sound/soc/intel/baytrail/sst-baytrail-pcm.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Intel Baytrail SST PCM Support
  * Copyright (c) 2014, Intel Corporation.
  */

 #include <linux/module.h>
 #include <linux/dma-mapping.h>
 #include <linux/slab.h>
 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include "sst-baytrail-ipc.h"
 #include "../common/sst-dsp-priv.h"
 #include "../common/sst-dsp.h"

 #define DRV_NAME "byt-dai"
 #define BYT_PCM_COUNT		2

 static const struct snd_pcm_hardware sst_byt_pcm_hardware = {
 	.info			= SNDRV_PCM_INFO_MMAP |
 				  SNDRV_PCM_INFO_MMAP_VALID |
 				  SNDRV_PCM_INFO_INTERLEAVED |
 				  SNDRV_PCM_INFO_PAUSE |
 				  SNDRV_PCM_INFO_RESUME,
 	.formats		= SNDRV_PCM_FMTBIT_S16_LE |
 				  SNDRV_PCM_FMTBIT_S24_LE,
 	.period_bytes_min	= 384,
 	.period_bytes_max	= 48000,
 	.periods_min		= 2,
 	.periods_max		= 250,
 	.buffer_bytes_max	= 96000,
 };

 /* private data for each PCM DSP stream */
 struct sst_byt_pcm_data {
 	struct sst_byt_stream *stream;
 	struct snd_pcm_substream *substream;
 	struct mutex mutex;

 	/* latest DSP DMA hw pointer */
 	u32 hw_ptr;

 	struct work_struct work;
 };

 /* private data for the driver */
 struct sst_byt_priv_data {
 	/* runtime DSP */
 	struct sst_byt *byt;

 	/* DAI data */
 	struct sst_byt_pcm_data pcm[BYT_PCM_COUNT];

 	/* flag indicating is stream context restore needed after suspend */
 	bool restore_stream;
 };

 /* this may get called several times by oss emulation */
 static int sst_byt_pcm_hw_params(struct snd_soc_component *component,
 				 struct snd_pcm_substream *substream,
 				 struct snd_pcm_hw_params *params)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
 	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
 	struct sst_byt *byt = pdata->byt;
 	u32 rate, bits;
 	u8 channels;
 	int ret, playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);

 	dev_dbg(rtd->dev, "PCM: hw_params, pcm_data %p\n", pcm_data);

 	ret = sst_byt_stream_type(byt, pcm_data->stream,
 				  1, 1, !playback);
 	if (ret < 0) {
 		dev_err(rtd->dev, "failed to set stream format %d\n", ret);
 		return ret;
 	}

 	rate = params_rate(params);
 	ret = sst_byt_stream_set_rate(byt, pcm_data->stream, rate);
 	if (ret < 0) {
 		dev_err(rtd->dev, "could not set rate %d\n", rate);
 		return ret;
 	}

 	bits = snd_pcm_format_width(params_format(params));
 	ret = sst_byt_stream_set_bits(byt, pcm_data->stream, bits);
 	if (ret < 0) {
 		dev_err(rtd->dev, "could not set formats %d\n",
 			params_rate(params));
 		return ret;
 	}

 	channels = (u8)(params_channels(params) & 0xF);
 	ret = sst_byt_stream_set_channels(byt, pcm_data->stream, channels);
 	if (ret < 0) {
 		dev_err(rtd->dev, "could not set channels %d\n",
 			params_rate(params));
 		return ret;
 	}

 	ret = sst_byt_stream_buffer(byt, pcm_data->stream,
 				    substream->dma_buffer.addr,
 				    params_buffer_bytes(params));
 	if (ret < 0) {
 		dev_err(rtd->dev, "PCM: failed to set DMA buffer %d\n", ret);
 		return ret;
 	}

 	ret = sst_byt_stream_commit(byt, pcm_data->stream);
 	if (ret < 0) {
 		dev_err(rtd->dev, "PCM: failed stream commit %d\n", ret);
 		return ret;
 	}

 	return 0;
 }

 static int sst_byt_pcm_restore_stream_context(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
 	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
 	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
 	struct sst_byt *byt = pdata->byt;
 	int ret;

