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/media-device.h>
21 #include <media/videobuf2-v4l2.h>
22 #include <media/v4l2-mem2mem.h>
23 #include <media/v4l2-dev.h>
24 #include <media/v4l2-device.h>
25 #include <media/v4l2-fh.h>
26 #include <media/v4l2-event.h>
27 
28 MODULE_DESCRIPTION("Mem to mem device framework for videobuf");
29 MODULE_AUTHOR("Pawel Osciak, <pawel@osciak.com>");
30 MODULE_LICENSE("GPL");
31 
32 static bool debug;
33 module_param(debug, bool, 0644);
34 
35 #define dprintk(fmt, arg...)						\
36 	do {								\
37 		if (debug)						\
38 			printk(KERN_DEBUG "%s: " fmt, __func__, ## arg);\
39 	} while (0)
40 
41 
42 /* Instance is already queued on the job_queue */
43 #define TRANS_QUEUED		(1 << 0)
44 /* Instance is currently running in hardware */
45 #define TRANS_RUNNING		(1 << 1)
46 /* Instance is currently aborting */
47 #define TRANS_ABORT		(1 << 2)
48 
49 
50 /* Offset base for buffers on the destination queue - used to distinguish
51  * between source and destination buffers when mmapping - they receive the same
52  * offsets but for different queues */
53 #define DST_QUEUE_OFF_BASE	(1 << 30)
54 
55 enum v4l2_m2m_entity_type {
56 	MEM2MEM_ENT_TYPE_SOURCE,
57 	MEM2MEM_ENT_TYPE_SINK,
58 	MEM2MEM_ENT_TYPE_PROC
59 };
60 
61 static const char * const m2m_entity_name[] = {
62 	"source",
63 	"sink",
64 	"proc"
65 };
66 
67 /**
68  * struct v4l2_m2m_dev - per-device context
69  * @source:		&struct media_entity pointer with the source entity
70  *			Used only when the M2M device is registered via
71  *			v4l2_m2m_unregister_media_controller().
72  * @source_pad:		&struct media_pad with the source pad.
73  *			Used only when the M2M device is registered via
74  *			v4l2_m2m_unregister_media_controller().
75  * @sink:		&struct media_entity pointer with the sink entity
76  *			Used only when the M2M device is registered via
77  *			v4l2_m2m_unregister_media_controller().
78  * @sink_pad:		&struct media_pad with the sink pad.
79  *			Used only when the M2M device is registered via
80  *			v4l2_m2m_unregister_media_controller().
81  * @proc:		&struct media_entity pointer with the M2M device itself.
82  * @proc_pads:		&struct media_pad with the @proc pads.
83  *			Used only when the M2M device is registered via
84  *			v4l2_m2m_unregister_media_controller().
85  * @intf_devnode:	&struct media_intf devnode pointer with the interface
86  *			with controls the M2M device.
87  * @curr_ctx:		currently running instance
88  * @job_queue:		instances queued to run
89  * @job_spinlock:	protects job_queue
90  * @job_work:		worker to run queued jobs.
91  * @m2m_ops:		driver callbacks
92  */
93 struct v4l2_m2m_dev {
94 	struct v4l2_m2m_ctx	*curr_ctx;
95 #ifdef CONFIG_MEDIA_CONTROLLER
96 	struct media_entity	*source;
97 	struct media_pad	source_pad;
98 	struct media_entity	sink;
99 	struct media_pad	sink_pad;
100 	struct media_entity	proc;
101 	struct media_pad	proc_pads[2];
102 	struct media_intf_devnode *intf_devnode;
103 #endif
104 
105 	struct list_head	job_queue;
106 	spinlock_t		job_spinlock;
107 	struct work_struct	job_work;
108 
109 	const struct v4l2_m2m_ops *m2m_ops;
110 };
111 
112 static struct v4l2_m2m_queue_ctx *get_queue_ctx(struct v4l2_m2m_ctx *m2m_ctx,
113 						enum v4l2_buf_type type)
114 {
115 	if (V4L2_TYPE_IS_OUTPUT(type))
116 		return &m2m_ctx->out_q_ctx;
117 	else
118 		return &m2m_ctx->cap_q_ctx;
119 }
120 
121 struct vb2_queue *v4l2_m2m_get_vq(struct v4l2_m2m_ctx *m2m_ctx,
122 				       enum v4l2_buf_type type)
123 {
124 	struct v4l2_m2m_queue_ctx *q_ctx;
125 
126 	q_ctx = get_queue_ctx(m2m_ctx, type);
127 	if (!q_ctx)
128 		return NULL;
129 
130 	return &q_ctx->q;
131 }
132 EXPORT_SYMBOL(v4l2_m2m_get_vq);
133 
134 void *v4l2_m2m_next_buf(struct v4l2_m2m_queue_ctx *q_ctx)
135 {
136 	struct v4l2_m2m_buffer *b;
137 	unsigned long flags;
138 
139 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
140 
141 	if (list_empty(&q_ctx->rdy_queue)) {
142 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
143 		return NULL;
144 	}
145 
146 	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
147 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
148 	return &b->vb;
149 }
150 EXPORT_SYMBOL_GPL(v4l2_m2m_next_buf);
151 
152 void *v4l2_m2m_last_buf(struct v4l2_m2m_queue_ctx *q_ctx)
153 {
154 	struct v4l2_m2m_buffer *b;
155 	unsigned long flags;
156 
157 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
158 
159 	if (list_empty(&q_ctx->rdy_queue)) {
160 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
161 		return NULL;
162 	}
163 
164 	b = list_last_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
165 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
166 	return &b->vb;
167 }
168 EXPORT_SYMBOL_GPL(v4l2_m2m_last_buf);
169 
170 void *v4l2_m2m_buf_remove(struct v4l2_m2m_queue_ctx *q_ctx)
171 {
172 	struct v4l2_m2m_buffer *b;
173 	unsigned long flags;
174 
175 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
176 	if (list_empty(&q_ctx->rdy_queue)) {
177 		spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
178 		return NULL;
179 	}
180 	b = list_first_entry(&q_ctx->rdy_queue, struct v4l2_m2m_buffer, list);
181 	list_del(&b->list);
182 	q_ctx->num_rdy--;
183 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
184 
185 	return &b->vb;
186 }
