xref: /linux/sound/soc/fsl/imx-pcm-rpmsg.c (revision 42874e4eb35bdfc54f8514685e50434098ba4f6c)
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_BATCH |
23 		SNDRV_PCM_INFO_MMAP |
24 		SNDRV_PCM_INFO_MMAP_VALID |
25 		SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
26 		SNDRV_PCM_INFO_PAUSE |
27 		SNDRV_PCM_INFO_RESUME,
28 	.buffer_bytes_max = IMX_DEFAULT_DMABUF_SIZE,
29 	.period_bytes_min = 512,
30 	.period_bytes_max = 65536,
31 	.periods_min = 2,
32 	.periods_max = 6000,
33 	.fifo_size = 0,
34 };
35 
36 static int imx_rpmsg_pcm_send_message(struct rpmsg_msg *msg,
37 				      struct rpmsg_info *info)
38 {
39 	struct rpmsg_device *rpdev = info->rpdev;
40 	int ret = 0;
41 
42 	mutex_lock(&info->msg_lock);
43 	if (!rpdev) {
44 		dev_err(info->dev, "rpmsg channel not ready\n");
45 		mutex_unlock(&info->msg_lock);
46 		return -EINVAL;
47 	}
48 
49 	dev_dbg(&rpdev->dev, "send cmd %d\n", msg->s_msg.header.cmd);
50 
51 	if (!(msg->s_msg.header.type == MSG_TYPE_C))
52 		reinit_completion(&info->cmd_complete);
53 
54 	ret = rpmsg_send(rpdev->ept, (void *)&msg->s_msg,
55 			 sizeof(struct rpmsg_s_msg));
56 	if (ret) {
57 		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
58 		mutex_unlock(&info->msg_lock);
59 		return ret;
60 	}
61 
62 	/* No receive msg for TYPE_C command */
63 	if (msg->s_msg.header.type == MSG_TYPE_C) {
64 		mutex_unlock(&info->msg_lock);
65 		return 0;
66 	}
67 
68 	/* wait response from rpmsg */
69 	ret = wait_for_completion_timeout(&info->cmd_complete,
70 					  msecs_to_jiffies(RPMSG_TIMEOUT));
71 	if (!ret) {
72 		dev_err(&rpdev->dev, "rpmsg_send cmd %d timeout!\n",
73 			msg->s_msg.header.cmd);
74 		mutex_unlock(&info->msg_lock);
75 		return -ETIMEDOUT;
76 	}
77 
78 	memcpy(&msg->r_msg, &info->r_msg, sizeof(struct rpmsg_r_msg));
79 	memcpy(&info->msg[msg->r_msg.header.cmd].r_msg,
80 	       &msg->r_msg, sizeof(struct rpmsg_r_msg));
81 
82 	/*
83 	 * Reset the buffer pointer to be zero, actully we have
84 	 * set the buffer pointer to be zero in imx_rpmsg_terminate_all
85 	 * But if there is timer task queued in queue, after it is
86 	 * executed the buffer pointer will be changed, so need to
87 	 * reset it again with TERMINATE command.
88 	 */
89 	switch (msg->s_msg.header.cmd) {
90 	case TX_TERMINATE:
91 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
92 		break;
93 	case RX_TERMINATE:
94 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
95 		break;
96 	default:
97 		break;
98 	}
99 
100 	dev_dbg(&rpdev->dev, "cmd:%d, resp %d\n", msg->s_msg.header.cmd,
101 		info->r_msg.param.resp);
102 
103 	mutex_unlock(&info->msg_lock);
104 
105 	return 0;
106 }
107 
108 static int imx_rpmsg_insert_workqueue(struct snd_pcm_substream *substream,
109 				      struct rpmsg_msg *msg,
110 				      struct rpmsg_info *info)
111 {
112 	unsigned long flags;
113 	int ret = 0;
114 
115 	/*
116 	 * Queue the work to workqueue.
117 	 * If the queue is full, drop the message.
