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_offsets() - setup unique offsets ("cookies") for every plane in
149 * every buffer on the queue
151 static void __setup_offsets(struct vb2_queue *q, unsigned int n)
153 unsigned int buffer, plane;
154 struct vb2_buffer *vb;
157 if (q->num_buffers) {
158 struct v4l2_plane *p;
159 vb = q->bufs[q->num_buffers - 1];
160 p = &vb->v4l2_planes[vb->num_planes - 1];
161 off = PAGE_ALIGN(p->m.mem_offset + p->length);
166 for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) {
167 vb = q->bufs[buffer];
171 for (plane = 0; plane < vb->num_planes; ++plane) {
172 vb->v4l2_planes[plane].length = q->plane_sizes[plane];
173 vb->v4l2_planes[plane].m.mem_offset = off;
175 dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n",
178 off += vb->v4l2_planes[plane].length;
179 off = PAGE_ALIGN(off);
185 * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type)
186 * video buffer memory for all buffers/planes on the queue and initializes the
189 * Returns the number of buffers successfully allocated.
191 static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory,
192 unsigned int num_buffers, unsigned int num_planes)
195 struct vb2_buffer *vb;
198 for (buffer = 0; buffer < num_buffers; ++buffer) {
199 /* Allocate videobuf buffer structures */
200 vb = kzalloc(q->buf_struct_size, GFP_KERNEL);
202 dprintk(1, "Memory alloc for buffer struct failed\n");
206 /* Length stores number of planes for multiplanar buffers */
207 if (V4L2_TYPE_IS_MULTIPLANAR(q->type))
208 vb->v4l2_buf.length = num_planes;
210 vb->state = VB2_BUF_STATE_DEQUEUED;
212 vb->num_planes = num_planes;
213 vb->v4l2_buf.index = q->num_buffers + buffer;
214 vb->v4l2_buf.type = q->type;
215 vb->v4l2_buf.memory = memory;
217 /* Allocate video buffer memory for the MMAP type */
218 if (memory == V4L2_MEMORY_MMAP) {
219 ret = __vb2_buf_mem_alloc(vb);
221 dprintk(1, "Failed allocating memory for "
222 "buffer %d\n", buffer);
227 * Call the driver-provided buffer initialization
228 * callback, if given. An error in initialization
229 * results in queue setup failure.
231 ret = call_qop(q, buf_init, vb);
233 dprintk(1, "Buffer %d %p initialization"
234 " failed\n", buffer, vb);
235 __vb2_buf_mem_free(vb);
241 q->bufs[q->num_buffers + buffer] = vb;
244 if (memory == V4L2_MEMORY_MMAP)
245 __setup_offsets(q, buffer);
247 dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
254 * __vb2_free_mem() - release all video buffer memory for a given queue
256 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
259 struct vb2_buffer *vb;
261 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
263 vb = q->bufs[buffer];
267 /* Free MMAP buffers or release USERPTR buffers */
268 if (q->memory == V4L2_MEMORY_MMAP)
269 __vb2_buf_mem_free(vb);
270 else if (q->memory == V4L2_MEMORY_DMABUF)
271 __vb2_buf_dmabuf_put(vb);
273 __vb2_buf_userptr_put(vb);
278 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
279 * related information, if no buffers are left return the queue to an
280 * uninitialized state. Might be called even if the queue has already been freed.
282 static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
286 /* Call driver-provided cleanup function for each buffer, if provided */
287 if (q->ops->buf_cleanup) {
288 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
290 if (NULL == q->bufs[buffer])
292 q->ops->buf_cleanup(q->bufs[buffer]);
296 /* Release video buffer memory */
297 __vb2_free_mem(q, buffers);
299 /* Free videobuf buffers */
300 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
302 kfree(q->bufs[buffer]);
303 q->bufs[buffer] = NULL;
306 q->num_buffers -= buffers;
309 INIT_LIST_HEAD(&q->queued_list);
313 * __verify_planes_array() - verify that the planes array passed in struct
314 * v4l2_buffer from userspace can be safely used
316 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
318 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
321 /* Is memory for copying plane information present? */
322 if (NULL == b->m.planes) {
323 dprintk(1, "Multi-planar buffer passed but "
324 "planes array not provided\n");
328 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
329 dprintk(1, "Incorrect planes array length, "
330 "expected %d, got %d\n", vb->num_planes, b->length);
338 * __verify_length() - Verify that the bytesused value for each plane fits in
339 * the plane length and that the data offset doesn't exceed the bytesused value.
341 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
346 if (!V4L2_TYPE_IS_OUTPUT(b->type))
349 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
350 for (plane = 0; plane < vb->num_planes; ++plane) {
351 length = (b->memory == V4L2_MEMORY_USERPTR)
352 ? b->m.planes[plane].length
353 : vb->v4l2_planes[plane].length;
355 if (b->m.planes[plane].bytesused > length)
358 if (b->m.planes[plane].data_offset > 0 &&
359 b->m.planes[plane].data_offset >=
360 b->m.planes[plane].bytesused)
364 length = (b->memory == V4L2_MEMORY_USERPTR)
365 ? b->length : vb->v4l2_planes[0].length;
367 if (b->bytesused > length)
375 * __buffer_in_use() - return true if the buffer is in use and
376 * the queue cannot be freed (by the means of REQBUFS(0)) call
378 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
381 for (plane = 0; plane < vb->num_planes; ++plane) {
382 void *mem_priv = vb->planes[plane].mem_priv;
384 * If num_users() has not been provided, call_memop
385 * will return 0, apparently nobody cares about this
386 * case anyway. If num_users() returns more than 1,
387 * we are not the only user of the plane's memory.
389 if (mem_priv && call_memop(q, num_users, mem_priv) > 1)
396 * __buffers_in_use() - return true if any buffers on the queue are in use and
397 * the queue cannot be freed (by the means of REQBUFS(0)) call
399 static bool __buffers_in_use(struct vb2_queue *q)
402 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
403 if (__buffer_in_use(q, q->bufs[buffer]))
410 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
411 * returned to userspace
413 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
415 struct vb2_queue *q = vb->vb2_queue;
417 /* Copy back data such as timestamp, flags, etc. */
418 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
419 b->reserved2 = vb->v4l2_buf.reserved2;
420 b->reserved = vb->v4l2_buf.reserved;
422 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
424 * Fill in plane-related data if userspace provided an array
425 * for it. The caller has already verified memory and size.
427 b->length = vb->num_planes;
428 memcpy(b->m.planes, vb->v4l2_planes,
429 b->length * sizeof(struct v4l2_plane));
432 * We use length and offset in v4l2_planes array even for
433 * single-planar buffers, but userspace does not.
435 b->length = vb->v4l2_planes[0].length;
436 b->bytesused = vb->v4l2_planes[0].bytesused;
437 if (q->memory == V4L2_MEMORY_MMAP)
438 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
439 else if (q->memory == V4L2_MEMORY_USERPTR)
440 b->m.userptr = vb->v4l2_planes[0].m.userptr;
441 else if (q->memory == V4L2_MEMORY_DMABUF)
442 b->m.fd = vb->v4l2_planes[0].m.fd;
446 * Clear any buffer state related flags.
