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 | #include <media/media-request.h> |
21 | #include <media/frame_vector.h> |
22 | |
23 | #define VB2_MAX_FRAME (32) |
24 | #define VB2_MAX_PLANES (8) |
25 | |
26 | /** |
27 | * enum vb2_memory - type of memory model used to make the buffers visible |
28 | * on userspace. |
29 | * |
30 | * @VB2_MEMORY_UNKNOWN: Buffer status is unknown or it is not used yet on |
31 | * userspace. |
32 | * @VB2_MEMORY_MMAP: The buffers are allocated by the Kernel and it is |
33 | * memory mapped via mmap() ioctl. This model is |
34 | * also used when the user is using the buffers via |
35 | * read() or write() system calls. |
36 | * @VB2_MEMORY_USERPTR: The buffers was allocated in userspace and it is |
37 | * memory mapped via mmap() ioctl. |
38 | * @VB2_MEMORY_DMABUF: The buffers are passed to userspace via DMA buffer. |
39 | */ |
40 | enum vb2_memory { |
41 | VB2_MEMORY_UNKNOWN = 0, |
42 | VB2_MEMORY_MMAP = 1, |
43 | VB2_MEMORY_USERPTR = 2, |
44 | VB2_MEMORY_DMABUF = 4, |
45 | }; |
46 | |
47 | struct vb2_fileio_data; |
48 | struct vb2_threadio_data; |
49 | struct vb2_buffer; |
50 | |
51 | /** |
52 | * struct vb2_mem_ops - memory handling/memory allocator operations. |
53 | * @alloc: allocate video memory and, optionally, allocator private data, |
54 | * return ERR_PTR() on failure or a pointer to allocator private, |
55 | * per-buffer data on success; the returned private structure |
56 | * will then be passed as @buf_priv argument to other ops in this |
57 | * structure. The size argument to this function shall be |
58 | * *page aligned*. |
59 | * @put: inform the allocator that the buffer will no longer be used; |
60 | * usually will result in the allocator freeing the buffer (if |
61 | * no other users of this buffer are present); the @buf_priv |
62 | * argument is the allocator private per-buffer structure |
63 | * previously returned from the alloc callback. |
64 | * @get_dmabuf: acquire userspace memory for a hardware operation; used for |
65 | * DMABUF memory types. |
66 | * @get_userptr: acquire userspace memory for a hardware operation; used for |
67 | * USERPTR memory types; vaddr is the address passed to the |
68 | * videobuf2 layer when queuing a video buffer of USERPTR type; |
69 | * should return an allocator private per-buffer structure |
70 | * associated with the buffer on success, ERR_PTR() on failure; |
71 | * the returned private structure will then be passed as @buf_priv |
72 | * argument to other ops in this structure. |
73 | * @put_userptr: inform the allocator that a USERPTR buffer will no longer |
74 | * be used. |
75 | * @attach_dmabuf: attach a shared &struct dma_buf for a hardware operation; |
76 | * used for DMABUF memory types; dev is the alloc device |
77 | * dbuf is the shared dma_buf; returns ERR_PTR() on failure; |
78 | * allocator private per-buffer structure on success; |
79 | * this needs to be used for further accesses to the buffer. |
80 | * @detach_dmabuf: inform the exporter of the buffer that the current DMABUF |
81 | * buffer is no longer used; the @buf_priv argument is the |
82 | * allocator private per-buffer structure previously returned |
83 | * from the attach_dmabuf callback. |
84 | * @map_dmabuf: request for access to the dmabuf from allocator; the allocator |
85 | * of dmabuf is informed that this driver is going to use the |
86 | * dmabuf. |
87 | * @unmap_dmabuf: releases access control to the dmabuf - allocator is notified |
88 | * that this driver is done using the dmabuf for now. |
89 | * @prepare: called every time the buffer is passed from userspace to the |
90 | * driver, useful for cache synchronisation, optional. |
91 | * @finish: called every time the buffer is passed back from the driver |
92 | * to the userspace, also optional. |
93 | * @vaddr: return a kernel virtual address to a given memory buffer |
94 | * associated with the passed private structure or NULL if no |
95 | * such mapping exists. |
96 | * @cookie: return allocator specific cookie for a given memory buffer |
97 | * associated with the passed private structure or NULL if not |
98 | * available. |
99 | * @num_users: return the current number of users of a memory buffer; |
100 | * return 1 if the videobuf2 layer (or actually the driver using |
101 | * it) is the only user. |
102 | * @mmap: setup a userspace mapping for a given memory buffer under |
103 | * the provided virtual memory region. |
104 | * |
105 | * Those operations are used by the videobuf2 core to implement the memory |
106 | * handling/memory allocators for each type of supported streaming I/O method. |
107 | * |
108 | * .. note:: |
109 | * #) Required ops for USERPTR types: get_userptr, put_userptr. |
110 | * |
111 | * #) Required ops for MMAP types: alloc, put, num_users, mmap. |
112 | * |
113 | * #) Required ops for read/write access types: alloc, put, num_users, vaddr. |
114 | * |
115 | * #) Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, |
116 | * map_dmabuf, unmap_dmabuf. |
117 | */ |
118 | struct vb2_mem_ops { |
119 | void *(*alloc)(struct vb2_buffer *vb, |
120 | struct device *dev, |
121 | unsigned long size); |
122 | void (*put)(void *buf_priv); |
123 | struct dma_buf *(*get_dmabuf)(struct vb2_buffer *vb, |
124 | void *buf_priv, |
125 | unsigned long flags); |
126 | |
127 | void *(*get_userptr)(struct vb2_buffer *vb, |
128 | struct device *dev, |
129 | unsigned long vaddr, |
130 | unsigned long size); |
131 | void (*put_userptr)(void *buf_priv); |
132 | |
133 | void (*prepare)(void *buf_priv); |
134 | void (*finish)(void *buf_priv); |
135 | |
136 | void *(*attach_dmabuf)(struct vb2_buffer *vb, |
137 | struct device *dev, |
138 | struct dma_buf *dbuf, |
139 | unsigned long size); |
140 | void (*detach_dmabuf)(void *buf_priv); |
141 | int (*map_dmabuf)(void *buf_priv); |
142 | void (*unmap_dmabuf)(void *buf_priv); |
143 | |
144 | void *(*vaddr)(struct vb2_buffer *vb, void *buf_priv); |
145 | void *(*cookie)(struct vb2_buffer *vb, void *buf_priv); |
146 | |
147 | unsigned int (*num_users)(void *buf_priv); |
148 | |
149 | int (*mmap)(void *buf_priv, struct vm_area_struct *vma); |
150 | }; |
151 | |
152 | /** |
153 | * struct vb2_plane - plane information. |
154 | * @mem_priv: private data with this plane. |
155 | * @dbuf: dma_buf - shared buffer object. |
156 | * @dbuf_mapped: flag to show whether dbuf is mapped or not |
157 | * @bytesused: number of bytes occupied by data in the plane (payload). |
158 | * @length: size of this plane (NOT the payload) in bytes. The maximum |
159 | * valid size is MAX_UINT - PAGE_SIZE. |
160 | * @min_length: minimum required size of this plane (NOT the payload) in bytes. |
161 | * @length is always greater or equal to @min_length, and like |
162 | * @length, it is limited to MAX_UINT - PAGE_SIZE. |
163 | * @m: Union with memtype-specific data. |
164 | * @m.offset: when memory in the associated struct vb2_buffer is |
165 | * %VB2_MEMORY_MMAP, equals the offset from the start of |
166 | * the device memory for this plane (or is a "cookie" that |
167 | * should be passed to mmap() called on the video node). |
168 | * @m.userptr: when memory is %VB2_MEMORY_USERPTR, a userspace pointer |
169 | * pointing to this plane. |
