xref: /openbmc/linux/sound/soc/fsl/imx-pcm-rpmsg.c (revision 27e45f2e)
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 	int ret = 0;
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 ret;
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 rpmsg_msg *msg;
233 	int ret = 0;
234 	int cmd;
235 
236 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
237 		msg = &info->msg[TX_OPEN];
238 		msg->s_msg.header.cmd = TX_OPEN;
239 
240 		/* reinitialize buffer counter*/
241 		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
242 		info->msg[cmd].s_msg.param.buffer_tail = 0;
243 		info->msg[cmd].r_msg.param.buffer_tail = 0;
244 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
245 
246 	} else {
247 		msg = &info->msg[RX_OPEN];
248 		msg->s_msg.header.cmd = RX_OPEN;
249 
250 		/* reinitialize buffer counter*/
251 		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
252 		info->msg[cmd].s_msg.param.buffer_tail = 0;
253 		info->msg[cmd].r_msg.param.buffer_tail = 0;
254 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
255 	}
256 
257 	info->send_message(msg, info);
258 
259 	imx_rpmsg_pcm_hardware.period_bytes_max =
260 			imx_rpmsg_pcm_hardware.buffer_bytes_max / 2;
261 
262 	snd_soc_set_runtime_hwparams(substream, &imx_rpmsg_pcm_hardware);
263 
264 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
265 					    SNDRV_PCM_HW_PARAM_PERIODS);
266 	if (ret < 0)
267 		return ret;
268 
269 	info->msg_drop_count[substream->stream] = 0;
270 
271 	/* Create timer*/
272 	info->stream_timer[substream->stream].info = info;
273 	info->stream_timer[substream->stream].substream = substream;
274 	timer_setup(&info->stream_timer[substream->stream].timer,
275 		    imx_rpmsg_timer_callback, 0);
276 	return ret;
277 }
278 
279 static int imx_rpmsg_pcm_close(struct snd_soc_component *component,
280 			       struct snd_pcm_substream *substream)
281 {
282 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
283 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
284 	struct rpmsg_msg *msg;
285 	int ret = 0;
286 
287 	/* Flush work in workqueue to make TX_CLOSE is the last message */
288 	flush_workqueue(info->rpmsg_wq);
289 
290 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
291 		msg = &info->msg[TX_CLOSE];
292 		msg->s_msg.header.cmd = TX_CLOSE;
293 	} else {
294 		msg = &info->msg[RX_CLOSE];
295 		msg->s_msg.header.cmd = RX_CLOSE;
296 	}
297 
298 	info->send_message(msg, info);
299 
300 	del_timer(&info->stream_timer[substream->stream].timer);
301 
302 	rtd->dai_link->ignore_suspend = 0;
303 
304 	if (info->msg_drop_count[substream->stream])
305 		dev_warn(rtd->dev, "Msg is dropped!, number is %d\n",
306 			 info->msg_drop_count[substream->stream]);
307 
308 	return ret;
309 }
310 
311 static int imx_rpmsg_pcm_prepare(struct snd_soc_component *component,
312 				 struct snd_pcm_substream *substream)
313 {
314 	struct snd_pcm_runtime *runtime = substream->runtime;
315 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
316 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
317 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
318 
319 	/*
320 	 * NON-MMAP mode, NONBLOCK, Version 2, enable lpa in dts
321 	 * four conditions to determine the lpa is enabled.
322 	 */
323 	if ((runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
324 	     runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) &&
325 	     rpmsg->enable_lpa) {
326 		/*
327 		 * Ignore suspend operation in low power mode
328 		 * M core will continue playback music on A core suspend.
