2 * videobuf2-core.c - V4L2 driver helper framework
4 * Copyright (C) 2010 Samsung Electronics
6 * Author: Pawel Osciak <pawel@osciak.com>
7 * Marek Szyprowski <m.szyprowski@samsung.com>
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation.
14 #include <linux/err.h>
15 #include <linux/kernel.h>
16 #include <linux/module.h>
18 #include <linux/poll.h>
19 #include <linux/slab.h>
20 #include <linux/sched.h>
22 #include <media/v4l2-dev.h>
23 #include <media/v4l2-fh.h>
24 #include <media/v4l2-event.h>
25 #include <media/videobuf2-core.h>
28 module_param(debug, int, 0644);
30 #define dprintk(level, fmt, arg...) \
33 printk(KERN_DEBUG "vb2: " fmt, ## arg); \
36 #define call_memop(q, op, args...) \
37 (((q)->mem_ops->op) ? \
38 ((q)->mem_ops->op(args)) : 0)
40 #define call_qop(q, op, args...) \
41 (((q)->ops->op) ? ((q)->ops->op(args)) : 0)
43 #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \
44 V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \
45 V4L2_BUF_FLAG_PREPARED | \
46 V4L2_BUF_FLAG_TIMESTAMP_MASK)
49 * __vb2_buf_mem_alloc() - allocate video memory for the given buffer
51 static int __vb2_buf_mem_alloc(struct vb2_buffer *vb)
53 struct vb2_queue *q = vb->vb2_queue;
58 * Allocate memory for all planes in this buffer
59 * NOTE: mmapped areas should be page aligned
61 for (plane = 0; plane < vb->num_planes; ++plane) {
62 unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]);
64 mem_priv = call_memop(q, alloc, q->alloc_ctx[plane],
66 if (IS_ERR_OR_NULL(mem_priv))
69 /* Associate allocator private data with this plane */
70 vb->planes[plane].mem_priv = mem_priv;
71 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
76 /* Free already allocated memory if one of the allocations failed */
77 for (; plane > 0; --plane) {
78 call_memop(q, put, vb->planes[plane - 1].mem_priv);
79 vb->planes[plane - 1].mem_priv = NULL;
86 * __vb2_buf_mem_free() - free memory of the given buffer
88 static void __vb2_buf_mem_free(struct vb2_buffer *vb)
90 struct vb2_queue *q = vb->vb2_queue;
93 for (plane = 0; plane < vb->num_planes; ++plane) {
94 call_memop(q, put, vb->planes[plane].mem_priv);
95 vb->planes[plane].mem_priv = NULL;
96 dprintk(3, "Freed plane %d of buffer %d\n", plane,
102 * __vb2_buf_userptr_put() - release userspace memory associated with
105 static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
107 struct vb2_queue *q = vb->vb2_queue;
110 for (plane = 0; plane < vb->num_planes; ++plane) {
111 if (vb->planes[plane].mem_priv)
112 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
113 vb->planes[plane].mem_priv = NULL;
118 * __vb2_plane_dmabuf_put() - release memory associated with
119 * a DMABUF shared plane
121 static void __vb2_plane_dmabuf_put(struct vb2_queue *q, struct vb2_plane *p)
127 call_memop(q, unmap_dmabuf, p->mem_priv);
129 call_memop(q, detach_dmabuf, p->mem_priv);
130 dma_buf_put(p->dbuf);
131 memset(p, 0, sizeof(*p));
135 * __vb2_buf_dmabuf_put() - release memory associated with
136 * a DMABUF shared buffer
138 static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
140 struct vb2_queue *q = vb->vb2_queue;
143 for (plane = 0; plane < vb->num_planes; ++plane)
144 __vb2_plane_dmabuf_put(q, &vb->planes[plane]);
148 * __setup_lengths() - setup initial lengths for every plane in
149 * every buffer on the queue
151 static void __setup_lengths(struct vb2_queue *q, unsigned int n)
153 unsigned int buffer, plane;
154 struct vb2_buffer *vb;
156 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
157 vb = q->bufs[buffer];
161 for (plane = 0; plane < vb->num_planes; ++plane)
162 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
167 * __setup_offsets() - setup unique offsets ("cookies") for every plane in
168 * every buffer on the queue
170 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
172 unsigned int buffer, plane;
173 struct vb2_buffer *vb;
176 if (q->num_buffers) {
177 struct v4l2_plane *p;
178 vb = q->bufs[q->num_buffers - 1];
179 p = &vb->v4l2_planes[vb->num_planes - 1];
180 off = PAGE_ALIGN(p->m.mem_offset + p->length);
185 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
186 vb = q->bufs[buffer];
190 for (plane = 0; plane < vb->num_planes; ++plane) {
191 vb->v4l2_planes[plane].m.mem_offset = off;
193 dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
196 off += vb->v4l2_planes[plane].length;
197 off = PAGE_ALIGN(off);
203 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
204 * video buffer memory for all buffers/planes on the queue and initializes the
207 * Returns the number of buffers successfully allocated.
209 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
210 unsigned int num_buffers, unsigned int num_planes)
213 struct vb2_buffer *vb;
216 for (buffer = 0; buffer < num_buffers; ++buffer) {
217 /* Allocate videobuf buffer structures */
218 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
220 dprintk(1, "Memory alloc for buffer struct failed\n");
224 /* Length stores number of planes for multiplanar buffers */
225 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
226 vb->v4l2_buf.length = num_planes;
228 vb->state = VB2_BUF_STATE_DEQUEUED;
230 vb->num_planes = num_planes;
231 vb->v4l2_buf.index = q->num_buffers + buffer;
232 vb->v4l2_buf.type = q->type;
233 vb->v4l2_buf.memory = memory;
235 /* Allocate video buffer memory for the MMAP type */
236 if (memory == V4L2_MEMORY_MMAP) {
237 ret = __vb2_buf_mem_alloc(vb);
239 dprintk(1, "Failed allocating memory for "
240 "buffer %d\n", buffer);
245 * Call the driver-provided buffer initialization
246 * callback, if given. An error in initialization
247 * results in queue setup failure.
249 ret = call_qop(q, buf_init, vb);
251 dprintk(1, "Buffer %d %p initialization"
252 " failed\n", buffer, vb);
253 __vb2_buf_mem_free(vb);
259 q->bufs[q->num_buffers + buffer] = vb;
262 __setup_lengths(q, buffer);
263 if (memory == V4L2_MEMORY_MMAP)
264 __setup_offsets(q, buffer);
266 dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
273 * __vb2_free_mem() - release all video buffer memory for a given queue
275 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
278 struct vb2_buffer *vb;
280 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
282 vb = q->bufs[buffer];
286 /* Free MMAP buffers or release USERPTR buffers */
287 if (q->memory == V4L2_MEMORY_MMAP)
288 __vb2_buf_mem_free(vb);
289 else if (q->memory == V4L2_MEMORY_DMABUF)
290 __vb2_buf_dmabuf_put(vb);
292 __vb2_buf_userptr_put(vb);
297 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
298 * related information, if no buffers are left return the queue to an
299 * uninitialized state. Might be called even if the queue has already been freed.
301 static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
306 * Sanity check: when preparing a buffer the queue lock is released for
307 * a short while (see __buf_prepare for the details), which would allow
308 * a race with a reqbufs which can call this function. Removing the
309 * buffers from underneath __buf_prepare is obviously a bad idea, so we
310 * check if any of the buffers is in the state PREPARING, and if so we
311 * just return -EAGAIN.
313 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
315 if (q->bufs[buffer] == NULL)
317 if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) {
318 dprintk(1, "reqbufs: preparing buffers, cannot free\n");
323 /* Call driver-provided cleanup function for each buffer, if provided */
324 if (q->ops->buf_cleanup) {
325 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
327 if (NULL == q->bufs[buffer])
329 q->ops->buf_cleanup(q->bufs[buffer]);
333 /* Release video buffer memory */
334 __vb2_free_mem(q, buffers);
336 /* Free videobuf buffers */
337 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
339 kfree(q->bufs[buffer]);
340 q->bufs[buffer] = NULL;
343 q->num_buffers -= buffers;
346 INIT_LIST_HEAD(&q->queued_list);
351 * __verify_planes_array() - verify that the planes array passed in struct
352 * v4l2_buffer from userspace can be safely used
354 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
356 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
359 /* Is memory for copying plane information present? */
360 if (NULL == b->m.planes) {
361 dprintk(1, "Multi-planar buffer passed but "
362 "planes array not provided\n");
366 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
367 dprintk(1, "Incorrect planes array length, "
368 "expected %d, got %d\n", vb->num_planes, b->length);
376 * __verify_length() - Verify that the bytesused value for each plane fits in
377 * the plane length and that the data offset doesn't exceed the bytesused value.
