xref: /linux/sound/soc/fsl/imx-pcm-rpmsg.c (revision 60684c2bd35064043360e6f716d1b7c20e967b7d)
1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2017-2021 NXP
3 
4 #include <linux/dma-mapping.h>
5 #include <linux/slab.h>
6 #include <linux/module.h>
7 #include <linux/delay.h>
8 #include <linux/rpmsg.h>
9 #include <sound/core.h>
10 #include <sound/pcm.h>
11 #include <sound/pcm_params.h>
12 #include <sound/dmaengine_pcm.h>
13 #include <sound/soc.h>
14 
15 #include "imx-pcm.h"
16 #include "fsl_rpmsg.h"
17 #include "imx-pcm-rpmsg.h"
18 
19 static struct snd_pcm_hardware imx_rpmsg_pcm_hardware = {
20 	.info = SNDRV_PCM_INFO_INTERLEAVED |
21 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
22 		SNDRV_PCM_INFO_MMAP |
23 		SNDRV_PCM_INFO_MMAP_VALID |
24 		SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
25 		SNDRV_PCM_INFO_PAUSE |
26 		SNDRV_PCM_INFO_RESUME,
27 	.buffer_bytes_max = IMX_DEFAULT_DMABUF_SIZE,
28 	.period_bytes_min = 512,
29 	.period_bytes_max = 65536,
30 	.periods_min = 2,
31 	.periods_max = 6000,
32 	.fifo_size = 0,
33 };
34 
35 static int imx_rpmsg_pcm_send_message(struct rpmsg_msg *msg,
36 				      struct rpmsg_info *info)
37 {
38 	struct rpmsg_device *rpdev = info->rpdev;
39 	int ret = 0;
40 
41 	mutex_lock(&info->msg_lock);
42 	if (!rpdev) {
43 		dev_err(info->dev, "rpmsg channel not ready\n");
44 		mutex_unlock(&info->msg_lock);
45 		return -EINVAL;
46 	}
47 
48 	dev_dbg(&rpdev->dev, "send cmd %d\n", msg->s_msg.header.cmd);
49 
50 	if (!(msg->s_msg.header.type == MSG_TYPE_C))
51 		reinit_completion(&info->cmd_complete);
52 
53 	ret = rpmsg_send(rpdev->ept, (void *)&msg->s_msg,
54 			 sizeof(struct rpmsg_s_msg));
55 	if (ret) {
56 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
57 		mutex_unlock(&info->msg_lock);
58 		return ret;
59 	}
60 
61 	/* No receive msg for TYPE_C command */
62 	if (msg->s_msg.header.type == MSG_TYPE_C) {
63 		mutex_unlock(&info->msg_lock);
64 		return 0;
65 	}
66 
67 	/* wait response from rpmsg */
68 	ret = wait_for_completion_timeout(&info->cmd_complete,
69 					  msecs_to_jiffies(RPMSG_TIMEOUT));
70 	if (!ret) {
71 		dev_err(&rpdev->dev, "rpmsg_send cmd %d timeout!\n",
72 			msg->s_msg.header.cmd);
73 		mutex_unlock(&info->msg_lock);
74 		return -ETIMEDOUT;
75 	}
76 
77 	memcpy(&msg->r_msg, &info->r_msg, sizeof(struct rpmsg_r_msg));
78 	memcpy(&info->msg[msg->r_msg.header.cmd].r_msg,
79 	       &msg->r_msg, sizeof(struct rpmsg_r_msg));
80 
81 	/*
82 	 * Reset the buffer pointer to be zero, actully we have
83 	 * set the buffer pointer to be zero in imx_rpmsg_terminate_all
84 	 * But if there is timer task queued in queue, after it is
85 	 * executed the buffer pointer will be changed, so need to
86 	 * reset it again with TERMINATE command.
