1 /* 2 * uvc_queue.c -- USB Video Class driver - Buffers management 3 * 4 * Copyright (C) 2005-2010 5 * Laurent Pinchart (laurent.pinchart@ideasonboard.com) 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 */ 13 14 #include <linux/atomic.h> 15 #include <linux/kernel.h> 16 #include <linux/mm.h> 17 #include <linux/list.h> 18 #include <linux/module.h> 19 #include <linux/usb.h> 20 #include <linux/videodev2.h> 21 #include <linux/vmalloc.h> 22 #include <linux/wait.h> 23 #include <media/videobuf2-v4l2.h> 24 #include <media/videobuf2-vmalloc.h> 25 26 #include "uvcvideo.h" 27 28 /* ------------------------------------------------------------------------ 29 * Video buffers queue management. 30 * 31 * Video queues is initialized by uvc_queue_init(). The function performs 32 * basic initialization of the uvc_video_queue struct and never fails. 33 * 34 * Video buffers are managed by videobuf2. The driver uses a mutex to protect 35 * the videobuf2 queue operations by serializing calls to videobuf2 and a 36 * spinlock to protect the IRQ queue that holds the buffers to be processed by 37 * the driver. 38 */ 39 40 static inline struct uvc_streaming * 41 uvc_queue_to_stream(struct uvc_video_queue *queue) 42 { 43 return container_of(queue, struct uvc_streaming, queue); 44 } 45 46 static inline struct uvc_buffer *uvc_vbuf_to_buffer(struct vb2_v4l2_buffer *buf) 47 { 48 return container_of(buf, struct uvc_buffer, buf); 49 } 50 51 /* 52 * Return all queued buffers to videobuf2 in the requested state. 53 * 54 * This function must be called with the queue spinlock held. 55 */ 56 static void uvc_queue_return_buffers(struct uvc_video_queue *queue, 57 enum uvc_buffer_state state) 58 { 59 enum vb2_buffer_state vb2_state = state == UVC_BUF_STATE_ERROR 60 ? VB2_BUF_STATE_ERROR 61 : VB2_BUF_STATE_QUEUED; 62 63 while (!list_empty(&queue->irqqueue)) { 64 struct uvc_buffer *buf = list_first_entry(&queue->irqqueue, 65 struct uvc_buffer, 66 queue); 67 list_del(&buf->queue); 68 buf->state = state; 69 vb2_buffer_done(&buf->buf.vb2_buf, vb2_state); 70 } 71 } 72 73 /* ----------------------------------------------------------------------------- 74 * videobuf2 queue operations 75 */ 76 77 static int uvc_queue_setup(struct vb2_queue *vq, 78 unsigned int *nbuffers, unsigned int *nplanes, 79 unsigned int sizes[], struct device *alloc_devs[]) 80 { 81 struct uvc_video_queue *queue = vb2_get_drv_priv(vq); 82 struct uvc_streaming *stream = uvc_queue_to_stream(queue); 83 unsigned size = stream->ctrl.dwMaxVideoFrameSize; 84 85 /* Make sure the image size is large enough. */ 86 if (*nplanes) 87 return sizes[0] < size ? -EINVAL : 0; 88 *nplanes = 1; 89 sizes[0] = size; 90 return 0; 91 } 92 93 static int uvc_buffer_prepare(struct vb2_buffer *vb) 94 { 95 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); 96 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); 97 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf); 98 99 if (vb->type == V4L2_BUF_TYPE_VIDEO_OUTPUT && 100 vb2_get_plane_payload(vb, 0) > vb2_plane_size(vb, 0)) { 101 uvc_trace(UVC_TRACE_CAPTURE, "[E] Bytes used out of bounds.\n"); 102 return -EINVAL; 103 } 104 105 if (unlikely(queue->flags & UVC_QUEUE_DISCONNECTED)) 106 return -ENODEV; 107 108 buf->state = UVC_BUF_STATE_QUEUED; 109 buf->error = 0; 110 buf->mem = vb2_plane_vaddr(vb, 0); 111 buf->length = vb2_plane_size(vb, 0); 112 if (vb->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) 113 buf->bytesused = 0; 114 else 115 buf->bytesused = vb2_get_plane_payload(vb, 0); 116 117 return 0; 118 } 119 120 static void uvc_buffer_queue(struct vb2_buffer *vb) 121 { 122 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); 123 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); 124 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf); 125 unsigned long flags; 126 127 spin_lock_irqsave(&queue->irqlock, flags); 128 if (likely(!(queue->flags & UVC_QUEUE_DISCONNECTED))) { 129 list_add_tail(&buf->queue, &queue->irqqueue); 130 } else { 131 /* If the device is disconnected return the buffer to userspace 132 * directly. The next QBUF call will fail with -ENODEV. 