1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * uvc_video.c -- USB Video Class Gadget driver
4 *
5 * Copyright (C) 2009-2010
6 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/device.h>
11 #include <linux/errno.h>
12 #include <linux/usb/ch9.h>
13 #include <linux/usb/gadget.h>
14 #include <linux/usb/video.h>
15 #include <asm/unaligned.h>
16
17 #include <media/v4l2-dev.h>
18
19 #include "uvc.h"
20 #include "uvc_queue.h"
21 #include "uvc_video.h"
22
23 /* --------------------------------------------------------------------------
24 * Video codecs
25 */
26
27 static int
uvc_video_encode_header(struct uvc_video * video,struct uvc_buffer * buf,u8 * data,int len)28 uvc_video_encode_header(struct uvc_video *video, struct uvc_buffer *buf,
29 u8 *data, int len)
30 {
31 struct uvc_device *uvc = container_of(video, struct uvc_device, video);
32 struct usb_composite_dev *cdev = uvc->func.config->cdev;
33 struct timespec64 ts = ns_to_timespec64(buf->buf.vb2_buf.timestamp);
34 int pos = 2;
35
36 data[1] = UVC_STREAM_EOH | video->fid;
37
38 if (video->queue.buf_used == 0 && ts.tv_sec) {
39 /* dwClockFrequency is 48 MHz */
40 u32 pts = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48;
41
42 data[1] |= UVC_STREAM_PTS;
43 put_unaligned_le32(pts, &data[pos]);
44 pos += 4;
45 }
46
47 if (cdev->gadget->ops->get_frame) {
48 u32 sof, stc;
49
50 sof = usb_gadget_frame_number(cdev->gadget);
51 ktime_get_ts64(&ts);
52 stc = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48;
53
54 data[1] |= UVC_STREAM_SCR;
55 put_unaligned_le32(stc, &data[pos]);
56 put_unaligned_le16(sof, &data[pos+4]);
57 pos += 6;
58 }
59
60 data[0] = pos;
61
62 if (buf->bytesused - video->queue.buf_used <= len - pos)
63 data[1] |= UVC_STREAM_EOF;
64
65 return pos;
66 }
67
68 static int
uvc_video_encode_data(struct uvc_video * video,struct uvc_buffer * buf,u8 * data,int len)69 uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf,
70 u8 *data, int len)
71 {
72 struct uvc_video_queue *queue = &video->queue;
73 unsigned int nbytes;
74 void *mem;
75
76 /* Copy video data to the USB buffer. */
77 mem = buf->mem + queue->buf_used;
78 nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used);
79
80 memcpy(data, mem, nbytes);
81 queue->buf_used += nbytes;
82
83 return nbytes;
84 }
85
86 static void
uvc_video_encode_bulk(struct usb_request * req,struct uvc_video * video,struct uvc_buffer * buf)87 uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video,
88 struct uvc_buffer *buf)
89 {
90 void *mem = req->buf;
91 int len = video->req_size;
92 int ret;
93
94 /* Add a header at the beginning of the payload. */
95 if (video->payload_size == 0) {
96 ret = uvc_video_encode_header(video, buf, mem, len);
97 video->payload_size += ret;
98 mem += ret;
99 len -= ret;
100 }
101
102 /* Process video data. */
103 len = min((int)(video->max_payload_size - video->payload_size), len);
104 ret = uvc_video_encode_data(video, buf, mem, len);
105
106 video->payload_size += ret;
107 len -= ret;
108
109 req->length = video->req_size - len;
110 req->zero = video->payload_size == video->max_payload_size;
111
112 if (buf->bytesused == video->queue.buf_used) {
113 video->queue.buf_used = 0;
114 buf->state = UVC_BUF_STATE_DONE;
115 list_del(&buf->queue);
116 uvcg_complete_buffer(&video->queue, buf);
117 video->fid ^= UVC_STREAM_FID;
118
119 video->payload_size = 0;
120 }
121
122 if (video->payload_size == video->max_payload_size ||
123 buf->bytesused == video->queue.buf_used)
124 video->payload_size = 0;
125 }
126
127 static void
uvc_video_encode_isoc_sg(struct usb_request * req,struct uvc_video * video,struct uvc_buffer * buf)128 uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
129 struct uvc_buffer *buf)
130 {
131 unsigned int pending = buf->bytesused - video->queue.buf_used;
132 struct uvc_request *ureq = req->context;
133 struct scatterlist *sg, *iter;
134 unsigned int len = video->req_size;
135 unsigned int sg_left, part = 0;
136 unsigned int i;
137 int header_len;
138
139 sg = ureq->sgt.sgl;
140 sg_init_table(sg, ureq->sgt.nents);
141
142 /* Init the header. */
143 header_len = uvc_video_encode_header(video, buf, ureq->header,
144 video->req_size);
145 sg_set_buf(sg, ureq->header, header_len);
146 len -= header_len;
147
148 if (pending <= len)
149 len = pending;
150
151 req->length = (len == pending) ?