 	/* commit stream using existing stream params */
 	ret = sst_byt_stream_commit(byt, pcm_data->stream);
 	if (ret < 0) {
 		dev_err(rtd->dev, "PCM: failed stream commit %d\n", ret);
 		return ret;
 	}

 	sst_byt_stream_start(byt, pcm_data->stream, pcm_data->hw_ptr);

 	dev_dbg(rtd->dev, "stream context restored at offset %d\n",
 		pcm_data->hw_ptr);

 	return 0;
 }

 static void sst_byt_pcm_work(struct work_struct *work)
 {
 	struct sst_byt_pcm_data *pcm_data =
 		container_of(work, struct sst_byt_pcm_data, work);

 	if (snd_pcm_running(pcm_data->substream))
 		sst_byt_pcm_restore_stream_context(pcm_data->substream);
 }

 static int sst_byt_pcm_trigger(struct snd_soc_component *component,
 			       struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
 	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
 	struct sst_byt *byt = pdata->byt;

 	dev_dbg(rtd->dev, "PCM: trigger %d\n", cmd);

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		pcm_data->hw_ptr = 0;
 		sst_byt_stream_start(byt, pcm_data->stream, 0);
 		break;
 	case SNDRV_PCM_TRIGGER_RESUME:
 		if (pdata->restore_stream)
 			schedule_work(&pcm_data->work);
 		else
 			sst_byt_stream_resume(byt, pcm_data->stream);
 		break;
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		sst_byt_stream_resume(byt, pcm_data->stream);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 		sst_byt_stream_stop(byt, pcm_data->stream);
 		break;
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 		pdata->restore_stream = false;
 		fallthrough;
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		sst_byt_stream_pause(byt, pcm_data->stream);
 		break;
 	default:
 		break;
 	}

 	return 0;
 }

 static u32 byt_notify_pointer(struct sst_byt_stream *stream, void *data)
 {
 	struct sst_byt_pcm_data *pcm_data = data;
 	struct snd_pcm_substream *substream = pcm_data->substream;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
 	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
 	struct sst_byt *byt = pdata->byt;
 	u32 pos, hw_pos;

 	hw_pos = sst_byt_get_dsp_position(byt, pcm_data->stream,
 					  snd_pcm_lib_buffer_bytes(substream));
 	pcm_data->hw_ptr = hw_pos;
 	pos = frames_to_bytes(runtime,
 			      (runtime->control->appl_ptr %
 			       runtime->buffer_size));

 	dev_dbg(rtd->dev, "PCM: App/DMA pointer %u/%u bytes\n", pos, hw_pos);

 	snd_pcm_period_elapsed(substream);
 	return pos;
 }

 static snd_pcm_uframes_t sst_byt_pcm_pointer(struct snd_soc_component *component,
 					     struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
 	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];

 	dev_dbg(rtd->dev, "PCM: DMA pointer %u bytes\n", pcm_data->hw_ptr);

 	return bytes_to_frames(runtime, pcm_data->hw_ptr);
 }

 static int sst_byt_pcm_open(struct snd_soc_component *component,
 			    struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
 	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
 	struct sst_byt *byt = pdata->byt;

 	dev_dbg(rtd->dev, "PCM: open\n");

 	mutex_lock(&pcm_data->mutex);

 	pcm_data->substream = substream;

 	snd_soc_set_runtime_hwparams(substream, &sst_byt_pcm_hardware);

 	pcm_data->stream = sst_byt_stream_new(byt, substream->stream + 1,
 					      byt_notify_pointer, pcm_data);
 	if (pcm_data->stream == NULL) {
 		dev_err(rtd->dev, "failed to create stream\n");
 		mutex_unlock(&pcm_data->mutex);
 		return -EINVAL;
 	}

 	mutex_unlock(&pcm_data->mutex);
 	return 0;
 }

 static int sst_byt_pcm_close(struct snd_soc_component *component,
 			     struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
 	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
 	struct sst_byt *byt = pdata->byt;
 	int ret;

