1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * uvc_queue.c -- USB Video Class driver - Buffers management
5 * Copyright (C) 2005-2010
6 * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
9 #include <linux/atomic.h>
10 #include <linux/kernel.h>
12 #include <linux/list.h>
13 #include <linux/module.h>
14 #include <linux/usb.h>
15 #include <linux/videodev2.h>
16 #include <linux/vmalloc.h>
17 #include <linux/wait.h>
18 #include <media/videobuf2-v4l2.h>
19 #include <media/videobuf2-vmalloc.h>
23 /* ------------------------------------------------------------------------
24 * Video buffers queue management.
26 * Video queues is initialized by uvc_queue_init(). The function performs
27 * basic initialization of the uvc_video_queue struct and never fails.
29 * Video buffers are managed by videobuf2. The driver uses a mutex to protect
30 * the videobuf2 queue operations by serializing calls to videobuf2 and a
31 * spinlock to protect the IRQ queue that holds the buffers to be processed by
35 static inline struct uvc_buffer
*uvc_vbuf_to_buffer(struct vb2_v4l2_buffer
*buf
)
37 return container_of(buf
, struct uvc_buffer
, buf
);
41 * Return all queued buffers to videobuf2 in the requested state.
43 * This function must be called with the queue spinlock held.
45 static void uvc_queue_return_buffers(struct uvc_video_queue
*queue
,
46 enum uvc_buffer_state state
)
48 enum vb2_buffer_state vb2_state
= state
== UVC_BUF_STATE_ERROR
50 : VB2_BUF_STATE_QUEUED
;
52 while (!list_empty(&queue
->irqqueue
)) {
53 struct uvc_buffer
*buf
= list_first_entry(&queue
->irqqueue
,
56 list_del(&buf
->queue
);
58 vb2_buffer_done(&buf
->buf
.vb2_buf
, vb2_state
);
62 /* -----------------------------------------------------------------------------
63 * videobuf2 queue operations
66 static int uvc_queue_setup(struct vb2_queue
*vq
,
67 unsigned int *nbuffers
, unsigned int *nplanes
,
68 unsigned int sizes
[], struct device
*alloc_devs
[])
70 struct uvc_video_queue
*queue
= vb2_get_drv_priv(vq
);
71 struct uvc_streaming
*stream
;
75 case V4L2_BUF_TYPE_META_CAPTURE
:
76 size
= UVC_METADATA_BUF_SIZE
;
80 stream
= uvc_queue_to_stream(queue
);
81 size
= stream
->ctrl
.dwMaxVideoFrameSize
;
86 * When called with plane sizes, validate them. The driver supports
87 * single planar formats only, and requires buffers to be large enough
88 * to store a complete frame.
91 return *nplanes
!= 1 || sizes
[0] < size
? -EINVAL
: 0;
98 static int uvc_buffer_prepare(struct vb2_buffer
*vb
)
100 struct vb2_v4l2_buffer
*vbuf
= to_vb2_v4l2_buffer(vb
);
101 struct uvc_video_queue
*queue
= vb2_get_drv_priv(vb
->vb2_queue
);
102 struct uvc_buffer
*buf
= uvc_vbuf_to_buffer(vbuf
);
104 if (vb
->type
== V4L2_BUF_TYPE_VIDEO_OUTPUT
&&
105 vb2_get_plane_payload(vb
, 0) > vb2_plane_size(vb
, 0)) {
106 uvc_dbg(uvc_queue_to_stream(queue
)->dev
, CAPTURE
,
107 "[E] Bytes used out of bounds\n");
111 if (unlikely(queue
->flags
& UVC_QUEUE_DISCONNECTED
))
114 buf
->state
= UVC_BUF_STATE_QUEUED
;
116 buf
->mem
= vb2_plane_vaddr(vb
, 0);
117 buf
->length
= vb2_plane_size(vb
, 0);
118 if (vb
->type
!= V4L2_BUF_TYPE_VIDEO_OUTPUT
)
121 buf
->bytesused
= vb2_get_plane_payload(vb
, 0);
126 static void uvc_buffer_queue(struct vb2_buffer
*vb
)
128 struct vb2_v4l2_buffer
*vbuf
= to_vb2_v4l2_buffer(vb
);
129 struct uvc_video_queue
*queue
= vb2_get_drv_priv(vb
->vb2_queue
);
130 struct uvc_buffer
*buf
= uvc_vbuf_to_buffer(vbuf
);
133 spin_lock_irqsave(&queue
->irqlock
, flags
);
134 if (likely(!(queue
->flags
& UVC_QUEUE_DISCONNECTED
))) {
135 kref_init(&buf
->ref
);
136 list_add_tail(&buf
->queue
, &queue
->irqqueue
);
138 /* If the device is disconnected return the buffer to userspace
139 * directly. The next QBUF call will fail with -ENODEV.
