1 /*
2  * videobuf2-core.h - Video Buffer 2 Core 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/dma-buf.h>
19 #include <linux/bitops.h>
20 
21 #define VB2_MAX_FRAME	(32)
22 #define VB2_MAX_PLANES	(8)
23 
24 /**
25  * enum vb2_memory - type of memory model used to make the buffers visible
26  *	on userspace.
27  *
28  * @VB2_MEMORY_UNKNOWN:	Buffer status is unknown or it is not used yet on
29  *			userspace.
30  * @VB2_MEMORY_MMAP:	The buffers are allocated by the Kernel and it is
31  *			memory mapped via mmap() ioctl. This model is
32  *			also used when the user is using the buffers via
33  *			read() or write() system calls.
34  * @VB2_MEMORY_USERPTR:	The buffers was allocated in userspace and it is
35  *			memory mapped via mmap() ioctl.
36  * @VB2_MEMORY_DMABUF:	The buffers are passed to userspace via DMA buffer.
37  */
38 enum vb2_memory {
39 	VB2_MEMORY_UNKNOWN	= 0,
40 	VB2_MEMORY_MMAP		= 1,
41 	VB2_MEMORY_USERPTR	= 2,
42 	VB2_MEMORY_DMABUF	= 4,
43 };
44 
45 struct vb2_fileio_data;
46 struct vb2_threadio_data;
47 
48 /**
49  * struct vb2_mem_ops - memory handling/memory allocator operations.
50  * @alloc:	allocate video memory and, optionally, allocator private data,
51  *		return ERR_PTR() on failure or a pointer to allocator private,
52  *		per-buffer data on success; the returned private structure
53  *		will then be passed as @buf_priv argument to other ops in this
54  *		structure. Additional gfp_flags to use when allocating the
55  *		are also passed to this operation. These flags are from the
56  *		gfp_flags field of vb2_queue.
57  * @put:	inform the allocator that the buffer will no longer be used;
58  *		usually will result in the allocator freeing the buffer (if
59  *		no other users of this buffer are present); the @buf_priv
60  *		argument is the allocator private per-buffer structure
61  *		previously returned from the alloc callback.
62  * @get_dmabuf: acquire userspace memory for a hardware operation; used for
63  *		 DMABUF memory types.
64  * @get_userptr: acquire userspace memory for a hardware operation; used for
65  *		 USERPTR memory types; vaddr is the address passed to the
66  *		 videobuf layer when queuing a video buffer of USERPTR type;
67  *		 should return an allocator private per-buffer structure
68  *		 associated with the buffer on success, ERR_PTR() on failure;
69  *		 the returned private structure will then be passed as @buf_priv
70  *		 argument to other ops in this structure.
71  * @put_userptr: inform the allocator that a USERPTR buffer will no longer
72  *		 be used.
73  * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation;
74  *		   used for DMABUF memory types; dev is the alloc device
75  *		   dbuf is the shared dma_buf; returns ERR_PTR() on failure;
76  *		   allocator private per-buffer structure on success;
77  *		   this needs to be used for further accesses to the buffer.
78  * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF
79  *		   buffer is no longer used; the @buf_priv argument is the
80  *		   allocator private per-buffer structure previously returned
81  *		   from the attach_dmabuf callback.
82  * @map_dmabuf: request for access to the dmabuf from allocator; the allocator
83  *		of dmabuf is informed that this driver is going to use the
84  *		dmabuf.
85  * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified
86  *		  that this driver is done using the dmabuf for now.
87  * @prepare:	called every time the buffer is passed from userspace to the
88  *		driver, useful for cache synchronisation, optional.
89  * @finish:	called every time the buffer is passed back from the driver
90  *		to the userspace, also optional.
91  * @vaddr:	return a kernel virtual address to a given memory buffer
92  *		associated with the passed private structure or NULL if no
93  *		such mapping exists.
94  * @cookie:	return allocator specific cookie for a given memory buffer
95  *		associated with the passed private structure or NULL if not
96  *		available.
97  * @num_users:	return the current number of users of a memory buffer;
98  *		return 1 if the videobuf layer (or actually the driver using
99  *		it) is the only user.
100  * @mmap:	setup a userspace mapping for a given memory buffer under
101  *		the provided virtual memory region.
102  *
103  * Those operations are used by the videobuf2 core to implement the memory
104  * handling/memory allocators for each type of supported streaming I/O method.
105  *
106  * .. note::
107  *    #) Required ops for USERPTR types: get_userptr, put_userptr.
108  *
109  *    #) Required ops for MMAP types: alloc, put, num_users, mmap.
110  *
111  *    #) Required ops for read/write access types: alloc, put, num_users, vaddr.
112  *
113  *    #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf,
114  *       map_dmabuf, unmap_dmabuf.
115  */
116 struct vb2_mem_ops {
117 	void		*(*alloc)(struct device *dev, unsigned long attrs,
118 				  unsigned long size,
119 				  enum dma_data_direction dma_dir,
120 				  gfp_t gfp_flags);
121 	void		(*put)(void *buf_priv);
122 	struct dma_buf *(*get_dmabuf)(void *buf_priv, unsigned long flags);
123 
124 	void		*(*get_userptr)(struct device *dev, unsigned long vaddr,
125 					unsigned long size,
126 					enum dma_data_direction dma_dir);
127 	void		(*put_userptr)(void *buf_priv);
128 
129 	void		(*prepare)(void *buf_priv);
130 	void		(*finish)(void *buf_priv);
131 
132 	void		*(*attach_dmabuf)(struct device *dev,
133 					  struct dma_buf *dbuf,
134 					  unsigned long size,
135 					  enum dma_data_direction dma_dir);
136 	void		(*detach_dmabuf)(void *buf_priv);
137 	int		(*map_dmabuf)(void *buf_priv);
138 	void		(*unmap_dmabuf)(void *buf_priv);
139 
140 	void		*(*vaddr)(void *buf_priv);
141 	void		*(*cookie)(void *buf_priv);
142 
143 	unsigned int	(*num_users)(void *buf_priv);
144 
145 	int		(*mmap)(void *buf_priv, struct vm_area_struct *vma);
146 };
147 
148 /**
149  * struct vb2_plane - plane information.