 	dev_dbg(rtd->dev, "PCM: close\n");

 	cancel_work_sync(&pcm_data->work);
 	mutex_lock(&pcm_data->mutex);
 	ret = sst_byt_stream_free(byt, pcm_data->stream);
 	if (ret < 0) {
 		dev_dbg(rtd->dev, "Free stream fail\n");
 		goto out;
 	}
 	pcm_data->stream = NULL;

 out:
 	mutex_unlock(&pcm_data->mutex);
 	return ret;
 }

 static int sst_byt_pcm_mmap(struct snd_soc_component *component,
 			    struct snd_pcm_substream *substream,
 			    struct vm_area_struct *vma)
 {
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);

 	dev_dbg(rtd->dev, "PCM: mmap\n");
 	return snd_pcm_lib_default_mmap(substream, vma);
 }

 static int sst_byt_pcm_new(struct snd_soc_component *component,
 			   struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_pcm *pcm = rtd->pcm;
 	size_t size;
 	struct sst_pdata *pdata = dev_get_platdata(component->dev);

 	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream ||
 	    pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
 		size = sst_byt_pcm_hardware.buffer_bytes_max;
 		snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
 					       pdata->dma_dev, size, size);
 	}

 	return 0;
 }

 static struct snd_soc_dai_driver byt_dais[] = {
 	{
 		.name  = "Baytrail PCM",
 		.playback = {
 			.stream_name = "System Playback",
 			.channels_min = 2,
 			.channels_max = 2,
 			.rates = SNDRV_PCM_RATE_48000,
 			.formats = SNDRV_PCM_FMTBIT_S24_3LE |
 				   SNDRV_PCM_FMTBIT_S16_LE,
 		},
 		.capture = {
 			.stream_name = "Analog Capture",
 			.channels_min = 2,
 			.channels_max = 2,
 			.rates = SNDRV_PCM_RATE_48000,
 			.formats = SNDRV_PCM_FMTBIT_S16_LE,
 		},
 	},
 };

 static int sst_byt_pcm_probe(struct snd_soc_component *component)
 {
 	struct sst_pdata *plat_data = dev_get_platdata(component->dev);
 	struct sst_byt_priv_data *priv_data;
 	int i;

 	if (!plat_data)
 		return -ENODEV;

 	priv_data = devm_kzalloc(component->dev, sizeof(*priv_data),
 				 GFP_KERNEL);
 	if (!priv_data)
 		return -ENOMEM;
 	priv_data->byt = plat_data->dsp;
 	snd_soc_component_set_drvdata(component, priv_data);

 	for (i = 0; i < BYT_PCM_COUNT; i++) {
 		mutex_init(&priv_data->pcm[i].mutex);
 		INIT_WORK(&priv_data->pcm[i].work, sst_byt_pcm_work);
 	}

 	return 0;
 }

 static const struct snd_soc_component_driver byt_dai_component = {
 	.name		= DRV_NAME,
 	.probe		= sst_byt_pcm_probe,
 	.open		= sst_byt_pcm_open,
 	.close		= sst_byt_pcm_close,
 	.hw_params	= sst_byt_pcm_hw_params,
 	.trigger	= sst_byt_pcm_trigger,
 	.pointer	= sst_byt_pcm_pointer,
 	.mmap		= sst_byt_pcm_mmap,
 	.pcm_construct	= sst_byt_pcm_new,
 };

 #ifdef CONFIG_PM
 static int sst_byt_pcm_dev_suspend_late(struct device *dev)
 {
 	struct sst_pdata *sst_pdata = dev_get_platdata(dev);
 	struct sst_byt_priv_data *priv_data = dev_get_drvdata(dev);
 	int ret;

 	dev_dbg(dev, "suspending late\n");

 	ret = sst_byt_dsp_suspend_late(dev, sst_pdata);
 	if (ret < 0) {
 		dev_err(dev, "failed to suspend %d\n", ret);
 		return ret;
 	}

 	priv_data->restore_stream = true;

 	return ret;
 }

 static int sst_byt_pcm_dev_resume_early(struct device *dev)
 {
 	struct sst_pdata *sst_pdata = dev_get_platdata(dev);
 	int ret;

 	dev_dbg(dev, "resume early\n");

