2 * Memory-to-memory device framework for Video for Linux 2.
4 * Helper functions for devices that use memory buffers for both source
7 * Copyright (c) 2009 Samsung Electronics Co., Ltd.
8 * Pawel Osciak, <pawel@osciak.com>
9 * Marek Szyprowski, <m.szyprowski@samsung.com>
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by the
13 * Free Software Foundation; either version 2 of the
14 * License, or (at your option) any later version
17 #ifndef _MEDIA_V4L2_MEM2MEM_H
18 #define _MEDIA_V4L2_MEM2MEM_H
20 #include <media/videobuf2-v4l2.h>
23 * struct v4l2_m2m_ops - mem-to-mem device driver callbacks
24 * @device_run: required. Begin the actual job (transaction) inside this
26 * The job does NOT have to end before this callback returns
27 * (and it will be the usual case). When the job finishes,
28 * v4l2_m2m_job_finish() has to be called.
29 * @job_ready: optional. Should return 0 if the driver does not have a job
30 * fully prepared to run yet (i.e. it will not be able to finish a
31 * transaction without sleeping). If not provided, it will be
32 * assumed that one source and one destination buffer are all
33 * that is required for the driver to perform one full transaction.
34 * This method may not sleep.
35 * @job_abort: required. Informs the driver that it has to abort the currently
36 * running transaction as soon as possible (i.e. as soon as it can
37 * stop the device safely; e.g. in the next interrupt handler),
38 * even if the transaction would not have been finished by then.
39 * After the driver performs the necessary steps, it has to call
40 * v4l2_m2m_job_finish() (as if the transaction ended normally).
41 * This function does not have to (and will usually not) wait
42 * until the device enters a state when it can be stopped.
43 * @lock: optional. Define a driver's own lock callback, instead of using
44 * &v4l2_m2m_ctx->q_lock.
45 * @unlock: optional. Define a driver's own unlock callback, instead of
46 * using &v4l2_m2m_ctx->q_lock.
49 void (*device_run)(void *priv);
50 int (*job_ready)(void *priv);
51 void (*job_abort)(void *priv);
52 void (*lock)(void *priv);
53 void (*unlock)(void *priv);
57 * struct v4l2_m2m_dev - opaque struct used to represent a V4L2 M2M device.
59 * This structure is has the per-device context for a memory to memory
60 * device, and it is used internally at v4l2-mem2mem.c.
65 * struct v4l2_m2m_queue_ctx - represents a queue for buffers ready to be
68 * @q: pointer to struct &vb2_queue
69 * @rdy_queue: List of V4L2 mem-to-mem queues
70 * @rdy_spinlock: spin lock to protect the struct usage
71 * @num_rdy: number of buffers ready to be processed
72 * @buffered: is the queue buffered?
74 * Queue for buffers ready to be processed as soon as this
75 * instance receives access to the device.
78 struct v4l2_m2m_queue_ctx {
81 struct list_head rdy_queue;
82 spinlock_t rdy_spinlock;
88 * struct v4l2_m2m_ctx - Memory to memory context structure
90 * @q_lock: struct &mutex lock
91 * @m2m_dev: pointer to struct &v4l2_m2m_dev
92 * @cap_q_ctx: Capture (output to memory) queue context
93 * @out_q_ctx: Output (input from memory) queue context
94 * @queue: List of memory to memory contexts
95 * @job_flags: Job queue flags, used internally by v4l2-mem2mem.c:
96 * %TRANS_QUEUED, %TRANS_RUNNING and %TRANS_ABORT.
97 * @finished: Wait queue used to signalize when a job queue finished.
98 * @priv: Instance private data
100 struct v4l2_m2m_ctx {
101 /* optional cap/out vb2 queues lock */
102 struct mutex *q_lock;
104 /* internal use only */
105 struct v4l2_m2m_dev *m2m_dev;
107 struct v4l2_m2m_queue_ctx cap_q_ctx;
109 struct v4l2_m2m_queue_ctx out_q_ctx;
111 /* For device job queue */
112 struct list_head queue;
113 unsigned long job_flags;
114 wait_queue_head_t finished;
120 * struct v4l2_m2m_buffer - Memory to memory buffer
122 * @vb: pointer to struct &vb2_v4l2_buffer
123 * @list: list of m2m buffers
125 struct v4l2_m2m_buffer {
126 struct vb2_v4l2_buffer vb;
127 struct list_head list;
131 * v4l2_m2m_get_curr_priv() - return driver private data for the currently
132 * running instance or NULL if no instance is running
134 * @m2m_dev: pointer to struct &v4l2_m2m_dev
136 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);
139 * v4l2_m2m_get_vq() - return vb2_queue for the given type
141 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
142 * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type
144 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
145 enum v4l2_buf_type type);
148 * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
149 * the pending job queue and add it if so.