329 		 */
330 		rtd->dai_link->ignore_suspend = 1;
331 		rpmsg->force_lpa = 1;
332 	} else {
333 		rpmsg->force_lpa = 0;
334 	}
335 
336 	return 0;
337 }
338 
339 static void imx_rpmsg_pcm_dma_complete(void *arg)
340 {
341 	struct snd_pcm_substream *substream = arg;
342 
343 	snd_pcm_period_elapsed(substream);
344 }
345 
346 static int imx_rpmsg_prepare_and_submit(struct snd_soc_component *component,
347 					struct snd_pcm_substream *substream)
348 {
349 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
350 	struct rpmsg_msg *msg;
351 
352 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
353 		msg = &info->msg[TX_BUFFER];
354 		msg->s_msg.header.cmd = TX_BUFFER;
355 	} else {
356 		msg = &info->msg[RX_BUFFER];
357 		msg->s_msg.header.cmd = RX_BUFFER;
358 	}
359 
360 	/* Send buffer address and buffer size */
361 	msg->s_msg.param.buffer_addr = substream->runtime->dma_addr;
362 	msg->s_msg.param.buffer_size = snd_pcm_lib_buffer_bytes(substream);
363 	msg->s_msg.param.period_size = snd_pcm_lib_period_bytes(substream);
364 	msg->s_msg.param.buffer_tail = 0;
365 
366 	info->num_period[substream->stream] = msg->s_msg.param.buffer_size /
367 					      msg->s_msg.param.period_size;
368 
369 	info->callback[substream->stream] = imx_rpmsg_pcm_dma_complete;
370 	info->callback_param[substream->stream] = substream;
371 
372 	return imx_rpmsg_insert_workqueue(substream, msg, info);
373 }
374 
375 static int imx_rpmsg_async_issue_pending(struct snd_soc_component *component,
376 					 struct snd_pcm_substream *substream)
377 {
378 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
379 	struct rpmsg_msg *msg;
380 
381 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
382 		msg = &info->msg[TX_START];
383 		msg->s_msg.header.cmd = TX_START;
384 	} else {
385 		msg = &info->msg[RX_START];
386 		msg->s_msg.header.cmd = RX_START;
387 	}
388 
389 	return imx_rpmsg_insert_workqueue(substream, msg, info);
390 }
391 
392 static int imx_rpmsg_restart(struct snd_soc_component *component,
393 			     struct snd_pcm_substream *substream)
394 {
395 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
396 	struct rpmsg_msg *msg;
397 
398 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
399 		msg = &info->msg[TX_RESTART];
400 		msg->s_msg.header.cmd = TX_RESTART;
401 	} else {
402 		msg = &info->msg[RX_RESTART];
403 		msg->s_msg.header.cmd = RX_RESTART;
404 	}
405 
406 	return imx_rpmsg_insert_workqueue(substream, msg, info);
407 }
408 
409 static int imx_rpmsg_pause(struct snd_soc_component *component,
410 			   struct snd_pcm_substream *substream)
411 {
412 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
413 	struct rpmsg_msg *msg;
414 
415 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
416 		msg = &info->msg[TX_PAUSE];
417 		msg->s_msg.header.cmd = TX_PAUSE;
418 	} else {
419 		msg = &info->msg[RX_PAUSE];
420 		msg->s_msg.header.cmd = RX_PAUSE;
421 	}
422 
423 	return imx_rpmsg_insert_workqueue(substream, msg, info);
424 }
425 
426 static int imx_rpmsg_terminate_all(struct snd_soc_component *component,
427 				   struct snd_pcm_substream *substream)
428 {
429 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
430 	struct rpmsg_msg *msg;
431 	int cmd;
432 
433 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
434 		msg = &info->msg[TX_TERMINATE];
435 		msg->s_msg.header.cmd = TX_TERMINATE;
436 		/* Clear buffer count*/
437 		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
438 		info->msg[cmd].s_msg.param.buffer_tail = 0;
439 		info->msg[cmd].r_msg.param.buffer_tail = 0;
440 		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
441 	} else {
442 		msg = &info->msg[RX_TERMINATE];
443 		msg->s_msg.header.cmd = RX_TERMINATE;
444 		/* Clear buffer count*/
445 		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
446 		info->msg[cmd].s_msg.param.buffer_tail = 0;
447 		info->msg[cmd].r_msg.param.buffer_tail = 0;
448 		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
449 	}
450 
451 	del_timer(&info->stream_timer[substream->stream].timer);
452 
453 	return imx_rpmsg_insert_workqueue(substream, msg, info);