 	/* load fw and boot DSP */
 	ret = sst_byt_dsp_boot(dev, sst_pdata);
 	if (ret)
 		return ret;

 	/* wait for FW to finish booting */
 	return sst_byt_dsp_wait_for_ready(dev, sst_pdata);
 }

 static const struct dev_pm_ops sst_byt_pm_ops = {
 	.suspend_late = sst_byt_pcm_dev_suspend_late,
 	.resume_early = sst_byt_pcm_dev_resume_early,
 };

 #define SST_BYT_PM_OPS	(&sst_byt_pm_ops)
 #else
 #define SST_BYT_PM_OPS	NULL
 #endif

 static int sst_byt_pcm_dev_probe(struct platform_device *pdev)
 {
 	struct sst_pdata *sst_pdata = dev_get_platdata(&pdev->dev);
 	int ret;

 	ret = sst_byt_dsp_init(&pdev->dev, sst_pdata);
 	if (ret < 0)
 		return -ENODEV;

 	ret = devm_snd_soc_register_component(&pdev->dev, &byt_dai_component,
 					 byt_dais, ARRAY_SIZE(byt_dais));
 	if (ret < 0)
 		goto err_plat;

 	return 0;

 err_plat:
 	sst_byt_dsp_free(&pdev->dev, sst_pdata);
 	return ret;
 }

 static int sst_byt_pcm_dev_remove(struct platform_device *pdev)
 {
 	struct sst_pdata *sst_pdata = dev_get_platdata(&pdev->dev);

 	sst_byt_dsp_free(&pdev->dev, sst_pdata);

 	return 0;
 }

 static struct platform_driver sst_byt_pcm_driver = {
 	.driver = {
 		.name = "baytrail-pcm-audio",
 		.pm = SST_BYT_PM_OPS,
 	},

 	.probe = sst_byt_pcm_dev_probe,
 	.remove = sst_byt_pcm_dev_remove,
 };
 module_platform_driver(sst_byt_pcm_driver);

 MODULE_AUTHOR("Jarkko Nikula");
 MODULE_DESCRIPTION("Baytrail PCM");
 MODULE_LICENSE("GPL v2");
 MODULE_ALIAS("platform:baytrail-pcm-audio");
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Intel Baytrail SST PCM Support
	* Copyright (c) 2014, Intel Corporation.
	*/

	#include <linux/module.h>
	#include <linux/dma-mapping.h>
	#include <linux/slab.h>
	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>
	#include "sst-baytrail-ipc.h"
	#include "../common/sst-dsp-priv.h"
	#include "../common/sst-dsp.h"

	#define DRV_NAME "byt-dai"
	#define BYT_PCM_COUNT 2

	static const struct snd_pcm_hardware sst_byt_pcm_hardware = {
	.info = SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_MMAP_VALID \|
	SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_PAUSE \|
	SNDRV_PCM_INFO_RESUME,
	.formats = SNDRV_PCM_FMTBIT_S16_LE \|
	SNDRV_PCM_FMTBIT_S24_LE,
	.period_bytes_min = 384,
	.period_bytes_max = 48000,
	.periods_min = 2,
	.periods_max = 250,
	.buffer_bytes_max = 96000,
	};

	/* private data for each PCM DSP stream */
	struct sst_byt_pcm_data {
	struct sst_byt_stream *stream;
	struct snd_pcm_substream *substream;
	struct mutex mutex;

	/* latest DSP DMA hw pointer */
	u32 hw_ptr;

	struct work_struct work;
	};

	/* private data for the driver */
	struct sst_byt_priv_data {
	/* runtime DSP */
	struct sst_byt *byt;

	/* DAI data */
	struct sst_byt_pcm_data pcm[BYT_PCM_COUNT];

	/* flag indicating is stream context restore needed after suspend */
	bool restore_stream;
	};

