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1 | /* |
2 | * videobuf2-core.h - V4L2 driver helper framework | |
3 | * | |
4 | * Copyright (C) 2010 Samsung Electronics | |
5 | * | |
95072084 | 6 | * Author: Pawel Osciak <pawel@osciak.com> |
e23ccc0a PO |
7 | * |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation. | |
11 | */ | |
12 | #ifndef _MEDIA_VIDEOBUF2_CORE_H | |
13 | #define _MEDIA_VIDEOBUF2_CORE_H | |
14 | ||
15 | #include <linux/mm_types.h> | |
16 | #include <linux/mutex.h> | |
17 | #include <linux/poll.h> | |
18 | #include <linux/videodev2.h> | |
19 | ||
20 | struct vb2_alloc_ctx; | |
b25748fe | 21 | struct vb2_fileio_data; |
e23ccc0a PO |
22 | |
23 | /** | |
24 | * struct vb2_mem_ops - memory handling/memory allocator operations | |
25 | * @alloc: allocate video memory and, optionally, allocator private data, | |
26 | * return NULL on failure or a pointer to allocator private, | |
27 | * per-buffer data on success; the returned private structure | |
28 | * will then be passed as buf_priv argument to other ops in this | |
29 | * structure | |
30 | * @put: inform the allocator that the buffer will no longer be used; | |
31 | * usually will result in the allocator freeing the buffer (if | |
32 | * no other users of this buffer are present); the buf_priv | |
33 | * argument is the allocator private per-buffer structure | |
34 | * previously returned from the alloc callback | |
35 | * @get_userptr: acquire userspace memory for a hardware operation; used for | |
36 | * USERPTR memory types; vaddr is the address passed to the | |
37 | * videobuf layer when queuing a video buffer of USERPTR type; | |
38 | * should return an allocator private per-buffer structure | |
39 | * associated with the buffer on success, NULL on failure; | |
40 | * the returned private structure will then be passed as buf_priv | |
41 | * argument to other ops in this structure | |
42 | * @put_userptr: inform the allocator that a USERPTR buffer will no longer | |
43 | * be used | |
44 | * @vaddr: return a kernel virtual address to a given memory buffer | |
45 | * associated with the passed private structure or NULL if no | |
46 | * such mapping exists | |
47 | * @cookie: return allocator specific cookie for a given memory buffer | |
48 | * associated with the passed private structure or NULL if not | |
49 | * available | |
50 | * @num_users: return the current number of users of a memory buffer; | |
51 | * return 1 if the videobuf layer (or actually the driver using | |
52 | * it) is the only user | |
53 | * @mmap: setup a userspace mapping for a given memory buffer under | |
54 | * the provided virtual memory region | |
55 | * | |
56 | * Required ops for USERPTR types: get_userptr, put_userptr. | |
57 | * Required ops for MMAP types: alloc, put, num_users, mmap. | |
b25748fe | 58 | * Required ops for read/write access types: alloc, put, num_users, vaddr |
e23ccc0a PO |
59 | */ |
60 | struct vb2_mem_ops { | |
61 | void *(*alloc)(void *alloc_ctx, unsigned long size); | |
62 | void (*put)(void *buf_priv); | |
63 | ||
64 | void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr, | |
65 | unsigned long size, int write); | |
66 | void (*put_userptr)(void *buf_priv); | |
67 | ||
68 | void *(*vaddr)(void *buf_priv); | |
69 | void *(*cookie)(void *buf_priv); | |
70 | ||
71 | unsigned int (*num_users)(void *buf_priv); | |
72 | ||
73 | int (*mmap)(void *buf_priv, struct vm_area_struct *vma); | |
74 | }; | |
75 | ||
76 | struct vb2_plane { | |
77 | void *mem_priv; | |
78 | int mapped:1; | |
79 | }; | |
80 | ||
81 | /** | |
82 | * enum vb2_io_modes - queue access methods | |
83 | * @VB2_MMAP: driver supports MMAP with streaming API | |
84 | * @VB2_USERPTR: driver supports USERPTR with streaming API | |
85 | * @VB2_READ: driver supports read() style access | |
86 | * @VB2_WRITE: driver supports write() style access | |
87 | */ | |
88 | enum vb2_io_modes { | |
89 | VB2_MMAP = (1 << 0), | |
90 | VB2_USERPTR = (1 << 1), | |
91 | VB2_READ = (1 << 2), | |
92 | VB2_WRITE = (1 << 3), | |
93 | }; | |
94 | ||
95 | /** | |
96 | * enum vb2_fileio_flags - flags for selecting a mode of the file io emulator, | |