118 	 */
119 	spin_lock_irqsave(&info->wq_lock, flags);
120 	if (info->work_write_index != info->work_read_index) {
121 		int index = info->work_write_index;
122 
123 		memcpy(&info->work_list[index].msg, msg,
124 		       sizeof(struct rpmsg_s_msg));
125 
126 		queue_work(info->rpmsg_wq, &info->work_list[index].work);
127 		info->work_write_index++;
128 		info->work_write_index %= WORK_MAX_NUM;
129 	} else {
130 		info->msg_drop_count[substream->stream]++;
131 		ret = -EPIPE;
132 	}
133 	spin_unlock_irqrestore(&info->wq_lock, flags);
134 
135 	return ret;
136 }
137 
138 static int imx_rpmsg_pcm_hw_params(struct snd_soc_component *component,
139 				   struct snd_pcm_substream *substream,
140 				   struct snd_pcm_hw_params *params)
141 {
142 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
143 	struct rpmsg_msg *msg;
144 
145 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
146 		msg = &info->msg[TX_HW_PARAM];
147 		msg->s_msg.header.cmd = TX_HW_PARAM;
148 	} else {
149 		msg = &info->msg[RX_HW_PARAM];
150 		msg->s_msg.header.cmd = RX_HW_PARAM;
151 	}
152 
153 	msg->s_msg.param.rate = params_rate(params);
154 
155 	switch (params_format(params)) {
156 	case SNDRV_PCM_FORMAT_S16_LE:
157 		msg->s_msg.param.format   = RPMSG_S16_LE;
158 		break;
159 	case SNDRV_PCM_FORMAT_S24_LE:
160 		msg->s_msg.param.format   = RPMSG_S24_LE;
161 		break;
162 	case SNDRV_PCM_FORMAT_DSD_U16_LE:
163 		msg->s_msg.param.format   = RPMSG_DSD_U16_LE;
164 		break;
165 	case SNDRV_PCM_FORMAT_DSD_U32_LE:
166 		msg->s_msg.param.format   = RPMSG_DSD_U32_LE;
167 		break;
168 	default:
169 		msg->s_msg.param.format   = RPMSG_S32_LE;
170 		break;
171 	}
172 
173 	switch (params_channels(params)) {
174 	case 1:
175 		msg->s_msg.param.channels = RPMSG_CH_LEFT;
176 		break;
177 	case 2:
178 		msg->s_msg.param.channels = RPMSG_CH_STEREO;
179 		break;
180 	default:
181 		msg->s_msg.param.channels = params_channels(params);
182 		break;
183 	}
184 
185 	info->send_message(msg, info);
186 
187 	return 0;
188 }
189 
190 static snd_pcm_uframes_t imx_rpmsg_pcm_pointer(struct snd_soc_component *component,
191 					       struct snd_pcm_substream *substream)
192 {
193 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
194 	struct rpmsg_msg *msg;
195 	unsigned int pos = 0;
196 	int buffer_tail = 0;
197 
198 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
199 		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
200 	else
201 		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
202 
203 	buffer_tail = msg->r_msg.param.buffer_tail;
204 	pos = buffer_tail * snd_pcm_lib_period_bytes(substream);
205 
206 	return bytes_to_frames(substream->runtime, pos);
207 }
208 
209 static void imx_rpmsg_timer_callback(struct timer_list *t)
210 {
211 	struct stream_timer  *stream_timer =
212 			from_timer(stream_timer, t, timer);
213 	struct snd_pcm_substream *substream = stream_timer->substream;
214 	struct rpmsg_info *info = stream_timer->info;
215 	struct rpmsg_msg *msg;
216 
217 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
218 		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
219 		msg->s_msg.header.cmd = TX_PERIOD_DONE;
220 	} else {
221 		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
222 		msg->s_msg.header.cmd = RX_PERIOD_DONE;
223 	}
224 
225 	imx_rpmsg_insert_workqueue(substream, msg, info);
226 }
227 
228 static int imx_rpmsg_pcm_open(struct snd_soc_component *component,
229 			      struct snd_pcm_substream *substream)
230 {
231 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
