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 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.flags & UVC_QUEUE_DROP_INCOMPLETE) 39 data[1] |= UVC_STREAM_ERR; 40 41 if (video->queue.buf_used == 0 && ts.tv_sec) { 42 /* dwClockFrequency is 48 MHz */ 43 u32 pts = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48; 44 45 data[1] |= UVC_STREAM_PTS; 46 put_unaligned_le32(pts, &data[pos]); 47 pos += 4; 48 } 49 50 if (cdev->gadget->ops->get_frame) { 51 u32 sof, stc; 52 53 sof = usb_gadget_frame_number(cdev->gadget); 54 ktime_get_ts64(&ts); 55 stc = ((u64)ts.tv_sec * USEC_PER_SEC + ts.tv_nsec / NSEC_PER_USEC) * 48; 56 57 data[1] |= UVC_STREAM_SCR; 58 put_unaligned_le32(stc, &data[pos]); 59 put_unaligned_le16(sof, &data[pos+4]); 60 pos += 6; 61 } 62 63 data[0] = pos; 64 65 if (buf->bytesused - video->queue.buf_used <= len - pos) 66 data[1] |= UVC_STREAM_EOF; 67 68 return pos; 69 } 70 71 static int 72 uvc_video_encode_data(struct uvc_video *video, struct uvc_buffer *buf, 73 u8 *data, int len) 74 { 75 struct uvc_video_queue *queue = &video->queue; 76 unsigned int nbytes; 77 void *mem; 78 79 /* Copy video data to the USB buffer. */ 80 mem = buf->mem + queue->buf_used; 81 nbytes = min((unsigned int)len, buf->bytesused - queue->buf_used); 82 83 memcpy(data, mem, nbytes); 84 queue->buf_used += nbytes; 85 86 return nbytes; 87 } 88 89 static void 90 uvc_video_encode_bulk(struct usb_request *req, struct uvc_video *video, 91 struct uvc_buffer *buf) 92 { 93 void *mem = req->buf; 94 struct uvc_request *ureq = req->context; 95 int len = video->req_size; 96 int ret; 97 98 /* Add a header at the beginning of the payload. */ 99 if (video->payload_size == 0) { 100 ret = uvc_video_encode_header(video, buf, mem, len); 101 video->payload_size += ret; 102 mem += ret; 103 len -= ret; 104 } 105 106 /* Process video data. */ 107 len = min((int)(video->max_payload_size - video->payload_size), len); 108 ret = uvc_video_encode_data(video, buf, mem, len); 109 110 video->payload_size += ret; 111 len -= ret; 112 113 req->length = video->req_size - len; 114 req->zero = video->payload_size == video->max_payload_size; 115 116 if (buf->bytesused == video->queue.buf_used) { 117 video->queue.buf_used = 0; 118 buf->state = UVC_BUF_STATE_DONE; 119 list_del(&buf->queue); 120 video->fid ^= UVC_STREAM_FID; 121 ureq->last_buf = buf; 122 123 video->payload_size = 0; 124 } 125 126 if (video->payload_size == video->max_payload_size || 127 video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE || 128 buf->bytesused == video->queue.buf_used) 129 video->payload_size = 0; 130 } 131 132 static void 133 uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video, 134 struct uvc_buffer *buf) 135 { 136 unsigned int pending = buf->bytesused - video->queue.buf_used; 137 struct uvc_request *ureq = req->context; 138 struct scatterlist *sg, *iter; 139 unsigned int len = video->req_size; 140 unsigned int sg_left, part = 0; 141 unsigned int i; 142 int header_len; 143 144 sg = ureq->sgt.sgl; 145 sg_init_table(sg, ureq->sgt.nents); 146 147 /* Init the header. */ 148 header_len = uvc_video_encode_header(video, buf, ureq->header, 149 video->req_size); 150 sg_set_buf(sg, ureq->header, header_len); 151 len -= header_len; 152 153 if (pending <= len) 154 len = pending; 155 156 req->length = (len == pending) ? 