drivers/media/video/v4l2-mem2mem.c

   1 /*
   2  * Memory-to-memory device framework for Video for Linux 2 and videobuf.
   3  *
   4  * Helper functions for devices that use videobuf buffers for both their
   5  * source and destination.
   6  *
   7  * Copyright (c) 2009-2010 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 License, or (at your
  14  * option) any later version.
  15  */
  16 #include <linux/module.h>
  17 #include <linux/sched.h>
  18 #include <linux/slab.h>
  19
  20 #include <media/videobuf2-core.h>
  21 #include <media/v4l2-mem2mem.h>
  22
  23 MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
  24 MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
  25 MODULE_LICENSE("GPL");
  26
  27 static bool debug;
  28 module_param(debug, bool, 0644);
  29
  30 #define dprintk(fmt, arg...)                                            \
  31         do {                                                            \
  32                 if (debug)                                              \
  33                         printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
  34         } while (0)
  35
  36 /* Instance is already queued on the job_queue */
  37 #define TRANS_QUEUED            (1 << 0)
  38 /* Instance is currently running in hardware */
  39 #define TRANS_RUNNING           (1 << 1)
  40
  41
  42 /* Offset base for buffers on the destination queue - used to distinguish
  43  * between source and destination buffers when mmapping - they receive the same
  44  * offsets but for different queues */
  45 #define DST_QUEUE_OFF_BASE      (1 << 30)
  46
  47
  48 /**
  49  * struct v4l2_m2m_dev - per-device context
  50  * @curr_ctx:           currently running instance
  51  * @job_queue:          instances queued to run
  52  * @job_spinlock:       protects job_queue
  53  * @m2m_ops:            driver callbacks
  54  */
  55 struct v4l2_m2m_dev {
  56         struct v4l2_m2m_ctx     *curr_ctx;
  57
  58         struct list_head        job_queue;
  59         spinlock_t              job_spinlock;
  60
  61         struct v4l2_m2m_ops     *m2m_ops;
  62 };
  63
  64 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
  65                                                 enum v4l2_buf_type type)
  66 {
  67         if (V4L2_TYPE_IS_OUTPUT(type))
  68                 return &m2m_ctx->out_q_ctx;
  69         else
  70                 return &m2m_ctx->cap_q_ctx;
  71 }
  72
  73 /**
  74  * v4l2_m2m_get_vq() - return vb2_queue for the given type
  75  */
  76 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
  77                                        enum v4l2_buf_type type)
  78 {
  79         struct v4l2_m2m_queue_ctx *q_ctx;
  80
  81         q_ctx = get_queue_ctx(m2m_ctx, type);
  82         if (!q_ctx)
  83                 return NULL;
  84
  85         return &q_ctx->q;
  86 }
  87 EXPORT_SYMBOL(v4l2_m2m_get_vq);
  88
  89 /**
  90  * v4l2_m2m_next_buf() - return next buffer from the list of ready buffers
  91  */
  92 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
  93 {
  94         struct v4l2_m2m_buffer *b = NULL;
  95         unsigned long flags;
  96
  97         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
  98
  99         if (list_empty(&q_ctx->rdy_queue)) {
 100                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 101                 return NULL;
 102         }
 103
 104         b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
 105         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 106         return &b->vb;
 107 }
 108 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
 109
 110 /**
 111  * v4l2_m2m_buf_remove() - take off a buffer from the list of ready buffers and
 112  * return it
 113  */
 114 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
 115 {
 116         struct v4l2_m2m_buffer *b = NULL;
 117         unsigned long flags;
 118
 119         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 120         if (list_empty(&q_ctx->rdy_queue)) {
 121                 spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 122                 return NULL;
 123         }
 124         b = list_entry(q_ctx->rdy_queue.next, struct v4l2_m2m_buffer, list);
 125         list_del(&b->list);
 126         q_ctx->num_rdy--;
 127         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 128
 129         return &b->vb;
 130 }
 131 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
 132
 133 /*
 134  * Scheduling handlers
 135  */
 136
 137 /**
 138  * v4l2_m2m_get_curr_priv() - return driver private data for the currently
 139  * running instance or NULL if no instance is running
 140  */
 141 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
 142 {
 143         unsigned long flags;
 144         void *ret = NULL;
 145
 146         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 147         if (m2m_dev->curr_ctx)
 148                 ret = m2m_dev->curr_ctx->priv;
 149         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 150
 151         return ret;
 152 }
 153 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
 154
 155 /**
 156  * v4l2_m2m_try_run() - select next job to perform and run it if possible
 157  *
 158  * Get next transaction (if present) from the waiting jobs list and run it.
