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 27static int 28uvc_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 68static int 69uvc_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 86static void 87uvc_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 129static void 130uvc_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 196static void 197uvc_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 230static 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 250static void 251uvc_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 switch (req->status) { 260 case 0: 261 break; 262 263 case -EXDEV: 264 uvcg_dbg(&video->uvc->func, "VS request missed xfer.\n"); 265 queue->flags |= UVC_QUEUE_DROP_INCOMPLETE; 266 break; 267 268 case -ESHUTDOWN: /* disconnect from host. */ 269 uvcg_dbg(&video->uvc->func, "VS request cancelled.\n"); 270 uvcg_queue_cancel(queue, 1); 271 break; 272 273 default: 274 uvcg_warn(&video->uvc->func, 275 "VS request completed with status %d.\n", 276 req->status); 277 uvcg_queue_cancel(queue, 0); 278 } 279 280 if (ureq->last_buf) { 281 uvcg_complete_buffer(&video->queue, ureq->last_buf); 282 ureq->last_buf = NULL; 283 } 284 285 spin_lock_irqsave(&video->req_lock, flags); 286 list_add_tail(&req->list, &video->req_free); 287 spin_unlock_irqrestore(&video->req_lock, flags); 288 289 if (uvc->state == UVC_STATE_STREAMING) 290 queue_work(video->async_wq, &video->pump); 291} 292 293static int 294uvc_video_free_requests(struct uvc_video *video) 295{ 296 unsigned int i; 297 298 if (video->ureq) { 299 for (i = 0; i < video->uvc_num_requests; ++i) { 300 sg_free_table(&video->ureq[i].sgt); 301 302 if (video->ureq[i].req) { 303 usb_ep_free_request(video->ep, video->ureq[i].req); 304 video->ureq[i].req = NULL; 305 } 306 307 if (video->ureq[i].req_buffer) { 308 kfree(video->ureq[i].req_buffer); 309 video->ureq[i].req_buffer = NULL; 310 } 311 } 312 313 kfree(video->ureq); 314 video->ureq = NULL; 315 } 316 317 INIT_LIST_HEAD(&video->req_free); 318 video->req_size = 0; 319 return 0; 320} 321 322static int 323uvc_video_alloc_requests(struct uvc_video *video) 324{ 325 unsigned int req_size; 326 unsigned int i; 327 int ret = -ENOMEM; 328 329 BUG_ON(video->req_size); 330 331 req_size = video->ep->maxpacket 332 * max_t(unsigned int, video->ep->maxburst, 1) 333 * (video->ep->mult); 334 335 video->ureq = kcalloc(video->uvc_num_requests, sizeof(struct uvc_request), GFP_KERNEL); 336 if (video->ureq == NULL) 337 return -ENOMEM; 338 339 for (i = 0; i < video->uvc_num_requests; ++i) { 340 video->ureq[i].req_buffer = kmalloc(req_size, GFP_KERNEL); 341 if (video->ureq[i].req_buffer == NULL) 342 goto error; 343 344 video->ureq[i].req = usb_ep_alloc_request(video->ep, GFP_KERNEL); 345 if (video->ureq[i].req == NULL) 346 goto error; 347 348 video->ureq[i].req->buf = video->ureq[i].req_buffer; 349 video->ureq[i].req->length = 0; 350 video->ureq[i].req->complete = uvc_video_complete; 351 video->ureq[i].req->context = &video->ureq[i]; 352 video->ureq[i].video = video; 353 video->ureq[i].last_buf = NULL; 354 355 list_add_tail(&video->ureq[i].req->list, &video->req_free); 356 /* req_size/PAGE_SIZE + 1 for overruns and + 1 for header */ 357 sg_alloc_table(&video->ureq[i].sgt, 358 DIV_ROUND_UP(req_size - UVCG_REQUEST_HEADER_LEN, 359 PAGE_SIZE) + 2, GFP_KERNEL); 360 } 361 362 video->req_size = req_size; 363 364 return 0; 365 366error: 367 uvc_video_free_requests(video); 368 return ret; 369} 370 371/* -------------------------------------------------------------------------- 372 * Video streaming 373 */ 374 375/* 376 * uvcg_video_pump - Pump video data into the USB requests 377 * 378 * This function fills the available USB requests (listed in req_free) with 379 * video data from the queued buffers. 380 */ 381static void uvcg_video_pump(struct work_struct *work) 382{ 383 struct uvc_video *video = container_of(work, struct uvc_video, pump); 384 struct uvc_video_queue *queue = &video->queue; 385 /* video->max_payload_size is only set when using bulk transfer */ 386 bool is_bulk = video->max_payload_size; 387 struct usb_request *req = NULL; 388 struct uvc_buffer *buf; 389 unsigned long flags; 390 bool buf_done; 391 int ret; 392 393 while (video->ep->enabled) { 394 /* 395 * Retrieve the first available USB request, protected by the 396 * request lock. 397 */ 398 spin_lock_irqsave(&video->req_lock, flags); 399 if (list_empty(&video->req_free)) { 400 spin_unlock_irqrestore(&video->req_lock, flags); 401 return; 402 } 403 req = list_first_entry(&video->req_free, struct usb_request, 404 list); 405 list_del(&req->list); 406 spin_unlock_irqrestore(&video->req_lock, flags); 407 408 /* 409 * Retrieve the first available video buffer and fill the 410 * request, protected by the video queue irqlock. 