152 len + header_len : video->req_size;
153
154 /* Init the pending sgs with payload */
155 sg = sg_next(sg);
156
157 for_each_sg(sg, iter, ureq->sgt.nents - 1, i) {
158 if (!len || !buf->sg || !sg_dma_len(buf->sg))
159 break;
160
161 sg_left = sg_dma_len(buf->sg) - buf->offset;
162 part = min_t(unsigned int, len, sg_left);
163
164 sg_set_page(iter, sg_page(buf->sg), part, buf->offset);
165
166 if (part == sg_left) {
167 buf->offset = 0;
168 buf->sg = sg_next(buf->sg);
169 } else {
170 buf->offset += part;
171 }
172 len -= part;
173 }
174
175 /* Assign the video data with header. */
176 req->buf = NULL;
177 req->sg = ureq->sgt.sgl;
178 req->num_sgs = i + 1;
179
180 req->length -= len;
181 video->queue.buf_used += req->length - header_len;
182
183 if (buf->bytesused == video->queue.buf_used || !buf->sg) {
184 video->queue.buf_used = 0;
185 buf->state = UVC_BUF_STATE_DONE;
186 buf->offset = 0;
187 list_del(&buf->queue);
188 video->fid ^= UVC_STREAM_FID;
189 ureq->last_buf = buf;
190 }
191 }
192
193 static void
uvc_video_encode_isoc(struct usb_request * req,struct uvc_video * video,struct uvc_buffer * buf)194 uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
195 struct uvc_buffer *buf)
196 {
197 void *mem = req->buf;
198 int len = video->req_size;
199 int ret;
200
201 /* Add the header. */
202 ret = uvc_video_encode_header(video, buf, mem, len);
203 mem += ret;
204 len -= ret;
205
206 /* Process video data. */
207 ret = uvc_video_encode_data(video, buf, mem, len);
208 len -= ret;
209
210 req->length = video->req_size - len;
211
212 if (buf->bytesused == video->queue.buf_used) {
213 video->queue.buf_used = 0;
214 buf->state = UVC_BUF_STATE_DONE;
215 list_del(&buf->queue);
216 uvcg_complete_buffer(&video->queue, buf);
217 video->fid ^= UVC_STREAM_FID;
218 }
219 }
220
221 /* --------------------------------------------------------------------------
222 * Request handling
223 */
224
uvcg_video_ep_queue(struct uvc_video * video,struct usb_request * req)225 static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
226 {
227 int ret;
228
229 ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
230 if (ret < 0) {
231 uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
232 ret);
233
234 /* If the endpoint is disabled the descriptor may be NULL. */
235 if (video->ep->desc) {
236 /* Isochronous endpoints can't be halted. */
237 if (usb_endpoint_xfer_bulk(video->ep->desc))
238 usb_ep_set_halt(video->ep);
239 }
240 }
241
242 return ret;
243 }
244
245 static void
uvc_video_complete(struct usb_ep * ep,struct usb_request * req)246 uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
247 {
248 struct uvc_request *ureq = req->context;
249 struct uvc_video *video = ureq->video;
250 struct uvc_video_queue *queue = &video->queue;
251 struct uvc_device *uvc = video->uvc;
252 unsigned long flags;
253
254 switch (req->status) {
255 case 0:
256 break;
257
258 case -ESHUTDOWN: /* disconnect from host. */
259 uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");
260 uvcg_queue_cancel(queue, 1);
261 break;
262
263 default:
264 uvcg_warn(&video->uvc->func,
265 "VS request completed with status %d.\n",
266 req->status);
267 uvcg_queue_cancel(queue, 0);
268 }
269
270 if (ureq->last_buf) {
