1 /*
2  * videobuf2-core.h - V4L2 driver helper framework
3  *
4  * Copyright (C) 2010 Samsung Electronics
5  *
6  * Author: Pawel Osciak <pawel@osciak.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation.
11  */
12 #ifndef _MEDIA_VIDEOBUF2_CORE_H
13 #define _MEDIA_VIDEOBUF2_CORE_H
14 
15 #include <linux/mm_types.h>
16 #include <linux/mutex.h>
17 #include <linux/poll.h>
18 #include <linux/videodev2.h>
19 #include <linux/dma-buf.h>
20 
21 struct vb2_alloc_ctx;
22 struct vb2_fileio_data;
23 struct vb2_threadio_data;
24 
25 /**
26  * struct vb2_mem_ops - memory handling/memory allocator operations
27  * @alloc:	allocate video memory and, optionally, allocator private data,
28  *		return NULL on failure or a pointer to allocator private,
29  *		per-buffer data on success; the returned private structure
30  *		will then be passed as buf_priv argument to other ops in this
31  *		structure. Additional gfp_flags to use when allocating the
32  *		are also passed to this operation. These flags are from the
33  *		gfp_flags field of vb2_queue.
34  * @put:	inform the allocator that the buffer will no longer be used;
35  *		usually will result in the allocator freeing the buffer (if
36  *		no other users of this buffer are present); the buf_priv
37  *		argument is the allocator private per-buffer structure
38  *		previously returned from the alloc callback.
39  * @get_userptr: acquire userspace memory for a hardware operation; used for
40  *		 USERPTR memory types; vaddr is the address passed to the
41  *		 videobuf layer when queuing a video buffer of USERPTR type;
42  *		 should return an allocator private per-buffer structure
43  *		 associated with the buffer on success, NULL on failure;
44  *		 the returned private structure will then be passed as buf_priv
45  *		 argument to other ops in this structure.
46  * @put_userptr: inform the allocator that a USERPTR buffer will no longer
47  *		 be used.
48  * @attach_dmabuf: attach a shared struct dma_buf for a hardware operation;
49  *		   used for DMABUF memory types; alloc_ctx is the alloc context
50  *		   dbuf is the shared dma_buf; returns NULL on failure;
51  *		   allocator private per-buffer structure on success;
52  *		   this needs to be used for further accesses to the buffer.
53  * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
54  *		   buffer is no longer used; the buf_priv argument is the
55  *		   allocator private per-buffer structure previously returned
56  *		   from the attach_dmabuf callback.
57  * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
58  *		of dmabuf is informed that this driver is going to use the
59  *		dmabuf.
60  * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
61  *		  that this driver is done using the dmabuf for now.
62  * @prepare:	called every time the buffer is passed from userspace to the
63  *		driver, useful for cache synchronisation, optional.
64  * @finish:	called every time the buffer is passed back from the driver
65  *		to the userspace, also optional.
66  * @vaddr:	return a kernel virtual address to a given memory buffer
67  *		associated with the passed private structure or NULL if no
68  *		such mapping exists.
69  * @cookie:	return allocator specific cookie for a given memory buffer
70  *		associated with the passed private structure or NULL if not
71  *		available.
72  * @num_users:	return the current number of users of a memory buffer;
73  *		return 1 if the videobuf layer (or actually the driver using
74  *		it) is the only user.
75  * @mmap:	setup a userspace mapping for a given memory buffer under
76  *		the provided virtual memory region.
77  *
78  * Required ops for USERPTR types: get_userptr, put_userptr.
79  * Required ops for MMAP types: alloc, put, num_users, mmap.
80  * Required ops for read/write access types: alloc, put, num_users, vaddr.
81  * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, map_dmabuf,
82  *				  unmap_dmabuf.