141 buf
->state
= UVC_BUF_STATE_ERROR
;
142 vb2_buffer_done(vb
, VB2_BUF_STATE_ERROR
);
145 spin_unlock_irqrestore(&queue
->irqlock
, flags
);
148 static void uvc_buffer_finish(struct vb2_buffer
*vb
)
150 struct vb2_v4l2_buffer
*vbuf
= to_vb2_v4l2_buffer(vb
);
151 struct uvc_video_queue
*queue
= vb2_get_drv_priv(vb
->vb2_queue
);
152 struct uvc_streaming
*stream
= uvc_queue_to_stream(queue
);
153 struct uvc_buffer
*buf
= uvc_vbuf_to_buffer(vbuf
);
155 if (vb
->state
== VB2_BUF_STATE_DONE
)
156 uvc_video_clock_update(stream
, vbuf
, buf
);
159 static int uvc_start_streaming(struct vb2_queue
*vq
, unsigned int count
)
161 struct uvc_video_queue
*queue
= vb2_get_drv_priv(vq
);
162 struct uvc_streaming
*stream
= uvc_queue_to_stream(queue
);
165 lockdep_assert_irqs_enabled();
169 ret
= uvc_video_start_streaming(stream
);
173 spin_lock_irq(&queue
->irqlock
);
174 uvc_queue_return_buffers(queue
, UVC_BUF_STATE_QUEUED
);
175 spin_unlock_irq(&queue
->irqlock
);
180 static void uvc_stop_streaming(struct vb2_queue
*vq
)
182 struct uvc_video_queue
*queue
= vb2_get_drv_priv(vq
);
184 lockdep_assert_irqs_enabled();
186 if (vq
->type
!= V4L2_BUF_TYPE_META_CAPTURE
)
187 uvc_video_stop_streaming(uvc_queue_to_stream(queue
));
189 spin_lock_irq(&queue
->irqlock
);
190 uvc_queue_return_buffers(queue
, UVC_BUF_STATE_ERROR
);
191 spin_unlock_irq(&queue
->irqlock
);
194 static const struct vb2_ops uvc_queue_qops
= {
195 .queue_setup
= uvc_queue_setup
,
196 .buf_prepare
= uvc_buffer_prepare
,
197 .buf_queue
= uvc_buffer_queue
,
198 .buf_finish
= uvc_buffer_finish
,
199 .wait_prepare
= vb2_ops_wait_prepare
,
200 .wait_finish
= vb2_ops_wait_finish
,
201 .start_streaming
= uvc_start_streaming
,
202 .stop_streaming
= uvc_stop_streaming
,
205 static const struct vb2_ops uvc_meta_queue_qops
= {
206 .queue_setup
= uvc_queue_setup
,
207 .buf_prepare
= uvc_buffer_prepare
,
208 .buf_queue
= uvc_buffer_queue
,
209 .wait_prepare
= vb2_ops_wait_prepare
,
210 .wait_finish
= vb2_ops_wait_finish
,
211 .stop_streaming
= uvc_stop_streaming
,
214 int uvc_queue_init(struct uvc_video_queue
*queue
, enum v4l2_buf_type type
,
219 queue
->queue
.type
= type
;
220 queue
->queue
.io_modes
= VB2_MMAP
| VB2_USERPTR
;
221 queue
->queue
.drv_priv
= queue
;
222 queue
->queue
.buf_struct_size
= sizeof(struct uvc_buffer
);
223 queue
->queue
.mem_ops
= &vb2_vmalloc_memops
;
224 queue
->queue
.timestamp_flags
= V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC
225 | V4L2_BUF_FLAG_TSTAMP_SRC_SOE
;
226 queue
->queue
.lock
= &queue
->mutex
;
229 case V4L2_BUF_TYPE_META_CAPTURE
:
230 queue
->queue
.ops
= &uvc_meta_queue_qops
;
233 queue
->queue
.io_modes
|= VB2_DMABUF
;
234 queue
->queue
.ops
= &uvc_queue_qops
;
238 ret
= vb2_queue_init(&queue
->queue
);
242 mutex_init(&queue
->mutex
);
243 spin_lock_init(&queue
->irqlock
);
244 INIT_LIST_HEAD(&queue
->irqqueue
);
245 queue
