl
* 1.1 根据一个结构体uvc_streaming_control设置数据包: 可以手工设置,也可以读出后再修改
* 1.2 调用usb_control_msg发出数据包
*/
/* a. 测试参数 */
ret = myuvc_try_streaming_params(&myuvc_params);
printk("myuvc_try_streaming_params ret = %d\n", ret);
/* b. 取出参数 */
ret = myuvc_get_streaming_params(&myuvc_params);
printk("myuvc_get_streaming_params ret = %d\n", ret);
/* c. 设置参数 */
ret = myuvc_set_streaming_params(&myuvc_params);
printk("myuvc_set_streaming_params ret = %d\n", ret);
myuvc_print_streaming_params(&myuvc_params);
/* d. 设置VideoStreaming Interface所使用的setting
* d.1 从myuvc_params确定带宽
* d.2 根据setting的endpoint能传输的wMaxPacketSize
* 找到能满足该带宽的setting
*/
/* 手工确定:
* bandwidth = myuvc_params.dwMaxPayloadTransferSize = 1024
* 观察lsusb -v -d 0x1e4e:的结果:
* wMaxPacketSize 0x0400 1x 1024 bytes
* bAlternateSetting 8
*/
usb_set_interface(myuvc_udev, myuvc_streaming_intf, myuvc_streaming_bAlternateSetting);
/* 2. 分配设置URB */
ret = myuvc_alloc_init_urbs();
if (ret)
printk("myuvc_alloc_init_urbs err : ret = %d\n", ret);
/* 3. 提交URB以接收数据 */
for (i = 0; i < MYUVC_URBS; ++i) {
if ((ret = usb_submit_urb(myuvc_queue.urb[i], GFP_KERNEL)) < 0) {
printk("Failed to submit URB %u (%d).\n", i, ret);
myuvc_uninit_urbs();
return ret;
}
}
return 0;
}
/* A13 APP通过poll/select确定有数据后, 把缓存从队列中取出来
* 参考: uvc_dequeue_buffer
*/
static int myuvc_vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *v4l2_buf)
{
/* APP发现数据就绪后, 从mainqueue里取出这个buffer */
struct myuvc_buffer *buf;
int ret = 0;
if (list_empty(&myuvc_queue.mainqueue)) {
ret = -EINVAL;
goto done;
}
buf = list_first_entry(&myuvc_queue.mainqueue, struct myuvc_buffer, stream);
switch (buf->state) {
case VIDEOBUF_ERROR:
ret = -EIO;
case VIDEOBUF_DONE:
buf->state = VIDEOBUF_IDLE;
break;
case VIDEOBUF_IDLE:
case VIDEOBUF_QUEUED:
case VIDEOBUF_ACTIVE:
default:
ret = -EINVAL;
goto done;
}
list_del(&buf->stream);
done:
return ret;
}
/*
* A14 之前已经通过mmap映射了缓存, APP可以直接读数据
* A15 再次调用myuvc_vidioc_qbuf把缓存放入队列
* A16 poll...
*/
/* A17 停止
* 参考 : uvc_video_enable(video, 0)
*/
static int myuvc_vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type t)
{
struct urb *urb;
unsigned int i;
/* 1. kill URB */
for (i = 0; i < MYUVC_URBS; ++i) {
if ((urb = myuvc_queue.urb[i]) == NULL)
continue;
usb_kill_urb(urb);
}
/* 2. free URB */
myuvc_uninit_urbs();
/* 3. 设置VideoStreaming Interface为setting 0 */
usb_set_interface(myuvc_udev, myuvc_streaming_intf, 0);
return 0;
}
/* Control handling */
/* Extract the bit string specified by mapping->offset and mapping->size
* from the little-endian data stored at 'data' and return the result as
* a signed 32bit integer. Sign extension will be performed if the mapping
* references a signed data type.
*/
static __s32 myuvc_get_le_value(const __u8 *data)
{
int bits = 16;
int offset = 0;
__s32 value = 0;
__u8 mask;
data += offset / 8;
offset &= 7;
mask = ((1LL << bits) - 1) << offset;
for (; bits > 0; data++) {
__u8 byte = *data & mask;
value |= offset > 0 ? (byte >> offset) : (byte << (-offset));
bits -= 8 - (offset > 0 ? offset : 0);
offset -= 8;
mask = (1 << bits) - 1;
}
/* Sign-extend the value if needed. */
value |= -(value & (1 << (16 - 1)));
return value;
}
/* Set the bit string specified by mapping->offset and mapping->size
* in the little-endian data stored at 'data' to the value 'value'.