187 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove);
188 
189 void v4l2_m2m_buf_remove_by_buf(struct v4l2_m2m_queue_ctx *q_ctx,
190 				struct vb2_v4l2_buffer *vbuf)
191 {
192 	struct v4l2_m2m_buffer *b;
193 	unsigned long flags;
194 
195 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
196 	b = container_of(vbuf, struct v4l2_m2m_buffer, vb);
197 	list_del(&b->list);
198 	q_ctx->num_rdy--;
199 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
200 }
201 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_buf);
202 
203 struct vb2_v4l2_buffer *
204 v4l2_m2m_buf_remove_by_idx(struct v4l2_m2m_queue_ctx *q_ctx, unsigned int idx)
205 
206 {
207 	struct v4l2_m2m_buffer *b, *tmp;
208 	struct vb2_v4l2_buffer *ret = NULL;
209 	unsigned long flags;
210 
211 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
212 	list_for_each_entry_safe(b, tmp, &q_ctx->rdy_queue, list) {
213 		if (b->vb.vb2_buf.index == idx) {
214 			list_del(&b->list);
215 			q_ctx->num_rdy--;
216 			ret = &b->vb;
217 			break;
218 		}
219 	}
220 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
221 
222 	return ret;
223 }
224 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_remove_by_idx);
225 
226 /*
227  * Scheduling handlers
228  */
229 
230 void *v4l2_m2m_get_curr_priv(struct v4l2_m2m_dev *m2m_dev)
231 {
232 	unsigned long flags;
233 	void *ret = NULL;
234 
235 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
236 	if (m2m_dev->curr_ctx)
237 		ret = m2m_dev->curr_ctx->priv;
238 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
239 
240 	return ret;
241 }
242 EXPORT_SYMBOL(v4l2_m2m_get_curr_priv);
243 
244 /**
245  * v4l2_m2m_try_run() - select next job to perform and run it if possible
246  * @m2m_dev: per-device context
247  *
248  * Get next transaction (if present) from the waiting jobs list and run it.
249  *
250  * Note that this function can run on a given v4l2_m2m_ctx context,
251  * but call .device_run for another context.
252  */
253 static void v4l2_m2m_try_run(struct v4l2_m2m_dev *m2m_dev)
254 {
255 	unsigned long flags;
256 
257 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
258 	if (NULL != m2m_dev->curr_ctx) {
259 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
260 		dprintk("Another instance is running, won't run now\n");
261 		return;
262 	}
263 
264 	if (list_empty(&m2m_dev->job_queue)) {
265 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
266 		dprintk("No job pending\n");
267 		return;
268 	}
269 
270 	m2m_dev->curr_ctx = list_first_entry(&m2m_dev->job_queue,
271 				   struct v4l2_m2m_ctx, queue);
272 	m2m_dev->curr_ctx->job_flags |= TRANS_RUNNING;
273 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
274 
275 	dprintk("Running job on m2m_ctx: %p\n", m2m_dev->curr_ctx);
276 	m2m_dev->m2m_ops->device_run(m2m_dev->curr_ctx->priv);
277 }
278 
279 /*
280  * __v4l2_m2m_try_queue() - queue a job
281  * @m2m_dev: m2m device
282  * @m2m_ctx: m2m context
283  *
284  * Check if this context is ready to queue a job.
285  *
286  * This function can run in interrupt context.
287  */
288 static void __v4l2_m2m_try_queue(struct v4l2_m2m_dev *m2m_dev,
289 				 struct v4l2_m2m_ctx *m2m_ctx)
290 {
291 	unsigned long flags_job, flags_out, flags_cap;
292 
293 	dprintk("Trying to schedule a job for m2m_ctx: %p\n", m2m_ctx);
294 
295 	if (!m2m_ctx->out_q_ctx.q.streaming
296 	    || !m2m_ctx->cap_q_ctx.q.streaming) {
297 		dprintk("Streaming needs to be on for both queues\n");
298 		return;
299 	}
300 
301 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
302 
303 	/* If the context is aborted then don't schedule it */
304 	if (m2m_ctx->job_flags & TRANS_ABORT) {
305 		dprintk("Aborted context\n");
306 		goto job_unlock;
307 	}
308 
309 	if (m2m_ctx->job_flags & TRANS_QUEUED) {
310 		dprintk("On job queue already\n");
311 		goto job_unlock;
312 	}
313 
314 	spin_lock_irqsave(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
315 	if (list_empty(&m2m_ctx->out_q_ctx.rdy_queue)
316 	    && !m2m_ctx->out_q_ctx.buffered) {
317 		dprintk("No input buffers available\n");
318 		goto out_unlock;
319 	}
320 	spin_lock_irqsave(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
321 	if (list_empty(&m2m_ctx->cap_q_ctx.rdy_queue)
322 	    && !m2m_ctx->cap_q_ctx.buffered) {
323 		dprintk("No output buffers available\n");
324 		goto cap_unlock;
325 	}
326 	spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
327 	spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
328 
329 	if (m2m_dev->m2m_ops->job_ready
330 		&& (!m2m_dev->m2m_ops->job_ready(m2m_ctx->priv))) {
331 		dprintk("Driver not ready\n");
332 		goto job_unlock;
333 	}
334 
335 	list_add_tail(&m2m_ctx->queue, &m2m_dev->job_queue);
336 	m2m_ctx->job_flags |= TRANS_QUEUED;
337 
338 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
339 	return;
340 
341 cap_unlock:
342 	spin_unlock_irqrestore(&m2m_ctx->cap_q_ctx.rdy_spinlock, flags_cap);
343 out_unlock:
344 	spin_unlock_irqrestore(&m2m_ctx->out_q_ctx.rdy_spinlock, flags_out);
345 job_unlock:
346 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
347 }
348 
349 /**
350  * v4l2_m2m_try_schedule() - schedule and possibly run a job for any context
351  * @m2m_ctx: m2m context
352  *
353  * Check if this context is ready to queue a job. If suitable,
354  * run the next queued job on the mem2mem device.