170 | * @m.fd: when memory is %VB2_MEMORY_DMABUF, a userspace file |
171 | * descriptor associated with this plane. |
172 | * @data_offset: offset in the plane to the start of data; usually 0, |
173 | * unless there is a header in front of the data. |
174 | * |
175 | * Should contain enough information to be able to cover all the fields |
176 | * of &struct v4l2_plane at videodev2.h. |
177 | */ |
178 | struct vb2_plane { |
179 | void *mem_priv; |
180 | struct dma_buf *dbuf; |
181 | unsigned int dbuf_mapped; |
182 | unsigned int bytesused; |
183 | unsigned int length; |
184 | unsigned int min_length; |
185 | union { |
186 | unsigned int offset; |
187 | unsigned long userptr; |
188 | int fd; |
189 | } m; |
190 | unsigned int data_offset; |
191 | }; |
192 | |
193 | /** |
194 | * enum vb2_io_modes - queue access methods. |
195 | * @VB2_MMAP: driver supports MMAP with streaming API. |
196 | * @VB2_USERPTR: driver supports USERPTR with streaming API. |
197 | * @VB2_READ: driver supports read() style access. |
198 | * @VB2_WRITE: driver supports write() style access. |
199 | * @VB2_DMABUF: driver supports DMABUF with streaming API. |
200 | */ |
201 | enum vb2_io_modes { |
202 | VB2_MMAP = BIT(0), |
203 | VB2_USERPTR = BIT(1), |
204 | VB2_READ = BIT(2), |
205 | VB2_WRITE = BIT(3), |
206 | VB2_DMABUF = BIT(4), |
207 | }; |
208 | |
209 | /** |
210 | * enum vb2_buffer_state - current video buffer state. |
211 | * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control. |
212 | * @VB2_BUF_STATE_IN_REQUEST: buffer is queued in media request. |
213 | * @VB2_BUF_STATE_PREPARING: buffer is being prepared in videobuf2. |
214 | * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf2, but not in driver. |
215 | * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used |
216 | * in a hardware operation. |
217 | * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf2, but |
218 | * not yet dequeued to userspace. |
219 | * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer |
220 | * has ended with an error, which will be reported |
221 | * to the userspace when it is dequeued. |
222 | */ |
223 | enum vb2_buffer_state { |
224 | VB2_BUF_STATE_DEQUEUED, |
225 | VB2_BUF_STATE_IN_REQUEST, |
226 | VB2_BUF_STATE_PREPARING, |
227 | VB2_BUF_STATE_QUEUED, |
228 | VB2_BUF_STATE_ACTIVE, |
229 | VB2_BUF_STATE_DONE, |
230 | VB2_BUF_STATE_ERROR, |
231 | }; |
232 | |
233 | struct vb2_queue; |
234 | |
235 | /** |
236 | * struct vb2_buffer - represents a video buffer. |
237 | * @vb2_queue: pointer to &struct vb2_queue with the queue to |
238 | * which this driver belongs. |
239 | * @index: id number of the buffer. |
240 | * @type: buffer type. |
241 | * @memory: the method, in which the actual data is passed. |
242 | * @num_planes: number of planes in the buffer |
243 | * on an internal driver queue. |
244 | * @timestamp: frame timestamp in ns. |
245 | * @request: the request this buffer is associated with. |
246 | * @req_obj: used to bind this buffer to a request. This |
247 | * request object has a refcount. |
248 | */ |
249 | struct vb2_buffer { |
250 | struct vb2_queue *vb2_queue; |
251 | unsigned int index; |
252 | unsigned int type; |
253 | unsigned int memory; |
254 | unsigned int num_planes; |
255 | u64 timestamp; |
256 | struct media_request *request; |
257 | struct media_request_object req_obj; |
258 | |
259 | /* private: internal use only |
260 | * |
261 | * state: current buffer state; do not change |
262 | * synced: this buffer has been synced for DMA, i.e. the |
263 | * 'prepare' memop was called. It is cleared again |
264 | * after the 'finish' memop is called. |
265 | * prepared: this buffer has been prepared, i.e. the |
266 | * buf_prepare op was called. It is cleared again |
267 | * after the 'buf_finish' op is called. |
268 | * copied_timestamp: the timestamp of this capture buffer was copied |
269 | * from an output buffer. |
270 | * skip_cache_sync_on_prepare: when set buffer's ->prepare() function |
271 | * skips cache sync/invalidation. |
272 | * skip_cache_sync_on_finish: when set buffer's ->finish() function |
273 | * skips cache sync/invalidation. |
274 | * queued_entry: entry on the queued buffers list, which holds |
275 | * all buffers queued from userspace |
276 | * done_entry: entry on the list that stores all buffers ready |
277 | * to be dequeued to userspace |
278 | * vb2_plane: per-plane information; do not change |
279 | */ |
280 | enum vb2_buffer_state state; |
281 | unsigned int synced:1; |
282 | unsigned int prepared:1; |
283 | unsigned int copied_timestamp:1; |
284 | unsigned int skip_cache_sync_on_prepare:1; |
285 | unsigned int skip_cache_sync_on_finish:1; |
286 | |
287 | struct vb2_plane planes[VB2_MAX_PLANES]; |
288 | struct list_head queued_entry; |
289 | struct list_head done_entry; |
290 | #ifdef CONFIG_VIDEO_ADV_DEBUG |
291 | /* |
292 | * Counters for how often these buffer-related ops are |
293 | * called. Used to check for unbalanced ops. |
294 | */ |
295 | u32 cnt_mem_alloc; |
296 | u32 cnt_mem_put; |
297 | u32 cnt_mem_get_dmabuf; |
298 | u32 cnt_mem_get_userptr; |
299 | u32 cnt_mem_put_userptr; |
300 | u32 cnt_mem_prepare; |
301 | u32 cnt_mem_finish; |
302 | u32 cnt_mem_attach_dmabuf; |
303 | u32 cnt_mem_detach_dmabuf; |
304 | u32 cnt_mem_map_dmabuf; |
305 | u32 cnt_mem_unmap_dmabuf; |
306 | u32 cnt_mem_vaddr; |
307 | u32 cnt_mem_cookie; |
308 | u32 cnt_mem_num_users; |
309 | u32 cnt_mem_mmap; |
310 | |
311 | u32 cnt_buf_out_validate; |
312 | u32 cnt_buf_init; |
313 | u32 cnt_buf_prepare; |
314 | u32 cnt_buf_finish; |
315 | u32 cnt_buf_cleanup; |
316 | u32 cnt_buf_queue; |
317 | u32 cnt_buf_request_complete; |
318 | |
319 | /* This counts the number of calls to vb2_buffer_done() */ |
320 | u32 cnt_buf_done; |
321 | #endif |
322 | }; |
323 | |
324 | /** |
325 | * struct vb2_ops - driver-specific callbacks. |
326 | * |
327 | * These operations are not called from interrupt context except where |
328 | * mentioned specifically. |
329 | * |
330 | * @queue_setup: called from VIDIOC_REQBUFS() and VIDIOC_CREATE_BUFS() |
331 | * handlers before memory allocation. It can be called |
332 | * twice: if the original number of requested buffers |
333 | * could not be allocated, then it will be called a |
334 | * second time with the actually allocated number of |
335 | * buffers to verify if that is OK. |
336 | * The driver should return the required number of buffers |
337 | * in \*num_buffers, the required number of planes per |
338 | * buffer in \*num_planes, the size of each plane should be |
339 | * set in the sizes\[\] array and optional per-plane |
340 | * allocator specific device in the alloc_devs\[\] array. |
341 | * When called from VIDIOC_REQBUFS(), \*num_planes == 0, |
342 | * the driver has to use the currently configured format to |
343 | * determine the plane sizes and \*num_buffers is the total |
344 | * number of buffers that are being allocated. When called |
345 | * from VIDIOC_CREATE_BUFS(), \*num_planes != 0 and it |
346 | * describes the requested number of planes and sizes\[\] |
347 | * contains the requested plane sizes. In this case |
348 | * \*num_buffers are being allocated additionally to |
349 | * q->num_buffers. If either \*num_planes or the requested |
