[v5,5/6] ASoC: imx-pcm-rpmsg: Add platform driver for audio base on rpmsg

diff --git a/sound/soc/fsl/Kconfig b/sound/soc/fsl/Kconfig
index 8dbdc0c5ba58..3d3d14f3793e 100644
--- a/sound/soc/fsl/Kconfig
+++ b/sound/soc/fsl/Kconfig
@@ -133,6 +133,11 @@  config SND_SOC_IMX_AUDIO_RPMSG
 	tristate
 	depends on RPMSG
 
+config SND_SOC_IMX_PCM_RPMSG
+	tristate
+	depends on SND_SOC_IMX_AUDIO_RPMSG
+	select SND_SOC_GENERIC_DMAENGINE_PCM
+
 config SND_SOC_IMX_AUDMUX
 	tristate "Digital Audio Mux module support"
 	help
diff --git a/sound/soc/fsl/Makefile b/sound/soc/fsl/Makefile
index f08f3cd07ff5..ce4f4324c3a2 100644
--- a/sound/soc/fsl/Makefile
+++ b/sound/soc/fsl/Makefile
@@ -61,6 +61,7 @@  obj-$(CONFIG_SND_SOC_IMX_AUDMUX) += snd-soc-imx-audmux.o
 obj-$(CONFIG_SND_SOC_IMX_PCM_FIQ) += imx-pcm-fiq.o
 obj-$(CONFIG_SND_SOC_IMX_PCM_DMA) += imx-pcm-dma.o
 obj-$(CONFIG_SND_SOC_IMX_AUDIO_RPMSG) += imx-audio-rpmsg.o
+obj-$(CONFIG_SND_SOC_IMX_PCM_RPMSG) += imx-pcm-rpmsg.o
 
 # i.MX Machine Support
 snd-soc-eukrea-tlv320-objs := eukrea-tlv320.o
diff --git a/sound/soc/fsl/imx-pcm-rpmsg.c b/sound/soc/fsl/imx-pcm-rpmsg.c
new file mode 100644
index 000000000000..875c0d6df339
--- /dev/null
+++ b/sound/soc/fsl/imx-pcm-rpmsg.c
@@ -0,0 +1,918 @@ 
+// SPDX-License-Identifier: GPL-2.0+
+// Copyright 2017-2021 NXP
+
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/delay.h>
+#include <linux/rpmsg.h>
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/soc.h>
+
+#include "imx-pcm.h"
+#include "fsl_rpmsg.h"
+#include "imx-pcm-rpmsg.h"
+
+static struct snd_pcm_hardware imx_rpmsg_pcm_hardware = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER |
+		SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_NO_PERIOD_WAKEUP |
+		SNDRV_PCM_INFO_PAUSE |
+		SNDRV_PCM_INFO_RESUME,
+	.buffer_bytes_max = IMX_DEFAULT_DMABUF_SIZE,
+	.period_bytes_min = 512,
+	.period_bytes_max = 65536,
+	.periods_min = 2,
+	.periods_max = 6000,
+	.fifo_size = 0,
+};
+
+static int imx_rpmsg_pcm_send_message(struct rpmsg_msg *msg,
+				      struct rpmsg_info *info)
+{
+	struct rpmsg_device *rpdev = info->rpdev;
+	int ret = 0;
+
+	mutex_lock(&info->msg_lock);
+	if (!rpdev) {
+		dev_err(info->dev, "rpmsg channel not ready\n");
+		mutex_unlock(&info->msg_lock);
+		return -EINVAL;
+	}
+
+	dev_dbg(&rpdev->dev, "send cmd %d\n", msg->s_msg.header.cmd);
+
+	if (!(msg->s_msg.header.type == MSG_TYPE_C))
+		reinit_completion(&info->cmd_complete);
+
+	ret = rpmsg_send(rpdev->ept, (void *)&msg->s_msg,
+			 sizeof(struct rpmsg_s_msg));
+	if (ret) {
+		dev_err(&rpdev->dev, "rpmsg_send failed: %d\n", ret);
+		mutex_unlock(&info->msg_lock);
+		return ret;
+	}
+
+	/* No receive msg for TYPE_C command */
+	if (msg->s_msg.header.type == MSG_TYPE_C) {
+		mutex_unlock(&info->msg_lock);
+		return 0;
+	}
+
+	/* wait response from rpmsg */
+	ret = wait_for_completion_timeout(&info->cmd_complete,
+					  msecs_to_jiffies(RPMSG_TIMEOUT));
+	if (!ret) {
+		dev_err(&rpdev->dev, "rpmsg_send cmd %d timeout!\n",
+			msg->s_msg.header.cmd);
+		mutex_unlock(&info->msg_lock);
+		return -ETIMEDOUT;
+	}
+
+	memcpy(&msg->r_msg, &info->r_msg, sizeof(struct rpmsg_r_msg));
+	memcpy(&info->msg[msg->r_msg.header.cmd].r_msg,
+	       &msg->r_msg, sizeof(struct rpmsg_r_msg));
+
+	/*
+	 * Reset the buffer pointer to be zero, actully we have
+	 * set the buffer pointer to be zero in imx_rpmsg_terminate_all
+	 * But if there is timer task queued in queue, after it is
+	 * executed the buffer pointer will be changed, so need to
+	 * reset it again with TERMINATE command.
+	 */
+	switch (msg->s_msg.header.cmd) {
+	case TX_TERMINATE:
+		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
+		break;
+	case RX_TERMINATE:
+		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
+		break;
+	default:
+		break;
+	}
+
+	dev_dbg(&rpdev->dev, "cmd:%d, resp %d\n", msg->s_msg.header.cmd,
+		info->r_msg.param.resp);
+
+	mutex_unlock(&info->msg_lock);
+
+	return 0;
+}
+
+static int imx_rpmsg_insert_workqueue(struct snd_pcm_substream *substream,
+				      struct rpmsg_msg *msg,
+				      struct rpmsg_info *info)
+{
+	unsigned long flags;
+	int ret = 0;
+
+	/*
+	 * Queue the work to workqueue.
+	 * If the queue is full, drop the message.