355  *
356  * This function shouldn't run in interrupt context.
357  *
358  * Note that v4l2_m2m_try_schedule() can schedule one job for this context,
359  * and then run another job for another context.
360  */
361 void v4l2_m2m_try_schedule(struct v4l2_m2m_ctx *m2m_ctx)
362 {
363 	struct v4l2_m2m_dev *m2m_dev = m2m_ctx->m2m_dev;
364 
365 	__v4l2_m2m_try_queue(m2m_dev, m2m_ctx);
366 	v4l2_m2m_try_run(m2m_dev);
367 }
368 EXPORT_SYMBOL_GPL(v4l2_m2m_try_schedule);
369 
370 /**
371  * v4l2_m2m_device_run_work() - run pending jobs for the context
372  * @work: Work structure used for scheduling the execution of this function.
373  */
374 static void v4l2_m2m_device_run_work(struct work_struct *work)
375 {
376 	struct v4l2_m2m_dev *m2m_dev =
377 		container_of(work, struct v4l2_m2m_dev, job_work);
378 
379 	v4l2_m2m_try_run(m2m_dev);
380 }
381 
382 /**
383  * v4l2_m2m_cancel_job() - cancel pending jobs for the context
384  * @m2m_ctx: m2m context with jobs to be canceled
385  *
386  * In case of streamoff or release called on any context,
387  * 1] If the context is currently running, then abort job will be called
388  * 2] If the context is queued, then the context will be removed from
389  *    the job_queue
390  */
391 static void v4l2_m2m_cancel_job(struct v4l2_m2m_ctx *m2m_ctx)
392 {
393 	struct v4l2_m2m_dev *m2m_dev;
394 	unsigned long flags;
395 
396 	m2m_dev = m2m_ctx->m2m_dev;
397 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
398 
399 	m2m_ctx->job_flags |= TRANS_ABORT;
400 	if (m2m_ctx->job_flags & TRANS_RUNNING) {
401 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
402 		if (m2m_dev->m2m_ops->job_abort)
403 			m2m_dev->m2m_ops->job_abort(m2m_ctx->priv);
404 		dprintk("m2m_ctx %p running, will wait to complete\n", m2m_ctx);
405 		wait_event(m2m_ctx->finished,
406 				!(m2m_ctx->job_flags & TRANS_RUNNING));
407 	} else if (m2m_ctx->job_flags & TRANS_QUEUED) {
408 		list_del(&m2m_ctx->queue);
409 		m2m_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
410 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
411 		dprintk("m2m_ctx: %p had been on queue and was removed\n",
412 			m2m_ctx);
413 	} else {
414 		/* Do nothing, was not on queue/running */
415 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
416 	}
417 }
418 
419 void v4l2_m2m_job_finish(struct v4l2_m2m_dev *m2m_dev,
420 			 struct v4l2_m2m_ctx *m2m_ctx)
421 {
422 	unsigned long flags;
423 
424 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags);
425 	if (!m2m_dev->curr_ctx || m2m_dev->curr_ctx != m2m_ctx) {
426 		spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
427 		dprintk("Called by an instance not currently running\n");
428 		return;
429 	}
430 
431 	list_del(&m2m_dev->curr_ctx->queue);
432 	m2m_dev->curr_ctx->job_flags &= ~(TRANS_QUEUED | TRANS_RUNNING);
433 	wake_up(&m2m_dev->curr_ctx->finished);
434 	m2m_dev->curr_ctx = NULL;
435 
436 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags);
437 
438 	/* This instance might have more buffers ready, but since we do not
439 	 * allow more than one job on the job_queue per instance, each has
440 	 * to be scheduled separately after the previous one finishes. */
441 	__v4l2_m2m_try_queue(m2m_dev, m2m_ctx);
442 
443 	/* We might be running in atomic context,
444 	 * but the job must be run in non-atomic context.