350 | * sizes are invalid callback must return %-EINVAL. |
351 | * @wait_prepare: release any locks taken while calling vb2 functions; |
352 | * it is called before an ioctl needs to wait for a new |
353 | * buffer to arrive; required to avoid a deadlock in |
354 | * blocking access type. |
355 | * @wait_finish: reacquire all locks released in the previous callback; |
356 | * required to continue operation after sleeping while |
357 | * waiting for a new buffer to arrive. |
358 | * @buf_out_validate: called when the output buffer is prepared or queued |
359 | * to a request; drivers can use this to validate |
360 | * userspace-provided information; this is required only |
361 | * for OUTPUT queues. |
362 | * @buf_init: called once after allocating a buffer (in MMAP case) |
363 | * or after acquiring a new USERPTR buffer; drivers may |
364 | * perform additional buffer-related initialization; |
365 | * initialization failure (return != 0) will prevent |
366 | * queue setup from completing successfully; optional. |
367 | * @buf_prepare: called every time the buffer is queued from userspace |
368 | * and from the VIDIOC_PREPARE_BUF() ioctl; drivers may |
369 | * perform any initialization required before each |
370 | * hardware operation in this callback; drivers can |
371 | * access/modify the buffer here as it is still synced for |
372 | * the CPU; drivers that support VIDIOC_CREATE_BUFS() must |
373 | * also validate the buffer size; if an error is returned, |
374 | * the buffer will not be queued in driver; optional. |
375 | * @buf_finish: called before every dequeue of the buffer back to |
376 | * userspace; the buffer is synced for the CPU, so drivers |
377 | * can access/modify the buffer contents; drivers may |
378 | * perform any operations required before userspace |
379 | * accesses the buffer; optional. The buffer state can be |
380 | * one of the following: %DONE and %ERROR occur while |
381 | * streaming is in progress, and the %PREPARED state occurs |
382 | * when the queue has been canceled and all pending |
383 | * buffers are being returned to their default %DEQUEUED |
384 | * state. Typically you only have to do something if the |
385 | * state is %VB2_BUF_STATE_DONE, since in all other cases |
386 | * the buffer contents will be ignored anyway. |
387 | * @buf_cleanup: called once before the buffer is freed; drivers may |
388 | * perform any additional cleanup; optional. |
389 | * @prepare_streaming: called once to prepare for 'streaming' state; this is |
390 | * where validation can be done to verify everything is |
391 | * okay and streaming resources can be claimed. It is |
392 | * called when the VIDIOC_STREAMON ioctl is called. The |
393 | * actual streaming starts when @start_streaming is called. |
394 | * Optional. |
395 | * @start_streaming: called once to enter 'streaming' state; the driver may |
396 | * receive buffers with @buf_queue callback |
397 | * before @start_streaming is called; the driver gets the |
398 | * number of already queued buffers in count parameter; |
399 | * driver can return an error if hardware fails, in that |
400 | * case all buffers that have been already given by |
401 | * the @buf_queue callback are to be returned by the driver |
402 | * by calling vb2_buffer_done() with %VB2_BUF_STATE_QUEUED. |
403 | * If you need a minimum number of buffers before you can |
404 | * start streaming, then set |
405 | * &vb2_queue->min_buffers_needed. If that is non-zero |
406 | * then @start_streaming won't be called until at least |
407 | * that many buffers have been queued up by userspace. |
408 | * @stop_streaming: called when 'streaming' state must be disabled; driver |
409 | * should stop any DMA transactions or wait until they |
410 | * finish and give back all buffers it got from &buf_queue |
411 | * callback by calling vb2_buffer_done() with either |
412 | * %VB2_BUF_STATE_DONE or %VB2_BUF_STATE_ERROR; may use |
413 | * vb2_wait_for_all_buffers() function |
414 | * @unprepare_streaming:called as counterpart to @prepare_streaming; any claimed |
415 | * streaming resources can be released here. It is |
416 | * called when the VIDIOC_STREAMOFF ioctls is called or |
417 | * when the streaming filehandle is closed. Optional. |
418 | * @buf_queue: passes buffer vb to the driver; driver may start |
419 | * hardware operation on this buffer; driver should give |
420 | * the buffer back by calling vb2_buffer_done() function; |
421 | * it is always called after calling VIDIOC_STREAMON() |
422 | * ioctl; might be called before @start_streaming callback |
423 | * if user pre-queued buffers before calling |
424 | * VIDIOC_STREAMON(). |
425 | * @buf_request_complete: a buffer that was never queued to the driver but is |
426 | * associated with a queued request was canceled. |
427 | * The driver will have to mark associated objects in the |
428 | * request as completed; required if requests are |
429 | * supported. |
430 | */ |
431 | struct vb2_ops { |
432 | int (*queue_setup)(struct vb2_queue *q, |
433 | unsigned int *num_buffers, unsigned int *num_planes, |
434 | unsigned int sizes[], struct device *alloc_devs[]); |
435 | |
436 | void (*wait_prepare)(struct vb2_queue *q); |
437 | void (*wait_finish)(struct vb2_queue *q); |
438 | |
439 | int (*buf_out_validate)(struct vb2_buffer *vb); |
440 | int (*buf_init)(struct vb2_buffer *vb); |
441 | int (*buf_prepare)(struct vb2_buffer *vb); |
442 | void (*buf_finish)(struct vb2_buffer *vb); |
443 | void (*buf_cleanup)(struct vb2_buffer *vb); |
444 | |
445 | int (*prepare_streaming)(struct vb2_queue *q); |
446 | int (*start_streaming)(struct vb2_queue *q, unsigned int count); |
447 | void (*stop_streaming)(struct vb2_queue *q); |
448 | void (*unprepare_streaming)(struct vb2_queue *q); |
449 | |
450 | void (*buf_queue)(struct vb2_buffer *vb); |
451 | |
452 | void (*buf_request_complete)(struct vb2_buffer *vb); |
453 | }; |
454 | |
455 | /** |
456 | * struct vb2_buf_ops - driver-specific callbacks. |
457 | * |
458 | * @verify_planes_array: Verify that a given user space structure contains |
459 | * enough planes for the buffer. This is called |
460 | * for each dequeued buffer. |
461 | * @init_buffer: given a &vb2_buffer initialize the extra data after |
462 | * struct vb2_buffer. |
463 | * For V4L2 this is a &struct vb2_v4l2_buffer. |
464 | * @fill_user_buffer: given a &vb2_buffer fill in the userspace structure. |
465 | * For V4L2 this is a &struct v4l2_buffer. |
466 | * @fill_vb2_buffer: given a userspace structure, fill in the &vb2_buffer. |
467 | * If the userspace structure is invalid, then this op |
468 | * will return an error. |
469 | * @copy_timestamp: copy the timestamp from a userspace structure to |
470 | * the &struct vb2_buffer. |
471 | */ |
472 | struct vb2_buf_ops { |
473 | int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb); |
474 | void (*init_buffer)(struct vb2_buffer *vb); |
475 | void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb); |
476 | int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes); |
477 | void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb); |
478 | }; |
479 | |
480 | /** |
481 | * struct vb2_queue - a videobuf2 queue. |
482 | * |
483 | * @type: private buffer type whose content is defined by the vb2-core |
