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.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 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 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 struct uvc_request *ureq = req->context; 92 int len = video->req_size; 93 int ret; 94 95 /* Add a header at the beginning of the payload. */ 96 if (video->payload_size == 0) { 97 ret = uvc_video_encode_header(video, buf, mem, len); 98 video->payload_size += ret; 99 mem += ret; 100 len -= ret; 101 } 102 103 /* Process video data. */ 104 len = min((int)(video->max_payload_size - video->payload_size), len); 105 ret = uvc_video_encode_data(video, buf, mem, len); 106 107 video->payload_size += ret; 108 len -= ret; 109 110 req->length = video->req_size - len; 111 req->zero = video->payload_size == video->max_payload_size; 112 113 if (buf->bytesused == video->queue.buf_used) { 114 video->queue.buf_used = 0; 115 buf->state = UVC_BUF_STATE_DONE; 116 list_del(&buf->queue); 117 video->fid ^= UVC_STREAM_FID; 118 ureq->last_buf = buf; 119 120 video->payload_size = 0; 121 } 122 123 if (video->payload_size == video->max_payload_size || 124 video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE || 125 buf->bytesused == video->queue.buf_used) 126 video->payload_size = 0; 127 } 128 129 static void 130 uvc_video_encode_isoc_sg(struct usb_request *req, struct uvc_video *video, 131 struct uvc_buffer *buf) 132 { 133 unsigned int pending = buf->bytesused - video->queue.buf_used; 134 struct uvc_request *ureq = req->context; 135 struct scatterlist *sg, *iter; 136 unsigned int len = video->req_size; 137 unsigned int sg_left, part = 0; 138 unsigned int i; 139 int header_len; 140 141 sg = ureq->sgt.sgl; 142 sg_init_table(sg, ureq->sgt.nents); 143 144 /* Init the header. */ 145 header_len = uvc_video_encode_header(video, buf, ureq->header, 146 video->req_size); 147 sg_set_buf(sg, ureq->header, header_len); 148 len -= header_len; 149 150 if (pending <= len) 151 len = pending; 152 153 req->length = (len == pending) ? 154 len + header_len : video->req_size; 155 156 /* Init the pending sgs with payload */ 157 sg = sg_next(sg); 158 159 for_each_sg(sg, iter, ureq->sgt.nents - 1, i) { 160 if (!len || !buf->sg || !buf->sg->length) 161 break; 162 163 sg_left = buf->sg->length - buf->offset; 164 part = min_t(unsigned int, len, sg_left); 165 166 sg_set_page(iter, sg_page(buf->sg), part, buf->offset); 167 168 if (part == sg_left) { 169 buf->offset = 0; 170 buf->sg = sg_next(buf->sg); 171 } else { 172 buf->offset += part; 173 } 174 len -= part; 175 } 176 177 /* Assign the video data with header. */ 178 req->buf = NULL; 179 req->sg = ureq->sgt.sgl; 180 req->num_sgs = i + 1; 181 182 req->length -= len; 183 video->queue.buf_used += req->length - header_len; 184 185 if (buf->bytesused == video->queue.buf_used || !buf->sg || 186 video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) { 187 video->queue.buf_used = 0; 188 buf->state = UVC_BUF_STATE_DONE; 189 buf->offset = 0; 190 list_del(&buf->queue); 191 video->fid ^= UVC_STREAM_FID; 192 ureq->last_buf = buf; 193 } 194 } 195 196 static void 197 uvc_video_encode_isoc(struct usb_request *req, struct uvc_video *video, 198 struct uvc_buffer *buf) 199 { 200 void *mem = req->buf; 201 struct uvc_request *ureq = req->context; 202 int len = video->req_size; 203 int ret; 204 205 /* Add the header. */ 206 ret = uvc_video_encode_header(video, buf, mem, len); 