仿照内核的自带UVC（usb video class）驱动程序写的一版简化驱动，仅供学习，实际项目开发中应该尽量使用内核自带的驱动，除非内核自带的驱动不支持此款硬件才需要自己写驱动。
下面就直接上代码了，要根据自己的设备信息修改相关配置参数。
1 #include <linux/kernel.h>
2 #include <linux/list.h>
3 #include <linux/module.h>
4 #include <linux/usb.h>
5 #include <linux/videodev2.h>
6 #include <linux/vmalloc.h>
7 #include <linux/wait.h>
8 #include <linux/mm.h>
9 #include <asm/atomic.h>
10 #include <asm/unaligned.h>
11
12 #include <media/v4l2-common.h>
13 #include <media/v4l2-ioctl.h>
14 #include <media/videobuf-core.h>
15
16 #include "uvcvideo.h"
17
18 #define sheldon_UVC_URBS 3
19
20
21 /* Values for bmHeaderInfo (Video and Still Image Payload Headers, 2.4.3.3) */
22 #define UVC_STREAM_EOH (1 << 7)
23 #define UVC_STREAM_ERR (1 << 6)
24 #define UVC_STREAM_STI (1 << 5)
25 #define UVC_STREAM_RES (1 << 4)
26 #define UVC_STREAM_SCR (1 << 3)
27 #define UVC_STREAM_PTS (1 << 2)
28 #define UVC_STREAM_EOF (1 << 1)
29 #define UVC_STREAM_FID (1 << 0)
30
31
32 struct sheldon_uvc_streaming_control {
33 __u16 bmHint;
34 __u8 bFormatIndex;
35 __u8 bFrameIndex;
36 __u32 dwFrameInterval;
37 __u16 wKeyFrameRate;
38 __u16 wPFrameRate;
39 __u16 wCompQuality;
40 __u16 wCompWindowSize;
41 __u16 wDelay;
42 __u32 dwMaxVideoFrameSize;
43 __u32 dwMaxPayloadTransferSize;
44 __u32 dwClockFrequency;
45 __u8 bmFramingInfo;
46 __u8 bPreferedVersion;
47 __u8 bMinVersion;
48 __u8 bMaxVersion;
49 };
50
51
52
53 /*参考 drivers/media/video/uvc 下一系列代码*/
54
55 struct frame_desc {
56 int width;
57 int height;
58 };
59
60 /* 参考uvc_video_queue定义一些结构体 */
61 struct sheldon_uvc_buffer {
62 struct v4l2_buffer buf;
63 int state;
64 int vma_use_count; /* 表示是否已经被mmap */
65 wait_queue_head_t wait; /* APP要读某个缓冲区,如果无数据,在此休眠 */
66 struct list_head stream;
67 struct list_head irq;
68 };
69
70 struct sheldon_uvc_queue {
71 void *mem;
72 int count;
73 int buf_size;
74 struct sheldon_uvc_buffer buffer[32];
75
76 struct urb *urb[32];
77 char *urb_buffer[32];
78 dma_addr_t urb_dma[32];
79 unsigned int urb_size;
80
81 struct list_head mainqueue; /* 供APP消费用 */
82 struct list_head irqqueue; /* 供底层驱动生产用 */
83 };
84
85 static struct sheldon_uvc_queue sheldon_uvc_queue;
86
87 static struct video_device *sheldon_uvc_vdev;
88 static struct usb_device *sheldon_uvc_udev;
89 static int sheldon_uvc_bEndpointAddress = 0x82; //lsusb - 人工确定参数
90 static int sheldon_uvc_streaming_intf;
91 static int sheldon_uvc_control_intf;
92 static int sheldon_uvc_streaming_bAlternateSetting = 1;
93 static struct v4l2_format sheldon_uvc_format;
94 static struct frame_desc framdesc[] = {{640,480},{320,240},{160,120}};//{{640, 480}, {352, 288}, {320, 240}, {176, 144}, {160, 120}};
95 static int frame_idx = 1;
96 static int bBitsPerPixel = 16; /* lsusb -v -d 0x1e4e: "bBitsPerPixel" */
97 static int uvc_version = 0x0100; /* lsusb -v -d 0x1e4e: bcdUVC */
98 static int wMaxPacketSize = 128;
99 static int ProcessingUnitID = 5;
100
101 static struct sheldon_uvc_streaming_control sheldon_uvc_params;
102
103
104 /* A2 参考 uvc_v4l2_do_ioctl */
105
106 /* sheldonUV_vidioc_querycap :用于判断是否为视频设备*/
107 static int sheldonUV_vidioc_querycap(struct file *file, void *priv,
108 struct v4l2_capability *cap)
109 {
110 //strcpy(cap->driver, "sheldonUV");
111 //strcpy(cap->card, "sheldonUV");
112 //cap->version = 0x0001;
113 //cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
114
115
116 memset(cap, 0, sizeof *cap);
117 strcpy(cap->driver, "sheldonUV");
118 strcpy(cap->card, "sheldonUV");
119
120 cap->version = 1;
121 cap->capabilities = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
122
123 return 0;
124 }
125
126
127 /* A3 列举支持哪种格式
128 * 参考: uvc_fmts 数组
129 */
130 static int sheldonUV_vidioc_enum_fmt_vid_cap(struct file *file, void *priv,
131 struct v4l2_fmtdesc *f)
132 {
133 /* 人工查看描述符可知我们用的摄像头只支持1种格式 */
134 if (f->index >= 1)
135 return -EINVAL;
136
137 /* 支持什么格式呢?