*/
static void myuvc_set_le_value(__s32 value, __u8 *data)
{
int bits = 16;
int offset = 0;
__u8 mask;
data += offset / 8;
offset &= 7;
for (; bits > 0; data++) {
mask = ((1LL << bits) - 1) << offset;
*data = (*data & ~mask) | ((value << offset) & mask);
value >>= offset ? offset : 8;
bits -= 8 - offset;
offset = 0;
}
}
/* 参考:uvc_query_v4l2_ctrl */
int myuvc_vidioc_queryctrl (struct file *file, void *fh,
struct v4l2_queryctrl *ctrl)
{
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
int ret;
u8 data[2];
if (ctrl->id != V4L2_CID_BRIGHTNESS)
return -EINVAL;
memset(ctrl, 0, sizeof *ctrl);
ctrl->id = V4L2_CID_BRIGHTNESS;
ctrl->type = V4L2_CTRL_TYPE_INTEGER;
strcpy(ctrl->name, "MyUVC_BRIGHTNESS");
ctrl->flags = 0;
pipe = usb_rcvctrlpipe(myuvc_udev, 0);
type |= USB_DIR_IN;
/* 发起USB传输确定这些值 */
ret = usb_control_msg(myuvc_udev, pipe, GET_MIN, type, PU_BRIGHTNESS_CONTROL << 8,
ProcessingUnitID << 8 | myuvc_control_intf, data, 2, 5000);
if (ret != 2)
return -EIO;
ctrl->minimum = myuvc_get_le_value(data); /* Note signedness */
ret = usb_control_msg(myuvc_udev, pipe, GET_MAX, type, PU_BRIGHTNESS_CONTROL << 8,
ProcessingUnitID << 8 | myuvc_control_intf, data, 2, 5000);
if (ret != 2)
return -EIO;
ctrl->maximum = myuvc_get_le_value(data); /* Note signedness */
ret = usb_control_msg(myuvc_udev, pipe, GET_RES, type, PU_BRIGHTNESS_CONTROL << 8,
ProcessingUnitID << 8 | myuvc_control_intf, data, 2, 5000);
if (ret != 2)
return -EIO;
ctrl->step = myuvc_get_le_value(data); /* Note signedness */
ret = usb_control_msg(myuvc_udev, pipe, GET_DEF, type, PU_BRIGHTNESS_CONTROL << 8,
ProcessingUnitID << 8 | myuvc_control_intf, data, 2, 5000);
if (ret != 2)
return -EIO;
ctrl->default_value = myuvc_get_le_value(data); /* Note signedness */
printk("Brightness: min =%d, max = %d, step = %d, default = %d\n", ctrl->minimum, ctrl->maximum, ctrl->step, ctrl->default_value);
return 0;
}
/* 参考 : uvc_ctrl_get */
int myuvc_vidioc_g_ctrl (struct file *file, void *fh,
struct v4l2_control *ctrl)
{
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
int ret;
u8 data[2];
if (ctrl->id != V4L2_CID_BRIGHTNESS)
return -EINVAL;
pipe = usb_rcvctrlpipe(myuvc_udev, 0);
type |= USB_DIR_IN;
ret = usb_control_msg(myuvc_udev, pipe, GET_CUR, type, PU_BRIGHTNESS_CONTROL << 8,
ProcessingUnitID << 8 | myuvc_control_intf, data, 2, 5000);
if (ret != 2)
return -EIO;
ctrl->value = myuvc_get_le_value(data); /* Note signedness */
return 0;
}
/* 参考: uvc_ctrl_set/uvc_ctrl_commit */
int myuvc_vidioc_s_ctrl (struct file *file, void *fh,
struct v4l2_control *ctrl)
{
__u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
unsigned int pipe;
int ret;
u8 data[2];
if (ctrl->id != V4L2_CID_BRIGHTNESS)
return -EINVAL;
myuvc_set_le_value(ctrl->value, data);
pipe = usb_sndctrlpipe(myuvc_udev, 0);
type |= USB_DIR_OUT;
ret = usb_control_msg(myuvc_udev, pipe, SET_CUR, type, PU_BRIGHTNESS_CONTROL << 8,
ProcessingUnitID << 8 | myuvc_control_intf, data, 2, 5000);
if (ret != 2)
return -EIO;
return 0;
}
static const struct v4l2_ioctl_ops myuvc_ioctl_ops = {
// 表示它是一个摄像头设备
.vidioc_querycap = myuvc_vidioc_querycap,
/* 用于列举、获得、测试、设置摄像头的数据的格式 */
.vidioc_enum_fmt_vid_cap = myuvc_vidioc_enum_fmt_vid_cap,
.vidioc_g_fmt_vid_cap = myuvc_vidioc_g_fmt_vid_cap,
.vidioc_try_fmt_vid_cap = myuvc_vidioc_try_fmt_vid_cap,
.vidioc_s_fmt_vid_cap = myuvc_vidioc_s_fmt_vid_cap,
/* 缓冲区操作: 申请/查询/放入队列/取出队列 */
.vidioc_reqbufs = myuvc_vidioc_reqbufs,
.vidioc_querybuf = myuvc_vidioc_querybuf,
.vidioc_qbuf = myuvc_vidioc_qbuf,
.vidioc_dqbuf = myuvc_vidioc_dqbuf,
/* 查询/获得/设置属性 */
.vidioc_queryctrl = myuvc_vidioc_queryctrl,
.vidioc_g_ctrl = myuvc_vidioc_g_ctrl,
.vidioc_s_ctrl = myuvc_vidioc_s_ctrl,
// 启动/停止
.vidioc_streamon = myuvc_vidioc_streamon,
.vidioc_streamoff = myuvc_vidioc_streamoff,
};
/* A1 */
static int myuvc_open(struct file *file)
{
return 0;
}
static void myuvc_vm_open(struct vm_area_struct *vma)
{
struct myuvc_buffer *buffer = vma->vm_private_data;
buffer->vma_use_count++;
}
static void myuvc_vm_close(struct vm_area_struct *vma)
{
struct myuvc_buffer *buffer = vma->vm_private_data;
buffer->vma_use_count--;
}
static struct vm_operations_struct myuvc_vm_ops = {
.open = myuvc_vm_open,
.close = myuvc_vm_close,
};
/* A9 把缓存映射到APP的空间,以后APP就可以直接操作这块缓存
* 参考: uvc_v4l2_mmap
*/
static int myuvc_mmap(struct file *file, struct vm_area_struct *vma)
{
struct myuvc_buffer *buffer;
struct page *page;
unsigned long addr, start, size;
unsigned int i;
int ret = 0;
start = vma->vm_start;
size = vma->vm_end - vma->vm_start;
/* 应用程序调用mmap函数时, 会传入offset参数
* 根据这个offset找出指定的缓冲区
*/
for (i = 0; i < myuvc_queue.count; ++i) {
buffer = &myuvc_queue.buffer[i];
if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
break;
}
if (i == myuvc_queue.count || size != myuvc_queue.buf_size) {
ret = -EINVAL;
goto done;
}
/*
* VM_IO marks the area as being an mmaped region for I/O to a
* device. It also prevents the region from being core dumped.