83  */
84 struct vb2_mem_ops {
85 	void		*(*alloc)(void *alloc_ctx, unsigned long size, gfp_t gfp_flags);
86 	void		(*put)(void *buf_priv);
87 	struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
88 
89 	void		*(*get_userptr)(void *alloc_ctx, unsigned long vaddr,
90 					unsigned long size, int write);
91 	void		(*put_userptr)(void *buf_priv);
92 
93 	void		(*prepare)(void *buf_priv);
94 	void		(*finish)(void *buf_priv);
95 
96 	void		*(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf,
97 				unsigned long size, int write);
98 	void		(*detach_dmabuf)(void *buf_priv);
99 	int		(*map_dmabuf)(void *buf_priv);
100 	void		(*unmap_dmabuf)(void *buf_priv);
101 
102 	void		*(*vaddr)(void *buf_priv);
103 	void		*(*cookie)(void *buf_priv);
104 
105 	unsigned int	(*num_users)(void *buf_priv);
106 
107 	int		(*mmap)(void *buf_priv, struct vm_area_struct *vma);
108 };
109 
110 struct vb2_plane {
111 	void			*mem_priv;
112 	struct dma_buf		*dbuf;
113 	unsigned int		dbuf_mapped;
114 };
115 
116 /**
117  * enum vb2_io_modes - queue access methods
118  * @VB2_MMAP:		driver supports MMAP with streaming API
119  * @VB2_USERPTR:	driver supports USERPTR with streaming API
120  * @VB2_READ:		driver supports read() style access
121  * @VB2_WRITE:		driver supports write() style access
122  * @VB2_DMABUF:		driver supports DMABUF with streaming API
123  */
124 enum vb2_io_modes {
125 	VB2_MMAP	= (1 << 0),
126 	VB2_USERPTR	= (1 << 1),
127 	VB2_READ	= (1 << 2),
128 	VB2_WRITE	= (1 << 3),
129 	VB2_DMABUF	= (1 << 4),
130 };
131 
132 /**
133  * enum vb2_fileio_flags - flags for selecting a mode of the file io emulator,
134  * by default the 'streaming' style is used by the file io emulator
135  * @VB2_FILEIO_READ_ONCE:	report EOF after reading the first buffer
136  * @VB2_FILEIO_WRITE_IMMEDIATELY:	queue buffer after each write() call
137  */
138 enum vb2_fileio_flags {
139 	VB2_FILEIO_READ_ONCE		= (1 << 0),
140 	VB2_FILEIO_WRITE_IMMEDIATELY	= (1 << 1),
141 };
142 
143 /**
144  * enum vb2_buffer_state - current video buffer state
145  * @VB2_BUF_STATE_DEQUEUED:	buffer under userspace control
146  * @VB2_BUF_STATE_PREPARING:	buffer is being prepared in videobuf
147  * @VB2_BUF_STATE_PREPARED:	buffer prepared in videobuf and by the driver
148  * @VB2_BUF_STATE_QUEUED:	buffer queued in videobuf, but not in driver
149  * @VB2_BUF_STATE_ACTIVE:	buffer queued in driver and possibly used
150  *				in a hardware operation
151  * @VB2_BUF_STATE_DONE:		buffer returned from driver to videobuf, but
152  *				not yet dequeued to userspace
153  * @VB2_BUF_STATE_ERROR:	same as above, but the operation on the buffer
154  *				has ended with an error, which will be reported
155  *				to the userspace when it is dequeued
156  */
157 enum vb2_buffer_state {
158 	VB2_BUF_STATE_DEQUEUED,
159 	VB2_BUF_STATE_PREPARING,
160 	VB2_BUF_STATE_PREPARED,
161 	VB2_BUF_STATE_QUEUED,
162 	VB2_BUF_STATE_ACTIVE,
163 	VB2_BUF_STATE_DONE,
164 	VB2_BUF_STATE_ERROR,
165 };
166 
167 struct vb2_queue;
168 
169 /**
170  * struct vb2_buffer - represents a video buffer
171  * @v4l2_buf:		struct v4l2_buffer associated with this buffer; can
172  *			be read by the driver and relevant entries can be
173  *			changed by the driver in case of CAPTURE types