138 * 查看VideoStreaming Interface的描述符,
139 * ‘Y‘‘U‘‘Y‘‘V‘
140 * 得到GUID为"59 55 59 32 00 00 10 00 80 00 00 aa 00 38 9b 71"
141 */
142 strcpy(f->description, "4:2:2, packed, YUYV");
143 f->pixelformat = V4L2_PIX_FMT_YUYV;
144
145 return 0;
146 }
147
148 /* A4 返回当前所使用的格式 */
149 static int sheldonUV_vidioc_get_fmt_vid_cap(struct file *file, void *priv,
150 struct v4l2_format *f)
151 {
152 memcpy(f, &sheldon_uvc_format, sizeof(sheldon_uvc_format));
153 return (0);
154 }
155
156 /* A5 测试驱动程序是否支持某种格式 ，强制设置为第一种格式
157 * 参考: uvc_v4l2_try_format
158 * sheldon_vivi_vidioc_try_fmt_vid_cap
159 */
160
161 static int sheldonUV_vidioc_try_fmt_vid_cap(struct file *file, void *priv,
162 struct v4l2_format *f)
163 {
164 if (f->type != V4L2_BUF_TYPE_VIDEO_CAPTURE)
165 {
166 return -EINVAL;
167 }
168
169 if (f->fmt.pix.pixelformat != V4L2_PIX_FMT_YUYV)
170 return -EINVAL;
171
172 /* 调整format的width, height,
173 * 计算bytesperline, sizeimage
174 */
175
176 /* 人工查看描述符, 确定支持哪几种分辨率 */
177 f->fmt.pix.width = framdesc[frame_idx].width;
178 f->fmt.pix.height = framdesc[frame_idx].height;
179 f->fmt.pix.bytesperline =
180 (f->fmt.pix.width * bBitsPerPixel) >> 3;
181 f->fmt.pix.sizeimage =
182 f->fmt.pix.height * f->fmt.pix.bytesperline;
183
184
185 return 0;
186 }
187
188
189
190 /* A6 如果支持这种格式,则进行设置-参考 vivi_vidioc_s_fmt_vid_cap*/
191 static int sheldonUV_vidioc_set_fmt_vid_cap(struct file *file, void *priv,
192 struct v4l2_format *f)
193 {
194 int ret = sheldonUV_vidioc_try_fmt_vid_cap(file, NULL, f);
195 if (ret < 0)
196 return ret;
197
198 memcpy(&sheldon_uvc_format, f, sizeof(sheldon_uvc_format));
199
200 return 0;// ret;
201 }
202
203 static int sheldon_uvc_free_buffers(void)
204 {
205 if (sheldon_uvc_queue.mem)
206 {
207 vfree(sheldon_uvc_queue.mem);
208 memset(&sheldon_uvc_queue, 0, sizeof(sheldon_uvc_queue));
209 sheldon_uvc_queue.mem = NULL;
210 }
211 return 0;
212 }
213
214
215 /* A7 APP 调用该ioctl让驱动程分配若干个缓存，APP将从这些缓存中读到视频数据
216 * 参考: uvc_alloc_buffers
217 */
218 static int sheldonUV_vidioc_reqbufs(struct file *file, void *priv,
219 struct v4l2_requestbuffers *p)
220 {
221 int nbuffers = p->count;
222 int bufsize = PAGE_ALIGN(sheldon_uvc_format.fmt.pix.sizeimage);
223 unsigned int i;
224 void *mem = NULL;
225 int ret;
226
227 if ((ret = sheldon_uvc_free_buffers()) < 0)
228 goto done;
229
230 /* Bail out if no buffers should be allocated. */
231 if (nbuffers == 0)
232 goto done;
233
234 /* Decrement the number of buffers until allocation succeeds. */
235 for (; nbuffers > 0; --nbuffers) {
236 mem = vmalloc_32(nbuffers * bufsize);
237 if (mem != NULL)
238 break;
239 }
240
241 if (mem == NULL) {
242 ret = -ENOMEM;
243 goto done;
244 }
245
246 /* 这些缓存是一次性作为一个整体来分配的 */
247 memset(&sheldon_uvc_queue, 0, sizeof(sheldon_uvc_queue));
248
249 INIT_LIST_HEAD(&sheldon_uvc_queue.mainqueue);
250 INIT_LIST_HEAD(&sheldon_uvc_queue.irqqueue);
251
252 for (i = 0; i < nbuffers; ++i) {
253 sheldon_uvc_queue.buffer[i].buf.index = i;
254 sheldon_uvc_queue.buffer[i].buf.m.offset = i * bufsize;
255 sheldon_uvc_queue.buffer[i].buf.length = sheldon_uvc_format.fmt.pix.sizeimage;
256 sheldon_uvc_queue.buffer[i].buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE;
257 sheldon_uvc_queue.buffer[i].buf.sequence = 0;
258 sheldon_uvc_queue.buffer[i].buf.field = V4L2_FIELD_NONE;
259 sheldon_uvc_queue.buffer[i].buf.memory = V4L2_MEMORY_MMAP;
260 sheldon_uvc_queue.buffer[i].buf.flags = 0;
261 sheldon_uvc_queue.buffer[i].state = VIDEOBUF_IDLE; //分配好后为空闲状态
262 init_waitqueue_head(&sheldon_uvc_queue.buffer[i].wait);
263 }
264
265 sheldon_uvc_queue.mem = mem;
266 sheldon_uvc_queue.count = nbuffers;
267 sheldon_uvc_queue.buf_size = bufsize;
268 ret = nbuffers;
269
270 done:
271 return ret;
272 }
273
274
275
276 /*A8 查询buffer状态，获得偏移值,app可以调用mmap*/
277 static int sheldonUV_vidioc_querybuf(struct file *file, void *priv, struct v4l2_buffer *v4l2_buf)
278 {
279 int ret = 0;
280
281 if (v4l2_buf->index >= sheldon_uvc_queue.count) {
282 ret = -EINVAL;
283 goto done;
284 }
285
286 memcpy(v4l2_buf, &sheldon_uvc_queue.buffer[v4l2_buf->index].buf, sizeof(*v4l2_buf));
287
288 /* 更新flags */
289 if (sheldon_uvc_queue.buffer[v4l2_buf->index].vma_use_count)
290 v4l2_buf->flags |= V4L2_BUF_FLAG_MAPPED;
291
292
293 switch (sheldon_uvc_queue.buffer[v4l2_buf->index].state) {
294 case VIDEOBUF_ERROR:
295 case VIDEOBUF_DONE:
296 v4l2_buf->flags |= V4L2_BUF_FLAG_DONE;
297 break;
298 case VIDEOBUF_QUEUED:
299 case VIDEOBUF_ACTIVE:
300 v4l2_buf->flags |= V4L2_BUF_FLAG_QUEUED;
301 break;
302 case VIDEOBUF_IDLE:
303 default:
304 break;
305 }
306
307 done:
308 return ret;
309 }
310
311
312 /* 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
313 * 参考: uvc_queue_buffer
314 */
315 static int sheldonUV_vidioc_qbuf(struct file *file, void *priv, struct v4l2_buffer *v4l2_buf)
316 {
317 struct sheldon_uvc_buffer *buf;
318
319 /* 0. APP传入的v4l2_buf可能有问题, 要做判断 */
320
321 if (v4l2_buf->type != V4L2_BUF_TYPE_VIDEO_CAPTURE ||