87 	 */
88 	switch (msg->s_msg.header.cmd) {
89 	case TX_TERMINATE:
90 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
91 		break;
92 	case RX_TERMINATE:
93 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
94 		break;
95 	default:
96 		break;
97 	}
98 
99 	dev_dbg(&rpdev->dev, "cmd:%d, resp %d\n", msg->s_msg.header.cmd,
100 		info->r_msg.param.resp);
101 
102 	mutex_unlock(&info->msg_lock);
103 
104 	return 0;
105 }
106 
107 static int imx_rpmsg_insert_workqueue(struct snd_pcm_substream *substream,
108 				      struct rpmsg_msg *msg,
109 				      struct rpmsg_info *info)
110 {
111 	unsigned long flags;
112 	int ret = 0;
113 
114 	/*
115 	 * Queue the work to workqueue.
116 	 * If the queue is full, drop the message.
117 	 */
118 	spin_lock_irqsave(&info->wq_lock, flags);
119 	if (info->work_write_index != info->work_read_index) {
120 		int index = info->work_write_index;
121 
122 		memcpy(&info->work_list[index].msg, msg,
123 		       sizeof(struct rpmsg_s_msg));
124 
125 		queue_work(info->rpmsg_wq, &info->work_list[index].work);
126 		info->work_write_index++;
127 		info->work_write_index %= WORK_MAX_NUM;
128 	} else {
129 		info->msg_drop_count[substream->stream]++;
130 		ret = -EPIPE;
131 	}
132 	spin_unlock_irqrestore(&info->wq_lock, flags);
133 
134 	return ret;
135 }
136 
137 static int imx_rpmsg_pcm_hw_params(struct snd_soc_component *component,
138 				   struct snd_pcm_substream *substream,
139 				   struct snd_pcm_hw_params *params)
140 {
141 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
142 	struct rpmsg_msg *msg;
143 
144 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
145 		msg = &info->msg[TX_HW_PARAM];
146 		msg->s_msg.header.cmd = TX_HW_PARAM;
147 	} else {
148 		msg = &info->msg[RX_HW_PARAM];
149 		msg->s_msg.header.cmd = RX_HW_PARAM;
150 	}
151 
152 	msg->s_msg.param.rate = params_rate(params);
153 
154 	switch (params_format(params)) {
155 	case SNDRV_PCM_FORMAT_S16_LE:
156 		msg->s_msg.param.format   = RPMSG_S16_LE;
157 		break;
158 	case SNDRV_PCM_FORMAT_S24_LE:
159 		msg->s_msg.param.format   = RPMSG_S24_LE;
160 		break;
161 	case SNDRV_PCM_FORMAT_DSD_U16_LE:
162 		msg->s_msg.param.format   = RPMSG_DSD_U16_LE;
163 		break;
164 	case SNDRV_PCM_FORMAT_DSD_U32_LE:
165 		msg->s_msg.param.format   = RPMSG_DSD_U32_LE;
166 		break;
167 	default:
168 		msg->s_msg.param.format   = RPMSG_S32_LE;
169 		break;
170 	}
171 
172 	switch (params_channels(params)) {
173 	case 1:
174 		msg->s_msg.param.channels = RPMSG_CH_LEFT;
175 		break;
176 	case 2:
177 		msg->s_msg.param.channels = RPMSG_CH_STEREO;
178 		break;
179 	default:
180 		msg->s_msg.param.channels = params_channels(params);
181 		break;
182 	}
183 
184 	info->send_message(msg, info);
185 
186 	return 0;
187 }
188 
189 static snd_pcm_uframes_t imx_rpmsg_pcm_pointer(struct snd_soc_component *component,
190 					       struct snd_pcm_substream *substream)
191 {
192 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
193 	struct rpmsg_msg *msg;
194 	unsigned int pos = 0;
195 	int buffer_tail = 0;
196 
197 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
198 		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
199 	else
200 		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
201 
202 	buffer_tail = msg->r_msg.param.buffer_tail;
203 	pos = buffer_tail * snd_pcm_lib_period_bytes(substream);
204 
205 	return bytes_to_frames(substream->runtime, pos);
206 }
207 
208 static void imx_rpmsg_timer_callback(struct timer_list *t)
209 {
210 	struct stream_timer  *stream_timer =
211 			from_timer(stream_timer, t, timer);
212 	struct snd_pcm_substream *substream = stream_timer->substream;
