include/media/v4l2-mem2mem.h

   1 /*
   2  * Memory-to-memory device framework for Video for Linux 2.
   3  *
   4  * Helper functions for devices that use memory buffers for both source
   5  * and destination.
   6  *
   7  * Copyright (c) 2009 Samsung Electronics Co., Ltd.
   8  * Pawel Osciak, <pawel@osciak.com>
   9  * Marek Szyprowski, <m.szyprowski@samsung.com>
  10  *
  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
  15  */
  16
  17 #ifndef _MEDIA_V4L2_MEM2MEM_H
  18 #define _MEDIA_V4L2_MEM2MEM_H
  19
  20 #include <media/videobuf2-v4l2.h>
  21
  22 /**
  23  * struct v4l2_m2m_ops - mem-to-mem device driver callbacks
  24  * @device_run: required. Begin the actual job (transaction) inside this
  25  *              callback.
  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.
  47  */
  48 struct v4l2_m2m_ops {
  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);
  54 };
  55
  56 struct v4l2_m2m_dev;
  57
  58 /**
  59  * struct v4l2_m2m_queue_ctx - represents a queue for buffers ready to be
  60  *      processed
  61  *
  62  * @q:          pointer to struct &vb2_queue
  63  * @rdy_queue:  List of V4L2 mem-to-mem queues
  64  * @rdy_spinlock: spin lock to protect the struct usage
  65  * @num_rdy:    number of buffers ready to be processed
  66  * @buffered:   is the queue buffered?
  67  *
  68  * Queue for buffers ready to be processed as soon as this
  69  * instance receives access to the device.
  70  */
  71
  72 struct v4l2_m2m_queue_ctx {
  73         struct vb2_queue        q;
  74
  75         struct list_head        rdy_queue;
  76         spinlock_t              rdy_spinlock;
  77         u8                      num_rdy;
  78         bool                    buffered;
  79 };
  80
  81 /**
  82  * struct v4l2_m2m_ctx - Memory to memory context structure
  83  *
  84  * @q_lock: struct &mutex lock
  85  * @m2m_dev: opaque pointer to the internal data to handle M2M context
  86  * @cap_q_ctx: Capture (output to memory) queue context
  87  * @out_q_ctx: Output (input from memory) queue context
  88  * @queue: List of memory to memory contexts
  89  * @job_flags: Job queue flags, used internally by v4l2-mem2mem.c:
  90  *              %TRANS_QUEUED, %TRANS_RUNNING and %TRANS_ABORT.
  91  * @finished: Wait queue used to signalize when a job queue finished.
  92  * @priv: Instance private data
  93  */
  94 struct v4l2_m2m_ctx {
  95         /* optional cap/out vb2 queues lock */
  96         struct mutex                    *q_lock;
  97
  98         /* internal use only */
  99         struct v4l2_m2m_dev             *m2m_dev;
 100
 101         struct v4l2_m2m_queue_ctx       cap_q_ctx;
 102
 103         struct v4l2_m2m_queue_ctx       out_q_ctx;
 104
 105         /* For device job queue */
 106         struct list_head                queue;
 107         unsigned long                   job_flags;
 108         wait_queue_head_t               finished;
 109
 110         void                            *priv;
 111 };
 112
 113 /**
 114  * struct v4l2_m2m_buffer - Memory to memory buffer
 115  *
 116  * @vb: pointer to struct &vb2_v4l2_buffer
 117  * @list: list of m2m buffers
 118  */
 119 struct v4l2_m2m_buffer {
 120         struct vb2_v4l2_buffer  vb;
 121         struct list_head        list;
 122 };
 123
 124 /**
 125  * v4l2_m2m_get_curr_priv() - return driver private data for the currently
 126  * running instance or NULL if no instance is running
 127  *
 128  * @m2m_dev: opaque pointer to the internal data to handle M2M context
 129  */
 130 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev);
 131
 132 /**
 133  * v4l2_m2m_get_vq() - return vb2_queue for the given type
 134  *
 135  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 136  * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type
 137  */
 138 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
 139                                        enum v4l2_buf_type type);
 140
 141 /**
 142  * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
 143  * the pending job queue and add it if so.