 159  */
 160 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
 161 {
 162         unsigned long flags;
 163
 164         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 165         if (NULL != m2m_dev->curr_ctx) {
 166                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 167                 dprintk("Another instance is running, won't run now\n");
 168                 return;
 169         }
 170
 171         if (list_empty(&m2m_dev->job_queue)) {
 172                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 173                 dprintk("No job pending\n");
 174                 return;
 175         }
 176
 177         m2m_dev->curr_ctx = list_entry(m2m_dev->job_queue.next,
 178                                    struct v4l2_m2m_ctx, queue);
 179         m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
 180         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 181
 182         m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
 183 }
 184
 185 /**
 186  * v4l2_m2m_try_schedule() - check whether an instance is ready to be added to
 187  * the pending job queue and add it if so.
 188  * @m2m_ctx:    m2m context assigned to the instance to be checked
 189  *
 190  * There are three basic requirements an instance has to meet to be able to run:
 191  * 1) at least one source buffer has to be queued,
 192  * 2) at least one destination buffer has to be queued,
 193  * 3) streaming has to be on.
 194  *
 195  * There may also be additional, custom requirements. In such case the driver
 196  * should supply a custom callback (job_ready in v4l2_m2m_ops) that should
 197  * return 1 if the instance is ready.
 198  * An example of the above could be an instance that requires more than one
 199  * src/dst buffer per transaction.
 200  */
 201 static void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
 202 {
 203         struct v4l2_m2m_dev *m2m_dev;
 204         unsigned long flags_job, flags;
 205
 206         m2m_dev = m2m_ctx->m2m_dev;
 207         dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
 208
 209         if (!m2m_ctx->out_q_ctx.q.streaming
 210             || !m2m_ctx->cap_q_ctx.q.streaming) {
 211                 dprintk("Streaming needs to be on for both queues\n");
 212                 return;
 213         }
 214
 215         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 216         if (m2m_ctx->job_flags & TRANS_QUEUED) {
 217                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 218                 dprintk("On job queue already\n");
 219                 return;
 220         }
 221
 222         spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 223         if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)) {
 224                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 225                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 226                 dprintk("No input buffers available\n");
 227                 return;
 228         }
 229         spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
 230         if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)) {
 231                 spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
 232                 spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 233                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 234                 dprintk("No output buffers available\n");
 235                 return;
 236         }
 237         spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags);
 238         spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags);
 239
 240         if (m2m_dev->m2m_ops->job_ready
 241                 && (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
 242                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 243                 dprintk("Driver not ready\n");
 244                 return;
 245         }
 246
 247         list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
 248         m2m_ctx->job_flags |= TRANS_QUEUED;
 249
 250         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 251
 252         v4l2_m2m_try_run(m2m_dev);
 253 }
 254
 255 /**
 256  * v4l2_m2m_job_finish() - inform the framework that a job has been finished
 257  * and have it clean up
 258  *
 259  * Called by a driver to yield back the device after it has finished with it.
 260  * Should be called as soon as possible after reaching a state which allows
 261  * other instances to take control of the device.
 262  *
 263  * This function has to be called only after device_run() callback has been
 264  * called on the driver. To prevent recursion, it should not be called directly
 265  * from the device_run() callback though.
 266  */
 267 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
 268                          struct v4l2_m2m_ctx *m2m_ctx)
 269 {
 270         unsigned long flags;
 271
 272         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 273         if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
 274                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 275                 dprintk("Called by an instance not currently running\n");
 276                 return;
 277         }
 278
 279         list_del(&m2m_dev->curr_ctx->queue);
 280         m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 281         wake_up(&m2m_dev->curr_ctx->finished);
 282         m2m_dev->curr_ctx = NULL;
 283
 284         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 285
 286         /* This instance might have more buffers ready, but since we do not
 287          * allow more than one job on the job_queue per instance, each has
 288          * to be scheduled separately after the previous one finishes. */
 289         v4l2_m2m_try_schedule(m2m_ctx);
 290         v4l2_m2m_try_run(m2m_dev);
 291 }
 292 EXPORT_SYMBOL(v4l2_m2m_job_finish);
 293
 294 /**
 295  * v4l2_m2m_reqbufs() - multi-queue-aware REQBUFS multiplexer
 296  */
 297 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 298                      struct v4l2_requestbuffers *reqbufs)
 299 {
 300         struct vb2_queue *vq;
 301
 302         vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
 303         return vb2_reqbufs(vq, reqbufs);
 304 }
 305 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
 306
 307 /**
 308  * v4l2_m2m_querybuf() - multi-queue-aware QUERYBUF multiplexer
 309  *
 310  * See v4l2_m2m_mmap() documentation for details.