454 }
455 
456 static int imx_rpmsg_pcm_trigger(struct snd_soc_component *component,
457 				 struct snd_pcm_substream *substream, int cmd)
458 {
459 	struct snd_pcm_runtime *runtime = substream->runtime;
460 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
461 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
462 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
463 	int ret = 0;
464 
465 	switch (cmd) {
466 	case SNDRV_PCM_TRIGGER_START:
467 		ret = imx_rpmsg_prepare_and_submit(component, substream);
468 		if (ret)
469 			return ret;
470 		ret = imx_rpmsg_async_issue_pending(component, substream);
471 		break;
472 	case SNDRV_PCM_TRIGGER_RESUME:
473 		if (rpmsg->force_lpa)
474 			break;
475 		fallthrough;
476 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
477 		ret = imx_rpmsg_restart(component, substream);
478 		break;
479 	case SNDRV_PCM_TRIGGER_SUSPEND:
480 		if (!rpmsg->force_lpa) {
481 			if (runtime->info & SNDRV_PCM_INFO_PAUSE)
482 				ret = imx_rpmsg_pause(component, substream);
483 			else
484 				ret = imx_rpmsg_terminate_all(component, substream);
485 		}
486 		break;
487 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
488 		ret = imx_rpmsg_pause(component, substream);
489 		break;
490 	case SNDRV_PCM_TRIGGER_STOP:
491 		ret = imx_rpmsg_terminate_all(component, substream);
492 		break;
493 	default:
494 		return -EINVAL;
495 	}
496 
497 	if (ret)
498 		return ret;
499 
500 	return 0;
501 }
502 
503 /*
504  * imx_rpmsg_pcm_ack
505  *
506  * Send the period index to M core through rpmsg, but not send
507  * all the period index to M core, reduce some unnessesary msg
508  * to reduce the pressure of rpmsg bandwidth.
509  */
510 static int imx_rpmsg_pcm_ack(struct snd_soc_component *component,
511 			     struct snd_pcm_substream *substream)
512 {
513 	struct snd_pcm_runtime *runtime = substream->runtime;
514 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
515 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
516 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
517 	struct rpmsg_info *info = dev_get_drvdata(component->dev);
518 	snd_pcm_uframes_t period_size = runtime->period_size;
519 	snd_pcm_sframes_t avail;
520 	struct timer_list *timer;
521 	struct rpmsg_msg *msg;
522 	unsigned long flags;
523 	int buffer_tail = 0;
524 	int written_num;
525 
526 	if (!rpmsg->force_lpa)
527 		return 0;
528 
529 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
530 		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
531 		msg->s_msg.header.cmd = TX_PERIOD_DONE;
532 	} else {
533 		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
534 		msg->s_msg.header.cmd = RX_PERIOD_DONE;
535 	}
536 
537 	msg->s_msg.header.type = MSG_TYPE_C;
538 
539 	buffer_tail = (frames_to_bytes(runtime, runtime->control->appl_ptr) %
540 		       snd_pcm_lib_buffer_bytes(substream));
541 	buffer_tail = buffer_tail / snd_pcm_lib_period_bytes(substream);
542 
543 	/* There is update for period index */
544 	if (buffer_tail != msg->s_msg.param.buffer_tail) {
545 		written_num = buffer_tail - msg->s_msg.param.buffer_tail;
546 		if (written_num < 0)
547 			written_num += runtime->periods;
548 
549 		msg->s_msg.param.buffer_tail = buffer_tail;
550 
551 		/* The notification message is updated to latest */
552 		spin_lock_irqsave(&info->lock[substream->stream], flags);
553 		memcpy(&info->notify[substream->stream], msg,
554 		       sizeof(struct rpmsg_s_msg));
555 		info->notify_updated[substream->stream] = true;
556 		spin_unlock_irqrestore(&info->lock[substream->stream], flags);
557 
558 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
559 			avail = snd_pcm_playback_hw_avail(runtime);
560 		else
561 			avail = snd_pcm_capture_hw_avail(runtime);
562 
563 		timer = &info->stream_timer[substream->stream].timer;
564 		/*
565 		 * If the data in the buffer is less than one period before
566 		 * this fill, which means the data may not enough on M
567 		 * core side, we need to send message immediately to let
568 		 * M core know the pointer is updated.