157 len + header_len : video->req_size; 158 159 /* Init the pending sgs with payload */ 160 sg = sg_next(sg); 161 162 for_each_sg(sg, iter, ureq->sgt.nents - 1, i) { 163 if (!len || !buf->sg || !buf->sg->length) 164 break; 165 166 sg_left = buf->sg->length - buf->offset; 167 part = min_t(unsigned int, len, sg_left); 168 169 sg_set_page(iter, sg_page(buf->sg), part, buf->offset); 170 171 if (part == sg_left) { 172 buf->offset = 0; 173 buf->sg = sg_next(buf->sg); 174 } else { 175 buf->offset += part; 176 } 177 len -= part; 178 } 179 180 /* Assign the video data with header. */ 181 req->buf = NULL; 182 req->sg = ureq->sgt.sgl; 183 req->num_sgs = i + 1; 184 185 req->length -= len; 186 video->queue.buf_used += req->length - header_len; 187 188 if (buf->bytesused == video->queue.buf_used || !buf->sg || 189 video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) { 190 video->queue.buf_used = 0; 191 buf->state = UVC_BUF_STATE_DONE; 192 buf->offset = 0; 193 list_del(&buf->queue); 194 video->fid ^= UVC_STREAM_FID; 195 ureq->last_buf = buf; 196 } 197 } 198 199 static void 200 uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, 201 struct uvc_buffer *buf) 202 { 203 void *mem = req->buf; 204 struct uvc_request *ureq = req->context; 205 int len = video->req_size; 206 int ret; 207 208 /* Add the header. */ 209 ret = uvc_video_encode_header(video, buf, mem, len); 210 mem += ret; 211 len -= ret; 212 213 /* Process video data. */ 214 ret = uvc_video_encode_data(video, buf, mem, len); 215 len -= ret; 216 217 req->length = video->req_size - len; 218 219 if (buf->bytesused == video->queue.buf_used || 220 video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) { 221 video->queue.buf_used = 0; 222 buf->state = UVC_BUF_STATE_DONE; 223 list_del(&buf->queue); 224 video->fid ^= UVC_STREAM_FID; 225 ureq->last_buf = buf; 226 } 227 } 228 229 /* -------------------------------------------------------------------------- 230 * Request handling 231 */ 232 233 static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req) 234 { 235 int ret; 236 237 ret = usb_ep_queue(video->ep, req, GFP_ATOMIC); 238 if (ret < 0) { 239 uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n", 240 ret); 241 242 /* If the endpoint is disabled the descriptor may be NULL. */ 243 if (video->ep->desc) { 244 /* Isochronous endpoints can't be halted. */ 245 if (usb_endpoint_xfer_bulk(video->ep->desc)) 246 usb_ep_set_halt(video->ep); 247 } 248 } 249 250 return ret; 251 } 252 253 static void 254 uvc_video_complete(struct usb_ep *ep, struct usb_request *req) 255 { 256 struct uvc_request *ureq = req->context; 257 struct uvc_video *video = ureq->video; 258 struct uvc_video_queue *queue = &video->queue; 259 struct uvc_device *uvc = video->uvc; 260 unsigned long flags; 261 262 if (uvc->state == UVC_STATE_CONNECTED) { 263 usb_ep_free_request(video->ep, ureq->req); 264 ureq->req = NULL; 265 return; 266 } 267 268 switch (req->status) { 269 case 0: 270 break; 271 272 case -EXDEV: 273 uvcg_dbg(&video->uvc->func, "VS request missed xfer.\n"); 274 queue->flags |= UVC_QUEUE_DROP_INCOMPLETE; 275 break; 276 277 case -ESHUTDOWN: /* disconnect from host. */ 278 uvcg_dbg(&video->uvc->func, "VS request cancelled.\n"); 279 uvcg_queue_cancel(queue, 1); 280 break; 281 282 default: 283 uvcg_warn(&video->uvc->func, 284 "VS request completed with status %d.\n", 285 req->status); 286 uvcg_queue_cancel(queue, 0); 287 } 288 289 if (ureq->last_buf) { 290 uvcg_complete_buffer(&video->queue, ureq->last_buf); 291 ureq->last_buf = NULL; 292 } 293 294 spin_lock_irqsave(&video->req_lock, flags); 295 list_add_tail(&req->list, &video->req_free); 296 spin_unlock_irqrestore(&video->req_lock, flags); 297 298 if (uvc->state == UVC_STATE_STREAMING) 299 queue_work(video->async_wq, &video->pump); 300 } 301 302 static int 303 uvc_video_free_requests(struct uvc_video *video) 304 { 305 unsigned int i; 306 307 if (video->ureq) { 308 for (i = 0; i < video->uvc_num_requests; ++i) { 309 