97 | * by default the 'streaming' style is used by the file io emulator | |
98 | * @VB2_FILEIO_READ_ONCE: report EOF after reading the first buffer | |
99 | * @VB2_FILEIO_WRITE_IMMEDIATELY: queue buffer after each write() call | |
100 | */ | |
101 | enum vb2_fileio_flags { | |
102 | VB2_FILEIO_READ_ONCE = (1 << 0), | |
103 | VB2_FILEIO_WRITE_IMMEDIATELY = (1 << 1), | |
104 | }; | |
105 | ||
106 | /** | |
107 | * enum vb2_buffer_state - current video buffer state | |
108 | * @VB2_BUF_STATE_DEQUEUED: buffer under userspace control | |
109 | * @VB2_BUF_STATE_QUEUED: buffer queued in videobuf, but not in driver | |
110 | * @VB2_BUF_STATE_ACTIVE: buffer queued in driver and possibly used | |
111 | * in a hardware operation | |
112 | * @VB2_BUF_STATE_DONE: buffer returned from driver to videobuf, but | |
113 | * not yet dequeued to userspace | |
114 | * @VB2_BUF_STATE_ERROR: same as above, but the operation on the buffer | |
115 | * has ended with an error, which will be reported | |
116 | * to the userspace when it is dequeued | |
117 | */ | |
118 | enum vb2_buffer_state { | |
119 | VB2_BUF_STATE_DEQUEUED, | |
120 | VB2_BUF_STATE_QUEUED, | |
121 | VB2_BUF_STATE_ACTIVE, | |
122 | VB2_BUF_STATE_DONE, | |
123 | VB2_BUF_STATE_ERROR, | |
124 | }; | |
125 | ||
126 | struct vb2_queue; | |
127 | ||
128 | /** | |
129 | * struct vb2_buffer - represents a video buffer | |
130 | * @v4l2_buf: struct v4l2_buffer associated with this buffer; can | |
131 | * be read by the driver and relevant entries can be | |
132 | * changed by the driver in case of CAPTURE types | |
133 | * (such as timestamp) | |
134 | * @v4l2_planes: struct v4l2_planes associated with this buffer; can | |
135 | * be read by the driver and relevant entries can be | |
136 | * changed by the driver in case of CAPTURE types | |
137 | * (such as bytesused); NOTE that even for single-planar | |
138 | * types, the v4l2_planes[0] struct should be used | |
139 | * instead of v4l2_buf for filling bytesused - drivers | |
140 | * should use the vb2_set_plane_payload() function for that | |
141 | * @vb2_queue: the queue to which this driver belongs | |
142 | * @num_planes: number of planes in the buffer | |
143 | * on an internal driver queue | |
144 | * @state: current buffer state; do not change | |
145 | * @queued_entry: entry on the queued buffers list, which holds all | |
146 | * buffers queued from userspace | |
147 | * @done_entry: entry on the list that stores all buffers ready to | |
148 | * be dequeued to userspace | |
149 | * @planes: private per-plane information; do not change | |
150 | * @num_planes_mapped: number of mapped planes; do not change | |
151 | */ | |
152 | struct vb2_buffer { | |
153 | struct v4l2_buffer v4l2_buf; | |
154 | struct v4l2_plane v4l2_planes[VIDEO_MAX_PLANES]; | |
155 | ||
156 | struct vb2_queue *vb2_queue; | |
157 | ||
158 | unsigned int num_planes; | |
159 | ||
160 | /* Private: internal use only */ | |
161 | enum vb2_buffer_state state; | |
162 | ||
163 | struct list_head queued_entry; | |
164 | struct list_head done_entry; | |
165 | ||
166 | struct vb2_plane planes[VIDEO_MAX_PLANES]; | |
167 | unsigned int num_planes_mapped; | |
168 | }; | |
169 | ||
170 | /** | |
171 | * struct vb2_ops - driver-specific callbacks | |
172 | * | |
173 | * @queue_setup: called from a VIDIOC_REQBUFS handler, before | |
174 | * memory allocation; driver should return the required | |
175 | * number of buffers in num_buffers, the required number | |
176 | * of planes per buffer in num_planes; the size of each | |
177 | * plane should be set in the sizes[] array and optional | |
178 | * per-plane allocator specific context in alloc_ctxs[] | |
179 | * array | |
180 | * @wait_prepare: release any locks taken while calling vb2 functions; | |
181 | * it is called before an ioctl needs to wait for a new | |
182 | * buffer to arrive; required to avoid a deadlock in | |
183 | * blocking access type | |
184 | * @wait_finish: reacquire all locks released in the previous callback; | |
185 | * required to continue operation after sleeping while | |
186 | * waiting for a new buffer to arrive | |
187 | * @buf_init: called once after allocating a buffer (in MMAP case) | |