445 	 */
446 	schedule_work(&m2m_dev->job_work);
447 }
448 EXPORT_SYMBOL(v4l2_m2m_job_finish);
449 
450 int v4l2_m2m_reqbufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
451 		     struct v4l2_requestbuffers *reqbufs)
452 {
453 	struct vb2_queue *vq;
454 	int ret;
455 
456 	vq = v4l2_m2m_get_vq(m2m_ctx, reqbufs->type);
457 	ret = vb2_reqbufs(vq, reqbufs);
458 	/* If count == 0, then the owner has released all buffers and he
459 	   is no longer owner of the queue. Otherwise we have an owner. */
460 	if (ret == 0)
461 		vq->owner = reqbufs->count ? file->private_data : NULL;
462 
463 	return ret;
464 }
465 EXPORT_SYMBOL_GPL(v4l2_m2m_reqbufs);
466 
467 int v4l2_m2m_querybuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
468 		      struct v4l2_buffer *buf)
469 {
470 	struct vb2_queue *vq;
471 	int ret = 0;
472 	unsigned int i;
473 
474 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
475 	ret = vb2_querybuf(vq, buf);
476 
477 	/* Adjust MMAP memory offsets for the CAPTURE queue */
478 	if (buf->memory == V4L2_MEMORY_MMAP && !V4L2_TYPE_IS_OUTPUT(vq->type)) {
479 		if (V4L2_TYPE_IS_MULTIPLANAR(vq->type)) {
480 			for (i = 0; i < buf->length; ++i)
481 				buf->m.planes[i].m.mem_offset
482 					+= DST_QUEUE_OFF_BASE;
483 		} else {
484 			buf->m.offset += DST_QUEUE_OFF_BASE;
485 		}
486 	}
487 
488 	return ret;
489 }
490 EXPORT_SYMBOL_GPL(v4l2_m2m_querybuf);
491 
492 int v4l2_m2m_qbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
493 		  struct v4l2_buffer *buf)
494 {
495 	struct video_device *vdev = video_devdata(file);
496 	struct vb2_queue *vq;
497 	int ret;
498 
499 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
500 	if (!V4L2_TYPE_IS_OUTPUT(vq->type) &&
501 	    (buf->flags & V4L2_BUF_FLAG_REQUEST_FD)) {
502 		dprintk("%s: requests cannot be used with capture buffers\n",
503 			__func__);
504 		return -EPERM;
505 	}
506 	ret = vb2_qbuf(vq, vdev->v4l2_dev->mdev, buf);
507 	if (!ret && !(buf->flags & V4L2_BUF_FLAG_IN_REQUEST))
508 		v4l2_m2m_try_schedule(m2m_ctx);
509 
510 	return ret;
511 }
512 EXPORT_SYMBOL_GPL(v4l2_m2m_qbuf);
513 
514 int v4l2_m2m_dqbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
515 		   struct v4l2_buffer *buf)
516 {
517 	struct vb2_queue *vq;
518 
519 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
520 	return vb2_dqbuf(vq, buf, file->f_flags & O_NONBLOCK);
521 }
522 EXPORT_SYMBOL_GPL(v4l2_m2m_dqbuf);
523 
524 int v4l2_m2m_prepare_buf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
525 			 struct v4l2_buffer *buf)
526 {
527 	struct video_device *vdev = video_devdata(file);
528 	struct vb2_queue *vq;
529 
530 	vq = v4l2_m2m_get_vq(m2m_ctx, buf->type);
531 	return vb2_prepare_buf(vq, vdev->v4l2_dev->mdev, buf);
532 }
533 EXPORT_SYMBOL_GPL(v4l2_m2m_prepare_buf);
534 
535 int v4l2_m2m_create_bufs(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
536 			 struct v4l2_create_buffers *create)
537 {
538 	struct vb2_queue *vq;
539 
540 	vq = v4l2_m2m_get_vq(m2m_ctx, create->format.type);
541 	return vb2_create_bufs(vq, create);
542 }
543 EXPORT_SYMBOL_GPL(v4l2_m2m_create_bufs);
544 
545 int v4l2_m2m_expbuf(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
546 		  struct v4l2_exportbuffer *eb)
547 {
548 	struct vb2_queue *vq;
549 
550 	vq = v4l2_m2m_get_vq(m2m_ctx, eb->type);
551 	return vb2_expbuf(vq, eb);
552 }
553 EXPORT_SYMBOL_GPL(v4l2_m2m_expbuf);
554 
555 int v4l2_m2m_streamon(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
556 		      enum v4l2_buf_type type)
557 {
558 	struct vb2_queue *vq;
559 	int ret;
560 
561 	vq = v4l2_m2m_get_vq(m2m_ctx, type);
562 	ret = vb2_streamon(vq, type);
563 	if (!ret)
564 		v4l2_m2m_try_schedule(m2m_ctx);
565 
566 	return ret;
567 }
568 EXPORT_SYMBOL_GPL(v4l2_m2m_streamon);
569 
570 int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
571 		       enum v4l2_buf_type type)
572 {
573 	struct v4l2_m2m_dev *m2m_dev;
574 	struct v4l2_m2m_queue_ctx *q_ctx;
575 	unsigned long flags_job, flags;
576 	int ret;
577 
578 	/* wait until the current context is dequeued from job_queue */
579 	v4l2_m2m_cancel_job(m2m_ctx);
580 
581 	q_ctx = get_queue_ctx(m2m_ctx, type);
582 	ret = vb2_streamoff(&q_ctx->q, type);
583 	if (ret)
584 		return ret;
585 
586 	m2m_dev = m2m_ctx->m2m_dev;
587 	spin_lock_irqsave(&m2m_dev->job_spinlock, flags_job);
588 	/* We should not be scheduled anymore, since we're dropping a queue. */
589 	if (m2m_ctx->job_flags & TRANS_QUEUED)
590 		list_del(&m2m_ctx->queue);
591 	m2m_ctx->job_flags = 0;
592 
593 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
594 	/* Drop queue, since streamoff returns device to the same state as after
595 	 * calling reqbufs. */
596 	INIT_LIST_HEAD(&q_ctx->rdy_queue);
597 	q_ctx->num_rdy = 0;
598 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
599 
600 	if (m2m_dev->curr_ctx == m2m_ctx) {
601 		m2m_dev->curr_ctx = NULL;
602 		wake_up(&m2m_ctx->finished);
603 	}
604 	spin_unlock_irqrestore(&m2m_dev->job_spinlock, flags_job);
605 
606 	return 0;
607 }
608 EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff);
609 
610 __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
611 			   struct poll_table_struct *wait)
612 {
613 	struct video_device *vfd = video_devdata(file);
614 	__poll_t req_events = poll_requested_events(wait);
615 	struct vb2_queue *src_q, *dst_q;
616 	struct vb2_buffer *src_vb = NULL, *dst_vb = NULL;
617 	__poll_t rc = 0;
618 	unsigned long flags;
619 
620 	if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) {
621 		struct v4l2_fh *fh = file->private_data;
622 
623 		if (v4l2_event_pending(fh))
624 			rc = EPOLLPRI;
625 		else if (req_events & EPOLLPRI)
626 			poll_wait(file, &fh->wait, wait);
627 		if (!(req_events & (EPOLLOUT | EPOLLWRNORM | EPOLLIN | EPOLLRDNORM)))
628 			return rc;
629 	}
630 
631 	src_q = v4l2_m2m_get_src_vq(m2m_ctx);
632 	dst_q = v4l2_m2m_get_dst_vq(m2m_ctx);
633 
634 	/*
635 	 * There has to be at least one buffer queued on each queued_list, which
636 	 * means either in driver already or waiting for driver to claim it
637 	 * and start processing.