sg_free_table(&video->ureq[i].sgt); 310 311 if (video->ureq[i].req) { 312 usb_ep_free_request(video->ep, video->ureq[i].req); 313 video->ureq[i].req = NULL; 314 } 315 316 if (video->ureq[i].req_buffer) { 317 kfree(video->ureq[i].req_buffer); 318 video->ureq[i].req_buffer = NULL; 319 } 320 } 321 322 kfree(video->ureq); 323 video->ureq = NULL; 324 } 325 326 INIT_LIST_HEAD(&video->req_free); 327 video->req_size = 0; 328 return 0; 329 } 330 331 static int 332 uvc_video_alloc_requests(struct uvc_video *video) 333 { 334 unsigned int req_size; 335 unsigned int i; 336 int ret = -ENOMEM; 337 338 BUG_ON(video->req_size); 339 340 req_size = video->ep->maxpacket 341 * max_t(unsigned int, video->ep->maxburst, 1) 342 * (video->ep->mult); 343 344 video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL); 345 if (video->ureq == NULL) 346 return -ENOMEM; 347 348 for (i = 0; i < video->uvc_num_requests; ++i) { 349 video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL); 350 if (video->ureq[i].req_buffer == NULL) 351 goto error; 352 353 video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL); 354 if (video->ureq[i].req == NULL) 355 goto error; 356 357 video->ureq[i].req->buf = video->ureq[i].req_buffer; 358 video->ureq[i].req->length = 0; 359 video->ureq[i].req->complete = uvc_video_complete; 360 video->ureq[i].req->context = &video->ureq[i]; 361 video->ureq[i].video = video; 362 video->ureq[i].last_buf = NULL; 363 364 list_add_tail(&video->ureq[i].req->list, &video->req_free); 365 /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */ 366 sg_alloc_table(&video->ureq[i].sgt, 367 DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN, 368 PAGE_SIZE) + 2, GFP_KERNEL); 369 } 370 371 video->req_size = req_size; 372 373 return 0; 374 375 error: 376 uvc_video_free_requests(video); 377 return ret; 378 } 379 380 /* -------------------------------------------------------------------------- 381 * Video streaming 382 */ 383 384 /* 385 * uvcg_video_pump - Pump video data into the USB requests 386 * 387 * This function fills the available USB requests (listed in req_free) with 388 * video data from the queued buffers. 389 */ 390 static void uvcg_video_pump(struct work_struct *work) 391 { 392 struct uvc_video *video = container_of(work, struct uvc_video, pump); 393 struct uvc_video_queue *queue = &video->queue; 394 /* video->max_payload_size is only set when using bulk transfer */ 395 bool is_bulk = video->max_payload_size; 396 struct usb_request *req = NULL; 397 struct uvc_buffer *buf; 398 unsigned long flags; 399 bool buf_done; 400 int ret; 401 402 while (video->ep->enabled) { 403 /* 404 * Retrieve the first available USB request, protected by the 405 * request lock. 406 */ 407 spin_lock_irqsave(&video->req_lock, flags); 408 if (list_empty(&video->req_free)) { 409 spin_unlock_irqrestore(&video->req_lock, flags); 410 return; 411 } 412 req = list_first_entry(&video->req_free, struct usb_request, 413 list); 414 list_del(&req->list); 415 spin_unlock_irqrestore(&video->req_lock, flags); 416 417 /* 418 * Retrieve the first available video buffer and fill the 419 * request, protected by the video queue irqlock. 420 */ 421 spin_lock_irqsave(&queue->irqlock, flags); 422 buf = uvcg_queue_head(queue); 423 424 if (buf != NULL) { 425 video->encode(req, video, buf); 426 buf_done = buf->state == UVC_BUF_STATE_DONE; 427 } else if (!(queue->flags & UVC_QUEUE_DISCONNECTED) && !is_bulk) { 428 /* 429 * No video buffer available; the queue is still connected and 430 * we're transferring over ISOC. Queue a 0 length request to 431 * prevent missed ISOC transfers. 