207 mem += ret; 208 len -= ret; 209 210 /* Process video data. */ 211 ret = uvc_video_encode_data(video, buf, mem, len); 212 len -= ret; 213 214 req->length = video->req_size - len; 215 216 if (buf->bytesused == video->queue.buf_used || 217 video->queue.flags & UVC_QUEUE_DROP_INCOMPLETE) { 218 video->queue.buf_used = 0; 219 buf->state = UVC_BUF_STATE_DONE; 220 list_del(&buf->queue); 221 video->fid ^= UVC_STREAM_FID; 222 ureq->last_buf = buf; 223 } 224 } 225 226 /* -------------------------------------------------------------------------- 227 * Request handling 228 */ 229 230 static int uvcg_video_ep_queue(struct uvc_video *video, struct usb_request *req) 231 { 232 int ret; 233 234 ret = usb_ep_queue(video->ep, req, GFP_ATOMIC); 235 if (ret < 0) { 236 uvcg_err(&video->uvc->func, "Failed to queue request (%d).\n", 237 ret); 238 239 /* If the endpoint is disabled the descriptor may be NULL. */ 240 if (video->ep->desc) { 241 /* Isochronous endpoints can't be halted. */ 242 if (usb_endpoint_xfer_bulk(video->ep->desc)) 243 usb_ep_set_halt(video->ep); 244 } 245 } 246 247 return ret; 248 } 249 250 static void 251 uvc_video_complete(struct usb_ep *ep, struct usb_request *req) 252 { 253 struct uvc_request *ureq = req->context; 254 struct uvc_video *video = ureq->video; 255 struct uvc_video_queue *queue = &video->queue; 256 struct uvc_device *uvc = video->uvc; 257 unsigned long flags; 258 259 if (uvc->state == UVC_STATE_CONNECTED) { 260 usb_ep_free_request(video->ep, ureq->req); 261 ureq->req = NULL; 262 return; 263 } 264 265 switch (req->status) { 266 case 0: 267 break; 268 269 case -EXDEV: 270 uvcg_dbg(&video->uvc->func, "VS request missed xfer.\n"); 271 queue->flags |= UVC_QUEUE_DROP_INCOMPLETE; 272 break; 273 274 case -ESHUTDOWN: /* disconnect from host. */ 275 uvcg_dbg(&video->uvc->func, "VS request cancelled.\n"); 276 uvcg_queue_cancel(queue, 1); 277 break; 278 279 default: 280 uvcg_warn(&video->uvc->func, 281 "VS request completed with status %d.\n", 282 req->status); 283 uvcg_queue_cancel(queue, 0); 284 } 285 286 if (ureq->last_buf) { 287 uvcg_complete_buffer(&video->queue, ureq->last_buf); 288 ureq->last_buf = NULL; 289 } 290 291 spin_lock_irqsave(&video->req_lock, flags); 292 list_add_tail(&req->list, &video->req_free); 293 spin_unlock_irqrestore(&video->req_lock, flags); 294 295 if (uvc->state == UVC_STATE_STREAMING) 296 queue_work(video->async_wq, &video->pump); 297 } 298 299 static int 300 uvc_video_free_requests(struct uvc_video *video) 301 { 302 unsigned int i; 303 304 if (video->ureq) { 305 for (i = 0; i < video->uvc_num_requests; ++i) { 306 sg_free_table(&video->ureq[i].sgt); 307 308 if (video->ureq[i].req) { 309 usb_ep_free_request(video->ep, video->ureq[i].req); 310 video->ureq[i].req = NULL; 311 } 312 313 if (video->ureq[i].req_buffer) { 314 kfree(video->ureq[i].req_buffer); 315 video->ureq[i].req_buffer = NULL; 316 } 317 } 318 319 kfree(video->ureq); 320 video->ureq = NULL; 321 } 322 323 INIT_LIST_HEAD(&video->req_free); 324 video->req_size = 0; 325 return 0; 326 } 327 328 static int 329 uvc_video_alloc_requests(struct uvc_video *video) 330 { 331 unsigned int req_size; 332 unsigned int i; 333 int ret = -ENOMEM; 334 335 BUG_ON(video->req_size); 336 337 req_size = video->ep->maxpacket 338 * max_t(unsigned int, video->ep->maxburst, 1) 339 * (video->ep->mult); 340 341 video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL); 342 if (video->ureq == NULL) 