379 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
384 if (!V4L2_TYPE_IS_OUTPUT(b->type))
387 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
388 for (plane = 0; plane < vb->num_planes; ++plane) {
389 length = (b->memory == V4L2_MEMORY_USERPTR)
390 ? b->m.planes[plane].length
391 : vb->v4l2_planes[plane].length;
393 if (b->m.planes[plane].bytesused > length)
396 if (b->m.planes[plane].data_offset > 0 &&
397 b->m.planes[plane].data_offset >=
398 b->m.planes[plane].bytesused)
402 length = (b->memory == V4L2_MEMORY_USERPTR)
403 ? b->length : vb->v4l2_planes[0].length;
405 if (b->bytesused > length)
413 * __buffer_in_use() - return true if the buffer is in use and
414 * the queue cannot be freed (by the means of REQBUFS(0)) call
416 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
419 for (plane = 0; plane < vb->num_planes; ++plane) {
420 void *mem_priv = vb->planes[plane].mem_priv;
422 * If num_users() has not been provided, call_memop
423 * will return 0, apparently nobody cares about this
424 * case anyway. If num_users() returns more than 1,
425 * we are not the only user of the plane's memory.
427 if (mem_priv && call_memop(q, num_users, mem_priv) > 1)
434 * __buffers_in_use() - return true if any buffers on the queue are in use and
435 * the queue cannot be freed (by the means of REQBUFS(0)) call
437 static bool __buffers_in_use(struct vb2_queue *q)
440 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
441 if (__buffer_in_use(q, q->bufs[buffer]))
448 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
449 * returned to userspace
451 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
453 struct vb2_queue *q = vb->vb2_queue;
455 /* Copy back data such as timestamp, flags, etc. */
456 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
457 b->reserved2 = vb->v4l2_buf.reserved2;
458 b->reserved = vb->v4l2_buf.reserved;
460 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
462 * Fill in plane-related data if userspace provided an array
463 * for it. The caller has already verified memory and size.
465 b->length = vb->num_planes;
466 memcpy(b->m.planes, vb->v4l2_planes,
467 b->length * sizeof(struct v4l2_plane));
470 * We use length and offset in v4l2_planes array even for
471 * single-planar buffers, but userspace does not.
473 b->length = vb->v4l2_planes[0].length;
474 b->bytesused = vb->v4l2_planes[0].bytesused;
475 if (q->memory == V4L2_MEMORY_MMAP)
476 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
477 else if (q->memory == V4L2_MEMORY_USERPTR)
478 b->m.userptr = vb->v4l2_planes[0].m.userptr;
479 else if (q->memory == V4L2_MEMORY_DMABUF)
480 b->m.fd = vb->v4l2_planes[0].m.fd;
484 * Clear any buffer state related flags.
486 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
487 b->flags |= q->timestamp_type;
490 case VB2_BUF_STATE_QUEUED:
491 case VB2_BUF_STATE_ACTIVE:
492 b->flags |= V4L2_BUF_FLAG_QUEUED;
494 case VB2_BUF_STATE_ERROR:
495 b->flags |= V4L2_BUF_FLAG_ERROR;
497 case VB2_BUF_STATE_DONE:
498 b->flags |= V4L2_BUF_FLAG_DONE;
500 case VB2_BUF_STATE_PREPARED:
501 b->flags |= V4L2_BUF_FLAG_PREPARED;
503 case VB2_BUF_STATE_PREPARING:
504 case VB2_BUF_STATE_DEQUEUED:
509 if (__buffer_in_use(q, vb))
510 b->flags |= V4L2_BUF_FLAG_MAPPED;
514 * vb2_querybuf() - query video buffer information
516 * @b: buffer struct passed from userspace to vidioc_querybuf handler
519 * Should be called from vidioc_querybuf ioctl handler in driver.
520 * This function will verify the passed v4l2_buffer structure and fill the
521 * relevant information for the userspace.
523 * The return values from this function are intended to be directly returned
524 * from vidioc_querybuf handler in driver.
526 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
528 struct vb2_buffer *vb;
531 if (b->type != q->type) {
532 dprintk(1, "querybuf: wrong buffer type\n");
536 if (b->index >= q->num_buffers) {
537 dprintk(1, "querybuf: buffer index out of range\n");
540 vb = q->bufs[b->index];
541 ret = __verify_planes_array(vb, b);
543 __fill_v4l2_buffer(vb, b);
546 EXPORT_SYMBOL(vb2_querybuf);
549 * __verify_userptr_ops() - verify that all memory operations required for
550 * USERPTR queue type have been provided
552 static int __verify_userptr_ops(struct vb2_queue *q)
554 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
555 !q->mem_ops->put_userptr)
562 * __verify_mmap_ops() - verify that all memory operations required for
563 * MMAP queue type have been provided
565 static int __verify_mmap_ops(struct vb2_queue *q)
567 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
568 !q->mem_ops->put || !q->mem_ops->mmap)
575 * __verify_dmabuf_ops() - verify that all memory operations required for
576 * DMABUF queue type have been provided
578 static int __verify_dmabuf_ops(struct vb2_queue *q)
580 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
581 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
582 !q->mem_ops->unmap_dmabuf)
589 * __verify_memory_type() - Check whether the memory type and buffer type
590 * passed to a buffer operation are compatible with the queue.
592 static int __verify_memory_type(struct vb2_queue *q,
593 enum v4l2_memory memory, enum v4l2_buf_type type)
595 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
596 memory != V4L2_MEMORY_DMABUF) {
597 dprintk(1, "reqbufs: unsupported memory type\n");
601 if (type != q->type) {
602 dprintk(1, "reqbufs: requested type is incorrect\n");
607 * Make sure all the required memory ops for given memory type
610 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
611 dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
615 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
616 dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
620 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
621 dprintk(1, "reqbufs: DMABUF for current setup unsupported\n");
626 * Place the busy tests at the end: -EBUSY can be ignored when
627 * create_bufs is called with count == 0, but count == 0 should still
628 * do the memory and type validation.
631 dprintk(1, "reqbufs: file io in progress\n");
638 * __reqbufs() - Initiate streaming
639 * @q: videobuf2 queue
640 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
642 * Should be called from vidioc_reqbufs ioctl handler of a driver.
644 * 1) verifies streaming parameters passed from the userspace,
645 * 2) sets up the queue,
646 * 3) negotiates number of buffers and planes per buffer with the driver
647 * to be used during streaming,
648 * 4) allocates internal buffer structures (struct vb2_buffer), according to
649 * the agreed parameters,
650 * 5) for MMAP memory type, allocates actual video memory, using the
651 * memory handling/allocation routines provided during queue initialization
653 * If req->count is 0, all the memory will be freed instead.
654 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
655 * and the queue is not busy, memory will be reallocated.
657 * The return values from this function are intended to be directly returned
658 * from vidioc_reqbufs handler in driver.
660 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
662 unsigned int num_buffers, allocated_buffers, num_planes = 0;
666 dprintk(1, "reqbufs: streaming active\n");
670 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
672 * We already have buffers allocated, so first check if they
673 * are not in use and can be freed.
675 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
676 dprintk(1, "reqbufs: memory in use, cannot free\n");
680 ret = __vb2_queue_free(q, q->num_buffers);
685 * In case of REQBUFS(0) return immediately without calling
686 * driver's queue_setup() callback and allocating resources.
693 * Make sure the requested values and current defaults are sane.
695 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
696 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
697 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
698 q->memory = req->memory;
701 * Ask the driver how many buffers and planes per buffer it requires.
702 * Driver also sets the size and allocator context for each plane.