432 */ 433 req->length = 0; 434 buf_done = false; 435 } else { 436 /* 437 * Either the queue has been disconnected or no video buffer 438 * available for bulk transfer. Either way, stop processing 439 * further. 440 */ 441 spin_unlock_irqrestore(&queue->irqlock, flags); 442 break; 443 } 444 445 /* 446 * With USB3 handling more requests at a higher speed, we can't 447 * afford to generate an interrupt for every request. Decide to 448 * interrupt: 449 * 450 * - When no more requests are available in the free queue, as 451 * this may be our last chance to refill the endpoint's 452 * request queue. 453 * 454 * - When this is request is the last request for the video 455 * buffer, as we want to start sending the next video buffer 456 * ASAP in case it doesn't get started already in the next 457 * iteration of this loop. 458 * 459 * - Four times over the length of the requests queue (as 460 * indicated by video->uvc_num_requests), as a trade-off 461 * between latency and interrupt load. 462 */ 463 if (list_empty(&video->req_free) || buf_done || 464 !(video->req_int_count % 465 DIV_ROUND_UP(video->uvc_num_requests, 4))) { 466 video->req_int_count = 0; 467 req->no_interrupt = 0; 468 } else { 469 req->no_interrupt = 1; 470 } 471 472 /* Queue the USB request */ 473 ret = uvcg_video_ep_queue(video, req); 474 spin_unlock_irqrestore(&queue->irqlock, flags); 475 476 if (ret < 0) { 477 uvcg_queue_cancel(queue, 0); 478 break; 479 } 480 481 /* Endpoint now owns the request */ 482 req = NULL; 483 video->req_int_count++; 484 } 485 486 if (!req) 487 return; 488 489 spin_lock_irqsave(&video->req_lock, flags); 490 list_add_tail(&req->list, &video->req_free); 491 spin_unlock_irqrestore(&video->req_lock, flags); 492 return; 493 } 494 495 /* 496 * Enable or disable the video stream. 497 */ 498 int uvcg_video_enable(struct uvc_video *video, int enable) 499 { 500 unsigned int i; 501 int ret; 502 503 if (video->ep == NULL) { 504 uvcg_info(&video->uvc->func, 505 "Video enable failed, device is uninitialized.\n"); 506 return -ENODEV; 507 } 508 509 if (!enable) { 510 cancel_work_sync(&video->pump); 511 uvcg_queue_cancel(&video->queue, 0); 512 513 for (i = 0; i < video->uvc_num_requests; ++i) 514 if (video->ureq && video->ureq[i].req) 515 usb_ep_dequeue(video->ep, video->ureq[i].req); 516 517 uvc_video_free_requests(video); 518 uvcg_queue_enable(&video->queue, 0); 519 return 0; 520 } 521 522 if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0) 523 return ret; 524 525 if ((ret = uvc_video_alloc_requests(video)) < 0) 526 return ret; 527 528 if (video->max_payload_size) { 529 video->encode = uvc_video_encode_bulk; 530 video->payload_size = 0; 531 } else 532 video->encode = video->queue.use_sg ? 533 uvc_video_encode_isoc_sg : uvc_video_encode_isoc; 534 535 video->req_int_count = 0; 536 537 queue_work(video->async_wq, &video->pump); 538 539 return ret; 540 } 541 542 /* 543 * Initialize the UVC video stream. 544 */ 545 int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) 546 { 547 INIT_LIST_HEAD(&video->req_free); 548 spin_lock_init(&video->req_lock); 549 INIT_WORK(&video->pump, uvcg_video_pump); 550 551 /* Allocate a work queue for asynchronous video pump handler. */ 552 video->async_wq = alloc_workqueue("uvcgadget", WQ_UNBOUND | WQ_HIGHPRI, 0); 553 if (!video->async_wq) 554 return -EINVAL; 555 556 video->uvc = uvc; 557 video->fcc = V4L2_PIX_FMT_YUYV; 558 video->bpp = 16; 559 video->width = 320; 560 video->height = 240; 561 video->imagesize = 320 * 240 * 2; 562 563 /* Initialize the video buffers queue. */ 564 uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent, 565 V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex); 566 return 0; 567 } 568