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 __setup_offsets(q, buffer);
246 dprintk(1, "Allocated %d buffers, %d plane(s) each\n",
253 * __vb2_free_mem() - release all video buffer memory for a given queue
255 static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers)
258 struct vb2_buffer *vb;
260 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
262 vb = q->bufs[buffer];
266 /* Free MMAP buffers or release USERPTR buffers */
267 if (q->memory == V4L2_MEMORY_MMAP)
268 __vb2_buf_mem_free(vb);
269 else if (q->memory == V4L2_MEMORY_DMABUF)
270 __vb2_buf_dmabuf_put(vb);
272 __vb2_buf_userptr_put(vb);
277 * __vb2_queue_free() - free buffers at the end of the queue - video memory and
278 * related information, if no buffers are left return the queue to an
279 * uninitialized state. Might be called even if the queue has already been freed.
281 static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers)
285 /* Call driver-provided cleanup function for each buffer, if provided */
286 if (q->ops->buf_cleanup) {
287 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
289 if (NULL == q->bufs[buffer])
291 q->ops->buf_cleanup(q->bufs[buffer]);
295 /* Release video buffer memory */
296 __vb2_free_mem(q, buffers);
298 /* Free videobuf buffers */
299 for (buffer = q->num_buffers - buffers; buffer < q->num_buffers;
301 kfree(q->bufs[buffer]);
302 q->bufs[buffer] = NULL;
305 q->num_buffers -= buffers;
308 INIT_LIST_HEAD(&q->queued_list);
312 * __verify_planes_array() - verify that the planes array passed in struct
313 * v4l2_buffer from userspace can be safely used
315 static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b)
317 if (!V4L2_TYPE_IS_MULTIPLANAR(b->type))
320 /* Is memory for copying plane information present? */
321 if (NULL == b->m.planes) {
322 dprintk(1, "Multi-planar buffer passed but "
323 "planes array not provided\n");
327 if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) {
328 dprintk(1, "Incorrect planes array length, "
329 "expected %d, got %d\n", vb->num_planes, b->length);
337 * __verify_length() - Verify that the bytesused value for each plane fits in
338 * the plane length and that the data offset doesn't exceed the bytesused value.
340 static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b)
345 if (!V4L2_TYPE_IS_OUTPUT(b->type))
348 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
349 for (plane = 0; plane < vb->num_planes; ++plane) {
350 length = (b->memory == V4L2_MEMORY_USERPTR)
351 ? b->m.planes[plane].length
352 : vb->v4l2_planes[plane].length;
354 if (b->m.planes[plane].bytesused > length)
356 if (b->m.planes[plane].data_offset >=
357 b->m.planes[plane].bytesused)
361 length = (b->memory == V4L2_MEMORY_USERPTR)
362 ? b->length : vb->v4l2_planes[0].length;
364 if (b->bytesused > length)
372 * __buffer_in_use() - return true if the buffer is in use and
373 * the queue cannot be freed (by the means of REQBUFS(0)) call
375 static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb)
378 for (plane = 0; plane < vb->num_planes; ++plane) {
379 void *mem_priv = vb->planes[plane].mem_priv;
381 * If num_users() has not been provided, call_memop
382 * will return 0, apparently nobody cares about this
383 * case anyway. If num_users() returns more than 1,
384 * we are not the only user of the plane's memory.
386 if (mem_priv && call_memop(q, num_users, mem_priv) > 1)
393 * __buffers_in_use() - return true if any buffers on the queue are in use and
394 * the queue cannot be freed (by the means of REQBUFS(0)) call
396 static bool __buffers_in_use(struct vb2_queue *q)
399 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
400 if (__buffer_in_use(q, q->bufs[buffer]))
407 * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be
408 * returned to userspace
410 static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
412 struct vb2_queue *q = vb->vb2_queue;
414 /* Copy back data such as timestamp, flags, etc. */
415 memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m));
416 b->reserved2 = vb->v4l2_buf.reserved2;
417 b->reserved = vb->v4l2_buf.reserved;
419 if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) {
421 * Fill in plane-related data if userspace provided an array
422 * for it. The caller has already verified memory and size.
424 b->length = vb->num_planes;
425 memcpy(b->m.planes, vb->v4l2_planes,
426 b->length * sizeof(struct v4l2_plane));
429 * We use length and offset in v4l2_planes array even for
430 * single-planar buffers, but userspace does not.
432 b->length = vb->v4l2_planes[0].length;
433 b->bytesused = vb->v4l2_planes[0].bytesused;
434 if (q->memory == V4L2_MEMORY_MMAP)
435 b->m.offset = vb->v4l2_planes[0].m.mem_offset;
436 else if (q->memory == V4L2_MEMORY_USERPTR)
437 b->m.userptr = vb->v4l2_planes[0].m.userptr;
438 else if (q->memory == V4L2_MEMORY_DMABUF)
439 b->m.fd = vb->v4l2_planes[0].m.fd;
443 * Clear any buffer state related flags.
445 b->flags &= ~V4L2_BUFFER_MASK_FLAGS;
446 b->flags |= q->timestamp_type;
449 case VB2_BUF_STATE_QUEUED:
450 case VB2_BUF_STATE_ACTIVE:
451 b->flags |= V4L2_BUF_FLAG_QUEUED;
453 case VB2_BUF_STATE_ERROR:
454 b->flags |= V4L2_BUF_FLAG_ERROR;
456 case VB2_BUF_STATE_DONE:
457 b->flags |= V4L2_BUF_FLAG_DONE;
459 case VB2_BUF_STATE_PREPARED:
460 b->flags |= V4L2_BUF_FLAG_PREPARED;
462 case VB2_BUF_STATE_DEQUEUED:
467 if (__buffer_in_use(q, vb))
468 b->flags |= V4L2_BUF_FLAG_MAPPED;
472 * vb2_querybuf() - query video buffer information
474 * @b: buffer struct passed from userspace to vidioc_querybuf handler
477 * Should be called from vidioc_querybuf ioctl handler in driver.
478 * This function will verify the passed v4l2_buffer structure and fill the
479 * relevant information for the userspace.
481 * The return values from this function are intended to be directly returned
482 * from vidioc_querybuf handler in driver.
484 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b)
486 struct vb2_buffer *vb;
489 if (b->type != q->type) {
490 dprintk(1, "querybuf: wrong buffer type\n");
494 if (b->index >= q->num_buffers) {
495 dprintk(1, "querybuf: buffer index out of range\n");
498 vb = q->bufs[b->index];
499 ret = __verify_planes_array(vb, b);
501 __fill_v4l2_buffer(vb, b);
504 EXPORT_SYMBOL(vb2_querybuf);
507 * __verify_userptr_ops() - verify that all memory operations required for
508 * USERPTR queue type have been provided
510 static int __verify_userptr_ops(struct vb2_queue *q)
512 if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr ||
513 !q->mem_ops->put_userptr)
520 * __verify_mmap_ops() - verify that all memory operations required for
521 * MMAP queue type have been provided
523 static int __verify_mmap_ops(struct vb2_queue *q)
525 if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc ||
526 !q->mem_ops->put || !q->mem_ops->mmap)
533 * __verify_dmabuf_ops() - verify that all memory operations required for
534 * DMABUF queue type have been provided
536 static int __verify_dmabuf_ops(struct vb2_queue *q)
538 if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf ||
539 !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf ||
540 !q->mem_ops->unmap_dmabuf)
547 * __verify_memory_type() - Check whether the memory type and buffer type
548 * passed to a buffer operation are compatible with the queue.