638 	 */
639 	if ((!src_q->streaming || list_empty(&src_q->queued_list))
640 		&& (!dst_q->streaming || list_empty(&dst_q->queued_list))) {
641 		rc |= EPOLLERR;
642 		goto end;
643 	}
644 
645 	spin_lock_irqsave(&src_q->done_lock, flags);
646 	if (list_empty(&src_q->done_list))
647 		poll_wait(file, &src_q->done_wq, wait);
648 	spin_unlock_irqrestore(&src_q->done_lock, flags);
649 
650 	spin_lock_irqsave(&dst_q->done_lock, flags);
651 	if (list_empty(&dst_q->done_list)) {
652 		/*
653 		 * If the last buffer was dequeued from the capture queue,
654 		 * return immediately. DQBUF will return -EPIPE.
655 		 */
656 		if (dst_q->last_buffer_dequeued) {
657 			spin_unlock_irqrestore(&dst_q->done_lock, flags);
658 			return rc | EPOLLIN | EPOLLRDNORM;
659 		}
660 
661 		poll_wait(file, &dst_q->done_wq, wait);
662 	}
663 	spin_unlock_irqrestore(&dst_q->done_lock, flags);
664 
665 	spin_lock_irqsave(&src_q->done_lock, flags);
666 	if (!list_empty(&src_q->done_list))
667 		src_vb = list_first_entry(&src_q->done_list, struct vb2_buffer,
668 						done_entry);
669 	if (src_vb && (src_vb->state == VB2_BUF_STATE_DONE
670 			|| src_vb->state == VB2_BUF_STATE_ERROR))
671 		rc |= EPOLLOUT | EPOLLWRNORM;
672 	spin_unlock_irqrestore(&src_q->done_lock, flags);
673 
674 	spin_lock_irqsave(&dst_q->done_lock, flags);
675 	if (!list_empty(&dst_q->done_list))
676 		dst_vb = list_first_entry(&dst_q->done_list, struct vb2_buffer,
677 						done_entry);
678 	if (dst_vb && (dst_vb->state == VB2_BUF_STATE_DONE
679 			|| dst_vb->state == VB2_BUF_STATE_ERROR))
680 		rc |= EPOLLIN | EPOLLRDNORM;
681 	spin_unlock_irqrestore(&dst_q->done_lock, flags);
682 
683 end:
684 	return rc;
685 }
686 EXPORT_SYMBOL_GPL(v4l2_m2m_poll);
687 
688 int v4l2_m2m_mmap(struct file *file, struct v4l2_m2m_ctx *m2m_ctx,
689 			 struct vm_area_struct *vma)
690 {
691 	unsigned long offset = vma->vm_pgoff << PAGE_SHIFT;
692 	struct vb2_queue *vq;
693 
694 	if (offset < DST_QUEUE_OFF_BASE) {
695 		vq = v4l2_m2m_get_src_vq(m2m_ctx);
696 	} else {
697 		vq = v4l2_m2m_get_dst_vq(m2m_ctx);
698 		vma->vm_pgoff -= (DST_QUEUE_OFF_BASE >> PAGE_SHIFT);
699 	}
700 
701 	return vb2_mmap(vq, vma);
702 }
703 EXPORT_SYMBOL(v4l2_m2m_mmap);
704 
705 #if defined(CONFIG_MEDIA_CONTROLLER)
706 void v4l2_m2m_unregister_media_controller(struct v4l2_m2m_dev *m2m_dev)
707 {
708 	media_remove_intf_links(&m2m_dev->intf_devnode->intf);
709 	media_devnode_remove(m2m_dev->intf_devnode);
710 
711 	media_entity_remove_links(m2m_dev->source);
712 	media_entity_remove_links(&m2m_dev->sink);
713 	media_entity_remove_links(&m2m_dev->proc);
714 	media_device_unregister_entity(m2m_dev->source);
715 	media_device_unregister_entity(&m2m_dev->sink);
716 	media_device_unregister_entity(&m2m_dev->proc);
717 	kfree(m2m_dev->source->name);
718 	kfree(m2m_dev->sink.name);
719 	kfree(m2m_dev->proc.name);
720 }
721 EXPORT_SYMBOL_GPL(v4l2_m2m_unregister_media_controller);
722 
723 static int v4l2_m2m_register_entity(struct media_device *mdev,
724 	struct v4l2_m2m_dev *m2m_dev, enum v4l2_m2m_entity_type type,
725 	struct video_device *vdev, int function)
726 {
727 	struct media_entity *entity;
728 	struct media_pad *pads;
729 	char *name;
730 	unsigned int len;
731 	int num_pads;
732 	int ret;
733 
734 	switch (type) {
735 	case MEM2MEM_ENT_TYPE_SOURCE:
736 		entity = m2m_dev->source;
737 		pads = &m2m_dev->source_pad;
738 		pads[0].flags = MEDIA_PAD_FL_SOURCE;
739 		num_pads = 1;
740 		break;
741 	case MEM2MEM_ENT_TYPE_SINK:
742 		entity = &m2m_dev->sink;
743 		pads = &m2m_dev->sink_pad;
744 		pads[0].flags = MEDIA_PAD_FL_SINK;
745 		num_pads = 1;
746 		break;
747 	case MEM2MEM_ENT_TYPE_PROC:
748 		entity = &m2m_dev->proc;