*/
vma->vm_flags |= VM_IO;
/* 根据虚拟地址找到缓冲区对应的page构体 */
addr = (unsigned long)myuvc_queue.mem + buffer->buf.m.offset;
while (size > 0) {
page = vmalloc_to_page((void *)addr);
/* 把page和APP传入的虚拟地址挂构 */
if ((ret = vm_insert_page(vma, start, page)) < 0)
goto done;
start += PAGE_SIZE;
addr += PAGE_SIZE;
size -= PAGE_SIZE;
}
vma->vm_ops = &myuvc_vm_ops;
vma->vm_private_data = buffer;
myuvc_vm_open(vma);
done:
return ret;
}
/* A12 APP调用POLL/select来确定缓存是否就绪(有数据)
* 参考 : uvc_v4l2_poll
*/
static unsigned int myuvc_poll(struct file *file, struct poll_table_struct *wait)
{
struct myuvc_buffer *buf;
unsigned int mask = 0;
/* 从mainqueuq中取出第1个缓冲区 */
/*判断它的状态, 如果未就绪, 休眠 */
if (list_empty(&myuvc_queue.mainqueue)) {
mask |= POLLERR;
goto done;
}
buf = list_first_entry(&myuvc_queue.mainqueue, struct myuvc_buffer, stream);
poll_wait(file, &buf->wait, wait);
if (buf->state == VIDEOBUF_DONE ||
buf->state == VIDEOBUF_ERROR)
mask |= POLLIN | POLLRDNORM;
done:
return mask;
}
/* A18 关闭 */
static int myuvc_close(struct file *file)
{
return 0;
}
static const struct v4l2_file_operations myuvc_fops = {
.owner = THIS_MODULE,
.open = myuvc_open,
.release = myuvc_close,
.mmap = myuvc_mmap,
.ioctl = video_ioctl2, /* V4L2 ioctl handler */
.poll = myuvc_poll,
};
static void myuvc_release(struct video_device *vdev)
{
}
static int myuvc_probe(struct usb_interface *intf,
const struct usb_device_id *id)
{
static int cnt = 0;
struct usb_device *dev = interface_to_usbdev(intf);
myuvc_udev = dev;
printk("myuvc_probe : cnt = %d\n", cnt++);
if (cnt == 1)
{
myuvc_control_intf = intf->cur_altsetting->desc.bInterfaceNumber;
}
else if (cnt == 2)
{
myuvc_streaming_intf = intf->cur_altsetting->desc.bInterfaceNumber;
}
if (cnt == 2)
{
/* 1. 分配一个video_device结构体 */
myuvc_vdev = video_device_alloc();
/* 2. 设置 */
/* 2.1 */
myuvc_vdev->release = myuvc_release;
/* 2.2 */
myuvc_vdev->fops = &myuvc_fops;
/* 2.3 */
myuvc_vdev->ioctl_ops = &myuvc_ioctl_ops;
/* 3. 注册 */
video_register_device(myuvc_vdev, VFL_TYPE_GRABBER, -1);
}
return 0;
}
static void myuvc_disconnect(struct usb_interface *intf)
{
static int cnt = 0;
printk("myuvc_disconnect : cnt = %d\n", cnt++);
if (cnt == 2)
{
video_unregister_device(myuvc_vdev);
video_device_release(myuvc_vdev);
}
}
static struct usb_device_id myuvc_ids[] = {
/* Generic USB Video Class */
{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) }, /* VideoControl Interface */
{ USB_INTERFACE_INFO(USB_CLASS_VIDEO, 2, 0) }, /* VideoStreaming Interface */
{}
};
/* 1. 分配usb_driver */
/* 2. 设置 */
static struct usb_driver myuvc_driver = {
.name = "myuvc",
.probe = myuvc_probe,
.disconnect = myuvc_disconnect,
.id_table = myuvc_ids,
};
static int myuvc_init(void)
{
/* 3. 注册 */
usb_register(&myuvc_driver);
return 0;
}
static void myuvc_exit(void)
{
usb_deregister(&myuvc_driver);
}
module_init(myuvc_init);
module_exit(myuvc_exit);
MODULE_LICENSE("GPL");
uvcvideo.h
#ifndef _USB_VIDEO_H_
#define _USB_VIDEO_H_
#include
#include
/*
* Dynamic controls
*/
/* Data types for UVC control data */
#define UVC_CTRL_DATA_TYPE_RAW 0
#define UVC_CTRL_DATA_TYPE_SIGNED 1
#define UVC_CTRL_DATA_TYPE_UNSIGNED 2
#define UVC_CTRL_DATA_TYPE_BOOLEAN 3
#define UVC_CTRL_DATA_TYPE_ENUM 4
#define UVC_CTRL_DATA_TYPE_BITMASK 5
/* Control flags */
#define UVC_CONTROL_SET_CUR (1 << 0)
#define UVC_CONTROL_GET_CUR (1 << 1)
#define UVC_CONTROL_GET_MIN (1 << 2)
#define UVC_CONTROL_GET_MAX (1 << 3)
#define UVC_CONTROL_GET_RES (1 << 4)
#define UVC_CONTROL_GET_DEF (1 << 5)
/* Control should be saved at suspend and restored at resume. */
#define UVC_CONTROL_RESTORE (1 << 6)
/* Control can be updated by the camera. */
#define UVC_CONTROL_AUTO_UPDATE (1 << 7)
#define UVC_CONTROL_GET_RANGE (UVC_CONTROL_GET_CUR | UVC_CONTROL_GET_MIN | \
UVC_CONTROL_GET_MAX | UVC_CONTROL_GET_RES | \