 144  *
 145  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 146  *
 147  * There are three basic requirements an instance has to meet to be able to run:
 148  * 1) at least one source buffer has to be queued,
 149  * 2) at least one destination buffer has to be queued,
 150  * 3) streaming has to be on.
 151  *
 152  * If a queue is buffered (for example a decoder hardware ringbuffer that has
 153  * to be drained before doing streamoff), allow scheduling without v4l2 buffers
 154  * on that queue.
 155  *
 156  * There may also be additional, custom requirements. In such case the driver
 157  * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
 158  * return 1 if the instance is ready.
 159  * An example of the above could be an instance that requires more than one
 160  * src/dst buffer per transaction.
 161  */
 162 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx);
 163
 164 /**
 165  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
 166  * and have it clean up
 167  *
 168  * @m2m_dev: opaque pointer to the internal data to handle M2M context
 169  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 170  *
 171  * Called by a driver to yield back the device after it has finished with it.
 172  * Should be called as soon as possible after reaching a state which allows
 173  * other instances to take control of the device.
 174  *
 175  * This function has to be called only after &v4l2_m2m_ops->device_run
 176  * callback has been called on the driver. To prevent recursion, it should
 177  * not be called directly from the &v4l2_m2m_ops->device_run callback though.
 178  */
 179 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 180                          struct v4l2_m2m_ctx *m2m_ctx);
 181
 182 static inline void
 183 v4l2_m2m_buf_done(struct vb2_v4l2_buffer *buf, enum vb2_buffer_state state)
 184 {
 185         vb2_buffer_done(&buf->vb2_buf, state);
 186 }
 187
 188 /**
 189  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
 190  *
 191  * @file: pointer to struct &file
 192  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 193  * @reqbufs: pointer to struct &v4l2_requestbuffers
 194  */
 195 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 196                      struct v4l2_requestbuffers *reqbufs);
 197
 198 /**
 199  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
 200  *
 201  * @file: pointer to struct &file
 202  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 203  * @buf: pointer to struct &v4l2_buffer
 204  *
 205  * See v4l2_m2m_mmap() documentation for details.
 206  */
 207 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 208                       struct v4l2_buffer *buf);
 209
 210 /**
 211  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
 212  * the type
 213  *
 214  * @file: pointer to struct &file
 215  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 216  * @buf: pointer to struct &v4l2_buffer
 217  */
 218 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 219                   struct v4l2_buffer *buf);
 220
 221 /**
 222  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
 223  * the type
 224  *
 225  * @file: pointer to struct &file
 226  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 227  * @buf: pointer to struct &v4l2_buffer
 228  */
 229 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 230                    struct v4l2_buffer *buf);
 231
 232 /**
 233  * v4l2_m2m_prepare_buf() - prepare a source or destination buffer, depending on
 234  * the type
 235  *
 236  * @file: pointer to struct &file
 237  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 238  * @buf: pointer to struct &v4l2_buffer
 239  */
 240 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 241                          struct v4l2_buffer *buf);
 242
 243 /**
 244  * v4l2_m2m_create_bufs() - create a source or destination buffer, depending
 245  * on the type
 246  *
 247  * @file: pointer to struct &file
 248  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 249  * @create: pointer to struct &v4l2_create_buffers
 250  */
 251 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 252                          struct v4l2_create_buffers *create);
 253
 254 /**
 255  * v4l2_m2m_expbuf() - export a source or destination buffer, depending on
 256  * the type
 257  *
 258  * @file: pointer to struct &file
 259  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 260  * @eb: pointer to struct &v4l2_exportbuffer
 261  */
 262 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 263                    struct v4l2_exportbuffer *eb);
 264
 265 /**
 266  * v4l2_m2m_streamon() - turn on streaming for a video queue
 267  *
 268  * @file: pointer to struct &file
 269  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 270  * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type
 271  */
 272 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 273                       enum v4l2_buf_type type);
 274
 275 /**
 276  * v4l2_m2m_streamoff() - turn off streaming for a video queue
 277  *
 278  * @file: pointer to struct &file
 279  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 280  * @type: type of the V4L2 buffer, as defined by enum &v4l2_buf_type
 281  */
 282 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 283                        enum v4l2_buf_type type);
 284
 285 /**
 286  * v4l2_m2m_poll() - poll replacement, for destination buffers only
 287  *
 288  * @file: pointer to struct &file
 289  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 290  * @wait: pointer to struct &poll_table_struct
 291  *
 292  * Call from the driver's poll() function. Will poll both queues. If a buffer
 293  * is available to dequeue (with dqbuf) from the source queue, this will
 294  * indicate that a non-blocking write can be performed, while read will be
 295  * returned in case of the destination queue.