232 	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
233 	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
234 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
235 	struct snd_pcm_hardware pcm_hardware;
236 	struct rpmsg_msg *msg;
237 	int ret = 0;
238 	int cmd;
239 
240 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
241 		msg = &info->msg[TX_OPEN];
242 		msg->s_msg.header.cmd = TX_OPEN;
243 
244 		/* reinitialize buffer counter*/
245 		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
246 		info->msg[cmd].s_msg.param.buffer_tail = 0;
247 		info->msg[cmd].r_msg.param.buffer_tail = 0;
248 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
249 
250 	} else {
251 		msg = &info->msg[RX_OPEN];
252 		msg->s_msg.header.cmd = RX_OPEN;
253 
254 		/* reinitialize buffer counter*/
255 		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
256 		info->msg[cmd].s_msg.param.buffer_tail = 0;
257 		info->msg[cmd].r_msg.param.buffer_tail = 0;
258 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
259 	}
260 
261 	info->send_message(msg, info);
262 
263 	pcm_hardware = imx_rpmsg_pcm_hardware;
264 	pcm_hardware.buffer_bytes_max = rpmsg->buffer_size;
265 	pcm_hardware.period_bytes_max = pcm_hardware.buffer_bytes_max / 2;
266 
267 	snd_soc_set_runtime_hwparams(substream, &pcm_hardware);
268 
269 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
270 					    SNDRV_PCM_HW_PARAM_PERIODS);
271 	if (ret < 0)
272 		return ret;
273 
274 	info->msg_drop_count[substream->stream] = 0;
275 
276 	/* Create timer*/
277 	info->stream_timer[substream->stream].info = info;
278 	info->stream_timer[substream->stream].substream = substream;
279 	timer_setup(&info->stream_timer[substream->stream].timer,
280 		    imx_rpmsg_timer_callback, 0);
281 	return ret;
282 }
283 
284 static int imx_rpmsg_pcm_close(struct snd_soc_component *component,
285 			       struct snd_pcm_substream *substream)
286 {
287 	struct snd_soc_pcm_runtime *rtd = snd_soc_substream_to_rtd(substream);
288 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
289 	struct rpmsg_msg *msg;
290 
291 	/* Flush work in workqueue to make TX_CLOSE is the last message */
292 	flush_workqueue(info->rpmsg_wq);
293 
294 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
295 		msg = &info->msg[TX_CLOSE];
296 		msg->s_msg.header.cmd = TX_CLOSE;
297 	} else {
298 		msg = &info->msg[RX_CLOSE];
299 		msg->s_msg.header.cmd = RX_CLOSE;
300 	}
301 
302 	info->send_message(msg, info);
303 
304 	del_timer(&info->stream_timer[substream->stream].timer);
305 
306 	rtd->dai_link->ignore_suspend = 0;
307 
308 	if (info->msg_drop_count[substream->stream])
309 		dev_warn(rtd->dev, "Msg is dropped!, number is %d\n",
310 			 info->msg_drop_count[substream->stream]);
311 
312 	return 0;
313 }
314 
315 static int imx_rpmsg_pcm_prepare(struct snd_soc_component *component,
316 				 struct snd_pcm_substream *substream)
317 {
318 	struct snd_pcm_runtime *runtime = substream->runtime;
319 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
320 	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
321 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
322 
323 	/*
324 	 * NON-MMAP mode, NONBLOCK, Version 2, enable lpa in dts
325 	 * four conditions to determine the lpa is enabled.
326 	 */
327 	if ((runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
328 	     runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) &&
329 	     rpmsg->enable_lpa) {
330 		/*
331 		 * Ignore suspend operation in low power mode
332 		 * M core will continue playback music on A core suspend.