550 static int __verify_memory_type(struct vb2_queue *q,
551 enum v4l2_memory memory, enum v4l2_buf_type type)
553 if (memory != V4L2_MEMORY_MMAP && memory != V4L2_MEMORY_USERPTR &&
554 memory != V4L2_MEMORY_DMABUF) {
555 dprintk(1, "reqbufs: unsupported memory type\n");
559 if (type != q->type) {
560 dprintk(1, "reqbufs: requested type is incorrect\n");
565 * Make sure all the required memory ops for given memory type
568 if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) {
569 dprintk(1, "reqbufs: MMAP for current setup unsupported\n");
573 if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) {
574 dprintk(1, "reqbufs: USERPTR for current setup unsupported\n");
578 if (memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) {
579 dprintk(1, "reqbufs: DMABUF for current setup unsupported\n");
584 * Place the busy tests at the end: -EBUSY can be ignored when
585 * create_bufs is called with count == 0, but count == 0 should still
586 * do the memory and type validation.
589 dprintk(1, "reqbufs: file io in progress\n");
596 * __reqbufs() - Initiate streaming
597 * @q: videobuf2 queue
598 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
600 * Should be called from vidioc_reqbufs ioctl handler of a driver.
602 * 1) verifies streaming parameters passed from the userspace,
603 * 2) sets up the queue,
604 * 3) negotiates number of buffers and planes per buffer with the driver
605 * to be used during streaming,
606 * 4) allocates internal buffer structures (struct vb2_buffer), according to
607 * the agreed parameters,
608 * 5) for MMAP memory type, allocates actual video memory, using the
609 * memory handling/allocation routines provided during queue initialization
611 * If req->count is 0, all the memory will be freed instead.
612 * If the queue has been allocated previously (by a previous vb2_reqbufs) call
613 * and the queue is not busy, memory will be reallocated.
615 * The return values from this function are intended to be directly returned
616 * from vidioc_reqbufs handler in driver.
618 static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
620 unsigned int num_buffers, allocated_buffers, num_planes = 0;
624 dprintk(1, "reqbufs: streaming active\n");
628 if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) {
630 * We already have buffers allocated, so first check if they
631 * are not in use and can be freed.
633 if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) {
634 dprintk(1, "reqbufs: memory in use, cannot free\n");
638 __vb2_queue_free(q, q->num_buffers);
641 * In case of REQBUFS(0) return immediately without calling
642 * driver's queue_setup() callback and allocating resources.
649 * Make sure the requested values and current defaults are sane.
651 num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME);
652 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
653 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
654 q->memory = req->memory;
657 * Ask the driver how many buffers and planes per buffer it requires.
658 * Driver also sets the size and allocator context for each plane.
660 ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes,
661 q->plane_sizes, q->alloc_ctx);
665 /* Finally, allocate buffers and video memory */
666 ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes);
668 dprintk(1, "Memory allocation failed\n");
672 allocated_buffers = ret;
675 * Check if driver can handle the allocated number of buffers.
677 if (allocated_buffers < num_buffers) {
678 num_buffers = allocated_buffers;
680 ret = call_qop(q, queue_setup, q, NULL, &num_buffers,
681 &num_planes, q->plane_sizes, q->alloc_ctx);
683 if (!ret && allocated_buffers < num_buffers)
687 * Either the driver has accepted a smaller number of buffers,
688 * or .queue_setup() returned an error
692 q->num_buffers = allocated_buffers;
695 __vb2_queue_free(q, allocated_buffers);
700 * Return the number of successfully allocated buffers
703 req->count = allocated_buffers;
709 * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and
711 * @q: videobuf2 queue
712 * @req: struct passed from userspace to vidioc_reqbufs handler in driver
714 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
716 int ret = __verify_memory_type(q, req->memory, req->type);
718 return ret ? ret : __reqbufs(q, req);
720 EXPORT_SYMBOL_GPL(vb2_reqbufs);
723 * __create_bufs() - Allocate buffers and any required auxiliary structs
724 * @q: videobuf2 queue
725 * @create: creation parameters, passed from userspace to vidioc_create_bufs
728 * Should be called from vidioc_create_bufs ioctl handler of a driver.
730 * 1) verifies parameter sanity
731 * 2) calls the .queue_setup() queue operation
732 * 3) performs any necessary memory allocations
734 * The return values from this function are intended to be directly returned
735 * from vidioc_create_bufs handler in driver.
737 static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
739 unsigned int num_planes = 0, num_buffers, allocated_buffers;
742 if (q->num_buffers == VIDEO_MAX_FRAME) {
743 dprintk(1, "%s(): maximum number of buffers already allocated\n",
748 if (!q->num_buffers) {
749 memset(q->plane_sizes, 0, sizeof(q->plane_sizes));
750 memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx));
751 q->memory = create->memory;
754 num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers);
757 * Ask the driver, whether the requested number of buffers, planes per
758 * buffer and their sizes are acceptable
760 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
761 &num_planes, q->plane_sizes, q->alloc_ctx);
765 /* Finally, allocate buffers and video memory */
766 ret = __vb2_queue_alloc(q, create->memory, num_buffers,
769 dprintk(1, "Memory allocation failed\n");
773 allocated_buffers = ret;
776 * Check if driver can handle the so far allocated number of buffers.
778 if (ret < num_buffers) {
782 * q->num_buffers contains the total number of buffers, that the
783 * queue driver has set up
785 ret = call_qop(q, queue_setup, q, &create->format, &num_buffers,
786 &num_planes, q->plane_sizes, q->alloc_ctx);
788 if (!ret && allocated_buffers < num_buffers)
792 * Either the driver has accepted a smaller number of buffers,
793 * or .queue_setup() returned an error
797 q->num_buffers += allocated_buffers;
800 __vb2_queue_free(q, allocated_buffers);
805 * Return the number of successfully allocated buffers
808 create->count = allocated_buffers;
814 * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the
815 * memory and type values.
816 * @q: videobuf2 queue
817 * @create: creation parameters, passed from userspace to vidioc_create_bufs
820 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
822 int ret = __verify_memory_type(q, create->memory, create->format.type);
824 create->index = q->num_buffers;
825 if (create->count == 0)
826 return ret != -EBUSY ? ret : 0;
827 return ret ? ret : __create_bufs(q, create);
829 EXPORT_SYMBOL_GPL(vb2_create_bufs);
832 * vb2_plane_vaddr() - Return a kernel virtual address of a given plane
833 * @vb: vb2_buffer to which the plane in question belongs to
834 * @plane_no: plane number for which the address is to be returned
836 * This function returns a kernel virtual address of a given plane if
837 * such a mapping exist, NULL otherwise.
839 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no)
841 struct vb2_queue *q = vb->vb2_queue;
843 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
846 return call_memop(q, vaddr, vb->planes[plane_no].mem_priv);
849 EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
852 * vb2_plane_cookie() - Return allocator specific cookie for the given plane
853 * @vb: vb2_buffer to which the plane in question belongs to
854 * @plane_no: plane number for which the cookie is to be returned
856 * This function returns an allocator specific cookie for a given plane if
857 * available, NULL otherwise. The allocator should provide some simple static
858 * inline function, which would convert this cookie to the allocator specific
859 * type that can be used directly by the driver to access the buffer. This can
860 * be for example physical address, pointer to scatter list or IOMMU mapping.
862 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no)
864 struct vb2_queue *q = vb->vb2_queue;
866 if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
869 return call_memop(q, cookie, vb->planes[plane_no].mem_priv);
871 EXPORT_SYMBOL_GPL(vb2_plane_cookie);
874 * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished
875 * @vb: vb2_buffer returned from the driver
876 * @state: either VB2_BUF_STATE_DONE if the operation finished successfully
877 * or VB2_BUF_STATE_ERROR if the operation finished with an error
879 * This function should be called by the driver after a hardware operation on
880 * a buffer is finished and the buffer may be returned to userspace. The driver
881 * cannot use this buffer anymore until it is queued back to it by videobuf
882 * by the means of buf_queue callback. Only buffers previously queued to the
883 * driver by buf_queue can be passed to this function.