213 	struct rpmsg_info *info = stream_timer->info;
214 	struct rpmsg_msg *msg;
215 
216 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
217 		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
218 		msg->s_msg.header.cmd = TX_PERIOD_DONE;
219 	} else {
220 		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
221 		msg->s_msg.header.cmd = RX_PERIOD_DONE;
222 	}
223 
224 	imx_rpmsg_insert_workqueue(substream, msg, info);
225 }
226 
227 static int imx_rpmsg_pcm_open(struct snd_soc_component *component,
228 			      struct snd_pcm_substream *substream)
229 {
230 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
231 	struct rpmsg_msg *msg;
232 	int ret = 0;
233 	int cmd;
234 
235 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
236 		msg = &info->msg[TX_OPEN];
237 		msg->s_msg.header.cmd = TX_OPEN;
238 
239 		/* reinitialize buffer counter*/
240 		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
241 		info->msg[cmd].s_msg.param.buffer_tail = 0;
242 		info->msg[cmd].r_msg.param.buffer_tail = 0;
243 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
244 
245 	} else {
246 		msg = &info->msg[RX_OPEN];
247 		msg->s_msg.header.cmd = RX_OPEN;
248 
249 		/* reinitialize buffer counter*/
250 		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
251 		info->msg[cmd].s_msg.param.buffer_tail = 0;
252 		info->msg[cmd].r_msg.param.buffer_tail = 0;
253 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
254 	}
255 
256 	info->send_message(msg, info);
257 
258 	imx_rpmsg_pcm_hardware.period_bytes_max =
259 			imx_rpmsg_pcm_hardware.buffer_bytes_max / 2;
260 
261 	snd_soc_set_runtime_hwparams(substream, &imx_rpmsg_pcm_hardware);
262 
263 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
264 					    SNDRV_PCM_HW_PARAM_PERIODS);
265 	if (ret < 0)
266 		return ret;
267 
268 	info->msg_drop_count[substream->stream] = 0;
269 
270 	/* Create timer*/
271 	info->stream_timer[substream->stream].info = info;
272 	info->stream_timer[substream->stream].substream = substream;
273 	timer_setup(&info->stream_timer[substream->stream].timer,
274 		    imx_rpmsg_timer_callback, 0);
275 	return ret;
276 }
277 
278 static int imx_rpmsg_pcm_close(struct snd_soc_component *component,
279 			       struct snd_pcm_substream *substream)
280 {
281 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
282 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
283 	struct rpmsg_msg *msg;
284 
285 	/* Flush work in workqueue to make TX_CLOSE is the last message */
286 	flush_workqueue(info->rpmsg_wq);
287 
288 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
289 		msg = &info->msg[TX_CLOSE];
290 		msg->s_msg.header.cmd = TX_CLOSE;
291 	} else {
292 		msg = &info->msg[RX_CLOSE];
293 		msg->s_msg.header.cmd = RX_CLOSE;
294 	}
295 
296 	info->send_message(msg, info);
297 
298 	del_timer(&info->stream_timer[substream->stream].timer);
299 
300 	rtd->dai_link->ignore_suspend = 0;
301 
302 	if (info->msg_drop_count[substream->stream])
303 		dev_warn(rtd->dev, "Msg is dropped!, number is %d\n",
304 			 info->msg_drop_count[substream->stream]);
305 
306 	return 0;
307 }
308 
309 static int imx_rpmsg_pcm_prepare(struct snd_soc_component *component,
310 				 struct snd_pcm_substream *substream)
311 {
312 	struct snd_pcm_runtime *runtime = substream->runtime;
313 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
314 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
315 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
316 
317 	/*
318 	 * NON-MMAP mode, NONBLOCK, Version 2, enable lpa in dts
319 	 * four conditions to determine the lpa is enabled.