 311  */
 312 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 313                       struct v4l2_buffer *buf)
 314 {
 315         struct vb2_queue *vq;
 316         int ret = 0;
 317         unsigned int i;
 318
 319         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 320         ret = vb2_querybuf(vq, buf);
 321
 322         /* Adjust MMAP memory offsets for the CAPTURE queue */
 323         if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
 324                 if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
 325                         for (i = 0; i < buf->length; ++i)
 326                                 buf->m.planes[i].m.mem_offset
 327                                         += DST_QUEUE_OFF_BASE;
 328                 } else {
 329                         buf->m.offset += DST_QUEUE_OFF_BASE;
 330                 }
 331         }
 332
 333         return ret;
 334 }
 335 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
 336 /*
 337  * v4l2_m2m_expbuf() - multi-queue-not-aware EXPBUF
 338  */
 339 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 340                                                 struct v4l2_exportbuffer *eb)
 341 {
 342         struct vb2_queue *vq;
 343         if (eb->mem_offset < DST_QUEUE_OFF_BASE) {
 344                 vq = v4l2_m2m_get_vq(m2m_ctx, V4L2_BUF_TYPE_VIDEO_OUTPUT);
 345         } else {
 346                 vq = v4l2_m2m_get_vq(m2m_ctx, V4L2_BUF_TYPE_VIDEO_CAPTURE);
 347                 eb->mem_offset -= DST_QUEUE_OFF_BASE;
 348         }
 349         return vb2_expbuf(vq, eb);
 350 }
 351 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
 352
 353 /**
 354  * v4l2_m2m_qbuf() - enqueue a source or destination buffer, depending on
 355  * the type
 356  */
 357 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 358                   struct v4l2_buffer *buf)
 359 {
 360         struct vb2_queue *vq;
 361         int ret;
 362
 363         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 364         ret = vb2_qbuf(vq, buf);
 365         if (!ret)
 366                 v4l2_m2m_try_schedule(m2m_ctx);
 367
 368         return ret;
 369 }
 370 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
 371
 372 /**
 373  * v4l2_m2m_dqbuf() - dequeue a source or destination buffer, depending on
 374  * the type
 375  */
 376 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 377                    struct v4l2_buffer *buf)
 378 {
 379         struct vb2_queue *vq;
 380
 381         vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
 382         return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
 383 }
 384 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
 385
 386 /**
 387  * v4l2_m2m_streamon() - turn on streaming for a video queue
 388  */
 389 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 390                       enum v4l2_buf_type type)
 391 {
 392         struct vb2_queue *vq;
 393         int ret;
 394
 395         vq = v4l2_m2m_get_vq(m2m_ctx, type);
 396         ret = vb2_streamon(vq, type);
 397         if (!ret)
 398                 v4l2_m2m_try_schedule(m2m_ctx);
 399
 400         return ret;
 401 }
 402 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
 403
 404 /**
 405  * v4l2_m2m_streamoff() - turn off streaming for a video queue
 406  */
 407 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 408                        enum v4l2_buf_type type)
 409 {
 410         struct v4l2_m2m_dev *m2m_dev;
 411         struct v4l2_m2m_queue_ctx *q_ctx;
 412         unsigned long flags_job, flags;
 413         int ret;
 414
 415         q_ctx = get_queue_ctx(m2m_ctx, type);
 416         ret = vb2_streamoff(&q_ctx->q, type);
 417         if (ret)
 418                 return ret;
 419
 420         m2m_dev = m2m_ctx->m2m_dev;
 421         spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
 422         /* We should not be scheduled anymore, since we're dropping a queue. */
 423         INIT_LIST_HEAD(&m2m_ctx->queue);
 424         m2m_ctx->job_flags = 0;
 425
 426         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 427         /* Drop queue, since streamoff returns device to the same state as after
 428          * calling reqbufs. */
 429         INIT_LIST_HEAD(&q_ctx->rdy_queue);
 430         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 431
 432         if (m2m_dev->curr_ctx == m2m_ctx) {
 433                 m2m_dev->curr_ctx = NULL;
 434                 wake_up(&m2m_ctx->finished);
 435         }
 436         spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
 437
 438         return 0;
 439 }
 440 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
 441
 442 /**
 443  * v4l2_m2m_poll() - poll replacement, for destination buffers only
 444  *
 445  * Call from the driver's poll() function. Will poll both queues. If a buffer
 446  * is available to dequeue (with dqbuf) from the source queue, this will
 447  * indicate that a non-blocking write can be performed, while read will be
 448  * returned in case of the destination queue.