704 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
705 q->plane_sizes, q->alloc_ctx);
709 /* Finally, allocate buffers and video memory */
710 ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
712 dprintk(1, "Memory allocation failed\n");
716 allocated_buffers = ret;
719 * Check if driver can handle the allocated number of buffers.
721 if (allocated_buffers < num_buffers) {
722 num_buffers = allocated_buffers;
724 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
725 &num_planes, q->plane_sizes, q->alloc_ctx);
727 if (!ret && allocated_buffers < num_buffers)
731 * Either the driver has accepted a smaller number of buffers,
732 * or .queue_setup() returned an error
736 q->num_buffers = allocated_buffers;
739 __vb2_queue_free(q, allocated_buffers);
744 * Return the number of successfully allocated buffers
747 req->count = allocated_buffers;
753 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
755 * @q: videobuf2 queue
756 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
758 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
760 int ret = __verify_memory_type(q, req->memory, req->type);
762 return ret ? ret : __reqbufs(q, req);
764 EXPORT_SYMBOL_GPL(vb2_reqbufs);
767 * __create_bufs() - Allocate buffers and any required auxiliary structs
768 * @q: videobuf2 queue
769 * @create: creation parameters, passed from userspace to vidioc_create_bufs
772 * Should be called from vidioc_create_bufs ioctl handler of a driver.
774 * 1) verifies parameter sanity
775 * 2) calls the .queue_setup() queue operation
776 * 3) performs any necessary memory allocations
778 * The return values from this function are intended to be directly returned
779 * from vidioc_create_bufs handler in driver.
781 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
783 unsigned int num_planes = 0, num_buffers, allocated_buffers;
786 if (q->num_buffers == VIDEO_MAX_FRAME) {
787 dprintk(1, "%s(): maximum number of buffers already allocated\n",
792 if (!q->num_buffers) {
793 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
794 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
795 q->memory = create->memory;
798 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
801 * Ask the driver, whether the requested number of buffers, planes per
802 * buffer and their sizes are acceptable
804 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
805 &num_planes, q->plane_sizes, q->alloc_ctx);
809 /* Finally, allocate buffers and video memory */
810 ret = __vb2_queue_alloc(q, create->memory, num_buffers,
813 dprintk(1, "Memory allocation failed\n");
817 allocated_buffers = ret;
820 * Check if driver can handle the so far allocated number of buffers.
822 if (ret < num_buffers) {
826 * q->num_buffers contains the total number of buffers, that the
827 * queue driver has set up
829 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
830 &num_planes, q->plane_sizes, q->alloc_ctx);
832 if (!ret && allocated_buffers < num_buffers)
836 * Either the driver has accepted a smaller number of buffers,
837 * or .queue_setup() returned an error
841 q->num_buffers += allocated_buffers;
844 __vb2_queue_free(q, allocated_buffers);
849 * Return the number of successfully allocated buffers
852 create->count = allocated_buffers;
858 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
859 * memory and type values.
860 * @q: videobuf2 queue
861 * @create: creation parameters, passed from userspace to vidioc_create_bufs
864 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
866 int ret = __verify_memory_type(q, create->memory, create->format.type);
868 create->index = q->num_buffers;
869 if (create->count == 0)
870 return ret != -EBUSY ? ret : 0;
871 return ret ? ret : __create_bufs(q, create);
873 EXPORT_SYMBOL_GPL(vb2_create_bufs);
876 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
877 * @vb: vb2_buffer to which the plane in question belongs to
878 * @plane_no: plane number for which the address is to be returned
880 * This function returns a kernel virtual address of a given plane if
881 * such a mapping exist, NULL otherwise.
883 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
885 struct vb2_queue *q = vb->vb2_queue;
887 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
890 return call_memop(q, vaddr, vb->planes[plane_no].mem_priv);
893 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
896 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
897 * @vb: vb2_buffer to which the plane in question belongs to
898 * @plane_no: plane number for which the cookie is to be returned
900 * This function returns an allocator specific cookie for a given plane if
901 * available, NULL otherwise. The allocator should provide some simple static
902 * inline function, which would convert this cookie to the allocator specific
903 * type that can be used directly by the driver to access the buffer. This can
904 * be for example physical address, pointer to scatter list or IOMMU mapping.
906 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
908 struct vb2_queue *q = vb->vb2_queue;
910 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
913 return call_memop(q, cookie, vb->planes[plane_no].mem_priv);
915 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
918 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
919 * @vb: vb2_buffer returned from the driver
920 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
921 * or VB2_BUF_STATE_ERROR if the operation finished with an error
923 * This function should be called by the driver after a hardware operation on
924 * a buffer is finished and the buffer may be returned to userspace. The driver
925 * cannot use this buffer anymore until it is queued back to it by videobuf
926 * by the means of buf_queue callback. Only buffers previously queued to the
927 * driver by buf_queue can be passed to this function.
929 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
931 struct vb2_queue *q = vb->vb2_queue;
935 if (vb->state != VB2_BUF_STATE_ACTIVE)
938 if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
941 dprintk(4, "Done processing on buffer %d, state: %d\n",
942 vb->v4l2_buf.index, state);
945 for (plane = 0; plane < vb->num_planes; ++plane)
946 call_memop(q, finish, vb->planes[plane].mem_priv);
948 /* Add the buffer to the done buffers list */
949 spin_lock_irqsave(&q->done_lock, flags);
951 list_add_tail(&vb->done_entry, &q->done_list);
952 atomic_dec(&q->queued_count);
953 spin_unlock_irqrestore(&q->done_lock, flags);
955 /* Inform any processes that may be waiting for buffers */
956 wake_up(&q->done_wq);
958 EXPORT_SYMBOL_GPL(vb2_buffer_done);
961 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
962 * v4l2_buffer by the userspace. The caller has already verified that struct
963 * v4l2_buffer has a valid number of planes.
965 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
966 struct v4l2_plane *v4l2_planes)
970 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
971 /* Fill in driver-provided information for OUTPUT types */
972 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
974 * Will have to go up to b->length when API starts
975 * accepting variable number of planes.
977 for (plane = 0; plane < vb->num_planes; ++plane) {
978 v4l2_planes[plane].bytesused =
979 b->m.planes[plane].bytesused;
980 v4l2_planes[plane].data_offset =
981 b->m.planes[plane].data_offset;
985 if (b->memory == V4L2_MEMORY_USERPTR) {
986 for (plane = 0; plane < vb->num_planes; ++plane) {
987 v4l2_planes[plane].m.userptr =
988 b->m.planes[plane].m.userptr;
989 v4l2_planes[plane].length =
990 b->m.planes[plane].length;
993 if (b->memory == V4L2_MEMORY_DMABUF) {
994 for (plane = 0; plane < vb->num_planes; ++plane) {
995 v4l2_planes[plane].m.fd =
996 b->m.planes[plane].m.fd;
997 v4l2_planes[plane].length =
998 b->m.planes[plane].length;
999 v4l2_planes[plane].data_offset =
1000 b->m.planes[plane].data_offset;
1005 * Single-planar buffers do not use planes array,
1006 * so fill in relevant v4l2_buffer struct fields instead.
1007 * In videobuf we use our internal V4l2_planes struct for
1008 * single-planar buffers as well, for simplicity.