322 v4l2_buf->memory != V4L2_MEMORY_MMAP) {
323 return -EINVAL;
324 }
325
326 if (v4l2_buf->index >= sheldon_uvc_queue.count) {
327 return -EINVAL;
328 }
329
330 buf = &sheldon_uvc_queue.buffer[v4l2_buf->index];
331
332 if (buf->state != VIDEOBUF_IDLE) {
333 return -EINVAL;
334 }
335
336
337 /* 1. 修改状态 */
338 buf->state = VIDEOBUF_QUEUED;
339 buf->buf.bytesused = 0;
340
341 /* 2. 放入2个队列 */
342 /* 队列1: 供APP使用
343 * 当缓冲区没有数据时,放入mainqueue队列
344 * 当缓冲区有数据时, APP从mainqueue队列中取出
345 */
346 list_add_tail(&buf->stream, &sheldon_uvc_queue.mainqueue);
347
348 /* 队列2: 供产生数据的函数使用
349 * 当采集到数据时,从irqqueue队列中取出第1个缓冲区,存入数据
350 */
351 list_add_tail(&buf->irq, &sheldon_uvc_queue.irqqueue);
352
353 return 0;
354
355 }
356
357
358 static void sheldon_uvc_print_streaming_params(struct sheldon_uvc_streaming_control *ctrl)
359 {
360 printk("video params:\n");
361 printk("bmHint = %d\n", ctrl->bmHint);
362 printk("bFormatIndex = %d\n", ctrl->bFormatIndex);
363 printk("bFrameIndex = %d\n", ctrl->bFrameIndex);
364 printk("dwFrameInterval = %d\n", ctrl->dwFrameInterval);
365 printk("wKeyFrameRate = %d\n", ctrl->wKeyFrameRate);
366 printk("wPFrameRate = %d\n", ctrl->wPFrameRate);
367 printk("wCompQuality = %d\n", ctrl->wCompQuality);
368 printk("wCompWindowSize = %d\n", ctrl->wCompWindowSize);
369 printk("wDelay = %d\n", ctrl->wDelay);
370 printk("dwMaxVideoFrameSize = %d\n", ctrl->dwMaxVideoFrameSize);
371 printk("dwMaxPayloadTransferSize = %d\n", ctrl->dwMaxPayloadTransferSize);
372 printk("dwClockFrequency = %d\n", ctrl->dwClockFrequency);
373 printk("bmFramingInfo = %d\n", ctrl->bmFramingInfo);
374 printk("bPreferedVersion = %d\n", ctrl->bPreferedVersion);
375 printk("bMinVersion = %d\n", ctrl->bMinVersion);
376 printk("bMinVersion = %d\n", ctrl->bMinVersion);
377 }
378
379
380 /* 参考: uvc_get_video_ctrl
381 (ret = uvc_get_video_ctrl(video, probe, 1, GET_CUR))
382 static int uvc_get_video_ctrl(struct uvc_video_device *video,
383 struct uvc_streaming_control *ctrl, int probe, __u8 query)
384 */
385 static int sheldon_uvc_get_streaming_params(struct sheldon_uvc_streaming_control *ctrl)
386 {
387 __u8 *data;
388 __u16 size;
389 int ret;
390 __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
391 unsigned int pipe;
392
393 size = uvc_version >= 0x0110 ? 34 : 26;
394 data = kmalloc(size, GFP_KERNEL);
395 if (data == NULL)
396 return -ENOMEM;
397
398 pipe = (GET_CUR & 0x80) ? usb_rcvctrlpipe(sheldon_uvc_udev, 0)
399 : usb_sndctrlpipe(sheldon_uvc_udev, 0);
400 type |= (GET_CUR & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
401
402 ret = usb_control_msg(sheldon_uvc_udev, pipe, GET_CUR, type, VS_PROBE_CONTROL << 8,
403 0 << 8 | sheldon_uvc_streaming_intf, data, size, 5000);
404
405 if (ret < 0)
406 goto done;
407
408 ctrl->bmHint = le16_to_cpup((__le16 *)&data[0]);
409 ctrl->bFormatIndex = data[2];
410 ctrl->bFrameIndex = data[3];
411 ctrl->dwFrameInterval = le32_to_cpup((__le32 *)&data[4]);
412 ctrl->wKeyFrameRate = le16_to_cpup((__le16 *)&data[8]);
413 ctrl->wPFrameRate = le16_to_cpup((__le16 *)&data[10]);
414 ctrl->wCompQuality = le16_to_cpup((__le16 *)&data[12]);
415 ctrl->wCompWindowSize = le16_to_cpup((__le16 *)&data[14]);
416 ctrl->wDelay = le16_to_cpup((__le16 *)&data[16]);
417 ctrl->dwMaxVideoFrameSize = get_unaligned_le32(&data[18]);
418 ctrl->dwMaxPayloadTransferSize = get_unaligned_le32(&data[22]);
419
420 if (size == 34) {
421 ctrl->dwClockFrequency = get_unaligned_le32(&data[26]);
422 ctrl->bmFramingInfo = data[30];
423 ctrl->bPreferedVersion = data[31];
424 ctrl->bMinVersion = data[32];
425 ctrl->bMaxVersion = data[33];
426 } else {
427 //ctrl->dwClockFrequency = video->dev->clock_frequency;
428 ctrl->bmFramingInfo = 0;
429 ctrl->bPreferedVersion = 0;
430 ctrl->bMinVersion = 0;
431 ctrl->bMaxVersion = 0;
432 }
433
434 done:
435 kfree(data);
436
437 return (ret < 0) ? ret : 0;
438 }
439
440
441 /* 参考: uvc_v4l2_try_format ∕uvc_probe_video
442 * uvc_set_video_ctrl(video, probe, 1)
443 */
444 static int sheldon_uvc_try_streaming_params(struct sheldon_uvc_streaming_control *ctrl)
445 {
446 __u8 *data;
447 __u16 size;
448 int ret;
449 __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
450 unsigned int pipe;
451
452 memset(ctrl, 0, sizeof *ctrl);
453
454 ctrl->bmHint = 1; /* dwFrameInterval */
455 ctrl->bFormatIndex = 1;
456 ctrl->bFrameIndex = frame_idx + 1;
457 ctrl->dwFrameInterval = 333333;
458
459
460 size = uvc_version >= 0x0110 ? 34 : 26;
461 data = kzalloc(size, GFP_KERNEL);
462
463
464 if (data == NULL)
465 return -ENOMEM;
466
467
468 *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
469 data[2] = ctrl->bFormatIndex;
470 data[3] = ctrl->bFrameIndex;
471 *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
472 *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
473 *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
474 *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
475 *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