150  * @mem_priv:	private data with this plane.
151  * @dbuf:	dma_buf - shared buffer object.
152  * @dbuf_mapped:	flag to show whether dbuf is mapped or not
153  * @bytesused:	number of bytes occupied by data in the plane (payload).
154  * @length:	size of this plane (NOT the payload) in bytes.
155  * @min_length:	minimum required size of this plane (NOT the payload) in bytes.
156  *		@length is always greater or equal to @min_length.
157  * @m:		Union with memtype-specific data.
158  * @m.offset:	when memory in the associated struct vb2_buffer is
159  *		%VB2_MEMORY_MMAP, equals the offset from the start of
160  *		the device memory for this plane (or is a "cookie" that
161  *		should be passed to mmap() called on the video node).
162  * @m.userptr:	when memory is %VB2_MEMORY_USERPTR, a userspace pointer
163  *		pointing to this plane.
164  * @m.fd:	when memory is %VB2_MEMORY_DMABUF, a userspace file
165  *		descriptor associated with this plane.
166  * @data_offset:	offset in the plane to the start of data; usually 0,
167  *		unless there is a header in front of the data.
168  *
169  * Should contain enough information to be able to cover all the fields
170  * of &struct v4l2_plane at videodev2.h.
171  */
172 struct vb2_plane {
173 	void			*mem_priv;
174 	struct dma_buf		*dbuf;
175 	unsigned int		dbuf_mapped;
176 	unsigned int		bytesused;
177 	unsigned int		length;
178 	unsigned int		min_length;
179 	union {
180 		unsigned int	offset;
181 		unsigned long	userptr;
182 		int		fd;
183 	} m;
184 	unsigned int		data_offset;
185 };
186 
187 /**
188  * enum vb2_io_modes - queue access methods.
189  * @VB2_MMAP:		driver supports MMAP with streaming API.
190  * @VB2_USERPTR:	driver supports USERPTR with streaming API.
191  * @VB2_READ:		driver supports read() style access.
192  * @VB2_WRITE:		driver supports write() style access.
193  * @VB2_DMABUF:		driver supports DMABUF with streaming API.
194  */
195 enum vb2_io_modes {
196 	VB2_MMAP	= BIT(0),
197 	VB2_USERPTR	= BIT(1),
198 	VB2_READ	= BIT(2),
199 	VB2_WRITE	= BIT(3),
200 	VB2_DMABUF	= BIT(4),
201 };
202 
203 /**
204  * enum vb2_buffer_state - current video buffer state.
205  * @VB2_BUF_STATE_DEQUEUED:	buffer under userspace control.
206  * @VB2_BUF_STATE_PREPARING:	buffer is being prepared in videobuf.
207  * @VB2_BUF_STATE_PREPARED:	buffer prepared in videobuf and by the driver.
208  * @VB2_BUF_STATE_QUEUED:	buffer queued in videobuf, but not in driver.
209  * @VB2_BUF_STATE_REQUEUEING:	re-queue a buffer to the driver.
210  * @VB2_BUF_STATE_ACTIVE:	buffer queued in driver and possibly used
211  *				in a hardware operation.
212  * @VB2_BUF_STATE_DONE:		buffer returned from driver to videobuf, but
213  *				not yet dequeued to userspace.
214  * @VB2_BUF_STATE_ERROR:	same as above, but the operation on the buffer
215  *				has ended with an error, which will be reported
216  *				to the userspace when it is dequeued.
217  */
218 enum vb2_buffer_state {
219 	VB2_BUF_STATE_DEQUEUED,
220 	VB2_BUF_STATE_PREPARING,
221 	VB2_BUF_STATE_PREPARED,
222 	VB2_BUF_STATE_QUEUED,
223 	VB2_BUF_STATE_REQUEUEING,
224 	VB2_BUF_STATE_ACTIVE,
225 	VB2_BUF_STATE_DONE,
226 	VB2_BUF_STATE_ERROR,
227 };
228 
229 struct vb2_queue;
230 
231 /**
232  * struct vb2_buffer - represents a video buffer.
233  * @vb2_queue:		pointer to &struct vb2_queue with the queue to
234  *			which this driver belongs.
235  * @index:		id number of the buffer.
236  * @type:		buffer type.
237  * @memory:		the method, in which the actual data is passed.
238  * @num_planes:		number of planes in the buffer
239  *			on an internal driver queue.
240  * @timestamp:		frame timestamp in ns.
241  */
242 struct vb2_buffer {
243 	struct vb2_queue	*vb2_queue;
244 	unsigned int		index;
245 	unsigned int		type;
246 	unsigned int		memory;
247 	unsigned int		num_planes;
248 	u64			timestamp;
249 
250 	/* private: internal use only
251 	 *
252 	 * state:		current buffer state; do not change
253 	 * queued_entry:	entry on the queued buffers list, which holds
254 	 *			all buffers queued from userspace
255 	 * done_entry:		entry on the list that stores all buffers ready
256 	 *			to be dequeued to userspace
257 	 * vb2_plane:		per-plane information; do not change
258 	 */
259 	enum vb2_buffer_state	state;
260 
261 	struct vb2_plane	planes[VB2_MAX_PLANES];
262 	struct list_head	queued_entry;
263 	struct list_head	done_entry;
264 #ifdef CONFIG_VIDEO_ADV_DEBUG
265 	/*
266 	 * Counters for how often these buffer-related ops are
267 	 * called. Used to check for unbalanced ops.
