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 uvcg_queue_next_buffer(&video->queue, buf);
116 video->fid ^= UVC_STREAM_FID;
117
118 video->payload_size = 0;
119 }
120
121 if (video->payload_size == video->max_payload_size ||
122 buf->bytesused == video->queue.buf_used)
123 video->payload_size = 0;
124 }
125
126 static void
uvc_video_encode_isoc_sg(struct usb_request * req,struct uvc_video * video,struct uvc_buffer * buf)127 uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video,
128 struct uvc_buffer *buf)
129 {
130 unsigned int pending = buf->bytesused - video->queue.buf_used;
131 struct uvc_request *ureq = req->context;
132 struct scatterlist *sg, *iter;
133 unsigned int len = video->req_size;
134 unsigned int sg_left, part = 0;
135 unsigned int i;
136 int header_len;
137
138 sg = ureq->sgt.sgl;
139 sg_init_table(sg, ureq->sgt.nents);
140
141 /* Init the header. */
142 header_len = uvc_video_encode_header(video, buf, ureq->header,
143 video->req_size);
144 sg_set_buf(sg, ureq->header, header_len);
145 len -= header_len;
146
147 if (pending <= len)
148 len = pending;
149
150 req->length = (len == pending) ?
151 len + header_len : video->req_size;
152
153 /* Init the pending sgs with payload */
154 sg = sg_next(sg);
155
156 for_each_sg(sg, iter, ureq->sgt.nents - 1, i) {
157 if (!len || !buf->sg)
158 break;
159
160 sg_left = sg_dma_len(buf->sg) - buf->offset;
161 part = min_t(unsigned int, len, sg_left);
162
163 sg_set_page(iter, sg_page(buf->sg), part, buf->offset);
164
165 if (part == sg_left) {
166 buf->offset = 0;
167 buf->sg = sg_next(buf->sg);
168 } else {
169 buf->offset += part;
170 }
171 len -= part;
172 }
173
174 /* Assign the video data with header. */
175 req->buf = NULL;
176 req->sg = ureq->sgt.sgl;
177 req->num_sgs = i + 1;
178
179 req->length -= len;
180 video->queue.buf_used += req->length - header_len;
181
182 if (buf->bytesused == video->queue.buf_used || !buf->sg) {
183 video->queue.buf_used = 0;
184 buf->state = UVC_BUF_STATE_DONE;
185 buf->offset = 0;
186 uvcg_queue_next_buffer(&video->queue, buf);
187 video->fid ^= UVC_STREAM_FID;
188 }
189 }
190
191 static void
uvc_video_encode_isoc(struct usb_request * req,struct uvc_video * video,struct uvc_buffer * buf)192 uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video,
193 struct uvc_buffer *buf)
194 {
195 void *mem = req->buf;
196 int len = video->req_size;
197 int ret;
198
199 /* Add the header. */
200 ret = uvc_video_encode_header(video, buf, mem, len);
201 mem += ret;
202 len -= ret;
203
204 /* Process video data. */
205 ret = uvc_video_encode_data(video, buf, mem, len);
206 len -= ret;
207
208 req->length = video->req_size - len;
209
210 if (buf->bytesused == video->queue.buf_used) {
211 video->queue.buf_used = 0;
212 buf->state = UVC_BUF_STATE_DONE;
213 uvcg_queue_next_buffer(&video->queue, buf);
214 video->fid ^= UVC_STREAM_FID;
215 }
216 }
217
218 /* --------------------------------------------------------------------------
219 * Request handling
220 */
221
uvcg_video_ep_queue(struct uvc_video * video,struct usb_request * req)222 static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req)
223 {
224 int ret;
225
226 ret = usb_ep_queue(video->ep, req, GFP_ATOMIC);
227 if (ret < 0) {
228 uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n",
229 ret);
230
231 /* If the endpoint is disabled the descriptor may be NULL. */
232 if (video->ep->desc) {
233 /* Isochronous endpoints can't be halted. */
234 if (usb_endpoint_xfer_bulk(video->ep->desc))
235 usb_ep_set_halt(video->ep);
236 }
237 }
238
239 return ret;
240 }
241
242 static void
uvc_video_complete(struct usb_ep * ep,struct usb_request * req)243 uvc_video_complete(struct usb_ep *ep, struct usb_request *req)