484 | * caller. For example, for V4L2, it should match |
485 | * the types defined on &enum v4l2_buf_type. |
486 | * @io_modes: supported io methods (see &enum vb2_io_modes). |
487 | * @alloc_devs: &struct device memory type/allocator-specific per-plane device |
488 | * @dev: device to use for the default allocation context if the driver |
489 | * doesn't fill in the @alloc_devs array. |
490 | * @dma_attrs: DMA attributes to use for the DMA. |
491 | * @bidirectional: when this flag is set the DMA direction for the buffers of |
492 | * this queue will be overridden with %DMA_BIDIRECTIONAL direction. |
493 | * This is useful in cases where the hardware (firmware) writes to |
494 | * a buffer which is mapped as read (%DMA_TO_DEVICE), or reads from |
495 | * buffer which is mapped for write (%DMA_FROM_DEVICE) in order |
496 | * to satisfy some internal hardware restrictions or adds a padding |
497 | * needed by the processing algorithm. In case the DMA mapping is |
498 | * not bidirectional but the hardware (firmware) trying to access |
499 | * the buffer (in the opposite direction) this could lead to an |
500 | * IOMMU protection faults. |
501 | * @fileio_read_once: report EOF after reading the first buffer |
502 | * @fileio_write_immediately: queue buffer after each write() call |
503 | * @allow_zero_bytesused: allow bytesused == 0 to be passed to the driver |
504 | * @quirk_poll_must_check_waiting_for_buffers: Return %EPOLLERR at poll when QBUF |
505 | * has not been called. This is a vb1 idiom that has been adopted |
506 | * also by vb2. |
507 | * @supports_requests: this queue supports the Request API. |
508 | * @requires_requests: this queue requires the Request API. If this is set to 1, |
509 | * then supports_requests must be set to 1 as well. |
510 | * @uses_qbuf: qbuf was used directly for this queue. Set to 1 the first |
511 | * time this is called. Set to 0 when the queue is canceled. |
512 | * If this is 1, then you cannot queue buffers from a request. |
513 | * @uses_requests: requests are used for this queue. Set to 1 the first time |
514 | * a request is queued. Set to 0 when the queue is canceled. |
515 | * If this is 1, then you cannot queue buffers directly. |
516 | * @allow_cache_hints: when set user-space can pass cache management hints in |
517 | * order to skip cache flush/invalidation on ->prepare() or/and |
518 | * ->finish(). |
519 | * @non_coherent_mem: when set queue will attempt to allocate buffers using |
520 | * non-coherent memory. |
521 | * @lock: pointer to a mutex that protects the &struct vb2_queue. The |
522 | * driver can set this to a mutex to let the v4l2 core serialize |
523 | * the queuing ioctls. If the driver wants to handle locking |
524 | * itself, then this should be set to NULL. This lock is not used |
525 | * by the videobuf2 core API. |
526 | * @owner: The filehandle that 'owns' the buffers, i.e. the filehandle |
527 | * that called reqbufs, create_buffers or started fileio. |
528 | * This field is not used by the videobuf2 core API, but it allows |
529 | * drivers to easily associate an owner filehandle with the queue. |
530 | * @ops: driver-specific callbacks |
531 | * @mem_ops: memory allocator specific callbacks |
532 | * @buf_ops: callbacks to deliver buffer information. |
533 | * between user-space and kernel-space. |
534 | * @drv_priv: driver private data. |
535 | * @subsystem_flags: Flags specific to the subsystem (V4L2/DVB/etc.). Not used |
536 | * by the vb2 core. |
537 | * @buf_struct_size: size of the driver-specific buffer structure; |
538 | * "0" indicates the driver doesn't want to use a custom buffer |
539 | * structure type. In that case a subsystem-specific struct |
540 | * will be used (in the case of V4L2 that is |
541 | * ``sizeof(struct vb2_v4l2_buffer)``). The first field of the |
542 | * driver-specific buffer structure must be the subsystem-specific |
543 | * struct (vb2_v4l2_buffer in the case of V4L2). |
544 | * @timestamp_flags: Timestamp flags; ``V4L2_BUF_FLAG_TIMESTAMP_*`` and |
545 | * ``V4L2_BUF_FLAG_TSTAMP_SRC_*`` |
546 | * @gfp_flags: additional gfp flags used when allocating the buffers. |
547 | * Typically this is 0, but it may be e.g. %GFP_DMA or %__GFP_DMA32 |
548 | * to force the buffer allocation to a specific memory zone. |
549 | * @min_buffers_needed: the minimum number of buffers needed before |
550 | * @start_streaming can be called. Used when a DMA engine |
551 | * cannot be started unless at least this number of buffers |
552 | * have been queued into the driver. |
553 | */ |
554 | /* |
555 | * Private elements (won't appear at the uAPI book): |
556 | * @mmap_lock: private mutex used when buffers are allocated/freed/mmapped |
557 | * @memory: current memory type used |
558 | * @dma_dir: DMA mapping direction. |
559 | * @bufs: videobuf2 buffer structures |
560 | * @num_buffers: number of allocated/used buffers |
561 | * @queued_list: list of buffers currently queued from userspace |
562 | * @queued_count: number of buffers queued and ready for streaming. |
563 | * @owned_by_drv_count: number of buffers owned by the driver |
564 | * @done_list: list of buffers ready to be dequeued to userspace |
565 | * @done_lock: lock to protect done_list list |
566 | * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued |
567 | * @streaming: current streaming state |
568 | * @start_streaming_called: @start_streaming was called successfully and we |
569 | * started streaming. |
570 | * @error: a fatal error occurred on the queue |
571 | * @waiting_for_buffers: used in poll() to check if vb2 is still waiting for |
572 | * buffers. Only set for capture queues if qbuf has not yet been |
573 | * called since poll() needs to return %EPOLLERR in that situation. |
574 | * @is_multiplanar: set if buffer type is multiplanar |
575 | * @is_output: set if buffer type is output |
576 | * @copy_timestamp: set if vb2-core should set timestamps |
577 | * @last_buffer_dequeued: used in poll() and DQBUF to immediately return if the |
578 | * last decoded buffer was already dequeued. Set for capture queues |
579 | * when a buffer with the %V4L2_BUF_FLAG_LAST is dequeued. |
580 | * @fileio: file io emulator internal data, used only if emulator is active |
581 | * @threadio: thread io internal data, used only if thread is active |
582 | * @name: queue name, used for logging purpose. Initialized automatically |
583 | * if left empty by drivers. |
584 | */ |
585 | struct vb2_queue { |
586 | unsigned int type; |
587 | unsigned int io_modes; |
588 | struct device *dev; |
589 | unsigned long dma_attrs; |
590 | unsigned int bidirectional:1; |
591 | unsigned int fileio_read_once:1; |
592 | unsigned int fileio_write_immediately:1; |
593 | unsigned int allow_zero_bytesused:1; |
594 | unsigned int quirk_poll_must_check_waiting_for_buffers:1; |
595 | unsigned int supports_requests:1; |
596 | unsigned int requires_requests:1; |
597 | unsigned int uses_qbuf:1; |
598 | unsigned int uses_requests:1; |
599 | unsigned int allow_cache_hints:1; |
600 | unsigned int non_coherent_mem:1; |
601 | |
602 | struct mutex *lock; |
603 | void *owner; |
604 | |
605 | const struct vb2_ops *ops; |
606 | const struct vb2_mem_ops *mem_ops; |