188 | * or after acquiring a new USERPTR buffer; drivers may | |
189 | * perform additional buffer-related initialization; | |
190 | * initialization failure (return != 0) will prevent | |
191 | * queue setup from completing successfully; optional | |
192 | * @buf_prepare: called every time the buffer is queued from userspace; | |
193 | * drivers may perform any initialization required before | |
194 | * each hardware operation in this callback; | |
195 | * if an error is returned, the buffer will not be queued | |
196 | * in driver; optional | |
197 | * @buf_finish: called before every dequeue of the buffer back to | |
198 | * userspace; drivers may perform any operations required | |
199 | * before userspace accesses the buffer; optional | |
200 | * @buf_cleanup: called once before the buffer is freed; drivers may | |
201 | * perform any additional cleanup; optional | |
202 | * @start_streaming: called once before entering 'streaming' state; enables | |
203 | * driver to receive buffers over buf_queue() callback | |
204 | * @stop_streaming: called when 'streaming' state must be disabled; driver | |
205 | * should stop any DMA transactions or wait until they | |
206 | * finish and give back all buffers it got from buf_queue() | |
207 | * callback; may use vb2_wait_for_all_buffers() function | |
208 | * @buf_queue: passes buffer vb to the driver; driver may start | |
209 | * hardware operation on this buffer; driver should give | |
210 | * the buffer back by calling vb2_buffer_done() function | |
211 | */ | |
212 | struct vb2_ops { | |
213 | int (*queue_setup)(struct vb2_queue *q, unsigned int *num_buffers, | |
214 | unsigned int *num_planes, unsigned long sizes[], | |
215 | void *alloc_ctxs[]); | |
216 | ||
217 | void (*wait_prepare)(struct vb2_queue *q); | |
218 | void (*wait_finish)(struct vb2_queue *q); | |
219 | ||
220 | int (*buf_init)(struct vb2_buffer *vb); | |
221 | int (*buf_prepare)(struct vb2_buffer *vb); | |
222 | int (*buf_finish)(struct vb2_buffer *vb); | |
223 | void (*buf_cleanup)(struct vb2_buffer *vb); | |
224 | ||
225 | int (*start_streaming)(struct vb2_queue *q); | |
226 | int (*stop_streaming)(struct vb2_queue *q); | |
227 | ||
228 | void (*buf_queue)(struct vb2_buffer *vb); | |
229 | }; | |
230 | ||
231 | /** | |
232 | * struct vb2_queue - a videobuf queue | |
233 | * | |
234 | * @type: queue type (see V4L2_BUF_TYPE_* in linux/videodev2.h | |
235 | * @io_modes: supported io methods (see vb2_io_modes enum) | |
236 | * @io_flags: additional io flags (see vb2_fileio_flags enum) | |
237 | * @ops: driver-specific callbacks | |
238 | * @mem_ops: memory allocator specific callbacks | |
239 | * @drv_priv: driver private data | |
240 | * @buf_struct_size: size of the driver-specific buffer structure; | |
241 | * "0" indicates the driver doesn't want to use a custom buffer | |
242 | * structure type, so sizeof(struct vb2_buffer) will is used | |
243 | * | |
244 | * @memory: current memory type used | |
245 | * @bufs: videobuf buffer structures | |
246 | * @num_buffers: number of allocated/used buffers | |
247 | * @queued_list: list of buffers currently queued from userspace | |
248 | * @queued_count: number of buffers owned by the driver | |
249 | * @done_list: list of buffers ready to be dequeued to userspace | |
250 | * @done_lock: lock to protect done_list list | |
251 | * @done_wq: waitqueue for processes waiting for buffers ready to be dequeued | |
252 | * @alloc_ctx: memory type/allocator-specific contexts for each plane | |
253 | * @streaming: current streaming state | |
b25748fe | 254 | * @fileio: file io emulator internal data, used only if emulator is active |
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255 | */ |
256 | struct vb2_queue { | |
257 | enum v4l2_buf_type type; | |
258 | unsigned int io_modes; | |
259 | unsigned int io_flags; | |
260 | ||
261 | const struct vb2_ops *ops; | |
262 | const struct vb2_mem_ops *mem_ops; | |
263 | void *drv_priv; | |
264 | unsigned int buf_struct_size; | |
265 | ||
266 | /* private: internal use only */ | |
267 | enum v4l2_memory memory; | |
268 | struct vb2_buffer *bufs[VIDEO_MAX_FRAME]; | |
269 | unsigned int num_buffers; | |