1010 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
1011 v4l2_planes[0].bytesused = b->bytesused;
1012 v4l2_planes[0].data_offset = 0;
1015 if (b->memory == V4L2_MEMORY_USERPTR) {
1016 v4l2_planes[0].m.userptr = b->m.userptr;
1017 v4l2_planes[0].length = b->length;
1020 if (b->memory == V4L2_MEMORY_DMABUF) {
1021 v4l2_planes[0].m.fd = b->m.fd;
1022 v4l2_planes[0].length = b->length;
1023 v4l2_planes[0].data_offset = 0;
1028 vb->v4l2_buf.field = b->field;
1029 vb->v4l2_buf.timestamp = b->timestamp;
1030 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
1034 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
1036 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1038 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1039 struct vb2_queue *q = vb->vb2_queue;
1043 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1045 /* Copy relevant information provided by the userspace */
1046 __fill_vb2_buffer(vb, b, planes);
1048 for (plane = 0; plane < vb->num_planes; ++plane) {
1049 /* Skip the plane if already verified */
1050 if (vb->v4l2_planes[plane].m.userptr &&
1051 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1052 && vb->v4l2_planes[plane].length == planes[plane].length)
1055 dprintk(3, "qbuf: userspace address for plane %d changed, "
1056 "reacquiring memory\n", plane);
1058 /* Check if the provided plane buffer is large enough */
1059 if (planes[plane].length < q->plane_sizes[plane]) {
1060 dprintk(1, "qbuf: provided buffer size %u is less than "
1061 "setup size %u for plane %d\n",
1062 planes[plane].length,
1063 q->plane_sizes[plane], plane);
1068 /* Release previously acquired memory if present */
1069 if (vb->planes[plane].mem_priv)
1070 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1072 vb->planes[plane].mem_priv = NULL;
1073 vb->v4l2_planes[plane].m.userptr = 0;
1074 vb->v4l2_planes[plane].length = 0;
1076 /* Acquire each plane's memory */
1077 mem_priv = call_memop(q, get_userptr, q->alloc_ctx[plane],
1078 planes[plane].m.userptr,
1079 planes[plane].length, write);
1080 if (IS_ERR_OR_NULL(mem_priv)) {
1081 dprintk(1, "qbuf: failed acquiring userspace "
1082 "memory for plane %d\n", plane);
1083 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1086 vb->planes[plane].mem_priv = mem_priv;
1090 * Call driver-specific initialization on the newly acquired buffer,
1093 ret = call_qop(q, buf_init, vb);
1095 dprintk(1, "qbuf: buffer initialization failed\n");
1100 * Now that everything is in order, copy relevant information
1101 * provided by userspace.
1103 for (plane = 0; plane < vb->num_planes; ++plane)
1104 vb->v4l2_planes[plane] = planes[plane];
1108 /* In case of errors, release planes that were already acquired */
1109 for (plane = 0; plane < vb->num_planes; ++plane) {
1110 if (vb->planes[plane].mem_priv)
1111 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1112 vb->planes[plane].mem_priv = NULL;
1113 vb->v4l2_planes[plane].m.userptr = 0;
1114 vb->v4l2_planes[plane].length = 0;
1121 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1123 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1125 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1130 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1132 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1134 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1135 struct vb2_queue *q = vb->vb2_queue;
1139 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1141 /* Verify and copy relevant information provided by the userspace */
1142 __fill_vb2_buffer(vb, b, planes);
1144 for (plane = 0; plane < vb->num_planes; ++plane) {
1145 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1147 if (IS_ERR_OR_NULL(dbuf)) {
1148 dprintk(1, "qbuf: invalid dmabuf fd for plane %d\n",
1154 /* use DMABUF size if length is not provided */
1155 if (planes[plane].length == 0)
1156 planes[plane].length = dbuf->size;
1158 if (planes[plane].length < planes[plane].data_offset +
1159 q->plane_sizes[plane]) {
1160 dprintk(1, "qbuf: invalid dmabuf length for plane %d\n",
1166 /* Skip the plane if already verified */
1167 if (dbuf == vb->planes[plane].dbuf &&
1168 vb->v4l2_planes[plane].length == planes[plane].length) {
1173 dprintk(1, "qbuf: buffer for plane %d changed\n", plane);
1175 /* Release previously acquired memory if present */
1176 __vb2_plane_dmabuf_put(q, &vb->planes[plane]);
1177 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1179 /* Acquire each plane's memory */
1180 mem_priv = call_memop(q, attach_dmabuf, q->alloc_ctx[plane],
1181 dbuf, planes[plane].length, write);
1182 if (IS_ERR(mem_priv)) {
1183 dprintk(1, "qbuf: failed to attach dmabuf\n");
1184 ret = PTR_ERR(mem_priv);
1189 vb->planes[plane].dbuf = dbuf;
1190 vb->planes[plane].mem_priv = mem_priv;
1193 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1194 * really we want to do this just before the DMA, not while queueing
1197 for (plane = 0; plane < vb->num_planes; ++plane) {
1198 ret = call_memop(q, map_dmabuf, vb->planes[plane].mem_priv);
1200 dprintk(1, "qbuf: failed to map dmabuf for plane %d\n",
1204 vb->planes[plane].dbuf_mapped = 1;
1208 * Call driver-specific initialization on the newly acquired buffer,
1211 ret = call_qop(q, buf_init, vb);
1213 dprintk(1, "qbuf: buffer initialization failed\n");
1218 * Now that everything is in order, copy relevant information
1219 * provided by userspace.
1221 for (plane = 0; plane < vb->num_planes; ++plane)
1222 vb->v4l2_planes[plane] = planes[plane];
1226 /* In case of errors, release planes that were already acquired */
1227 __vb2_buf_dmabuf_put(vb);
1233 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1235 static void __enqueue_in_driver(struct vb2_buffer *vb)
1237 struct vb2_queue *q = vb->vb2_queue;
1240 vb->state = VB2_BUF_STATE_ACTIVE;
1241 atomic_inc(&q->queued_count);
1244 for (plane = 0; plane < vb->num_planes; ++plane)
1245 call_memop(q, prepare, vb->planes[plane].mem_priv);
1247 q->ops->buf_queue(vb);
1250 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1252 struct vb2_queue *q = vb->vb2_queue;
1253 struct rw_semaphore *mmap_sem;
1256 ret = __verify_length(vb, b);
1258 dprintk(1, "%s(): plane parameters verification failed: %d\n",
1263 vb->state = VB2_BUF_STATE_PREPARING;
1264 switch (q->memory) {
1265 case V4L2_MEMORY_MMAP:
1266 ret = __qbuf_mmap(vb, b);
1268 case V4L2_MEMORY_USERPTR:
1270 * In case of user pointer buffers vb2 allocators need to get
1271 * direct access to userspace pages. This requires getting
1272 * the mmap semaphore for read access in the current process
1273 * structure. The same semaphore is taken before calling mmap
1274 * operation, while both qbuf/prepare_buf and mmap are called
1275 * by the driver or v4l2 core with the driver's lock held.
1276 * To avoid an AB-BA deadlock (mmap_sem then driver's lock in
1277 * mmap and driver's lock then mmap_sem in qbuf/prepare_buf),
1278 * the videobuf2 core releases the driver's lock, takes
1279 * mmap_sem and then takes the driver's lock again.
1281 mmap_sem = ¤t->mm->mmap_sem;
1282 call_qop(q, wait_prepare, q);
1283 down_read(mmap_sem);
1284 call_qop(q, wait_finish, q);
1286 ret = __qbuf_userptr(vb, b);
1290 case V4L2_MEMORY_DMABUF:
1291 ret = __qbuf_dmabuf(vb, b);
1294 WARN(1, "Invalid queue type\n");
1299 ret = call_qop(q, buf_prepare, vb);
1301 dprintk(1, "qbuf: buffer preparation failed: %d\n", ret);
1302 vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED;
1307 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1311 dprintk(1, "%s(): file io in progress\n", opname);
1315 if (b->type != q->type) {
1316 dprintk(1, "%s(): invalid buffer type\n", opname);
1320 if (b->index >= q->num_buffers) {
1321 dprintk(1, "%s(): buffer index out of range\n", opname);
1325 if (q->bufs[b->index] == NULL) {
1326 /* Should never happen */
1327 dprintk(1, "%s(): buffer is NULL\n", opname);
1331 if (b->memory != q->memory) {
1332 dprintk(1, "%s(): invalid memory type\n", opname);
1336 return __verify_planes_array(q->bufs[b->index], b);
1340 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1341 * @q: videobuf2 queue
1342 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1345 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1347 * 1) verifies the passed buffer,
1348 * 2) calls buf_prepare callback in the driver (if provided), in which
1349 * driver-specific buffer initialization can be performed,
1351 * The return values from this function are intended to be directly returned
1352 * from vidioc_prepare_buf handler in driver.