448 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
449 b->flags |= q->timestamp_type;
452 case VB2_BUF_STATE_QUEUED:
453 case VB2_BUF_STATE_ACTIVE:
454 b->flags |= V4L2_BUF_FLAG_QUEUED;
456 case VB2_BUF_STATE_ERROR:
457 b->flags |= V4L2_BUF_FLAG_ERROR;
459 case VB2_BUF_STATE_DONE:
460 b->flags |= V4L2_BUF_FLAG_DONE;
462 case VB2_BUF_STATE_PREPARED:
463 b->flags |= V4L2_BUF_FLAG_PREPARED;
465 case VB2_BUF_STATE_DEQUEUED:
470 if (__buffer_in_use(q, vb))
471 b->flags |= V4L2_BUF_FLAG_MAPPED;
475 * vb2_querybuf() - query video buffer information
477 * @b: buffer struct passed from userspace to vidioc_querybuf handler
480 * Should be called from vidioc_querybuf ioctl handler in driver.
481 * This function will verify the passed v4l2_buffer structure and fill the
482 * relevant information for the userspace.
484 * The return values from this function are intended to be directly returned
485 * from vidioc_querybuf handler in driver.
487 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
489 struct vb2_buffer *vb;
492 if (b->type != q->type) {
493 dprintk(1, "querybuf: wrong buffer type\n");
497 if (b->index >= q->num_buffers) {
498 dprintk(1, "querybuf: buffer index out of range\n");
501 vb = q->bufs[b->index];
502 ret = __verify_planes_array(vb, b);
504 __fill_v4l2_buffer(vb, b);
507 EXPORT_SYMBOL(vb2_querybuf);
510 * __verify_userptr_ops() - verify that all memory operations required for
511 * USERPTR queue type have been provided
513 static int __verify_userptr_ops(struct vb2_queue *q)
515 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
516 !q->mem_ops->put_userptr)
523 * __verify_mmap_ops() - verify that all memory operations required for
524 * MMAP queue type have been provided
526 static int __verify_mmap_ops(struct vb2_queue *q)
528 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
529 !q->mem_ops->put || !q->mem_ops->mmap)
536 * __verify_dmabuf_ops() - verify that all memory operations required for
537 * DMABUF queue type have been provided
539 static int __verify_dmabuf_ops(struct vb2_queue *q)
541 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
542 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
543 !q->mem_ops->unmap_dmabuf)
550 * __verify_memory_type() - Check whether the memory type and buffer type
551 * passed to a buffer operation are compatible with the queue.
553 static int __verify_memory_type(struct vb2_queue *q,
554 enum v4l2_memory memory, enum v4l2_buf_type type)
556 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
557 memory != V4L2_MEMORY_DMABUF) {
558 dprintk(1, "reqbufs: unsupported memory type\n");
562 if (type != q->type) {
563 dprintk(1, "reqbufs: requested type is incorrect\n");
568 * Make sure all the required memory ops for given memory type
571 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
572 dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
576 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
577 dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
581 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
582 dprintk(1, "reqbufs: DMABUF for current setup unsupported\n");
587 * Place the busy tests at the end: -EBUSY can be ignored when
588 * create_bufs is called with count == 0, but count == 0 should still
589 * do the memory and type validation.
592 dprintk(1, "reqbufs: file io in progress\n");
599 * __reqbufs() - Initiate streaming
600 * @q: videobuf2 queue
601 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
603 * Should be called from vidioc_reqbufs ioctl handler of a driver.
605 * 1) verifies streaming parameters passed from the userspace,
606 * 2) sets up the queue,
607 * 3) negotiates number of buffers and planes per buffer with the driver
608 * to be used during streaming,
609 * 4) allocates internal buffer structures (struct vb2_buffer), according to
610 * the agreed parameters,
611 * 5) for MMAP memory type, allocates actual video memory, using the
612 * memory handling/allocation routines provided during queue initialization
614 * If req->count is 0, all the memory will be freed instead.
615 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
616 * and the queue is not busy, memory will be reallocated.
618 * The return values from this function are intended to be directly returned
619 * from vidioc_reqbufs handler in driver.
621 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
623 unsigned int num_buffers, allocated_buffers, num_planes = 0;
627 dprintk(1, "reqbufs: streaming active\n");
631 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
633 * We already have buffers allocated, so first check if they
634 * are not in use and can be freed.
636 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
637 dprintk(1, "reqbufs: memory in use, cannot free\n");
641 __vb2_queue_free(q, q->num_buffers);
644 * In case of REQBUFS(0) return immediately without calling
645 * driver's queue_setup() callback and allocating resources.
652 * Make sure the requested values and current defaults are sane.
654 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
655 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
656 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
657 q->memory = req->memory;
660 * Ask the driver how many buffers and planes per buffer it requires.
661 * Driver also sets the size and allocator context for each plane.
663 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
664 q->plane_sizes, q->alloc_ctx);
668 /* Finally, allocate buffers and video memory */
669 ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
671 dprintk(1, "Memory allocation failed\n");
675 allocated_buffers = ret;
678 * Check if driver can handle the allocated number of buffers.
680 if (allocated_buffers < num_buffers) {
681 num_buffers = allocated_buffers;
683 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
684 &num_planes, q->plane_sizes, q->alloc_ctx);
686 if (!ret && allocated_buffers < num_buffers)
690 * Either the driver has accepted a smaller number of buffers,
691 * or .queue_setup() returned an error
695 q->num_buffers = allocated_buffers;
698 __vb2_queue_free(q, allocated_buffers);
703 * Return the number of successfully allocated buffers
706 req->count = allocated_buffers;
712 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
714 * @q: videobuf2 queue
715 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
717 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
719 int ret = __verify_memory_type(q, req->memory, req->type);
721 return ret ? ret : __reqbufs(q, req);
723 EXPORT_SYMBOL_GPL(vb2_reqbufs);
726 * __create_bufs() - Allocate buffers and any required auxiliary structs
727 * @q: videobuf2 queue
728 * @create: creation parameters, passed from userspace to vidioc_create_bufs
731 * Should be called from vidioc_create_bufs ioctl handler of a driver.
733 * 1) verifies parameter sanity
734 * 2) calls the .queue_setup() queue operation
735 * 3) performs any necessary memory allocations
737 * The return values from this function are intended to be directly returned
738 * from vidioc_create_bufs handler in driver.
740 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
742 unsigned int num_planes = 0, num_buffers, allocated_buffers;
745 if (q->num_buffers == VIDEO_MAX_FRAME) {
746 dprintk(1, "%s(): maximum number of buffers already allocated\n",
751 if (!q->num_buffers) {
752 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
753 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
754 q->memory = create->memory;
757 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
760 * Ask the driver, whether the requested number of buffers, planes per
761 * buffer and their sizes are acceptable
763 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
764 &num_planes, q->plane_sizes, q->alloc_ctx);
768 /* Finally, allocate buffers and video memory */
769 ret = __vb2_queue_alloc(q, create->memory, num_buffers,
772 dprintk(1, "Memory allocation failed\n");
776 allocated_buffers = ret;
779 * Check if driver can handle the so far allocated number of buffers.
781 if (ret < num_buffers) {
785 * q->num_buffers contains the total number of buffers, that the
786 * queue driver has set up
788 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
789 &num_planes, q->plane_sizes, q->alloc_ctx);
791 if (!ret && allocated_buffers < num_buffers)
795 * Either the driver has accepted a smaller number of buffers,
796 * or .queue_setup() returned an error
800 q->num_buffers += allocated_buffers;
803 __vb2_queue_free(q, allocated_buffers);
808 * Return the number of successfully allocated buffers
811 create->count = allocated_buffers;
817 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
818 * memory and type values.
819 * @q: videobuf2 queue
820 * @create: creation parameters, passed from userspace to vidioc_create_bufs
823 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
825 int ret = __verify_memory_type(q, create->memory, create->format.type);
827 create->index = q->num_buffers;
828 if (create->count == 0)
829 return ret != -EBUSY ? ret : 0;
830 return ret ? ret : __create_bufs(q, create);
832 EXPORT_SYMBOL_GPL(vb2_create_bufs);
835 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
836 * @vb: vb2_buffer to which the plane in question belongs to
837 * @plane_no: plane number for which the address is to be returned
839 * This function returns a kernel virtual address of a given plane if
840 * such a mapping exist, NULL otherwise.