268 	 */
269 	u32		cnt_mem_alloc;
270 	u32		cnt_mem_put;
271 	u32		cnt_mem_get_dmabuf;
272 	u32		cnt_mem_get_userptr;
273 	u32		cnt_mem_put_userptr;
274 	u32		cnt_mem_prepare;
275 	u32		cnt_mem_finish;
276 	u32		cnt_mem_attach_dmabuf;
277 	u32		cnt_mem_detach_dmabuf;
278 	u32		cnt_mem_map_dmabuf;
279 	u32		cnt_mem_unmap_dmabuf;
280 	u32		cnt_mem_vaddr;
281 	u32		cnt_mem_cookie;
282 	u32		cnt_mem_num_users;
283 	u32		cnt_mem_mmap;
284 
285 	u32		cnt_buf_init;
286 	u32		cnt_buf_prepare;
287 	u32		cnt_buf_finish;
288 	u32		cnt_buf_cleanup;
289 	u32		cnt_buf_queue;
290 
291 	/* This counts the number of calls to vb2_buffer_done() */
292 	u32		cnt_buf_done;
293 #endif
294 };
295 
296 /**
297  * struct vb2_ops - driver-specific callbacks.
298  *
299  * These operations are not called from interrupt context except where
300  * mentioned specifically.
301  *
302  * @queue_setup:	called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS()
303  *			handlers before memory allocation. It can be called
304  *			twice: if the original number of requested buffers
305  *			could not be allocated, then it will be called a
306  *			second time with the actually allocated number of
307  *			buffers to verify if that is OK.
308  *			The driver should return the required number of buffers
309  *			in \*num_buffers, the required number of planes per
310  *			buffer in \*num_planes, the size of each plane should be
311  *			set in the sizes\[\] array and optional per-plane
312  *			allocator specific device in the alloc_devs\[\] array.
313  *			When called from VIDIOC_REQBUFS(), \*num_planes == 0,
314  *			the driver has to use the currently configured format to
315  *			determine the plane sizes and \*num_buffers is the total
316  *			number of buffers that are being allocated. When called
317  *			from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it
318  *			describes the requested number of planes and sizes\[\]
319  *			contains the requested plane sizes. In this case
320  *			\*num_buffers are being allocated additionally to
321  *			q->num_buffers. If either \*num_planes or the requested
322  *			sizes are invalid callback must return %-EINVAL.
323  * @wait_prepare:	release any locks taken while calling vb2 functions;
324  *			it is called before an ioctl needs to wait for a new
325  *			buffer to arrive; required to avoid a deadlock in
326  *			blocking access type.
327  * @wait_finish:	reacquire all locks released in the previous callback;
328  *			required to continue operation after sleeping while
329  *			waiting for a new buffer to arrive.
330  * @buf_init:		called once after allocating a buffer (in MMAP case)
331  *			or after acquiring a new USERPTR buffer; drivers may
332  *			perform additional buffer-related initialization;
333  *			initialization failure (return != 0) will prevent
334  *			queue setup from completing successfully; optional.
335  * @buf_prepare:	called every time the buffer is queued from userspace
336  *			and from the VIDIOC_PREPARE_BUF() ioctl; drivers may
337  *			perform any initialization required before each
338  *			hardware operation in this callback; drivers can
339  *			access/modify the buffer here as it is still synced for
340  *			the CPU; drivers that support VIDIOC_CREATE_BUFS() must
341  *			also validate the buffer size; if an error is returned,
342  *			the buffer will not be queued in driver; optional.
343  * @buf_finish:		called before every dequeue of the buffer back to
344  *			userspace; the buffer is synced for the CPU, so drivers
345  *			can access/modify the buffer contents; drivers may
346  *			perform any operations required before userspace
347  *			accesses the buffer; optional. The buffer state can be
348  *			one of the following: %DONE and %ERROR occur while
349  *			streaming is in progress, and the %PREPARED state occurs
350  *			when the queue has been canceled and all pending
351  *			buffers are being returned to their default %DEQUEUED
352  *			state. Typically you only have to do something if the
353  *			state is %VB2_BUF_STATE_DONE, since in all other cases
354  *			the buffer contents will be ignored anyway.
355  * @buf_cleanup:	called once before the buffer is freed; drivers may
356  *			perform any additional cleanup; optional.
357  * @start_streaming:	called once to enter 'streaming' state; the driver may
358  *			receive buffers with @buf_queue callback
359  *			before @start_streaming is called; the driver gets the
360  *			number of already queued buffers in count parameter;
361  *			driver can return an error if hardware fails, in that
362  *			case all buffers that have been already given by
363  *			the @buf_queue callback are to be returned by the driver
364  *			by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED
365  *			or %VB2_BUF_STATE_REQUEUEING. If you need a minimum
366  *			number of buffers before you can start streaming, then
367  *			set &vb2_queue->min_buffers_needed. If that is non-zero
368  *			then @start_streaming won't be called until at least
369  *			that many buffers have been queued up by userspace.
370  * @stop_streaming:	called when 'streaming' state must be disabled; driver
371  *			should stop any DMA transactions or wait until they
372  *			finish and give back all buffers it got from &buf_queue
373  *			callback by calling vb2_buffer_done() with either
374  *			%VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use
375  *			vb2_wait_for_all_buffers() function
376  * @buf_queue:		passes buffer vb to the driver; driver may start
377  *			hardware operation on this buffer; driver should give
378  *			the buffer back by calling vb2_buffer_done() function;
379  *			it is allways called after calling VIDIOC_STREAMON()
380  *			ioctl; might be called before @start_streaming callback
381  *			if user pre-queued buffers before calling
382  *			VIDIOC_STREAMON().