1354 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1356 int ret = vb2_queue_or_prepare_buf(q, b, "prepare_buf");
1357 struct vb2_buffer *vb;
1362 vb = q->bufs[b->index];
1363 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1364 dprintk(1, "%s(): invalid buffer state %d\n", __func__,
1369 ret = __buf_prepare(vb, b);
1371 /* Fill buffer information for the userspace */
1372 __fill_v4l2_buffer(vb, b);
1374 dprintk(1, "%s() of buffer %d succeeded\n", __func__, vb->v4l2_buf.index);
1378 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1381 * vb2_qbuf() - Queue a buffer from userspace
1382 * @q: videobuf2 queue
1383 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1386 * Should be called from vidioc_qbuf ioctl handler of a driver.
1388 * 1) verifies the passed buffer,
1389 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1390 * which driver-specific buffer initialization can be performed,
1391 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1392 * callback for processing.
1394 * The return values from this function are intended to be directly returned
1395 * from vidioc_qbuf handler in driver.
1397 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1399 int ret = vb2_queue_or_prepare_buf(q, b, "qbuf");
1400 struct vb2_buffer *vb;
1405 vb = q->bufs[b->index];
1406 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1407 dprintk(1, "%s(): invalid buffer state %d\n", __func__,
1412 switch (vb->state) {
1413 case VB2_BUF_STATE_DEQUEUED:
1414 ret = __buf_prepare(vb, b);
1418 case VB2_BUF_STATE_PREPARED:
1420 case VB2_BUF_STATE_PREPARING:
1421 dprintk(1, "qbuf: buffer still being prepared\n");
1424 dprintk(1, "qbuf: buffer already in use\n");
1429 * Add to the queued buffers list, a buffer will stay on it until
1430 * dequeued in dqbuf.
1432 list_add_tail(&vb->queued_entry, &q->queued_list);
1433 vb->state = VB2_BUF_STATE_QUEUED;
1436 * If already streaming, give the buffer to driver for processing.
1437 * If not, the buffer will be given to driver on next streamon.
1440 __enqueue_in_driver(vb);
1442 /* Fill buffer information for the userspace */
1443 __fill_v4l2_buffer(vb, b);
1445 dprintk(1, "%s() of buffer %d succeeded\n", __func__, vb->v4l2_buf.index);
1448 EXPORT_SYMBOL_GPL(vb2_qbuf);
1451 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1454 * Will sleep if required for nonblocking == false.
1456 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1459 * All operations on vb_done_list are performed under done_lock
1460 * spinlock protection. However, buffers may be removed from
1461 * it and returned to userspace only while holding both driver's
1462 * lock and the done_lock spinlock. Thus we can be sure that as
1463 * long as we hold the driver's lock, the list will remain not
1464 * empty if list_empty() check succeeds.
1470 if (!q->streaming) {
1471 dprintk(1, "Streaming off, will not wait for buffers\n");
1475 if (!list_empty(&q->done_list)) {
1477 * Found a buffer that we were waiting for.
1483 dprintk(1, "Nonblocking and no buffers to dequeue, "
1489 * We are streaming and blocking, wait for another buffer to
1490 * become ready or for streamoff. Driver's lock is released to
1491 * allow streamoff or qbuf to be called while waiting.
1493 call_qop(q, wait_prepare, q);
1496 * All locks have been released, it is safe to sleep now.
1498 dprintk(3, "Will sleep waiting for buffers\n");
1499 ret = wait_event_interruptible(q->done_wq,
1500 !list_empty(&q->done_list) || !q->streaming);
1503 * We need to reevaluate both conditions again after reacquiring
1504 * the locks or return an error if one occurred.
1506 call_qop(q, wait_finish, q);
1508 dprintk(1, "Sleep was interrupted\n");
1516 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1518 * Will sleep if required for nonblocking == false.
1520 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1521 struct v4l2_buffer *b, int nonblocking)
1523 unsigned long flags;
1527 * Wait for at least one buffer to become available on the done_list.
1529 ret = __vb2_wait_for_done_vb(q, nonblocking);
1534 * Driver's lock has been held since we last verified that done_list
1535 * is not empty, so no need for another list_empty(done_list) check.
1537 spin_lock_irqsave(&q->done_lock, flags);
1538 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1540 * Only remove the buffer from done_list if v4l2_buffer can handle all
1543 ret = __verify_planes_array(*vb, b);
1545 list_del(&(*vb)->done_entry);
1546 spin_unlock_irqrestore(&q->done_lock, flags);
1552 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1553 * @q: videobuf2 queue
1555 * This function will wait until all buffers that have been given to the driver
1556 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1557 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1558 * taken, for example from stop_streaming() callback.
1560 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1562 if (!q->streaming) {
1563 dprintk(1, "Streaming off, will not wait for buffers\n");
1567 wait_event(q->done_wq, !atomic_read(&q->queued_count));
1570 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1573 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1575 static void __vb2_dqbuf(struct vb2_buffer *vb)
1577 struct vb2_queue *q = vb->vb2_queue;
1580 /* nothing to do if the buffer is already dequeued */
1581 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1584 vb->state = VB2_BUF_STATE_DEQUEUED;
1586 /* unmap DMABUF buffer */
1587 if (q->memory == V4L2_MEMORY_DMABUF)
1588 for (i = 0; i < vb->num_planes; ++i) {
1589 if (!vb->planes[i].dbuf_mapped)
1591 call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv);
1592 vb->planes[i].dbuf_mapped = 0;
1597 * vb2_dqbuf() - Dequeue a buffer to the userspace
1598 * @q: videobuf2 queue
1599 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
1601 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1602 * buffers ready for dequeuing are present. Normally the driver
1603 * would be passing (file->f_flags & O_NONBLOCK) here
1605 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1607 * 1) verifies the passed buffer,
1608 * 2) calls buf_finish callback in the driver (if provided), in which
1609 * driver can perform any additional operations that may be required before
1610 * returning the buffer to userspace, such as cache sync,
1611 * 3) the buffer struct members are filled with relevant information for
1614 * The return values from this function are intended to be directly returned
1615 * from vidioc_dqbuf handler in driver.
1617 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
1619 struct vb2_buffer *vb = NULL;
1623 dprintk(1, "dqbuf: file io in progress\n");
1627 if (b->type != q->type) {
1628 dprintk(1, "dqbuf: invalid buffer type\n");
1631 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
1635 ret = call_qop(q, buf_finish, vb);
1637 dprintk(1, "dqbuf: buffer finish failed\n");
1641 switch (vb->state) {
1642 case VB2_BUF_STATE_DONE:
1643 dprintk(3, "dqbuf: Returning done buffer\n");
1645 case VB2_BUF_STATE_ERROR:
1646 dprintk(3, "dqbuf: Returning done buffer with errors\n");
1649 dprintk(1, "dqbuf: Invalid buffer state\n");
1653 /* Fill buffer information for the userspace */
1654 __fill_v4l2_buffer(vb, b);
1655 /* Remove from videobuf queue */
1656 list_del(&vb->queued_entry);
1657 /* go back to dequeued state */
1660 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1661 vb->v4l2_buf.index, vb->state);
1665 EXPORT_SYMBOL_GPL(vb2_dqbuf);
1668 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1670 * Removes all queued buffers from driver's queue and all buffers queued by
1671 * userspace from videobuf's queue. Returns to state after reqbufs.
1673 static void __vb2_queue_cancel(struct vb2_queue *q)
1678 * Tell driver to stop all transactions and release all queued
1682 call_qop(q, stop_streaming, q);
1686 * Remove all buffers from videobuf's list...
1688 INIT_LIST_HEAD(&q->queued_list);
1690 * ...and done list; userspace will not receive any buffers it
1691 * has not already dequeued before initiating cancel.
1693 INIT_LIST_HEAD(&q->done_list);
1694 atomic_set(&q->queued_count, 0);
1695 wake_up_all(&q->done_wq);
1698 * Reinitialize all buffers for next use.
1700 for (i = 0; i < q->num_buffers; ++i)
1701 __vb2_dqbuf(q->bufs[i]);
1705 * vb2_streamon - start streaming
1706 * @q: videobuf2 queue
1707 * @type: type argument passed from userspace to vidioc_streamon handler
1709 * Should be called from vidioc_streamon handler of a driver.
1711 * 1) verifies current state
1712 * 2) passes any previously queued buffers to the driver and starts streaming
1714 * The return values from this function are intended to be directly returned
1715 * from vidioc_streamon handler in the driver.