842 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
844 struct vb2_queue *q = vb->vb2_queue;
846 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
849 return call_memop(q, vaddr, vb->planes[plane_no].mem_priv);
852 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
855 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
856 * @vb: vb2_buffer to which the plane in question belongs to
857 * @plane_no: plane number for which the cookie is to be returned
859 * This function returns an allocator specific cookie for a given plane if
860 * available, NULL otherwise. The allocator should provide some simple static
861 * inline function, which would convert this cookie to the allocator specific
862 * type that can be used directly by the driver to access the buffer. This can
863 * be for example physical address, pointer to scatter list or IOMMU mapping.
865 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
867 struct vb2_queue *q = vb->vb2_queue;
869 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
872 return call_memop(q, cookie, vb->planes[plane_no].mem_priv);
874 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
877 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
878 * @vb: vb2_buffer returned from the driver
879 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
880 * or VB2_BUF_STATE_ERROR if the operation finished with an error
882 * This function should be called by the driver after a hardware operation on
883 * a buffer is finished and the buffer may be returned to userspace. The driver
884 * cannot use this buffer anymore until it is queued back to it by videobuf
885 * by the means of buf_queue callback. Only buffers previously queued to the
886 * driver by buf_queue can be passed to this function.
888 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
890 struct vb2_queue *q = vb->vb2_queue;
894 if (vb->state != VB2_BUF_STATE_ACTIVE)
897 if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
900 dprintk(4, "Done processing on buffer %d, state: %d\n",
901 vb->v4l2_buf.index, state);
904 for (plane = 0; plane < vb->num_planes; ++plane)
905 call_memop(q, finish, vb->planes[plane].mem_priv);
907 /* Add the buffer to the done buffers list */
908 spin_lock_irqsave(&q->done_lock, flags);
910 list_add_tail(&vb->done_entry, &q->done_list);
911 atomic_dec(&q->queued_count);
912 spin_unlock_irqrestore(&q->done_lock, flags);
914 /* Inform any processes that may be waiting for buffers */
915 wake_up(&q->done_wq);
917 EXPORT_SYMBOL_GPL(vb2_buffer_done);
920 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
921 * v4l2_buffer by the userspace. The caller has already verified that struct
922 * v4l2_buffer has a valid number of planes.
924 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
925 struct v4l2_plane *v4l2_planes)
929 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
930 /* Fill in driver-provided information for OUTPUT types */
931 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
933 * Will have to go up to b->length when API starts
934 * accepting variable number of planes.
936 for (plane = 0; plane < vb->num_planes; ++plane) {
937 v4l2_planes[plane].bytesused =
938 b->m.planes[plane].bytesused;
939 v4l2_planes[plane].data_offset =
940 b->m.planes[plane].data_offset;
944 if (b->memory == V4L2_MEMORY_USERPTR) {
945 for (plane = 0; plane < vb->num_planes; ++plane) {
946 v4l2_planes[plane].m.userptr =
947 b->m.planes[plane].m.userptr;
948 v4l2_planes[plane].length =
949 b->m.planes[plane].length;
952 if (b->memory == V4L2_MEMORY_DMABUF) {
953 for (plane = 0; plane < vb->num_planes; ++plane) {
954 v4l2_planes[plane].m.fd =
955 b->m.planes[plane].m.fd;
956 v4l2_planes[plane].length =
957 b->m.planes[plane].length;
958 v4l2_planes[plane].data_offset =
959 b->m.planes[plane].data_offset;
964 * Single-planar buffers do not use planes array,
965 * so fill in relevant v4l2_buffer struct fields instead.
966 * In videobuf we use our internal V4l2_planes struct for
967 * single-planar buffers as well, for simplicity.
969 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
970 v4l2_planes[0].bytesused = b->bytesused;
971 v4l2_planes[0].data_offset = 0;
974 if (b->memory == V4L2_MEMORY_USERPTR) {
975 v4l2_planes[0].m.userptr = b->m.userptr;
976 v4l2_planes[0].length = b->length;
979 if (b->memory == V4L2_MEMORY_DMABUF) {
980 v4l2_planes[0].m.fd = b->m.fd;
981 v4l2_planes[0].length = b->length;
982 v4l2_planes[0].data_offset = 0;
987 vb->v4l2_buf.field = b->field;
988 vb->v4l2_buf.timestamp = b->timestamp;
989 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
993 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
995 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
997 struct v4l2_plane planes[VIDEO_MAX_PLANES];
998 struct vb2_queue *q = vb->vb2_queue;
1002 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1004 /* Copy relevant information provided by the userspace */
1005 __fill_vb2_buffer(vb, b, planes);
1007 for (plane = 0; plane < vb->num_planes; ++plane) {
1008 /* Skip the plane if already verified */
1009 if (vb->v4l2_planes[plane].m.userptr &&
1010 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1011 && vb->v4l2_planes[plane].length == planes[plane].length)
1014 dprintk(3, "qbuf: userspace address for plane %d changed, "
1015 "reacquiring memory\n", plane);
1017 /* Check if the provided plane buffer is large enough */
1018 if (planes[plane].length < q->plane_sizes[plane]) {
1019 dprintk(1, "qbuf: provided buffer size %u is less than "
1020 "setup size %u for plane %d\n",
1021 planes[plane].length,
1022 q->plane_sizes[plane], plane);
1027 /* Release previously acquired memory if present */
1028 if (vb->planes[plane].mem_priv)
1029 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1031 vb->planes[plane].mem_priv = NULL;
1032 vb->v4l2_planes[plane].m.userptr = 0;
1033 vb->v4l2_planes[plane].length = 0;
1035 /* Acquire each plane's memory */
1036 mem_priv = call_memop(q, get_userptr, q->alloc_ctx[plane],
1037 planes[plane].m.userptr,
1038 planes[plane].length, write);
1039 if (IS_ERR_OR_NULL(mem_priv)) {
1040 dprintk(1, "qbuf: failed acquiring userspace "
1041 "memory for plane %d\n", plane);
1042 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1045 vb->planes[plane].mem_priv = mem_priv;
1049 * Call driver-specific initialization on the newly acquired buffer,
1052 ret = call_qop(q, buf_init, vb);
1054 dprintk(1, "qbuf: buffer initialization failed\n");
1059 * Now that everything is in order, copy relevant information
1060 * provided by userspace.