 296  */
 297 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 298                            struct poll_table_struct *wait);
 299
 300 /**
 301  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
 302  *
 303  * @file: pointer to struct &file
 304  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 305  * @vma: pointer to struct &vm_area_struct
 306  *
 307  * Call from driver's mmap() function. Will handle mmap() for both queues
 308  * seamlessly for videobuffer, which will receive normal per-queue offsets and
 309  * proper videobuf queue pointers. The differentiation is made outside videobuf
 310  * by adding a predefined offset to buffers from one of the queues and
 311  * subtracting it before passing it back to videobuf. Only drivers (and
 312  * thus applications) receive modified offsets.
 313  */
 314 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 315                   struct vm_area_struct *vma);
 316
 317 /**
 318  * v4l2_m2m_init() - initialize per-driver m2m data
 319  *
 320  * @m2m_ops: pointer to struct v4l2_m2m_ops
 321  *
 322  * Usually called from driver's ``probe()`` function.
 323  *
 324  * Return: returns an opaque pointer to the internal data to handle M2M context
 325  */
 326 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops);
 327
 328 /**
 329  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
 330  *
 331  * @m2m_dev: opaque pointer to the internal data to handle M2M context
 332  *
 333  * Usually called from driver's ``remove()`` function.
 334  */
 335 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev);
 336
 337 /**
 338  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
 339  *
 340  * @m2m_dev: opaque pointer to the internal data to handle M2M context
 341  * @drv_priv: driver's instance private data
 342  * @queue_init: a callback for queue type-specific initialization function
 343  *      to be used for initializing videobuf_queues
 344  *
 345  * Usually called from driver's ``open()`` function.
 346  */
 347 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 348                 void *drv_priv,
 349                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq));
 350
 351 static inline void v4l2_m2m_set_src_buffered(struct v4l2_m2m_ctx *m2m_ctx,
 352                                              bool buffered)
 353 {
 354         m2m_ctx->out_q_ctx.buffered = buffered;
 355 }
 356
 357 static inline void v4l2_m2m_set_dst_buffered(struct v4l2_m2m_ctx *m2m_ctx,
 358                                              bool buffered)
 359 {
 360         m2m_ctx->cap_q_ctx.buffered = buffered;
 361 }
 362
 363 /**
 364  * v4l2_m2m_ctx_release() - release m2m context
 365  *
 366  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 367  *
 368  * Usually called from driver's release() function.
 369  */
 370 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx);
 371
 372 /**
 373  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
 374  *
 375  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 376  * @vbuf: pointer to struct &vb2_v4l2_buffer
 377  *
 378  * Call from videobuf_queue_ops->ops->buf_queue, videobuf_queue_ops callback.