1717 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
1719 struct vb2_buffer *vb;
1723 dprintk(1, "streamon: file io in progress\n");
1727 if (type != q->type) {
1728 dprintk(1, "streamon: invalid stream type\n");
1733 dprintk(3, "streamon successful: already streaming\n");
1738 * If any buffers were queued before streamon,
1739 * we can now pass them to driver for processing.
1741 list_for_each_entry(vb, &q->queued_list, queued_entry)
1742 __enqueue_in_driver(vb);
1745 * Let driver notice that streaming state has been enabled.
1747 ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
1749 dprintk(1, "streamon: driver refused to start streaming\n");
1750 __vb2_queue_cancel(q);
1756 dprintk(3, "Streamon successful\n");
1759 EXPORT_SYMBOL_GPL(vb2_streamon);
1763 * vb2_streamoff - stop streaming
1764 * @q: videobuf2 queue
1765 * @type: type argument passed from userspace to vidioc_streamoff handler
1767 * Should be called from vidioc_streamoff handler of a driver.
1769 * 1) verifies current state,
1770 * 2) stop streaming and dequeues any queued buffers, including those previously
1771 * passed to the driver (after waiting for the driver to finish).
1773 * This call can be used for pausing playback.
1774 * The return values from this function are intended to be directly returned
1775 * from vidioc_streamoff handler in the driver
1777 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
1780 dprintk(1, "streamoff: file io in progress\n");
1784 if (type != q->type) {
1785 dprintk(1, "streamoff: invalid stream type\n");
1789 if (!q->streaming) {
1790 dprintk(3, "streamoff successful: not streaming\n");
1795 * Cancel will pause streaming and remove all buffers from the driver
1796 * and videobuf, effectively returning control over them to userspace.
1798 __vb2_queue_cancel(q);
1800 dprintk(3, "Streamoff successful\n");
1803 EXPORT_SYMBOL_GPL(vb2_streamoff);
1806 * __find_plane_by_offset() - find plane associated with the given offset off
1808 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1809 unsigned int *_buffer, unsigned int *_plane)
1811 struct vb2_buffer *vb;
1812 unsigned int buffer, plane;
1815 * Go over all buffers and their planes, comparing the given offset
1816 * with an offset assigned to each plane. If a match is found,
1817 * return its buffer and plane numbers.
1819 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1820 vb = q->bufs[buffer];
1822 for (plane = 0; plane < vb->num_planes; ++plane) {
1823 if (vb->v4l2_planes[plane].m.mem_offset == off) {
1835 * vb2_expbuf() - Export a buffer as a file descriptor
1836 * @q: videobuf2 queue
1837 * @eb: export buffer structure passed from userspace to vidioc_expbuf
1840 * The return values from this function are intended to be directly returned
1841 * from vidioc_expbuf handler in driver.
1843 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
1845 struct vb2_buffer *vb = NULL;
1846 struct vb2_plane *vb_plane;
1848 struct dma_buf *dbuf;
1850 if (q->memory != V4L2_MEMORY_MMAP) {
1851 dprintk(1, "Queue is not currently set up for mmap\n");
1855 if (!q->mem_ops->get_dmabuf) {
1856 dprintk(1, "Queue does not support DMA buffer exporting\n");
1860 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
1861 dprintk(1, "Queue does support only O_CLOEXEC and access mode flags\n");
1865 if (eb->type != q->type) {
1866 dprintk(1, "qbuf: invalid buffer type\n");
1870 if (eb->index >= q->num_buffers) {
1871 dprintk(1, "buffer index out of range\n");
1875 vb = q->bufs[eb->index];
1877 if (eb->plane >= vb->num_planes) {
1878 dprintk(1, "buffer plane out of range\n");
1882 vb_plane = &vb->planes[eb->plane];
1884 dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
1885 if (IS_ERR_OR_NULL(dbuf)) {
1886 dprintk(1, "Failed to export buffer %d, plane %d\n",
1887 eb->index, eb->plane);
1891 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
1893 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1894 eb->index, eb->plane, ret);
1899 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1900 eb->index, eb->plane, ret);
1905 EXPORT_SYMBOL_GPL(vb2_expbuf);
1908 * vb2_mmap() - map video buffers into application address space
1909 * @q: videobuf2 queue
1910 * @vma: vma passed to the mmap file operation handler in the driver
1912 * Should be called from mmap file operation handler of a driver.
1913 * This function maps one plane of one of the available video buffers to
1914 * userspace. To map whole video memory allocated on reqbufs, this function
1915 * has to be called once per each plane per each buffer previously allocated.
1917 * When the userspace application calls mmap, it passes to it an offset returned
1918 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
1919 * a "cookie", which is then used to identify the plane to be mapped.
1920 * This function finds a plane with a matching offset and a mapping is performed
1921 * by the means of a provided memory operation.
1923 * The return values from this function are intended to be directly returned
1924 * from the mmap handler in driver.
1926 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1928 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1929 struct vb2_buffer *vb;
1930 unsigned int buffer, plane;
1932 unsigned long length;
1934 if (q->memory != V4L2_MEMORY_MMAP) {
1935 dprintk(1, "Queue is not currently set up for mmap\n");
1940 * Check memory area access mode.
1942 if (!(vma->vm_flags & VM_SHARED)) {
1943 dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
1946 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1947 if (!(vma->vm_flags & VM_WRITE)) {
1948 dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
1952 if (!(vma->vm_flags & VM_READ)) {
1953 dprintk(1, "Invalid vma flags, VM_READ needed\n");
1959 * Find the plane corresponding to the offset passed by userspace.
1961 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1965 vb = q->bufs[buffer];
1968 * MMAP requires page_aligned buffers.
1969 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1970 * so, we need to do the same here.
1972 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
1973 if (length < (vma->vm_end - vma->vm_start)) {
1975 "MMAP invalid, as it would overflow buffer length\n");
1979 ret = call_memop(q, mmap, vb->planes[plane].mem_priv, vma);
1983 dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
1986 EXPORT_SYMBOL_GPL(vb2_mmap);
1989 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1992 unsigned long pgoff,
1993 unsigned long flags)
1995 unsigned long off = pgoff << PAGE_SHIFT;
1996 struct vb2_buffer *vb;
1997 unsigned int buffer, plane;
2000 if (q->memory != V4L2_MEMORY_MMAP) {
2001 dprintk(1, "Queue is not currently set up for mmap\n");
2006 * Find the plane corresponding to the offset passed by userspace.
2008 ret = __find_plane_by_offset(q, off, &buffer, &plane);
2012 vb = q->bufs[buffer];
2014 return (unsigned long)vb2_plane_vaddr(vb, plane);
2016 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
2019 static int __vb2_init_fileio(struct vb2_queue *q, int read);
2020 static int __vb2_cleanup_fileio(struct vb2_queue *q);
2023 * vb2_poll() - implements poll userspace operation
2024 * @q: videobuf2 queue
2025 * @file: file argument passed to the poll file operation handler
2026 * @wait: wait argument passed to the poll file operation handler
2028 * This function implements poll file operation handler for a driver.
2029 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
2030 * be informed that the file descriptor of a video device is available for
2032 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2033 * will be reported as available for writing.
2035 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2038 * The return values from this function are intended to be directly returned
2039 * from poll handler in driver.
2041 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2043 struct video_device *vfd = video_devdata(file);
2044 unsigned long req_events = poll_requested_events(wait);
2045 struct vb2_buffer *vb = NULL;
2046 unsigned int res = 0;
2047 unsigned long flags;
2049 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2050 struct v4l2_fh *fh = file->private_data;
2052 if (v4l2_event_pending(fh))
2054 else if (req_events & POLLPRI)
2055 poll_wait(file, &fh->wait, wait);
2058 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2060 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2064 * Start file I/O emulator only if streaming API has not been used yet.
2066 if (q->num_buffers == 0 && q->fileio == NULL) {
2067 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2068 (req_events & (POLLIN | POLLRDNORM))) {
2069 if (__vb2_init_fileio(q, 1))
2070 return res | POLLERR;
2072 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2073 (req_events & (POLLOUT | POLLWRNORM))) {
2074 if (__vb2_init_fileio(q, 0))
2075 return res | POLLERR;
2077 * Write to OUTPUT queue can be done immediately.
