自己写的uvc驱动支持IP2977/ip2970-优快云博客

本文链接：https://blog.youkuaiyun.com/u011677209/article/details/79541197

/* 作者: 453411484@qq.com
* 此驱动程序是基于linux2.6.31.14内核
* 上一篇自己写的uvc驱动程序是针对环宇飞扬6190来写的，有一些缺点，这些缺点在本次的驱动
* 中进行了修改此uvc驱动是针对IP2977进行了支持，根据IP2977芯片厂商提供的修改手册进行了修改。
* 此驱动程序虽然支持IP2977摄像头，但是显示效果不太好，此驱动只是针对学习使用。
*/
#include <linux kernel="" 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 <linux mm="" h="">
#include <asm atomic="" h="">
#include <asm unaligned="" h="">
#include <media v4l2-common="" h="">
#include <media v4l2-ioctl="" h="">
#include <media videobuf-core="" h="">
#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 = 0x82;
static int myuvc_streaming_intf;
static int myuvc_control_intf;
static struct v4l2_format myuvc_format;
static struct frame_desc frames[] = { {640, 480}, {320, 240}, {160, 120}};
static int frame_idx = 1;
static int bBitsPerPixel = 0; /* lsusb -v -d 0x1e4e: "bBitsPerPixel" */
static int uvc_version = 0x0100; /* lsusb -v -d 0x1b3b: bcdUVC */
static int ProcessingUnitID = 3; /* lsusb -v -d 0x1b3b: PROCESSING_UNIT */
/* 以后再设置 */
static int wMaxPacketSize = 800;
static int myuvc_streaming_bAlternateSetting = 5;
static int dwMaxVideoFrameSize = 77312;
static struct myuvc_streaming_control myuvc_params;
static int last_fid = -1;
/* 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;
strcpy(f->description, "MJPEG");
f->pixelformat = V4L2_PIX_FMT_MJPEG;
//f->flags = ;
f->type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
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_MJPEG)
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;
/* 对于MJPEG数据类型来说，bBitsPerPixel是无法知道的。因此我们设为0 */
f->fmt.pix.bytesperline =
(f->fmt.pix.width * bBitsPerPixel) >> 3;
/* 一帧数据最大为dwMaxVideoFrameSize=77312,是由确定带宽时确定出来的。 */
f->fmt.pix.sizeimage = dwMaxVideoFrameSize;
f->fmt.pix.field = V4L2_FIELD_NONE;
/* 由描述符bColorPrimaries 1 (BT.709,sRGB)可知 */
f->fmt.pix.colorspace = V4L2_COLORSPACE_SRGB;
f->fmt.pix.priv = 0; /* private data, depends on pixelformat */
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.