1062 for (plane = 0; plane < vb->num_planes; ++plane)
1063 vb->v4l2_planes[plane] = planes[plane];
1067 /* In case of errors, release planes that were already acquired */
1068 for (plane = 0; plane < vb->num_planes; ++plane) {
1069 if (vb->planes[plane].mem_priv)
1070 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1071 vb->planes[plane].mem_priv = NULL;
1072 vb->v4l2_planes[plane].m.userptr = 0;
1073 vb->v4l2_planes[plane].length = 0;
1080 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1082 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1084 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1089 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1091 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1093 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1094 struct vb2_queue *q = vb->vb2_queue;
1098 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1100 /* Verify and copy relevant information provided by the userspace */
1101 __fill_vb2_buffer(vb, b, planes);
1103 for (plane = 0; plane < vb->num_planes; ++plane) {
1104 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1106 if (IS_ERR_OR_NULL(dbuf)) {
1107 dprintk(1, "qbuf: invalid dmabuf fd for plane %d\n",
1113 /* use DMABUF size if length is not provided */
1114 if (planes[plane].length == 0)
1115 planes[plane].length = dbuf->size;
1117 if (planes[plane].length < planes[plane].data_offset +
1118 q->plane_sizes[plane]) {
1119 dprintk(1, "qbuf: invalid dmabuf length for plane %d\n",
1125 /* Skip the plane if already verified */
1126 if (dbuf == vb->planes[plane].dbuf &&
1127 vb->v4l2_planes[plane].length == planes[plane].length) {
1132 dprintk(1, "qbuf: buffer for plane %d changed\n", plane);
1134 /* Release previously acquired memory if present */
1135 __vb2_plane_dmabuf_put(q, &vb->planes[plane]);
1136 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1138 /* Acquire each plane's memory */
1139 mem_priv = call_memop(q, attach_dmabuf, q->alloc_ctx[plane],
1140 dbuf, planes[plane].length, write);
1141 if (IS_ERR(mem_priv)) {
1142 dprintk(1, "qbuf: failed to attach dmabuf\n");
1143 ret = PTR_ERR(mem_priv);
1148 vb->planes[plane].dbuf = dbuf;
1149 vb->planes[plane].mem_priv = mem_priv;
1152 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1153 * really we want to do this just before the DMA, not while queueing
1156 for (plane = 0; plane < vb->num_planes; ++plane) {
1157 ret = call_memop(q, map_dmabuf, vb->planes[plane].mem_priv);
1159 dprintk(1, "qbuf: failed to map dmabuf for plane %d\n",
1163 vb->planes[plane].dbuf_mapped = 1;
1167 * Call driver-specific initialization on the newly acquired buffer,
1170 ret = call_qop(q, buf_init, vb);
1172 dprintk(1, "qbuf: buffer initialization failed\n");
1177 * Now that everything is in order, copy relevant information
1178 * provided by userspace.
1180 for (plane = 0; plane < vb->num_planes; ++plane)
1181 vb->v4l2_planes[plane] = planes[plane];
1185 /* In case of errors, release planes that were already acquired */
1186 __vb2_buf_dmabuf_put(vb);
1192 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1194 static void __enqueue_in_driver(struct vb2_buffer *vb)
1196 struct vb2_queue *q = vb->vb2_queue;
1199 vb->state = VB2_BUF_STATE_ACTIVE;
1200 atomic_inc(&q->queued_count);
1203 for (plane = 0; plane < vb->num_planes; ++plane)
1204 call_memop(q, prepare, vb->planes[plane].mem_priv);
1206 q->ops->buf_queue(vb);
1209 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1211 struct vb2_queue *q = vb->vb2_queue;
1214 ret = __verify_length(vb, b);
1216 dprintk(1, "%s(): plane parameters verification failed: %d\n",
1221 switch (q->memory) {
1222 case V4L2_MEMORY_MMAP:
1223 ret = __qbuf_mmap(vb, b);
1225 case V4L2_MEMORY_USERPTR:
1226 ret = __qbuf_userptr(vb, b);
1228 case V4L2_MEMORY_DMABUF:
1229 ret = __qbuf_dmabuf(vb, b);
1232 WARN(1, "Invalid queue type\n");
1237 ret = call_qop(q, buf_prepare, vb);
1239 dprintk(1, "qbuf: buffer preparation failed: %d\n", ret);
1241 vb->state = VB2_BUF_STATE_PREPARED;
1246 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1248 int (*handler)(struct vb2_queue *,
1249 struct v4l2_buffer *,
1250 struct vb2_buffer *))
1252 struct rw_semaphore *mmap_sem = NULL;
1253 struct vb2_buffer *vb;
1257 * In case of user pointer buffers vb2 allocators need to get direct
1258 * access to userspace pages. This requires getting the mmap semaphore
1259 * for read access in the current process structure. The same semaphore
1260 * is taken before calling mmap operation, while both qbuf/prepare_buf
1261 * and mmap are called by the driver or v4l2 core with the driver's lock
1262 * held. To avoid an AB-BA deadlock (mmap_sem then driver's lock in mmap
1263 * and driver's lock then mmap_sem in qbuf/prepare_buf) the videobuf2
1264 * core releases the driver's lock, takes mmap_sem and then takes the
1265 * driver's lock again.
1267 * To avoid racing with other vb2 calls, which might be called after
1268 * releasing the driver's lock, this operation is performed at the
1269 * beginning of qbuf/prepare_buf processing. This way the queue status
1270 * is consistent after getting the driver's lock back.
1272 if (q->memory == V4L2_MEMORY_USERPTR) {
1273 mmap_sem = ¤t->mm->mmap_sem;
1274 call_qop(q, wait_prepare, q);
1275 down_read(mmap_sem);
1276 call_qop(q, wait_finish, q);
1280 dprintk(1, "%s(): file io in progress\n", opname);
1285 if (b->type != q->type) {
1286 dprintk(1, "%s(): invalid buffer type\n", opname);
1291 if (b->index >= q->num_buffers) {
1292 dprintk(1, "%s(): buffer index out of range\n", opname);
1297 vb = q->bufs[b->index];
1299 /* Should never happen */
1300 dprintk(1, "%s(): buffer is NULL\n", opname);
1305 if (b->memory != q->memory) {
1306 dprintk(1, "%s(): invalid memory type\n", opname);
1311 ret = __verify_planes_array(vb, b);
1315 ret = handler(q, b, vb);
1319 /* Fill buffer information for the userspace */
1320 __fill_v4l2_buffer(vb, b);
1322 dprintk(1, "%s() of buffer %d succeeded\n", opname, vb->v4l2_buf.index);
1329 static int __vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1330 struct vb2_buffer *vb)
1332 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1333 dprintk(1, "%s(): invalid buffer state %d\n", __func__,
1338 return __buf_prepare(vb, b);
1342 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1343 * @q: videobuf2 queue
1344 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1347 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1349 * 1) verifies the passed buffer,
1350 * 2) calls buf_prepare callback in the driver (if provided), in which
1351 * driver-specific buffer initialization can be performed,
1353 * The return values from this function are intended to be directly returned
1354 * from vidioc_prepare_buf handler in driver.
1356 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1358 return vb2_queue_or_prepare_buf(q, b, "prepare_buf", __vb2_prepare_buf);
1360 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1362 static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b,
1363 struct vb2_buffer *vb)
1367 switch (vb->state) {
1368 case VB2_BUF_STATE_DEQUEUED:
1369 ret = __buf_prepare(vb, b);
1372 case VB2_BUF_STATE_PREPARED:
1375 dprintk(1, "qbuf: buffer already in use\n");
1380 * Add to the queued buffers list, a buffer will stay on it until
1381 * dequeued in dqbuf.
1383 list_add_tail(&vb->queued_entry, &q->queued_list);
1384 vb->state = VB2_BUF_STATE_QUEUED;
1387 * If already streaming, give the buffer to driver for processing.
1388 * If not, the buffer will be given to driver on next streamon.
1391 __enqueue_in_driver(vb);
1397 * vb2_qbuf() - Queue a buffer from userspace
1398 * @q: videobuf2 queue
1399 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1402 * Should be called from vidioc_qbuf ioctl handler of a driver.
1404 * 1) verifies the passed buffer,
1405 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1406 * which driver-specific buffer initialization can be performed,
1407 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1408 * callback for processing.
1410 * The return values from this function are intended to be directly returned
1411 * from vidioc_qbuf handler in driver.
1413 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1415 return vb2_queue_or_prepare_buf(q, b, "qbuf", __vb2_qbuf);
1417 EXPORT_SYMBOL_GPL(vb2_qbuf);
1420 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1423 * Will sleep if required for nonblocking == false.