	/* this may get called several times by oss emulation */
	static int sst_byt_pcm_hw_params(struct snd_soc_component *component,
	struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
	{
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
	struct sst_byt *byt = pdata->byt;
	u32 rate, bits;
	u8 channels;
	int ret, playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);

	dev_dbg(rtd->dev, "PCM: hw_params, pcm_data %p\n", pcm_data);

	ret = sst_byt_stream_type(byt, pcm_data->stream,
	1, 1, !playback);
	if (ret < 0) {
	dev_err(rtd->dev, "failed to set stream format %d\n", ret);
	return ret;
	}

	rate = params_rate(params);
	ret = sst_byt_stream_set_rate(byt, pcm_data->stream, rate);
	if (ret < 0) {
	dev_err(rtd->dev, "could not set rate %d\n", rate);
	return ret;
	}

	bits = snd_pcm_format_width(params_format(params));
	ret = sst_byt_stream_set_bits(byt, pcm_data->stream, bits);
	if (ret < 0) {
	dev_err(rtd->dev, "could not set formats %d\n",
	params_rate(params));
	return ret;
	}

	channels = (u8)(params_channels(params) & 0xF);
	ret = sst_byt_stream_set_channels(byt, pcm_data->stream, channels);
	if (ret < 0) {
	dev_err(rtd->dev, "could not set channels %d\n",
	params_rate(params));
	return ret;
	}

	ret = sst_byt_stream_buffer(byt, pcm_data->stream,
	substream->dma_buffer.addr,
	params_buffer_bytes(params));
	if (ret < 0) {
	dev_err(rtd->dev, "PCM: failed to set DMA buffer %d\n", ret);
	return ret;
	}

	ret = sst_byt_stream_commit(byt, pcm_data->stream);
	if (ret < 0) {
	dev_err(rtd->dev, "PCM: failed stream commit %d\n", ret);
	return ret;
	}

	return 0;
	}

	static int sst_byt_pcm_restore_stream_context(struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
	struct sst_byt *byt = pdata->byt;
	int ret;

	/* commit stream using existing stream params */
	ret = sst_byt_stream_commit(byt, pcm_data->stream);
	if (ret < 0) {
	dev_err(rtd->dev, "PCM: failed stream commit %d\n", ret);
	return ret;
	}

	sst_byt_stream_start(byt, pcm_data->stream, pcm_data->hw_ptr);

	dev_dbg(rtd->dev, "stream context restored at offset %d\n",
	pcm_data->hw_ptr);

	return 0;
	}

	static void sst_byt_pcm_work(struct work_struct *work)
	{
	struct sst_byt_pcm_data *pcm_data =
	container_of(work, struct sst_byt_pcm_data, work);

	if (snd_pcm_running(pcm_data->substream))
	sst_byt_pcm_restore_stream_context(pcm_data->substream);
	}

	static int sst_byt_pcm_trigger(struct snd_soc_component *component,
	struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
	struct sst_byt *byt = pdata->byt;

	dev_dbg(rtd->dev, "PCM: trigger %d\n", cmd);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	pcm_data->hw_ptr = 0;
	sst_byt_stream_start(byt, pcm_data->stream, 0);
	break;
	case SNDRV_PCM_TRIGGER_RESUME:
	if (pdata->restore_stream)
	schedule_work(&pcm_data->work);
	else
	sst_byt_stream_resume(byt, pcm_data->stream);
	break;
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	sst_byt_stream_resume(byt, pcm_data->stream);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	sst_byt_stream_stop(byt, pcm_data->stream);
	break;
	case SNDRV_PCM_TRIGGER_SUSPEND:
	pdata->restore_stream = false;
	fallthrough;
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	sst_byt_stream_pause(byt, pcm_data->stream);
	break;
	default:
	break;
	}

	return 0;
	}

	static u32 byt_notify_pointer(struct sst_byt_stream stream, void data)
	{
	struct sst_byt_pcm_data *pcm_data = data;
	struct snd_pcm_substream *substream = pcm_data->substream;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct snd_soc_component *component = snd_soc_rtdcom_lookup(rtd, DRV_NAME);
	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
	struct sst_byt *byt = pdata->byt;
	u32 pos, hw_pos;