383  */
384 struct vb2_ops {
385 	int (*queue_setup)(struct vb2_queue *q,
386 			   unsigned int *num_buffers, unsigned int *num_planes,
387 			   unsigned int sizes[], struct device *alloc_devs[]);
388 
389 	void (*wait_prepare)(struct vb2_queue *q);
390 	void (*wait_finish)(struct vb2_queue *q);
391 
392 	int (*buf_init)(struct vb2_buffer *vb);
393 	int (*buf_prepare)(struct vb2_buffer *vb);
394 	void (*buf_finish)(struct vb2_buffer *vb);
395 	void (*buf_cleanup)(struct vb2_buffer *vb);
396 
397 	int (*start_streaming)(struct vb2_queue *q, unsigned int count);
398 	void (*stop_streaming)(struct vb2_queue *q);
399 
400 	void (*buf_queue)(struct vb2_buffer *vb);
401 };
402 
403 /**
404  * struct vb2_buf_ops - driver-specific callbacks.
405  *
406  * @verify_planes_array: Verify that a given user space structure contains
407  *			enough planes for the buffer. This is called
408  *			for each dequeued buffer.
409  * @fill_user_buffer:	given a &vb2_buffer fill in the userspace structure.
410  *			For V4L2 this is a &struct v4l2_buffer.
411  * @fill_vb2_buffer:	given a userspace structure, fill in the &vb2_buffer.
412  *			If the userspace structure is invalid, then this op
413  *			will return an error.
414  * @copy_timestamp:	copy the timestamp from a userspace structure to
415  *			the &struct vb2_buffer.
416  */
417 struct vb2_buf_ops {
418 	int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
419 	void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
420 	int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
421 				struct vb2_plane *planes);
422 	void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
423 };
424 
425 /**
426  * struct vb2_queue - a videobuf queue.
427  *
428  * @type:	private buffer type whose content is defined by the vb2-core
429  *		caller. For example, for V4L2, it should match
430  *		the types defined on &enum v4l2_buf_type.
431  * @io_modes:	supported io methods (see &enum vb2_io_modes).
432  * @alloc_devs:	&struct device memory type/allocator-specific per-plane device
433  * @dev:	device to use for the default allocation context if the driver
434  *		doesn't fill in the @alloc_devs array.
435  * @dma_attrs:	DMA attributes to use for the DMA.
436  * @bidirectional: when this flag is set the DMA direction for the buffers of
437  *		this queue will be overridden with %DMA_BIDIRECTIONAL direction.
438  *		This is useful in cases where the hardware (firmware) writes to
439  *		a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from
440  *		buffer which is mapped for write (%DMA_FROM_DEVICE) in order
441  *		to satisfy some internal hardware restrictions or adds a padding
442  *		needed by the processing algorithm. In case the DMA mapping is
443  *		not bidirectional but the hardware (firmware) trying to access
444  *		the buffer (in the opposite direction) this could lead to an
445  *		IOMMU protection faults.
446  * @fileio_read_once:		report EOF after reading the first buffer
447  * @fileio_write_immediately:	queue buffer after each write() call
448  * @allow_zero_bytesused:	allow bytesused == 0 to be passed to the driver
449  * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF
450  *              has not been called. This is a vb1 idiom that has been adopted
451  *              also by vb2.
452  * @lock:	pointer to a mutex that protects the &struct vb2_queue. The
453  *		driver can set this to a mutex to let the v4l2 core serialize
454  *		the queuing ioctls. If the driver wants to handle locking
455  *		itself, then this should be set to NULL. This lock is not used
456  *		by the videobuf2 core API.
457  * @owner:	The filehandle that 'owns' the buffers, i.e. the filehandle
458  *		that called reqbufs, create_buffers or started fileio.
459  *		This field is not used by the videobuf2 core API, but it allows
460  *		drivers to easily associate an owner filehandle with the queue.
461  * @ops:	driver-specific callbacks
462  * @mem_ops:	memory allocator specific callbacks
463  * @buf_ops:	callbacks to deliver buffer information.
464  *		between user-space and kernel-space.
465  * @drv_priv:	driver private data.
466  * @buf_struct_size: size of the driver-specific buffer structure;
467  *		"0" indicates the driver doesn't want to use a custom buffer
468  *		structure type. for example, ``sizeof(struct vb2_v4l2_buffer)``
469  *		will be used for v4l2.
470  * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and
471  *		``V4L2_BUF_FLAG_TSTAMP_SRC_*``
472  * @gfp_flags:	additional gfp flags used when allocating the buffers.
473  *		Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32
474  *		to force the buffer allocation to a specific memory zone.
475  * @min_buffers_needed: the minimum number of buffers needed before
476  *		@start_streaming can be called. Used when a DMA engine
477  *		cannot be started unless at least this number of buffers
478  *		have been queued into the driver.
479  */
480 /*
481  * Private elements (won't appear at the uAPI book):
482  * @mmap_lock:	private mutex used when buffers are allocated/freed/mmapped
483  * @memory:	current memory type used
484  * @dma_dir:	DMA mapping direction.
485  * @bufs:	videobuf buffer structures
486  * @num_buffers: number of allocated/used buffers
487  * @queued_list: list of buffers currently queued from userspace
488  * @queued_count: number of buffers queued and ready for streaming.
489  * @owned_by_drv_count: number of buffers owned by the driver
490  * @done_list:	list of buffers ready to be dequeued to userspace
491  * @done_lock:	lock to protect done_list list
492  * @done_wq:	waitqueue for processes waiting for buffers ready to be dequeued
493  * @streaming:	current streaming state
494  * @start_streaming_called: @start_streaming was called successfully and we
495  *		started streaming.
496  * @error:	a fatal error occurred on the queue
497  * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for
498  *		buffers. Only set for capture queues if qbuf has not yet been
499  *		called since poll() needs to return %EPOLLERR in that situation.
500  * @is_multiplanar: set if buffer type is multiplanar
501  * @is_output:	set if buffer type is output
502  * @copy_timestamp: set if vb2-core should set timestamps
503  * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the
504  *		last decoded buffer was already dequeued. Set for capture queues
505  *		when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued.