476 *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
477 put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
478 put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
479
480
481 if (size == 34) {
482 put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
483 data[30] = ctrl->bmFramingInfo;
484 data[31] = ctrl->bPreferedVersion;
485 data[32] = ctrl->bMinVersion;
486 data[33] = ctrl->bMaxVersion;
487 }
488
489
490 pipe = (SET_CUR & 0x80) ? usb_rcvctrlpipe(sheldon_uvc_udev, 0)
491 : usb_sndctrlpipe(sheldon_uvc_udev, 0);
492
493
494 type |= (SET_CUR & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
495
496 ret = usb_control_msg(sheldon_uvc_udev, pipe, SET_CUR, type, VS_PROBE_CONTROL << 8,
497 0 << 8 | sheldon_uvc_streaming_intf, data, size, 5000);
498
499
500 kfree(data);
501
502 return (ret < 0) ? ret : 0;
503
504 }
505
506
507 /* 参考: uvc_v4l2_try_format ∕uvc_probe_video
508 * uvc_set_video_ctrl(video, probe, 1)
509 */
510 static int sheldon_uvc_set_streaming_params(struct sheldon_uvc_streaming_control *ctrl)
511 {
512 __u8 *data;
513 __u16 size;
514 int ret;
515 __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
516 unsigned int pipe;
517
518 size = uvc_version >= 0x0110 ? 34 : 26;
519 data = kzalloc(size, GFP_KERNEL);
520 if (data == NULL)
521 return -ENOMEM;
522
523 *(__le16 *)&data[0] = cpu_to_le16(ctrl->bmHint);
524 data[2] = ctrl->bFormatIndex;
525 data[3] = ctrl->bFrameIndex;
526 *(__le32 *)&data[4] = cpu_to_le32(ctrl->dwFrameInterval);
527 *(__le16 *)&data[8] = cpu_to_le16(ctrl->wKeyFrameRate);
528 *(__le16 *)&data[10] = cpu_to_le16(ctrl->wPFrameRate);
529 *(__le16 *)&data[12] = cpu_to_le16(ctrl->wCompQuality);
530 *(__le16 *)&data[14] = cpu_to_le16(ctrl->wCompWindowSize);
531 *(__le16 *)&data[16] = cpu_to_le16(ctrl->wDelay);
532 put_unaligned_le32(ctrl->dwMaxVideoFrameSize, &data[18]);
533 put_unaligned_le32(ctrl->dwMaxPayloadTransferSize, &data[22]);
534
535 if (size == 34) {
536 put_unaligned_le32(ctrl->dwClockFrequency, &data[26]);
537 data[30] = ctrl->bmFramingInfo;
538 data[31] = ctrl->bPreferedVersion;
539 data[32] = ctrl->bMinVersion;
540 data[33] = ctrl->bMaxVersion;
541 }
542
543 pipe = (SET_CUR & 0x80) ? usb_rcvctrlpipe(sheldon_uvc_udev, 0)
544 : usb_sndctrlpipe(sheldon_uvc_udev, 0);
545 type |= (SET_CUR & 0x80) ? USB_DIR_IN : USB_DIR_OUT;
546
547 ret = usb_control_msg(sheldon_uvc_udev, pipe, SET_CUR, type, VS_COMMIT_CONTROL << 8,
548 0 << 8 | sheldon_uvc_streaming_intf, data, size, 5000);
549
550 kfree(data);
551
552 return (ret < 0) ? ret : 0;
553
554 }
555
556
557 static void sheldon_uvc_uninit_urbs(void)
558 {
559 int i;
560 for (i = 0; i < sheldon_UVC_URBS; ++i) {
561 if (sheldon_uvc_queue.urb_buffer[i])
562 {
563 usb_buffer_free(sheldon_uvc_udev, sheldon_uvc_queue.urb_size, sheldon_uvc_queue.urb_buffer[i], sheldon_uvc_queue.urb_dma[i]);
564 sheldon_uvc_queue.urb_buffer[i] = NULL;
565 }
566
567 if (sheldon_uvc_queue.urb[i])
568 {
569 usb_free_urb(sheldon_uvc_queue.urb[i]);
570 sheldon_uvc_queue.urb[i] = NULL;
571 }
572 }
573 }
574
575
576 /* 参考: uvc_video_complete / uvc_video_decode_isoc */
577 static void sheldon_uvc_video_complete(struct urb *urb)
578 {
579 u8 *src;
580 u8 *dest;
581 int ret, i;
582 int len;
583 int maxlen;
584 int nbytes;
585 struct sheldon_uvc_buffer *buf;
586
587 switch (urb->status) {
588 case 0:
589 break;
590
591 default:
592 printk("Non-zero status (%d) in video "
593 "completion handler.\n", urb->status);
594 return;
595 }
596
597 /* 从irqqueue队列中取出第1个缓冲区 */
598 if (!list_empty(&sheldon_uvc_queue.irqqueue)) //如果队列不空
599 {
600 buf = list_first_entry(&sheldon_uvc_queue.irqqueue, struct sheldon_uvc_buffer, irq);
601
602
603 for (i = 0; i < urb->number_of_packets; ++i) {
604 if (urb->iso_frame_desc[i].status < 0) {
605 printk("USB isochronous frame "
606 "lost (%d).\n", urb->iso_frame_desc[i].status);
607 continue;
608 }
609
610 src = urb->transfer_buffer + urb->iso_frame_desc[i].offset; //源
611
612 dest = sheldon_uvc_queue.mem + buf->buf.m.offset + buf->buf.bytesused; //目的
613
614 len = urb->iso_frame_desc[i].actual_length; //整个数据长度
615 /* 判断数据是否有效 */
616 /* URB数据含义:
617 * data[0] : 头部长度
618 * data[1] : 错误状态
619 */
620 if (len < 2 || src[0] < 2 || src[0] > len)
621 continue;
622
623 /* Skip payloads marked with the error bit ("error frames"). */
624 if (src[1] & UVC_STREAM_ERR) {
625 printk("Dropping payload (error bit set).\n");
626 continue;
627 }
628
629 /* 除去头部后的数据长度 */
630 len -= src[0];
631
632 /* 缓冲区最多还能存多少数据 */
633 maxlen = buf->buf.length - buf->buf.bytesused;
634 nbytes = min(len, maxlen);
635
636 /* 复制数据 */
637 memcpy(dest, src + src[0], nbytes);
638 buf->buf.bytesused += nbytes;
639
640 /* 判断一帧数据是否已经全部接收到 */
641 if (len > maxlen) {
642 buf->state = VIDEOBUF_DONE;
643 }
644
645 /* Mark the buffer as done if the EOF marker is set. */
646 if (src[1] & UVC_STREAM_EOF && buf->buf.bytesused != 0) {
647 printk("Frame complete (EOF found).\n");
648 if (len == 0)
649 printk("EOF in empty payload.\n");