+	 */
+	spin_lock_irqsave(&info->wq_lock, flags);
+	if (info->work_write_index != info->work_read_index) {
+		int index = info->work_write_index;
+
+		memcpy(&info->work_list[index].msg, msg,
+		       sizeof(struct rpmsg_s_msg));
+
+		queue_work(info->rpmsg_wq, &info->work_list[index].work);
+		info->work_write_index++;
+		info->work_write_index %= WORK_MAX_NUM;
+	} else {
+		info->msg_drop_count[substream->stream]++;
+		ret = -EPIPE;
+	}
+	spin_unlock_irqrestore(&info->wq_lock, flags);
+
+	return ret;
+}
+
+static int imx_rpmsg_pcm_hw_params(struct snd_soc_component *component,
+				   struct snd_pcm_substream *substream,
+				   struct snd_pcm_hw_params *params)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct rpmsg_msg *msg;
+	int ret = 0;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_HW_PARAM];
+		msg->s_msg.header.cmd = TX_HW_PARAM;
+	} else {
+		msg = &info->msg[RX_HW_PARAM];
+		msg->s_msg.header.cmd = RX_HW_PARAM;
+	}
+
+	msg->s_msg.param.rate = params_rate(params);
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S16_LE:
+		msg->s_msg.param.format   = RPMSG_S16_LE;
+		break;
+	case SNDRV_PCM_FORMAT_S24_LE:
+		msg->s_msg.param.format   = RPMSG_S24_LE;
+		break;
+	case SNDRV_PCM_FORMAT_DSD_U16_LE:
+		msg->s_msg.param.format   = SNDRV_PCM_FORMAT_DSD_U16_LE;
+		break;
+	case SNDRV_PCM_FORMAT_DSD_U32_LE:
+		msg->s_msg.param.format   = SNDRV_PCM_FORMAT_DSD_U32_LE;
+		break;
+	default:
+		msg->s_msg.param.format   = RPMSG_S32_LE;
+		break;
+	}
+
+	switch (params_channels(params)) {
+	case 1:
+		msg->s_msg.param.channels = RPMSG_CH_LEFT;
+		break;
+	case 2:
+		msg->s_msg.param.channels = RPMSG_CH_STEREO;
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
+	runtime->dma_bytes = params_buffer_bytes(params);
+
+	info->send_message(msg, info);
+
+	return ret;
+}
+
+static int imx_rpmsg_pcm_hw_free(struct snd_soc_component *component,
+				 struct snd_pcm_substream *substream)
+{
+	snd_pcm_set_runtime_buffer(substream, NULL);
+	return 0;
+}
+
+static snd_pcm_uframes_t imx_rpmsg_pcm_pointer(struct snd_soc_component *component,
+					       struct snd_pcm_substream *substream)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+	unsigned int pos = 0;
+	int buffer_tail = 0;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
+	else
+		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
+
+	buffer_tail = msg->r_msg.param.buffer_tail;
+	pos = buffer_tail * snd_pcm_lib_period_bytes(substream);
+
+	return bytes_to_frames(substream->runtime, pos);
+}
+
+static void imx_rpmsg_timer_callback(struct timer_list *t)
+{
+	struct stream_timer  *stream_timer =
+			from_timer(stream_timer, t, timer);
+	struct snd_pcm_substream *substream = stream_timer->substream;
+	struct rpmsg_info *info = stream_timer->info;
+	struct rpmsg_msg *msg;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
+		msg->s_msg.header.cmd = TX_PERIOD_DONE;
+	} else {
+		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
+		msg->s_msg.header.cmd = RX_PERIOD_DONE;
+	}
+
+	imx_rpmsg_insert_workqueue(substream, msg, info);
+}
+
+static int imx_rpmsg_pcm_open(struct snd_soc_component *component,
+			      struct snd_pcm_substream *substream)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+	int ret = 0;
+	int cmd;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_OPEN];
+		msg->s_msg.header.cmd = TX_OPEN;
+
+		/* reinitialize buffer counter*/
+		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
+		info->msg[cmd].s_msg.param.buffer_tail = 0;
+		info->msg[cmd].r_msg.param.buffer_tail = 0;
+		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
+
+	} else {
+		msg = &info->msg[RX_OPEN];
+		msg->s_msg.header.cmd = RX_OPEN;
+
+		/* reinitialize buffer counter*/
+		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
+		info->msg[cmd].s_msg.param.buffer_tail = 0;
+		info->msg[cmd].r_msg.param.buffer_tail = 0;
+		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
+	}
+
+	info->send_message(msg, info);
+
+	imx_rpmsg_pcm_hardware.period_bytes_max =
+			imx_rpmsg_pcm_hardware.buffer_bytes_max / 2;
+
+	snd_soc_set_runtime_hwparams(substream, &imx_rpmsg_pcm_hardware);
+
+	ret = snd_pcm_hw_constraint_integer(substream->runtime,
+					    SNDRV_PCM_HW_PARAM_PERIODS);
+	if (ret < 0)
+		return ret;
+
+	info->msg_drop_count[substream->stream] = 0;
+
+	/* Create timer*/
+	info->stream_timer[substream->stream].info = info;
+	info->stream_timer[substream->stream].substream = substream;
+	timer_setup(&info->stream_timer[substream->stream].timer,
+		    imx_rpmsg_timer_callback, 0);
+	return ret;
+}
+
+static int imx_rpmsg_pcm_close(struct snd_soc_component *component,
+			       struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+	int ret = 0;
+
+	/* Flush work in workqueue to make TX_CLOSE is the last message */
+	flush_workqueue(info->rpmsg_wq);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_CLOSE];
+		msg->s_msg.header.cmd = TX_CLOSE;
+	} else {
+		msg = &info->msg[RX_CLOSE];
+		msg->s_msg.header.cmd = RX_CLOSE;
+	}
+
+	info->send_message(msg, info);
+
+	del_timer(&info->stream_timer[substream->stream].timer);
+
+	rtd->dai_link->ignore_suspend = 0;
+
+	if (info->msg_drop_count[substream->stream])
+		dev_warn(rtd->dev, "Msg is dropped!, number is %d\n",
+			 info->msg_drop_count[substream->stream]);
+
+	return ret;
+}
+
+static int imx_rpmsg_pcm_prepare(struct snd_soc_component *component,
+				 struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
+	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
+
+	/*
+	 * NON-MMAP mode, NONBLOCK, Version 2, enable lpa in dts
+	 * four conditions to determine the lpa is enabled.
+	 */
+	if ((runtime->access == SNDRV_PCM_ACCESS_RW_INTERLEAVED ||
+	     runtime->access == SNDRV_PCM_ACCESS_RW_NONINTERLEAVED) &&
+	     rpmsg->enable_lpa) {
+		/*
+		 * Ignore suspend operation in low power mode
+		 * M core will continue playback music on A core suspend.