174  *			(such as timestamp)
175  * @v4l2_planes:	struct v4l2_planes associated with this buffer; can
176  *			be read by the driver and relevant entries can be
177  *			changed by the driver in case of CAPTURE types
178  *			(such as bytesused); NOTE that even for single-planar
179  *			types, the v4l2_planes[0] struct should be used
180  *			instead of v4l2_buf for filling bytesused - drivers
181  *			should use the vb2_set_plane_payload() function for that
182  * @vb2_queue:		the queue to which this driver belongs
183  * @num_planes:		number of planes in the buffer
184  *			on an internal driver queue
185  * @state:		current buffer state; do not change
186  * @queued_entry:	entry on the queued buffers list, which holds all
187  *			buffers queued from userspace
188  * @done_entry:		entry on the list that stores all buffers ready to
189  *			be dequeued to userspace
190  * @planes:		private per-plane information; do not change
191  */
192 struct vb2_buffer {
193 	struct v4l2_buffer	v4l2_buf;
194 	struct v4l2_plane	v4l2_planes[VIDEO_MAX_PLANES];
195 
196 	struct vb2_queue	*vb2_queue;
197 
198 	unsigned int		num_planes;
199 
200 /* Private: internal use only */
201 	enum vb2_buffer_state	state;
202 
203 	struct list_head	queued_entry;
204 	struct list_head	done_entry;
205 
206 	struct vb2_plane	planes[VIDEO_MAX_PLANES];
207 
208 #ifdef CONFIG_VIDEO_ADV_DEBUG
209 	/*
210 	 * Counters for how often these buffer-related ops are
211 	 * called. Used to check for unbalanced ops.
212 	 */
213 	u32		cnt_mem_alloc;
214 	u32		cnt_mem_put;
215 	u32		cnt_mem_get_dmabuf;
216 	u32		cnt_mem_get_userptr;
217 	u32		cnt_mem_put_userptr;
218 	u32		cnt_mem_prepare;
219 	u32		cnt_mem_finish;
220 	u32		cnt_mem_attach_dmabuf;
221 	u32		cnt_mem_detach_dmabuf;
222 	u32		cnt_mem_map_dmabuf;
223 	u32		cnt_mem_unmap_dmabuf;
224 	u32		cnt_mem_vaddr;
225 	u32		cnt_mem_cookie;
226 	u32		cnt_mem_num_users;
227 	u32		cnt_mem_mmap;
228 
229 	u32		cnt_buf_init;
230 	u32		cnt_buf_prepare;
231 	u32		cnt_buf_finish;
232 	u32		cnt_buf_cleanup;
233 	u32		cnt_buf_queue;
234 
235 	/* This counts the number of calls to vb2_buffer_done() */
236 	u32		cnt_buf_done;
237 #endif
238 };
239 
240 /**
241  * struct vb2_ops - driver-specific callbacks
242  *
243  * @queue_setup:	called from VIDIOC_REQBUFS and VIDIOC_CREATE_BUFS
244  *			handlers before memory allocation, or, if
245  *			*num_planes != 0, after the allocation to verify a
246  *			smaller number of buffers. Driver should return
247  *			the required number of buffers in *num_buffers, the
248  *			required number of planes per buffer in *num_planes; the
249  *			size of each plane should be set in the sizes[] array
250  *			and optional per-plane allocator specific context in the
251  *			alloc_ctxs[] array. When called from VIDIOC_REQBUFS,
252  *			fmt == NULL, the driver has to use the currently
253  *			configured format and *num_buffers is the total number
254  *			of buffers, that are being allocated. When called from
255  *			VIDIOC_CREATE_BUFS, fmt != NULL and it describes the
256  *			target frame format (if the format isn't valid the
257  *			callback must return -EINVAL). In this case *num_buffers
258  *			are being allocated additionally to q->num_buffers.