650 buf->state = VIDEOBUF_DONE;
651 }
652
653 }
654
655 /* 当接收完一帧数据,
656 * 从irqqueue中删除这个缓冲区
657 * 唤醒等待数据的进程
658 */
659 if (buf->state == VIDEOBUF_DONE ||
660 buf->state == VIDEOBUF_ERROR)
661 {
662 list_del(&buf->irq);
663 wake_up(&buf->wait);
664 }
665 }
666
667 /* 再次提交URB */
668 if ((ret = usb_submit_urb(urb, GFP_ATOMIC)) < 0) {
669 printk("Failed to resubmit video URB (%d).\n", ret);
670 }
671 }
672
673
674
675 /* 参考: uvc_init_video_isoc */
676 static int sheldon_uvc_alloc_init_urbs(void)
677 {
678 u16 psize;
679 u32 size;
680 int npackets;
681 int i;
682 int j;
683
684 struct urb *urb;
685
686 psize = wMaxPacketSize; /* 实时传输端点一次能传输的最大字节数 */
687 size = sheldon_uvc_params.dwMaxVideoFrameSize; /* 一帧数据的最大长度 */
688 npackets = DIV_ROUND_UP(size, psize);
689 if (npackets > 32)
690 npackets = 32;
691
692 size = sheldon_uvc_queue.urb_size = psize * npackets;
693
694 for (i = 0; i < sheldon_UVC_URBS; ++i) {
695 /* 1. 分配usb_buffers */
696
697 sheldon_uvc_queue.urb_buffer[i] = usb_buffer_alloc(
698 sheldon_uvc_udev, size,
699 GFP_KERNEL | __GFP_NOWARN, &sheldon_uvc_queue.urb_dma[i]); //sheldon_uvc_queue.urb_dma[i]存放分配的物理地址
700
701 /* 2. 分配urb */
702 sheldon_uvc_queue.urb[i] = usb_alloc_urb(npackets, GFP_KERNEL);
703
704 if (!sheldon_uvc_queue.urb_buffer[i] || !sheldon_uvc_queue.urb[i])
705 {
706 sheldon_uvc_uninit_urbs();
707 return -ENOMEM;
708 }
709
710 }
711
712 /* 3. 设置urb */
713 for (i = 0; i < sheldon_UVC_URBS; ++i) {
714 urb = sheldon_uvc_queue.urb[i];
715
716 urb->dev = sheldon_uvc_udev;
717 urb->context = NULL;
718 urb->pipe = usb_rcvisocpipe(sheldon_uvc_udev,sheldon_uvc_bEndpointAddress);
719 urb->transfer_flags = URB_ISO_ASAP | URB_NO_TRANSFER_DMA_MAP;
720 urb->interval = 1;
721 urb->transfer_buffer = sheldon_uvc_queue.urb_buffer[i]; //分配的urb buffer
722 urb->transfer_dma = sheldon_uvc_queue.urb_dma[i]; //分配的urb 物理地址
723 urb->complete = sheldon_uvc_video_complete; //收完数据的中断处理函数
724 urb->number_of_packets = npackets; //要传输的数据次数
725 urb->transfer_buffer_length = size; //总共的数据量
726
727 for (j = 0; j < npackets; ++j) {
728 urb->iso_frame_desc[j].offset = j * psize; //存放每次传输的数据
729 urb->iso_frame_desc[j].length = psize;
730 }
731
732 }
733
734 return 0;
735 }
736
737
738 /*打开视频流
739 * 参考: uvc_video_enable(video, 1):
740 * uvc_commit_video
741 * uvc_init_video
742 */
743 static int sheldonUV_vidioc_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
744 {
745 int ret;
746
747 /* 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)
748 * 参考: uvc_set_video_ctrl / uvc_get_video_ctrl
749 * 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
750 * 1.2 调用usb_control_msg发出数据包
751 */
752
753
754
755 /* a. 测试参数 */
756 ret = sheldon_uvc_try_streaming_params(&sheldon_uvc_params);
757 printk("sheldon_uvc_try_streaming_params ret = %d\n", ret);
758
759
760
761 /* b. 取出参数 */
762 ret = sheldon_uvc_get_streaming_params(&sheldon_uvc_params);
763 printk("sheldon_uvc_get_streaming_params ret = %d\n", ret);
764
765 /* c. 设置参数 */
766 ret = sheldon_uvc_set_streaming_params(&sheldon_uvc_params);
767 printk("sheldon_uvc_set_streaming_params ret = %d\n", ret);
768
769 sheldon_uvc_print_streaming_params(&sheldon_uvc_params);
770
771 /* d. 设置VideoStreaming Interface所使用的setting
772 * d.1 从sheldon_uvc_params确定带宽
773 * d.2 根据setting的endpoint能传输的wMaxPacketSize
774 * 找到能满足该带宽的setting
775 */
776 /* 手工确定:
777 * bandwidth = sheldon_uvc_params.dwMaxPayloadTransferSize = 64
778 * 观察lsusb -v -d 0x1e4e:的结果:
779 * wMaxPacketSize 0x0080 1x128 bytes
780 * bAlternateSetting 6
781 */
782 usb_set_interface(sheldon_uvc_udev, sheldon_uvc_streaming_intf, sheldon_uvc_streaming_bAlternateSetting);
783
784 /* 2. 分配设置URB */
785 ret = sheldon_uvc_alloc_init_urbs();
786 if (ret)
787 printk("sheldon_uvc_alloc_init_urbs err : ret = %d\n", ret);
788
789 /* 3. 提交URB以接收数据 */
790 for (i = 0; i < sheldon_UVC_URBS; ++i) {
791 if ((ret = usb_submit_urb(sheldon_uvc_queue.urb[i], GFP_KERNEL)) < 0) {
792 printk("Failed to submit URB %u (%d).\n", i, ret);
793 sheldon_uvc_uninit_urbs();
794 return ret;
795 }
796 }
797
798 return 0;
799 }
800
801
802 /*底层的硬件操作函数取出队列的缓存*/
803 static int sheldonUV_vidioc_dqbuf(struct file *file, void *priv, struct v4l2_buffer *v4l2_buf)
804 {
805 /* APP发现数据就绪后, 从mainqueue里取出这个buffer */
806
807 struct sheldon_uvc_buffer *buf;
808 int ret = 0;
809
810 if (list_empty(&sheldon_uvc_queue.mainqueue)) {
811 ret = -EINVAL;
812 goto done;
813 }
814
815 buf = list_first_entry(&sheldon_uvc_queue.mainqueue, struct sheldon_uvc_buffer, stream);
816
817 switch (buf->state) {
818 case VIDEOBUF_ERROR:
819 ret = -EIO;
820 case VIDEOBUF_DONE:
821 buf->state = VIDEOBUF_IDLE;
822 break;
823
824 case VIDEOBUF_IDLE:
825 case VIDEOBUF_QUEUED:
826 case VIDEOBUF_ACTIVE:
827 default:
828 ret = -EINVAL;
829 goto done;
830 }
831
832 list_del(&buf->stream);
833
834 done:
835 return ret;
836 }
837
838
839
840
841
842 /*
843 * A14 之前已经通过mmap映射了缓存, APP可以直接读数据
844 * A15 再次调用sheldonUV_vidioc_qbuf把缓存放入队列
845 * A16 poll...