->flags
= drop_corrupted
? UVC_QUEUE_DROP_CORRUPTED
: 0;
250 void uvc_queue_release(struct uvc_video_queue
*queue
)
252 mutex_lock(&queue
->mutex
);
253 vb2_queue_release(&queue
->queue
);
254 mutex_unlock(&queue
->mutex
);
257 /* -----------------------------------------------------------------------------
258 * V4L2 queue operations
261 int uvc_request_buffers(struct uvc_video_queue
*queue
,
262 struct v4l2_requestbuffers
*rb
)
266 mutex_lock(&queue
->mutex
);
267 ret
= vb2_reqbufs(&queue
->queue
, rb
);
268 mutex_unlock(&queue
->mutex
);
270 return ret
? ret
: rb
->count
;
273 int uvc_query_buffer(struct uvc_video_queue
*queue
, struct v4l2_buffer
*buf
)
277 mutex_lock(&queue
->mutex
);
278 ret
= vb2_querybuf(&queue
->queue
, buf
);
279 mutex_unlock(&queue
->mutex
);
284 int uvc_create_buffers(struct uvc_video_queue
*queue
,
285 struct v4l2_create_buffers
*cb
)
289 mutex_lock(&queue
->mutex
);
290 ret
= vb2_create_bufs(&queue
->queue
, cb
);
291 mutex_unlock(&queue
->mutex
);
296 int uvc_queue_buffer(struct uvc_video_queue
*queue
,
297 struct media_device
*mdev
, struct v4l2_buffer
*buf
)
301 mutex_lock(&queue
->mutex
);
302 ret
= vb2_qbuf(&queue
->queue
, mdev
, buf
);
303 mutex_unlock(&queue
->mutex
);
308 int uvc_export_buffer(struct uvc_video_queue
*queue
,
309 struct v4l2_exportbuffer
*exp
)
313 mutex_lock(&queue
->mutex
);
314 ret
= vb2_expbuf(&queue
->queue
, exp
);
315 mutex_unlock(&queue
->mutex
);
320 int uvc_dequeue_buffer(struct uvc_video_queue
*queue
, struct v4l2_buffer
*buf
,
325 mutex_lock(&queue
->mutex
);
326 ret
= vb2_dqbuf(&queue
->queue
, buf
, nonblocking
);
327 mutex_unlock(&queue
->mutex
);
332 int uvc_queue_streamon(struct uvc_video_queue
*queue
, enum v4l2_buf_type type
)
336 mutex_lock(&queue
->mutex
);
337 ret
= vb2_streamon(&queue
->queue
, type
);
338 mutex_unlock(&queue
->mutex
);
343 int uvc_queue_streamoff(struct uvc_video_queue
*queue
, enum v4l2_buf_type type
)
347 mutex_lock(&queue
->mutex
);
348 ret
= vb2_streamoff(&queue
->queue
, type
);
349 mutex_unlock(&queue
->mutex
);
354 int uvc_queue_mmap(struct uvc_video_queue
*queue
, struct vm_area_struct
*vma
)
356 return vb2_mmap(&queue
->queue
, vma
);
360 unsigned long uvc_queue_get_unmapped_area(struct uvc_video_queue
*queue
,
363 return vb2_get_unmapped_area(&queue
->queue
, 0, 0, pgoff
, 0);
367 __poll_t
uvc_queue_poll(struct uvc_video_queue
*queue
, struct file
*file
,
372 mutex_lock(&queue
->mutex
);
373 ret
= vb2_poll(&queue
->queue
, file
, wait
);
374 mutex_unlock(&queue
->mutex
);
379 /* -----------------------------------------------------------------------------
384 * Check if buffers have been allocated.
386 int uvc_queue_allocated(struct uvc_video_queue
*queue
)
390 mutex_lock(&queue
->mutex
);
391 allocated
= vb2_is_busy(&queue
->queue
);
392 mutex_unlock(&queue
->mutex
);
398 * Cancel the video buffers queue.