607 | const struct vb2_buf_ops *buf_ops; |
608 | |
609 | void *drv_priv; |
610 | u32 subsystem_flags; |
611 | unsigned int buf_struct_size; |
612 | u32 timestamp_flags; |
613 | gfp_t gfp_flags; |
614 | u32 min_buffers_needed; |
615 | |
616 | struct device *alloc_devs[VB2_MAX_PLANES]; |
617 | |
618 | /* private: internal use only */ |
619 | struct mutex mmap_lock; |
620 | unsigned int memory; |
621 | enum dma_data_direction dma_dir; |
622 | struct vb2_buffer *bufs[VB2_MAX_FRAME]; |
623 | unsigned int num_buffers; |
624 | |
625 | struct list_head queued_list; |
626 | unsigned int queued_count; |
627 | |
628 | atomic_t owned_by_drv_count; |
629 | struct list_head done_list; |
630 | spinlock_t done_lock; |
631 | wait_queue_head_t done_wq; |
632 | |
633 | unsigned int streaming:1; |
634 | unsigned int start_streaming_called:1; |
635 | unsigned int error:1; |
636 | unsigned int waiting_for_buffers:1; |
637 | unsigned int waiting_in_dqbuf:1; |
638 | unsigned int is_multiplanar:1; |
639 | unsigned int is_output:1; |
640 | unsigned int copy_timestamp:1; |
641 | unsigned int last_buffer_dequeued:1; |
642 | |
643 | struct vb2_fileio_data *fileio; |
644 | struct vb2_threadio_data *threadio; |
645 | |
646 | char name[32]; |
647 | |
648 | #ifdef CONFIG_VIDEO_ADV_DEBUG |
649 | /* |
650 | * Counters for how often these queue-related ops are |
651 | * called. Used to check for unbalanced ops. |
652 | */ |
653 | u32 cnt_queue_setup; |
654 | u32 cnt_wait_prepare; |
655 | u32 cnt_wait_finish; |
656 | u32 cnt_prepare_streaming; |
657 | u32 cnt_start_streaming; |
658 | u32 cnt_stop_streaming; |
659 | u32 cnt_unprepare_streaming; |
660 | #endif |
661 | }; |
662 | |
663 | /** |
664 | * vb2_queue_allows_cache_hints() - Return true if the queue allows cache |
665 | * and memory consistency hints. |
666 | * |
667 | * @q: pointer to &struct vb2_queue with videobuf2 queue |
668 | */ |
669 | static inline bool vb2_queue_allows_cache_hints(struct vb2_queue *q) |
670 | { |
671 | return q->allow_cache_hints && q->memory == VB2_MEMORY_MMAP; |
672 | } |
673 | |
674 | /** |
675 | * vb2_plane_vaddr() - Return a kernel virtual address of a given plane. |
676 | * @vb: pointer to &struct vb2_buffer to which the plane in |
677 | * question belongs to. |
678 | * @plane_no: plane number for which the address is to be returned. |
679 | * |
680 | * This function returns a kernel virtual address of a given plane if |
681 | * such a mapping exist, NULL otherwise. |
682 | */ |
683 | void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); |
684 | |
685 | /** |
686 | * vb2_plane_cookie() - Return allocator specific cookie for the given plane. |
687 | * @vb: pointer to &struct vb2_buffer to which the plane in |
688 | * question belongs to. |
689 | * @plane_no: plane number for which the cookie is to be returned. |
690 | * |
691 | * This function returns an allocator specific cookie for a given plane if |
692 | * available, NULL otherwise. The allocator should provide some simple static |
693 | * inline function, which would convert this cookie to the allocator specific |
694 | * type that can be used directly by the driver to access the buffer. This can |
695 | * be for example physical address, pointer to scatter list or IOMMU mapping. |
696 | */ |
697 | void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); |
698 | |
699 | /** |
700 | * vb2_buffer_done() - inform videobuf2 that an operation on a buffer |
701 | * is finished. |
702 | * @vb: pointer to &struct vb2_buffer to be used. |
703 | * @state: state of the buffer, as defined by &enum vb2_buffer_state. |
704 | * Either %VB2_BUF_STATE_DONE if the operation finished |
705 | * successfully, %VB2_BUF_STATE_ERROR if the operation finished |
706 | * with an error or %VB2_BUF_STATE_QUEUED. |
707 | * |
708 | * This function should be called by the driver after a hardware operation on |
709 | * a buffer is finished and the buffer may be returned to userspace. The driver |
710 | * cannot use this buffer anymore until it is queued back to it by videobuf |
711 | * by the means of &vb2_ops->buf_queue callback. Only buffers previously queued |
712 | * to the driver by &vb2_ops->buf_queue can be passed to this function. |
713 | * |
714 | * While streaming a buffer can only be returned in state DONE or ERROR. |
715 | * The &vb2_ops->start_streaming op can also return them in case the DMA engine |
716 | * cannot be started for some reason. In that case the buffers should be |
717 | * returned with state QUEUED to put them back into the queue. |
718 | */ |
719 | void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); |
720 | |
721 | /** |
722 | * vb2_discard_done() - discard all buffers marked as DONE. |
723 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
724 | * |
725 | * This function is intended to be used with suspend/resume operations. It |
726 | * discards all 'done' buffers as they would be too old to be requested after |
727 | * resume. |
728 | * |
729 | * Drivers must stop the hardware and synchronize with interrupt handlers and/or |
730 | * delayed works before calling this function to make sure no buffer will be |
731 | * touched by the driver and/or hardware. |
732 | */ |
733 | void vb2_discard_done(struct vb2_queue *q); |
734 | |
735 | /** |
736 | * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2. |
737 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
738 | * |
739 | * This function will wait until all buffers that have been given to the driver |
740 | * by &vb2_ops->buf_queue are given back to vb2 with vb2_buffer_done(). It |
741 | * doesn't call &vb2_ops->wait_prepare/&vb2_ops->wait_finish pair. |
742 | * It is intended to be called with all locks taken, for example from |
743 | * &vb2_ops->stop_streaming callback. |
744 | */ |
745 | int vb2_wait_for_all_buffers(struct vb2_queue *q); |
746 | |
747 | /** |
748 | * vb2_core_querybuf() - query video buffer information. |
749 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
750 | * @index: id number of the buffer. |
751 | * @pb: buffer struct passed from userspace. |
752 | * |
753 | * Videobuf2 core helper to implement VIDIOC_QUERYBUF() operation. It is called |
754 | * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
755 | * |
756 | * The passed buffer should have been verified. |
757 | * |
758 | * This function fills the relevant information for the userspace. |
759 | * |
760 | * Return: returns zero on success; an error code otherwise. |
761 | */ |
762 | void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb); |
763 | |
764 | /** |
765 | * vb2_core_reqbufs() - Initiate streaming. |
766 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
767 | * @memory: memory type, as defined by &enum vb2_memory. |
768 | * @flags: auxiliary queue/buffer management flags. Currently, the only |
769 | * used flag is %V4L2_MEMORY_FLAG_NON_COHERENT. |
770 | * @count: requested buffer count. |
771 | * |
772 | * Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called |
773 | * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
774 | * |
775 | * This function: |
776 | * |
777 | * #) verifies streaming parameters passed from the userspace; |
778 | * #) sets up the queue; |
779 | * #) negotiates number of buffers and planes per buffer with the driver |