2079 return res | POLLOUT | POLLWRNORM;
2084 * There is nothing to wait for if no buffers have already been queued.
2086 if (list_empty(&q->queued_list))
2087 return res | POLLERR;
2089 if (list_empty(&q->done_list))
2090 poll_wait(file, &q->done_wq, wait);
2093 * Take first buffer available for dequeuing.
2095 spin_lock_irqsave(&q->done_lock, flags);
2096 if (!list_empty(&q->done_list))
2097 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2099 spin_unlock_irqrestore(&q->done_lock, flags);
2101 if (vb && (vb->state == VB2_BUF_STATE_DONE
2102 || vb->state == VB2_BUF_STATE_ERROR)) {
2103 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2104 res | POLLOUT | POLLWRNORM :
2105 res | POLLIN | POLLRDNORM;
2109 EXPORT_SYMBOL_GPL(vb2_poll);
2112 * vb2_queue_init() - initialize a videobuf2 queue
2113 * @q: videobuf2 queue; this structure should be allocated in driver
2115 * The vb2_queue structure should be allocated by the driver. The driver is
2116 * responsible of clearing it's content and setting initial values for some
2117 * required entries before calling this function.
2118 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2119 * to the struct vb2_queue description in include/media/videobuf2-core.h
2120 * for more information.
2122 int vb2_queue_init(struct vb2_queue *q)
2129 WARN_ON(!q->mem_ops) ||
2130 WARN_ON(!q->type) ||
2131 WARN_ON(!q->io_modes) ||
2132 WARN_ON(!q->ops->queue_setup) ||
2133 WARN_ON(!q->ops->buf_queue) ||
2134 WARN_ON(q->timestamp_type & ~V4L2_BUF_FLAG_TIMESTAMP_MASK))
2137 /* Warn that the driver should choose an appropriate timestamp type */
2138 WARN_ON(q->timestamp_type == V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2140 INIT_LIST_HEAD(&q->queued_list);
2141 INIT_LIST_HEAD(&q->done_list);
2142 spin_lock_init(&q->done_lock);
2143 init_waitqueue_head(&q->done_wq);
2145 if (q->buf_struct_size == 0)
2146 q->buf_struct_size = sizeof(struct vb2_buffer);
2150 EXPORT_SYMBOL_GPL(vb2_queue_init);
2153 * vb2_queue_release() - stop streaming, release the queue and free memory
2154 * @q: videobuf2 queue
2156 * This function stops streaming and performs necessary clean ups, including
2157 * freeing video buffer memory. The driver is responsible for freeing
2158 * the vb2_queue structure itself.
2160 void vb2_queue_release(struct vb2_queue *q)
2162 __vb2_cleanup_fileio(q);
2163 __vb2_queue_cancel(q);
2164 __vb2_queue_free(q, q->num_buffers);
2166 EXPORT_SYMBOL_GPL(vb2_queue_release);
2169 * struct vb2_fileio_buf - buffer context used by file io emulator
2171 * vb2 provides a compatibility layer and emulator of file io (read and
2172 * write) calls on top of streaming API. This structure is used for
2173 * tracking context related to the buffers.
2175 struct vb2_fileio_buf {
2179 unsigned int queued:1;
2183 * struct vb2_fileio_data - queue context used by file io emulator
2185 * vb2 provides a compatibility layer and emulator of file io (read and
2186 * write) calls on top of streaming API. For proper operation it required
2187 * this structure to save the driver state between each call of the read
2188 * or write function.
2190 struct vb2_fileio_data {
2191 struct v4l2_requestbuffers req;
2192 struct v4l2_buffer b;
2193 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2195 unsigned int q_count;
2196 unsigned int dq_count;
2201 * __vb2_init_fileio() - initialize file io emulator
2202 * @q: videobuf2 queue
2203 * @read: mode selector (1 means read, 0 means write)
2205 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2207 struct vb2_fileio_data *fileio;
2209 unsigned int count = 0;
2214 if ((read && !(q->io_modes & VB2_READ)) ||
2215 (!read && !(q->io_modes & VB2_WRITE)))
2219 * Check if device supports mapping buffers to kernel virtual space.
2221 if (!q->mem_ops->vaddr)
2225 * Check if streaming api has not been already activated.
2227 if (q->streaming || q->num_buffers > 0)
2231 * Start with count 1, driver can increase it in queue_setup()
2235 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2236 (read) ? "read" : "write", count, q->io_flags);
2238 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2242 fileio->flags = q->io_flags;
2245 * Request buffers and use MMAP type to force driver
2246 * to allocate buffers by itself.
2248 fileio->req.count = count;
2249 fileio->req.memory = V4L2_MEMORY_MMAP;
2250 fileio->req.type = q->type;
2251 ret = vb2_reqbufs(q, &fileio->req);
2256 * Check if plane_count is correct
2257 * (multiplane buffers are not supported).
2259 if (q->bufs[0]->num_planes != 1) {
2265 * Get kernel address of each buffer.
2267 for (i = 0; i < q->num_buffers; i++) {
2268 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2269 if (fileio->bufs[i].vaddr == NULL) {
2273 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2277 * Read mode requires pre queuing of all buffers.
2281 * Queue all buffers.
2283 for (i = 0; i < q->num_buffers; i++) {
2284 struct v4l2_buffer *b = &fileio->b;
2285 memset(b, 0, sizeof(*b));
2287 b->memory = q->memory;
2289 ret = vb2_qbuf(q, b);
2292 fileio->bufs[i].queued = 1;
2298 ret = vb2_streamon(q, q->type);
2308 fileio->req.count = 0;
2309 vb2_reqbufs(q, &fileio->req);
2317 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2318 * @q: videobuf2 queue
2320 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2322 struct vb2_fileio_data *fileio = q->fileio;
2326 * Hack fileio context to enable direct calls to vb2 ioctl
2331 vb2_streamoff(q, q->type);
2332 fileio->req.count = 0;
2333 vb2_reqbufs(q, &fileio->req);
2335 dprintk(3, "file io emulator closed\n");
2341 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2342 * @q: videobuf2 queue
2343 * @data: pointed to target userspace buffer
2344 * @count: number of bytes to read or write
2345 * @ppos: file handle position tracking pointer
2346 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2347 * @read: access mode selector (1 means read, 0 means write)
2349 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2350 loff_t *ppos, int nonblock, int read)
2352 struct vb2_fileio_data *fileio;
2353 struct vb2_fileio_buf *buf;
2356 dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
2357 read ? "read" : "write", (long)*ppos, count,
2358 nonblock ? "non" : "");
2364 * Initialize emulator on first call.
2367 ret = __vb2_init_fileio(q, read);
2368 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2375 * Hack fileio context to enable direct calls to vb2 ioctl interface.
2376 * The pointer will be restored before returning from this function.
2380 index = fileio->index;
2381 buf = &fileio->bufs[index];
2384 * Check if we need to dequeue the buffer.
2387 struct vb2_buffer *vb;
2390 * Call vb2_dqbuf to get buffer back.
2392 memset(&fileio->b, 0, sizeof(fileio->b));
2393 fileio->b.type = q->type;
2394 fileio->b.memory = q->memory;
2395 fileio->b.index = index;
2396 ret = vb2_dqbuf(q, &fileio->b, nonblock);
2397 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2400 fileio->dq_count += 1;
2403 * Get number of bytes filled by the driver
2405 vb = q->bufs[index];
2406 buf->size = vb2_get_plane_payload(vb, 0);
2411 * Limit count on last few bytes of the buffer.
2413 if (buf->pos + count > buf->size) {
2414 count = buf->size - buf->pos;
2415 dprintk(5, "reducing read count: %zd\n", count);
2419 * Transfer data to userspace.
2421 dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n",
2422 count, index, buf->pos);
2424 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2426 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2428 dprintk(3, "file io: error copying data\n");
2440 * Queue next buffer if required.
2442 if (buf->pos == buf->size ||
2443 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
2445 * Check if this is the last buffer to read.