320 	 */
321 	if ((runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
322 	     runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) &&
323 	     rpmsg->enable_lpa) {
324 		/*
325 		 * Ignore suspend operation in low power mode
326 		 * M core will continue playback music on A core suspend.
327 		 */
328 		rtd->dai_link->ignore_suspend = 1;
329 		rpmsg->force_lpa = 1;
330 	} else {
331 		rpmsg->force_lpa = 0;
332 	}
333 
334 	return 0;
335 }
336 
337 static void imx_rpmsg_pcm_dma_complete(void *arg)
338 {
339 	struct snd_pcm_substream *substream = arg;
340 
341 	snd_pcm_period_elapsed(substream);
342 }
343 
344 static int imx_rpmsg_prepare_and_submit(struct snd_soc_component *component,
345 					struct snd_pcm_substream *substream)
346 {
347 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
348 	struct rpmsg_msg *msg;
349 
350 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
351 		msg = &info->msg[TX_BUFFER];
352 		msg->s_msg.header.cmd = TX_BUFFER;
353 	} else {
354 		msg = &info->msg[RX_BUFFER];
355 		msg->s_msg.header.cmd = RX_BUFFER;
356 	}
357 
358 	/* Send buffer address and buffer size */
359 	msg->s_msg.param.buffer_addr = substream->runtime->dma_addr;
360 	msg->s_msg.param.buffer_size = snd_pcm_lib_buffer_bytes(substream);
361 	msg->s_msg.param.period_size = snd_pcm_lib_period_bytes(substream);
362 	msg->s_msg.param.buffer_tail = 0;
363 
364 	info->num_period[substream->stream] = msg->s_msg.param.buffer_size /
365 					      msg->s_msg.param.period_size;
366 
367 	info->callback[substream->stream] = imx_rpmsg_pcm_dma_complete;
368 	info->callback_param[substream->stream] = substream;
369 
370 	return imx_rpmsg_insert_workqueue(substream, msg, info);
371 }
372 
373 static int imx_rpmsg_async_issue_pending(struct snd_soc_component *component,
374 					 struct snd_pcm_substream *substream)
375 {
376 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
377 	struct rpmsg_msg *msg;
378 
379 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
380 		msg = &info->msg[TX_START];
381 		msg->s_msg.header.cmd = TX_START;
382 	} else {
383 		msg = &info->msg[RX_START];
384 		msg->s_msg.header.cmd = RX_START;
385 	}
386 
387 	return imx_rpmsg_insert_workqueue(substream, msg, info);
388 }
389 
390 static int imx_rpmsg_restart(struct snd_soc_component *component,
391 			     struct snd_pcm_substream *substream)
392 {
393 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
394 	struct rpmsg_msg *msg;
395 
396 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
397 		msg = &info->msg[TX_RESTART];
398 		msg->s_msg.header.cmd = TX_RESTART;
399 	} else {
400 		msg = &info->msg[RX_RESTART];
401 		msg->s_msg.header.cmd = RX_RESTART;
402 	}
403 
404 	return imx_rpmsg_insert_workqueue(substream, msg, info);
405 }
406 
407 static int imx_rpmsg_pause(struct snd_soc_component *component,
408 			   struct snd_pcm_substream *substream)
409 {
410 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
411 	struct rpmsg_msg *msg;
412 
413 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
414 		msg = &info->msg[TX_PAUSE];
415 		msg->s_msg.header.cmd = TX_PAUSE;
416 	} else {
417 		msg = &info->msg[RX_PAUSE];
418 		msg->s_msg.header.cmd = RX_PAUSE;
419 	}
420 
421 	return imx_rpmsg_insert_workqueue(substream, msg, info);
422 }
423 
424 static int imx_rpmsg_terminate_all(struct snd_soc_component *component,
425 				   struct snd_pcm_substream *substream)
426 {
427 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
428 	struct rpmsg_msg *msg;
429 	int cmd;
430 
431 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
432 		msg = &info->msg[TX_TERMINATE];
433 		msg->s_msg.header.cmd = TX_TERMINATE;
434 		/* Clear buffer count*/
435 		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
436 		info->msg[cmd].s_msg.param.buffer_tail = 0;
437 		info->msg[cmd].r_msg.param.buffer_tail = 0;
438 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
439 	} else {
440 		msg = &info->msg[RX_TERMINATE];
441 		msg->s_msg.header.cmd = RX_TERMINATE;
442 		/* Clear buffer count*/
443 		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
444 		info->msg[cmd].s_msg.param.buffer_tail = 0;
445 		info->msg[cmd].r_msg.param.buffer_tail = 0;