UVC_CONTROL_GET_DEF)
struct uvc_xu_control_info {
__u8 entity[16];
__u8 index;
__u8 selector;
__u16 size;
__u32 flags;
};
struct uvc_xu_control_mapping {
__u32 id;
__u8 name[32];
__u8 entity[16];
__u8 selector;
__u8 size;
__u8 offset;
enum v4l2_ctrl_type v4l2_type;
__u32 data_type;
};
struct uvc_xu_control {
__u8 unit;
__u8 selector;
__u16 size;
__u8 __user *data;
};
#define UVCIOC_CTRL_ADD _IOW('U', 1, struct uvc_xu_control_info)
#define UVCIOC_CTRL_MAP _IOWR('U', 2, struct uvc_xu_control_mapping)
#define UVCIOC_CTRL_GET _IOWR('U', 3, struct uvc_xu_control)
#define UVCIOC_CTRL_SET _IOW('U', 4, struct uvc_xu_control)
#ifdef __KERNEL__
#include
/* --------------------------------------------------------------------------
* UVC constants
*/
#define SC_UNDEFINED 0x00
#define SC_VIDEOCONTROL 0x01
#define SC_VIDEOSTREAMING 0x02
#define SC_VIDEO_INTERFACE_COLLECTION 0x03
#define PC_PROTOCOL_UNDEFINED 0x00
#define CS_UNDEFINED 0x20
#define CS_DEVICE 0x21
#define CS_CONFIGURATION 0x22
#define CS_STRING 0x23
#define CS_INTERFACE 0x24
#define CS_ENDPOINT 0x25
/* VideoControl class specific interface descriptor */
#define VC_DESCRIPTOR_UNDEFINED 0x00
#define VC_HEADER 0x01
#define VC_INPUT_TERMINAL 0x02
#define VC_OUTPUT_TERMINAL 0x03
#define VC_SELECTOR_UNIT 0x04
#define VC_PROCESSING_UNIT 0x05
#define VC_EXTENSION_UNIT 0x06
/* VideoStreaming class specific interface descriptor */
#define VS_UNDEFINED 0x00
#define VS_INPUT_HEADER 0x01
#define VS_OUTPUT_HEADER 0x02
#define VS_STILL_IMAGE_FRAME 0x03
#define VS_FORMAT_UNCOMPRESSED 0x04
#define VS_FRAME_UNCOMPRESSED 0x05
#define VS_FORMAT_MJPEG 0x06
#define VS_FRAME_MJPEG 0x07
#define VS_FORMAT_MPEG2TS 0x0a
#define VS_FORMAT_DV 0x0c
#define VS_COLORFORMAT 0x0d
#define VS_FORMAT_FRAME_BASED 0x10
#define VS_FRAME_FRAME_BASED 0x11
#define VS_FORMAT_STREAM_BASED 0x12
/* Endpoint type */
#define EP_UNDEFINED 0x00
#define EP_GENERAL 0x01
#define EP_ENDPOINT 0x02
#define EP_INTERRUPT 0x03
/* Request codes */
#define RC_UNDEFINED 0x00
#define SET_CUR 0x01
#define GET_CUR 0x81
#define GET_MIN 0x82
#define GET_MAX 0x83
#define GET_RES 0x84
#define GET_LEN 0x85
#define GET_INFO 0x86
#define GET_DEF 0x87
/* VideoControl interface controls */
#define VC_CONTROL_UNDEFINED 0x00
#define VC_VIDEO_POWER_MODE_CONTROL 0x01
#define VC_REQUEST_ERROR_CODE_CONTROL 0x02
/* Terminal controls */
#define TE_CONTROL_UNDEFINED 0x00
/* Selector Unit controls */
#define SU_CONTROL_UNDEFINED 0x00
#define SU_INPUT_SELECT_CONTROL 0x01
/* Camera Terminal controls */
#define CT_CONTROL_UNDEFINED 0x00
#define CT_SCANNING_MODE_CONTROL 0x01
#define CT_AE_MODE_CONTROL 0x02
#define CT_AE_PRIORITY_CONTROL 0x03
#define CT_EXPOSURE_TIME_ABSOLUTE_CONTROL 0x04
#define CT_EXPOSURE_TIME_RELATIVE_CONTROL 0x05
#define CT_FOCUS_ABSOLUTE_CONTROL 0x06
#define CT_FOCUS_RELATIVE_CONTROL 0x07
#define CT_FOCUS_AUTO_CONTROL 0x08
#define CT_IRIS_ABSOLUTE_CONTROL 0x09
#define CT_IRIS_RELATIVE_CONTROL 0x0a
#define CT_ZOOM_ABSOLUTE_CONTROL 0x0b
#define CT_ZOOM_RELATIVE_CONTROL 0x0c
#define CT_PANTILT_ABSOLUTE_CONTROL 0x0d
#define CT_PANTILT_RELATIVE_CONTROL 0x0e
#define CT_ROLL_ABSOLUTE_CONTROL 0x0f
#define CT_ROLL_RELATIVE_CONTROL 0x10
#define CT_PRIVACY_CONTROL 0x11
/* Processing Unit controls */
#define PU_CONTROL_UNDEFINED 0x00
#define PU_BACKLIGHT_COMPENSATION_CONTROL 0x01
#define PU_BRIGHTNESS_CONTROL 0x02
#define PU_CONTRAST_CONTROL 0x03
#define PU_GAIN_CONTROL 0x04
#define PU_POWER_LINE_FREQUENCY_CONTROL 0x05
#define PU_HUE_CONTROL 0x06
#define PU_SATURATION_CONTROL 0x07
#define PU_SHARPNESS_CONTROL 0x08
#define PU_GAMMA_CONTROL 0x09
#define PU_WHITE_BALANCE_TEMPERATURE_CONTROL 0x0a
#define PU_WHITE_BALANCE_TEMPERATURE_AUTO_CONTROL 0x0b
#define PU_WHITE_BALANCE_COMPONENT_CONTROL 0x0c
#define PU_WHITE_BALANCE_COMPONENT_AUTO_CONTROL 0x0d