400 * Cancelling the queue marks all buffers on the irq queue as erroneous,
401 * wakes them up and removes them from the queue.
403 * If the disconnect parameter is set, further calls to uvc_queue_buffer will
406 * This function acquires the irq spinlock and can be called from interrupt
409 void uvc_queue_cancel(struct uvc_video_queue
*queue
, int disconnect
)
413 spin_lock_irqsave(&queue
->irqlock
, flags
);
414 uvc_queue_return_buffers(queue
, UVC_BUF_STATE_ERROR
);
415 /* This must be protected by the irqlock spinlock to avoid race
416 * conditions between uvc_buffer_queue and the disconnection event that
417 * could result in an interruptible wait in uvc_dequeue_buffer. Do not
418 * blindly replace this logic by checking for the UVC_QUEUE_DISCONNECTED
419 * state outside the queue code.
422 queue
->flags
|= UVC_QUEUE_DISCONNECTED
;
423 spin_unlock_irqrestore(&queue
->irqlock
, flags
);
427 * uvc_queue_get_current_buffer: Obtain the current working output buffer
429 * Buffers may span multiple packets, and even URBs, therefore the active buffer
430 * remains on the queue until the EOF marker.
432 static struct uvc_buffer
*
433 __uvc_queue_get_current_buffer(struct uvc_video_queue
*queue
)
435 if (list_empty(&queue
->irqqueue
))
438 return list_first_entry(&queue
->irqqueue
, struct uvc_buffer
, queue
);
441 struct uvc_buffer
*uvc_queue_get_current_buffer(struct uvc_video_queue
*queue
)
443 struct uvc_buffer
*nextbuf
;
446 spin_lock_irqsave(&queue
->irqlock
, flags
);
447 nextbuf
= __uvc_queue_get_current_buffer(queue
);
448 spin_unlock_irqrestore(&queue
->irqlock
, flags
);
454 * uvc_queue_buffer_requeue: Requeue a buffer on our internal irqqueue
456 * Reuse a buffer through our internal queue without the need to 'prepare'.
457 * The buffer will be returned to userspace through the uvc_buffer_queue call if
458 * the device has been disconnected.
460 static void uvc_queue_buffer_requeue(struct uvc_video_queue
*queue
,
461 struct uvc_buffer
*buf
)
464 buf
->state
= UVC_BUF_STATE_QUEUED
;
466 vb2_set_plane_payload(&buf
->buf
.vb2_buf
, 0, 0);
468 uvc_buffer_queue(&buf
->buf
.vb2_buf
);
471 static void uvc_queue_buffer_complete(struct kref
*ref
)
473 struct uvc_buffer
*buf
= container_of(ref
, struct uvc_buffer
, ref
);
474 struct vb2_buffer
*vb
= &buf
->buf
.vb2_buf
;
475 struct uvc_video_queue
*queue
= vb2_get_drv_priv(vb
->vb2_queue
);
477 if ((queue
->flags
& UVC_QUEUE_DROP_CORRUPTED
) && buf
->error
) {
478 uvc_queue_buffer_requeue(queue
, buf
);
482 buf
->state
= buf
->error
? UVC_BUF_STATE_ERROR
: UVC_BUF_STATE_DONE
;
483 vb2_set_plane_payload(&buf
->buf
.vb2_buf
, 0, buf
->bytesused
);
484 vb2_buffer_done(&buf
->buf
.vb2_buf
, VB2_BUF_STATE_DONE
);
488 * Release a reference on the buffer. Complete the buffer when the last
489 * reference is released.
491 void uvc_queue_buffer_release(struct uvc_buffer
*buf
)
493 kref_put(&buf
->ref
, uvc_queue_buffer_complete
);
497 * Remove this buffer from the queue. Lifetime will persist while async actions
498 * are still running (if any), and uvc_queue_buffer_release will give the buffer
499 * back to VB2 when all users have completed.
501 struct uvc_buffer
*uvc_queue_next_buffer(struct uvc_video_queue
*queue
,
502 struct uvc_buffer
*buf
)
504 struct uvc_buffer
*nextbuf
;
507 spin_lock_irqsave(&queue
->irqlock
, flags
);
508 list_del(&buf
->queue
);
509 nextbuf
= __uvc_queue_get_current_buffer(queue
);
510 spin_unlock_irqrestore(&queue
->irqlock
, flags
);
512 uvc_queue_buffer_release(buf
);