446 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
447 	}
448 
449 	del_timer(&info->stream_timer[substream->stream].timer);
450 
451 	return imx_rpmsg_insert_workqueue(substream, msg, info);
452 }
453 
454 static int imx_rpmsg_pcm_trigger(struct snd_soc_component *component,
455 				 struct snd_pcm_substream *substream, int cmd)
456 {
457 	struct snd_pcm_runtime *runtime = substream->runtime;
458 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
459 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
460 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
461 	int ret = 0;
462 
463 	switch (cmd) {
464 	case SNDRV_PCM_TRIGGER_START:
465 		ret = imx_rpmsg_prepare_and_submit(component, substream);
466 		if (ret)
467 			return ret;
468 		ret = imx_rpmsg_async_issue_pending(component, substream);
469 		break;
470 	case SNDRV_PCM_TRIGGER_RESUME:
471 		if (rpmsg->force_lpa)
472 			break;
473 		fallthrough;
474 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
475 		ret = imx_rpmsg_restart(component, substream);
476 		break;
477 	case SNDRV_PCM_TRIGGER_SUSPEND:
478 		if (!rpmsg->force_lpa) {
479 			if (runtime->info & SNDRV_PCM_INFO_PAUSE)
480 				ret = imx_rpmsg_pause(component, substream);
481 			else
482 				ret = imx_rpmsg_terminate_all(component, substream);
483 		}
484 		break;
485 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
486 		ret = imx_rpmsg_pause(component, substream);
487 		break;
488 	case SNDRV_PCM_TRIGGER_STOP:
489 		ret = imx_rpmsg_terminate_all(component, substream);
490 		break;
491 	default:
492 		return -EINVAL;
493 	}
494 
495 	if (ret)
496 		return ret;
497 
498 	return 0;
499 }
500 
501 /*
502  * imx_rpmsg_pcm_ack
503  *
504  * Send the period index to M core through rpmsg, but not send
505  * all the period index to M core, reduce some unnessesary msg
506  * to reduce the pressure of rpmsg bandwidth.
507  */
508 static int imx_rpmsg_pcm_ack(struct snd_soc_component *component,
509 			     struct snd_pcm_substream *substream)
510 {
511 	struct snd_pcm_runtime *runtime = substream->runtime;
512 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
513 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
514 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
515 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
516 	snd_pcm_uframes_t period_size = runtime->period_size;
517 	snd_pcm_sframes_t avail;
518 	struct timer_list *timer;
519 	struct rpmsg_msg *msg;
520 	unsigned long flags;
521 	int buffer_tail = 0;
522 	int written_num;
523 
524 	if (!rpmsg->force_lpa)
525 		return 0;
526 
527 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
528 		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
529 		msg->s_msg.header.cmd = TX_PERIOD_DONE;
530 	} else {
531 		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
532 		msg->s_msg.header.cmd = RX_PERIOD_DONE;
533 	}
534 
535 	msg->s_msg.header.type = MSG_TYPE_C;
536 
537 	buffer_tail = (frames_to_bytes(runtime, runtime->control->appl_ptr) %
538 		       snd_pcm_lib_buffer_bytes(substream));
539 	buffer_tail = buffer_tail / snd_pcm_lib_period_bytes(substream);
540 
541 	/* There is update for period index */
542 	if (buffer_tail != msg->s_msg.param.buffer_tail) {
543 		written_num = buffer_tail - msg->s_msg.param.buffer_tail;
544 		if (written_num < 0)
545 			written_num += runtime->periods;
546 
547 		msg->s_msg.param.buffer_tail = buffer_tail;
548 
549 		/* The notification message is updated to latest */
550 		spin_lock_irqsave(&info->lock[substream->stream], flags);
551 		memcpy(&info->notify[substream->stream], msg,
552 		       sizeof(struct rpmsg_s_msg));
553 		info->notify_updated[substream->stream] = true;
554 		spin_unlock_irqrestore(&info->lock[substream->stream], flags);
555 
556 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
557 			avail = snd_pcm_playback_hw_avail(runtime);
558 		else
559 			avail = snd_pcm_capture_hw_avail(runtime);
560 
561 		timer = &info->stream_timer[substream->stream].timer;
562 		/*
563 		 * If the data in the buffer is less than one period before
564 		 * this fill, which means the data may not enough on M
565 		 * core side, we need to send message immediately to let
566 		 * M core know the pointer is updated.