#define PU_DIGITAL_MULTIPLIER_CONTROL 0x0e
#define PU_DIGITAL_MULTIPLIER_LIMIT_CONTROL 0x0f
#define PU_HUE_AUTO_CONTROL 0x10
#define PU_ANALOG_VIDEO_STANDARD_CONTROL 0x11
#define PU_ANALOG_LOCK_STATUS_CONTROL 0x12
#define LXU_MOTOR_PANTILT_RELATIVE_CONTROL 0x01
#define LXU_MOTOR_PANTILT_RESET_CONTROL 0x02
#define LXU_MOTOR_FOCUS_MOTOR_CONTROL 0x03
/* VideoStreaming interface controls */
#define VS_CONTROL_UNDEFINED 0x00
#define VS_PROBE_CONTROL 0x01
#define VS_COMMIT_CONTROL 0x02
#define VS_STILL_PROBE_CONTROL 0x03
#define VS_STILL_COMMIT_CONTROL 0x04
#define VS_STILL_IMAGE_TRIGGER_CONTROL 0x05
#define VS_STREAM_ERROR_CODE_CONTROL 0x06
#define VS_GENERATE_KEY_FRAME_CONTROL 0x07
#define VS_UPDATE_FRAME_SEGMENT_CONTROL 0x08
#define VS_SYNC_DELAY_CONTROL 0x09
#define TT_VENDOR_SPECIFIC 0x0100
#define TT_STREAMING 0x0101
/* Input Terminal types */
#define ITT_VENDOR_SPECIFIC 0x0200
#define ITT_CAMERA 0x0201
#define ITT_MEDIA_TRANSPORT_INPUT 0x0202
/* Output Terminal types */
#define OTT_VENDOR_SPECIFIC 0x0300
#define OTT_DISPLAY 0x0301
#define OTT_MEDIA_TRANSPORT_OUTPUT 0x0302
/* External Terminal types */
#define EXTERNAL_VENDOR_SPECIFIC 0x0400
#define COMPOSITE_CONNECTOR 0x0401
#define SVIDEO_CONNECTOR 0x0402
#define COMPONENT_CONNECTOR 0x0403
#define UVC_TERM_INPUT 0x0000
#define UVC_TERM_OUTPUT 0x8000
#define UVC_ENTITY_TYPE(entity) ((entity)->type & 0x7fff)
#define UVC_ENTITY_IS_UNIT(entity) (((entity)->type & 0xff00) == 0)
#define UVC_ENTITY_IS_TERM(entity) (((entity)->type & 0xff00) != 0)
#define UVC_ENTITY_IS_ITERM(entity) \
(((entity)->type & 0x8000) == UVC_TERM_INPUT)
#define UVC_ENTITY_IS_OTERM(entity) \
(((entity)->type & 0x8000) == UVC_TERM_OUTPUT)
#define UVC_STATUS_TYPE_CONTROL 1
#define UVC_STATUS_TYPE_STREAMING 2
/* ------------------------------------------------------------------------
* GUIDs
*/
#define UVC_GUID_UVC_CAMERA \
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01}
#define UVC_GUID_UVC_OUTPUT \
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02}
#define UVC_GUID_UVC_MEDIA_TRANSPORT_INPUT \
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x03}
#define UVC_GUID_UVC_PROCESSING \
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x01}
#define UVC_GUID_UVC_SELECTOR \
{0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, \
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x02}
#define UVC_GUID_LOGITECH_DEV_INFO \
{0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x1e}
#define UVC_GUID_LOGITECH_USER_HW \
{0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x1f}
#define UVC_GUID_LOGITECH_VIDEO \
{0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x50}
#define UVC_GUID_LOGITECH_MOTOR \
{0x82, 0x06, 0x61, 0x63, 0x70, 0x50, 0xab, 0x49, \
0xb8, 0xcc, 0xb3, 0x85, 0x5e, 0x8d, 0x22, 0x56}
#define UVC_GUID_FORMAT_MJPEG \
{ 'M', 'J', 'P', 'G', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
#define UVC_GUID_FORMAT_YUY2 \
{ 'Y', 'U', 'Y', '2', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
#define UVC_GUID_FORMAT_NV12 \
{ 'N', 'V', '1', '2', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
#define UVC_GUID_FORMAT_YV12 \
{ 'Y', 'V', '1', '2', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
#define UVC_GUID_FORMAT_I420 \
{ 'I', '4', '2', '0', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
#define UVC_GUID_FORMAT_UYVY \
{ 'U', 'Y', 'V', 'Y', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
#define UVC_GUID_FORMAT_Y800 \
{ 'Y', '8', '0', '0', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
#define UVC_GUID_FORMAT_BY8 \
{ 'B', 'Y', '8', ' ', 0x00, 0x00, 0x10, 0x00, \
0x80, 0x00, 0x00, 0xaa, 0x00, 0x38, 0x9b, 0x71}
/* ------------------------------------------------------------------------
* Driver specific constants.