333 		 */
334 		rtd->dai_link->ignore_suspend = 1;
335 		rpmsg->force_lpa = 1;
336 	} else {
337 		rpmsg->force_lpa = 0;
338 	}
339 
340 	return 0;
341 }
342 
343 static void imx_rpmsg_pcm_dma_complete(void *arg)
344 {
345 	struct snd_pcm_substream *substream = arg;
346 
347 	snd_pcm_period_elapsed(substream);
348 }
349 
350 static int imx_rpmsg_prepare_and_submit(struct snd_soc_component *component,
351 					struct snd_pcm_substream *substream)
352 {
353 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
354 	struct rpmsg_msg *msg;
355 
356 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
357 		msg = &info->msg[TX_BUFFER];
358 		msg->s_msg.header.cmd = TX_BUFFER;
359 	} else {
360 		msg = &info->msg[RX_BUFFER];
361 		msg->s_msg.header.cmd = RX_BUFFER;
362 	}
363 
364 	/* Send buffer address and buffer size */
365 	msg->s_msg.param.buffer_addr = substream->runtime->dma_addr;
366 	msg->s_msg.param.buffer_size = snd_pcm_lib_buffer_bytes(substream);
367 	msg->s_msg.param.period_size = snd_pcm_lib_period_bytes(substream);
368 	msg->s_msg.param.buffer_tail = 0;
369 
370 	info->num_period[substream->stream] = msg->s_msg.param.buffer_size /
371 					      msg->s_msg.param.period_size;
372 
373 	info->callback[substream->stream] = imx_rpmsg_pcm_dma_complete;
374 	info->callback_param[substream->stream] = substream;
375 
376 	return imx_rpmsg_insert_workqueue(substream, msg, info);
377 }
378 
379 static int imx_rpmsg_async_issue_pending(struct snd_soc_component *component,
380 					 struct snd_pcm_substream *substream)
381 {
382 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
383 	struct rpmsg_msg *msg;
384 
385 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
386 		msg = &info->msg[TX_START];
387 		msg->s_msg.header.cmd = TX_START;
388 	} else {
389 		msg = &info->msg[RX_START];
390 		msg->s_msg.header.cmd = RX_START;
391 	}
392 
393 	return imx_rpmsg_insert_workqueue(substream, msg, info);
394 }
395 
396 static int imx_rpmsg_restart(struct snd_soc_component *component,
397 			     struct snd_pcm_substream *substream)
398 {
399 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
400 	struct rpmsg_msg *msg;
401 
402 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
403 		msg = &info->msg[TX_RESTART];
404 		msg->s_msg.header.cmd = TX_RESTART;
405 	} else {
406 		msg = &info->msg[RX_RESTART];
407 		msg->s_msg.header.cmd = RX_RESTART;
408 	}
409 
410 	return imx_rpmsg_insert_workqueue(substream, msg, info);
411 }
412 
413 static int imx_rpmsg_pause(struct snd_soc_component *component,
414 			   struct snd_pcm_substream *substream)
415 {
416 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
417 	struct rpmsg_msg *msg;
418 
419 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
420 		msg = &info->msg[TX_PAUSE];
421 		msg->s_msg.header.cmd = TX_PAUSE;
422 	} else {
423 		msg = &info->msg[RX_PAUSE];
424 		msg->s_msg.header.cmd = RX_PAUSE;
425 	}
426 
427 	return imx_rpmsg_insert_workqueue(substream, msg, info);
428 }
429 
430 static int imx_rpmsg_terminate_all(struct snd_soc_component *component,
431 				   struct snd_pcm_substream *substream)
432 {
433 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
434 	struct rpmsg_msg *msg;
435 	int cmd;
436 
437 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
438 		msg = &info->msg[TX_TERMINATE];
439 		msg->s_msg.header.cmd = TX_TERMINATE;
440 		/* Clear buffer count*/
441 		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
442 		info->msg[cmd].s_msg.param.buffer_tail = 0;
443 		info->msg[cmd].r_msg.param.buffer_tail = 0;
444 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
445 	} else {
446 		msg = &info->msg[RX_TERMINATE];
447 		msg->s_msg.header.cmd = RX_TERMINATE;
448 		/* Clear buffer count*/
449 		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
450 		info->msg[cmd].s_msg.param.buffer_tail = 0;
451 		info->msg[cmd].r_msg.param.buffer_tail = 0;
452 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
453 	}
454 
455 	del_timer(&info->stream_timer[substream->stream].timer);
456 
457 	return imx_rpmsg_insert_workqueue(substream, msg, info);