+		 */
+		rtd->dai_link->ignore_suspend = 1;
+		rpmsg->force_lpa = 1;
+	} else {
+		rpmsg->force_lpa = 0;
+	}
+
+	return 0;
+}
+
+static int imx_rpmsg_pcm_mmap(struct snd_soc_component *component,
+			      struct snd_pcm_substream *substream,
+			      struct vm_area_struct *vma)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+
+	return dma_mmap_wc(substream->pcm->card->dev, vma,
+			   runtime->dma_area,
+			   runtime->dma_addr,
+			   runtime->dma_bytes);
+}
+
+static void imx_rpmsg_pcm_dma_complete(void *arg)
+{
+	struct snd_pcm_substream *substream = arg;
+
+	snd_pcm_period_elapsed(substream);
+}
+
+static int imx_rpmsg_prepare_and_submit(struct snd_soc_component *component,
+					struct snd_pcm_substream *substream)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_BUFFER];
+		msg->s_msg.header.cmd = TX_BUFFER;
+	} else {
+		msg = &info->msg[RX_BUFFER];
+		msg->s_msg.header.cmd = RX_BUFFER;
+	}
+
+	/* Send buffer address and buffer size */
+	msg->s_msg.param.buffer_addr = substream->runtime->dma_addr;
+	msg->s_msg.param.buffer_size = snd_pcm_lib_buffer_bytes(substream);
+	msg->s_msg.param.period_size = snd_pcm_lib_period_bytes(substream);
+	msg->s_msg.param.buffer_tail = 0;
+
+	info->num_period[substream->stream] = msg->s_msg.param.buffer_size /
+					      msg->s_msg.param.period_size;
+
+	info->callback[substream->stream] = imx_rpmsg_pcm_dma_complete;
+	info->callback_param[substream->stream] = substream;
+
+	return imx_rpmsg_insert_workqueue(substream, msg, info);
+}
+
+static int imx_rpmsg_async_issue_pending(struct snd_soc_component *component,
+					 struct snd_pcm_substream *substream)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_START];
+		msg->s_msg.header.cmd = TX_START;
+	} else {
+		msg = &info->msg[RX_START];
+		msg->s_msg.header.cmd = RX_START;
+	}
+
+	return imx_rpmsg_insert_workqueue(substream, msg, info);
+}
+
+static int imx_rpmsg_restart(struct snd_soc_component *component,
+			     struct snd_pcm_substream *substream)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_RESTART];
+		msg->s_msg.header.cmd = TX_RESTART;
+	} else {
+		msg = &info->msg[RX_RESTART];
+		msg->s_msg.header.cmd = RX_RESTART;
+	}
+
+	return imx_rpmsg_insert_workqueue(substream, msg, info);
+}
+
+static int imx_rpmsg_pause(struct snd_soc_component *component,
+			   struct snd_pcm_substream *substream)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_PAUSE];
+		msg->s_msg.header.cmd = TX_PAUSE;
+	} else {
+		msg = &info->msg[RX_PAUSE];
+		msg->s_msg.header.cmd = RX_PAUSE;
+	}
+
+	return imx_rpmsg_insert_workqueue(substream, msg, info);
+}
+
+static int imx_rpmsg_terminate_all(struct snd_soc_component *component,
+				   struct snd_pcm_substream *substream)
+{
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	struct rpmsg_msg *msg;
+	int cmd;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_TERMINATE];
+		msg->s_msg.header.cmd = TX_TERMINATE;
+		/* Clear buffer count*/
+		cmd = TX_PERIOD_DONE + MSG_TYPE_A_NUM;
+		info->msg[cmd].s_msg.param.buffer_tail = 0;
+		info->msg[cmd].r_msg.param.buffer_tail = 0;
+		info->msg[TX_POINTER].r_msg.param.buffer_offset = 0;
+	} else {
+		msg = &info->msg[RX_TERMINATE];
+		msg->s_msg.header.cmd = RX_TERMINATE;
+		/* Clear buffer count*/
+		cmd = RX_PERIOD_DONE + MSG_TYPE_A_NUM;
+		info->msg[cmd].s_msg.param.buffer_tail = 0;
+		info->msg[cmd].r_msg.param.buffer_tail = 0;
+		info->msg[RX_POINTER].r_msg.param.buffer_offset = 0;
+	}
+
+	del_timer(&info->stream_timer[substream->stream].timer);
+
+	return imx_rpmsg_insert_workqueue(substream, msg, info);
+}
+
+static int imx_rpmsg_pcm_trigger(struct snd_soc_component *component,
+				 struct snd_pcm_substream *substream, int cmd)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
+	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+		ret = imx_rpmsg_prepare_and_submit(component, substream);
+		if (ret)
+			return ret;
+		ret = imx_rpmsg_async_issue_pending(component, substream);
+		break;
+	case SNDRV_PCM_TRIGGER_RESUME:
+		if (rpmsg->force_lpa)
+			break;
+		fallthrough;
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		ret = imx_rpmsg_restart(component, substream);
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		if (!rpmsg->force_lpa) {
+			if (runtime->info & SNDRV_PCM_INFO_PAUSE)
+				ret = imx_rpmsg_pause(component, substream);
+			else
+				ret = imx_rpmsg_terminate_all(component, substream);
+		}
+		break;
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		ret = imx_rpmsg_pause(component, substream);
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+		ret = imx_rpmsg_terminate_all(component, substream);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+/*
+ * imx_rpmsg_pcm_ack
+ *
+ * Send the period index to M core through rpmsg, but not send
+ * all the period index to M core, reduce some unnessesary msg
+ * to reduce the pressure of rpmsg bandwidth.
+ */
+static int imx_rpmsg_pcm_ack(struct snd_soc_component *component,
+			     struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *runtime = substream->runtime;
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
+	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
+	struct rpmsg_info *info = dev_get_drvdata(component->dev);
+	snd_pcm_uframes_t period_size = runtime->period_size;
+	snd_pcm_sframes_t avail;
+	struct timer_list *timer;
+	struct rpmsg_msg *msg;
+	unsigned long flags;
+	int buffer_tail = 0;
+	int written_num = 0;
+
+	if (!rpmsg->force_lpa)
+		return 0;
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		msg = &info->msg[TX_PERIOD_DONE + MSG_TYPE_A_NUM];
+		msg->s_msg.header.cmd = TX_PERIOD_DONE;
+	} else {
+		msg = &info->msg[RX_PERIOD_DONE + MSG_TYPE_A_NUM];
+		msg->s_msg.header.cmd = RX_PERIOD_DONE;
+	}
+
+	msg->s_msg.header.type = MSG_TYPE_C;
+
+	buffer_tail = (frames_to_bytes(runtime, runtime->control->appl_ptr) %
+		       snd_pcm_lib_buffer_bytes(substream));
+	buffer_tail = buffer_tail / snd_pcm_lib_period_bytes(substream);
+
+	/* There is update for period index */
+	if (buffer_tail != msg->s_msg.param.buffer_tail) {
+		written_num = buffer_tail - msg->s_msg.param.buffer_tail;
+		if (written_num < 0)
+			written_num += runtime->periods;
+
+		msg->s_msg.param.buffer_tail = buffer_tail;
+
+		/* The notification message is updated to latest */
+		spin_lock_irqsave(&info->lock[substream->stream], flags);
+		memcpy(&info->notify[substream->stream], msg,
+		       sizeof(struct rpmsg_s_msg));
+		info->notify_updated[substream->stream] = true;
+		spin_unlock_irqrestore(&info->lock[substream->stream], flags);
+
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			avail = snd_pcm_playback_hw_avail(runtime);
+		else
+			avail = snd_pcm_capture_hw_avail(runtime);
+
+		timer = &info->stream_timer[substream->stream].timer;
+		/*
+		 * If the data in the buffer is less than one period before
+		 * this fill, which means the data may not enough on M
+		 * core side, we need to send message immediately to let
+		 * M core know the pointer is updated.