151 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
153 * There are three basic requirements an instance has to meet to be able to run:
154 * 1) at least one source buffer has to be queued,
155 * 2) at least one destination buffer has to be queued,
156 * 3) streaming has to be on.
158 * If a queue is buffered (for example a decoder hardware ringbuffer that has
159 * to be drained before doing streamoff), allow scheduling without v4l2 buffers
162 * There may also be additional, custom requirements. In such case the driver
163 * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
164 * return 1 if the instance is ready.
165 * An example of the above could be an instance that requires more than one
166 * src/dst buffer per transaction.
168 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx);
171 * v4l2_m2m_job_finish() - inform the framework that a job has been finished
172 * and have it clean up
174 * @m2m_dev: pointer to struct &v4l2_m2m_dev
175 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
177 * Called by a driver to yield back the device after it has finished with it.
178 * Should be called as soon as possible after reaching a state which allows
179 * other instances to take control of the device.
181 * This function has to be called only after &v4l2_m2m_ops->device_run
182 * callback has been called on the driver. To prevent recursion, it should
183 * not be called directly from the &v4l2_m2m_ops->device_run callback though.
185 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
186 struct v4l2_m2m_ctx *m2m_ctx);
189 v4l2_m2m_buf_done(struct vb2_v4l2_buffer *buf, enum vb2_buffer_state state)
191 vb2_buffer_done(&buf->vb2_buf, state);
195 * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
197 * @file: pointer to struct &file
198 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
199 * @reqbufs: pointer to struct &v4l2_requestbuffers
201 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
202 struct v4l2_requestbuffers *reqbufs);
205 * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
207 * @file: pointer to struct &file
208 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
209 * @buf: pointer to struct &v4l2_buffer
211 * See v4l2_m2m_mmap() documentation for details.
213 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
214 struct v4l2_buffer *buf);
217 * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
220 * @file: pointer to struct &file
221 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
222 * @buf: pointer to struct &v4l2_buffer
224 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
225 struct v4l2_buffer *buf);
228 * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
231 * @file: pointer to struct &file
232 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
233 * @buf: pointer to struct &v4l2_buffer
235 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
236 struct v4l2_buffer *buf);
239 * v4l2_m2m_prepare_buf() - prepare a source or destination buffer, depending on
242 * @file: pointer to struct &file
243 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
244 * @buf: pointer to struct &v4l2_buffer
246 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
247 struct v4l2_buffer *buf);
250 * v4l2_m2m_create_bufs() - create a source or destination buffer, depending
253 * @file: pointer to struct &file
254 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
255 * @create: pointer to struct &v4l2_create_buffers
257 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
258 struct v4l2_create_buffers *create);
261 * v4l2_m2m_expbuf() - export a source or destination buffer, depending on
264 * @file: pointer to struct &file
265 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
266 * @eb: pointer to struct &v4l2_exportbuffer
268 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
269 struct v4l2_exportbuffer *eb);
272 * v4l2_m2m_streamon() - turn on streaming for a video queue
274 * @file: pointer to struct &file
275 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
276 * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type
278 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
279 enum v4l2_buf_type type);
282 * v4l2_m2m_streamoff() - turn off streaming for a video queue
284 * @file: pointer to struct &file
285 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
286 * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type
288 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
289 enum v4l2_buf_type type);
292 * v4l2_m2m_poll() - poll replacement, for destination buffers only
294 * @file: pointer to struct &file
295 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
296 * @wait: pointer to struct &poll_table_struct
298 * Call from the driver's poll() function. Will poll both queues. If a buffer
299 * is available to dequeue (with dqbuf) from the source queue, this will
300 * indicate that a non-blocking write can be performed, while read will be
301 * returned in case of the destination queue.