749 		pads = m2m_dev->proc_pads;
750 		pads[0].flags = MEDIA_PAD_FL_SINK;
751 		pads[1].flags = MEDIA_PAD_FL_SOURCE;
752 		num_pads = 2;
753 		break;
754 	default:
755 		return -EINVAL;
756 	}
757 
758 	entity->obj_type = MEDIA_ENTITY_TYPE_BASE;
759 	if (type != MEM2MEM_ENT_TYPE_PROC) {
760 		entity->info.dev.major = VIDEO_MAJOR;
761 		entity->info.dev.minor = vdev->minor;
762 	}
763 	len = strlen(vdev->name) + 2 + strlen(m2m_entity_name[type]);
764 	name = kmalloc(len, GFP_KERNEL);
765 	if (!name)
766 		return -ENOMEM;
767 	snprintf(name, len, "%s-%s", vdev->name, m2m_entity_name[type]);
768 	entity->name = name;
769 	entity->function = function;
770 
771 	ret = media_entity_pads_init(entity, num_pads, pads);
772 	if (ret)
773 		return ret;
774 	ret = media_device_register_entity(mdev, entity);
775 	if (ret)
776 		return ret;
777 
778 	return 0;
779 }
780 
781 int v4l2_m2m_register_media_controller(struct v4l2_m2m_dev *m2m_dev,
782 		struct video_device *vdev, int function)
783 {
784 	struct media_device *mdev = vdev->v4l2_dev->mdev;
785 	struct media_link *link;
786 	int ret;
787 
788 	if (!mdev)
789 		return 0;
790 
791 	/* A memory-to-memory device consists in two
792 	 * DMA engine and one video processing entities.
793 	 * The DMA engine entities are linked to a V4L interface
794 	 */
795 
796 	/* Create the three entities with their pads */
797 	m2m_dev->source = &vdev->entity;
798 	ret = v4l2_m2m_register_entity(mdev, m2m_dev,
799 			MEM2MEM_ENT_TYPE_SOURCE, vdev, MEDIA_ENT_F_IO_V4L);
800 	if (ret)
801 		return ret;
802 	ret = v4l2_m2m_register_entity(mdev, m2m_dev,
803 			MEM2MEM_ENT_TYPE_PROC, vdev, function);
804 	if (ret)
805 		goto err_rel_entity0;
806 	ret = v4l2_m2m_register_entity(mdev, m2m_dev,
807 			MEM2MEM_ENT_TYPE_SINK, vdev, MEDIA_ENT_F_IO_V4L);
808 	if (ret)
809 		goto err_rel_entity1;
810 
811 	/* Connect the three entities */
812 	ret = media_create_pad_link(m2m_dev->source, 0, &m2m_dev->proc, 1,
813 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
814 	if (ret)
815 		goto err_rel_entity2;
816 
817 	ret = media_create_pad_link(&m2m_dev->proc, 0, &m2m_dev->sink, 0,
818 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
819 	if (ret)
820 		goto err_rm_links0;
821 
822 	/* Create video interface */
823 	m2m_dev->intf_devnode = media_devnode_create(mdev,
824 			MEDIA_INTF_T_V4L_VIDEO, 0,
825 			VIDEO_MAJOR, vdev->minor);
826 	if (!m2m_dev->intf_devnode) {
827 		ret = -ENOMEM;
828 		goto err_rm_links1;
829 	}
830 
831 	/* Connect the two DMA engines to the interface */
832 	link = media_create_intf_link(m2m_dev->source,
833 			&m2m_dev->intf_devnode->intf,
834 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
835 	if (!link) {
836 		ret = -ENOMEM;
837 		goto err_rm_devnode;
838 	}
839 
840 	link = media_create_intf_link(&m2m_dev->sink,
841 			&m2m_dev->intf_devnode->intf,
842 			MEDIA_LNK_FL_IMMUTABLE | MEDIA_LNK_FL_ENABLED);
843 	if (!link) {
844 		ret = -ENOMEM;
845 		goto err_rm_intf_link;
846 	}
847 	return 0;
848 
849 err_rm_intf_link:
850 	media_remove_intf_links(&m2m_dev->intf_devnode->intf);
851 err_rm_devnode:
852 	media_devnode_remove(m2m_dev->intf_devnode);
853 err_rm_links1:
854 	media_entity_remove_links(&m2m_dev->sink);
855 err_rm_links0:
856 	media_entity_remove_links(&m2m_dev->proc);
857 	media_entity_remove_links(m2m_dev->source);
858 err_rel_entity2:
859 	media_device_unregister_entity(&m2m_dev->proc);
860 	kfree(m2m_dev->proc.name);
861 err_rel_entity1:
862 	media_device_unregister_entity(&m2m_dev->sink);
863 	kfree(m2m_dev->sink.name);
864 err_rel_entity0:
865 	media_device_unregister_entity(m2m_dev->source);
866 	kfree(m2m_dev->source->name);
867 	return ret;
868 	return 0;
869 }