259  * @wait_prepare:	release any locks taken while calling vb2 functions;
260  *			it is called before an ioctl needs to wait for a new
261  *			buffer to arrive; required to avoid a deadlock in
262  *			blocking access type.
263  * @wait_finish:	reacquire all locks released in the previous callback;
264  *			required to continue operation after sleeping while
265  *			waiting for a new buffer to arrive.
266  * @buf_init:		called once after allocating a buffer (in MMAP case)
267  *			or after acquiring a new USERPTR buffer; drivers may
268  *			perform additional buffer-related initialization;
269  *			initialization failure (return != 0) will prevent
270  *			queue setup from completing successfully; optional.
271  * @buf_prepare:	called every time the buffer is queued from userspace
272  *			and from the VIDIOC_PREPARE_BUF ioctl; drivers may
273  *			perform any initialization required before each hardware
274  *			operation in this callback; drivers that support
275  *			VIDIOC_CREATE_BUFS must also validate the buffer size;
276  *			if an error is returned, the buffer will not be queued
277  *			in driver; optional.
278  * @buf_finish:		called before every dequeue of the buffer back to
279  *			userspace; drivers may perform any operations required
280  *			before userspace accesses the buffer; optional. The
281  *			buffer state can be one of the following: DONE and
282  *			ERROR occur while streaming is in progress, and the
283  *			PREPARED state occurs when the queue has been canceled
284  *			and all pending buffers are being returned to their
285  *			default DEQUEUED state. Typically you only have to do
286  *			something if the state is VB2_BUF_STATE_DONE, since in
287  *			all other cases the buffer contents will be ignored
288  *			anyway.
289  * @buf_cleanup:	called once before the buffer is freed; drivers may
290  *			perform any additional cleanup; optional.
291  * @start_streaming:	called once to enter 'streaming' state; the driver may
292  *			receive buffers with @buf_queue callback before
293  *			@start_streaming is called; the driver gets the number
294  *			of already queued buffers in count parameter; driver
295  *			can return an error if hardware fails, in that case all
296  *			buffers that have been already given by the @buf_queue
297  *			callback are to be returned by the driver by calling
298  *			@vb2_buffer_done(VB2_BUF_STATE_DEQUEUED).
299  *			If you need a minimum number of buffers before you can
300  *			start streaming, then set @min_buffers_needed in the
301  *			vb2_queue structure. If that is non-zero then
302  *			start_streaming won't be called until at least that
303  *			many buffers have been queued up by userspace.
304  * @stop_streaming:	called when 'streaming' state must be disabled; driver
305  *			should stop any DMA transactions or wait until they
306  *			finish and give back all buffers it got from buf_queue()
307  *			callback by calling @vb2_buffer_done() with either
308  *			VB2_BUF_STATE_DONE or VB2_BUF_STATE_ERROR; may use
309  *			vb2_wait_for_all_buffers() function
310  * @buf_queue:		passes buffer vb to the driver; driver may start
311  *			hardware operation on this buffer; driver should give
312  *			the buffer back by calling vb2_buffer_done() function;
313  *			it is allways called after calling STREAMON ioctl;
314  *			might be called before start_streaming callback if user
315  *			pre-queued buffers before calling STREAMON.
