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