133 */ 134 buf->state = UVC_BUF_STATE_ERROR; 135 vb2_buffer_done(vb, VB2_BUF_STATE_ERROR); 136 } 137 138 spin_unlock_irqrestore(&queue->irqlock, flags); 139 } 140 141 static void uvc_buffer_finish(struct vb2_buffer *vb) 142 { 143 struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb); 144 struct uvc_video_queue *queue = vb2_get_drv_priv(vb->vb2_queue); 145 struct uvc_streaming *stream = uvc_queue_to_stream(queue); 146 struct uvc_buffer *buf = uvc_vbuf_to_buffer(vbuf); 147 148 if (vb->state == VB2_BUF_STATE_DONE) 149 uvc_video_clock_update(stream, vbuf, buf); 150 } 151 152 static int uvc_start_streaming(struct vb2_queue *vq, unsigned int count) 153 { 154 struct uvc_video_queue *queue = vb2_get_drv_priv(vq); 155 struct uvc_streaming *stream = uvc_queue_to_stream(queue); 156 unsigned long flags; 157 int ret; 158 159 queue->buf_used = 0; 160 161 ret = uvc_video_enable(stream, 1); 162 if (ret == 0) 163 return 0; 164 165 spin_lock_irqsave(&queue->irqlock, flags); 166 uvc_queue_return_buffers(queue, UVC_BUF_STATE_QUEUED); 167 spin_unlock_irqrestore(&queue->irqlock, flags); 168 169 return ret; 170 } 171 172 static void uvc_stop_streaming(struct vb2_queue *vq) 173 { 174 struct uvc_video_queue *queue = vb2_get_drv_priv(vq); 175 struct uvc_streaming *stream = uvc_queue_to_stream(queue); 176 unsigned long flags; 177 178 uvc_video_enable(stream, 0); 179 180 spin_lock_irqsave(&queue->irqlock, flags); 181 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR); 182 spin_unlock_irqrestore(&queue->irqlock, flags); 183 } 184 185 static const struct vb2_ops uvc_queue_qops = { 186 .queue_setup = uvc_queue_setup, 187 .buf_prepare = uvc_buffer_prepare, 188 .buf_queue = uvc_buffer_queue, 189 .buf_finish = uvc_buffer_finish, 190 .wait_prepare = vb2_ops_wait_prepare, 191 .wait_finish = vb2_ops_wait_finish, 192 .start_streaming = uvc_start_streaming, 193 .stop_streaming = uvc_stop_streaming, 194 }; 195 196 int uvc_queue_init(struct uvc_video_queue *queue, enum v4l2_buf_type type, 197 int drop_corrupted) 198 { 199 int ret; 200 201 queue->queue.type = type; 202 queue->queue.io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF; 203 queue->queue.drv_priv = queue; 204 queue->queue.buf_struct_size = sizeof(struct uvc_buffer); 205 queue->queue.ops = &uvc_queue_qops; 206 queue->queue.mem_ops = &vb2_vmalloc_memops; 207 queue->queue.timestamp_flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC 208 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE; 209 queue->queue.lock = &queue->mutex; 210 ret = vb2_queue_init(&queue->queue); 211 if (ret) 212 return ret; 213 214 mutex_init(&queue->mutex); 215 spin_lock_init(&queue->irqlock); 216 INIT_LIST_HEAD(&queue->irqqueue); 217 queue->flags = drop_corrupted ? UVC_QUEUE_DROP_CORRUPTED : 0; 218 219 return 0; 220 } 221 222 void uvc_queue_release(struct uvc_video_queue *queue) 223 { 224 mutex_lock(&queue->mutex); 225 vb2_queue_release(&queue->queue); 226 mutex_unlock(&queue->mutex); 227 } 228 229 /* ----------------------------------------------------------------------------- 230 * V4L2 queue operations 231 */ 232 233 int uvc_request_buffers(struct uvc_video_queue *queue, 234 struct v4l2_requestbuffers *rb) 235 { 236 int ret; 237 238 mutex_lock(&queue->mutex); 239 ret = vb2_reqbufs(&queue->queue, rb); 240 mutex_unlock(&queue->mutex); 241 242 return ret ? ret : rb->count; 243 } 244 245 int uvc_query_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf) 246 { 247 int ret; 248 249 mutex_lock(&queue->mutex); 250 ret = vb2_querybuf(&queue->queue, buf); 251 mutex_unlock(&queue->mutex); 252 253 return ret; 254 } 255 256 int uvc_create_buffers(struct uvc_video_queue *queue, 257 struct v4l2_create_buffers *cb) 258 { 259 int ret; 260 261 mutex_lock(&queue->mutex); 262 ret = vb2_create_bufs(&queue->queue, cb); 263 mutex_unlock(&queue->mutex); 264 265 return ret; 266 } 267 268 int uvc_queue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf) 269 { 270 int ret; 271 272 mutex_lock(&queue->mutex); 273 ret = vb2_qbuf(&queue->queue, buf); 274 