 379  */
 380 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
 381                         struct vb2_v4l2_buffer *vbuf);
 382
 383 /**
 384  * v4l2_m2m_num_src_bufs_ready() - return the number of source buffers ready for
 385  * use
 386  *
 387  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 388  */
 389 static inline
 390 unsigned int v4l2_m2m_num_src_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
 391 {
 392         return m2m_ctx->out_q_ctx.num_rdy;
 393 }
 394
 395 /**
 396  * v4l2_m2m_num_src_bufs_ready() - return the number of destination buffers
 397  * ready for use
 398  *
 399  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 400  */
 401 static inline
 402 unsigned int v4l2_m2m_num_dst_bufs_ready(struct v4l2_m2m_ctx *m2m_ctx)
 403 {
 404         return m2m_ctx->cap_q_ctx.num_rdy;
 405 }
 406
 407 /**
 408  * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
 409  *
 410  * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx
 411  */
 412 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx);
 413
 414 /**
 415  * v4l2_m2m_next_src_buf() - return next source buffer from the list of ready
 416  * buffers
 417  *
 418  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 419  */
 420 static inline void *v4l2_m2m_next_src_buf(struct v4l2_m2m_ctx *m2m_ctx)
 421 {
 422         return v4l2_m2m_next_buf(&m2m_ctx->out_q_ctx);
 423 }
 424
 425 /**
 426  * v4l2_m2m_next_dst_buf() - return next destination buffer from the list of
 427  * ready buffers
 428  *
 429  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 430  */
 431 static inline void *v4l2_m2m_next_dst_buf(struct v4l2_m2m_ctx *m2m_ctx)
 432 {
 433         return v4l2_m2m_next_buf(&m2m_ctx->cap_q_ctx);
 434 }
 435
 436 /**
 437  * v4l2_m2m_get_src_vq() - return vb2_queue for source buffers
 438  *
 439  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 440  */
 441 static inline
 442 struct vb2_queue *v4l2_m2m_get_src_vq(struct v4l2_m2m_ctx *m2m_ctx)
 443 {
 444         return &m2m_ctx->out_q_ctx.q;
 445 }
 446
 447 /**
 448  * v4l2_m2m_get_dst_vq() - return vb2_queue for destination buffers
 449  *
 450  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 451  */
 452 static inline
 453 struct vb2_queue *v4l2_m2m_get_dst_vq(struct v4l2_m2m_ctx *m2m_ctx)
 454 {
 455         return &m2m_ctx->cap_q_ctx.q;
 456 }
 457
 458 /**
 459  * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
 460  * return it
 461  *
 462  * @q_ctx: pointer to struct @v4l2_m2m_queue_ctx
 463  */
 464 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx);
 465
 466 /**
 467  * v4l2_m2m_src_buf_remove() - take off a source buffer from the list of ready
 468  * buffers and return it
 469  *
 470  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 471  */
 472 static inline void *v4l2_m2m_src_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
 473 {
 474         return v4l2_m2m_buf_remove(&m2m_ctx->out_q_ctx);
 475 }
 476
 477 /**
 478  * v4l2_m2m_dst_buf_remove() - take off a destination buffer from the list of
 479  * ready buffers and return it
 480  *
 481  * @m2m_ctx: m2m context assigned to the instance given by struct &v4l2_m2m_ctx
 482  */
 483 static inline void *v4l2_m2m_dst_buf_remove(struct v4l2_m2m_ctx *m2m_ctx)
 484 {
 485         return v4l2_m2m_buf_remove(&m2m_ctx->cap_q_ctx);
 486 }
 487
 488 /* v4l2 ioctl helpers */
 489
 490 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
 491                                 struct v4l2_requestbuffers *rb);
 492 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *fh,
 493                                 struct v4l2_create_buffers *create);
 494 int v4l2_m2m_ioctl_querybuf(struct file *file, void *fh,
 495                                 struct v4l2_buffer *buf);
 496 int v4l2_m2m_ioctl_expbuf(struct file *file, void *fh,
 497                                 struct v4l2_exportbuffer *eb);
 498 int v4l2_m2m_ioctl_qbuf(struct file *file, void *fh,
 499                                 struct v4l2_buffer *buf);
 500 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *fh,
 501                                 struct v4l2_buffer *buf);
 502 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *fh,
 503                                struct v4l2_buffer *buf);
 504 int v4l2_m2m_ioctl_streamon(struct file *file, void *fh,
 505                                 enum v4l2_buf_type type);
 506 int v4l2_m2m_ioctl_streamoff(struct file *file, void *fh,
 507                                 enum v4l2_buf_type type);
 508 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma);
 509 unsigned int v4l2_m2m_fop_poll(struct file *file, poll_table *wait);
 510
 511 #endif /* _MEDIA_V4L2_MEM2MEM_H */
 512