+		 * if there is more than one period data in the buffer before
+		 * this fill, which means the data is enough on M core side,
+		 * we can delay one period (using timer) to send the message
+		 * for reduce the message number in workqueue, because the
+		 * pointer may be updated by ack function later, we can
+		 * send latest pointer to M core side.
+		 */
+		if ((avail - written_num * period_size) <= period_size) {
+			imx_rpmsg_insert_workqueue(substream, msg, info);
+		} else if (rpmsg->force_lpa && !timer_pending(timer)) {
+			int time_msec;
+
+			time_msec = (int)(runtime->period_size * 1000 / runtime->rate);
+			mod_timer(timer, jiffies + msecs_to_jiffies(time_msec));
+		}
+	}
+
+	return 0;
+}
+
+static int imx_rpmsg_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
+						int stream, int size)
+{
+	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
+	struct snd_dma_buffer *buf = &substream->dma_buffer;
+
+	buf->dev.type = SNDRV_DMA_TYPE_DEV;
+	buf->dev.dev = pcm->card->dev;
+	buf->private_data = NULL;
+	buf->area = dma_alloc_wc(pcm->card->dev, size,
+				 &buf->addr, GFP_KERNEL);
+	if (!buf->area)
+		return -ENOMEM;
+
+	buf->bytes = size;
+	return 0;
+}
+
+static void imx_rpmsg_pcm_free_dma_buffers(struct snd_soc_component *component,
+					   struct snd_pcm *pcm)
+{
+	struct snd_pcm_substream *substream;
+	struct snd_dma_buffer *buf;
+	int stream;
+
+	for (stream = SNDRV_PCM_STREAM_PLAYBACK;
+	     stream < SNDRV_PCM_STREAM_LAST; stream++) {
+		substream = pcm->streams[stream].substream;
+		if (!substream)
+			continue;
+
+		buf = &substream->dma_buffer;
+		if (!buf->area)
+			continue;
+
+		dma_free_wc(pcm->card->dev, buf->bytes,
+			    buf->area, buf->addr);
+		buf->area = NULL;
+	}
+}
+
+static int imx_rpmsg_pcm_new(struct snd_soc_component *component,
+			     struct snd_soc_pcm_runtime *rtd)
+{
+	struct snd_card *card = rtd->card->snd_card;
+	struct snd_pcm *pcm = rtd->pcm;
+	struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(rtd, 0);
+	struct fsl_rpmsg *rpmsg = dev_get_drvdata(cpu_dai->dev);
+	int ret;
+
+	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
+	if (ret)
+		return ret;
+
+	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
+		ret = imx_rpmsg_pcm_preallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_PLAYBACK,
+							   rpmsg->buffer_size);
+		if (ret)
+			goto out;
+	}
+
+	if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
+		ret = imx_rpmsg_pcm_preallocate_dma_buffer(pcm, SNDRV_PCM_STREAM_CAPTURE,
+							   rpmsg->buffer_size);
+		if (ret)
+			goto out;
+	}
+
+	imx_rpmsg_pcm_hardware.buffer_bytes_max = rpmsg->buffer_size;
+out:
+	/* free preallocated buffers in case of error */
+	if (ret)
+		imx_rpmsg_pcm_free_dma_buffers(component, pcm);
+
+	return ret;
+}
+
+static const struct snd_soc_component_driver imx_rpmsg_soc_component = {
+	.name		= IMX_PCM_DRV_NAME,
+	.pcm_construct	= imx_rpmsg_pcm_new,
+	.pcm_destruct	= imx_rpmsg_pcm_free_dma_buffers,
+	.open		= imx_rpmsg_pcm_open,
+	.close		= imx_rpmsg_pcm_close,
+	.hw_params	= imx_rpmsg_pcm_hw_params,
+	.hw_free	= imx_rpmsg_pcm_hw_free,
+	.trigger	= imx_rpmsg_pcm_trigger,
+	.pointer	= imx_rpmsg_pcm_pointer,
+	.mmap		= imx_rpmsg_pcm_mmap,
+	.ack		= imx_rpmsg_pcm_ack,
+	.prepare	= imx_rpmsg_pcm_prepare,
+};
+
+static void imx_rpmsg_pcm_work(struct work_struct *work)
+{
+	struct work_of_rpmsg *work_of_rpmsg;
+	bool is_notification = false;
+	struct rpmsg_info *info;
+	struct rpmsg_msg msg;
+	unsigned long flags;
+
+	work_of_rpmsg = container_of(work, struct work_of_rpmsg, work);
+	info = work_of_rpmsg->info;
+
+	/*
+	 * Every work in the work queue, first we check if there
+	 * is update for period is filled, because there may be not
+	 * enough data in M core side, need to let M core know
+	 * data is updated immediately.