569 		 * if there is more than one period data in the buffer before
570 		 * this fill, which means the data is enough on M core side,
571 		 * we can delay one period (using timer) to send the message
572 		 * for reduce the message number in workqueue, because the
573 		 * pointer may be updated by ack function later, we can
574 		 * send latest pointer to M core side.
575 		 */
576 		if ((avail - written_num * period_size) <= period_size) {
577 			imx_rpmsg_insert_workqueue(substream, msg, info);
578 		} else if (rpmsg->force_lpa && !timer_pending(timer)) {
579 			int time_msec;
580 
581 			time_msec = (int)(runtime->period_size * 1000 / runtime->rate);
582 			mod_timer(timer, jiffies + msecs_to_jiffies(time_msec));
583 		}
584 	}
585 
586 	return 0;
587 }
588 
589 static int imx_rpmsg_pcm_new(struct snd_soc_component *component,
590 			     struct snd_soc_pcm_runtime *rtd)
591 {
592 	struct snd_card *card = rtd->card->snd_card;
593 	struct snd_pcm *pcm = rtd->pcm;
594 	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
595 	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
596 	int ret;
597 
598 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
599 	if (ret)
600 		return ret;
601 
602 	imx_rpmsg_pcm_hardware.buffer_bytes_max = rpmsg->buffer_size;
603 	return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV_WC,
604 					    pcm->card->dev, rpmsg->buffer_size);
605 }
606 
607 static const struct snd_soc_component_driver imx_rpmsg_soc_component = {
608 	.name		= IMX_PCM_DRV_NAME,
609 	.pcm_construct	= imx_rpmsg_pcm_new,
610 	.open		= imx_rpmsg_pcm_open,
611 	.close		= imx_rpmsg_pcm_close,
612 	.hw_params	= imx_rpmsg_pcm_hw_params,
613 	.trigger	= imx_rpmsg_pcm_trigger,
614 	.pointer	= imx_rpmsg_pcm_pointer,
615 	.ack		= imx_rpmsg_pcm_ack,
616 	.prepare	= imx_rpmsg_pcm_prepare,
617 };
618 
619 static void imx_rpmsg_pcm_work(struct work_struct *work)
620 {
621 	struct work_of_rpmsg *work_of_rpmsg;
622 	bool is_notification = false;
623 	struct rpmsg_info *info;
624 	struct rpmsg_msg msg;
625 	unsigned long flags;
626 
627 	work_of_rpmsg = container_of(work, struct work_of_rpmsg, work);
628 	info = work_of_rpmsg->info;
629 
630 	/*
631 	 * Every work in the work queue, first we check if there
632 	 * is update for period is filled, because there may be not
633 	 * enough data in M core side, need to let M core know
634 	 * data is updated immediately.