780 | * to be used during streaming; |
781 | * #) allocates internal buffer structures (&struct vb2_buffer), according to |
782 | * the agreed parameters; |
783 | * #) for MMAP memory type, allocates actual video memory, using the |
784 | * memory handling/allocation routines provided during queue initialization. |
785 | * |
786 | * If req->count is 0, all the memory will be freed instead. |
787 | * |
788 | * If the queue has been allocated previously by a previous vb2_core_reqbufs() |
789 | * call and the queue is not busy, memory will be reallocated. |
790 | * |
791 | * Return: returns zero on success; an error code otherwise. |
792 | */ |
793 | int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, |
794 | unsigned int flags, unsigned int *count); |
795 | |
796 | /** |
797 | * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs |
798 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
799 | * @memory: memory type, as defined by &enum vb2_memory. |
800 | * @flags: auxiliary queue/buffer management flags. |
801 | * @count: requested buffer count. |
802 | * @requested_planes: number of planes requested. |
803 | * @requested_sizes: array with the size of the planes. |
804 | * |
805 | * Videobuf2 core helper to implement VIDIOC_CREATE_BUFS() operation. It is |
806 | * called internally by VB2 by an API-specific handler, like |
807 | * ``videobuf2-v4l2.h``. |
808 | * |
809 | * This function: |
810 | * |
811 | * #) verifies parameter sanity; |
812 | * #) calls the &vb2_ops->queue_setup queue operation; |
813 | * #) performs any necessary memory allocations. |
814 | * |
815 | * Return: returns zero on success; an error code otherwise. |
816 | */ |
817 | int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, |
818 | unsigned int flags, unsigned int *count, |
819 | unsigned int requested_planes, |
820 | const unsigned int requested_sizes[]); |
821 | |
822 | /** |
823 | * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace |
824 | * to the kernel. |
825 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
826 | * @index: id number of the buffer. |
827 | * @pb: buffer structure passed from userspace to |
828 | * &v4l2_ioctl_ops->vidioc_prepare_buf handler in driver. |
829 | * |
830 | * Videobuf2 core helper to implement VIDIOC_PREPARE_BUF() operation. It is |
831 | * called internally by VB2 by an API-specific handler, like |
832 | * ``videobuf2-v4l2.h``. |
833 | * |
834 | * The passed buffer should have been verified. |
835 | * |
836 | * This function calls vb2_ops->buf_prepare callback in the driver |
837 | * (if provided), in which driver-specific buffer initialization can |
838 | * be performed. |
839 | * |
840 | * Return: returns zero on success; an error code otherwise. |
841 | */ |
842 | int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); |
843 | |
844 | /** |
845 | * vb2_core_qbuf() - Queue a buffer from userspace |
846 | * |
847 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
848 | * @index: id number of the buffer |
849 | * @pb: buffer structure passed from userspace to |
850 | * v4l2_ioctl_ops->vidioc_qbuf handler in driver |
851 | * @req: pointer to &struct media_request, may be NULL. |
852 | * |
853 | * Videobuf2 core helper to implement VIDIOC_QBUF() operation. It is called |
854 | * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
855 | * |
856 | * This function: |
857 | * |
858 | * #) If @req is non-NULL, then the buffer will be bound to this |
859 | * media request and it returns. The buffer will be prepared and |
860 | * queued to the driver (i.e. the next two steps) when the request |
861 | * itself is queued. |
862 | * #) if necessary, calls &vb2_ops->buf_prepare callback in the driver |
863 | * (if provided), in which driver-specific buffer initialization can |
864 | * be performed; |
865 | * #) if streaming is on, queues the buffer in driver by the means of |
866 | * &vb2_ops->buf_queue callback for processing. |
867 | * |
868 | * Return: returns zero on success; an error code otherwise. |
869 | */ |
870 | int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb, |
871 | struct media_request *req); |
872 | |
873 | /** |
874 | * vb2_core_dqbuf() - Dequeue a buffer to the userspace |
875 | * @q: pointer to &struct vb2_queue with videobuf2 queue |
876 | * @pindex: pointer to the buffer index. May be NULL |
877 | * @pb: buffer structure passed from userspace to |
878 | * v4l2_ioctl_ops->vidioc_dqbuf handler in driver. |
879 | * @nonblocking: if true, this call will not sleep waiting for a buffer if no |
880 | * buffers ready for dequeuing are present. Normally the driver |
881 | * would be passing (file->f_flags & O_NONBLOCK) here. |
882 | * |
883 | * Videobuf2 core helper to implement VIDIOC_DQBUF() operation. It is called |
884 | * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
885 | * |
886 | * This function: |
887 | * |
888 | * #) calls buf_finish callback in the driver (if provided), in which |
889 | * driver can perform any additional operations that may be required before |
890 | * returning the buffer to userspace, such as cache sync, |
891 | * #) the buffer struct members are filled with relevant information for |
892 | * the userspace. |
893 | * |
894 | * Return: returns zero on success; an error code otherwise. |
895 | */ |
896 | int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, |
897 | bool nonblocking); |
898 | |
899 | /** |
900 | * vb2_core_streamon() - Implements VB2 stream ON logic |
901 | * |
902 | * @q: pointer to &struct vb2_queue with videobuf2 queue |
903 | * @type: type of the queue to be started. |
904 | * For V4L2, this is defined by &enum v4l2_buf_type type. |
905 | * |
906 | * Videobuf2 core helper to implement VIDIOC_STREAMON() operation. It is called |
907 | * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
908 | * |
909 | * Return: returns zero on success; an error code otherwise. |
910 | */ |
911 | int vb2_core_streamon(struct vb2_queue *q, unsigned int type); |
912 | |
913 | /** |
914 | * vb2_core_streamoff() - Implements VB2 stream OFF logic |
915 | * |
916 | * @q: pointer to &struct vb2_queue with videobuf2 queue |
917 | * @type: type of the queue to be started. |
918 | * For V4L2, this is defined by &enum v4l2_buf_type type. |
919 | * |
920 | * Videobuf2 core helper to implement VIDIOC_STREAMOFF() operation. It is |
921 | * called internally by VB2 by an API-specific handler, like |
922 | * ``videobuf2-v4l2.h``. |
923 | * |
924 | * Return: returns zero on success; an error code otherwise. |
925 | */ |
926 | int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); |
927 | |
928 | /** |
929 | * vb2_core_expbuf() - Export a buffer as a file descriptor. |
930 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
931 | * @fd: pointer to the file descriptor associated with DMABUF |
932 | * (set by driver). |
933 | * @type: buffer type. |
934 | * @index: id number of the buffer. |
935 | * @plane: index of the plane to be exported, 0 for single plane queues |
936 | * @flags: file flags for newly created file, as defined at |
937 | * include/uapi/asm-generic/fcntl.h. |
938 | * Currently, the only used flag is %O_CLOEXEC. |
939 | * is supported, refer to manual of open syscall for more details. |