2447 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
2448 fileio->dq_count == 1) {
2449 dprintk(3, "file io: read limit reached\n");
2451 * Restore fileio pointer and release the context.
2454 return __vb2_cleanup_fileio(q);
2458 * Call vb2_qbuf and give buffer to the driver.
2460 memset(&fileio->b, 0, sizeof(fileio->b));
2461 fileio->b.type = q->type;
2462 fileio->b.memory = q->memory;
2463 fileio->b.index = index;
2464 fileio->b.bytesused = buf->pos;
2465 ret = vb2_qbuf(q, &fileio->b);
2466 dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
2471 * Buffer has been queued, update the status
2475 buf->size = q->bufs[0]->v4l2_planes[0].length;
2476 fileio->q_count += 1;
2479 * Switch to the next buffer
2481 fileio->index = (index + 1) % q->num_buffers;
2484 * Start streaming if required.
2486 if (!read && !q->streaming) {
2487 ret = vb2_streamon(q, q->type);
2494 * Return proper number of bytes processed.
2500 * Restore the fileio context and block vb2 ioctl interface.
2506 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2507 loff_t *ppos, int nonblocking)
2509 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2511 EXPORT_SYMBOL_GPL(vb2_read);
2513 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2514 loff_t *ppos, int nonblocking)
2516 return __vb2_perform_fileio(q, (char __user *) data, count,
2517 ppos, nonblocking, 0);
2519 EXPORT_SYMBOL_GPL(vb2_write);
2523 * The following functions are not part of the vb2 core API, but are helper
2524 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
2525 * and struct vb2_ops.
2526 * They contain boilerplate code that most if not all drivers have to do
2527 * and so they simplify the driver code.
2530 /* The queue is busy if there is a owner and you are not that owner. */
2531 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
2533 return vdev->queue->owner && vdev->queue->owner != file->private_data;
2536 /* vb2 ioctl helpers */
2538 int vb2_ioctl_reqbufs(struct file *file, void *priv,
2539 struct v4l2_requestbuffers *p)
2541 struct video_device *vdev = video_devdata(file);
2542 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
2546 if (vb2_queue_is_busy(vdev, file))
2548 res = __reqbufs(vdev->queue, p);
2549 /* If count == 0, then the owner has released all buffers and he
2550 is no longer owner of the queue. Otherwise we have a new owner. */
2552 vdev->queue->owner = p->count ? file->private_data : NULL;
2555 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
2557 int vb2_ioctl_create_bufs(struct file *file, void *priv,
2558 struct v4l2_create_buffers *p)
2560 struct video_device *vdev = video_devdata(file);
2561 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
2563 p->index = vdev->queue->num_buffers;
2564 /* If count == 0, then just check if memory and type are valid.
2565 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
2567 return res != -EBUSY ? res : 0;
2570 if (vb2_queue_is_busy(vdev, file))
2572 res = __create_bufs(vdev->queue, p);
2574 vdev->queue->owner = file->private_data;
2577 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
2579 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
2580 struct v4l2_buffer *p)
2582 struct video_device *vdev = video_devdata(file);
2584 if (vb2_queue_is_busy(vdev, file))
2586 return vb2_prepare_buf(vdev->queue, p);
2588 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
2590 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
2592 struct video_device *vdev = video_devdata(file);
2594 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
2595 return vb2_querybuf(vdev->queue, p);
2597 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
2599 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2601 struct video_device *vdev = video_devdata(file);
2603 if (vb2_queue_is_busy(vdev, file))
2605 return vb2_qbuf(vdev->queue, p);
2607 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
2609 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2611 struct video_device *vdev = video_devdata(file);
2613 if (vb2_queue_is_busy(vdev, file))
2615 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
2617 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
2619 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
2621 struct video_device *vdev = video_devdata(file);
2623 if (vb2_queue_is_busy(vdev, file))
2625 return vb2_streamon(vdev->queue, i);
2627 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
2629 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
2631 struct video_device *vdev = video_devdata(file);
2633 if (vb2_queue_is_busy(vdev, file))
2635 return vb2_streamoff(vdev->queue, i);
2637 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
2639 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
2641 struct video_device *vdev = video_devdata(file);
2643 if (vb2_queue_is_busy(vdev, file))
2645 return vb2_expbuf(vdev->queue, p);
2647 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
2649 /* v4l2_file_operations helpers */
2651 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
2653 struct video_device *vdev = video_devdata(file);
2654 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2657 if (lock && mutex_lock_interruptible(lock))
2658 return -ERESTARTSYS;
2659 err = vb2_mmap(vdev->queue, vma);
2664 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
2666 int _vb2_fop_release(struct file *file, struct mutex *lock)
2668 struct video_device *vdev = video_devdata(file);
2670 if (file->private_data == vdev->queue->owner) {
2673 vb2_queue_release(vdev->queue);
2674 vdev->queue->owner = NULL;
2678 return v4l2_fh_release(file);
2680 EXPORT_SYMBOL_GPL(_vb2_fop_release);
2682 int vb2_fop_release(struct file *file)
2684 struct video_device *vdev = video_devdata(file);
2685 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2687 return _vb2_fop_release(file, lock);
2689 EXPORT_SYMBOL_GPL(vb2_fop_release);
2691 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
2692 size_t count, loff_t *ppos)
2694 struct video_device *vdev = video_devdata(file);
2695 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2698 if (lock && mutex_lock_interruptible(lock))
2699 return -ERESTARTSYS;
2700 if (vb2_queue_is_busy(vdev, file))
2702 err = vb2_write(vdev->queue, buf, count, ppos,
2703 file->f_flags & O_NONBLOCK);
2704 if (vdev->queue->fileio)
2705 vdev->queue->owner = file->private_data;
2711 EXPORT_SYMBOL_GPL(vb2_fop_write);
2713 ssize_t vb2_fop_read(struct file *file, char __user *buf,
2714 size_t count, loff_t *ppos)
2716 struct video_device *vdev = video_devdata(file);
2717 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2720 if (lock && mutex_lock_interruptible(lock))
2721 return -ERESTARTSYS;
2722 if (vb2_queue_is_busy(vdev, file))
2724 err = vb2_read(vdev->queue, buf, count, ppos,
2725 file->f_flags & O_NONBLOCK);
2726 if (vdev->queue->fileio)
2727 vdev->queue->owner = file->private_data;
2733 EXPORT_SYMBOL_GPL(vb2_fop_read);
2735 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
2737 struct video_device *vdev = video_devdata(file);
2738 struct vb2_queue *q = vdev->queue;
2739 struct mutex *lock = q->lock ? q->lock : vdev->lock;
2740 unsigned long req_events = poll_requested_events(wait);
2743 bool must_lock = false;
2745 /* Try to be smart: only lock if polling might start fileio,
2746 otherwise locking will only introduce unwanted delays. */
2747 if (q->num_buffers == 0 && q->fileio == NULL) {
2748 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2749 (req_events & (POLLIN | POLLRDNORM)))
2751 else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2752 (req_events & (POLLOUT | POLLWRNORM)))
2756 /* If locking is needed, but this helper doesn't know how, then you
2757 shouldn't be using this helper but you should write your own. */
2758 WARN_ON(must_lock && !lock);
2760 if (must_lock && lock && mutex_lock_interruptible(lock))
2765 res = vb2_poll(vdev->queue, file, wait);
2767 /* If fileio was started, then we have a new queue owner. */
2768 if (must_lock && !fileio && q->fileio)
2769 q->owner = file->private_data;
2770 if (must_lock && lock)
2774 EXPORT_SYMBOL_GPL(vb2_fop_poll);
2777 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
2778 unsigned long len, unsigned long pgoff, unsigned long flags)
2780 struct video_device *vdev = video_devdata(file);
2781 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2784 if (lock && mutex_lock_interruptible(lock))
2785 return -ERESTARTSYS;
2786 ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
2791 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
2794 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
2796 void vb2_ops_wait_prepare(struct vb2_queue *vq)
2798 mutex_unlock(vq->lock);
2800 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
2802 void vb2_ops_wait_finish(struct vb2_queue *vq)
2804 mutex_lock(vq->lock);
2806 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
2808 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
2809 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2810 MODULE_LICENSE("GPL");