	hw_pos = sst_byt_get_dsp_position(byt, pcm_data->stream,
	snd_pcm_lib_buffer_bytes(substream));
	pcm_data->hw_ptr = hw_pos;
	pos = frames_to_bytes(runtime,
	(runtime->control->appl_ptr %
	runtime->buffer_size));

	dev_dbg(rtd->dev, "PCM: App/DMA pointer %u/%u bytes\n", pos, hw_pos);

	snd_pcm_period_elapsed(substream);
	return pos;
	}

	static snd_pcm_uframes_t sst_byt_pcm_pointer(struct snd_soc_component *component,
	struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];

	dev_dbg(rtd->dev, "PCM: DMA pointer %u bytes\n", pcm_data->hw_ptr);

	return bytes_to_frames(runtime, pcm_data->hw_ptr);
	}

	static int sst_byt_pcm_open(struct snd_soc_component *component,
	struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
	struct sst_byt *byt = pdata->byt;

	dev_dbg(rtd->dev, "PCM: open\n");

	mutex_lock(&pcm_data->mutex);

	pcm_data->substream = substream;

	snd_soc_set_runtime_hwparams(substream, &sst_byt_pcm_hardware);

	pcm_data->stream = sst_byt_stream_new(byt, substream->stream + 1,
	byt_notify_pointer, pcm_data);
	if (pcm_data->stream == NULL) {
	dev_err(rtd->dev, "failed to create stream\n");
	mutex_unlock(&pcm_data->mutex);
	return -EINVAL;
	}

	mutex_unlock(&pcm_data->mutex);
	return 0;
	}

	static int sst_byt_pcm_close(struct snd_soc_component *component,
	struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct sst_byt_priv_data *pdata = snd_soc_component_get_drvdata(component);
	struct sst_byt_pcm_data *pcm_data = &pdata->pcm[substream->stream];
	struct sst_byt *byt = pdata->byt;
	int ret;

	dev_dbg(rtd->dev, "PCM: close\n");

	cancel_work_sync(&pcm_data->work);
	mutex_lock(&pcm_data->mutex);
	ret = sst_byt_stream_free(byt, pcm_data->stream);
	if (ret < 0) {
	dev_dbg(rtd->dev, "Free stream fail\n");
	goto out;
	}
	pcm_data->stream = NULL;

	out:
	mutex_unlock(&pcm_data->mutex);
	return ret;
	}

	static int sst_byt_pcm_mmap(struct snd_soc_component *component,
	struct snd_pcm_substream *substream,
	struct vm_area_struct *vma)
	{
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);

	dev_dbg(rtd->dev, "PCM: mmap\n");
	return snd_pcm_lib_default_mmap(substream, vma);
	}

	static int sst_byt_pcm_new(struct snd_soc_component *component,
	struct snd_soc_pcm_runtime *rtd)
	{
	struct snd_pcm *pcm = rtd->pcm;
	size_t size;
	struct sst_pdata *pdata = dev_get_platdata(component->dev);

	if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream \|\|
	pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
	size = sst_byt_pcm_hardware.buffer_bytes_max;
	snd_pcm_set_managed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
	pdata->dma_dev, size, size);
	}

	return 0;
	}

	static struct snd_soc_dai_driver byt_dais[] = {
	{
	.name = "Baytrail PCM",
	.playback = {
	.stream_name = "System Playback",
	.channels_min = 2,
	.channels_max = 2,
	.rates = SNDRV_PCM_RATE_48000,
	.formats = SNDRV_PCM_FMTBIT_S24_3LE \|
	SNDRV_PCM_FMTBIT_S16_LE,
	},
	.capture = {
	.stream_name = "Analog Capture",
	.channels_min = 2,
	.channels_max = 2,
	.rates = SNDRV_PCM_RATE_48000,
	.formats = SNDRV_PCM_FMTBIT_S16_LE,
	},
	},
	};

	static int sst_byt_pcm_probe(struct snd_soc_component *component)
	{
	struct sst_pdata *plat_data = dev_get_platdata(component->dev);
	struct sst_byt_priv_data *priv_data;
	int i;