mutex_unlock(&queue->mutex); 275 276 return ret; 277 } 278 279 int uvc_export_buffer(struct uvc_video_queue *queue, 280 struct v4l2_exportbuffer *exp) 281 { 282 int ret; 283 284 mutex_lock(&queue->mutex); 285 ret = vb2_expbuf(&queue->queue, exp); 286 mutex_unlock(&queue->mutex); 287 288 return ret; 289 } 290 291 int uvc_dequeue_buffer(struct uvc_video_queue *queue, struct v4l2_buffer *buf, 292 int nonblocking) 293 { 294 int ret; 295 296 mutex_lock(&queue->mutex); 297 ret = vb2_dqbuf(&queue->queue, buf, nonblocking); 298 mutex_unlock(&queue->mutex); 299 300 return ret; 301 } 302 303 int uvc_queue_streamon(struct uvc_video_queue *queue, enum v4l2_buf_type type) 304 { 305 int ret; 306 307 mutex_lock(&queue->mutex); 308 ret = vb2_streamon(&queue->queue, type); 309 mutex_unlock(&queue->mutex); 310 311 return ret; 312 } 313 314 int uvc_queue_streamoff(struct uvc_video_queue *queue, enum v4l2_buf_type type) 315 { 316 int ret; 317 318 mutex_lock(&queue->mutex); 319 ret = vb2_streamoff(&queue->queue, type); 320 mutex_unlock(&queue->mutex); 321 322 return ret; 323 } 324 325 int uvc_queue_mmap(struct uvc_video_queue *queue, struct vm_area_struct *vma) 326 { 327 return vb2_mmap(&queue->queue, vma); 328 } 329 330 #ifndef CONFIG_MMU 331 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue *queue, 332 unsigned long pgoff) 333 { 334 return vb2_get_unmapped_area(&queue->queue, 0, 0, pgoff, 0); 335 } 336 #endif 337 338 unsigned int uvc_queue_poll(struct uvc_video_queue *queue, struct file *file, 339 poll_table *wait) 340 { 341 unsigned int ret; 342 343 mutex_lock(&queue->mutex); 344 ret = vb2_poll(&queue->queue, file, wait); 345 mutex_unlock(&queue->mutex); 346 347 return ret; 348 } 349 350 /* ----------------------------------------------------------------------------- 351 * 352 */ 353 354 /* 355 * Check if buffers have been allocated. 356 */ 357 int uvc_queue_allocated(struct uvc_video_queue *queue) 358 { 359 int allocated; 360 361 mutex_lock(&queue->mutex); 362 allocated = vb2_is_busy(&queue->queue); 363 mutex_unlock(&queue->mutex); 364 365 return allocated; 366 } 367 368 /* 369 * Cancel the video buffers queue. 370 * 371 * Cancelling the queue marks all buffers on the irq queue as erroneous, 372 * wakes them up and removes them from the queue. 373 * 374 * If the disconnect parameter is set, further calls to uvc_queue_buffer will 375 * fail with -ENODEV. 376 * 377 * This function acquires the irq spinlock and can be called from interrupt 378 * context. 379 */ 380 void uvc_queue_cancel(struct uvc_video_queue *queue, int disconnect) 381 { 382 unsigned long flags; 383 384 spin_lock_irqsave(&queue->irqlock, flags); 385 uvc_queue_return_buffers(queue, UVC_BUF_STATE_ERROR); 386 /* This must be protected by the irqlock spinlock to avoid race 387 * conditions between uvc_buffer_queue and the disconnection event that 388 * could result in an interruptible wait in uvc_dequeue_buffer. Do not 389 * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED 390 * state outside the queue code. 391 */ 392 if (disconnect) 393 queue->flags |= UVC_QUEUE_DISCONNECTED; 394 spin_unlock_irqrestore(&queue->irqlock, flags); 395 } 396 397 struct uvc_buffer *uvc_queue_next_buffer(struct uvc_video_queue *queue, 398 struct uvc_buffer *buf) 399 { 400 struct uvc_buffer *nextbuf; 401 unsigned long flags; 402 403 if ((queue->flags & UVC_QUEUE_DROP_CORRUPTED) && buf->error) { 404 buf->error = 0; 405 buf->state = UVC_BUF_STATE_QUEUED; 406 buf->bytesused = 0; 407 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, 0); 408 return buf; 409 } 410 411 spin_lock_irqsave(&queue->irqlock, flags); 412 list_del(&buf->queue); 413 if (!list_empty(&queue->irqqueue)) 414 nextbuf = list_first_entry(&queue->irqqueue, struct uvc_buffer, 415 queue); 416 else 417 nextbuf = NULL; 418 spin_unlock_irqrestore(&queue->irqlock, flags); 419 420 buf->state = buf->error ? UVC_BUF_STATE_ERROR : UVC_BUF_STATE_DONE; 421 vb2_set_plane_payload(&buf->buf.vb2_buf, 0, buf->bytesused); 422 vb2_buffer_done(&buf->buf.vb2_buf, VB2_BUF_STATE_DONE); 423 424 return nextbuf; 425 } 426