271 uvcg_complete_buffer(&video->queue, ureq->last_buf);
272 ureq->last_buf = NULL;
273 }
274
275 spin_lock_irqsave(&video->req_lock, flags);
276 list_add_tail(&req->list, &video->req_free);
277 spin_unlock_irqrestore(&video->req_lock, flags);
278
279 if (uvc->state == UVC_STATE_STREAMING)
280 schedule_work(&video->pump);
281 }
282
283 static int
uvc_video_free_requests(struct uvc_video * video)284 uvc_video_free_requests(struct uvc_video *video)
285 {
286 unsigned int i;
287
288 if (video->ureq) {
289 for (i = 0; i < video->uvc_num_requests; ++i) {
290 sg_free_table(&video->ureq[i].sgt);
291
292 if (video->ureq[i].req) {
293 usb_ep_free_request(video->ep, video->ureq[i].req);
294 video->ureq[i].req = NULL;
295 }
296
297 if (video->ureq[i].req_buffer) {
298 kfree(video->ureq[i].req_buffer);
299 video->ureq[i].req_buffer = NULL;
300 }
301 }
302
303 kfree(video->ureq);
304 video->ureq = NULL;
305 }
306
307 INIT_LIST_HEAD(&video->req_free);
308 video->req_size = 0;
309 return 0;
310 }
311
312 static int
uvc_video_alloc_requests(struct uvc_video * video)313 uvc_video_alloc_requests(struct uvc_video *video)
314 {
315 unsigned int req_size;
316 unsigned int i;
317 int ret = -ENOMEM;
318
319 BUG_ON(video->req_size);
320
321 req_size = video->ep->maxpacket
322 * max_t(unsigned int, video->ep->maxburst, 1)
323 * (video->ep->mult);
324
325 video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL);
326 if (video->ureq == NULL)
327 return -ENOMEM;
328
329 for (i = 0; i < video->uvc_num_requests; ++i) {
330 video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL);
331 if (video->ureq[i].req_buffer == NULL)
332 goto error;
333
334 video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL);
335 if (video->ureq[i].req == NULL)
336 goto error;
337
338 video->ureq[i].req->buf = video->ureq[i].req_buffer;
339 video->ureq[i].req->length = 0;
340 video->ureq[i].req->complete = uvc_video_complete;
341 video->ureq[i].req->context = &video->ureq[i];
342 video->ureq[i].video = video;
343 video->ureq[i].last_buf = NULL;
344
345 list_add_tail(&video->ureq[i].req->list, &video->req_free);
346 /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */
347 sg_alloc_table(&video->ureq[i].sgt,
348 DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN,
349 PAGE_SIZE) + 2, GFP_KERNEL);
350 }
351
352 video->req_size = req_size;
353
354 return 0;
355
356 error:
357 uvc_video_free_requests(video);
358 return ret;
359 }
360
361 /* --------------------------------------------------------------------------
362 * Video streaming
363 */
364
365 /*
366 * uvcg_video_pump - Pump video data into the USB requests
367 *
368 * This function fills the available USB requests (listed in req_free) with
369 * video data from the queued buffers.
370 */
uvcg_video_pump(struct work_struct * work)371 static void uvcg_video_pump(struct work_struct *work)
372 {
373 struct uvc_video *video = container_of(work, struct uvc_video, pump);
374 struct uvc_video_queue *queue = &video->queue;
375 struct usb_request *req = NULL;
376 struct uvc_buffer *buf;
377 unsigned long flags;
378 int ret;
379
380 while (video->ep->enabled) {
381 /*
382 * Retrieve the first available USB request, protected by the
383 * request lock.