635 	 */
636 	spin_lock_irqsave(&info->lock[TX], flags);
637 	if (info->notify_updated[TX]) {
638 		memcpy(&msg, &info->notify[TX], sizeof(struct rpmsg_s_msg));
639 		info->notify_updated[TX] = false;
640 		spin_unlock_irqrestore(&info->lock[TX], flags);
641 		info->send_message(&msg, info);
642 	} else {
643 		spin_unlock_irqrestore(&info->lock[TX], flags);
644 	}
645 
646 	spin_lock_irqsave(&info->lock[RX], flags);
647 	if (info->notify_updated[RX]) {
648 		memcpy(&msg, &info->notify[RX], sizeof(struct rpmsg_s_msg));
649 		info->notify_updated[RX] = false;
650 		spin_unlock_irqrestore(&info->lock[RX], flags);
651 		info->send_message(&msg, info);
652 	} else {
653 		spin_unlock_irqrestore(&info->lock[RX], flags);
654 	}
655 
656 	/* Skip the notification message for it has been processed above */
657 	if (work_of_rpmsg->msg.s_msg.header.type == MSG_TYPE_C &&
658 	    (work_of_rpmsg->msg.s_msg.header.cmd == TX_PERIOD_DONE ||
659 	     work_of_rpmsg->msg.s_msg.header.cmd == RX_PERIOD_DONE))
660 		is_notification = true;
661 
662 	if (!is_notification)
663 		info->send_message(&work_of_rpmsg->msg, info);
664 
665 	/* update read index */
666 	spin_lock_irqsave(&info->wq_lock, flags);
667 	info->work_read_index++;
668 	info->work_read_index %= WORK_MAX_NUM;
669 	spin_unlock_irqrestore(&info->wq_lock, flags);
670 }
671 
672 static int imx_rpmsg_pcm_probe(struct platform_device *pdev)
673 {
674 	struct snd_soc_component *component;
675 	struct rpmsg_info *info;
676 	int ret, i;
677 
678 	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
679 	if (!info)
680 		return -ENOMEM;
681 
682 	platform_set_drvdata(pdev, info);
683 
684 	info->rpdev = container_of(pdev->dev.parent, struct rpmsg_device, dev);
685 	info->dev = &pdev->dev;
686 	/* Setup work queue */
687 	info->rpmsg_wq = alloc_ordered_workqueue(info->rpdev->id.name,
688 						 WQ_HIGHPRI |
689 						 WQ_UNBOUND |
690 						 WQ_FREEZABLE);
691 	if (!info->rpmsg_wq) {
692 		dev_err(&pdev->dev, "workqueue create failed\n");
693 		return -ENOMEM;
694 	}
695 
696 	/* Write index initialize 1, make it differ with the read index */
697 	info->work_write_index = 1;
698 	info->send_message = imx_rpmsg_pcm_send_message;
699 
700 	for (i = 0; i < WORK_MAX_NUM; i++) {
701 		INIT_WORK(&info->work_list[i].work, imx_rpmsg_pcm_work);
702 		info->work_list[i].info = info;
703 	}
704 
705 	/* Initialize msg */
706 	for (i = 0; i < MSG_MAX_NUM; i++) {
707 		info->msg[i].s_msg.header.cate  = IMX_RPMSG_AUDIO;
708 		info->msg[i].s_msg.header.major = IMX_RMPSG_MAJOR;
709 		info->msg[i].s_msg.header.minor = IMX_RMPSG_MINOR;
710 		info->msg[i].s_msg.header.type  = MSG_TYPE_A;
711 		info->msg[i].s_msg.param.audioindex = 0;
712 	}
713 
714 	init_completion(&info->cmd_complete);
715 	mutex_init(&info->msg_lock);
716 	spin_lock_init(&info->lock[TX]);
717 	spin_lock_init(&info->lock[RX]);
718 	spin_lock_init(&info->wq_lock);
719 
720 	ret = devm_snd_soc_register_component(&pdev->dev,
721 					      &imx_rpmsg_soc_component,