343 return -ENOMEM; 344 345 for (i = 0; i < video->uvc_num_requests; ++i) { 346 video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL); 347 if (video->ureq[i].req_buffer == NULL) 348 goto error; 349 350 video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL); 351 if (video->ureq[i].req == NULL) 352 goto error; 353 354 video->ureq[i].req->buf = video->ureq[i].req_buffer; 355 video->ureq[i].req->length = 0; 356 video->ureq[i].req->complete = uvc_video_complete; 357 video->ureq[i].req->context = &video->ureq[i]; 358 video->ureq[i].video = video; 359 video->ureq[i].last_buf = NULL; 360 361 list_add_tail(&video->ureq[i].req->list, &video->req_free); 362 /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */ 363 sg_alloc_table(&video->ureq[i].sgt, 364 DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN, 365 PAGE_SIZE) + 2, GFP_KERNEL); 366 } 367 368 video->req_size = req_size; 369 370 return 0; 371 372 error: 373 uvc_video_free_requests(video); 374 return ret; 375 } 376 377 /* -------------------------------------------------------------------------- 378 * Video streaming 379 */ 380 381 /* 382 * uvcg_video_pump - Pump video data into the USB requests 383 * 384 * This function fills the available USB requests (listed in req_free) with 385 * video data from the queued buffers. 386 */ 387 static void uvcg_video_pump(struct work_struct *work) 388 { 389 struct uvc_video *video = container_of(work, struct uvc_video, pump); 390 struct uvc_video_queue *queue = &video->queue; 391 /* video->max_payload_size is only set when using bulk transfer */ 392 bool is_bulk = video->max_payload_size; 393 struct uvc_device *uvc = video->uvc; 394 struct usb_request *req = NULL; 395 struct uvc_buffer *buf; 396 unsigned long flags; 397 bool buf_done; 398 int ret; 399 400 if (video->ep->enabled && uvc->state == UVC_STATE_STREAMING) { 401 /* 402 * Retrieve the first available USB request, protected by the 403 * request lock. 404 */ 405 spin_lock_irqsave(&video->req_lock, flags); 406 if (list_empty(&video->req_free)) { 407 spin_unlock_irqrestore(&video->req_lock, flags); 408 return; 409 } 410 req = list_first_entry(&video->req_free, struct usb_request, 411 list); 412 if (!req) { 413 spin_unlock_irqrestore(&video->req_lock, flags); 414 return; 415 } 416 417 list_del(&req->list); 418 spin_unlock_irqrestore(&video->req_lock, flags); 419 420 /* 421 * Retrieve the first available video buffer and fill the 422 * request, protected by the video queue irqlock. 423 */ 424 spin_lock_irqsave(&queue->irqlock, flags); 425 buf = uvcg_queue_head(queue); 426 427 if (buf != NULL) { 428 video->encode(req, video, buf); 429 buf_done = buf->state == UVC_BUF_STATE_DONE; 430 } else if (!(queue->flags & UVC_QUEUE_DISCONNECTED) && !is_bulk) { 431 /* 432 * No video buffer available; the queue is still connected and 433 * we're transferring over ISOC. Queue a 0 length request to 434 * prevent missed ISOC transfers. 435 */ 436 req->length = 0; 437 buf_done = false; 438 } else { 439 /* 440 * Either the queue has been disconnected or no video buffer 441 * available for bulk transfer. Either way, stop processing 442 * further. 443 */ 444 spin_unlock_irqrestore(&queue->irqlock, flags); 445 goto out; 446 } 447 448 /* 449 * With USB3 handling more requests at a higher speed, we can't 450 * afford to generate an interrupt for every request. Decide to 451 * interrupt: 452 * 453 * - When no more requests are available in the free queue, as 454 * this may be our last chance to refill the endpoint's 455 * request queue. 