506  * @fileio:	file io emulator internal data, used only if emulator is active
507  * @threadio:	thread io internal data, used only if thread is active
508  */
509 struct vb2_queue {
510 	unsigned int			type;
511 	unsigned int			io_modes;
512 	struct device			*dev;
513 	unsigned long			dma_attrs;
514 	unsigned			bidirectional:1;
515 	unsigned			fileio_read_once:1;
516 	unsigned			fileio_write_immediately:1;
517 	unsigned			allow_zero_bytesused:1;
518 	unsigned		   quirk_poll_must_check_waiting_for_buffers:1;
519 
520 	struct mutex			*lock;
521 	void				*owner;
522 
523 	const struct vb2_ops		*ops;
524 	const struct vb2_mem_ops	*mem_ops;
525 	const struct vb2_buf_ops	*buf_ops;
526 
527 	void				*drv_priv;
528 	unsigned int			buf_struct_size;
529 	u32				timestamp_flags;
530 	gfp_t				gfp_flags;
531 	u32				min_buffers_needed;
532 
533 	struct device			*alloc_devs[VB2_MAX_PLANES];
534 
535 	/* private: internal use only */
536 	struct mutex			mmap_lock;
537 	unsigned int			memory;
538 	enum dma_data_direction		dma_dir;
539 	struct vb2_buffer		*bufs[VB2_MAX_FRAME];
540 	unsigned int			num_buffers;
541 
542 	struct list_head		queued_list;
543 	unsigned int			queued_count;
544 
545 	atomic_t			owned_by_drv_count;
546 	struct list_head		done_list;
547 	spinlock_t			done_lock;
548 	wait_queue_head_t		done_wq;
549 
550 	unsigned int			streaming:1;
551 	unsigned int			start_streaming_called:1;
552 	unsigned int			error:1;
553 	unsigned int			waiting_for_buffers:1;
554 	unsigned int			waiting_in_dqbuf:1;
555 	unsigned int			is_multiplanar:1;
556 	unsigned int			is_output:1;
557 	unsigned int			copy_timestamp:1;
558 	unsigned int			last_buffer_dequeued:1;
559 
560 	struct vb2_fileio_data		*fileio;
561 	struct vb2_threadio_data	*threadio;
562 
563 #ifdef CONFIG_VIDEO_ADV_DEBUG
564 	/*
565 	 * Counters for how often these queue-related ops are
566 	 * called. Used to check for unbalanced ops.
567 	 */
568 	u32				cnt_queue_setup;
569 	u32				cnt_wait_prepare;
570 	u32				cnt_wait_finish;
571 	u32				cnt_start_streaming;
572 	u32				cnt_stop_streaming;
573 #endif
574 };
575 
576 /**
577  * vb2_plane_vaddr() - Return a kernel virtual address of a given plane.
578  * @vb:		pointer to &struct vb2_buffer to which the plane in
579  *		question belongs to.
580  * @plane_no:	plane number for which the address is to be returned.
581  *
582  * This function returns a kernel virtual address of a given plane if
583  * such a mapping exist, NULL otherwise.
584  */
585 void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no);
586 
587 /**
588  * vb2_plane_cookie() - Return allocator specific cookie for the given plane.
589  * @vb:		pointer to &struct vb2_buffer to which the plane in
590  *		question belongs to.
591  * @plane_no:	plane number for which the cookie is to be returned.
592  *
593  * This function returns an allocator specific cookie for a given plane if
594  * available, NULL otherwise. The allocator should provide some simple static
595  * inline function, which would convert this cookie to the allocator specific
596  * type that can be used directly by the driver to access the buffer. This can
597  * be for example physical address, pointer to scatter list or IOMMU mapping.
598  */
599 void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no);
600 
601 /**
602  * vb2_buffer_done() - inform videobuf that an operation on a buffer
603  *	is finished.
604  * @vb:		pointer to &struct vb2_buffer to be used.
605  * @state:	state of the buffer, as defined by &enum vb2_buffer_state.
606  *		Either %VB2_BUF_STATE_DONE if the operation finished
607  *		successfully, %VB2_BUF_STATE_ERROR if the operation finished
608  *		with an error or any of %VB2_BUF_STATE_QUEUED or
609  *		%VB2_BUF_STATE_REQUEUEING if the driver wants to
610  *		requeue buffers (see below).
611  *
612  * This function should be called by the driver after a hardware operation on
613  * a buffer is finished and the buffer may be returned to userspace. The driver
614  * cannot use this buffer anymore until it is queued back to it by videobuf
615  * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued
616  * to the driver by &vb2_ops->buf_queue can be passed to this function.
617  *
618  * While streaming a buffer can only be returned in state DONE or ERROR.
619  * The &vb2_ops->start_streaming op can also return them in case the DMA engine
620  * cannot be started for some reason. In that case the buffers should be
621  * returned with state QUEUED or REQUEUEING to put them back into the queue.
622  *
623  * %VB2_BUF_STATE_REQUEUEING is like %VB2_BUF_STATE_QUEUED, but it also calls
624  * &vb2_ops->buf_queue to queue buffers back to the driver. Note that calling
625  * vb2_buffer_done(..., VB2_BUF_STATE_REQUEUEING) from interrupt context will
626  * result in &vb2_ops->buf_queue being called in interrupt context as well.
627  */
628 void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state);
629 
630 /**
631  * vb2_discard_done() - discard all buffers marked as DONE.
632  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
633  *
634  * This function is intended to be used with suspend/resume operations. It
635  * discards all 'done' buffers as they would be too old to be requested after
636  * resume.
637  *
638  * Drivers must stop the hardware and synchronize with interrupt handlers and/or
639  * delayed works before calling this function to make sure no buffer will be
640  * touched by the driver and/or hardware.