244 {
245 struct uvc_request *ureq = req->context;
246 struct uvc_video *video = ureq->video;
247 struct uvc_video_queue *queue = &video->queue;
248 struct uvc_device *uvc = video->uvc;
249 unsigned long flags;
250
251 switch (req->status) {
252 case 0:
253 break;
254
255 case -ESHUTDOWN: /* disconnect from host. */
256 uvcg_dbg(&video->uvc->func, "VS request cancelled.\n");
257 uvcg_queue_cancel(queue, 1);
258 break;
259
260 default:
261 uvcg_info(&video->uvc->func,
262 "VS request completed with status %d.\n",
263 req->status);
264 uvcg_queue_cancel(queue, 0);
265 }
266
267 spin_lock_irqsave(&video->req_lock, flags);
268 list_add_tail(&req->list, &video->req_free);
269 spin_unlock_irqrestore(&video->req_lock, flags);
270
271 if (uvc->state == UVC_STATE_STREAMING)
272 schedule_work(&video->pump);
273 }
274
275 static int
uvc_video_free_requests(struct uvc_video * video)276 uvc_video_free_requests(struct uvc_video *video)
277 {
278 unsigned int i;
279
280 if (video->ureq) {
281 for (i = 0; i < video->uvc_num_requests; ++i) {
282 sg_free_table(&video->ureq[i].sgt);
283
284 if (video->ureq[i].req) {
285 usb_ep_free_request(video->ep, video->ureq[i].req);
286 video->ureq[i].req = NULL;
287 }
288
289 if (video->ureq[i].req_buffer) {
290 kfree(video->ureq[i].req_buffer);
291 video->ureq[i].req_buffer = NULL;
292 }
293 }
294
295 kfree(video->ureq);
296 video->ureq = NULL;
297 }
298
299 INIT_LIST_HEAD(&video->req_free);
300 video->req_size = 0;
301 return 0;
302 }
303
304 static int
uvc_video_alloc_requests(struct uvc_video * video)305 uvc_video_alloc_requests(struct uvc_video *video)
306 {
307 unsigned int req_size;
308 unsigned int i;
309 int ret = -ENOMEM;
310
311 BUG_ON(video->req_size);
312
313 req_size = video->ep->maxpacket
314 * max_t(unsigned int, video->ep->maxburst, 1)
315 * (video->ep->mult);
316
317 video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL);
318 if (video->ureq == NULL)
319 return -ENOMEM;
320
321 for (i = 0; i < video->uvc_num_requests; ++i) {
322 video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL);
323 if (video->ureq[i].req_buffer == NULL)
324 goto error;
325
326 video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL);
327 if (video->ureq[i].req == NULL)
328 goto error;
329
330 video->ureq[i].req->buf = video->ureq[i].req_buffer;
331 video->ureq[i].req->length = 0;
332 video->ureq[i].req->complete = uvc_video_complete;
333 video->ureq[i].req->context = &video->ureq[i];
334 video->ureq[i].video = video;
335
336 list_add_tail(&video->ureq[i].req->list, &video->req_free);
337 /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */
338 sg_alloc_table(&video->ureq[i].sgt,
339 DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN,
340 PAGE_SIZE) + 2, GFP_KERNEL);
341 }
342
343 video->req_size = req_size;
344
345 return 0;
346
347 error:
348 uvc_video_free_requests(video);
349 return ret;
350 }
351
352 /* --------------------------------------------------------------------------
353 * Video streaming
354 */
355
356 /*
357 * uvcg_video_pump - Pump video data into the USB requests
358 *
359 * This function fills the available USB requests (listed in req_free) with
360 * video data from the queued buffers.
361 */
uvcg_video_pump(struct work_struct * work)362 static void uvcg_video_pump(struct work_struct *work)
363 {
364 struct uvc_video *video = container_of(work, struct uvc_video, pump);
365 struct uvc_video_queue *queue = &video->queue;
366 struct usb_request *req = NULL;
367 struct uvc_buffer *buf;
368 unsigned long flags;
369 int ret;
370
371 while (video->ep->enabled) {
372 /* Retrieve the first available USB request, protected by the
373 * request lock.