885 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state)
887 struct vb2_queue *q = vb->vb2_queue;
891 if (vb->state != VB2_BUF_STATE_ACTIVE)
894 if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR)
897 dprintk(4, "Done processing on buffer %d, state: %d\n",
898 vb->v4l2_buf.index, state);
901 for (plane = 0; plane < vb->num_planes; ++plane)
902 call_memop(q, finish, vb->planes[plane].mem_priv);
904 /* Add the buffer to the done buffers list */
905 spin_lock_irqsave(&q->done_lock, flags);
907 list_add_tail(&vb->done_entry, &q->done_list);
908 atomic_dec(&q->queued_count);
909 spin_unlock_irqrestore(&q->done_lock, flags);
911 /* Inform any processes that may be waiting for buffers */
912 wake_up(&q->done_wq);
914 EXPORT_SYMBOL_GPL(vb2_buffer_done);
917 * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a
918 * v4l2_buffer by the userspace. The caller has already verified that struct
919 * v4l2_buffer has a valid number of planes.
921 static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b,
922 struct v4l2_plane *v4l2_planes)
926 if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
927 /* Fill in driver-provided information for OUTPUT types */
928 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
930 * Will have to go up to b->length when API starts
931 * accepting variable number of planes.
933 for (plane = 0; plane < vb->num_planes; ++plane) {
934 v4l2_planes[plane].bytesused =
935 b->m.planes[plane].bytesused;
936 v4l2_planes[plane].data_offset =
937 b->m.planes[plane].data_offset;
941 if (b->memory == V4L2_MEMORY_USERPTR) {
942 for (plane = 0; plane < vb->num_planes; ++plane) {
943 v4l2_planes[plane].m.userptr =
944 b->m.planes[plane].m.userptr;
945 v4l2_planes[plane].length =
946 b->m.planes[plane].length;
949 if (b->memory == V4L2_MEMORY_DMABUF) {
950 for (plane = 0; plane < vb->num_planes; ++plane) {
951 v4l2_planes[plane].m.fd =
952 b->m.planes[plane].m.fd;
953 v4l2_planes[plane].length =
954 b->m.planes[plane].length;
955 v4l2_planes[plane].data_offset =
956 b->m.planes[plane].data_offset;
961 * Single-planar buffers do not use planes array,
962 * so fill in relevant v4l2_buffer struct fields instead.
963 * In videobuf we use our internal V4l2_planes struct for
964 * single-planar buffers as well, for simplicity.
966 if (V4L2_TYPE_IS_OUTPUT(b->type)) {
967 v4l2_planes[0].bytesused = b->bytesused;
968 v4l2_planes[0].data_offset = 0;
971 if (b->memory == V4L2_MEMORY_USERPTR) {
972 v4l2_planes[0].m.userptr = b->m.userptr;
973 v4l2_planes[0].length = b->length;
976 if (b->memory == V4L2_MEMORY_DMABUF) {
977 v4l2_planes[0].m.fd = b->m.fd;
978 v4l2_planes[0].length = b->length;
979 v4l2_planes[0].data_offset = 0;
984 vb->v4l2_buf.field = b->field;
985 vb->v4l2_buf.timestamp = b->timestamp;
986 vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
990 * __qbuf_userptr() - handle qbuf of a USERPTR buffer
992 static int __qbuf_userptr(struct vb2_buffer *vb, const struct v4l2_buffer *b)
994 struct v4l2_plane planes[VIDEO_MAX_PLANES];
995 struct vb2_queue *q = vb->vb2_queue;
999 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1001 /* Copy relevant information provided by the userspace */
1002 __fill_vb2_buffer(vb, b, planes);
1004 for (plane = 0; plane < vb->num_planes; ++plane) {
1005 /* Skip the plane if already verified */
1006 if (vb->v4l2_planes[plane].m.userptr &&
1007 vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
1008 && vb->v4l2_planes[plane].length == planes[plane].length)
1011 dprintk(3, "qbuf: userspace address for plane %d changed, "
1012 "reacquiring memory\n", plane);
1014 /* Check if the provided plane buffer is large enough */
1015 if (planes[plane].length < q->plane_sizes[plane]) {
1020 /* Release previously acquired memory if present */
1021 if (vb->planes[plane].mem_priv)
1022 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1024 vb->planes[plane].mem_priv = NULL;
1025 vb->v4l2_planes[plane].m.userptr = 0;
1026 vb->v4l2_planes[plane].length = 0;
1028 /* Acquire each plane's memory */
1029 mem_priv = call_memop(q, get_userptr, q->alloc_ctx[plane],
1030 planes[plane].m.userptr,
1031 planes[plane].length, write);
1032 if (IS_ERR_OR_NULL(mem_priv)) {
1033 dprintk(1, "qbuf: failed acquiring userspace "
1034 "memory for plane %d\n", plane);
1035 ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
1038 vb->planes[plane].mem_priv = mem_priv;
1042 * Call driver-specific initialization on the newly acquired buffer,
1045 ret = call_qop(q, buf_init, vb);
1047 dprintk(1, "qbuf: buffer initialization failed\n");
1052 * Now that everything is in order, copy relevant information
1053 * provided by userspace.
1055 for (plane = 0; plane < vb->num_planes; ++plane)
1056 vb->v4l2_planes[plane] = planes[plane];
1060 /* In case of errors, release planes that were already acquired */
1061 for (plane = 0; plane < vb->num_planes; ++plane) {
1062 if (vb->planes[plane].mem_priv)
1063 call_memop(q, put_userptr, vb->planes[plane].mem_priv);
1064 vb->planes[plane].mem_priv = NULL;
1065 vb->v4l2_planes[plane].m.userptr = 0;
1066 vb->v4l2_planes[plane].length = 0;
1073 * __qbuf_mmap() - handle qbuf of an MMAP buffer
1075 static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1077 __fill_vb2_buffer(vb, b, vb->v4l2_planes);
1082 * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
1084 static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1086 struct v4l2_plane planes[VIDEO_MAX_PLANES];
1087 struct vb2_queue *q = vb->vb2_queue;
1091 int write = !V4L2_TYPE_IS_OUTPUT(q->type);
1093 /* Verify and copy relevant information provided by the userspace */
1094 __fill_vb2_buffer(vb, b, planes);
1096 for (plane = 0; plane < vb->num_planes; ++plane) {
1097 struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
1099 if (IS_ERR_OR_NULL(dbuf)) {
1100 dprintk(1, "qbuf: invalid dmabuf fd for plane %d\n",
1106 /* use DMABUF size if length is not provided */
1107 if (planes[plane].length == 0)
1108 planes[plane].length = dbuf->size;
1110 if (planes[plane].length < planes[plane].data_offset +
1111 q->plane_sizes[plane]) {
1116 /* Skip the plane if already verified */
1117 if (dbuf == vb->planes[plane].dbuf &&
1118 vb->v4l2_planes[plane].length == planes[plane].length) {
1123 dprintk(1, "qbuf: buffer for plane %d changed\n", plane);
1125 /* Release previously acquired memory if present */
1126 __vb2_plane_dmabuf_put(q, &vb->planes[plane]);
1127 memset(&vb->v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
1129 /* Acquire each plane's memory */
1130 mem_priv = call_memop(q, attach_dmabuf, q->alloc_ctx[plane],
1131 dbuf, planes[plane].length, write);
1132 if (IS_ERR(mem_priv)) {
1133 dprintk(1, "qbuf: failed to attach dmabuf\n");
1134 ret = PTR_ERR(mem_priv);
1139 vb->planes[plane].dbuf = dbuf;
1140 vb->planes[plane].mem_priv = mem_priv;
1143 /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
1144 * really we want to do this just before the DMA, not while queueing
1147 for (plane = 0; plane < vb->num_planes; ++plane) {
1148 ret = call_memop(q, map_dmabuf, vb->planes[plane].mem_priv);
1150 dprintk(1, "qbuf: failed to map dmabuf for plane %d\n",
1154 vb->planes[plane].dbuf_mapped = 1;
1158 * Call driver-specific initialization on the newly acquired buffer,
1161 ret = call_qop(q, buf_init, vb);
1163 dprintk(1, "qbuf: buffer initialization failed\n");
1168 * Now that everything is in order, copy relevant information
1169 * provided by userspace.