1425 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1428 * All operations on vb_done_list are performed under done_lock
1429 * spinlock protection. However, buffers may be removed from
1430 * it and returned to userspace only while holding both driver's
1431 * lock and the done_lock spinlock. Thus we can be sure that as
1432 * long as we hold the driver's lock, the list will remain not
1433 * empty if list_empty() check succeeds.
1439 if (!q->streaming) {
1440 dprintk(1, "Streaming off, will not wait for buffers\n");
1444 if (!list_empty(&q->done_list)) {
1446 * Found a buffer that we were waiting for.
1452 dprintk(1, "Nonblocking and no buffers to dequeue, "
1458 * We are streaming and blocking, wait for another buffer to
1459 * become ready or for streamoff. Driver's lock is released to
1460 * allow streamoff or qbuf to be called while waiting.
1462 call_qop(q, wait_prepare, q);
1465 * All locks have been released, it is safe to sleep now.
1467 dprintk(3, "Will sleep waiting for buffers\n");
1468 ret = wait_event_interruptible(q->done_wq,
1469 !list_empty(&q->done_list) || !q->streaming);
1472 * We need to reevaluate both conditions again after reacquiring
1473 * the locks or return an error if one occurred.
1475 call_qop(q, wait_finish, q);
1477 dprintk(1, "Sleep was interrupted\n");
1485 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1487 * Will sleep if required for nonblocking == false.
1489 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1490 struct v4l2_buffer *b, int nonblocking)
1492 unsigned long flags;
1496 * Wait for at least one buffer to become available on the done_list.
1498 ret = __vb2_wait_for_done_vb(q, nonblocking);
1503 * Driver's lock has been held since we last verified that done_list
1504 * is not empty, so no need for another list_empty(done_list) check.
1506 spin_lock_irqsave(&q->done_lock, flags);
1507 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1509 * Only remove the buffer from done_list if v4l2_buffer can handle all
1512 ret = __verify_planes_array(*vb, b);
1514 list_del(&(*vb)->done_entry);
1515 spin_unlock_irqrestore(&q->done_lock, flags);
1521 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1522 * @q: videobuf2 queue
1524 * This function will wait until all buffers that have been given to the driver
1525 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1526 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1527 * taken, for example from stop_streaming() callback.
1529 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1531 if (!q->streaming) {
1532 dprintk(1, "Streaming off, will not wait for buffers\n");
1536 wait_event(q->done_wq, !atomic_read(&q->queued_count));
1539 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1542 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1544 static void __vb2_dqbuf(struct vb2_buffer *vb)
1546 struct vb2_queue *q = vb->vb2_queue;
1549 /* nothing to do if the buffer is already dequeued */
1550 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1553 vb->state = VB2_BUF_STATE_DEQUEUED;
1555 /* unmap DMABUF buffer */
1556 if (q->memory == V4L2_MEMORY_DMABUF)
1557 for (i = 0; i < vb->num_planes; ++i) {
1558 if (!vb->planes[i].dbuf_mapped)
1560 call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv);
1561 vb->planes[i].dbuf_mapped = 0;
1566 * vb2_dqbuf() - Dequeue a buffer to the userspace
1567 * @q: videobuf2 queue
1568 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
1570 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1571 * buffers ready for dequeuing are present. Normally the driver
1572 * would be passing (file->f_flags & O_NONBLOCK) here
1574 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1576 * 1) verifies the passed buffer,
1577 * 2) calls buf_finish callback in the driver (if provided), in which
1578 * driver can perform any additional operations that may be required before
1579 * returning the buffer to userspace, such as cache sync,
1580 * 3) the buffer struct members are filled with relevant information for
1583 * The return values from this function are intended to be directly returned
1584 * from vidioc_dqbuf handler in driver.
1586 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
1588 struct vb2_buffer *vb = NULL;
1592 dprintk(1, "dqbuf: file io in progress\n");
1596 if (b->type != q->type) {
1597 dprintk(1, "dqbuf: invalid buffer type\n");
1600 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
1604 ret = call_qop(q, buf_finish, vb);
1606 dprintk(1, "dqbuf: buffer finish failed\n");
1610 switch (vb->state) {
1611 case VB2_BUF_STATE_DONE:
1612 dprintk(3, "dqbuf: Returning done buffer\n");
1614 case VB2_BUF_STATE_ERROR:
1615 dprintk(3, "dqbuf: Returning done buffer with errors\n");
1618 dprintk(1, "dqbuf: Invalid buffer state\n");
1622 /* Fill buffer information for the userspace */
1623 __fill_v4l2_buffer(vb, b);
1624 /* Remove from videobuf queue */
1625 list_del(&vb->queued_entry);
1626 /* go back to dequeued state */
1629 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1630 vb->v4l2_buf.index, vb->state);
1634 EXPORT_SYMBOL_GPL(vb2_dqbuf);
1637 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1639 * Removes all queued buffers from driver's queue and all buffers queued by
1640 * userspace from videobuf's queue. Returns to state after reqbufs.
1642 static void __vb2_queue_cancel(struct vb2_queue *q)
1647 * Tell driver to stop all transactions and release all queued
1651 call_qop(q, stop_streaming, q);
1655 * Remove all buffers from videobuf's list...
1657 INIT_LIST_HEAD(&q->queued_list);
1659 * ...and done list; userspace will not receive any buffers it
1660 * has not already dequeued before initiating cancel.
1662 INIT_LIST_HEAD(&q->done_list);
1663 atomic_set(&q->queued_count, 0);
1664 wake_up_all(&q->done_wq);
1667 * Reinitialize all buffers for next use.
1669 for (i = 0; i < q->num_buffers; ++i)
1670 __vb2_dqbuf(q->bufs[i]);
1674 * vb2_streamon - start streaming
1675 * @q: videobuf2 queue
1676 * @type: type argument passed from userspace to vidioc_streamon handler
1678 * Should be called from vidioc_streamon handler of a driver.
1680 * 1) verifies current state
1681 * 2) passes any previously queued buffers to the driver and starts streaming
1683 * The return values from this function are intended to be directly returned
1684 * from vidioc_streamon handler in the driver.
1686 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
1688 struct vb2_buffer *vb;
1692 dprintk(1, "streamon: file io in progress\n");
1696 if (type != q->type) {
1697 dprintk(1, "streamon: invalid stream type\n");
1702 dprintk(3, "streamon successful: already streaming\n");
1707 * If any buffers were queued before streamon,
1708 * we can now pass them to driver for processing.
1710 list_for_each_entry(vb, &q->queued_list, queued_entry)
1711 __enqueue_in_driver(vb);
1714 * Let driver notice that streaming state has been enabled.
1716 ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
1718 dprintk(1, "streamon: driver refused to start streaming\n");
1719 __vb2_queue_cancel(q);
1725 dprintk(3, "Streamon successful\n");
1728 EXPORT_SYMBOL_GPL(vb2_streamon);
1732 * vb2_streamoff - stop streaming
1733 * @q: videobuf2 queue
1734 * @type: type argument passed from userspace to vidioc_streamoff handler
1736 * Should be called from vidioc_streamoff handler of a driver.
1738 * 1) verifies current state,
1739 * 2) stop streaming and dequeues any queued buffers, including those previously
1740 * passed to the driver (after waiting for the driver to finish).
1742 * This call can be used for pausing playback.
1743 * The return values from this function are intended to be directly returned
1744 * from vidioc_streamoff handler in the driver
1746 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
1749 dprintk(1, "streamoff: file io in progress\n");
1753 if (type != q->type) {
1754 dprintk(1, "streamoff: invalid stream type\n");
1758 if (!q->streaming) {
1759 dprintk(3, "streamoff successful: not streaming\n");
1764 * Cancel will pause streaming and remove all buffers from the driver
1765 * and videobuf, effectively returning control over them to userspace.