458 }
459 
460 static int imx_rpmsg_pcm_trigger(struct snd_soc_component *component,
461 				 struct snd_pcm_substream *substream, int cmd)
462 {
463 	struct snd_pcm_runtime *runtime = substream->runtime;
464 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
465 	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
466 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
467 	int ret = 0;
468 
469 	switch (cmd) {
470 	case SNDRV_PCM_TRIGGER_START:
471 		ret = imx_rpmsg_prepare_and_submit(component, substream);
472 		if (ret)
473 			return ret;
474 		ret = imx_rpmsg_async_issue_pending(component, substream);
475 		break;
476 	case SNDRV_PCM_TRIGGER_RESUME:
477 		if (rpmsg->force_lpa)
478 			break;
479 		fallthrough;
480 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
481 		ret = imx_rpmsg_restart(component, substream);
482 		break;
483 	case SNDRV_PCM_TRIGGER_SUSPEND:
484 		if (!rpmsg->force_lpa) {
485 			if (runtime->info & SNDRV_PCM_INFO_PAUSE)
486 				ret = imx_rpmsg_pause(component, substream);
487 			else
488 				ret = imx_rpmsg_terminate_all(component, substream);
489 		}
490 		break;
491 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
492 		ret = imx_rpmsg_pause(component, substream);
493 		break;
494 	case SNDRV_PCM_TRIGGER_STOP:
495 		ret = imx_rpmsg_terminate_all(component, substream);
496 		break;
497 	default:
498 		return -EINVAL;
499 	}
500 
501 	if (ret)
502 		return ret;
503 
504 	return 0;
505 }
506 
507 /*
508  * imx_rpmsg_pcm_ack
509  *
510  * Send the period index to M core through rpmsg, but not send
511  * all the period index to M core, reduce some unnessesary msg
512  * to reduce the pressure of rpmsg bandwidth.
513  */
514 static int imx_rpmsg_pcm_ack(struct snd_soc_component *component,
515 			     struct snd_pcm_substream *substream)
516 {
517 	struct snd_pcm_runtime *runtime = substream->runtime;
518 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
519 	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
520 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
521 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
522 	snd_pcm_uframes_t period_size = runtime->period_size;
523 	snd_pcm_sframes_t avail;
524 	struct timer_list *timer;
525 	struct rpmsg_msg *msg;
526 	unsigned long flags;
527 	int buffer_tail = 0;
528 	int written_num;
529 
530 	if (!rpmsg->force_lpa)
531 		return 0;
532 
533 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
534 		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
535 		msg->s_msg.header.cmd = TX_PERIOD_DONE;
536 	} else {
537 		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
538 		msg->s_msg.header.cmd = RX_PERIOD_DONE;
539 	}
540 
541 	msg->s_msg.header.type = MSG_TYPE_C;
542 
543 	buffer_tail = (frames_to_bytes(runtime, runtime->control->appl_ptr) %
544 		       snd_pcm_lib_buffer_bytes(substream));
545 	buffer_tail = buffer_tail / snd_pcm_lib_period_bytes(substream);
546 
547 	/* There is update for period index */
548 	if (buffer_tail != msg->s_msg.param.buffer_tail) {
549 		written_num = buffer_tail - msg->s_msg.param.buffer_tail;
550 		if (written_num < 0)
551 			written_num += runtime->periods;
552 
553 		msg->s_msg.param.buffer_tail = buffer_tail;
554 
555 		/* The notification message is updated to latest */
556 		spin_lock_irqsave(&info->lock[substream->stream], flags);
557 		memcpy(&info->notify[substream->stream], msg,
558 		       sizeof(struct rpmsg_s_msg));
559 		info->notify_updated[substream->stream] = true;
560 		spin_unlock_irqrestore(&info->lock[substream->stream], flags);
561 
562 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
563 			avail = snd_pcm_playback_hw_avail(runtime);
564 		else
565 			avail = snd_pcm_capture_hw_avail(runtime);
566 
567 		timer = &info->stream_timer[substream->stream].timer;
568 		/*
569 		 * If the data in the buffer is less than one period before
570 		 * this fill, which means the data may not enough on M
571 		 * core side, we need to send message immediately to let
572 		 * M core know the pointer is updated.