+	 */
+	spin_lock_irqsave(&info->lock[TX], flags);
+	if (info->notify_updated[TX]) {
+		memcpy(&msg, &info->notify[TX], sizeof(struct rpmsg_s_msg));
+		info->notify_updated[TX] = false;
+		spin_unlock_irqrestore(&info->lock[TX], flags);
+		info->send_message(&msg, info);
+	} else {
+		spin_unlock_irqrestore(&info->lock[TX], flags);
+	}
+
+	spin_lock_irqsave(&info->lock[RX], flags);
+	if (info->notify_updated[RX]) {
+		memcpy(&msg, &info->notify[RX], sizeof(struct rpmsg_s_msg));
+		info->notify_updated[RX] = false;
+		spin_unlock_irqrestore(&info->lock[RX], flags);
+		info->send_message(&msg, info);
+	} else {
+		spin_unlock_irqrestore(&info->lock[RX], flags);
+	}
+
+	/* Skip the notification message for it has been processed above */
+	if (work_of_rpmsg->msg.s_msg.header.type == MSG_TYPE_C &&
+	    (work_of_rpmsg->msg.s_msg.header.cmd == TX_PERIOD_DONE ||
+	     work_of_rpmsg->msg.s_msg.header.cmd == RX_PERIOD_DONE))
+		is_notification = true;
+
+	if (!is_notification)
+		info->send_message(&work_of_rpmsg->msg, info);
+
+	/* update read index */
+	spin_lock_irqsave(&info->wq_lock, flags);
+	info->work_read_index++;
+	info->work_read_index %= WORK_MAX_NUM;
+	spin_unlock_irqrestore(&info->wq_lock, flags);
+}
+
+static int imx_rpmsg_pcm_probe(struct platform_device *pdev)
+{
+	struct snd_soc_component *component;
+	struct rpmsg_info *info;
+	int ret, i;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, info);
+
+	info->rpdev = container_of(pdev->dev.parent, struct rpmsg_device, dev);
+	info->dev = &pdev->dev;
+	/* Setup work queue */
+	info->rpmsg_wq = alloc_ordered_workqueue("rpmsg_audio",
+						 WQ_HIGHPRI |
+						 WQ_UNBOUND |
+						 WQ_FREEZABLE);
+	if (!info->rpmsg_wq) {
+		dev_err(&pdev->dev, "workqueue create failed\n");
+		return -ENOMEM;
+	}
+
+	/* Write index initialize 1, make it differ with the read index */
+	info->work_write_index = 1;
+	info->send_message = imx_rpmsg_pcm_send_message;
+
+	for (i = 0; i < WORK_MAX_NUM; i++) {
+		INIT_WORK(&info->work_list[i].work, imx_rpmsg_pcm_work);
+		info->work_list[i].info = info;
+	}
+
+	/* Initialize msg */
+	for (i = 0; i < MSG_MAX_NUM; i++) {
+		info->msg[i].s_msg.header.cate  = IMX_RPMSG_AUDIO;
+		info->msg[i].s_msg.header.major = IMX_RMPSG_MAJOR;
+		info->msg[i].s_msg.header.minor = IMX_RMPSG_MINOR;
+		info->msg[i].s_msg.header.type  = MSG_TYPE_A;
+		info->msg[i].s_msg.param.audioindex = 0;
+	}
+
+	init_completion(&info->cmd_complete);
+	mutex_init(&info->msg_lock);
+	spin_lock_init(&info->lock[TX]);
+	spin_lock_init(&info->lock[RX]);
+	spin_lock_init(&info->wq_lock);
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+					      &imx_rpmsg_soc_component,
+					      NULL, 0);
+	if (ret)
+		goto fail;
+
+	component = snd_soc_lookup_component(&pdev->dev, IMX_PCM_DRV_NAME);
+	if (!component) {
+		ret = -EINVAL;
+		goto fail;
+	}
+#ifdef CONFIG_DEBUG_FS
+	component->debugfs_prefix = "rpmsg";
+#endif
+
+	return 0;
+
+fail:
+	if (info->rpmsg_wq)
+		destroy_workqueue(info->rpmsg_wq);
+
+	return ret;
+}
+
+static int imx_rpmsg_pcm_remove(struct platform_device *pdev)
+{
+	struct rpmsg_info *info = platform_get_drvdata(pdev);
+
+	if (info->rpmsg_wq)
+		destroy_workqueue(info->rpmsg_wq);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+static int imx_rpmsg_pcm_runtime_resume(struct device *dev)
+{
+	struct rpmsg_info *info = dev_get_drvdata(dev);
+
+	cpu_latency_qos_add_request(&info->pm_qos_req, 0);
+
+	return 0;
+}
+
+static int imx_rpmsg_pcm_runtime_suspend(struct device *dev)
+{
+	struct rpmsg_info *info = dev_get_drvdata(dev);
+
+	cpu_latency_qos_remove_request(&info->pm_qos_req);
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_PM_SLEEP
+static int imx_rpmsg_pcm_suspend(struct device *dev)
+{
+	struct rpmsg_info *info = dev_get_drvdata(dev);
+	struct rpmsg_msg *rpmsg_tx;
+	struct rpmsg_msg *rpmsg_rx;
+
+	rpmsg_tx = &info->msg[TX_SUSPEND];
+	rpmsg_rx = &info->msg[RX_SUSPEND];
+
+	rpmsg_tx->s_msg.header.cmd = TX_SUSPEND;
+	info->send_message(rpmsg_tx, info);
+
+	rpmsg_rx->s_msg.header.cmd = RX_SUSPEND;
+	info->send_message(rpmsg_rx, info);
+
+	return 0;
+}
+
+static int imx_rpmsg_pcm_resume(struct device *dev)
+{
+	struct rpmsg_info *info = dev_get_drvdata(dev);
+	struct rpmsg_msg *rpmsg_tx;
+	struct rpmsg_msg *rpmsg_rx;
+
+	rpmsg_tx = &info->msg[TX_RESUME];
+	rpmsg_rx = &info->msg[RX_RESUME];
+
+	rpmsg_tx->s_msg.header.cmd = TX_RESUME;
+	info->send_message(rpmsg_tx, info);
+
+	rpmsg_rx->s_msg.header.cmd = RX_RESUME;
+	info->send_message(rpmsg_rx, info);
+
+	return 0;
+}
+#endif /* CONFIG_PM_SLEEP */
+
+static const struct dev_pm_ops imx_rpmsg_pcm_pm_ops = {
+	SET_RUNTIME_PM_OPS(imx_rpmsg_pcm_runtime_suspend,
+			   imx_rpmsg_pcm_runtime_resume,
+			   NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(imx_rpmsg_pcm_suspend,
+				imx_rpmsg_pcm_resume)
+};
+
+static struct platform_driver imx_pcm_rpmsg_driver = {
+	.probe  = imx_rpmsg_pcm_probe,
+	.remove	= imx_rpmsg_pcm_remove,
+	.driver = {
+		.name = IMX_PCM_DRV_NAME,
+		.pm = &imx_rpmsg_pcm_pm_ops,
+	},
+};
+module_platform_driver(imx_pcm_rpmsg_driver);
+
+MODULE_DESCRIPTION("Freescale SoC Audio RPMSG PCM interface");
+MODULE_AUTHOR("Shengjiu Wang <shengjiu.wang@nxp.com>");
+MODULE_ALIAS("platform:" IMX_PCM_DRV_NAME);
+MODULE_LICENSE("GPL v2");
diff --git a/sound/soc/fsl/imx-pcm-rpmsg.h b/sound/soc/fsl/imx-pcm-rpmsg.h
new file mode 100644
index 000000000000..308d153920a3
--- /dev/null
+++ b/sound/soc/fsl/imx-pcm-rpmsg.h
@@ -0,0 +1,512 @@ 
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright 2017-2021  NXP
+ *
+ ******************************************************************************
+ * Communication stack of audio with rpmsg
+ ******************************************************************************
+ * Packet structure:
+ *   A SRTM message consists of a 10 bytes header followed by 0~N bytes of data
+ *
+ *   +---------------+-------------------------------+
+ *   |               |            Content            |
+ *   +---------------+-------------------------------+
+ *   |  Byte Offset  | 7   6   5   4   3   2   1   0 |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       0       |           Category            |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |     1 ~ 2     |           Version             |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       3       |             Type              |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       4       |           Command             |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       5       |           Reserved0           |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       6       |           Reserved1           |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       7       |           Reserved2           |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       8       |           Reserved3           |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       9       |           Reserved4           |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |       10      |            DATA 0             |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   :   :   :   :   :   :   :   :   :   :   :   :   :
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *   |   N + 10 - 1  |            DATA N-1           |
+ *   +---------------+---+---+---+---+---+---+---+---+
+ *
+ *   +----------+------------+------------------------------------------------+
+ *   |  Field   |    Byte    |                                                |
+ *   +----------+------------+------------------------------------------------+
+ *   | Category |     0      | The destination category.                      |
+ *   +----------+------------+------------------------------------------------+
+ *   | Version  |   1 ~ 2    | The category version of the sender of the      |
+ *   |          |            | packet.                                        |
+ *   |          |            | The first byte represent the major version of  |
+ *   |          |            | the packet.The second byte represent the minor |
+ *   |          |            | version of the packet.                         |
+ *   +----------+------------+------------------------------------------------+
+ *   |  Type    |     3      | The message type of current message packet.    |