1767 __vb2_queue_cancel(q);
1769 dprintk(3, "Streamoff successful\n");
1772 EXPORT_SYMBOL_GPL(vb2_streamoff);
1775 * __find_plane_by_offset() - find plane associated with the given offset off
1777 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1778 unsigned int *_buffer, unsigned int *_plane)
1780 struct vb2_buffer *vb;
1781 unsigned int buffer, plane;
1784 * Go over all buffers and their planes, comparing the given offset
1785 * with an offset assigned to each plane. If a match is found,
1786 * return its buffer and plane numbers.
1788 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1789 vb = q->bufs[buffer];
1791 for (plane = 0; plane < vb->num_planes; ++plane) {
1792 if (vb->v4l2_planes[plane].m.mem_offset == off) {
1804 * vb2_expbuf() - Export a buffer as a file descriptor
1805 * @q: videobuf2 queue
1806 * @eb: export buffer structure passed from userspace to vidioc_expbuf
1809 * The return values from this function are intended to be directly returned
1810 * from vidioc_expbuf handler in driver.
1812 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
1814 struct vb2_buffer *vb = NULL;
1815 struct vb2_plane *vb_plane;
1817 struct dma_buf *dbuf;
1819 if (q->memory != V4L2_MEMORY_MMAP) {
1820 dprintk(1, "Queue is not currently set up for mmap\n");
1824 if (!q->mem_ops->get_dmabuf) {
1825 dprintk(1, "Queue does not support DMA buffer exporting\n");
1829 if (eb->flags & ~(O_CLOEXEC | O_ACCMODE)) {
1830 dprintk(1, "Queue does support only O_CLOEXEC and access mode flags\n");
1834 if (eb->type != q->type) {
1835 dprintk(1, "qbuf: invalid buffer type\n");
1839 if (eb->index >= q->num_buffers) {
1840 dprintk(1, "buffer index out of range\n");
1844 vb = q->bufs[eb->index];
1846 if (eb->plane >= vb->num_planes) {
1847 dprintk(1, "buffer plane out of range\n");
1851 vb_plane = &vb->planes[eb->plane];
1853 dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv, eb->flags & O_ACCMODE);
1854 if (IS_ERR_OR_NULL(dbuf)) {
1855 dprintk(1, "Failed to export buffer %d, plane %d\n",
1856 eb->index, eb->plane);
1860 ret = dma_buf_fd(dbuf, eb->flags & ~O_ACCMODE);
1862 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1863 eb->index, eb->plane, ret);
1868 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1869 eb->index, eb->plane, ret);
1874 EXPORT_SYMBOL_GPL(vb2_expbuf);
1877 * vb2_mmap() - map video buffers into application address space
1878 * @q: videobuf2 queue
1879 * @vma: vma passed to the mmap file operation handler in the driver
1881 * Should be called from mmap file operation handler of a driver.
1882 * This function maps one plane of one of the available video buffers to
1883 * userspace. To map whole video memory allocated on reqbufs, this function
1884 * has to be called once per each plane per each buffer previously allocated.
1886 * When the userspace application calls mmap, it passes to it an offset returned
1887 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
1888 * a "cookie", which is then used to identify the plane to be mapped.
1889 * This function finds a plane with a matching offset and a mapping is performed
1890 * by the means of a provided memory operation.
1892 * The return values from this function are intended to be directly returned
1893 * from the mmap handler in driver.
1895 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1897 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1898 struct vb2_buffer *vb;
1899 unsigned int buffer, plane;
1901 unsigned long length;
1903 if (q->memory != V4L2_MEMORY_MMAP) {
1904 dprintk(1, "Queue is not currently set up for mmap\n");
1909 * Check memory area access mode.
1911 if (!(vma->vm_flags & VM_SHARED)) {
1912 dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
1915 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1916 if (!(vma->vm_flags & VM_WRITE)) {
1917 dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
1921 if (!(vma->vm_flags & VM_READ)) {
1922 dprintk(1, "Invalid vma flags, VM_READ needed\n");
1928 * Find the plane corresponding to the offset passed by userspace.
1930 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1934 vb = q->bufs[buffer];
1937 * MMAP requires page_aligned buffers.
1938 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1939 * so, we need to do the same here.
1941 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
1942 if (length < (vma->vm_end - vma->vm_start)) {
1944 "MMAP invalid, as it would overflow buffer length\n");
1948 ret = call_memop(q, mmap, vb->planes[plane].mem_priv, vma);
1952 dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
1955 EXPORT_SYMBOL_GPL(vb2_mmap);
1958 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1961 unsigned long pgoff,
1962 unsigned long flags)
1964 unsigned long off = pgoff << PAGE_SHIFT;
1965 struct vb2_buffer *vb;
1966 unsigned int buffer, plane;
1969 if (q->memory != V4L2_MEMORY_MMAP) {
1970 dprintk(1, "Queue is not currently set up for mmap\n");
1975 * Find the plane corresponding to the offset passed by userspace.
1977 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1981 vb = q->bufs[buffer];
1983 return (unsigned long)vb2_plane_vaddr(vb, plane);
1985 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
1988 static int __vb2_init_fileio(struct vb2_queue *q, int read);
1989 static int __vb2_cleanup_fileio(struct vb2_queue *q);
1992 * vb2_poll() - implements poll userspace operation
1993 * @q: videobuf2 queue
1994 * @file: file argument passed to the poll file operation handler
1995 * @wait: wait argument passed to the poll file operation handler
1997 * This function implements poll file operation handler for a driver.
1998 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
1999 * be informed that the file descriptor of a video device is available for
2001 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
2002 * will be reported as available for writing.
2004 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
2007 * The return values from this function are intended to be directly returned
2008 * from poll handler in driver.
2010 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2012 struct video_device *vfd = video_devdata(file);
2013 unsigned long req_events = poll_requested_events(wait);
2014 struct vb2_buffer *vb = NULL;
2015 unsigned int res = 0;
2016 unsigned long flags;
2018 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2019 struct v4l2_fh *fh = file->private_data;
2021 if (v4l2_event_pending(fh))
2023 else if (req_events & POLLPRI)
2024 poll_wait(file, &fh->wait, wait);
2027 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2029 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2033 * Start file I/O emulator only if streaming API has not been used yet.
2035 if (q->num_buffers == 0 && q->fileio == NULL) {
2036 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2037 (req_events & (POLLIN | POLLRDNORM))) {
2038 if (__vb2_init_fileio(q, 1))
2039 return res | POLLERR;
2041 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2042 (req_events & (POLLOUT | POLLWRNORM))) {
2043 if (__vb2_init_fileio(q, 0))
2044 return res | POLLERR;
2046 * Write to OUTPUT queue can be done immediately.
2048 return res | POLLOUT | POLLWRNORM;
2053 * There is nothing to wait for if no buffers have already been queued.
2055 if (list_empty(&q->queued_list))
2056 return res | POLLERR;
2058 if (list_empty(&q->done_list))
2059 poll_wait(file, &q->done_wq, wait);
2062 * Take first buffer available for dequeuing.
2064 spin_lock_irqsave(&q->done_lock, flags);
2065 if (!list_empty(&q->done_list))
2066 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2068 spin_unlock_irqrestore(&q->done_lock, flags);
2070 if (vb && (vb->state == VB2_BUF_STATE_DONE
2071 || vb->state == VB2_BUF_STATE_ERROR)) {
2072 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2073 res | POLLOUT | POLLWRNORM :
2074 res | POLLIN | POLLRDNORM;
2078 EXPORT_SYMBOL_GPL(vb2_poll);
2081 * vb2_queue_init() - initialize a videobuf2 queue
2082 * @q: videobuf2 queue; this structure should be allocated in driver
2084 * The vb2_queue structure should be allocated by the driver. The driver is
2085 * responsible of clearing it's content and setting initial values for some
2086 * required entries before calling this function.