*/
#define DRIVER_VERSION_NUMBER KERNEL_VERSION(0, 1, 0)
/* Number of isochronous URBs. */
#define UVC_URBS 5
/* Maximum number of packets per URB. */
#define UVC_MAX_PACKETS 32
/* Maximum number of video buffers. */
#define UVC_MAX_VIDEO_BUFFERS 32
/* Maximum status buffer size in bytes of interrupt URB. */
#define UVC_MAX_STATUS_SIZE 16
#define UVC_CTRL_CONTROL_TIMEOUT 300
#define UVC_CTRL_STREAMING_TIMEOUT 3000
/* Devices quirks */
#define UVC_QUIRK_STATUS_INTERVAL 0x00000001
#define UVC_QUIRK_PROBE_MINMAX 0x00000002
#define UVC_QUIRK_PROBE_EXTRAFIELDS 0x00000004
#define UVC_QUIRK_BUILTIN_ISIGHT 0x00000008
#define UVC_QUIRK_STREAM_NO_FID 0x00000010
#define UVC_QUIRK_IGNORE_SELECTOR_UNIT 0x00000020
#define UVC_QUIRK_FIX_BANDWIDTH 0x00000080
/* Format flags */
#define UVC_FMT_FLAG_COMPRESSED 0x00000001
#define UVC_FMT_FLAG_STREAM 0x00000002
/* ------------------------------------------------------------------------
* Structures.
*/
struct uvc_device;
/* TODO: Put the most frequently accessed fields at the beginning of
* structures to maximize cache efficiency.
*/
struct uvc_streaming_control {
__u16 bmHint;
__u8 bFormatIndex;
__u8 bFrameIndex;
__u32 dwFrameInterval;
__u16 wKeyFrameRate;
__u16 wPFrameRate;
__u16 wCompQuality;
__u16 wCompWindowSize;
__u16 wDelay;
__u32 dwMaxVideoFrameSize;
__u32 dwMaxPayloadTransferSize;
__u32 dwClockFrequency;
__u8 bmFramingInfo;
__u8 bPreferedVersion;
__u8 bMinVersion;
__u8 bMaxVersion;
};
struct uvc_menu_info {
__u32 value;
__u8 name[32];
};
struct uvc_control_info {
struct list_head list;
struct list_head mappings;
__u8 entity[16];
__u8 index;
__u8 selector;
__u16 size;
__u32 flags;
};
struct uvc_control_mapping {
struct list_head list;
struct uvc_control_info *ctrl;
__u32 id;
__u8 name[32];
__u8 entity[16];
__u8 selector;
__u8 size;
__u8 offset;
enum v4l2_ctrl_type v4l2_type;
__u32 data_type;
struct uvc_menu_info *menu_info;
__u32 menu_count;
__s32 (*get) (struct uvc_control_mapping *mapping, __u8 query,
const __u8 *data);
void (*set) (struct uvc_control_mapping *mapping, __s32 value,
__u8 *data);
};
struct uvc_control {
struct uvc_entity *entity;
struct uvc_control_info *info;
__u8 index; /* Used to match the uvc_control entry with a
uvc_control_info. */
__u8 dirty : 1,
loaded : 1,
modified : 1;
__u8 *data;
};
struct uvc_format_desc {
char *name;
__u8 guid[16];
__u32 fcc;
};
/* The term 'entity' refers to both UVC units and UVC terminals.
*
* The type field is either the terminal type (wTerminalType in the terminal
* descriptor), or the unit type (bDescriptorSubtype in the unit descriptor).
* As the bDescriptorSubtype field is one byte long, the type value will
* always have a null MSB for units. All terminal types defined by the UVC
* specification have a non-null MSB, so it is safe to use the MSB to
* differentiate between units and terminals as long as the descriptor parsing
* code makes sure terminal types have a non-null MSB.
*
* For terminals, the type's most significant bit stores the terminal
* direction (either UVC_TERM_INPUT or UVC_TERM_OUTPUT). The type field should
* always be accessed with the UVC_ENTITY_* macros and never directly.
*/
struct uvc_entity {
struct list_head list; /* Entity as part of a UVC device. */
struct list_head chain; /* Entity as part of a video device
* chain. */
__u8 id;
__u16 type;
char name[64];
union {
struct {
__u16 wObjectiveFocalLengthMin;
__u16 wObjectiveFocalLengthMax;
__u16 wOcularFocalLength;
__u8 bControlSize;
__u8 *bmControls;
} camera;
struct {
__u8 bControlSize;
__u8 *bmControls;
__u8 bTransportModeSize;
__u8 *bmTransportModes;
} media;
struct {
__u8 bSourceID;
} output;
struct {
__u8 bSourceID;
__u16 wMaxMultiplier;
__u8 bControlSize;
__u8 *bmControls;
__u8 bmVideoStandards;
} processing;
struct {
__u8 bNrInPins;
__u8 *baSourceID;
} selector;
struct {
__u8 guidExtensionCode[16];
__u8 bNumControls;
__u8 bNrInPins;
__u8 *baSourceID;
__u8 bControlSize;
__u8 *bmControls;
__u8 *bmControlsType;
} extension;
};
unsigned int ncontrols;
struct uvc_control *controls;
};
struct uvc_frame {
__u8 bFrameIndex;
__u8 bmCapabilities;
__u16 wWidth;
__u16 wHeight;
__u32 dwMinBitRate;
__u32 dwMaxBitRate;
__u32 dwMaxVideoFrameBufferSize;
__u8 bFrameIntervalType;
__u32 dwDefaultFrameInterval;
__u32 *dwFrameInterval;
};
struct uvc_format {
__u8 type;
__u8 index;
__u8 bpp;
__u8 colorspace;
__u32 fcc;
__u32 flags;
char name[32];
unsigned int nframes;
struct uvc_frame *frame;
};
struct uvc_streaming_header {
__u8 bNumFormats;
__u8 bEndpointAddress;
__u8 bTerminalLink;
__u8 bControlSize;
__u8 *bmaControls;
/* The following fields are used by input headers only. */