+ *   +----------+------------+------------------------------------------------+
+ *   | Command  |     4      | The command byte sent to remote processor/SoC. |
+ *   +----------+------------+------------------------------------------------+
+ *   | Reserved |   5 ~ 9    | Reserved field for future extension.           |
+ *   +----------+------------+------------------------------------------------+
+ *   | Data     |     N      | The data payload of the message packet.        |
+ *   +----------+------------+------------------------------------------------+
+ *
+ * Audio control:
+ *   SRTM Audio Control Category Request Command Table:
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   | Category | Version | Type | Command | Data                          | Function              |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x00   | Data[0]: Audio Device Index   | Open a TX Instance.   |
+ *   |          |         |      |         | Data[1]:     format           |                       |
+ *   |          |         |      |         | Data[2]:     channels         |                       |
+ *   |          |         |      |         | Data[3-6]:   samplerate       |                       |
+ *   |          |         |      |         | Data[7-10]:  buffer_addr      |                       |
+ *   |          |         |      |         | Data[11-14]: buffer_size      |                       |
+ *   |          |         |      |         | Data[15-18]: period_size      |                       |
+ *   |          |         |      |         | Data[19-22]: buffer_tail      |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x01   | Data[0]: Audio Device Index   | Start a TX Instance.  |
+ *   |          |         |      |         | Same as above command         |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x02   | Data[0]: Audio Device Index   | Pause a TX Instance.  |
+ *   |          |         |      |         | Same as above command         |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x03   | Data[0]: Audio Device Index   | Resume a TX Instance. |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x04   | Data[0]: Audio Device Index   | Stop a TX Instance.   |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x05   | Data[0]: Audio Device Index   | Close a TX Instance.  |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x06   | Data[0]: Audio Device Index   | Set Parameters for    |
+ *   |          |         |      |         | Data[1]:     format           | a TX Instance.        |
+ *   |          |         |      |         | Data[2]:     channels         |                       |
+ *   |          |         |      |         | Data[3-6]:   samplerate       |                       |
+ *   |          |         |      |         | Data[7-22]:  reserved         |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x07   | Data[0]: Audio Device Index   | Set TX Buffer.        |
+ *   |          |         |      |         | Data[1-6]:   reserved         |                       |
+ *   |          |         |      |         | Data[7-10]:  buffer_addr      |                       |
+ *   |          |         |      |         | Data[11-14]: buffer_size      |                       |
+ *   |          |         |      |         | Data[15-18]: period_size      |                       |
+ *   |          |         |      |         | Data[19-22]: buffer_tail      |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x08   | Data[0]: Audio Device Index   | Suspend a TX Instance |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x09   | Data[0]: Audio Device Index   | Resume a TX Instance. |
+ *   |          |         |      |         | Data[1]:     format           |                       |
+ *   |          |         |      |         | Data[2]:     channels         |                       |
+ *   |          |         |      |         | Data[3-6]:   samplerate       |                       |
+ *   |          |         |      |         | Data[7-10]:  buffer_addr      |                       |
+ *   |          |         |      |         | Data[11-14]: buffer_size      |                       |
+ *   |          |         |      |         | Data[15-18]: period_size      |                       |
+ *   |          |         |      |         | Data[19-22]: buffer_tail      |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x0A   | Data[0]: Audio Device Index   | Open a RX Instance.   |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x0B   | Data[0]: Audio Device Index   | Start a RX Instance.  |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x0C   | Data[0]: Audio Device Index   | Pause a RX Instance.  |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x0D   | Data[0]: Audio Device Index   | Resume a RX Instance. |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x0E   | Data[0]: Audio Device Index   | Stop a RX Instance.   |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x0F   | Data[0]: Audio Device Index   | Close a RX Instance.  |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x10   | Data[0]: Audio Device Index   | Set Parameters for    |
+ *   |          |         |      |         | Data[1]:     format           | a RX Instance.        |
+ *   |          |         |      |         | Data[2]:     channels         |                       |
+ *   |          |         |      |         | Data[3-6]:   samplerate       |                       |
+ *   |          |         |      |         | Data[7-22]:  reserved         |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x11   | Data[0]: Audio Device Index   | Set RX Buffer.        |
+ *   |          |         |      |         | Data[1-6]:   reserved         |                       |
+ *   |          |         |      |         | Data[7-10]:  buffer_addr      |                       |
+ *   |          |         |      |         | Data[11-14]: buffer_size      |                       |
+ *   |          |         |      |         | Data[15-18]: period_size      |                       |
+ *   |          |         |      |         | Data[19-22]: buffer_tail      |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x12   | Data[0]: Audio Device Index   | Suspend a RX Instance.|
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x13   | Data[0]: Audio Device Index   | Resume a RX Instance. |
+ *   |          |         |      |         | Data[1]:     format           |                       |
+ *   |          |         |      |         | Data[2]:     channels         |                       |
+ *   |          |         |      |         | Data[3-6]:   samplerate       |                       |
+ *   |          |         |      |         | Data[7-10]:  buffer_addr      |                       |
+ *   |          |         |      |         | Data[11-14]: buffer_size      |                       |
+ *   |          |         |      |         | Data[15-18]: period_size      |                       |
+ *   |          |         |      |         | Data[19-22]: buffer_tail      |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x14   | Data[0]: Audio Device Index   | Set register value    |
+ *   |          |         |      |         | Data[1-6]:   reserved         | to codec              |
+ *   |          |         |      |         | Data[7-10]:  register         |                       |
+ *   |          |         |      |         | Data[11-14]: value            |                       |
+ *   |          |         |      |         | Data[15-22]: reserved         |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x00 |  0x15   | Data[0]: Audio Device Index   | Get register value    |
+ *   |          |         |      |         | Data[1-6]:   reserved         | from codec            |
+ *   |          |         |      |         | Data[7-10]:  register         |                       |
+ *   |          |         |      |         | Data[11-22]: reserved         |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   Note 1: See <List of Sample Format> for available value of
+ *           Sample Format;
+ *   Note 2: See <List of Audio Channels> for available value of Channels;
+ *   Note 3: Sample Rate of Set Parameters for an Audio TX Instance
+ *           Command and Set Parameters for an Audio RX Instance Command is
+ *           in little-endian format.