2087 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2088 * to the struct vb2_queue description in include/media/videobuf2-core.h
2089 * for more information.
2091 int vb2_queue_init(struct vb2_queue *q)
2098 WARN_ON(!q->mem_ops) ||
2099 WARN_ON(!q->type) ||
2100 WARN_ON(!q->io_modes) ||
2101 WARN_ON(!q->ops->queue_setup) ||
2102 WARN_ON(!q->ops->buf_queue) ||
2103 WARN_ON(q->timestamp_type & ~V4L2_BUF_FLAG_TIMESTAMP_MASK))
2106 /* Warn that the driver should choose an appropriate timestamp type */
2107 WARN_ON(q->timestamp_type == V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2109 INIT_LIST_HEAD(&q->queued_list);
2110 INIT_LIST_HEAD(&q->done_list);
2111 spin_lock_init(&q->done_lock);
2112 init_waitqueue_head(&q->done_wq);
2114 if (q->buf_struct_size == 0)
2115 q->buf_struct_size = sizeof(struct vb2_buffer);
2119 EXPORT_SYMBOL_GPL(vb2_queue_init);
2122 * vb2_queue_release() - stop streaming, release the queue and free memory
2123 * @q: videobuf2 queue
2125 * This function stops streaming and performs necessary clean ups, including
2126 * freeing video buffer memory. The driver is responsible for freeing
2127 * the vb2_queue structure itself.
2129 void vb2_queue_release(struct vb2_queue *q)
2131 __vb2_cleanup_fileio(q);
2132 __vb2_queue_cancel(q);
2133 __vb2_queue_free(q, q->num_buffers);
2135 EXPORT_SYMBOL_GPL(vb2_queue_release);
2138 * struct vb2_fileio_buf - buffer context used by file io emulator
2140 * vb2 provides a compatibility layer and emulator of file io (read and
2141 * write) calls on top of streaming API. This structure is used for
2142 * tracking context related to the buffers.
2144 struct vb2_fileio_buf {
2148 unsigned int queued:1;
2152 * struct vb2_fileio_data - queue context used by file io emulator
2154 * vb2 provides a compatibility layer and emulator of file io (read and
2155 * write) calls on top of streaming API. For proper operation it required
2156 * this structure to save the driver state between each call of the read
2157 * or write function.
2159 struct vb2_fileio_data {
2160 struct v4l2_requestbuffers req;
2161 struct v4l2_buffer b;
2162 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2164 unsigned int q_count;
2165 unsigned int dq_count;
2170 * __vb2_init_fileio() - initialize file io emulator
2171 * @q: videobuf2 queue
2172 * @read: mode selector (1 means read, 0 means write)
2174 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2176 struct vb2_fileio_data *fileio;
2178 unsigned int count = 0;
2183 if ((read && !(q->io_modes & VB2_READ)) ||
2184 (!read && !(q->io_modes & VB2_WRITE)))
2188 * Check if device supports mapping buffers to kernel virtual space.
2190 if (!q->mem_ops->vaddr)
2194 * Check if streaming api has not been already activated.
2196 if (q->streaming || q->num_buffers > 0)
2200 * Start with count 1, driver can increase it in queue_setup()
2204 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2205 (read) ? "read" : "write", count, q->io_flags);
2207 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2211 fileio->flags = q->io_flags;
2214 * Request buffers and use MMAP type to force driver
2215 * to allocate buffers by itself.
2217 fileio->req.count = count;
2218 fileio->req.memory = V4L2_MEMORY_MMAP;
2219 fileio->req.type = q->type;
2220 ret = vb2_reqbufs(q, &fileio->req);
2225 * Check if plane_count is correct
2226 * (multiplane buffers are not supported).
2228 if (q->bufs[0]->num_planes != 1) {
2234 * Get kernel address of each buffer.
2236 for (i = 0; i < q->num_buffers; i++) {
2237 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2238 if (fileio->bufs[i].vaddr == NULL) {
2242 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2246 * Read mode requires pre queuing of all buffers.
2250 * Queue all buffers.
2252 for (i = 0; i < q->num_buffers; i++) {
2253 struct v4l2_buffer *b = &fileio->b;
2254 memset(b, 0, sizeof(*b));
2256 b->memory = q->memory;
2258 ret = vb2_qbuf(q, b);
2261 fileio->bufs[i].queued = 1;
2267 ret = vb2_streamon(q, q->type);
2277 fileio->req.count = 0;
2278 vb2_reqbufs(q, &fileio->req);
2286 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2287 * @q: videobuf2 queue
2289 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2291 struct vb2_fileio_data *fileio = q->fileio;
2295 * Hack fileio context to enable direct calls to vb2 ioctl
2300 vb2_streamoff(q, q->type);
2301 fileio->req.count = 0;
2302 vb2_reqbufs(q, &fileio->req);
2304 dprintk(3, "file io emulator closed\n");
2310 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2311 * @q: videobuf2 queue
2312 * @data: pointed to target userspace buffer
2313 * @count: number of bytes to read or write
2314 * @ppos: file handle position tracking pointer
2315 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2316 * @read: access mode selector (1 means read, 0 means write)
2318 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2319 loff_t *ppos, int nonblock, int read)
2321 struct vb2_fileio_data *fileio;
2322 struct vb2_fileio_buf *buf;
2325 dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
2326 read ? "read" : "write", (long)*ppos, count,
2327 nonblock ? "non" : "");
2333 * Initialize emulator on first call.
2336 ret = __vb2_init_fileio(q, read);
2337 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2344 * Hack fileio context to enable direct calls to vb2 ioctl interface.
2345 * The pointer will be restored before returning from this function.
2349 index = fileio->index;
2350 buf = &fileio->bufs[index];
2353 * Check if we need to dequeue the buffer.
2356 struct vb2_buffer *vb;
2359 * Call vb2_dqbuf to get buffer back.
2361 memset(&fileio->b, 0, sizeof(fileio->b));
2362 fileio->b.type = q->type;
2363 fileio->b.memory = q->memory;
2364 fileio->b.index = index;
2365 ret = vb2_dqbuf(q, &fileio->b, nonblock);
2366 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2369 fileio->dq_count += 1;
2372 * Get number of bytes filled by the driver
2374 vb = q->bufs[index];
2375 buf->size = vb2_get_plane_payload(vb, 0);
2380 * Limit count on last few bytes of the buffer.
2382 if (buf->pos + count > buf->size) {
2383 count = buf->size - buf->pos;
2384 dprintk(5, "reducing read count: %zd\n", count);
2388 * Transfer data to userspace.
2390 dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n",
2391 count, index, buf->pos);
2393 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2395 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2397 dprintk(3, "file io: error copying data\n");
2409 * Queue next buffer if required.
2411 if (buf->pos == buf->size ||
2412 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
2414 * Check if this is the last buffer to read.
2416 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
2417 fileio->dq_count == 1) {
2418 dprintk(3, "file io: read limit reached\n");
2420 * Restore fileio pointer and release the context.
2423 return __vb2_cleanup_fileio(q);
2427 * Call vb2_qbuf and give buffer to the driver.