__u8 bmInfo;
__u8 bStillCaptureMethod;
__u8 bTriggerSupport;
__u8 bTriggerUsage;
};
struct uvc_streaming {
struct list_head list;
struct usb_interface *intf;
int intfnum;
__u16 maxpsize;
struct uvc_streaming_header header;
enum v4l2_buf_type type;
unsigned int nformats;
struct uvc_format *format;
struct uvc_streaming_control ctrl;
struct uvc_format *cur_format;
struct uvc_frame *cur_frame;
struct mutex mutex;
};
enum uvc_buffer_state {
UVC_BUF_STATE_IDLE = 0,
UVC_BUF_STATE_QUEUED = 1,
UVC_BUF_STATE_ACTIVE = 2,
UVC_BUF_STATE_DONE = 3,
UVC_BUF_STATE_ERROR = 4,
};
struct uvc_buffer {
unsigned long vma_use_count;
struct list_head stream;
/* Touched by interrupt handler. */
struct v4l2_buffer buf;
struct list_head queue;
wait_queue_head_t wait;
enum uvc_buffer_state state;
};
#define UVC_QUEUE_STREAMING (1 << 0)
#define UVC_QUEUE_DISCONNECTED (1 << 1)
#define UVC_QUEUE_DROP_INCOMPLETE (1 << 2)
struct uvc_video_queue {
enum v4l2_buf_type type;
void *mem;
unsigned int flags;
__u32 sequence;
unsigned int count;
unsigned int buf_size;
unsigned int buf_used;
struct uvc_buffer buffer[UVC_MAX_VIDEO_BUFFERS];
struct mutex mutex; /* protects buffers and mainqueue */
spinlock_t irqlock; /* protects irqqueue */
struct list_head mainqueue;
struct list_head irqqueue;
};
struct uvc_video_device {
struct uvc_device *dev;
struct video_device *vdev;
atomic_t active;
unsigned int frozen : 1;
struct list_head iterms; /* Input terminals */
struct uvc_entity *oterm; /* Output terminal */
struct uvc_entity *sterm; /* USB streaming terminal */
struct uvc_entity *processing;
struct uvc_entity *selector;
struct list_head extensions;
struct mutex ctrl_mutex;
struct uvc_video_queue queue;
/* Video streaming object, must always be non-NULL. */
struct uvc_streaming *streaming;
void (*decode) (struct urb *urb, struct uvc_video_device *video,
struct uvc_buffer *buf);
/* Context data used by the bulk completion handler. */
struct {
__u8 header[256];
unsigned int header_size;
int skip_payload;
__u32 payload_size;
__u32 max_payload_size;
} bulk;
struct urb *urb[UVC_URBS];
char *urb_buffer[UVC_URBS];
dma_addr_t urb_dma[UVC_URBS];
unsigned int urb_size;
__u8 last_fid;
};
enum uvc_device_state {
UVC_DEV_DISCONNECTED = 1,
};
struct uvc_device {
struct usb_device *udev;
struct usb_interface *intf;
unsigned long warnings;
__u32 quirks;
int intfnum;
char name[32];
enum uvc_device_state state;
struct kref kref;
struct list_head list;
atomic_t users;
/* Video control interface */
__u16 uvc_version;
__u32 clock_frequency;
struct list_head entities;
struct uvc_video_device video;
/* Status Interrupt Endpoint */
struct usb_host_endpoint *int_ep;
struct urb *int_urb;
__u8 *status;
struct input_dev *input;
char input_phys[64];
/* Video Streaming interfaces */
struct list_head streaming;
};
enum uvc_handle_state {
UVC_HANDLE_PASSIVE = 0,
UVC_HANDLE_ACTIVE = 1,
};
struct uvc_fh {
struct uvc_video_device *device;
enum uvc_handle_state state;
};
struct uvc_driver {
struct usb_driver driver;
struct mutex open_mutex; /* protects from open/disconnect race */
struct list_head devices; /* struct uvc_device list */
struct list_head controls; /* struct uvc_control_info list */
struct mutex ctrl_mutex; /* protects controls and devices
lists */
};
/* ------------------------------------------------------------------------
* Debugging, printing and logging
*/
#define UVC_TRACE_PROBE (1 << 0)
#define UVC_TRACE_DESCR (1 << 1)
#define UVC_TRACE_CONTROL (1 << 2)
#define UVC_TRACE_FORMAT (1 << 3)
#define UVC_TRACE_CAPTURE (1 << 4)
#define UVC_TRACE_CALLS (1 << 5)
#define UVC_TRACE_IOCTL (1 << 6)
#define UVC_TRACE_FRAME (1 << 7)
#define UVC_TRACE_SUSPEND (1 << 8)
#define UVC_TRACE_STATUS (1 << 9)
#define UVC_WARN_MINMAX 0
#define UVC_WARN_PROBE_DEF 1
extern unsigned int uvc_no_drop_param;
extern unsigned int uvc_trace_param;
extern unsigned int uvc_timeout_param;
#define uvc_trace(flag, msg...) \
do { \
if (uvc_trace_param & flag) \
printk(KERN_DEBUG "uvcvideo: " msg); \
} while (0)
#define uvc_warn_once(dev, warn, msg...) \
do { \
if (!test_and_set_bit(warn, &dev->warnings)) \
printk(KERN_INFO "uvcvideo: " msg); \
} while (0)
#define uvc_printk(level, msg...) \
printk(level "uvcvideo: " msg)
#define UVC_GUID_FORMAT "%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-" \
"%02x%02x%02x%02x%02x%02x"
#define UVC_GUID_ARGS(guid) \
(guid)[3], (guid)[2], (guid)[1], (guid)[0], \
(guid)[5], (guid)[4], \
(guid)[7], (guid)[6], \
(guid)[8], (guid)[9], \
(guid)[10], (guid)[11], (guid)[12], \
(guid)[13], (guid)[14], (guid)[15]
/* --------------------------------------------------------------------------
* Internal functions.