1171 for (plane = 0; plane < vb->num_planes; ++plane)
1172 vb->v4l2_planes[plane] = planes[plane];
1176 /* In case of errors, release planes that were already acquired */
1177 __vb2_buf_dmabuf_put(vb);
1183 * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing
1185 static void __enqueue_in_driver(struct vb2_buffer *vb)
1187 struct vb2_queue *q = vb->vb2_queue;
1190 vb->state = VB2_BUF_STATE_ACTIVE;
1191 atomic_inc(&q->queued_count);
1194 for (plane = 0; plane < vb->num_planes; ++plane)
1195 call_memop(q, prepare, vb->planes[plane].mem_priv);
1197 q->ops->buf_queue(vb);
1200 static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b)
1202 struct vb2_queue *q = vb->vb2_queue;
1205 ret = __verify_length(vb, b);
1209 switch (q->memory) {
1210 case V4L2_MEMORY_MMAP:
1211 ret = __qbuf_mmap(vb, b);
1213 case V4L2_MEMORY_USERPTR:
1214 ret = __qbuf_userptr(vb, b);
1216 case V4L2_MEMORY_DMABUF:
1217 ret = __qbuf_dmabuf(vb, b);
1220 WARN(1, "Invalid queue type\n");
1225 ret = call_qop(q, buf_prepare, vb);
1227 dprintk(1, "qbuf: buffer preparation failed: %d\n", ret);
1229 vb->state = VB2_BUF_STATE_PREPARED;
1234 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1236 int (*handler)(struct vb2_queue *,
1237 struct v4l2_buffer *,
1238 struct vb2_buffer *))
1240 struct rw_semaphore *mmap_sem = NULL;
1241 struct vb2_buffer *vb;
1245 * In case of user pointer buffers vb2 allocators need to get direct
1246 * access to userspace pages. This requires getting the mmap semaphore
1247 * for read access in the current process structure. The same semaphore
1248 * is taken before calling mmap operation, while both qbuf/prepare_buf
1249 * and mmap are called by the driver or v4l2 core with the driver's lock
1250 * held. To avoid an AB-BA deadlock (mmap_sem then driver's lock in mmap
1251 * and driver's lock then mmap_sem in qbuf/prepare_buf) the videobuf2
1252 * core releases the driver's lock, takes mmap_sem and then takes the
1253 * driver's lock again.
1255 * To avoid racing with other vb2 calls, which might be called after
1256 * releasing the driver's lock, this operation is performed at the
1257 * beginning of qbuf/prepare_buf processing. This way the queue status
1258 * is consistent after getting the driver's lock back.
1260 if (q->memory == V4L2_MEMORY_USERPTR) {
1261 mmap_sem = ¤t->mm->mmap_sem;
1262 call_qop(q, wait_prepare, q);
1263 down_read(mmap_sem);
1264 call_qop(q, wait_finish, q);
1268 dprintk(1, "%s(): file io in progress\n", opname);
1273 if (b->type != q->type) {
1274 dprintk(1, "%s(): invalid buffer type\n", opname);
1279 if (b->index >= q->num_buffers) {
1280 dprintk(1, "%s(): buffer index out of range\n", opname);
1285 vb = q->bufs[b->index];
1287 /* Should never happen */
1288 dprintk(1, "%s(): buffer is NULL\n", opname);
1293 if (b->memory != q->memory) {
1294 dprintk(1, "%s(): invalid memory type\n", opname);
1299 ret = __verify_planes_array(vb, b);
1303 ret = handler(q, b, vb);
1307 /* Fill buffer information for the userspace */
1308 __fill_v4l2_buffer(vb, b);
1310 dprintk(1, "%s() of buffer %d succeeded\n", opname, vb->v4l2_buf.index);
1317 static int __vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
1318 struct vb2_buffer *vb)
1320 if (vb->state != VB2_BUF_STATE_DEQUEUED) {
1321 dprintk(1, "%s(): invalid buffer state %d\n", __func__,
1326 return __buf_prepare(vb, b);
1330 * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel
1331 * @q: videobuf2 queue
1332 * @b: buffer structure passed from userspace to vidioc_prepare_buf
1335 * Should be called from vidioc_prepare_buf ioctl handler of a driver.
1337 * 1) verifies the passed buffer,
1338 * 2) calls buf_prepare callback in the driver (if provided), in which
1339 * driver-specific buffer initialization can be performed,
1341 * The return values from this function are intended to be directly returned
1342 * from vidioc_prepare_buf handler in driver.
1344 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b)
1346 return vb2_queue_or_prepare_buf(q, b, "prepare_buf", __vb2_prepare_buf);
1348 EXPORT_SYMBOL_GPL(vb2_prepare_buf);
1350 static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b,
1351 struct vb2_buffer *vb)
1355 switch (vb->state) {
1356 case VB2_BUF_STATE_DEQUEUED:
1357 ret = __buf_prepare(vb, b);
1360 case VB2_BUF_STATE_PREPARED:
1363 dprintk(1, "qbuf: buffer already in use\n");
1368 * Add to the queued buffers list, a buffer will stay on it until
1369 * dequeued in dqbuf.
1371 list_add_tail(&vb->queued_entry, &q->queued_list);
1372 vb->state = VB2_BUF_STATE_QUEUED;
1375 * If already streaming, give the buffer to driver for processing.
1376 * If not, the buffer will be given to driver on next streamon.
1379 __enqueue_in_driver(vb);
1385 * vb2_qbuf() - Queue a buffer from userspace
1386 * @q: videobuf2 queue
1387 * @b: buffer structure passed from userspace to vidioc_qbuf handler
1390 * Should be called from vidioc_qbuf ioctl handler of a driver.
1392 * 1) verifies the passed buffer,
1393 * 2) if necessary, calls buf_prepare callback in the driver (if provided), in
1394 * which driver-specific buffer initialization can be performed,
1395 * 3) if streaming is on, queues the buffer in driver by the means of buf_queue
1396 * callback for processing.
1398 * The return values from this function are intended to be directly returned
1399 * from vidioc_qbuf handler in driver.
1401 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
1403 return vb2_queue_or_prepare_buf(q, b, "qbuf", __vb2_qbuf);
1405 EXPORT_SYMBOL_GPL(vb2_qbuf);
1408 * __vb2_wait_for_done_vb() - wait for a buffer to become available
1411 * Will sleep if required for nonblocking == false.
1413 static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking)
1416 * All operations on vb_done_list are performed under done_lock
1417 * spinlock protection. However, buffers may be removed from
1418 * it and returned to userspace only while holding both driver's
1419 * lock and the done_lock spinlock. Thus we can be sure that as
1420 * long as we hold the driver's lock, the list will remain not
1421 * empty if list_empty() check succeeds.
1427 if (!q->streaming) {
1428 dprintk(1, "Streaming off, will not wait for buffers\n");
1432 if (!list_empty(&q->done_list)) {
1434 * Found a buffer that we were waiting for.
1440 dprintk(1, "Nonblocking and no buffers to dequeue, "
1446 * We are streaming and blocking, wait for another buffer to
1447 * become ready or for streamoff. Driver's lock is released to
1448 * allow streamoff or qbuf to be called while waiting.
1450 call_qop(q, wait_prepare, q);
1453 * All locks have been released, it is safe to sleep now.
1455 dprintk(3, "Will sleep waiting for buffers\n");
1456 ret = wait_event_interruptible(q->done_wq,
1457 !list_empty(&q->done_list) || !q->streaming);
1460 * We need to reevaluate both conditions again after reacquiring
1461 * the locks or return an error if one occurred.
1463 call_qop(q, wait_finish, q);
1465 dprintk(1, "Sleep was interrupted\n");
1473 * __vb2_get_done_vb() - get a buffer ready for dequeuing
1475 * Will sleep if required for nonblocking == false.
1477 static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb,
1478 struct v4l2_buffer *b, int nonblocking)
1480 unsigned long flags;
1484 * Wait for at least one buffer to become available on the done_list.