2429 memset(&fileio->b, 0, sizeof(fileio->b));
2430 fileio->b.type = q->type;
2431 fileio->b.memory = q->memory;
2432 fileio->b.index = index;
2433 fileio->b.bytesused = buf->pos;
2434 ret = vb2_qbuf(q, &fileio->b);
2435 dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
2440 * Buffer has been queued, update the status
2444 buf->size = q->bufs[0]->v4l2_planes[0].length;
2445 fileio->q_count += 1;
2448 * Switch to the next buffer
2450 fileio->index = (index + 1) % q->num_buffers;
2453 * Start streaming if required.
2455 if (!read && !q->streaming) {
2456 ret = vb2_streamon(q, q->type);
2463 * Return proper number of bytes processed.
2469 * Restore the fileio context and block vb2 ioctl interface.
2475 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2476 loff_t *ppos, int nonblocking)
2478 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2480 EXPORT_SYMBOL_GPL(vb2_read);
2482 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2483 loff_t *ppos, int nonblocking)
2485 return __vb2_perform_fileio(q, (char __user *) data, count,
2486 ppos, nonblocking, 0);
2488 EXPORT_SYMBOL_GPL(vb2_write);
2492 * The following functions are not part of the vb2 core API, but are helper
2493 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
2494 * and struct vb2_ops.
2495 * They contain boilerplate code that most if not all drivers have to do
2496 * and so they simplify the driver code.
2499 /* The queue is busy if there is a owner and you are not that owner. */
2500 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
2502 return vdev->queue->owner && vdev->queue->owner != file->private_data;
2505 /* vb2 ioctl helpers */
2507 int vb2_ioctl_reqbufs(struct file *file, void *priv,
2508 struct v4l2_requestbuffers *p)
2510 struct video_device *vdev = video_devdata(file);
2511 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
2515 if (vb2_queue_is_busy(vdev, file))
2517 res = __reqbufs(vdev->queue, p);
2518 /* If count == 0, then the owner has released all buffers and he
2519 is no longer owner of the queue. Otherwise we have a new owner. */
2521 vdev->queue->owner = p->count ? file->private_data : NULL;
2524 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
2526 int vb2_ioctl_create_bufs(struct file *file, void *priv,
2527 struct v4l2_create_buffers *p)
2529 struct video_device *vdev = video_devdata(file);
2530 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
2532 p->index = vdev->queue->num_buffers;
2533 /* If count == 0, then just check if memory and type are valid.
2534 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
2536 return res != -EBUSY ? res : 0;
2539 if (vb2_queue_is_busy(vdev, file))
2541 res = __create_bufs(vdev->queue, p);
2543 vdev->queue->owner = file->private_data;
2546 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
2548 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
2549 struct v4l2_buffer *p)
2551 struct video_device *vdev = video_devdata(file);
2553 if (vb2_queue_is_busy(vdev, file))
2555 return vb2_prepare_buf(vdev->queue, p);
2557 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
2559 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
2561 struct video_device *vdev = video_devdata(file);
2563 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
2564 return vb2_querybuf(vdev->queue, p);
2566 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
2568 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2570 struct video_device *vdev = video_devdata(file);
2572 if (vb2_queue_is_busy(vdev, file))
2574 return vb2_qbuf(vdev->queue, p);
2576 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
2578 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2580 struct video_device *vdev = video_devdata(file);
2582 if (vb2_queue_is_busy(vdev, file))
2584 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
2586 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
2588 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
2590 struct video_device *vdev = video_devdata(file);
2592 if (vb2_queue_is_busy(vdev, file))
2594 return vb2_streamon(vdev->queue, i);
2596 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
2598 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
2600 struct video_device *vdev = video_devdata(file);
2602 if (vb2_queue_is_busy(vdev, file))
2604 return vb2_streamoff(vdev->queue, i);
2606 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
2608 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
2610 struct video_device *vdev = video_devdata(file);
2612 if (vb2_queue_is_busy(vdev, file))
2614 return vb2_expbuf(vdev->queue, p);
2616 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
2618 /* v4l2_file_operations helpers */
2620 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
2622 struct video_device *vdev = video_devdata(file);
2623 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2626 if (lock && mutex_lock_interruptible(lock))
2627 return -ERESTARTSYS;
2628 err = vb2_mmap(vdev->queue, vma);
2633 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
2635 int _vb2_fop_release(struct file *file, struct mutex *lock)
2637 struct video_device *vdev = video_devdata(file);
2639 if (file->private_data == vdev->queue->owner) {
2642 vb2_queue_release(vdev->queue);
2643 vdev->queue->owner = NULL;
2647 return v4l2_fh_release(file);
2649 EXPORT_SYMBOL_GPL(_vb2_fop_release);
2651 int vb2_fop_release(struct file *file)
2653 struct video_device *vdev = video_devdata(file);
2654 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2656 return _vb2_fop_release(file, lock);
2658 EXPORT_SYMBOL_GPL(vb2_fop_release);
2660 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
2661 size_t count, loff_t *ppos)
2663 struct video_device *vdev = video_devdata(file);
2664 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2667 if (lock && mutex_lock_interruptible(lock))
2668 return -ERESTARTSYS;
2669 if (vb2_queue_is_busy(vdev, file))
2671 err = vb2_write(vdev->queue, buf, count, ppos,
2672 file->f_flags & O_NONBLOCK);
2673 if (vdev->queue->fileio)
2674 vdev->queue->owner = file->private_data;
2680 EXPORT_SYMBOL_GPL(vb2_fop_write);
2682 ssize_t vb2_fop_read(struct file *file, char __user *buf,
2683 size_t count, loff_t *ppos)
2685 struct video_device *vdev = video_devdata(file);
2686 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2689 if (lock && mutex_lock_interruptible(lock))
2690 return -ERESTARTSYS;
2691 if (vb2_queue_is_busy(vdev, file))
2693 err = vb2_read(vdev->queue, buf, count, ppos,
2694 file->f_flags & O_NONBLOCK);
2695 if (vdev->queue->fileio)
2696 vdev->queue->owner = file->private_data;
2702 EXPORT_SYMBOL_GPL(vb2_fop_read);
2704 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
2706 struct video_device *vdev = video_devdata(file);
2707 struct vb2_queue *q = vdev->queue;
2708 struct mutex *lock = q->lock ? q->lock : vdev->lock;
2709 unsigned long req_events = poll_requested_events(wait);
2712 bool must_lock = false;
2714 /* Try to be smart: only lock if polling might start fileio,
2715 otherwise locking will only introduce unwanted delays. */
2716 if (q->num_buffers == 0 && q->fileio == NULL) {
2717 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2718 (req_events & (POLLIN | POLLRDNORM)))
2720 else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2721 (req_events & (POLLOUT | POLLWRNORM)))
2725 /* If locking is needed, but this helper doesn't know how, then you
2726 shouldn't be using this helper but you should write your own. */
2727 WARN_ON(must_lock && !lock);
2729 if (must_lock && lock && mutex_lock_interruptible(lock))
2734 res = vb2_poll(vdev->queue, file, wait);
2736 /* If fileio was started, then we have a new queue owner. */
2737 if (must_lock && !fileio && q->fileio)
2738 q->owner = file->private_data;
2739 if (must_lock && lock)
2743 EXPORT_SYMBOL_GPL(vb2_fop_poll);
2746 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
2747 unsigned long len, unsigned long pgoff, unsigned long flags)
2749 struct video_device *vdev = video_devdata(file);
2750 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2753 if (lock && mutex_lock_interruptible(lock))
2754 return -ERESTARTSYS;
2755 ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
2760 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
2763 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
2765 void vb2_ops_wait_prepare(struct vb2_queue *vq)
2767 mutex_unlock(vq->lock);
2769 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
2771 void vb2_ops_wait_finish(struct vb2_queue *vq)
2773 mutex_lock(vq->lock);
2775 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
2777 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
2778 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2779 MODULE_LICENSE("GPL");