641  */
642 void vb2_discard_done(struct vb2_queue *q);
643 
644 /**
645  * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2.
646  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
647  *
648  * This function will wait until all buffers that have been given to the driver
649  * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It
650  * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair.
651  * It is intended to be called with all locks taken, for example from
652  * &vb2_ops->stop_streaming callback.
653  */
654 int vb2_wait_for_all_buffers(struct vb2_queue *q);
655 
656 /**
657  * vb2_core_querybuf() - query video buffer information.
658  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
659  * @index:	id number of the buffer.
660  * @pb:		buffer struct passed from userspace.
661  *
662  * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called
663  * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
664  *
665  * The passed buffer should have been verified.
666  *
667  * This function fills the relevant information for the userspace.
668  *
669  * Return: returns zero on success; an error code otherwise.
670  */
671 void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
672 
673 /**
674  * vb2_core_reqbufs() - Initiate streaming.
675  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
676  * @memory:	memory type, as defined by &enum vb2_memory.
677  * @count:	requested buffer count.
678  *
679  * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
680  * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
681  *
682  * This function:
683  *
684  * #) verifies streaming parameters passed from the userspace;
685  * #) sets up the queue;
686  * #) negotiates number of buffers and planes per buffer with the driver
687  *    to be used during streaming;
688  * #) allocates internal buffer structures (&struct vb2_buffer), according to
689  *    the agreed parameters;
690  * #) for MMAP memory type, allocates actual video memory, using the
691  *    memory handling/allocation routines provided during queue initialization.
692  *
693  * If req->count is 0, all the memory will be freed instead.
694  *
695  * If the queue has been allocated previously by a previous vb2_core_reqbufs()
696  * call and the queue is not busy, memory will be reallocated.
697  *
698  * Return: returns zero on success; an error code otherwise.
699  */
700 int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
701 		unsigned int *count);
702 
703 /**
704  * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
705  * @q: pointer to &struct vb2_queue with videobuf2 queue.
706  * @memory: memory type, as defined by &enum vb2_memory.
707  * @count: requested buffer count.
708  * @requested_planes: number of planes requested.
709  * @requested_sizes: array with the size of the planes.
710  *
711  * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is
712  * called internally by VB2 by an API-specific handler, like
713  * ``videobuf2-v4l2.h``.
714  *
715  * This function:
716  *
717  * #) verifies parameter sanity;
718  * #) calls the &vb2_ops->queue_setup queue operation;
719  * #) performs any necessary memory allocations.
720  *
721  * Return: returns zero on success; an error code otherwise.
722  */
723 int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
724 			 unsigned int *count, unsigned int requested_planes,
725 			 const unsigned int requested_sizes[]);
726 
727 /**
728  * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace
729  *			to the kernel.
730  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
731  * @index:	id number of the buffer.
732  * @pb:		buffer structure passed from userspace to
733  *		&v4l2_ioctl_ops->vidioc_prepare_buf handler in driver.
734  *
735  * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is
736  * called internally by VB2 by an API-specific handler, like
737  * ``videobuf2-v4l2.h``.
738  *
739  * The passed buffer should have been verified.
740  *
741  * This function calls vb2_ops->buf_prepare callback in the driver
742  * (if provided), in which driver-specific buffer initialization can
743  * be performed.
744  *
745  * Return: returns zero on success; an error code otherwise.
746  */
747 int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb);
748 
749 /**
750  * vb2_core_qbuf() - Queue a buffer from userspace
751  *
752  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
753  * @index:	id number of the buffer
754  * @pb:		buffer structure passed from userspace to
755  *		v4l2_ioctl_ops->vidioc_qbuf handler in driver
756  *
757  * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called
758  * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
759  *
760  * This function:
761  *
762  * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver
763  *    (if provided), in which driver-specific buffer initialization can
764  *    be performed;
765  * #) if streaming is on, queues the buffer in driver by the means of
766  *    &vb2_ops->buf_queue callback for processing.
767  *
768  * Return: returns zero on success; an error code otherwise.
769  */
770 int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb);
771 
772 /**
773  * vb2_core_dqbuf() - Dequeue a buffer to the userspace
774  * @q:		pointer to &struct vb2_queue with videobuf2 queue
775  * @pindex:	pointer to the buffer index. May be NULL
776  * @pb:		buffer structure passed from userspace to
777  *		v4l2_ioctl_ops->vidioc_dqbuf handler in driver.
778  * @nonblocking: if true, this call will not sleep waiting for a buffer if no
779  *		 buffers ready for dequeuing are present. Normally the driver
780  *		 would be passing (file->f_flags & O_NONBLOCK) here.
781  *
782  * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called
783  * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
784  *
785  * This function:
786  *
787  * #) calls buf_finish callback in the driver (if provided), in which
788  *    driver can perform any additional operations that may be required before
789  *    returning the buffer to userspace, such as cache sync,
790  * #) the buffer struct members are filled with relevant information for
791  *    the userspace.
792  *
793  * Return: returns zero on success; an error code otherwise.
794  */
795 int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb,
796 		   bool nonblocking);
797 
798 /**
799  * vb2_core_streamon() - Implements VB2 stream ON logic
800  *
801  * @q:		pointer to &struct vb2_queue with videobuf2 queue
802  * @type:	type of the queue to be started.
803  *		For V4L2, this is defined by &enum v4l2_buf_type type.
804  *
805  * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called
806  * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
807  *
808  * Return: returns zero on success; an error code otherwise.
809  */
810 int vb2_core_streamon(struct vb2_queue *q, unsigned int type);
811 
812 /**
813  * vb2_core_streamoff() - Implements VB2 stream OFF logic
814  *
815  * @q:		pointer to &struct vb2_queue with videobuf2 queue
816  * @type:	type of the queue to be started.
817  *		For V4L2, this is defined by &enum v4l2_buf_type type.