1486 ret = __vb2_wait_for_done_vb(q, nonblocking);
1491 * Driver's lock has been held since we last verified that done_list
1492 * is not empty, so no need for another list_empty(done_list) check.
1494 spin_lock_irqsave(&q->done_lock, flags);
1495 *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry);
1497 * Only remove the buffer from done_list if v4l2_buffer can handle all
1500 ret = __verify_planes_array(*vb, b);
1502 list_del(&(*vb)->done_entry);
1503 spin_unlock_irqrestore(&q->done_lock, flags);
1509 * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2
1510 * @q: videobuf2 queue
1512 * This function will wait until all buffers that have been given to the driver
1513 * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call
1514 * wait_prepare, wait_finish pair. It is intended to be called with all locks
1515 * taken, for example from stop_streaming() callback.
1517 int vb2_wait_for_all_buffers(struct vb2_queue *q)
1519 if (!q->streaming) {
1520 dprintk(1, "Streaming off, will not wait for buffers\n");
1524 wait_event(q->done_wq, !atomic_read(&q->queued_count));
1527 EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);
1530 * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state
1532 static void __vb2_dqbuf(struct vb2_buffer *vb)
1534 struct vb2_queue *q = vb->vb2_queue;
1537 /* nothing to do if the buffer is already dequeued */
1538 if (vb->state == VB2_BUF_STATE_DEQUEUED)
1541 vb->state = VB2_BUF_STATE_DEQUEUED;
1543 /* unmap DMABUF buffer */
1544 if (q->memory == V4L2_MEMORY_DMABUF)
1545 for (i = 0; i < vb->num_planes; ++i) {
1546 if (!vb->planes[i].dbuf_mapped)
1548 call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv);
1549 vb->planes[i].dbuf_mapped = 0;
1554 * vb2_dqbuf() - Dequeue a buffer to the userspace
1555 * @q: videobuf2 queue
1556 * @b: buffer structure passed from userspace to vidioc_dqbuf handler
1558 * @nonblocking: if true, this call will not sleep waiting for a buffer if no
1559 * buffers ready for dequeuing are present. Normally the driver
1560 * would be passing (file->f_flags & O_NONBLOCK) here
1562 * Should be called from vidioc_dqbuf ioctl handler of a driver.
1564 * 1) verifies the passed buffer,
1565 * 2) calls buf_finish callback in the driver (if provided), in which
1566 * driver can perform any additional operations that may be required before
1567 * returning the buffer to userspace, such as cache sync,
1568 * 3) the buffer struct members are filled with relevant information for
1571 * The return values from this function are intended to be directly returned
1572 * from vidioc_dqbuf handler in driver.
1574 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking)
1576 struct vb2_buffer *vb = NULL;
1580 dprintk(1, "dqbuf: file io in progress\n");
1584 if (b->type != q->type) {
1585 dprintk(1, "dqbuf: invalid buffer type\n");
1588 ret = __vb2_get_done_vb(q, &vb, b, nonblocking);
1592 ret = call_qop(q, buf_finish, vb);
1594 dprintk(1, "dqbuf: buffer finish failed\n");
1598 switch (vb->state) {
1599 case VB2_BUF_STATE_DONE:
1600 dprintk(3, "dqbuf: Returning done buffer\n");
1602 case VB2_BUF_STATE_ERROR:
1603 dprintk(3, "dqbuf: Returning done buffer with errors\n");
1606 dprintk(1, "dqbuf: Invalid buffer state\n");
1610 /* Fill buffer information for the userspace */
1611 __fill_v4l2_buffer(vb, b);
1612 /* Remove from videobuf queue */
1613 list_del(&vb->queued_entry);
1614 /* go back to dequeued state */
1617 dprintk(1, "dqbuf of buffer %d, with state %d\n",
1618 vb->v4l2_buf.index, vb->state);
1622 EXPORT_SYMBOL_GPL(vb2_dqbuf);
1625 * __vb2_queue_cancel() - cancel and stop (pause) streaming
1627 * Removes all queued buffers from driver's queue and all buffers queued by
1628 * userspace from videobuf's queue. Returns to state after reqbufs.
1630 static void __vb2_queue_cancel(struct vb2_queue *q)
1635 * Tell driver to stop all transactions and release all queued
1639 call_qop(q, stop_streaming, q);
1643 * Remove all buffers from videobuf's list...
1645 INIT_LIST_HEAD(&q->queued_list);
1647 * ...and done list; userspace will not receive any buffers it
1648 * has not already dequeued before initiating cancel.
1650 INIT_LIST_HEAD(&q->done_list);
1651 atomic_set(&q->queued_count, 0);
1652 wake_up_all(&q->done_wq);
1655 * Reinitialize all buffers for next use.
1657 for (i = 0; i < q->num_buffers; ++i)
1658 __vb2_dqbuf(q->bufs[i]);
1662 * vb2_streamon - start streaming
1663 * @q: videobuf2 queue
1664 * @type: type argument passed from userspace to vidioc_streamon handler
1666 * Should be called from vidioc_streamon handler of a driver.
1668 * 1) verifies current state
1669 * 2) passes any previously queued buffers to the driver and starts streaming
1671 * The return values from this function are intended to be directly returned
1672 * from vidioc_streamon handler in the driver.
1674 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type)
1676 struct vb2_buffer *vb;
1680 dprintk(1, "streamon: file io in progress\n");
1684 if (type != q->type) {
1685 dprintk(1, "streamon: invalid stream type\n");
1690 dprintk(1, "streamon: already streaming\n");
1695 * If any buffers were queued before streamon,
1696 * we can now pass them to driver for processing.
1698 list_for_each_entry(vb, &q->queued_list, queued_entry)
1699 __enqueue_in_driver(vb);
1702 * Let driver notice that streaming state has been enabled.
1704 ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count));
1706 dprintk(1, "streamon: driver refused to start streaming\n");
1707 __vb2_queue_cancel(q);
1713 dprintk(3, "Streamon successful\n");
1716 EXPORT_SYMBOL_GPL(vb2_streamon);
1720 * vb2_streamoff - stop streaming
1721 * @q: videobuf2 queue
1722 * @type: type argument passed from userspace to vidioc_streamoff handler
1724 * Should be called from vidioc_streamoff handler of a driver.
1726 * 1) verifies current state,
1727 * 2) stop streaming and dequeues any queued buffers, including those previously
1728 * passed to the driver (after waiting for the driver to finish).
1730 * This call can be used for pausing playback.
1731 * The return values from this function are intended to be directly returned
1732 * from vidioc_streamoff handler in the driver
1734 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type)
1737 dprintk(1, "streamoff: file io in progress\n");
1741 if (type != q->type) {
1742 dprintk(1, "streamoff: invalid stream type\n");
1746 if (!q->streaming) {
1747 dprintk(1, "streamoff: not streaming\n");
1752 * Cancel will pause streaming and remove all buffers from the driver
1753 * and videobuf, effectively returning control over them to userspace.
1755 __vb2_queue_cancel(q);
1757 dprintk(3, "Streamoff successful\n");
1760 EXPORT_SYMBOL_GPL(vb2_streamoff);
1763 * __find_plane_by_offset() - find plane associated with the given offset off
1765 static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off,
1766 unsigned int *_buffer, unsigned int *_plane)
1768 struct vb2_buffer *vb;
1769 unsigned int buffer, plane;
1772 * Go over all buffers and their planes, comparing the given offset
1773 * with an offset assigned to each plane. If a match is found,
1774 * return its buffer and plane numbers.
1776 for (buffer = 0; buffer < q->num_buffers; ++buffer) {
1777 vb = q->bufs[buffer];
1779 for (plane = 0; plane < vb->num_planes; ++plane) {
1780 if (vb->v4l2_planes[plane].m.mem_offset == off) {
1792 * vb2_expbuf() - Export a buffer as a file descriptor
1793 * @q: videobuf2 queue
1794 * @eb: export buffer structure passed from userspace to vidioc_expbuf
1797 * The return values from this function are intended to be directly returned
1798 * from vidioc_expbuf handler in driver.