870 EXPORT_SYMBOL_GPL(v4l2_m2m_register_media_controller);
871 #endif
872 
873 struct v4l2_m2m_dev *v4l2_m2m_init(const struct v4l2_m2m_ops *m2m_ops)
874 {
875 	struct v4l2_m2m_dev *m2m_dev;
876 
877 	if (!m2m_ops || WARN_ON(!m2m_ops->device_run))
878 		return ERR_PTR(-EINVAL);
879 
880 	m2m_dev = kzalloc(sizeof *m2m_dev, GFP_KERNEL);
881 	if (!m2m_dev)
882 		return ERR_PTR(-ENOMEM);
883 
884 	m2m_dev->curr_ctx = NULL;
885 	m2m_dev->m2m_ops = m2m_ops;
886 	INIT_LIST_HEAD(&m2m_dev->job_queue);
887 	spin_lock_init(&m2m_dev->job_spinlock);
888 	INIT_WORK(&m2m_dev->job_work, v4l2_m2m_device_run_work);
889 
890 	return m2m_dev;
891 }
892 EXPORT_SYMBOL_GPL(v4l2_m2m_init);
893 
894 void v4l2_m2m_release(struct v4l2_m2m_dev *m2m_dev)
895 {
896 	kfree(m2m_dev);
897 }
898 EXPORT_SYMBOL_GPL(v4l2_m2m_release);
899 
900 struct v4l2_m2m_ctx *v4l2_m2m_ctx_init(struct v4l2_m2m_dev *m2m_dev,
901 		void *drv_priv,
902 		int (*queue_init)(void *priv, struct vb2_queue *src_vq, struct vb2_queue *dst_vq))
903 {
904 	struct v4l2_m2m_ctx *m2m_ctx;
905 	struct v4l2_m2m_queue_ctx *out_q_ctx, *cap_q_ctx;
906 	int ret;
907 
908 	m2m_ctx = kzalloc(sizeof *m2m_ctx, GFP_KERNEL);
909 	if (!m2m_ctx)
910 		return ERR_PTR(-ENOMEM);
911 
912 	m2m_ctx->priv = drv_priv;
913 	m2m_ctx->m2m_dev = m2m_dev;
914 	init_waitqueue_head(&m2m_ctx->finished);
915 
916 	out_q_ctx = &m2m_ctx->out_q_ctx;
917 	cap_q_ctx = &m2m_ctx->cap_q_ctx;
918 
919 	INIT_LIST_HEAD(&out_q_ctx->rdy_queue);
920 	INIT_LIST_HEAD(&cap_q_ctx->rdy_queue);
921 	spin_lock_init(&out_q_ctx->rdy_spinlock);
922 	spin_lock_init(&cap_q_ctx->rdy_spinlock);
923 
924 	INIT_LIST_HEAD(&m2m_ctx->queue);
925 
926 	ret = queue_init(drv_priv, &out_q_ctx->q, &cap_q_ctx->q);
927 
928 	if (ret)
929 		goto err;
930 	/*
931 	 * Both queues should use same the mutex to lock the m2m context.
932 	 * This lock is used in some v4l2_m2m_* helpers.
933 	 */
934 	if (WARN_ON(out_q_ctx->q.lock != cap_q_ctx->q.lock)) {
935 		ret = -EINVAL;
936 		goto err;
937 	}
938 	m2m_ctx->q_lock = out_q_ctx->q.lock;
939 
940 	return m2m_ctx;
941 err:
942 	kfree(m2m_ctx);
943 	return ERR_PTR(ret);
944 }
945 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_init);
946 
947 void v4l2_m2m_ctx_release(struct v4l2_m2m_ctx *m2m_ctx)
948 {
949 	/* wait until the current context is dequeued from job_queue */
950 	v4l2_m2m_cancel_job(m2m_ctx);
951 
952 	vb2_queue_release(&m2m_ctx->cap_q_ctx.q);
953 	vb2_queue_release(&m2m_ctx->out_q_ctx.q);
954 
955 	kfree(m2m_ctx);
956 }
957 EXPORT_SYMBOL_GPL(v4l2_m2m_ctx_release);
958 
959 void v4l2_m2m_buf_queue(struct v4l2_m2m_ctx *m2m_ctx,
960 		struct vb2_v4l2_buffer *vbuf)
961 {
962 	struct v4l2_m2m_buffer *b = container_of(vbuf,
963 				struct v4l2_m2m_buffer, vb);
964 	struct v4l2_m2m_queue_ctx *q_ctx;
965 	unsigned long flags;
966 
967 	q_ctx = get_queue_ctx(m2m_ctx, vbuf->vb2_buf.vb2_queue->type);
968 	if (!q_ctx)
969 		return;
970 
971 	spin_lock_irqsave(&q_ctx->rdy_spinlock, flags);
972 	list_add_tail(&b->list, &q_ctx->rdy_queue);
973 	q_ctx->num_rdy++;
974 	spin_unlock_irqrestore(&q_ctx->rdy_spinlock, flags);
975 }
976 EXPORT_SYMBOL_GPL(v4l2_m2m_buf_queue);
977 
978 void v4l2_m2m_request_queue(struct media_request *req)
979 {
980 	struct media_request_object *obj, *obj_safe;
981 	struct v4l2_m2m_ctx *m2m_ctx = NULL;
982 
983 	/*
984 	 * Queue all objects. Note that buffer objects are at the end of the
985 	 * objects list, after all other object types. Once buffer objects
986 	 * are queued, the driver might delete them immediately (if the driver
987 	 * processes the buffer at once), so we have to use
988 	 * list_for_each_entry_safe() to handle the case where the object we
989 	 * queue is deleted.