940 | * |
941 | * |
942 | * Videobuf2 core helper to implement VIDIOC_EXPBUF() operation. It is called |
943 | * internally by VB2 by an API-specific handler, like ``videobuf2-v4l2.h``. |
944 | * |
945 | * Return: returns zero on success; an error code otherwise. |
946 | */ |
947 | int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, |
948 | unsigned int index, unsigned int plane, unsigned int flags); |
949 | |
950 | /** |
951 | * vb2_core_queue_init() - initialize a videobuf2 queue |
952 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
953 | * This structure should be allocated in driver |
954 | * |
955 | * The &vb2_queue structure should be allocated by the driver. The driver is |
956 | * responsible of clearing it's content and setting initial values for some |
957 | * required entries before calling this function. |
958 | * |
959 | * .. note:: |
960 | * |
961 | * The following fields at @q should be set before calling this function: |
962 | * &vb2_queue->ops, &vb2_queue->mem_ops, &vb2_queue->type. |
963 | */ |
964 | int vb2_core_queue_init(struct vb2_queue *q); |
965 | |
966 | /** |
967 | * vb2_core_queue_release() - stop streaming, release the queue and free memory |
968 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
969 | * |
970 | * This function stops streaming and performs necessary clean ups, including |
971 | * freeing video buffer memory. The driver is responsible for freeing |
972 | * the &struct vb2_queue itself. |
973 | */ |
974 | void vb2_core_queue_release(struct vb2_queue *q); |
975 | |
976 | /** |
977 | * vb2_queue_error() - signal a fatal error on the queue |
978 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
979 | * |
980 | * Flag that a fatal unrecoverable error has occurred and wake up all processes |
981 | * waiting on the queue. Polling will now set %EPOLLERR and queuing and dequeuing |
982 | * buffers will return %-EIO. |
983 | * |
984 | * The error flag will be cleared when canceling the queue, either from |
985 | * vb2_streamoff() or vb2_queue_release(). Drivers should thus not call this |
986 | * function before starting the stream, otherwise the error flag will remain set |
987 | * until the queue is released when closing the device node. |
988 | */ |
989 | void vb2_queue_error(struct vb2_queue *q); |
990 | |
991 | /** |
992 | * vb2_mmap() - map video buffers into application address space. |
993 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
994 | * @vma: pointer to &struct vm_area_struct with the vma passed |
995 | * to the mmap file operation handler in the driver. |
996 | * |
997 | * Should be called from mmap file operation handler of a driver. |
998 | * This function maps one plane of one of the available video buffers to |
999 | * userspace. To map whole video memory allocated on reqbufs, this function |
1000 | * has to be called once per each plane per each buffer previously allocated. |
1001 | * |
1002 | * When the userspace application calls mmap, it passes to it an offset returned |
1003 | * to it earlier by the means of &v4l2_ioctl_ops->vidioc_querybuf handler. |
1004 | * That offset acts as a "cookie", which is then used to identify the plane |
1005 | * to be mapped. |
1006 | * |
1007 | * This function finds a plane with a matching offset and a mapping is performed |
1008 | * by the means of a provided memory operation. |
1009 | * |
1010 | * The return values from this function are intended to be directly returned |
1011 | * from the mmap handler in driver. |
1012 | */ |
1013 | int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); |
1014 | |
1015 | #ifndef CONFIG_MMU |
1016 | /** |
1017 | * vb2_get_unmapped_area - map video buffers into application address space. |
1018 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1019 | * @addr: memory address. |
1020 | * @len: buffer size. |
1021 | * @pgoff: page offset. |
1022 | * @flags: memory flags. |
1023 | * |
1024 | * This function is used in noMMU platforms to propose address mapping |
1025 | * for a given buffer. It's intended to be used as a handler for the |
1026 | * &file_operations->get_unmapped_area operation. |
1027 | * |
1028 | * This is called by the mmap() syscall routines will call this |
1029 | * to get a proposed address for the mapping, when ``!CONFIG_MMU``. |
1030 | */ |
1031 | unsigned long vb2_get_unmapped_area(struct vb2_queue *q, |
1032 | unsigned long addr, |
1033 | unsigned long len, |
1034 | unsigned long pgoff, |
1035 | unsigned long flags); |
1036 | #endif |
1037 | |
1038 | /** |
1039 | * vb2_core_poll() - implements poll syscall() logic. |
1040 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1041 | * @file: &struct file argument passed to the poll |
1042 | * file operation handler. |
1043 | * @wait: &poll_table wait argument passed to the poll |
1044 | * file operation handler. |
1045 | * |
1046 | * This function implements poll file operation handler for a driver. |
1047 | * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will |
1048 | * be informed that the file descriptor of a video device is available for |
1049 | * reading. |
1050 | * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor |
1051 | * will be reported as available for writing. |
1052 | * |
1053 | * The return values from this function are intended to be directly returned |
1054 | * from poll handler in driver. |
1055 | */ |
1056 | __poll_t vb2_core_poll(struct vb2_queue *q, struct file *file, |
1057 | poll_table *wait); |
1058 | |
1059 | /** |
1060 | * vb2_read() - implements read() syscall logic. |
1061 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1062 | * @data: pointed to target userspace buffer |
1063 | * @count: number of bytes to read |
1064 | * @ppos: file handle position tracking pointer |
1065 | * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) |
1066 | */ |
1067 | size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, |
1068 | loff_t *ppos, int nonblock); |
1069 | /** |
1070 | * vb2_write() - implements write() syscall logic. |
1071 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1072 | * @data: pointed to target userspace buffer |
1073 | * @count: number of bytes to write |
1074 | * @ppos: file handle position tracking pointer |
1075 | * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) |
1076 | */ |
1077 | size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, |
1078 | loff_t *ppos, int nonblock); |
1079 | |
1080 | /** |
1081 | * typedef vb2_thread_fnc - callback function for use with vb2_thread. |
1082 | * |
1083 | * @vb: pointer to struct &vb2_buffer. |
1084 | * @priv: pointer to a private data. |
1085 | * |
1086 | * This is called whenever a buffer is dequeued in the thread. |
1087 | */ |
1088 | typedef int (*vb2_thread_fnc)(struct vb2_buffer *vb, void *priv); |
1089 | |
1090 | /** |
1091 | * vb2_thread_start() - start a thread for the given queue. |
1092 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1093 | * @fnc: &vb2_thread_fnc callback function. |
1094 | * @priv: priv pointer passed to the callback function. |
1095 | * @thread_name:the name of the thread. This will be prefixed with "vb2-". |
1096 | * |
1097 | * This starts a thread that will queue and dequeue until an error occurs |
1098 | * or vb2_thread_stop() is called. |