846 */
847
848 /* A17 停止-关闭视频流
849 * 参考 : uvc_video_enable(video, 0)
850 */
851
852 static int sheldonUV_vidioc_streamoff(struct file *file, void *priv, enum v4l2_buf_type t)
853 {
854 struct urb *urb;
855 unsigned int i;
856
857 /* 1. kill URB */
858 for (i = 0; i < sheldon_UVC_URBS; ++i) {
859 if ((urb = sheldon_uvc_queue.urb[i]) == NULL)
860 continue;
861 usb_kill_urb(urb);
862 }
863
864 /* 2. free URB */
865 sheldon_uvc_uninit_urbs();
866
867 /* 3. 设置VideoStreaming Interface为setting 0 */
868 usb_set_interface(sheldon_uvc_udev, sheldon_uvc_streaming_intf, 0);
869
870 return 0;
871 }
872
873
874 /*[下面几个函数实现属性设置]*/
875
876 /*
877 *Extract the bit string specified by mapping->offset and mapping->size
878 * from the little-endian data stored at ‘data‘ and return the result as
879 * a signed 32bit integer. Sign extension will be performed if the mapping
880 * references a signed data type.
881 */
882 static __s32 sheldonUV_get_le_value(const __u8 *data)
883 {
884 int bits = 16;
885 int offset = 0;
886 __s32 value = 0;
887 __u8 mask;
888
889 data += offset / 8;
890 offset &= 7;
891 mask = ((1LL << bits) - 1) << offset;
892
893 for (; bits > 0; data++) {
894 __u8 byte = *data & mask;
895 value |= offset > 0 ? (byte >> offset) : (byte << (-offset));
896 bits -= 8 - (offset > 0 ? offset : 0);
897 offset -= 8;
898 mask = (1 << bits) - 1;
899 }
900
901 /* Sign-extend the value if needed. */
902 value |= -(value & (1 << (16 - 1)));
903
904 return value;
905 }
906
907 /* Set the bit string specified by mapping->offset and mapping->size
908 * in the little-endian data stored at ‘data‘ to the value ‘value‘.
909 */
910 static void sheldonUV_set_le_value(__s32 value, __u8 *data)
911 {
912 int bits = 16;
913 int offset = 0;
914 __u8 mask;
915
916 data += offset / 8;
917 offset &= 7;
918
919 for (; bits > 0; data++) {
920 mask = ((1LL << bits) - 1) << offset;
921 *data = (*data & ~mask) | ((value << offset) & mask);
922 value >>= offset ? offset : 8;
923 bits -= 8 - offset;
924 offset = 0;
925 }
926 }
927
928
929 /* 参考:uvc_query_v4l2_ctrl:调用VIDIOC_QUERYCTRL ioctl确定是否支持某个属性 */
930 int sheldonUV_vidioc_queryctrl (struct file *file, void *fh,
931 struct v4l2_queryctrl *ctrl)
932 {
933 __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
934 unsigned int pipe;
935 int ret;
936 u8 data[2];
937
938 if (ctrl->id != V4L2_CID_BRIGHTNESS)
939 return -EINVAL;
940
941 memset(ctrl, 0, sizeof *ctrl);
942 ctrl->id = V4L2_CID_BRIGHTNESS;
943 ctrl->type = V4L2_CTRL_TYPE_INTEGER;
944 strcpy(ctrl->name, "sheldonUV_BRIGHTNESS");
945 ctrl->flags = 0;
946
947 pipe = usb_rcvctrlpipe(sheldon_uvc_udev, 0);
948 type |= USB_DIR_IN;
949
950 /* 发起USB传输确定这些值 */
951 ret = usb_control_msg(sheldon_uvc_udev, pipe, GET_MIN, type, PU_BRIGHTNESS_CONTROL << 8,
952 ProcessingUnitID << 8 | sheldon_uvc_control_intf, data, 2, 5000);
953 if (ret != 2)
954 return -EIO;
955 ctrl->minimum = sheldonUV_get_le_value(data); /* Note signedness */
956
957
958 ret = usb_control_msg(sheldon_uvc_udev, pipe, GET_MAX, type, PU_BRIGHTNESS_CONTROL << 8,
959 ProcessingUnitID << 8 | sheldon_uvc_control_intf, data, 2, 5000);
960 if (ret != 2)
961 return -EIO;
962 ctrl->maximum = sheldonUV_get_le_value(data); /* Note signedness */
963
964 ret = usb_control_msg(sheldon_uvc_udev, pipe, GET_RES, type, PU_BRIGHTNESS_CONTROL << 8,
965 ProcessingUnitID << 8 | sheldon_uvc_control_intf, data, 2, 5000);
966 if (ret != 2)
967 return -EIO;
968 ctrl->step = sheldonUV_get_le_value(data); /* Note signedness */
969
970 ret = usb_control_msg(sheldon_uvc_udev, pipe, GET_DEF, type, PU_BRIGHTNESS_CONTROL << 8,
971 ProcessingUnitID << 8 | sheldon_uvc_control_intf, data, 2, 5000);
972 if (ret != 2)
973 return -EIO;
974 ctrl->default_value = sheldonUV_get_le_value(data); /* Note signedness */
975
976 printk("Brightness: min =%d, max = %d, step = %d, default = %d\n", ctrl->minimum, ctrl->maximum, ctrl->step, ctrl->default_value);
977
978 return 0;
979 }
980
981 /* 参考 : uvc_ctrl_get : 获得属性 */
982 int sheldonUV_vidioc_g_ctrl (struct file *file, void *fh,
983 struct v4l2_control *ctrl)
984 {