573 		 * if there is more than one period data in the buffer before
574 		 * this fill, which means the data is enough on M core side,
575 		 * we can delay one period (using timer) to send the message
576 		 * for reduce the message number in workqueue, because the
577 		 * pointer may be updated by ack function later, we can
578 		 * send latest pointer to M core side.
579 		 */
580 		if ((avail - written_num * period_size) <= period_size) {
581 			imx_rpmsg_insert_workqueue(substream, msg, info);
582 		} else if (rpmsg->force_lpa && !timer_pending(timer)) {
583 			int time_msec;
584 
585 			time_msec = (int)(runtime->period_size * 1000 / runtime->rate);
586 			mod_timer(timer, jiffies + msecs_to_jiffies(time_msec));
587 		}
588 	}
589 
590 	return 0;
591 }
592 
593 static int imx_rpmsg_pcm_new(struct snd_soc_component *component,
594 			     struct snd_soc_pcm_runtime *rtd)
595 {
596 	struct snd_card *card = rtd->card->snd_card;
597 	struct snd_pcm *pcm = rtd->pcm;
598 	struct snd_soc_dai *cpu_dai = snd_soc_rtd_to_cpu(rtd, 0);
599 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
600 	int ret;
601 
602 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
603 	if (ret)
604 		return ret;
605 
606 	return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_WC,
607 					    pcm->card->dev, rpmsg->buffer_size);
608 }
609 
610 static const struct snd_soc_component_driver imx_rpmsg_soc_component = {
611 	.name		= IMX_PCM_DRV_NAME,
612 	.pcm_construct	= imx_rpmsg_pcm_new,
613 	.open		= imx_rpmsg_pcm_open,
614 	.close		= imx_rpmsg_pcm_close,
615 	.hw_params	= imx_rpmsg_pcm_hw_params,
616 	.trigger	= imx_rpmsg_pcm_trigger,
617 	.pointer	= imx_rpmsg_pcm_pointer,
618 	.ack		= imx_rpmsg_pcm_ack,
619 	.prepare	= imx_rpmsg_pcm_prepare,
620 };
621 
622 static void imx_rpmsg_pcm_work(struct work_struct *work)
623 {
624 	struct work_of_rpmsg *work_of_rpmsg;
625 	bool is_notification = false;
626 	struct rpmsg_info *info;
627 	struct rpmsg_msg msg;
628 	unsigned long flags;
629 
630 	work_of_rpmsg = container_of(work, struct work_of_rpmsg, work);
631 	info = work_of_rpmsg->info;
632 
633 	/*
634 	 * Every work in the work queue, first we check if there
635 	 * is update for period is filled, because there may be not
636 	 * enough data in M core side, need to let M core know
637 	 * data is updated immediately.