1800 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb)
1802 struct vb2_buffer *vb = NULL;
1803 struct vb2_plane *vb_plane;
1805 struct dma_buf *dbuf;
1807 if (q->memory != V4L2_MEMORY_MMAP) {
1808 dprintk(1, "Queue is not currently set up for mmap\n");
1812 if (!q->mem_ops->get_dmabuf) {
1813 dprintk(1, "Queue does not support DMA buffer exporting\n");
1817 if (eb->flags & ~O_CLOEXEC) {
1818 dprintk(1, "Queue does support only O_CLOEXEC flag\n");
1822 if (eb->type != q->type) {
1823 dprintk(1, "qbuf: invalid buffer type\n");
1827 if (eb->index >= q->num_buffers) {
1828 dprintk(1, "buffer index out of range\n");
1832 vb = q->bufs[eb->index];
1834 if (eb->plane >= vb->num_planes) {
1835 dprintk(1, "buffer plane out of range\n");
1839 vb_plane = &vb->planes[eb->plane];
1841 dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv);
1842 if (IS_ERR_OR_NULL(dbuf)) {
1843 dprintk(1, "Failed to export buffer %d, plane %d\n",
1844 eb->index, eb->plane);
1848 ret = dma_buf_fd(dbuf, eb->flags);
1850 dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
1851 eb->index, eb->plane, ret);
1856 dprintk(3, "buffer %d, plane %d exported as %d descriptor\n",
1857 eb->index, eb->plane, ret);
1862 EXPORT_SYMBOL_GPL(vb2_expbuf);
1865 * vb2_mmap() - map video buffers into application address space
1866 * @q: videobuf2 queue
1867 * @vma: vma passed to the mmap file operation handler in the driver
1869 * Should be called from mmap file operation handler of a driver.
1870 * This function maps one plane of one of the available video buffers to
1871 * userspace. To map whole video memory allocated on reqbufs, this function
1872 * has to be called once per each plane per each buffer previously allocated.
1874 * When the userspace application calls mmap, it passes to it an offset returned
1875 * to it earlier by the means of vidioc_querybuf handler. That offset acts as
1876 * a "cookie", which is then used to identify the plane to be mapped.
1877 * This function finds a plane with a matching offset and a mapping is performed
1878 * by the means of a provided memory operation.
1880 * The return values from this function are intended to be directly returned
1881 * from the mmap handler in driver.
1883 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
1885 unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
1886 struct vb2_buffer *vb;
1887 unsigned int buffer, plane;
1889 unsigned long length;
1891 if (q->memory != V4L2_MEMORY_MMAP) {
1892 dprintk(1, "Queue is not currently set up for mmap\n");
1897 * Check memory area access mode.
1899 if (!(vma->vm_flags & VM_SHARED)) {
1900 dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
1903 if (V4L2_TYPE_IS_OUTPUT(q->type)) {
1904 if (!(vma->vm_flags & VM_WRITE)) {
1905 dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
1909 if (!(vma->vm_flags & VM_READ)) {
1910 dprintk(1, "Invalid vma flags, VM_READ needed\n");
1916 * Find the plane corresponding to the offset passed by userspace.
1918 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1922 vb = q->bufs[buffer];
1925 * MMAP requires page_aligned buffers.
1926 * The buffer length was page_aligned at __vb2_buf_mem_alloc(),
1927 * so, we need to do the same here.
1929 length = PAGE_ALIGN(vb->v4l2_planes[plane].length);
1930 if (length < (vma->vm_end - vma->vm_start)) {
1932 "MMAP invalid, as it would overflow buffer length\n");
1936 ret = call_memop(q, mmap, vb->planes[plane].mem_priv, vma);
1940 dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane);
1943 EXPORT_SYMBOL_GPL(vb2_mmap);
1946 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
1949 unsigned long pgoff,
1950 unsigned long flags)
1952 unsigned long off = pgoff << PAGE_SHIFT;
1953 struct vb2_buffer *vb;
1954 unsigned int buffer, plane;
1957 if (q->memory != V4L2_MEMORY_MMAP) {
1958 dprintk(1, "Queue is not currently set up for mmap\n");
1963 * Find the plane corresponding to the offset passed by userspace.
1965 ret = __find_plane_by_offset(q, off, &buffer, &plane);
1969 vb = q->bufs[buffer];
1971 return (unsigned long)vb2_plane_vaddr(vb, plane);
1973 EXPORT_SYMBOL_GPL(vb2_get_unmapped_area);
1976 static int __vb2_init_fileio(struct vb2_queue *q, int read);
1977 static int __vb2_cleanup_fileio(struct vb2_queue *q);
1980 * vb2_poll() - implements poll userspace operation
1981 * @q: videobuf2 queue
1982 * @file: file argument passed to the poll file operation handler
1983 * @wait: wait argument passed to the poll file operation handler
1985 * This function implements poll file operation handler for a driver.
1986 * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
1987 * be informed that the file descriptor of a video device is available for
1989 * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
1990 * will be reported as available for writing.
1992 * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any
1995 * The return values from this function are intended to be directly returned
1996 * from poll handler in driver.
1998 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait)
2000 struct video_device *vfd = video_devdata(file);
2001 unsigned long req_events = poll_requested_events(wait);
2002 struct vb2_buffer *vb = NULL;
2003 unsigned int res = 0;
2004 unsigned long flags;
2006 if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
2007 struct v4l2_fh *fh = file->private_data;
2009 if (v4l2_event_pending(fh))
2011 else if (req_events & POLLPRI)
2012 poll_wait(file, &fh->wait, wait);
2015 if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM)))
2017 if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM)))
2021 * Start file I/O emulator only if streaming API has not been used yet.
2023 if (q->num_buffers == 0 && q->fileio == NULL) {
2024 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2025 (req_events & (POLLIN | POLLRDNORM))) {
2026 if (__vb2_init_fileio(q, 1))
2027 return res | POLLERR;
2029 if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2030 (req_events & (POLLOUT | POLLWRNORM))) {
2031 if (__vb2_init_fileio(q, 0))
2032 return res | POLLERR;
2034 * Write to OUTPUT queue can be done immediately.
2036 return res | POLLOUT | POLLWRNORM;
2041 * There is nothing to wait for if no buffers have already been queued.
2043 if (list_empty(&q->queued_list))
2044 return res | POLLERR;
2046 if (list_empty(&q->done_list))
2047 poll_wait(file, &q->done_wq, wait);
2050 * Take first buffer available for dequeuing.
2052 spin_lock_irqsave(&q->done_lock, flags);
2053 if (!list_empty(&q->done_list))
2054 vb = list_first_entry(&q->done_list, struct vb2_buffer,
2056 spin_unlock_irqrestore(&q->done_lock, flags);
2058 if (vb && (vb->state == VB2_BUF_STATE_DONE
2059 || vb->state == VB2_BUF_STATE_ERROR)) {
2060 return (V4L2_TYPE_IS_OUTPUT(q->type)) ?
2061 res | POLLOUT | POLLWRNORM :
2062 res | POLLIN | POLLRDNORM;
2066 EXPORT_SYMBOL_GPL(vb2_poll);
2069 * vb2_queue_init() - initialize a videobuf2 queue
2070 * @q: videobuf2 queue; this structure should be allocated in driver
2072 * The vb2_queue structure should be allocated by the driver. The driver is
2073 * responsible of clearing it's content and setting initial values for some
2074 * required entries before calling this function.
2075 * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer
2076 * to the struct vb2_queue description in include/media/videobuf2-core.h
2077 * for more information.