818  *
819  * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is
820  * called internally by VB2 by an API-specific handler, like
821  * ``videobuf2-v4l2.h``.
822  *
823  * Return: returns zero on success; an error code otherwise.
824  */
825 int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
826 
827 /**
828  * vb2_core_expbuf() - Export a buffer as a file descriptor.
829  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
830  * @fd:		pointer to the file descriptor associated with DMABUF
831  *		(set by driver).
832  * @type:	buffer type.
833  * @index:	id number of the buffer.
834  * @plane:	index of the plane to be exported, 0 for single plane queues
835  * @flags:	file flags for newly created file, as defined at
836  *		include/uapi/asm-generic/fcntl.h.
837  *		Currently, the only used flag is %O_CLOEXEC.
838  *		is supported, refer to manual of open syscall for more details.
839  *
840  *
841  * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called
842  * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``.
843  *
844  * Return: returns zero on success; an error code otherwise.
845  */
846 int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
847 		unsigned int index, unsigned int plane, unsigned int flags);
848 
849 /**
850  * vb2_core_queue_init() - initialize a videobuf2 queue
851  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
852  *		This structure should be allocated in driver
853  *
854  * The &vb2_queue structure should be allocated by the driver. The driver is
855  * responsible of clearing it's content and setting initial values for some
856  * required entries before calling this function.
857  *
858  * .. note::
859  *
860  *    The following fields at @q should be set before calling this function:
861  *    &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type.
862  */
863 int vb2_core_queue_init(struct vb2_queue *q);
864 
865 /**
866  * vb2_core_queue_release() - stop streaming, release the queue and free memory
867  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
868  *
869  * This function stops streaming and performs necessary clean ups, including
870  * freeing video buffer memory. The driver is responsible for freeing
871  * the &struct vb2_queue itself.
872  */
873 void vb2_core_queue_release(struct vb2_queue *q);
874 
875 /**
876  * vb2_queue_error() - signal a fatal error on the queue
877  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
878  *
879  * Flag that a fatal unrecoverable error has occurred and wake up all processes
880  * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing
881  * buffers will return %-EIO.
882  *
883  * The error flag will be cleared when canceling the queue, either from
884  * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this
885  * function before starting the stream, otherwise the error flag will remain set
886  * until the queue is released when closing the device node.
887  */
888 void vb2_queue_error(struct vb2_queue *q);
889 
890 /**
891  * vb2_mmap() - map video buffers into application address space.
892  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
893  * @vma:	pointer to &struct vm_area_struct with the vma passed
894  *		to the mmap file operation handler in the driver.
895  *
896  * Should be called from mmap file operation handler of a driver.
897  * This function maps one plane of one of the available video buffers to
898  * userspace. To map whole video memory allocated on reqbufs, this function
899  * has to be called once per each plane per each buffer previously allocated.
900  *
901  * When the userspace application calls mmap, it passes to it an offset returned
902  * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler.
903  * That offset acts as a "cookie", which is then used to identify the plane
904  * to be mapped.
905  *
906  * This function finds a plane with a matching offset and a mapping is performed
907  * by the means of a provided memory operation.
908  *
909  * The return values from this function are intended to be directly returned
910  * from the mmap handler in driver.
911  */
912 int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma);
913 
914 #ifndef CONFIG_MMU
915 /**
916  * vb2_get_unmapped_area - map video buffers into application address space.
917  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
918  * @addr:	memory address.
919  * @len:	buffer size.
920  * @pgoff:	page offset.
921  * @flags:	memory flags.
922  *
923  * This function is used in noMMU platforms to propose address mapping
924  * for a given buffer. It's intended to be used as a handler for the
925  * &file_operations->get_unmapped_area operation.
926  *
927  * This is called by the mmap() syscall routines will call this
928  * to get a proposed address for the mapping, when ``!CONFIG_MMU``.
929  */
930 unsigned long vb2_get_unmapped_area(struct vb2_queue *q,
931 				    unsigned long addr,
932 				    unsigned long len,
933 				    unsigned long pgoff,
934 				    unsigned long flags);
935 #endif
936 
937 /**
938  * vb2_core_poll() - implements poll syscall() logic.
939  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
940  * @file:	&struct file argument passed to the poll
941  *		file operation handler.
942  * @wait:	&poll_table wait argument passed to the poll
943  *		file operation handler.
944  *
945  * This function implements poll file operation handler for a driver.
946  * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will
947  * be informed that the file descriptor of a video device is available for
948  * reading.
949  * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor
950  * will be reported as available for writing.
951  *
952  * The return values from this function are intended to be directly returned
953  * from poll handler in driver.
954  */
955 __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file,
956 			   poll_table *wait);
957 
958 /**
959  * vb2_read() - implements read() syscall logic.
960  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
961  * @data:	pointed to target userspace buffer
962  * @count:	number of bytes to read
963  * @ppos:	file handle position tracking pointer
964  * @nonblock:	mode selector (1 means blocking calls, 0 means nonblocking)
965  */
966 size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count,
967 		loff_t *ppos, int nonblock);
968 /**
969  * vb2_read() - implements write() syscall logic.
970  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
971  * @data:	pointed to target userspace buffer
972  * @count:	number of bytes to write
973  * @ppos:	file handle position tracking pointer
974  * @nonblock:	mode selector (1 means blocking calls, 0 means nonblocking)
975  */
976 size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count,
977 		loff_t *ppos, int nonblock);
978 
979 /**
980  * typedef vb2_thread_fnc - callback function for use with vb2_thread.
981  *
982  * @vb: pointer to struct &vb2_buffer.
983  * @priv: pointer to a private data.
984  *
985  * This is called whenever a buffer is dequeued in the thread.
986  */
987 typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv);
988 
989 /**
990  * vb2_thread_start() - start a thread for the given queue.
991  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
992  * @fnc:	&vb2_thread_fnc callback function.
993  * @priv:	priv pointer passed to the callback function.