638 	 */
639 	spin_lock_irqsave(&info->lock[TX], flags);
640 	if (info->notify_updated[TX]) {
641 		memcpy(&msg, &info->notify[TX], sizeof(struct rpmsg_s_msg));
642 		info->notify_updated[TX] = false;
643 		spin_unlock_irqrestore(&info->lock[TX], flags);
644 		info->send_message(&msg, info);
645 	} else {
646 		spin_unlock_irqrestore(&info->lock[TX], flags);
647 	}
648 
649 	spin_lock_irqsave(&info->lock[RX], flags);
650 	if (info->notify_updated[RX]) {
651 		memcpy(&msg, &info->notify[RX], sizeof(struct rpmsg_s_msg));
652 		info->notify_updated[RX] = false;
653 		spin_unlock_irqrestore(&info->lock[RX], flags);
654 		info->send_message(&msg, info);
655 	} else {
656 		spin_unlock_irqrestore(&info->lock[RX], flags);
657 	}
658 
659 	/* Skip the notification message for it has been processed above */
660 	if (work_of_rpmsg->msg.s_msg.header.type == MSG_TYPE_C &&
661 	    (work_of_rpmsg->msg.s_msg.header.cmd == TX_PERIOD_DONE ||
662 	     work_of_rpmsg->msg.s_msg.header.cmd == RX_PERIOD_DONE))
663 		is_notification = true;
664 
665 	if (!is_notification)
666 		info->send_message(&work_of_rpmsg->msg, info);
667 
668 	/* update read index */
669 	spin_lock_irqsave(&info->wq_lock, flags);
670 	info->work_read_index++;
671 	info->work_read_index %= WORK_MAX_NUM;
672 	spin_unlock_irqrestore(&info->wq_lock, flags);
673 }
674 
675 static int imx_rpmsg_pcm_probe(struct platform_device *pdev)
676 {
677 	struct snd_soc_component *component;
678 	struct rpmsg_info *info;
679 	int ret, i;
680 
681 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
682 	if (!info)
683 		return -ENOMEM;
684 
685 	platform_set_drvdata(pdev, info);
686 
687 	info->rpdev = container_of(pdev->dev.parent, struct rpmsg_device, dev);
688 	info->dev = &pdev->dev;
689 	/* Setup work queue */
690 	info->rpmsg_wq = alloc_ordered_workqueue(info->rpdev->id.name,
691 						 WQ_HIGHPRI |
692 						 WQ_UNBOUND |
693 						 WQ_FREEZABLE);
694 	if (!info->rpmsg_wq) {
695 		dev_err(&pdev->dev, "workqueue create failed\n");
696 		return -ENOMEM;
697 	}
698 
699 	/* Write index initialize 1, make it differ with the read index */
700 	info->work_write_index = 1;
701 	info->send_message = imx_rpmsg_pcm_send_message;
702 
703 	for (i = 0; i < WORK_MAX_NUM; i++) {
704 		INIT_WORK(&info->work_list[i].work, imx_rpmsg_pcm_work);
705 		info->work_list[i].info = info;
706 	}
707 
708 	/* Initialize msg */
709 	for (i = 0; i < MSG_MAX_NUM; i++) {
710 		info->msg[i].s_msg.header.cate  = IMX_RPMSG_AUDIO;
711 		info->msg[i].s_msg.header.major = IMX_RMPSG_MAJOR;
712 		info->msg[i].s_msg.header.minor = IMX_RMPSG_MINOR;
713 		info->msg[i].s_msg.header.type  = MSG_TYPE_A;
714 		info->msg[i].s_msg.param.audioindex = 0;
715 	}
716 
717 	init_completion(&info->cmd_complete);
718 	mutex_init(&info->msg_lock);
719 	spin_lock_init(&info->lock[TX]);
720 	spin_lock_init(&info->lock[RX]);
721 	spin_lock_init(&info->wq_lock);
722 
723 	ret = devm_snd_soc_register_component(&pdev->dev,
724 					      &imx_rpmsg_soc_component,