384 */
385 spin_lock_irqsave(&video->req_lock, flags);
386 if (list_empty(&video->req_free)) {
387 spin_unlock_irqrestore(&video->req_lock, flags);
388 return;
389 }
390 req = list_first_entry(&video->req_free, struct usb_request,
391 list);
392 list_del(&req->list);
393 spin_unlock_irqrestore(&video->req_lock, flags);
394
395 /*
396 * Retrieve the first available video buffer and fill the
397 * request, protected by the video queue irqlock.
398 */
399 spin_lock_irqsave(&queue->irqlock, flags);
400 buf = uvcg_queue_head(queue);
401 if (buf == NULL) {
402 spin_unlock_irqrestore(&queue->irqlock, flags);
403 break;
404 }
405
406 video->encode(req, video, buf);
407
408 /*
409 * With usb3 we have more requests. This will decrease the
410 * interrupt load to a quarter but also catches the corner
411 * cases, which needs to be handled.
412 */
413 if (list_empty(&video->req_free) ||
414 buf->state == UVC_BUF_STATE_DONE ||
415 !(video->req_int_count %
416 DIV_ROUND_UP(video->uvc_num_requests, 4))) {
417 video->req_int_count = 0;
418 req->no_interrupt = 0;
419 } else {
420 req->no_interrupt = 1;
421 }
422
423 /* Queue the USB request */
424 ret = uvcg_video_ep_queue(video, req);
425 spin_unlock_irqrestore(&queue->irqlock, flags);
426
427 if (ret < 0) {
428 uvcg_queue_cancel(queue, 0);
429 break;
430 }
431
432 /* Endpoint now owns the request */
433 req = NULL;
434 video->req_int_count++;
435 }
436
437 if (!req)
438 return;
439
440 spin_lock_irqsave(&video->req_lock, flags);
441 list_add_tail(&req->list, &video->req_free);
442 spin_unlock_irqrestore(&video->req_lock, flags);
443 return;
444 }
445
446 /*
447 * Enable or disable the video stream.
448 */
uvcg_video_enable(struct uvc_video * video,int enable)449 int uvcg_video_enable(struct uvc_video *video, int enable)
450 {
451 unsigned int i;
452 int ret;
453
454 if (video->ep == NULL) {
455 uvcg_info(&video->uvc->func,
456 "Video enable failed, device is uninitialized.\n");
457 return -ENODEV;
458 }
459
460 if (!enable) {
461 cancel_work_sync(&video->pump);
462 uvcg_queue_cancel(&video->queue, 0);
463
464 for (i = 0; i < video->uvc_num_requests; ++i)
465 if (video->ureq && video->ureq[i].req)
466 usb_ep_dequeue(video->ep, video->ureq[i].req);
467
468 uvc_video_free_requests(video);
469 uvcg_queue_enable(&video->queue, 0);
470 return 0;
471 }
472
473 if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0)
474 return ret;
475
476 if ((ret = uvc_video_alloc_requests(video)) < 0)
477 return ret;
478
479 if (video->max_payload_size) {
480 video->encode = uvc_video_encode_bulk;
481 video->payload_size = 0;
482 } else
483 video->encode = video->queue.use_sg ?
484 uvc_video_encode_isoc_sg : uvc_video_encode_isoc;
485
486 video->req_int_count = 0;
487
488 schedule_work(&video->pump);
489
490 return ret;
491 }
492
493 /*
494 * Initialize the UVC video stream.
495 */
uvcg_video_init(struct uvc_video * video,struct uvc_device * uvc)496 int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
497 {
498 INIT_LIST_HEAD(&video->req_free);
499 spin_lock_init(&video->req_lock);
500 INIT_WORK(&video->pump, uvcg_video_pump);
501
502 video->uvc = uvc;
503 video->fcc = V4L2_PIX_FMT_YUYV;
504 video->bpp = 16;
505 video->width = 320;
506 video->height = 240;
507 video->imagesize = 320 * 240 * 2;
508
509 /* Initialize the video buffers queue. */
510 uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent,
511 V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex);
512 return 0;
513 }
514
515