567 		 * if there is more than one period data in the buffer before
568 		 * this fill, which means the data is enough on M core side,
569 		 * we can delay one period (using timer) to send the message
570 		 * for reduce the message number in workqueue, because the
571 		 * pointer may be updated by ack function later, we can
572 		 * send latest pointer to M core side.
573 		 */
574 		if ((avail - written_num * period_size) <= period_size) {
575 			imx_rpmsg_insert_workqueue(substream, msg, info);
576 		} else if (rpmsg->force_lpa && !timer_pending(timer)) {
577 			int time_msec;
578 
579 			time_msec = (int)(runtime->period_size * 1000 / runtime->rate);
580 			mod_timer(timer, jiffies + msecs_to_jiffies(time_msec));
581 		}
582 	}
583 
584 	return 0;
585 }
586 
587 static int imx_rpmsg_pcm_new(struct snd_soc_component *component,
588 			     struct snd_soc_pcm_runtime *rtd)
589 {
590 	struct snd_card *card = rtd->card->snd_card;
591 	struct snd_pcm *pcm = rtd->pcm;
592 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
593 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
594 	int ret;
595 
596 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
597 	if (ret)
598 		return ret;
599 
600 	imx_rpmsg_pcm_hardware.buffer_bytes_max = rpmsg->buffer_size;
601 	return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_WC,
602 					    pcm->card->dev, rpmsg->buffer_size);
603 }
604 
605 static const struct snd_soc_component_driver imx_rpmsg_soc_component = {
606 	.name		= IMX_PCM_DRV_NAME,
607 	.pcm_construct	= imx_rpmsg_pcm_new,
608 	.open		= imx_rpmsg_pcm_open,
609 	.close		= imx_rpmsg_pcm_close,
610 	.hw_params	= imx_rpmsg_pcm_hw_params,
611 	.trigger	= imx_rpmsg_pcm_trigger,
612 	.pointer	= imx_rpmsg_pcm_pointer,
613 	.ack		= imx_rpmsg_pcm_ack,
614 	.prepare	= imx_rpmsg_pcm_prepare,
615 };
616 
617 static void imx_rpmsg_pcm_work(struct work_struct *work)
618 {
619 	struct work_of_rpmsg *work_of_rpmsg;
620 	bool is_notification = false;
621 	struct rpmsg_info *info;
622 	struct rpmsg_msg msg;
623 	unsigned long flags;
624 
625 	work_of_rpmsg = container_of(work, struct work_of_rpmsg, work);
626 	info = work_of_rpmsg->info;
627 
628 	/*
629 	 * Every work in the work queue, first we check if there
630 	 * is update for period is filled, because there may be not
631 	 * enough data in M core side, need to let M core know
632 	 * data is updated immediately.