725 					      NULL, 0);
726 	if (ret)
727 		goto fail;
728 
729 	component = snd_soc_lookup_component(&pdev->dev, NULL);
730 	if (!component) {
731 		ret = -EINVAL;
732 		goto fail;
733 	}
734 
735 	/* platform component name is used by machine driver to link with */
736 	component->name = info->rpdev->id.name;
737 
738 #ifdef CONFIG_DEBUG_FS
739 	component->debugfs_prefix = "rpmsg";
740 #endif
741 
742 	return 0;
743 
744 fail:
745 	if (info->rpmsg_wq)
746 		destroy_workqueue(info->rpmsg_wq);
747 
748 	return ret;
749 }
750 
751 static void imx_rpmsg_pcm_remove(struct platform_device *pdev)
752 {
753 	struct rpmsg_info *info = platform_get_drvdata(pdev);
754 
755 	if (info->rpmsg_wq)
756 		destroy_workqueue(info->rpmsg_wq);
757 }
758 
759 #ifdef CONFIG_PM
760 static int imx_rpmsg_pcm_runtime_resume(struct device *dev)
761 {
762 	struct rpmsg_info *info = dev_get_drvdata(dev);
763 
764 	cpu_latency_qos_add_request(&info->pm_qos_req, 0);
765 
766 	return 0;
767 }
768 
769 static int imx_rpmsg_pcm_runtime_suspend(struct device *dev)
770 {
771 	struct rpmsg_info *info = dev_get_drvdata(dev);
772 
773 	cpu_latency_qos_remove_request(&info->pm_qos_req);
774 
775 	return 0;
776 }
777 #endif
778 
779 #ifdef CONFIG_PM_SLEEP
780 static int imx_rpmsg_pcm_suspend(struct device *dev)
781 {
782 	struct rpmsg_info *info = dev_get_drvdata(dev);
783 	struct rpmsg_msg *rpmsg_tx;
784 	struct rpmsg_msg *rpmsg_rx;
785 
786 	rpmsg_tx = &info->msg[TX_SUSPEND];
787 	rpmsg_rx = &info->msg[RX_SUSPEND];
788 
789 	rpmsg_tx->s_msg.header.cmd = TX_SUSPEND;
790 	info->send_message(rpmsg_tx, info);
791 
792 	rpmsg_rx->s_msg.header.cmd = RX_SUSPEND;
793 	info->send_message(rpmsg_rx, info);
794 
795 	return 0;
796 }
797 
798 static int imx_rpmsg_pcm_resume(struct device *dev)
799 {
800 	struct rpmsg_info *info = dev_get_drvdata(dev);
801 	struct rpmsg_msg *rpmsg_tx;
802 	struct rpmsg_msg *rpmsg_rx;
803 
804 	rpmsg_tx = &info->msg[TX_RESUME];
805 	rpmsg_rx = &info->msg[RX_RESUME];
806 
807 	rpmsg_tx->s_msg.header.cmd = TX_RESUME;
808 	info->send_message(rpmsg_tx, info);
809 
810 	rpmsg_rx->s_msg.header.cmd = RX_RESUME;
811 	info->send_message(rpmsg_rx, info);
812 
813 	return 0;
814 }
815 #endif /* CONFIG_PM_SLEEP */
816 
817 static const struct dev_pm_ops imx_rpmsg_pcm_pm_ops = {
818 	SET_RUNTIME_PM_OPS(imx_rpmsg_pcm_runtime_suspend,
819 			   imx_rpmsg_pcm_runtime_resume,
820 			   NULL)
821 	SET_SYSTEM_SLEEP_PM_OPS(imx_rpmsg_pcm_suspend,
822 				imx_rpmsg_pcm_resume)
823 };
824 
825 static struct platform_driver imx_pcm_rpmsg_driver = {
826 	.probe  = imx_rpmsg_pcm_probe,
827 	.remove_new = imx_rpmsg_pcm_remove,
828 	.driver = {
829 		.name = IMX_PCM_DRV_NAME,
830 		.pm = &imx_rpmsg_pcm_pm_ops,
831 	},
832 };
833 module_platform_driver(imx_pcm_rpmsg_driver);
834 
835 MODULE_DESCRIPTION("Freescale SoC Audio RPMSG PCM interface");
836 MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
837 MODULE_ALIAS("platform:" IMX_PCM_DRV_NAME);
838 MODULE_LICENSE("GPL v2");
839