2079 int vb2_queue_init(struct vb2_queue *q)
2086 WARN_ON(!q->mem_ops) ||
2087 WARN_ON(!q->type) ||
2088 WARN_ON(!q->io_modes) ||
2089 WARN_ON(!q->ops->queue_setup) ||
2090 WARN_ON(!q->ops->buf_queue) ||
2091 WARN_ON(q->timestamp_type & ~V4L2_BUF_FLAG_TIMESTAMP_MASK))
2094 /* Warn that the driver should choose an appropriate timestamp type */
2095 WARN_ON(q->timestamp_type == V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN);
2097 INIT_LIST_HEAD(&q->queued_list);
2098 INIT_LIST_HEAD(&q->done_list);
2099 spin_lock_init(&q->done_lock);
2100 init_waitqueue_head(&q->done_wq);
2102 if (q->buf_struct_size == 0)
2103 q->buf_struct_size = sizeof(struct vb2_buffer);
2107 EXPORT_SYMBOL_GPL(vb2_queue_init);
2110 * vb2_queue_release() - stop streaming, release the queue and free memory
2111 * @q: videobuf2 queue
2113 * This function stops streaming and performs necessary clean ups, including
2114 * freeing video buffer memory. The driver is responsible for freeing
2115 * the vb2_queue structure itself.
2117 void vb2_queue_release(struct vb2_queue *q)
2119 __vb2_cleanup_fileio(q);
2120 __vb2_queue_cancel(q);
2121 __vb2_queue_free(q, q->num_buffers);
2123 EXPORT_SYMBOL_GPL(vb2_queue_release);
2126 * struct vb2_fileio_buf - buffer context used by file io emulator
2128 * vb2 provides a compatibility layer and emulator of file io (read and
2129 * write) calls on top of streaming API. This structure is used for
2130 * tracking context related to the buffers.
2132 struct vb2_fileio_buf {
2136 unsigned int queued:1;
2140 * struct vb2_fileio_data - queue context used by file io emulator
2142 * vb2 provides a compatibility layer and emulator of file io (read and
2143 * write) calls on top of streaming API. For proper operation it required
2144 * this structure to save the driver state between each call of the read
2145 * or write function.
2147 struct vb2_fileio_data {
2148 struct v4l2_requestbuffers req;
2149 struct v4l2_buffer b;
2150 struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME];
2152 unsigned int q_count;
2153 unsigned int dq_count;
2158 * __vb2_init_fileio() - initialize file io emulator
2159 * @q: videobuf2 queue
2160 * @read: mode selector (1 means read, 0 means write)
2162 static int __vb2_init_fileio(struct vb2_queue *q, int read)
2164 struct vb2_fileio_data *fileio;
2166 unsigned int count = 0;
2171 if ((read && !(q->io_modes & VB2_READ)) ||
2172 (!read && !(q->io_modes & VB2_WRITE)))
2176 * Check if device supports mapping buffers to kernel virtual space.
2178 if (!q->mem_ops->vaddr)
2182 * Check if streaming api has not been already activated.
2184 if (q->streaming || q->num_buffers > 0)
2188 * Start with count 1, driver can increase it in queue_setup()
2192 dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n",
2193 (read) ? "read" : "write", count, q->io_flags);
2195 fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL);
2199 fileio->flags = q->io_flags;
2202 * Request buffers and use MMAP type to force driver
2203 * to allocate buffers by itself.
2205 fileio->req.count = count;
2206 fileio->req.memory = V4L2_MEMORY_MMAP;
2207 fileio->req.type = q->type;
2208 ret = vb2_reqbufs(q, &fileio->req);
2213 * Check if plane_count is correct
2214 * (multiplane buffers are not supported).
2216 if (q->bufs[0]->num_planes != 1) {
2222 * Get kernel address of each buffer.
2224 for (i = 0; i < q->num_buffers; i++) {
2225 fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0);
2226 if (fileio->bufs[i].vaddr == NULL) {
2230 fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0);
2234 * Read mode requires pre queuing of all buffers.
2238 * Queue all buffers.
2240 for (i = 0; i < q->num_buffers; i++) {
2241 struct v4l2_buffer *b = &fileio->b;
2242 memset(b, 0, sizeof(*b));
2244 b->memory = q->memory;
2246 ret = vb2_qbuf(q, b);
2249 fileio->bufs[i].queued = 1;
2255 ret = vb2_streamon(q, q->type);
2265 fileio->req.count = 0;
2266 vb2_reqbufs(q, &fileio->req);
2274 * __vb2_cleanup_fileio() - free resourced used by file io emulator
2275 * @q: videobuf2 queue
2277 static int __vb2_cleanup_fileio(struct vb2_queue *q)
2279 struct vb2_fileio_data *fileio = q->fileio;
2283 * Hack fileio context to enable direct calls to vb2 ioctl
2288 vb2_streamoff(q, q->type);
2289 fileio->req.count = 0;
2290 vb2_reqbufs(q, &fileio->req);
2292 dprintk(3, "file io emulator closed\n");
2298 * __vb2_perform_fileio() - perform a single file io (read or write) operation
2299 * @q: videobuf2 queue
2300 * @data: pointed to target userspace buffer
2301 * @count: number of bytes to read or write
2302 * @ppos: file handle position tracking pointer
2303 * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking)
2304 * @read: access mode selector (1 means read, 0 means write)
2306 static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count,
2307 loff_t *ppos, int nonblock, int read)
2309 struct vb2_fileio_data *fileio;
2310 struct vb2_fileio_buf *buf;
2313 dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n",
2314 read ? "read" : "write", (long)*ppos, count,
2315 nonblock ? "non" : "");
2321 * Initialize emulator on first call.
2324 ret = __vb2_init_fileio(q, read);
2325 dprintk(3, "file io: vb2_init_fileio result: %d\n", ret);
2332 * Hack fileio context to enable direct calls to vb2 ioctl interface.
2333 * The pointer will be restored before returning from this function.
2337 index = fileio->index;
2338 buf = &fileio->bufs[index];
2341 * Check if we need to dequeue the buffer.
2344 struct vb2_buffer *vb;
2347 * Call vb2_dqbuf to get buffer back.
2349 memset(&fileio->b, 0, sizeof(fileio->b));
2350 fileio->b.type = q->type;
2351 fileio->b.memory = q->memory;
2352 fileio->b.index = index;
2353 ret = vb2_dqbuf(q, &fileio->b, nonblock);
2354 dprintk(5, "file io: vb2_dqbuf result: %d\n", ret);
2357 fileio->dq_count += 1;
2360 * Get number of bytes filled by the driver
2362 vb = q->bufs[index];
2363 buf->size = vb2_get_plane_payload(vb, 0);
2368 * Limit count on last few bytes of the buffer.
2370 if (buf->pos + count > buf->size) {
2371 count = buf->size - buf->pos;
2372 dprintk(5, "reducing read count: %zd\n", count);
2376 * Transfer data to userspace.
2378 dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n",
2379 count, index, buf->pos);
2381 ret = copy_to_user(data, buf->vaddr + buf->pos, count);
2383 ret = copy_from_user(buf->vaddr + buf->pos, data, count);
2385 dprintk(3, "file io: error copying data\n");
2397 * Queue next buffer if required.
2399 if (buf->pos == buf->size ||
2400 (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) {
2402 * Check if this is the last buffer to read.
2404 if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) &&
2405 fileio->dq_count == 1) {
2406 dprintk(3, "file io: read limit reached\n");
2408 * Restore fileio pointer and release the context.
2411 return __vb2_cleanup_fileio(q);
2415 * Call vb2_qbuf and give buffer to the driver.
2417 memset(&fileio->b, 0, sizeof(fileio->b));
2418 fileio->b.type = q->type;
2419 fileio->b.memory = q->memory;
2420 fileio->b.index = index;
2421 fileio->b.bytesused = buf->pos;
2422 ret = vb2_qbuf(q, &fileio->b);
2423 dprintk(5, "file io: vb2_dbuf result: %d\n", ret);
2428 * Buffer has been queued, update the status
2432 buf->size = q->bufs[0]->v4l2_planes[0].length;
2433 fileio->q_count += 1;
2436 * Switch to the next buffer
2438 fileio->index = (index + 1) % q->num_buffers;
2441 * Start streaming if required.