633 	 */
634 	spin_lock_irqsave(&info->lock[TX], flags);
635 	if (info->notify_updated[TX]) {
636 		memcpy(&msg, &info->notify[TX], sizeof(struct rpmsg_s_msg));
637 		info->notify_updated[TX] = false;
638 		spin_unlock_irqrestore(&info->lock[TX], flags);
639 		info->send_message(&msg, info);
640 	} else {
641 		spin_unlock_irqrestore(&info->lock[TX], flags);
642 	}
643 
644 	spin_lock_irqsave(&info->lock[RX], flags);
645 	if (info->notify_updated[RX]) {
646 		memcpy(&msg, &info->notify[RX], sizeof(struct rpmsg_s_msg));
647 		info->notify_updated[RX] = false;
648 		spin_unlock_irqrestore(&info->lock[RX], flags);
649 		info->send_message(&msg, info);
650 	} else {
651 		spin_unlock_irqrestore(&info->lock[RX], flags);
652 	}
653 
654 	/* Skip the notification message for it has been processed above */
655 	if (work_of_rpmsg->msg.s_msg.header.type == MSG_TYPE_C &&
656 	    (work_of_rpmsg->msg.s_msg.header.cmd == TX_PERIOD_DONE ||
657 	     work_of_rpmsg->msg.s_msg.header.cmd == RX_PERIOD_DONE))
658 		is_notification = true;
659 
660 	if (!is_notification)
661 		info->send_message(&work_of_rpmsg->msg, info);
662 
663 	/* update read index */
664 	spin_lock_irqsave(&info->wq_lock, flags);
665 	info->work_read_index++;
666 	info->work_read_index %= WORK_MAX_NUM;
667 	spin_unlock_irqrestore(&info->wq_lock, flags);
668 }
669 
670 static int imx_rpmsg_pcm_probe(struct platform_device *pdev)
671 {
672 	struct snd_soc_component *component;
673 	struct rpmsg_info *info;
674 	int ret, i;
675 
676 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
677 	if (!info)
678 		return -ENOMEM;
679 
680 	platform_set_drvdata(pdev, info);
681 
682 	info->rpdev = container_of(pdev->dev.parent, struct rpmsg_device, dev);
683 	info->dev = &pdev->dev;
684 	/* Setup work queue */
685 	info->rpmsg_wq = alloc_ordered_workqueue(info->rpdev->id.name,
686 						 WQ_HIGHPRI |
687 						 WQ_UNBOUND |
688 						 WQ_FREEZABLE);
689 	if (!info->rpmsg_wq) {
690 		dev_err(&pdev->dev, "workqueue create failed\n");
691 		return -ENOMEM;
692 	}
693 
694 	/* Write index initialize 1, make it differ with the read index */
695 	info->work_write_index = 1;
696 	info->send_message = imx_rpmsg_pcm_send_message;
697 
698 	for (i = 0; i < WORK_MAX_NUM; i++) {
699 		INIT_WORK(&info->work_list[i].work, imx_rpmsg_pcm_work);
700 		info->work_list[i].info = info;
701 	}
702 
703 	/* Initialize msg */
704 	for (i = 0; i < MSG_MAX_NUM; i++) {
705 		info->msg[i].s_msg.header.cate  = IMX_RPMSG_AUDIO;
706 		info->msg[i].s_msg.header.major = IMX_RMPSG_MAJOR;
707 		info->msg[i].s_msg.header.minor = IMX_RMPSG_MINOR;
708 		info->msg[i].s_msg.header.type  = MSG_TYPE_A;
709 		info->msg[i].s_msg.param.audioindex = 0;
710 	}
711 
712 	init_completion(&info->cmd_complete);
713 	mutex_init(&info->msg_lock);
714 	spin_lock_init(&info->lock[TX]);
715 	spin_lock_init(&info->lock[RX]);
716 	spin_lock_init(&info->wq_lock);
717 
718 	ret = devm_snd_soc_register_component(&pdev->dev,
719 					      &imx_rpmsg_soc_component,