374 */
375 spin_lock_irqsave(&video->req_lock, flags);
376 if (list_empty(&video->req_free)) {
377 spin_unlock_irqrestore(&video->req_lock, flags);
378 return;
379 }
380 req = list_first_entry(&video->req_free, struct usb_request,
381 list);
382 list_del(&req->list);
383 spin_unlock_irqrestore(&video->req_lock, flags);
384
385 /* Retrieve the first available video buffer and fill the
386 * request, protected by the video queue irqlock.
387 */
388 spin_lock_irqsave(&queue->irqlock, flags);
389 buf = uvcg_queue_head(queue);
390 if (buf == NULL) {
391 spin_unlock_irqrestore(&queue->irqlock, flags);
392 break;
393 }
394
395 video->encode(req, video, buf);
396
397 /* With usb3 we have more requests. This will decrease the
398 * interrupt load to a quarter but also catches the corner
399 * cases, which needs to be handled */
400 if (list_empty(&video->req_free) ||
401 buf->state == UVC_BUF_STATE_DONE ||
402 !(video->req_int_count %
403 DIV_ROUND_UP(video->uvc_num_requests, 4))) {
404 video->req_int_count = 0;
405 req->no_interrupt = 0;
406 } else {
407 req->no_interrupt = 1;
408 }
409
410 /* Queue the USB request */
411 ret = uvcg_video_ep_queue(video, req);
412 spin_unlock_irqrestore(&queue->irqlock, flags);
413
414 if (ret < 0) {
415 uvcg_queue_cancel(queue, 0);
416 break;
417 }
418 video->req_int_count++;
419 }
420
421 if (!req)
422 return;
423
424 spin_lock_irqsave(&video->req_lock, flags);
425 list_add_tail(&req->list, &video->req_free);
426 spin_unlock_irqrestore(&video->req_lock, flags);
427 return;
428 }
429
430 /*
431 * Enable or disable the video stream.
432 */
uvcg_video_enable(struct uvc_video * video,int enable)433 int uvcg_video_enable(struct uvc_video *video, int enable)
434 {
435 unsigned int i;
436 int ret;
437
438 if (video->ep == NULL) {
439 uvcg_info(&video->uvc->func,
440 "Video enable failed, device is uninitialized.\n");
441 return -ENODEV;
442 }
443
444 if (!enable) {
445 cancel_work_sync(&video->pump);
446 uvcg_queue_cancel(&video->queue, 0);
447
448 for (i = 0; i < video->uvc_num_requests; ++i)
449 if (video->ureq && video->ureq[i].req)
450 usb_ep_dequeue(video->ep, video->ureq[i].req);
451
452 uvc_video_free_requests(video);
453 uvcg_queue_enable(&video->queue, 0);
454 return 0;
455 }
456
457 if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0)
458 return ret;
459
460 if ((ret = uvc_video_alloc_requests(video)) < 0)
461 return ret;
462
463 if (video->max_payload_size) {
464 video->encode = uvc_video_encode_bulk;
465 video->payload_size = 0;
466 } else
467 video->encode = video->queue.use_sg ?
468 uvc_video_encode_isoc_sg : uvc_video_encode_isoc;
469
470 video->req_int_count = 0;
471
472 schedule_work(&video->pump);
473
474 return ret;
475 }
476
477 /*
478 * Initialize the UVC video stream.
479 */
uvcg_video_init(struct uvc_video * video,struct uvc_device * uvc)480 int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc)
481 {
482 INIT_LIST_HEAD(&video->req_free);
483 spin_lock_init(&video->req_lock);
484 INIT_WORK(&video->pump, uvcg_video_pump);
485
486 video->uvc = uvc;
487 video->fcc = V4L2_PIX_FMT_YUYV;
488 video->bpp = 16;
489 video->width = 320;
490 video->height = 240;
491 video->imagesize = 320 * 240 * 2;
492
493 /* Initialize the video buffers queue. */
494 uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent,
495 V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex);
496 return 0;
497 }
498
499