1099 | * |
1100 | * .. attention:: |
1101 | * |
1102 | * This function should not be used for anything else but the videobuf2-dvb |
1103 | * support. If you think you have another good use-case for this, then please |
1104 | * contact the linux-media mailing list first. |
1105 | */ |
1106 | int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, |
1107 | const char *thread_name); |
1108 | |
1109 | /** |
1110 | * vb2_thread_stop() - stop the thread for the given queue. |
1111 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1112 | */ |
1113 | int vb2_thread_stop(struct vb2_queue *q); |
1114 | |
1115 | /** |
1116 | * vb2_is_streaming() - return streaming status of the queue. |
1117 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1118 | */ |
1119 | static inline bool vb2_is_streaming(struct vb2_queue *q) |
1120 | { |
1121 | return q->streaming; |
1122 | } |
1123 | |
1124 | /** |
1125 | * vb2_fileio_is_active() - return true if fileio is active. |
1126 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1127 | * |
1128 | * This returns true if read() or write() is used to stream the data |
1129 | * as opposed to stream I/O. This is almost never an important distinction, |
1130 | * except in rare cases. One such case is that using read() or write() to |
1131 | * stream a format using %V4L2_FIELD_ALTERNATE is not allowed since there |
1132 | * is no way you can pass the field information of each buffer to/from |
1133 | * userspace. A driver that supports this field format should check for |
1134 | * this in the &vb2_ops->queue_setup op and reject it if this function returns |
1135 | * true. |
1136 | */ |
1137 | static inline bool vb2_fileio_is_active(struct vb2_queue *q) |
1138 | { |
1139 | return q->fileio; |
1140 | } |
1141 | |
1142 | /** |
1143 | * vb2_is_busy() - return busy status of the queue. |
1144 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1145 | * |
1146 | * This function checks if queue has any buffers allocated. |
1147 | */ |
1148 | static inline bool vb2_is_busy(struct vb2_queue *q) |
1149 | { |
1150 | return (q->num_buffers > 0); |
1151 | } |
1152 | |
1153 | /** |
1154 | * vb2_get_drv_priv() - return driver private data associated with the queue. |
1155 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1156 | */ |
1157 | static inline void *vb2_get_drv_priv(struct vb2_queue *q) |
1158 | { |
1159 | return q->drv_priv; |
1160 | } |
1161 | |
1162 | /** |
1163 | * vb2_set_plane_payload() - set bytesused for the plane @plane_no. |
1164 | * @vb: pointer to &struct vb2_buffer to which the plane in |
1165 | * question belongs to. |
1166 | * @plane_no: plane number for which payload should be set. |
1167 | * @size: payload in bytes. |
1168 | */ |
1169 | static inline void vb2_set_plane_payload(struct vb2_buffer *vb, |
1170 | unsigned int plane_no, unsigned long size) |
1171 | { |
1172 | /* |
1173 | * size must never be larger than the buffer length, so |
1174 | * warn and clamp to the buffer length if that's the case. |
1175 | */ |
1176 | if (plane_no < vb->num_planes) { |
1177 | if (WARN_ON_ONCE(size > vb->planes[plane_no].length)) |
1178 | size = vb->planes[plane_no].length; |
1179 | vb->planes[plane_no].bytesused = size; |
1180 | } |
1181 | } |
1182 | |
1183 | /** |
1184 | * vb2_get_plane_payload() - get bytesused for the plane plane_no |
1185 | * @vb: pointer to &struct vb2_buffer to which the plane in |
1186 | * question belongs to. |
1187 | * @plane_no: plane number for which payload should be set. |
1188 | */ |
1189 | static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, |
1190 | unsigned int plane_no) |
1191 | { |
1192 | if (plane_no < vb->num_planes) |
1193 | return vb->planes[plane_no].bytesused; |
1194 | return 0; |
1195 | } |
1196 | |
1197 | /** |
1198 | * vb2_plane_size() - return plane size in bytes. |
1199 | * @vb: pointer to &struct vb2_buffer to which the plane in |
1200 | * question belongs to. |
1201 | * @plane_no: plane number for which size should be returned. |
1202 | */ |
1203 | static inline unsigned long |
1204 | vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) |
1205 | { |
1206 | if (plane_no < vb->num_planes) |
1207 | return vb->planes[plane_no].length; |
1208 | return 0; |
1209 | } |
1210 | |
1211 | /** |
1212 | * vb2_start_streaming_called() - return streaming status of driver. |
1213 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1214 | */ |
1215 | static inline bool vb2_start_streaming_called(struct vb2_queue *q) |
1216 | { |
1217 | return q->start_streaming_called; |
1218 | } |
1219 | |
1220 | /** |
1221 | * vb2_clear_last_buffer_dequeued() - clear last buffer dequeued flag of queue. |
1222 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1223 | */ |
1224 | static inline void vb2_clear_last_buffer_dequeued(struct vb2_queue *q) |
1225 | { |
1226 | q->last_buffer_dequeued = false; |
1227 | } |
1228 | |
1229 | /** |
1230 | * vb2_get_buffer() - get a buffer from a queue |
1231 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1232 | * @index: buffer index |
1233 | * |
1234 | * This function obtains a buffer from a queue, by its index. |
1235 | * Keep in mind that there is no refcounting involved in this |
1236 | * operation, so the buffer lifetime should be taken into |
1237 | * consideration. |
1238 | */ |
1239 | static inline struct vb2_buffer *vb2_get_buffer(struct vb2_queue *q, |
1240 | unsigned int index) |
1241 | { |
1242 | if (index < q->num_buffers) |
1243 | return q->bufs[index]; |
1244 | return NULL; |
1245 | } |
1246 | |
1247 | /* |
1248 | * The following functions are not part of the vb2 core API, but are useful |
1249 | * functions for videobuf2-*. |
1250 | */ |
1251 | |
1252 | /** |
1253 | * vb2_buffer_in_use() - return true if the buffer is in use and |
1254 | * the queue cannot be freed (by the means of VIDIOC_REQBUFS(0)) call. |
1255 | * |
1256 | * @vb: buffer for which plane size should be returned. |
1257 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1258 | */ |
1259 | bool vb2_buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb); |
1260 | |
1261 | /** |
1262 | * vb2_verify_memory_type() - Check whether the memory type and buffer type |
1263 | * passed to a buffer operation are compatible with the queue. |
1264 | * |
1265 | * @q: pointer to &struct vb2_queue with videobuf2 queue. |
1266 | * @memory: memory model, as defined by enum &vb2_memory. |
1267 | * @type: private buffer type whose content is defined by the vb2-core |
1268 | * caller. For example, for V4L2, it should match |
1269 | * the types defined on enum &v4l2_buf_type. |
1270 | */ |
1271 | int vb2_verify_memory_type(struct vb2_queue *q, |
1272 | enum vb2_memory memory, unsigned int type); |
1273 | |
1274 | /** |
1275 | * vb2_request_object_is_buffer() - return true if the object is a buffer |
1276 | * |
1277 | * @obj: the request object. |
1278 | */ |
1279 | bool vb2_request_object_is_buffer(struct media_request_object *obj); |
1280 | |
1281 | /** |
1282 | * vb2_request_buffer_cnt() - return the number of buffers in the request |
1283 | * |
1284 | * @req: the request. |
1285 | */ |
1286 | unsigned int vb2_request_buffer_cnt(struct media_request *req); |
1287 | |
1288 | #endif /* _MEDIA_VIDEOBUF2_CORE_H */ |
1289 | |