990 	 */
991 	list_for_each_entry_safe(obj, obj_safe, &req->objects, list) {
992 		struct v4l2_m2m_ctx *m2m_ctx_obj;
993 		struct vb2_buffer *vb;
994 
995 		if (!obj->ops->queue)
996 			continue;
997 
998 		if (vb2_request_object_is_buffer(obj)) {
999 			/* Sanity checks */
1000 			vb = container_of(obj, struct vb2_buffer, req_obj);
1001 			WARN_ON(!V4L2_TYPE_IS_OUTPUT(vb->vb2_queue->type));
1002 			m2m_ctx_obj = container_of(vb->vb2_queue,
1003 						   struct v4l2_m2m_ctx,
1004 						   out_q_ctx.q);
1005 			WARN_ON(m2m_ctx && m2m_ctx_obj != m2m_ctx);
1006 			m2m_ctx = m2m_ctx_obj;
1007 		}
1008 
1009 		/*
1010 		 * The buffer we queue here can in theory be immediately
1011 		 * unbound, hence the use of list_for_each_entry_safe()
1012 		 * above and why we call the queue op last.
1013 		 */
1014 		obj->ops->queue(obj);
1015 	}
1016 
1017 	WARN_ON(!m2m_ctx);
1018 
1019 	if (m2m_ctx)
1020 		v4l2_m2m_try_schedule(m2m_ctx);
1021 }
1022 EXPORT_SYMBOL_GPL(v4l2_m2m_request_queue);
1023 
1024 /* Videobuf2 ioctl helpers */
1025 
1026 int v4l2_m2m_ioctl_reqbufs(struct file *file, void *priv,
1027 				struct v4l2_requestbuffers *rb)
1028 {
1029 	struct v4l2_fh *fh = file->private_data;
1030 
1031 	return v4l2_m2m_reqbufs(file, fh->m2m_ctx, rb);
1032 }
1033 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_reqbufs);
1034 
1035 int v4l2_m2m_ioctl_create_bufs(struct file *file, void *priv,
1036 				struct v4l2_create_buffers *create)
1037 {
1038 	struct v4l2_fh *fh = file->private_data;
1039 
1040 	return v4l2_m2m_create_bufs(file, fh->m2m_ctx, create);
1041 }
1042 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_create_bufs);
1043 
1044 int v4l2_m2m_ioctl_querybuf(struct file *file, void *priv,
1045 				struct v4l2_buffer *buf)
1046 {
1047 	struct v4l2_fh *fh = file->private_data;
1048 
1049 	return v4l2_m2m_querybuf(file, fh->m2m_ctx, buf);
1050 }
1051 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_querybuf);
1052 
1053 int v4l2_m2m_ioctl_qbuf(struct file *file, void *priv,
1054 				struct v4l2_buffer *buf)
1055 {
1056 	struct v4l2_fh *fh = file->private_data;
1057 
1058 	return v4l2_m2m_qbuf(file, fh->m2m_ctx, buf);
1059 }
1060 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_qbuf);
1061 
1062 int v4l2_m2m_ioctl_dqbuf(struct file *file, void *priv,
1063 				struct v4l2_buffer *buf)
1064 {
1065 	struct v4l2_fh *fh = file->private_data;
1066 
1067 	return v4l2_m2m_dqbuf(file, fh->m2m_ctx, buf);
1068 }
1069 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_dqbuf);
1070 
1071 int v4l2_m2m_ioctl_prepare_buf(struct file *file, void *priv,
1072 			       struct v4l2_buffer *buf)
1073 {
1074 	struct v4l2_fh *fh = file->private_data;
1075 
1076 	return v4l2_m2m_prepare_buf(file, fh->m2m_ctx, buf);
1077 }
1078 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_prepare_buf);
1079 
1080 int v4l2_m2m_ioctl_expbuf(struct file *file, void *priv,
1081 				struct v4l2_exportbuffer *eb)
1082 {
1083 	struct v4l2_fh *fh = file->private_data;
1084 
1085 	return v4l2_m2m_expbuf(file, fh->m2m_ctx, eb);
1086 }
1087 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_expbuf);
1088 
1089 int v4l2_m2m_ioctl_streamon(struct file *file, void *priv,
1090 				enum v4l2_buf_type type)
1091 {
1092 	struct v4l2_fh *fh = file->private_data;
1093 
1094 	return v4l2_m2m_streamon(file, fh->m2m_ctx, type);
1095 }
1096 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamon);
1097 
1098 int v4l2_m2m_ioctl_streamoff(struct file *file, void *priv,
1099 				enum v4l2_buf_type type)
1100 {
1101 	struct v4l2_fh *fh = file->private_data;
1102 
1103 	return v4l2_m2m_streamoff(file, fh->m2m_ctx, type);
1104 }
1105 EXPORT_SYMBOL_GPL(v4l2_m2m_ioctl_streamoff);
1106 
1107 /*
1108  * v4l2_file_operations helpers. It is assumed here same lock is used
1109  * for the output and the capture buffer queue.
1110  */
1111 
1112 int v4l2_m2m_fop_mmap(struct file *file, struct vm_area_struct *vma)
1113 {
1114 	struct v4l2_fh *fh = file->private_data;
1115 
1116 	return v4l2_m2m_mmap(file, fh->m2m_ctx, vma);
1117 }
1118 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_mmap);
1119 
1120 __poll_t v4l2_m2m_fop_poll(struct file *file, poll_table *wait)
1121 {
1122 	struct v4l2_fh *fh = file->private_data;
1123 	struct v4l2_m2m_ctx *m2m_ctx = fh->m2m_ctx;
1124 	__poll_t ret;
1125 
1126 	if (m2m_ctx->q_lock)
1127 		mutex_lock(m2m_ctx->q_lock);
1128 
1129 	ret = v4l2_m2m_poll(file, m2m_ctx, wait);
1130 
1131 	if (m2m_ctx->q_lock)
1132 		mutex_unlock(m2m_ctx->q_lock);
1133 
1134 	return ret;
1135 }
1136 EXPORT_SYMBOL_GPL(v4l2_m2m_fop_poll);
1137 
1138