316  */
317 struct vb2_ops {
318 	int (*queue_setup)(struct vb2_queue *q, const struct v4l2_format *fmt,
319 			   unsigned int *num_buffers, unsigned int *num_planes,
320 			   unsigned int sizes[], void *alloc_ctxs[]);
321 
322 	void (*wait_prepare)(struct vb2_queue *q);
323 	void (*wait_finish)(struct vb2_queue *q);
324 
325 	int (*buf_init)(struct vb2_buffer *vb);
326 	int (*buf_prepare)(struct vb2_buffer *vb);
327 	void (*buf_finish)(struct vb2_buffer *vb);
328 	void (*buf_cleanup)(struct vb2_buffer *vb);
329 
330 	int (*start_streaming)(struct vb2_queue *q, unsigned int count);
331 	void (*stop_streaming)(struct vb2_queue *q);
332 
333 	void (*buf_queue)(struct vb2_buffer *vb);
334 };
335 
336 struct v4l2_fh;
337 
338 /**
339  * struct vb2_queue - a videobuf queue
340  *
341  * @type:	queue type (see V4L2_BUF_TYPE_* in linux/videodev2.h
342  * @io_modes:	supported io methods (see vb2_io_modes enum)
343  * @io_flags:	additional io flags (see vb2_fileio_flags enum)
344  * @lock:	pointer to a mutex that protects the vb2_queue struct. The
345  *		driver can set this to a mutex to let the v4l2 core serialize
346  *		the queuing ioctls. If the driver wants to handle locking
347  *		itself, then this should be set to NULL. This lock is not used
348  *		by the videobuf2 core API.
349  * @owner:	The filehandle that 'owns' the buffers, i.e. the filehandle
350  *		that called reqbufs, create_buffers or started fileio.
351  *		This field is not used by the videobuf2 core API, but it allows
352  *		drivers to easily associate an owner filehandle with the queue.
353  * @ops:	driver-specific callbacks
354  * @mem_ops:	memory allocator specific callbacks
355  * @drv_priv:	driver private data
356  * @buf_struct_size: size of the driver-specific buffer structure;
357  *		"0" indicates the driver doesn't want to use a custom buffer
358  *		structure type, so sizeof(struct vb2_buffer) will is used
359  * @timestamp_flags: Timestamp flags; V4L2_BUF_FLAGS_TIMESTAMP_* and
360  *		V4L2_BUF_FLAGS_TSTAMP_SRC_*
361  * @gfp_flags:	additional gfp flags used when allocating the buffers.
362  *		Typically this is 0, but it may be e.g. GFP_DMA or __GFP_DMA32
363  *		to force the buffer allocation to a specific memory zone.
364  * @min_buffers_needed: the minimum number of buffers needed before
365  *		start_streaming() can be called. Used when a DMA engine
366  *		cannot be started unless at least this number of buffers
367  *		have been queued into the driver.
368  *
369  * @memory:	current memory type used
370  * @bufs:	videobuf buffer structures
371  * @num_buffers: number of allocated/used buffers
372  * @queued_list: list of buffers currently queued from userspace
373  * @queued_count: number of buffers queued and ready for streaming.
374  * @owned_by_drv_count: number of buffers owned by the driver
375  * @done_list:	list of buffers ready to be dequeued to userspace
376  * @done_lock:	lock to protect done_list list
377  * @done_wq:	waitqueue for processes waiting for buffers ready to be dequeued
378  * @alloc_ctx:	memory type/allocator-specific contexts for each plane
379  * @streaming:	current streaming state
380  * @start_streaming_called: start_streaming() was called successfully and we
381  *		started streaming.
382  * @error:	a fatal error occurred on the queue
383  * @fileio:	file io emulator internal data, used only if emulator is active
384  * @threadio:	thread io internal data, used only if thread is active
385  */
386 struct vb2_queue {
387 	enum v4l2_buf_type		type;
388 	unsigned int			io_modes;
389 	unsigned int			io_flags;
390 	struct mutex			*lock;
391 	struct v4l2_fh			*owner;
392 
393 	const struct vb2_ops		*ops;
394 	const struct vb2_mem_ops	*mem_ops;
395 	void				*drv_priv;
396 	unsigned int			buf_struct_size;
397 	u32				timestamp_flags;
398 	gfp_t				gfp_flags;
399 	u32				min_buffers_needed;
400 
401 /* private: internal use only */
402 	enum v4l2_memory		memory;
403 	struct vb2_buffer		*bufs[VIDEO_MAX_FRAME];
404 	unsigned int			num_buffers;
405 
406 	struct list_head		queued_list;
407 	unsigned int			queued_count;
408 
409 	atomic_t			owned_by_drv_count;
410 	struct list_head		done_list;
411 	spinlock_t			done_lock;
412 	wait_queue_head_t		done_wq;
413 
414 	void				*alloc_ctx[VIDEO_MAX_PLANES];
415 	unsigned int			plane_sizes[VIDEO_MAX_PLANES];
416 
417 	unsigned int			streaming:1;
418 	unsigned int			start_streaming_called:1;
419 	unsigned int			error:1;
420 
421 	struct vb2_fileio_data		*fileio;
422 	struct vb2_threadio_data	*threadio;
423 
424 #ifdef CONFIG_VIDEO_ADV_DEBUG
425 	/*
426 	 * Counters for how often these queue-related ops are
427 	 * called. Used to check for unbalanced ops.