720 					      NULL, 0);
721 	if (ret)
722 		goto fail;
723 
724 	component = snd_soc_lookup_component(&pdev->dev, NULL);
725 	if (!component) {
726 		ret = -EINVAL;
727 		goto fail;
728 	}
729 
730 	/* platform component name is used by machine driver to link with */
731 	component->name = info->rpdev->id.name;
732 
733 #ifdef CONFIG_DEBUG_FS
734 	component->debugfs_prefix = "rpmsg";
735 #endif
736 
737 	return 0;
738 
739 fail:
740 	if (info->rpmsg_wq)
741 		destroy_workqueue(info->rpmsg_wq);
742 
743 	return ret;
744 }
745 
746 static int imx_rpmsg_pcm_remove(struct platform_device *pdev)
747 {
748 	struct rpmsg_info *info = platform_get_drvdata(pdev);
749 
750 	if (info->rpmsg_wq)
751 		destroy_workqueue(info->rpmsg_wq);
752 
753 	return 0;
754 }
755 
756 #ifdef CONFIG_PM
757 static int imx_rpmsg_pcm_runtime_resume(struct device *dev)
758 {
759 	struct rpmsg_info *info = dev_get_drvdata(dev);
760 
761 	cpu_latency_qos_add_request(&info->pm_qos_req, 0);
762 
763 	return 0;
764 }
765 
766 static int imx_rpmsg_pcm_runtime_suspend(struct device *dev)
767 {
768 	struct rpmsg_info *info = dev_get_drvdata(dev);
769 
770 	cpu_latency_qos_remove_request(&info->pm_qos_req);
771 
772 	return 0;
773 }
774 #endif
775 
776 #ifdef CONFIG_PM_SLEEP
777 static int imx_rpmsg_pcm_suspend(struct device *dev)
778 {
779 	struct rpmsg_info *info = dev_get_drvdata(dev);
780 	struct rpmsg_msg *rpmsg_tx;
781 	struct rpmsg_msg *rpmsg_rx;
782 
783 	rpmsg_tx = &info->msg[TX_SUSPEND];
784 	rpmsg_rx = &info->msg[RX_SUSPEND];
785 
786 	rpmsg_tx->s_msg.header.cmd = TX_SUSPEND;
787 	info->send_message(rpmsg_tx, info);
788 
789 	rpmsg_rx->s_msg.header.cmd = RX_SUSPEND;
790 	info->send_message(rpmsg_rx, info);
791 
792 	return 0;
793 }
794 
795 static int imx_rpmsg_pcm_resume(struct device *dev)
796 {
797 	struct rpmsg_info *info = dev_get_drvdata(dev);
798 	struct rpmsg_msg *rpmsg_tx;
799 	struct rpmsg_msg *rpmsg_rx;
800 
801 	rpmsg_tx = &info->msg[TX_RESUME];
802 	rpmsg_rx = &info->msg[RX_RESUME];
803 
804 	rpmsg_tx->s_msg.header.cmd = TX_RESUME;
805 	info->send_message(rpmsg_tx, info);
806 
807 	rpmsg_rx->s_msg.header.cmd = RX_RESUME;
808 	info->send_message(rpmsg_rx, info);
809 
810 	return 0;
811 }
812 #endif /* CONFIG_PM_SLEEP */
813 
814 static const struct dev_pm_ops imx_rpmsg_pcm_pm_ops = {
815 	SET_RUNTIME_PM_OPS(imx_rpmsg_pcm_runtime_suspend,
816 			   imx_rpmsg_pcm_runtime_resume,
817 			   NULL)
818 	SET_SYSTEM_SLEEP_PM_OPS(imx_rpmsg_pcm_suspend,
819 				imx_rpmsg_pcm_resume)
820 };
821 
822 static struct platform_driver imx_pcm_rpmsg_driver = {
823 	.probe  = imx_rpmsg_pcm_probe,
824 	.remove	= imx_rpmsg_pcm_remove,
825 	.driver = {
826 		.name = IMX_PCM_DRV_NAME,
827 		.pm = &imx_rpmsg_pcm_pm_ops,
828 	},
829 };
830 module_platform_driver(imx_pcm_rpmsg_driver);
831 
832 MODULE_DESCRIPTION("Freescale SoC Audio RPMSG PCM interface");
833 MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
834 MODULE_ALIAS("platform:" IMX_PCM_DRV_NAME);
835 MODULE_LICENSE("GPL v2");
836