 449  */
 450 unsigned int v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 451                            struct poll_table_struct *wait)
 452 {
 453         struct vb2_queue *src_q, *dst_q;
 454         struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
 455         unsigned int rc = 0;
 456         unsigned long flags;
 457
 458         src_q = v4l2_m2m_get_src_vq(m2m_ctx);
 459         dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
 460
 461         /*
 462          * There has to be at least one buffer queued on each queued_list, which
 463          * means either in driver already or waiting for driver to claim it
 464          * and start processing.
 465          */
 466         if ((!src_q->streaming || list_empty(&src_q->queued_list))
 467                 && (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
 468                 rc = POLLERR;
 469                 goto end;
 470         }
 471
 472         if (m2m_ctx->m2m_dev->m2m_ops->unlock)
 473                 m2m_ctx->m2m_dev->m2m_ops->unlock(m2m_ctx->priv);
 474
 475         poll_wait(file, &src_q->done_wq, wait);
 476         poll_wait(file, &dst_q->done_wq, wait);
 477
 478         if (m2m_ctx->m2m_dev->m2m_ops->lock)
 479                 m2m_ctx->m2m_dev->m2m_ops->lock(m2m_ctx->priv);
 480
 481         spin_lock_irqsave(&src_q->done_lock, flags);
 482         if (!list_empty(&src_q->done_list))
 483                 src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
 484                                                 done_entry);
 485         if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
 486                         || src_vb->state == VB2_BUF_STATE_ERROR))
 487                 rc |= POLLOUT | POLLWRNORM;
 488         spin_unlock_irqrestore(&src_q->done_lock, flags);
 489
 490         spin_lock_irqsave(&dst_q->done_lock, flags);
 491         if (!list_empty(&dst_q->done_list))
 492                 dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
 493                                                 done_entry);
 494         if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
 495                         || dst_vb->state == VB2_BUF_STATE_ERROR))
 496                 rc |= POLLIN | POLLRDNORM;
 497         spin_unlock_irqrestore(&dst_q->done_lock, flags);
 498
 499 end:
 500         return rc;
 501 }
 502 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
 503
 504 /**
 505  * v4l2_m2m_mmap() - source and destination queues-aware mmap multiplexer
 506  *
 507  * Call from driver's mmap() function. Will handle mmap() for both queues
 508  * seamlessly for videobuffer, which will receive normal per-queue offsets and
 509  * proper videobuf queue pointers. The differentiation is made outside videobuf
 510  * by adding a predefined offset to buffers from one of the queues and
 511  * subtracting it before passing it back to videobuf. Only drivers (and
 512  * thus applications) receive modified offsets.
 513  */
 514 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
 515                          struct vm_area_struct *vma)
 516 {
 517         unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
 518         struct vb2_queue *vq;
 519
 520         if (offset < DST_QUEUE_OFF_BASE) {
 521                 vq = v4l2_m2m_get_src_vq(m2m_ctx);
 522         } else {
 523                 vq = v4l2_m2m_get_dst_vq(m2m_ctx);
 524                 vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
 525         }
 526
 527         return vb2_mmap(vq, vma);
 528 }
 529 EXPORT_SYMBOL(v4l2_m2m_mmap);
 530
 531 /**
 532  * v4l2_m2m_init() - initialize per-driver m2m data
 533  *
 534  * Usually called from driver's probe() function.