428 	 */
429 	u32				cnt_queue_setup;
430 	u32				cnt_wait_prepare;
431 	u32				cnt_wait_finish;
432 	u32				cnt_start_streaming;
433 	u32				cnt_stop_streaming;
434 #endif
435 };
436 
437 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
438 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
439 
440 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
441 void vb2_discard_done(struct vb2_queue *q);
442 int vb2_wait_for_all_buffers(struct vb2_queue *q);
443 
444 int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b);
445 int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req);
446 
447 int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create);
448 int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b);
449 
450 int __must_check vb2_queue_init(struct vb2_queue *q);
451 
452 void vb2_queue_release(struct vb2_queue *q);
453 void vb2_queue_error(struct vb2_queue *q);
454 
455 int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b);
456 int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb);
457 int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);
458 
459 int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type);
460 int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type);
461 
462 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
463 #ifndef CONFIG_MMU
464 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
465 				    unsigned long addr,
466 				    unsigned long len,
467 				    unsigned long pgoff,
468 				    unsigned long flags);
469 #endif
470 unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
471 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
472 		loff_t *ppos, int nonblock);
473 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
474 		loff_t *ppos, int nonblock);
475 /**
476  * vb2_thread_fnc - callback function for use with vb2_thread
477  *
478  * This is called whenever a buffer is dequeued in the thread.
479  */
480 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
481 
482 /**
483  * vb2_thread_start() - start a thread for the given queue.
484  * @q:		videobuf queue
485  * @fnc:	callback function
486  * @priv:	priv pointer passed to the callback function
487  * @thread_name:the name of the thread. This will be prefixed with "vb2-".
488  *
489  * This starts a thread that will queue and dequeue until an error occurs
490  * or @vb2_thread_stop is called.
491  *
492  * This function should not be used for anything else but the videobuf2-dvb
493  * support. If you think you have another good use-case for this, then please
494  * contact the linux-media mailinglist first.
495  */
496 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
497 		     const char *thread_name);
498 
499 /**
500  * vb2_thread_stop() - stop the thread for the given queue.
501  * @q:		videobuf queue
502  */
503 int vb2_thread_stop(struct vb2_queue *q);
504 
505 /**
506  * vb2_is_streaming() - return streaming status of the queue
507  * @q:		videobuf queue
508  */
509 static inline bool vb2_is_streaming(struct vb2_queue *q)
510 {
511 	return q->streaming;
512 }
513 
514 /**
515  * vb2_fileio_is_active() - return true if fileio is active.
516  * @q:		videobuf queue
517  *
518  * This returns true if read() or write() is used to stream the data
519  * as opposed to stream I/O. This is almost never an important distinction,
520  * except in rare cases. One such case is that using read() or write() to
521  * stream a format using V4L2_FIELD_ALTERNATE is not allowed since there
522  * is no way you can pass the field information of each buffer to/from
523  * userspace. A driver that supports this field format should check for
524  * this in the queue_setup op and reject it if this function returns true.