411 */ 412 spin_lock_irqsave(&queue->irqlock, flags); 413 buf = uvcg_queue_head(queue); 414 415 if (buf != NULL) { 416 video->encode(req, video, buf); 417 buf_done = buf->state == UVC_BUF_STATE_DONE; 418 } else if (!(queue->flags & UVC_QUEUE_DISCONNECTED) && !is_bulk) { 419 /* 420 * No video buffer available; the queue is still connected and 421 * we're transferring over ISOC. Queue a 0 length request to 422 * prevent missed ISOC transfers. 423 */ 424 req->length = 0; 425 buf_done = false; 426 } else { 427 /* 428 * Either the queue has been disconnected or no video buffer 429 * available for bulk transfer. Either way, stop processing 430 * further. 431 */ 432 spin_unlock_irqrestore(&queue->irqlock, flags); 433 break; 434 } 435 436 /* 437 * With USB3 handling more requests at a higher speed, we can't 438 * afford to generate an interrupt for every request. Decide to 439 * interrupt: 440 * 441 * - When no more requests are available in the free queue, as 442 * this may be our last chance to refill the endpoint's 443 * request queue. 444 * 445 * - When this is request is the last request for the video 446 * buffer, as we want to start sending the next video buffer 447 * ASAP in case it doesn't get started already in the next 448 * iteration of this loop. 449 * 450 * - Four times over the length of the requests queue (as 451 * indicated by video->uvc_num_requests), as a trade-off 452 * between latency and interrupt load. 453 */ 454 if (list_empty(&video->req_free) || buf_done || 455 !(video->req_int_count % 456 DIV_ROUND_UP(video->uvc_num_requests, 4))) { 457 video->req_int_count = 0; 458 req->no_interrupt = 0; 459 } else { 460 req->no_interrupt = 1; 461 } 462 463 /* Queue the USB request */ 464 ret = uvcg_video_ep_queue(video, req); 465 spin_unlock_irqrestore(&queue->irqlock, flags); 466 467 if (ret < 0) { 468 uvcg_queue_cancel(queue, 0); 469 break; 470 } 471 472 /* Endpoint now owns the request */ 473 req = NULL; 474 video->req_int_count++; 475 } 476 477 if (!req) 478 return; 479 480 spin_lock_irqsave(&video->req_lock, flags); 481 list_add_tail(&req->list, &video->req_free); 482 spin_unlock_irqrestore(&video->req_lock, flags); 483 return; 484} 485 486/* 487 * Enable or disable the video stream. 488 */ 489int uvcg_video_enable(struct uvc_video *video, int enable) 490{ 491 unsigned int i; 492 int ret; 493 494 if (video->ep == NULL) { 495 uvcg_info(&video->uvc->func, 496 "Video enable failed, device is uninitialized.\n"); 497 return -ENODEV; 498 } 499 500 if (!enable) { 501 cancel_work_sync(&video->pump); 502 uvcg_queue_cancel(&video->queue, 0); 503 504 for (i = 0; i < video->uvc_num_requests; ++i) 505 if (video->ureq && video->ureq[i].req) 506 usb_ep_dequeue(video->ep, video->ureq[i].req); 507 508 uvc_video_free_requests(video); 509 uvcg_queue_enable(&video->queue, 0); 510 return 0; 511 } 512 513 if ((ret = uvcg_queue_enable(&video->queue, 1)) < 0) 514 return ret; 515 516 if ((ret = uvc_video_alloc_requests(video)) < 0) 517 return ret; 518 519 if (video->max_payload_size) { 520 video->encode = uvc_video_encode_bulk; 521 video->payload_size = 0; 522 } else 523 video->encode = video->queue.use_sg ? 524 uvc_video_encode_isoc_sg : uvc_video_encode_isoc; 525 526 video->req_int_count = 0; 527 528 queue_work(video->async_wq, &video->pump); 529 530 return ret; 531} 532 533/* 534 * Initialize the UVC video stream. 535 */ 536int uvcg_video_init(struct uvc_video *video, struct uvc_device *uvc) 537{ 538 INIT_LIST_HEAD(&video->req_free); 539 spin_lock_init(&video->req_lock); 540 INIT_WORK(&video->pump, uvcg_video_pump); 541 542 /* Allocate a work queue for asynchronous video pump handler. */ 543 video->async_wq = alloc_workqueue("uvcgadget", WQ_UNBOUND | WQ_HIGHPRI, 0); 544 if (!video->async_wq) 545 return -EINVAL; 546 547 video->uvc = uvc; 548 video->fcc = V4L2_PIX_FMT_YUYV; 549 video->bpp = 16; 550 video->width = 320; 551 video->height = 240; 552 video->imagesize = 320 * 240 * 2; 553 554 /* Initialize the video buffers queue. */ 555 uvcg_queue_init(&video->queue, uvc->v4l2_dev.dev->parent, 556 V4L2_BUF_TYPE_VIDEO_OUTPUT, &video->mutex); 557 return 0; 558} 559