985 __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
986 unsigned int pipe;
987 int ret;
988 u8 data[2];
989
990 if (ctrl->id != V4L2_CID_BRIGHTNESS)
991 return -EINVAL;
992
993 pipe = usb_rcvctrlpipe(sheldon_uvc_udev, 0);
994 type |= USB_DIR_IN;
995
996 ret = usb_control_msg(sheldon_uvc_udev, pipe, GET_CUR, type, PU_BRIGHTNESS_CONTROL << 8,
997 ProcessingUnitID << 8 | sheldon_uvc_control_intf, data, 2, 5000);
998 if (ret != 2)
999 return -EIO;
1000 ctrl->value = sheldonUV_get_le_value(data); /* Note signedness */
1001
1002 return 0;
1003 }
1004
1005 /* 参考: uvc_ctrl_set/uvc_ctrl_commit : 设置属性*/
1006 int sheldonUV_vidioc_s_ctrl (struct file *file, void *fh,
1007 struct v4l2_control *ctrl)
1008 {
1009 __u8 type = USB_TYPE_CLASS | USB_RECIP_INTERFACE;
1010 unsigned int pipe;
1011 int ret;
1012 u8 data[2];
1013
1014 if (ctrl->id != V4L2_CID_BRIGHTNESS)
1015 return -EINVAL;
1016
1017 sheldonUV_set_le_value(ctrl->value, data);
1018
1019 pipe = usb_sndctrlpipe(sheldon_uvc_udev, 0);
1020 type |= USB_DIR_OUT;
1021
1022 ret = usb_control_msg(sheldon_uvc_udev, pipe, SET_CUR, type, PU_BRIGHTNESS_CONTROL << 8,
1023 ProcessingUnitID << 8 | sheldon_uvc_control_intf, data, 2, 5000);
1024 if (ret != 2)
1025 return -EIO;
1026
1027 return 0;
1028 }
1029
1030 static const struct v4l2_ioctl_ops sheldonUV_ioctl_ops = {
1031 // 表示它是一个摄像头设备
1032 .vidioc_querycap = sheldonUV_vidioc_querycap,
1033
1034 /* 用于列举、获得、测试、设置摄像头的数据的格式 */
1035 .vidioc_enum_fmt_vid_cap = sheldonUV_vidioc_enum_fmt_vid_cap,
1036 .vidioc_g_fmt_vid_cap = sheldonUV_vidioc_get_fmt_vid_cap,
1037 .vidioc_try_fmt_vid_cap = sheldonUV_vidioc_try_fmt_vid_cap,
1038 .vidioc_s_fmt_vid_cap = sheldonUV_vidioc_set_fmt_vid_cap,
1039
1040 /* 缓冲区操作: 申请/查询/放入队列/取出队列 */
1041 .vidioc_reqbufs = sheldonUV_vidioc_reqbufs,
1042 .vidioc_querybuf = sheldonUV_vidioc_querybuf,
1043 .vidioc_qbuf = sheldonUV_vidioc_qbuf,
1044 .vidioc_dqbuf = sheldonUV_vidioc_dqbuf,
1045
1046 /* 查询/获得/设置属性 */
1047 .vidioc_queryctrl = sheldonUV_vidioc_queryctrl,
1048 .vidioc_g_ctrl = sheldonUV_vidioc_g_ctrl,
1049 .vidioc_s_ctrl = sheldonUV_vidioc_s_ctrl,
1050
1051 // 启动/停止
1052 .vidioc_streamon = sheldonUV_vidioc_streamon,
1053 .vidioc_streamoff = sheldonUV_vidioc_streamoff,
1054 };
1055
1056
1057
1058 static int sheldonUV_open(struct file *file)
1059 {
1060 /* 队列操作2: 初始化 */
1061 /* videobuf_queue_vmalloc_init(&sheldonUV_vb_vidqueue, &sheldonUV_video_qops,
1062 NULL, &sheldonUV_queue_slock, V4L2_BUF_TYPE_VIDEO_CAPTURE, V4L2_FIELD_INTERLACED,
1063 sizeof(struct videobuf_buffer), NULL); // 倒数第2个参数是buffer的头部大小
1064
1065 sheldonUV_timer.expires = jiffies + 1;
1066 add_timer(&sheldonUV_timer);
1067 */
1068 return 0;
1069 }
1070
1071 static void sheldon_uvc_vm_open(struct vm_area_struct *vma)
1072 {
1073 struct sheldon_uvc_buffer *buffer = vma->vm_private_data;
1074 buffer->vma_use_count++;
1075 }
1076
1077 static void sheldon_uvc_vm_close(struct vm_area_struct *vma)
1078 {
1079 struct sheldon_uvc_buffer *buffer = vma->vm_private_data;
1080 buffer->vma_use_count--;
1081 }
1082
1083
1084
1085
1086 static struct vm_operations_struct sheldon_uvc_vm_ops = {
1087 .open = sheldon_uvc_vm_open,
1088 .close = sheldon_uvc_vm_close,
1089 };
1090
1091
1092 /*映射->应用程序空间,之后app可以直接操作这块
1093 * 参考: uvc_v4l2_mmap
1094 */
1095 static int sheldonUV_mmap(struct file *file, struct vm_area_struct *vma)
1096 {
1097 struct sheldon_uvc_buffer *buffer;
1098 struct page *page;
1099 unsigned long addr, start, size;
1100 unsigned int i;
1101 int ret = 0;
1102
1103 start = vma->vm_start;
1104 size = vma->vm_end - vma->vm_start;
1105
1106 /* 应用程序调用mmap函数时, 会传入offset参数
1107 * 根据这个offset找出指定的缓冲区
1108 */
1109 for (i = 0; i < sheldon_uvc_queue.count; ++i) {
1110 buffer = &sheldon_uvc_queue.buffer[i];
1111 if ((buffer->buf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
1112 break;
1113 }
1114
1115 if (i == sheldon_uvc_queue.count || size != sheldon_uvc_queue.buf_size) {
1116 ret = -EINVAL;
1117 goto done;
1118 }
1119
1120 /*
1121 * VM_IO marks the area as being an mmaped region for I/O to a
1122 * device. It also prevents the region from being core dumped.