456 * 457 * - When this is request is the last request for the video 458 * buffer, as we want to start sending the next video buffer 459 * ASAP in case it doesn't get started already in the next 460 * iteration of this loop. 461 * 462 * - Four times over the length of the requests queue (as 463 * indicated by video->uvc_num_requests), as a trade-off 464 * between latency and interrupt load. 465 */ 466 if (list_empty(&video->req_free) || buf_done || 467 !(video->req_int_count % 468 DIV_ROUND_UP(video->uvc_num_requests, 4))) { 469 video->req_int_count = 0; 470 req->no_interrupt = 0; 471 } else { 472 req->no_interrupt = 1; 473 } 474 475 /* Queue the USB request */ 476 ret = uvcg_video_ep_queue(video, req); 477 spin_unlock_irqrestore(&queue->irqlock, flags); 478 if (ret < 0) { 479 uvcg_queue_cancel(queue, 0); 480 goto out; 481 } 482 483 /* Endpoint now owns the request */ 484 req = NULL; 485 video->req_int_count++; 486 } else { 487 return; 488 } 489 490 if (uvc->state == UVC_STATE_STREAMING) 491 queue_work(video->async_wq, &video->pump); 492 493 return; 494 out: 495 spin_lock_irqsave(&video->req_lock, flags); 496 list_add_tail(&req->list, &video->req_free); 497 spin_unlock_irqrestore(&video->req_lock, flags); 498 return; 499 } 500 501 /* 502 * Enable or disable the video stream. 503 */ 504 int uvcg_video_enable(struct uvc_video *video, int enable) 505 { 506 struct uvc_device *uvc = video->uvc; 507 unsigned int i; 508 int ret; 509 510 if (video->ep == NULL) { 511 uvcg_info(&video->uvc->func, 512 "Video enable failed, device is uninitialized.\n"); 513 return -ENODEV; 514 } 515 516 if (!enable) { 517 uvc->state = UVC_STATE_CONNECTED; 518 519 cancel_work_sync(&video->pump); 520 uvcg_queue_cancel(&video->queue, 0); 521 522 for (i = 0; i < video->uvc_num_requests; ++i) 523 if (video->ureq && video->ureq[i].req) 524 usb_ep_dequeue(video->ep, video->ureq[i].req); 525 526 uvc_video_free_requests(video); 527 uvcg_queue_enable(&video->queue, 0); 528 return 0; 529 } 530 531 if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0) 532 return ret; 533 534 if ((ret = uvc_video_alloc_requests(video)) < 0) 535 return ret; 536 537 if (video->max_payload_size) { 538 video->encode = uvc_video_encode_bulk; 539 video->payload_size = 0; 540 } else 541 video->encode = video->queue.use_sg ? 542 uvc_video_encode_isoc_sg : uvc_video_encode_isoc; 543 544 uvc->state = UVC_STATE_STREAMING; 545 546 video->req_int_count = 0; 547 548 queue_work(video->async_wq, &video->pump); 549 550 return ret; 551 } 552 553 /* 554 * Initialize the UVC video stream. 555 */ 556 int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) 557 { 558 INIT_LIST_HEAD(&video->req_free); 559 spin_lock_init(&video->req_lock); 560 INIT_WORK(&video->pump, uvcg_video_pump); 561 562 /* Allocate a work queue for asynchronous video pump handler. */ 563 video->async_wq = alloc_workqueue("uvcgadget", WQ_UNBOUND | WQ_HIGHPRI, 0); 564 if (!video->async_wq) 565 return -EINVAL; 566 567 video->uvc = uvc; 568 video->fcc = V4L2_PIX_FMT_YUYV; 569 video->bpp = 16; 570 video->width = 320; 571 video->height = 240; 572 video->imagesize = 320 * 240 * 2; 573 574 /* Initialize the video buffers queue. */ 575 uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent, 576 V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex); 577 return 0; 578 } 579