 535  */
 536 struct v4l2_m2m_dev *v4l2_m2m_init(struct v4l2_m2m_ops *m2m_ops)
 537 {
 538         struct v4l2_m2m_dev *m2m_dev;
 539
 540         if (!m2m_ops)
 541                 return ERR_PTR(-EINVAL);
 542
 543         BUG_ON(!m2m_ops->device_run);
 544         BUG_ON(!m2m_ops->job_abort);
 545
 546         m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
 547         if (!m2m_dev)
 548                 return ERR_PTR(-ENOMEM);
 549
 550         m2m_dev->curr_ctx = NULL;
 551         m2m_dev->m2m_ops = m2m_ops;
 552         INIT_LIST_HEAD(&m2m_dev->job_queue);
 553         spin_lock_init(&m2m_dev->job_spinlock);
 554
 555         return m2m_dev;
 556 }
 557 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
 558
 559 /**
 560  * v4l2_m2m_release() - cleans up and frees a m2m_dev structure
 561  *
 562  * Usually called from driver's remove() function.
 563  */
 564 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
 565 {
 566         kfree(m2m_dev);
 567 }
 568 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
 569
 570 /**
 571  * v4l2_m2m_ctx_init() - allocate and initialize a m2m context
 572  * @priv - driver's instance private data
 573  * @m2m_dev - a previously initialized m2m_dev struct
 574  * @vq_init - a callback for queue type-specific initialization function to be
 575  * used for initializing videobuf_queues
 576  *
 577  * Usually called from driver's open() function.
 578  */
 579 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
 580                 void *drv_priv,
 581                 int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
 582 {
 583         struct v4l2_m2m_ctx *m2m_ctx;
 584         struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
 585         int ret;
 586
 587         m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
 588         if (!m2m_ctx)
 589                 return ERR_PTR(-ENOMEM);
 590
 591         m2m_ctx->priv = drv_priv;
 592         m2m_ctx->m2m_dev = m2m_dev;
 593         init_waitqueue_head(&m2m_ctx->finished);
 594
 595         out_q_ctx = &m2m_ctx->out_q_ctx;
 596         cap_q_ctx = &m2m_ctx->cap_q_ctx;
 597
 598         INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
 599         INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
 600         spin_lock_init(&out_q_ctx->rdy_spinlock);
 601         spin_lock_init(&cap_q_ctx->rdy_spinlock);
 602
 603         INIT_LIST_HEAD(&m2m_ctx->queue);
 604
 605         ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
 606
 607         if (ret)
 608                 goto err;
 609
 610         return m2m_ctx;
 611 err:
 612         kfree(m2m_ctx);
 613         return ERR_PTR(ret);
 614 }
 615 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
 616
 617 /**
 618  * v4l2_m2m_ctx_release() - release m2m context
 619  *
 620  * Usually called from driver's release() function.
 621  */
 622 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
 623 {
 624         struct v4l2_m2m_dev *m2m_dev;
 625         unsigned long flags;
 626
 627         m2m_dev = m2m_ctx->m2m_dev;
 628
 629         spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
 630         if (m2m_ctx->job_flags & TRANS_RUNNING) {
 631                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 632                 m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
 633                 dprintk("m2m_ctx %p running, will wait to complete", m2m_ctx);
 634                 wait_event(m2m_ctx->finished, !(m2m_ctx->job_flags & TRANS_RUNNING));
 635         } else if (m2m_ctx->job_flags & TRANS_QUEUED) {
 636                 list_del(&m2m_ctx->queue);
 637                 m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
 638                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 639                 dprintk("m2m_ctx: %p had been on queue and was removed\n",
 640                         m2m_ctx);
 641         } else {
 642                 /* Do nothing, was not on queue/running */
 643                 spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
 644         }
 645
 646         vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
 647         vb2_queue_release(&m2m_ctx->out_q_ctx.q);
 648
 649         kfree(m2m_ctx);
 650 }
 651 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
 652
 653 /**
 654  * v4l2_m2m_buf_queue() - add a buffer to the proper ready buffers list.
 655  *
 656  * Call from buf_queue(), videobuf_queue_ops callback.
 657  */
 658 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx, struct vb2_buffer *vb)
 659 {
 660         struct v4l2_m2m_buffer *b = container_of(vb, struct v4l2_m2m_buffer, vb);
 661         struct v4l2_m2m_queue_ctx *q_ctx;
 662         unsigned long flags;
 663
 664         q_ctx = get_queue_ctx(m2m_ctx, vb->vb2_queue->type);
 665         if (!q_ctx)
 666                 return;
 667
 668         spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
 669         list_add_tail(&b->list, &q_ctx->rdy_queue);
 670         q_ctx->num_rdy++;
 671         spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
 672 }
 673 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
 674