303 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
304 struct poll_table_struct *wait);
307 * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
309 * @file: pointer to struct &file
310 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
311 * @vma: pointer to struct &vm_area_struct
313 * Call from driver's mmap() function. Will handle mmap() for both queues
314 * seamlessly for videobuffer, which will receive normal per-queue offsets and
315 * proper videobuf queue pointers. The differentiation is made outside videobuf
316 * by adding a predefined offset to buffers from one of the queues and
317 * subtracting it before passing it back to videobuf. Only drivers (and
318 * thus applications) receive modified offsets.
320 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
321 struct vm_area_struct *vma);
324 * v4l2_m2m_init() - initialize per-driver m2m data
326 * @m2m_ops: pointer to struct v4l2_m2m_ops
328 * Usually called from driver's ``probe()`` function.
330 * Return: returns an opaque pointer to the internal data to handle M2M context
332 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops);
335 * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
337 * @m2m_dev: pointer to struct &v4l2_m2m_dev
339 * Usually called from driver's ``remove()`` function.
341 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev);
344 * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
346 * @m2m_dev: a previously initialized m2m_dev struct
347 * @drv_priv: driver's instance private data
348 * @queue_init: a callback for queue type-specific initialization function
349 * to be used for initializing videobuf_queues
351 * Usually called from driver's ``open()`` function.
353 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
355 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq));
357 static inline void v4l2_m2m_set_src_buffered(struct v4l2_m2m_ctx *m2m_ctx,
360 m2m_ctx->out_q_ctx.buffered = buffered;
363 static inline void v4l2_m2m_set_dst_buffered(struct v4l2_m2m_ctx *m2m_ctx,
366 m2m_ctx->cap_q_ctx.buffered = buffered;
370 * v4l2_m2m_ctx_release() - release m2m context
372 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
374 * Usually called from driver's release() function.
376 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);
379 * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
381 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
382 * @vbuf: pointer to struct &vb2_v4l2_buffer
384 * Call from videobuf_queue_ops->ops->buf_queue, videobuf_queue_ops callback.
386 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
387 struct vb2_v4l2_buffer *vbuf);
390 * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for
393 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
396 unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
398 return m2m_ctx->out_q_ctx.num_rdy;
402 * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers
405 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
408 unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
410 return m2m_ctx->cap_q_ctx.num_rdy;
414 * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
416 * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx
418 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
421 * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
424 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
426 static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
428 return v4l2_m2m_next_buf(&m2m_ctx->out_q_ctx);
432 * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
435 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
437 static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
439 return v4l2_m2m_next_buf(&m2m_ctx->cap_q_ctx);
443 * v4l2_m2m_get_src_vq() - return vb2_queue for source buffers
445 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
448 struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
450 return &m2m_ctx->out_q_ctx.q;
454 * v4l2_m2m_get_dst_vq() - return vb2_queue for destination buffers
456 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
459 struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
461 return &m2m_ctx->cap_q_ctx.q;
465 * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
468 * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx
470 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
473 * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
474 * buffers and return it
476 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
478 static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
480 return v4l2_m2m_buf_remove(&m2m_ctx->out_q_ctx);
484 * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
485 * ready buffers and return it
487 * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
489 static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
491 return v4l2_m2m_buf_remove(&m2m_ctx->cap_q_ctx);
494 /* v4l2 ioctl helpers */
496 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
497 struct v4l2_requestbuffers *rb);
498 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *fh,
499 struct v4l2_create_buffers *create);
500 int v4l2_m2m_ioctl_querybuf(struct file *file, void *fh,
501 struct v4l2_buffer *buf);
502 int v4l2_m2m_ioctl_expbuf(struct file *file, void *fh,
503 struct v4l2_exportbuffer *eb);
504 int v4l2_m2m_ioctl_qbuf(struct file *file, void *fh,
505 struct v4l2_buffer *buf);
506 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *fh,
507 struct v4l2_buffer *buf);
508 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *fh,
509 struct v4l2_buffer *buf);
510 int v4l2_m2m_ioctl_streamon(struct file *file, void *fh,
511 enum v4l2_buf_type type);
512 int v4l2_m2m_ioctl_streamoff(struct file *file, void *fh,
513 enum v4l2_buf_type type);
514 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma);
515 unsigned int v4l2_m2m_fop_poll(struct file *file, poll_table *wait);
517 #endif /* _MEDIA_V4L2_MEM2MEM_H */