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 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 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 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 */ 221 222 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 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 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 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 */ 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 */ 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 */ 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