1123 */
1124 vma->vm_flags |= VM_IO;
1125
1126 /* 根据虚拟地址找到缓冲区对应的page构体 */
1127 addr = (unsigned long)sheldon_uvc_queue.mem + buffer->buf.m.offset;
1128 while (size > 0) {
1129 page = vmalloc_to_page((void *)addr);
1130
1131 /* 把此page映射到APP对应的虚拟地址上面 */
1132 if ((ret = vm_insert_page(vma, start, page)) < 0)
1133 goto done;
1134
1135 start += PAGE_SIZE;
1136 addr += PAGE_SIZE;
1137 size -= PAGE_SIZE;
1138 }
1139
1140 vma->vm_ops = &sheldon_uvc_vm_ops;
1141 vma->vm_private_data = buffer;
1142 sheldon_uvc_vm_open(vma);
1143
1144 done:
1145 return ret;
1146 }
1147
1148
1149 /*APP 调用POLL/select确定缓存数据是否就绪*/
1150 static unsigned int sheldonUV_poll(struct file *file, struct poll_table_struct *wait)
1151 {
1152 struct sheldon_uvc_buffer *buf;
1153 unsigned int mask = 0;
1154
1155 /* 从mainqueuq中取出第1个缓冲区 */
1156
1157 /*判断它的状态, 如果未就绪, 休眠 */
1158
1159 if (list_empty(&sheldon_uvc_queue.mainqueue)) {
1160 mask |= POLLERR;
1161 goto done;
1162 }
1163
1164 buf = list_first_entry(&sheldon_uvc_queue.mainqueue, struct sheldon_uvc_buffer, stream);
1165
1166 poll_wait(file, &buf->wait, wait);
1167 if (buf->state == VIDEOBUF_DONE ||
1168 buf->state == VIDEOBUF_ERROR)
1169 mask |= POLLIN | POLLRDNORM;
1170
1171 done:
1172 return mask;
1173 }
1174
1175
1176 static int sheldonUV_close(struct file *file)
1177 {
1178 //del_timer(&sheldonUV_timer);
1179 //videobuf_stop(&sheldonUV_vb_vidqueue);
1180 //videobuf_mmap_free(&sheldonUV_vb_vidqueue);
1181
1182 return 0;
1183 }
1184
1185
1186 static const struct v4l2_file_operations sheldonUV_fops = {
1187 .owner = THIS_MODULE,
1188 .open = sheldonUV_open,
1189 .release = sheldonUV_close,
1190 .mmap = sheldonUV_mmap,
1191 .ioctl = video_ioctl2, /* V4L2 ioctl handler -> sheldonUV_ioctl_ops*/
1192 .poll = sheldonUV_poll,
1193 };
1194
1195
1196
1197
1198 static void sheldonUV_release(struct video_device *vdev)
1199 {
1200 }
1201
1202
1203 //probe处理函数，有匹配usb设备时调用
1204 static int sheldon_uvc_probe(struct usb_interface *intf, const struct usb_device_id *id)
1205 {
1206 static int cnt;
1207
1208 //根据interface结构体获得usb_devce结构体，其中包含了设备描述符
1209 struct usb_device *dev = interface_to_usbdev(intf);
1210 //此处需要定义一个描述符结构体
1211 struct usb_device_descriptor *descriptor = &dev->descriptor;
1212 //从usb_device结构体中获得配置描述符相关信息
1213 struct usb_host_config *host_config;
1214 struct usb_config_descriptor *config;
1215 //定义接口联合体描述符结构体,获得 IAD 接口
1216 struct usb_interface_assoc_descriptor *assoc_desc;
1217 //接口描述符
1218 struct usb_interface_descriptor *interface;
1219 //端点描述符
1220 struct usb_endpoint_descriptor *endpoint;
1221 //定义接口设置信息结构体
1222 //struct usb_interface_descriptor *idesc;
1223
1224
1225 int i, j ,k ,l ,m;
1226 unsigned char *buffer;
1227 int buflen;
1228
1229 int desc_len;
1230 //int desc_cnt;
1231
1232 sheldon_uvc_udev = dev;
1233
1234 printk("sheldn_uvc_probe : cnt = %d\n", cnt++);
1235
1236
1237 if (cnt == 1)
1238 {
1239 sheldon_uvc_control_intf = intf->cur_altsetting->desc.bInterfaceNumber;
1240 }
1241 else if(cnt == 2)
1242 {
1243 sheldon_uvc_streaming_intf = intf->cur_altsetting->desc.bInterfaceNumber;
1244 }
1245
1246 if (cnt == 2)
1247 {
1248 /*1.分配一个video_device结构体*/
1249 sheldon_uvc_vdev = video_device_alloc();
1250 /*2.设置*/
1251 /* 2.1 */
1252 sheldon_uvc_vdev->release = sheldonUV_release;
1253
1254 /* 2.2 */
1255 sheldon_uvc_vdev->fops = &sheldonUV_fops;
1256
1257 /* 2.3 */
1258 sheldon_uvc_vdev->ioctl_ops = &sheldonUV_ioctl_ops;
1259 /*3.注册*/
1260 video_register_device(sheldon_uvc_vdev ,VFL_TYPE_GRABBER, -1);
1261 }
1262
1263 return 0;
1264 }
1265
1266
1267
1268
1269 //disconnect函数，设备断开时调用
1270 static void sheldon_uvc_disconnect(struct usb_interface *intf)
1271 {
1272 static int cnt;
1273 printk("sheldon_uvc_disconnect : cnt = %d\n",cnt++);
1274
1275 if (cnt == 2)
1276 {
1277 video_unregister_device(sheldon_uvc_vdev);
1278 video_device_release(sheldon_uvc_vdev);
1279 }
1280
1281 }
1282
1283 //支持的设备类型信息
1284 static struct usb_device_id sheldon_uvc_ids[] = {
1285 /* Generic USB Video Class */
1286 { USB_INTERFACE_INFO(USB_CLASS_VIDEO, 1, 0) },/*1-视频控制接口*/
1287 { USB_INTERFACE_INFO(USB_CLASS_VIDEO, 2, 0) },/*2-视频流控制接口(被1包含)*/
1288 {}
1289 };
1290
1291
1292
1293 //1.分配usb_driver结构体
1294 //2.设置
1295
1296 static struct usb_driver sheldon_uvc_driver = {
1297 .name = "sheldon_UV",
1298 .probe = sheldon_uvc_probe,
1299 .disconnect = sheldon_uvc_disconnect,
1300 .id_table = sheldon_uvc_ids,
1301 };
1302
1303
1304 static int sheldon_uvc_init(void)
1305 {
1306 //3.注册
1307 printk("sheldon_uvc_init ~\n");
1308 usb_register(&sheldon_uvc_driver);
1309 return 0;
1310 }
1311
1312 static void sheldon_uvc_exit(void)
1313 {
1314 printk("sheldon_uvc_exit ~\n");
1315 usb_deregister(&sheldon_uvc_driver);
1316 }
1317
1318 module_init(sheldon_uvc_init);
1319 module_exit(sheldon_uvc_exit);
1320 MODULE_LICENSE("GPL");
时间： 2024-10-08 22:44:16