722 					      NULL, 0);
723 	if (ret)
724 		goto fail;
725 
726 	component = snd_soc_lookup_component(&pdev->dev, NULL);
727 	if (!component) {
728 		ret = -EINVAL;
729 		goto fail;
730 	}
731 
732 	/* platform component name is used by machine driver to link with */
733 	component->name = info->rpdev->id.name;
734 
735 #ifdef CONFIG_DEBUG_FS
736 	component->debugfs_prefix = "rpmsg";
737 #endif
738 
739 	return 0;
740 
741 fail:
742 	if (info->rpmsg_wq)
743 		destroy_workqueue(info->rpmsg_wq);
744 
745 	return ret;
746 }
747 
748 static int imx_rpmsg_pcm_remove(struct platform_device *pdev)
749 {
750 	struct rpmsg_info *info = platform_get_drvdata(pdev);
751 
752 	if (info->rpmsg_wq)
753 		destroy_workqueue(info->rpmsg_wq);
754 
755 	return 0;
756 }
757 
758 #ifdef CONFIG_PM
759 static int imx_rpmsg_pcm_runtime_resume(struct device *dev)
760 {
761 	struct rpmsg_info *info = dev_get_drvdata(dev);
762 
763 	cpu_latency_qos_add_request(&info->pm_qos_req, 0);
764 
765 	return 0;
766 }
767 
768 static int imx_rpmsg_pcm_runtime_suspend(struct device *dev)
769 {
770 	struct rpmsg_info *info = dev_get_drvdata(dev);
771 
772 	cpu_latency_qos_remove_request(&info->pm_qos_req);
773 
774 	return 0;
775 }
776 #endif
777 
778 #ifdef CONFIG_PM_SLEEP
779 static int imx_rpmsg_pcm_suspend(struct device *dev)
780 {
781 	struct rpmsg_info *info = dev_get_drvdata(dev);
782 	struct rpmsg_msg *rpmsg_tx;
783 	struct rpmsg_msg *rpmsg_rx;
784 
785 	rpmsg_tx = &info->msg[TX_SUSPEND];
786 	rpmsg_rx = &info->msg[RX_SUSPEND];
787 
788 	rpmsg_tx->s_msg.header.cmd = TX_SUSPEND;
789 	info->send_message(rpmsg_tx, info);
790 
791 	rpmsg_rx->s_msg.header.cmd = RX_SUSPEND;
792 	info->send_message(rpmsg_rx, info);
793 
794 	return 0;
795 }
796 
797 static int imx_rpmsg_pcm_resume(struct device *dev)
798 {
799 	struct rpmsg_info *info = dev_get_drvdata(dev);
800 	struct rpmsg_msg *rpmsg_tx;
801 	struct rpmsg_msg *rpmsg_rx;
802 
803 	rpmsg_tx = &info->msg[TX_RESUME];
804 	rpmsg_rx = &info->msg[RX_RESUME];
805 
806 	rpmsg_tx->s_msg.header.cmd = TX_RESUME;
807 	info->send_message(rpmsg_tx, info);
808 
809 	rpmsg_rx->s_msg.header.cmd = RX_RESUME;
810 	info->send_message(rpmsg_rx, info);
811 
812 	return 0;
813 }
814 #endif /* CONFIG_PM_SLEEP */
815 
816 static const struct dev_pm_ops imx_rpmsg_pcm_pm_ops = {
817 	SET_RUNTIME_PM_OPS(imx_rpmsg_pcm_runtime_suspend,
818 			   imx_rpmsg_pcm_runtime_resume,
819 			   NULL)
820 	SET_SYSTEM_SLEEP_PM_OPS(imx_rpmsg_pcm_suspend,
821 				imx_rpmsg_pcm_resume)
822 };
823 
824 static struct platform_driver imx_pcm_rpmsg_driver = {
825 	.probe  = imx_rpmsg_pcm_probe,
826 	.remove	= imx_rpmsg_pcm_remove,
827 	.driver = {
828 		.name = IMX_PCM_DRV_NAME,
829 		.pm = &imx_rpmsg_pcm_pm_ops,
830 	},
831 };
832 module_platform_driver(imx_pcm_rpmsg_driver);
833 
834 MODULE_DESCRIPTION("Freescale SoC Audio RPMSG PCM interface");
835 MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
836 MODULE_ALIAS("platform:" IMX_PCM_DRV_NAME);
837 MODULE_LICENSE("GPL v2");
838