525  */
526 static inline bool vb2_fileio_is_active(struct vb2_queue *q)
527 {
528 	return q->fileio;
529 }
530 
531 /**
532  * vb2_is_busy() - return busy status of the queue
533  * @q:		videobuf queue
534  *
535  * This function checks if queue has any buffers allocated.
536  */
537 static inline bool vb2_is_busy(struct vb2_queue *q)
538 {
539 	return (q->num_buffers > 0);
540 }
541 
542 /**
543  * vb2_get_drv_priv() - return driver private data associated with the queue
544  * @q:		videobuf queue
545  */
546 static inline void *vb2_get_drv_priv(struct vb2_queue *q)
547 {
548 	return q->drv_priv;
549 }
550 
551 /**
552  * vb2_set_plane_payload() - set bytesused for the plane plane_no
553  * @vb:		buffer for which plane payload should be set
554  * @plane_no:	plane number for which payload should be set
555  * @size:	payload in bytes
556  */
557 static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
558 				 unsigned int plane_no, unsigned long size)
559 {
560 	if (plane_no < vb->num_planes)
561 		vb->v4l2_planes[plane_no].bytesused = size;
562 }
563 
564 /**
565  * vb2_get_plane_payload() - get bytesused for the plane plane_no
566  * @vb:		buffer for which plane payload should be set
567  * @plane_no:	plane number for which payload should be set
568  * @size:	payload in bytes
569  */
570 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
571 				 unsigned int plane_no)
572 {
573 	if (plane_no < vb->num_planes)
574 		return vb->v4l2_planes[plane_no].bytesused;
575 	return 0;
576 }
577 
578 /**
579  * vb2_plane_size() - return plane size in bytes
580  * @vb:		buffer for which plane size should be returned
581  * @plane_no:	plane number for which size should be returned
582  */
583 static inline unsigned long
584 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
585 {
586 	if (plane_no < vb->num_planes)
587 		return vb->v4l2_planes[plane_no].length;
588 	return 0;
589 }
590 
591 /*
592  * The following functions are not part of the vb2 core API, but are simple
593  * helper functions that you can use in your struct v4l2_file_operations,
594  * struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
595  * or video_device->lock is set, and they will set and test vb2_queue->owner
596  * to check if the calling filehandle is permitted to do the queuing operation.
597  */
598 
599 /* struct v4l2_ioctl_ops helpers */
600 
601 int vb2_ioctl_reqbufs(struct file *file, void *priv,
602 			  struct v4l2_requestbuffers *p);
603 int vb2_ioctl_create_bufs(struct file *file, void *priv,
604 			  struct v4l2_create_buffers *p);
605 int vb2_ioctl_prepare_buf(struct file *file, void *priv,
606 			  struct v4l2_buffer *p);
607 int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p);
608 int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p);
609 int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p);
610 int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i);
611 int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i);
612 int vb2_ioctl_expbuf(struct file *file, void *priv,
613 	struct v4l2_exportbuffer *p);
614 
615 /* struct v4l2_file_operations helpers */
616 
617 int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma);
618 int vb2_fop_release(struct file *file);
619 int _vb2_fop_release(struct file *file, struct mutex *lock);
620 ssize_t vb2_fop_write(struct file *file, const char __user *buf,
621 		size_t count, loff_t *ppos);
622 ssize_t vb2_fop_read(struct file *file, char __user *buf,
623 		size_t count, loff_t *ppos);
624 unsigned int vb2_fop_poll(struct file *file, poll_table *wait);
625 #ifndef CONFIG_MMU
626 unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr,
627 		unsigned long len, unsigned long pgoff, unsigned long flags);
628 #endif
629 
630 /* struct vb2_ops helpers, only use if vq->lock is non-NULL. */
631 
632 void vb2_ops_wait_prepare(struct vb2_queue *vq);
633 void vb2_ops_wait_finish(struct vb2_queue *vq);
634 
635 #endif /* _MEDIA_VIDEOBUF2_CORE_H */
636