270 | ||
271 | struct list_head queued_list; | |
272 | ||
273 | atomic_t queued_count; | |
274 | struct list_head done_list; | |
275 | spinlock_t done_lock; | |
276 | wait_queue_head_t done_wq; | |
277 | ||
278 | void *alloc_ctx[VIDEO_MAX_PLANES]; | |
279 | ||
280 | unsigned int streaming:1; | |
b25748fe MS |
281 | |
282 | struct vb2_fileio_data *fileio; | |
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283 | }; |
284 | ||
285 | void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no); | |
286 | void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no); | |
287 | ||
288 | void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state); | |
289 | int vb2_wait_for_all_buffers(struct vb2_queue *q); | |
290 | ||
291 | int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b); | |
292 | int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req); | |
293 | ||
294 | int vb2_queue_init(struct vb2_queue *q); | |
295 | ||
296 | void vb2_queue_release(struct vb2_queue *q); | |
297 | ||
298 | int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b); | |
299 | int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking); | |
300 | ||
301 | int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type); | |
302 | int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type); | |
303 | ||
304 | int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma); | |
305 | unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait); | |
b25748fe MS |
306 | size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, |
307 | loff_t *ppos, int nonblock); | |
308 | size_t vb2_write(struct vb2_queue *q, char __user *data, size_t count, | |
309 | loff_t *ppos, int nonblock); | |
e23ccc0a PO |
310 | |
311 | /** | |
312 | * vb2_is_streaming() - return streaming status of the queue | |
313 | * @q: videobuf queue | |
314 | */ | |
315 | static inline bool vb2_is_streaming(struct vb2_queue *q) | |
316 | { | |
317 | return q->streaming; | |
318 | } | |
319 | ||
320 | /** | |
321 | * vb2_is_busy() - return busy status of the queue | |
322 | * @q: videobuf queue | |
323 | * | |
324 | * This function checks if queue has any buffers allocated. | |
325 | */ | |
326 | static inline bool vb2_is_busy(struct vb2_queue *q) | |
327 | { | |
328 | return (q->num_buffers > 0); | |
329 | } | |
330 | ||
331 | /** | |
332 | * vb2_get_drv_priv() - return driver private data associated with the queue | |
333 | * @q: videobuf queue | |
334 | */ | |
335 | static inline void *vb2_get_drv_priv(struct vb2_queue *q) | |
336 | { | |
337 | return q->drv_priv; | |
338 | } | |
339 | ||
340 | /** | |
341 | * vb2_set_plane_payload() - set bytesused for the plane plane_no | |
342 | * @vb: buffer for which plane payload should be set | |
343 | * @plane_no: plane number for which payload should be set | |
344 | * @size: payload in bytes | |
345 | */ | |
346 | static inline void vb2_set_plane_payload(struct vb2_buffer *vb, | |
347 | unsigned int plane_no, unsigned long size) | |
348 | { | |
349 | if (plane_no < vb->num_planes) | |
350 | vb->v4l2_planes[plane_no].bytesused = size; | |
351 | } | |
352 | ||
353 | /** | |
9f00edae | 354 | * vb2_get_plane_payload() - get bytesused for the plane plane_no |
e23ccc0a PO |
355 | * @vb: buffer for which plane payload should be set |
356 | * @plane_no: plane number for which payload should be set | |
357 | * @size: payload in bytes | |
358 | */ | |
359 | static inline unsigned long vb2_get_plane_payload(struct vb2_buffer *vb, | |
360 | unsigned int plane_no) | |
361 | { | |
362 | if (plane_no < vb->num_planes) | |
363 | return vb->v4l2_planes[plane_no].bytesused; | |
364 | return 0; | |
365 | } | |
366 | ||
367 | /** | |
368 | * vb2_plane_size() - return plane size in bytes | |
369 | * @vb: buffer for which plane size should be returned | |
370 | * @plane_no: plane number for which size should be returned | |
371 | */ | |
372 | static inline unsigned long | |
373 | vb2_plane_size(struct vb2_buffer *vb, unsigned int plane_no) | |
374 | { | |
375 | if (plane_no < vb->num_planes) | |
376 | return vb->v4l2_planes[plane_no].length; | |
377 | return 0; | |
378 | } | |
379 | ||
380 | #endif /* _MEDIA_VIDEOBUF2_CORE_H */ |