	if (!plat_data)
	return -ENODEV;

	priv_data = devm_kzalloc(component->dev, sizeof(*priv_data),
	GFP_KERNEL);
	if (!priv_data)
	return -ENOMEM;
	priv_data->byt = plat_data->dsp;
	snd_soc_component_set_drvdata(component, priv_data);

	for (i = 0; i < BYT_PCM_COUNT; i++) {
	mutex_init(&priv_data->pcm[i].mutex);
	INIT_WORK(&priv_data->pcm[i].work, sst_byt_pcm_work);
	}

	return 0;
	}

	static const struct snd_soc_component_driver byt_dai_component = {
	.name = DRV_NAME,
	.probe = sst_byt_pcm_probe,
	.open = sst_byt_pcm_open,
	.close = sst_byt_pcm_close,
	.hw_params = sst_byt_pcm_hw_params,
	.trigger = sst_byt_pcm_trigger,
	.pointer = sst_byt_pcm_pointer,
	.mmap = sst_byt_pcm_mmap,
	.pcm_construct = sst_byt_pcm_new,
	};

	#ifdef CONFIG_PM
	static int sst_byt_pcm_dev_suspend_late(struct device *dev)
	{
	struct sst_pdata *sst_pdata = dev_get_platdata(dev);
	struct sst_byt_priv_data *priv_data = dev_get_drvdata(dev);
	int ret;

	dev_dbg(dev, "suspending late\n");

	ret = sst_byt_dsp_suspend_late(dev, sst_pdata);
	if (ret < 0) {
	dev_err(dev, "failed to suspend %d\n", ret);
	return ret;
	}

	priv_data->restore_stream = true;

	return ret;
	}

	static int sst_byt_pcm_dev_resume_early(struct device *dev)
	{
	struct sst_pdata *sst_pdata = dev_get_platdata(dev);
	int ret;

	dev_dbg(dev, "resume early\n");

	/* load fw and boot DSP */
	ret = sst_byt_dsp_boot(dev, sst_pdata);
	if (ret)
	return ret;

	/* wait for FW to finish booting */
	return sst_byt_dsp_wait_for_ready(dev, sst_pdata);
	}

	static const struct dev_pm_ops sst_byt_pm_ops = {
	.suspend_late = sst_byt_pcm_dev_suspend_late,
	.resume_early = sst_byt_pcm_dev_resume_early,
	};

	#define SST_BYT_PM_OPS (&sst_byt_pm_ops)
	#else
	#define SST_BYT_PM_OPS NULL
	#endif

	static int sst_byt_pcm_dev_probe(struct platform_device *pdev)
	{
	struct sst_pdata *sst_pdata = dev_get_platdata(&pdev->dev);
	int ret;

	ret = sst_byt_dsp_init(&pdev->dev, sst_pdata);
	if (ret < 0)
	return -ENODEV;

	ret = devm_snd_soc_register_component(&pdev->dev, &byt_dai_component,
	byt_dais, ARRAY_SIZE(byt_dais));
	if (ret < 0)
	goto err_plat;

	return 0;

	err_plat:
	sst_byt_dsp_free(&pdev->dev, sst_pdata);
	return ret;
	}

	static int sst_byt_pcm_dev_remove(struct platform_device *pdev)
	{
	struct sst_pdata *sst_pdata = dev_get_platdata(&pdev->dev);

	sst_byt_dsp_free(&pdev->dev, sst_pdata);

	return 0;
	}

	static struct platform_driver sst_byt_pcm_driver = {
	.driver = {
	.name = "baytrail-pcm-audio",
	.pm = SST_BYT_PM_OPS,
	},

	.probe = sst_byt_pcm_dev_probe,
	.remove = sst_byt_pcm_dev_remove,
	};
	module_platform_driver(sst_byt_pcm_driver);

	MODULE_AUTHOR("Jarkko Nikula");
	MODULE_DESCRIPTION("Baytrail PCM");
	MODULE_LICENSE("GPL v2");
	MODULE_ALIAS("platform:baytrail-pcm-audio");