994  * @thread_name:the name of the thread. This will be prefixed with "vb2-".
995  *
996  * This starts a thread that will queue and dequeue until an error occurs
997  * or vb2_thread_stop() is called.
998  *
999  * .. attention::
1000  *
1001  *   This function should not be used for anything else but the videobuf2-dvb
1002  *   support. If you think you have another good use-case for this, then please
1003  *   contact the linux-media mailing list first.
1004  */
1005 int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv,
1006 		     const char *thread_name);
1007 
1008 /**
1009  * vb2_thread_stop() - stop the thread for the given queue.
1010  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1011  */
1012 int vb2_thread_stop(struct vb2_queue *q);
1013 
1014 /**
1015  * vb2_is_streaming() - return streaming status of the queue.
1016  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1017  */
vb2_is_streaming(struct vb2_queue * q)1018 static inline bool vb2_is_streaming(struct vb2_queue *q)
1019 {
1020 	return q->streaming;
1021 }
1022 
1023 /**
1024  * vb2_fileio_is_active() - return true if fileio is active.
1025  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1026  *
1027  * This returns true if read() or write() is used to stream the data
1028  * as opposed to stream I/O. This is almost never an important distinction,
1029  * except in rare cases. One such case is that using read() or write() to
1030  * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there
1031  * is no way you can pass the field information of each buffer to/from
1032  * userspace. A driver that supports this field format should check for
1033  * this in the &vb2_ops->queue_setup op and reject it if this function returns
1034  * true.
1035  */
vb2_fileio_is_active(struct vb2_queue * q)1036 static inline bool vb2_fileio_is_active(struct vb2_queue *q)
1037 {
1038 	return q->fileio;
1039 }
1040 
1041 /**
1042  * vb2_is_busy() - return busy status of the queue.
1043  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1044  *
1045  * This function checks if queue has any buffers allocated.
1046  */
vb2_is_busy(struct vb2_queue * q)1047 static inline bool vb2_is_busy(struct vb2_queue *q)
1048 {
1049 	return (q->num_buffers > 0);
1050 }
1051 
1052 /**
1053  * vb2_get_drv_priv() - return driver private data associated with the queue.
1054  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1055  */
vb2_get_drv_priv(struct vb2_queue * q)1056 static inline void *vb2_get_drv_priv(struct vb2_queue *q)
1057 {
1058 	return q->drv_priv;
1059 }
1060 
1061 /**
1062  * vb2_set_plane_payload() - set bytesused for the plane @plane_no.
1063  * @vb:		pointer to &struct vb2_buffer to which the plane in
1064  *		question belongs to.
1065  * @plane_no:	plane number for which payload should be set.
1066  * @size:	payload in bytes.
1067  */
vb2_set_plane_payload(struct vb2_buffer * vb,unsigned int plane_no,unsigned long size)1068 static inline void vb2_set_plane_payload(struct vb2_buffer *vb,
1069 				 unsigned int plane_no, unsigned long size)
1070 {
1071 	if (plane_no < vb->num_planes)
1072 		vb->planes[plane_no].bytesused = size;
1073 }
1074 
1075 /**
1076  * vb2_get_plane_payload() - get bytesused for the plane plane_no
1077  * @vb:		pointer to &struct vb2_buffer to which the plane in
1078  *		question belongs to.
1079  * @plane_no:	plane number for which payload should be set.
1080  */
vb2_get_plane_payload(struct vb2_buffer * vb,unsigned int plane_no)1081 static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb,
1082 				 unsigned int plane_no)
1083 {
1084 	if (plane_no < vb->num_planes)
1085 		return vb->planes[plane_no].bytesused;
1086 	return 0;
1087 }
1088 
1089 /**
1090  * vb2_plane_size() - return plane size in bytes.
1091  * @vb:		pointer to &struct vb2_buffer to which the plane in
1092  *		question belongs to.
1093  * @plane_no:	plane number for which size should be returned.
1094  */
1095 static inline unsigned long
vb2_plane_size(struct vb2_buffer * vb,unsigned int plane_no)1096 vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no)
1097 {
1098 	if (plane_no < vb->num_planes)
1099 		return vb->planes[plane_no].length;
1100 	return 0;
1101 }
1102 
1103 /**
1104  * vb2_start_streaming_called() - return streaming status of driver.
1105  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1106  */
vb2_start_streaming_called(struct vb2_queue * q)1107 static inline bool vb2_start_streaming_called(struct vb2_queue *q)
1108 {
1109 	return q->start_streaming_called;
1110 }
1111 
1112 /**
1113  * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue.
1114  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1115  */
vb2_clear_last_buffer_dequeued(struct vb2_queue * q)1116 static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q)
1117 {
1118 	q->last_buffer_dequeued = false;
1119 }
1120 
1121 /*
1122  * The following functions are not part of the vb2 core API, but are useful
1123  * functions for videobuf2-*.
1124  */
1125 
1126 /**
1127  * vb2_buffer_in_use() - return true if the buffer is in use and
1128  * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call.
1129  *
1130  * @vb:		buffer for which plane size should be returned.
1131  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1132  */
1133 bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb);
1134 
1135 /**
1136  * vb2_verify_memory_type() - Check whether the memory type and buffer type
1137  * passed to a buffer operation are compatible with the queue.
1138  *
1139  * @q:		pointer to &struct vb2_queue with videobuf2 queue.
1140  * @memory:	memory model, as defined by enum &vb2_memory.
1141  * @type:	private buffer type whose content is defined by the vb2-core
1142  *		caller. For example, for V4L2, it should match
1143  *		the types defined on enum &v4l2_buf_type.
1144  */
1145 int vb2_verify_memory_type(struct vb2_queue *q,
1146 		enum vb2_memory memory, unsigned int type);
1147 #endif /* _MEDIA_VIDEOBUF2_CORE_H */
1148