+ *
+ *   SRTM Audio Control Category Response Command Table:
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   | Category | Version | Type | Command | Data                          | Function              |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x00   | Data[0]: Audio Device Index   | Reply for Open        |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x01   | Data[0]: Audio Device Index   | Reply for Start       |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x02   | Data[0]: Audio Device Index   | Reply for Pause       |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x03   | Data[0]: Audio Device Index   | Reply for Resume      |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x04   | Data[0]: Audio Device Index   | Reply for Stop        |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x05   | Data[0]: Audio Device Index   | Reply for Close       |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x06   | Data[0]: Audio Device Index   | Reply for Set Param   |
+ *   |          |         |      |         | Data[1]: Return code          | for a TX Instance.    |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x07   | Data[0]: Audio Device Index   | Reply for Set         |
+ *   |          |         |      |         | Data[1]: Return code          | TX Buffer             |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x08   | Data[0]: Audio Device Index   | Reply for Suspend     |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x09   | Data[0]: Audio Device Index   | Reply for Resume      |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x0A   | Data[0]: Audio Device Index   | Reply for Open        |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x0B   | Data[0]: Audio Device Index   | Reply for Start       |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x0C   | Data[0]: Audio Device Index   | Reply for Pause       |
+ *   |          |         |      |         | Data[1]: Return code          | a TX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x0D   | Data[0]: Audio Device Index   | Reply for Resume      |
+ *   |          |         |      |         | Data[1]: Return code          | a RX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x0E   | Data[0]: Audio Device Index   | Reply for Stop        |
+ *   |          |         |      |         | Data[1]: Return code          | a RX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x0F   | Data[0]: Audio Device Index   | Reply for Close       |
+ *   |          |         |      |         | Data[1]: Return code          | a RX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x10   | Data[0]: Audio Device Index   | Reply for Set Param   |
+ *   |          |         |      |         | Data[1]: Return code          | for a RX Instance.    |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x11   | Data[0]: Audio Device Index   | Reply for Set         |
+ *   |          |         |      |         | Data[1]: Return code          | RX Buffer             |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x12   | Data[0]: Audio Device Index   | Reply for Suspend     |
+ *   |          |         |      |         | Data[1]: Return code          | a RX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x13   | Data[0]: Audio Device Index   | Reply for Resume      |
+ *   |          |         |      |         | Data[1]: Return code          | a RX Instance         |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x14   | Data[0]: Audio Device Index   | Reply for Set codec   |
+ *   |          |         |      |         | Data[1]: Return code          | register value        |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x01 |  0x15   | Data[0]: Audio Device Index   | Reply for Get codec   |
+ *   |          |         |      |         | Data[1]: Return code          | register value        |
+ *   |          |         |      |         | Data[2-6]:   reserved         |                       |
+ *   |          |         |      |         | Data[7-10]:  register         |                       |
+ *   |          |         |      |         | Data[11-14]: value            |                       |
+ *   |          |         |      |         | Data[15-22]: reserved         |                       |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *
+ *   SRTM Audio Control Category Notification Command Table:
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   | Category | Version | Type | Command | Data                          | Function              |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x02 |  0x00   | Data[0]: Audio Device Index   | Notify one TX period  |
+ *   |          |         |      |         |                               | is finished           |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *   |  0x03    | 0x0100  | 0x02 |  0x01   | Data[0]: Audio Device Index   | Notify one RX period  |
+ *   |          |         |      |         |                               | is finished           |
+ *   +----------+---------+------+---------+-------------------------------+-----------------------+
+ *
+ *   List of Sample Format:
+ *   +------------------+-----------------------+
+ *   | Sample Format    |   Description         |
+ *   +------------------+-----------------------+
+ *   |       0x0        | S16_LE                |
+ *   +------------------+-----------------------+
+ *   |       0x1        | S24_LE                |
+ *   +------------------+-----------------------+
+ *
+ *   List of Audio Channels
+ *   +------------------+-----------------------+
+ *   |  Audio Channel   |   Description         |
+ *   +------------------+-----------------------+
+ *   |       0x0        | Left Channel          |
+ *   +------------------+-----------------------+
+ *   |       0x1        | Right Channel         |
+ *   +------------------+---------------- ------+
+ *   |       0x2        | Left & Right Channel  |
+ *   +------------------+-----------------------+
+ *
+ */
+
+#ifndef _IMX_PCM_RPMSG_H
+#define _IMX_PCM_RPMSG_H
+
+#include <linux/pm_qos.h>
+#include <linux/interrupt.h>
+#include <sound/dmaengine_pcm.h>
+
+#define RPMSG_TIMEOUT 1000