2443 if (!read && !q->streaming) {
2444 ret = vb2_streamon(q, q->type);
2451 * Return proper number of bytes processed.
2457 * Restore the fileio context and block vb2 ioctl interface.
2463 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
2464 loff_t *ppos, int nonblocking)
2466 return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1);
2468 EXPORT_SYMBOL_GPL(vb2_read);
2470 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
2471 loff_t *ppos, int nonblocking)
2473 return __vb2_perform_fileio(q, (char __user *) data, count,
2474 ppos, nonblocking, 0);
2476 EXPORT_SYMBOL_GPL(vb2_write);
2480 * The following functions are not part of the vb2 core API, but are helper
2481 * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations
2482 * and struct vb2_ops.
2483 * They contain boilerplate code that most if not all drivers have to do
2484 * and so they simplify the driver code.
2487 /* The queue is busy if there is a owner and you are not that owner. */
2488 static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
2490 return vdev->queue->owner && vdev->queue->owner != file->private_data;
2493 /* vb2 ioctl helpers */
2495 int vb2_ioctl_reqbufs(struct file *file, void *priv,
2496 struct v4l2_requestbuffers *p)
2498 struct video_device *vdev = video_devdata(file);
2499 int res = __verify_memory_type(vdev->queue, p->memory, p->type);
2503 if (vb2_queue_is_busy(vdev, file))
2505 res = __reqbufs(vdev->queue, p);
2506 /* If count == 0, then the owner has released all buffers and he
2507 is no longer owner of the queue. Otherwise we have a new owner. */
2509 vdev->queue->owner = p->count ? file->private_data : NULL;
2512 EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs);
2514 int vb2_ioctl_create_bufs(struct file *file, void *priv,
2515 struct v4l2_create_buffers *p)
2517 struct video_device *vdev = video_devdata(file);
2518 int res = __verify_memory_type(vdev->queue, p->memory, p->format.type);
2520 p->index = vdev->queue->num_buffers;
2521 /* If count == 0, then just check if memory and type are valid.
2522 Any -EBUSY result from __verify_memory_type can be mapped to 0. */
2524 return res != -EBUSY ? res : 0;
2527 if (vb2_queue_is_busy(vdev, file))
2529 res = __create_bufs(vdev->queue, p);
2531 vdev->queue->owner = file->private_data;
2534 EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs);
2536 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
2537 struct v4l2_buffer *p)
2539 struct video_device *vdev = video_devdata(file);
2541 if (vb2_queue_is_busy(vdev, file))
2543 return vb2_prepare_buf(vdev->queue, p);
2545 EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf);
2547 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p)
2549 struct video_device *vdev = video_devdata(file);
2551 /* No need to call vb2_queue_is_busy(), anyone can query buffers. */
2552 return vb2_querybuf(vdev->queue, p);
2554 EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf);
2556 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2558 struct video_device *vdev = video_devdata(file);
2560 if (vb2_queue_is_busy(vdev, file))
2562 return vb2_qbuf(vdev->queue, p);
2564 EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf);
2566 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
2568 struct video_device *vdev = video_devdata(file);
2570 if (vb2_queue_is_busy(vdev, file))
2572 return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
2574 EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf);
2576 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
2578 struct video_device *vdev = video_devdata(file);
2580 if (vb2_queue_is_busy(vdev, file))
2582 return vb2_streamon(vdev->queue, i);
2584 EXPORT_SYMBOL_GPL(vb2_ioctl_streamon);
2586 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
2588 struct video_device *vdev = video_devdata(file);
2590 if (vb2_queue_is_busy(vdev, file))
2592 return vb2_streamoff(vdev->queue, i);
2594 EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);
2596 int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
2598 struct video_device *vdev = video_devdata(file);
2600 if (vb2_queue_is_busy(vdev, file))
2602 return vb2_expbuf(vdev->queue, p);
2604 EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf);
2606 /* v4l2_file_operations helpers */
2608 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma)
2610 struct video_device *vdev = video_devdata(file);
2611 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2614 if (lock && mutex_lock_interruptible(lock))
2615 return -ERESTARTSYS;
2616 err = vb2_mmap(vdev->queue, vma);
2621 EXPORT_SYMBOL_GPL(vb2_fop_mmap);
2623 int vb2_fop_release(struct file *file)
2625 struct video_device *vdev = video_devdata(file);
2627 if (file->private_data == vdev->queue->owner) {
2628 vb2_queue_release(vdev->queue);
2629 vdev->queue->owner = NULL;
2631 return v4l2_fh_release(file);
2633 EXPORT_SYMBOL_GPL(vb2_fop_release);
2635 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
2636 size_t count, loff_t *ppos)
2638 struct video_device *vdev = video_devdata(file);
2639 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2642 if (lock && mutex_lock_interruptible(lock))
2643 return -ERESTARTSYS;
2644 if (vb2_queue_is_busy(vdev, file))
2646 err = vb2_write(vdev->queue, buf, count, ppos,
2647 file->f_flags & O_NONBLOCK);
2648 if (vdev->queue->fileio)
2649 vdev->queue->owner = file->private_data;
2655 EXPORT_SYMBOL_GPL(vb2_fop_write);
2657 ssize_t vb2_fop_read(struct file *file, char __user *buf,
2658 size_t count, loff_t *ppos)
2660 struct video_device *vdev = video_devdata(file);
2661 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2664 if (lock && mutex_lock_interruptible(lock))
2665 return -ERESTARTSYS;
2666 if (vb2_queue_is_busy(vdev, file))
2668 err = vb2_read(vdev->queue, buf, count, ppos,
2669 file->f_flags & O_NONBLOCK);
2670 if (vdev->queue->fileio)
2671 vdev->queue->owner = file->private_data;
2677 EXPORT_SYMBOL_GPL(vb2_fop_read);
2679 unsigned int vb2_fop_poll(struct file *file, poll_table *wait)
2681 struct video_device *vdev = video_devdata(file);
2682 struct vb2_queue *q = vdev->queue;
2683 struct mutex *lock = q->lock ? q->lock : vdev->lock;
2684 unsigned long req_events = poll_requested_events(wait);
2687 bool must_lock = false;
2689 /* Try to be smart: only lock if polling might start fileio,
2690 otherwise locking will only introduce unwanted delays. */
2691 if (q->num_buffers == 0 && q->fileio == NULL) {
2692 if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) &&
2693 (req_events & (POLLIN | POLLRDNORM)))
2695 else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) &&
2696 (req_events & (POLLOUT | POLLWRNORM)))
2700 /* If locking is needed, but this helper doesn't know how, then you
2701 shouldn't be using this helper but you should write your own. */
2702 WARN_ON(must_lock && !lock);
2704 if (must_lock && lock && mutex_lock_interruptible(lock))
2709 res = vb2_poll(vdev->queue, file, wait);
2711 /* If fileio was started, then we have a new queue owner. */
2712 if (must_lock && !fileio && q->fileio)
2713 q->owner = file->private_data;
2714 if (must_lock && lock)
2718 EXPORT_SYMBOL_GPL(vb2_fop_poll);
2721 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
2722 unsigned long len, unsigned long pgoff, unsigned long flags)
2724 struct video_device *vdev = video_devdata(file);
2725 struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock;
2728 if (lock && mutex_lock_interruptible(lock))
2729 return -ERESTARTSYS;
2730 ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags);
2735 EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area);
2738 /* vb2_ops helpers. Only use if vq->lock is non-NULL. */
2740 void vb2_ops_wait_prepare(struct vb2_queue *vq)
2742 mutex_unlock(vq->lock);
2744 EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare);
2746 void vb2_ops_wait_finish(struct vb2_queue *vq)
2748 mutex_lock(vq->lock);
2750 EXPORT_SYMBOL_GPL(vb2_ops_wait_finish);
2752 MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2");
2753 MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski");
2754 MODULE_LICENSE("GPL");