*/
/* Core driver */
extern struct uvc_driver uvc_driver;
extern void uvc_delete(struct kref *kref);
/* Video buffers queue management. */
extern void uvc_queue_init(struct uvc_video_queue *queue,
enum v4l2_buf_type type);
extern int uvc_alloc_buffers(struct uvc_video_queue *queue,
unsigned int nbuffers, unsigned int buflength);
extern int uvc_free_buffers(struct uvc_video_queue *queue);
extern int uvc_query_buffer(struct uvc_video_queue *queue,
struct v4l2_buffer *v4l2_buf);
extern int uvc_queue_buffer(struct uvc_video_queue *queue,
struct v4l2_buffer *v4l2_buf);
extern int uvc_dequeue_buffer(struct uvc_video_queue *queue,
struct v4l2_buffer *v4l2_buf, int nonblocking);
extern int uvc_queue_enable(struct uvc_video_queue *queue, int enable);
extern void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect);
extern struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue,
struct uvc_buffer *buf);
extern unsigned int uvc_queue_poll(struct uvc_video_queue *queue,
struct file *file, poll_table *wait);
extern int uvc_queue_allocated(struct uvc_video_queue *queue);
static inline int uvc_queue_streaming(struct uvc_video_queue *queue)
{
return queue->flags & UVC_QUEUE_STREAMING;
}
/* V4L2 interface */
extern const struct v4l2_file_operations uvc_fops;
/* Video */
extern int uvc_video_init(struct uvc_video_device *video);
extern int uvc_video_suspend(struct uvc_video_device *video);
extern int uvc_video_resume(struct uvc_video_device *video);
extern int uvc_video_enable(struct uvc_video_device *video, int enable);
extern int uvc_probe_video(struct uvc_video_device *video,
struct uvc_streaming_control *probe);
extern int uvc_commit_video(struct uvc_video_device *video,
struct uvc_streaming_control *ctrl);
extern int uvc_query_ctrl(struct uvc_device *dev, __u8 query, __u8 unit,
__u8 intfnum, __u8 cs, void *data, __u16 size);
/* Status */
extern int uvc_status_init(struct uvc_device *dev);
extern void uvc_status_cleanup(struct uvc_device *dev);
extern int uvc_status_start(struct uvc_device *dev);
extern void uvc_status_stop(struct uvc_device *dev);
extern int uvc_status_suspend(struct uvc_device *dev);
extern int uvc_status_resume(struct uvc_device *dev);
/* Controls */
extern struct uvc_control *uvc_find_control(struct uvc_video_device *video,
__u32 v4l2_id, struct uvc_control_mapping **mapping);
extern int uvc_query_v4l2_ctrl(struct uvc_video_device *video,
struct v4l2_queryctrl *v4l2_ctrl);
extern int uvc_ctrl_add_info(struct uvc_control_info *info);
extern int uvc_ctrl_add_mapping(struct uvc_control_mapping *mapping);
extern int uvc_ctrl_init_device(struct uvc_device *dev);
extern void uvc_ctrl_cleanup_device(struct uvc_device *dev);
extern int uvc_ctrl_resume_device(struct uvc_device *dev);
extern void uvc_ctrl_init(void);
extern int uvc_ctrl_begin(struct uvc_video_device *video);
extern int __uvc_ctrl_commit(struct uvc_video_device *video, int rollback);
static inline int uvc_ctrl_commit(struct uvc_video_device *video)
{
return __uvc_ctrl_commit(video, 0);
}
static inline int uvc_ctrl_rollback(struct uvc_video_device *video)
{
return __uvc_ctrl_commit(video, 1);
}
extern int uvc_ctrl_get(struct uvc_video_device *video,
struct v4l2_ext_control *xctrl);
extern int uvc_ctrl_set(struct uvc_video_device *video,
struct v4l2_ext_control *xctrl);
extern int uvc_xu_ctrl_query(struct uvc_video_device *video,
struct uvc_xu_control *ctrl, int set);
/* Utility functions */
extern void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,
unsigned int n_terms, unsigned int threshold);
extern uint32_t uvc_fraction_to_interval(uint32_t numerator,
uint32_t denominator);
extern struct usb_host_endpoint *uvc_find_endpoint(
struct usb_host_interface *alts, __u8 epaddr);
/* Quirks support */
void uvc_video_decode_isight(struct urb *urb, struct uvc_video_device *video,
struct uvc_buffer *buf);
#endif /* __KERNEL__ */
#endif
Makefile:
KERN_DIR = /usr/src/linux-headers-2.6.31-14-generic
all:
make -C $(KERN_DIR) M=`pwd` modules
clean:
make -C $(KERN_DIR) M=`pwd` modules clean
rm -rf modules.order
obj-m += myuvc.o
驱动移植好了，插上摄像头，执行lsusb就可以看到摄像头数据，或者在 ls /dev/video0 就是摄像头驱动的设备节点，下面我讲解开发过程可以选择的应用程序。
Servfox，Spcaview和luvcview。这三个都可以实现的，我也写了一个应用程序来测试摄像头数据，是在LCD上显示摄像头数据，首先需要移植好LCD驱动程序。