+
+/* RPMSG Command (TYPE A)*/
+#define TX_OPEN		0x0
+#define	TX_START	0x1
+#define	TX_PAUSE	0x2
+#define	TX_RESTART	0x3
+#define	TX_TERMINATE	0x4
+#define	TX_CLOSE	0x5
+#define TX_HW_PARAM	0x6
+#define	TX_BUFFER	0x7
+#define	TX_SUSPEND	0x8
+#define	TX_RESUME	0x9
+
+#define	RX_OPEN		0xA
+#define	RX_START	0xB
+#define	RX_PAUSE	0xC
+#define	RX_RESTART	0xD
+#define	RX_TERMINATE	0xE
+#define	RX_CLOSE	0xF
+#define	RX_HW_PARAM	0x10
+#define	RX_BUFFER	0x11
+#define	RX_SUSPEND	0x12
+#define	RX_RESUME	0x13
+#define SET_CODEC_VALUE 0x14
+#define GET_CODEC_VALUE 0x15
+#define	TX_POINTER	0x16
+#define	RX_POINTER	0x17
+/* Total msg numver for type A */
+#define MSG_TYPE_A_NUM  0x18
+
+/* RPMSG Command (TYPE C)*/
+#define	TX_PERIOD_DONE	0x0
+#define	RX_PERIOD_DONE	0x1
+/* Total msg numver for type C */
+#define MSG_TYPE_C_NUM  0x2
+
+#define MSG_MAX_NUM     (MSG_TYPE_A_NUM + MSG_TYPE_C_NUM)
+
+#define MSG_TYPE_A	0x0
+#define MSG_TYPE_B	0x1
+#define MSG_TYPE_C	0x2
+
+#define RESP_NONE		0x0
+#define RESP_NOT_ALLOWED	0x1
+#define	RESP_SUCCESS		0x2
+#define	RESP_FAILED		0x3
+
+#define	RPMSG_S16_LE		0x0
+#define	RPMSG_S24_LE		0x1
+#define	RPMSG_S32_LE		0x2
+#define	RPMSG_DSD_U16_LE	0x3
+#define	RPMSG_DSD_U24_LE	0x4
+#define	RPMSG_DSD_U32_LE	0x5
+
+#define	RPMSG_CH_LEFT		0x0
+#define	RPMSG_CH_RIGHT		0x1
+#define	RPMSG_CH_STEREO		0x2
+
+#define WORK_MAX_NUM    0x30
+
+/* Category define */
+#define IMX_RMPSG_LIFECYCLE     1
+#define IMX_RPMSG_PMIC          2
+#define IMX_RPMSG_AUDIO         3
+#define IMX_RPMSG_KEY           4
+#define IMX_RPMSG_GPIO          5
+#define IMX_RPMSG_RTC           6
+#define IMX_RPMSG_SENSOR        7
+
+/* rpmsg version */
+#define IMX_RMPSG_MAJOR         1
+#define IMX_RMPSG_MINOR         0
+
+#define TX SNDRV_PCM_STREAM_PLAYBACK
+#define RX SNDRV_PCM_STREAM_CAPTURE
+
+/**
+ * struct rpmsg_head: rpmsg header structure
+ *
+ * @cate: category
+ * @major: major version
+ * @minor: minor version
+ * @type: message type (A/B/C)
+ * @cmd: message command
+ * @reserved: reserved space
+ */
+struct rpmsg_head {
+	u8 cate;
+	u8 major;
+	u8 minor;
+	u8 type;
+	u8 cmd;
+	u8 reserved[5];
+} __packed;
+
+/**
+ * struct param_s: sent rpmsg parameter
+ *
+ * @audioindex: audio instance index
+ * @format: audio format
+ * @channels: audio channel number
+ * @rate: sample rate
+ * @buffer_addr: dma buffer physical address or register for SET_CODEC_VALUE
+ * @buffer_size: dma buffer size or register value for SET_CODEC_VALUE
+ * @period_size: period size
+ * @buffer_tail: current period index
+ */
+struct param_s {
+	unsigned char audioindex;
+	unsigned char format;
+	unsigned char channels;
+	unsigned int  rate;
+	unsigned int  buffer_addr;
+	unsigned int  buffer_size;
+	unsigned int  period_size;
+	unsigned int  buffer_tail;
+} __packed;
+
+/**
+ * struct param_s: send rpmsg parameter
+ *
+ * @audioindex: audio instance index
+ * @resp: response value
+ * @reserved1: reserved space
+ * @buffer_offset: the consumed offset of buffer
+ * @reg_addr: register addr of codec
+ * @reg_data: register value of codec
+ * @reserved2: reserved space
+ * @buffer_tail: current period index
+ */
+struct param_r {
+	unsigned char audioindex;
+	unsigned char resp;
+	unsigned char reserved1[1];
+	unsigned int  buffer_offset;
+	unsigned int  reg_addr;
+	unsigned int  reg_data;
+	unsigned char reserved2[4];
+	unsigned int  buffer_tail;
+} __packed;
+
+/* Struct of sent message */
+struct rpmsg_s_msg {
+	struct rpmsg_head header;
+	struct param_s    param;
+};
+
+/* Struct of received message */
+struct rpmsg_r_msg {
+	struct rpmsg_head header;
+	struct param_r    param;
+};
+
+/* Struct of rpmsg */
+struct rpmsg_msg {
+	struct rpmsg_s_msg  s_msg;
+	struct rpmsg_r_msg  r_msg;
+};
+
+/* Struct of rpmsg for workqueue */
+struct work_of_rpmsg {
+	struct rpmsg_info   *info;
+	/* Sent msg for each work */
+	struct rpmsg_msg    msg;
+	struct work_struct  work;
+};
+
+/* Struct of timer */
+struct stream_timer {
+	struct timer_list   timer;
+	struct rpmsg_info   *info;
+	struct snd_pcm_substream *substream;
+};
+
+typedef void (*dma_callback)(void *arg);
+
+/**
+ * struct rpmsg_info: rpmsg audio information
+ *
+ * @rpdev: pointer of rpmsg_device
+ * @dev: pointer for imx_pcm_rpmsg device
+ * @cmd_complete: command is finished
+ * @pm_qos_req: request of pm qos
+ * @r_msg: received rpmsg
+ * @msg: array of rpmsg
+ * @notify: notification msg (type C) for TX & RX
+ * @notify_updated: notification flag for TX & RX
+ * @rpmsg_wq: rpmsg workqueue
+ * @work_list: array of work list for workqueue
+ * @work_write_index: write index of work list
+ * @work_read_index: read index of work list
+ * @msg_drop_count: counter of dropped msg for TX & RX
+ * @num_period: period number for TX & RX
+ * @callback_param: parameter for period elapse callback for TX & RX
+ * @callback: period elapse callback for TX & RX
+ * @send_message: function pointer for send message
+ * @lock: spin lock for TX & RX
+ * @wq_lock: lock for work queue
+ * @msg_lock: lock for send message
+ * @stream_timer: timer for tigger workqueue
+ */
+struct rpmsg_info {
+	struct rpmsg_device      *rpdev;
+	struct device            *dev;
+	struct completion        cmd_complete;
+	struct pm_qos_request    pm_qos_req;
+
+	/* Received msg (global) */
+	struct rpmsg_r_msg       r_msg;
+	struct rpmsg_msg         msg[MSG_MAX_NUM];
+	/* period done */
+	struct rpmsg_msg         notify[2];
+	bool                     notify_updated[2];
+
+	struct workqueue_struct  *rpmsg_wq;
+	struct work_of_rpmsg	 work_list[WORK_MAX_NUM];
+	int                      work_write_index;
+	int                      work_read_index;
+	int                      msg_drop_count[2];
+	int                      num_period[2];
+	void                     *callback_param[2];
+	dma_callback             callback[2];
+	int (*send_message)(struct rpmsg_msg *msg, struct rpmsg_info *info);
+	spinlock_t               lock[2]; /* spin lock for resource protection */
+	spinlock_t               wq_lock; /* spin lock for resource protection */
+	struct mutex             msg_lock; /* mutex for resource protection */
+	struct stream_timer      stream_timer[2];
+};
+
+#define IMX_PCM_DRV_NAME "imx_pcm_rpmsg"
+
+#endif /* IMX_PCM_RPMSG_H */