sound/soc/fsl/fsl_asrc_dma.c - third_party/kernel - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 //
 // Freescale ASRC ALSA SoC Platform (DMA) driver
 //
 // Copyright (C) 2014 Freescale Semiconductor, Inc.
 //
 // Author: Nicolin Chen <nicoleotsuka@gmail.com>

 #include <linux/dma-mapping.h>
 #include <linux/module.h>
 #include <linux/platform_data/dma-imx.h>
 #include <sound/dmaengine_pcm.h>
 #include <sound/pcm_params.h>

 #include "fsl_asrc_common.h"

 #define FSL_ASRC_DMABUF_SIZE	(256 * 1024)

 static struct snd_pcm_hardware snd_imx_hardware = {
 	.info = SNDRV_PCM_INFO_INTERLEAVED |
 		SNDRV_PCM_INFO_BLOCK_TRANSFER |
 		SNDRV_PCM_INFO_MMAP |
 		SNDRV_PCM_INFO_MMAP_VALID,
 	.buffer_bytes_max = FSL_ASRC_DMABUF_SIZE,
 	.period_bytes_min = 128,
 	.period_bytes_max = 65535, /* Limited by SDMA engine */
 	.periods_min = 2,
 	.periods_max = 255,
 	.fifo_size = 0,
 };

 static bool filter(struct dma_chan *chan, void *param)
 {
 	if (!imx_dma_is_general_purpose(chan))
 		return false;

 	chan->private = param;

 	return true;
 }

 static void fsl_asrc_dma_complete(void *arg)
 {
 	struct snd_pcm_substream *substream = arg;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;

 	pair->pos += snd_pcm_lib_period_bytes(substream);
 	if (pair->pos >= snd_pcm_lib_buffer_bytes(substream))
 		pair->pos = 0;

 	snd_pcm_period_elapsed(substream);
 }

 static int fsl_asrc_dma_prepare_and_submit(struct snd_pcm_substream *substream,
 					   struct snd_soc_component *component)
 {
 	u8 dir = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? OUT : IN;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	struct device *dev = component->dev;
 	unsigned long flags = DMA_CTRL_ACK;

 	/* Prepare and submit Front-End DMA channel */
 	if (!substream->runtime->no_period_wakeup)
 		flags |= DMA_PREP_INTERRUPT;

 	pair->pos = 0;
 	pair->desc[!dir] = dmaengine_prep_dma_cyclic(
 			pair->dma_chan[!dir], runtime->dma_addr,
 			snd_pcm_lib_buffer_bytes(substream),
 			snd_pcm_lib_period_bytes(substream),
 			dir == OUT ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM, flags);
 	if (!pair->desc[!dir]) {
 		dev_err(dev, "failed to prepare slave DMA for Front-End\n");
 		return -ENOMEM;
 	}

 	pair->desc[!dir]->callback = fsl_asrc_dma_complete;
 	pair->desc[!dir]->callback_param = substream;

 	dmaengine_submit(pair->desc[!dir]);

 	/* Prepare and submit Back-End DMA channel */
 	pair->desc[dir] = dmaengine_prep_dma_cyclic(
 			pair->dma_chan[dir], 0xffff, 64, 64, DMA_DEV_TO_DEV, 0);
 	if (!pair->desc[dir]) {
 		dev_err(dev, "failed to prepare slave DMA for Back-End\n");
 		return -ENOMEM;
 	}

 	dmaengine_submit(pair->desc[dir]);

 	return 0;
 }

 static int fsl_asrc_dma_trigger(struct snd_soc_component *component,
 				struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	int ret;

 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 	case SNDRV_PCM_TRIGGER_RESUME:
 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
 		ret = fsl_asrc_dma_prepare_and_submit(substream, component);
 		if (ret)
 			return ret;
 		dma_async_issue_pending(pair->dma_chan[IN]);
 		dma_async_issue_pending(pair->dma_chan[OUT]);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		dmaengine_terminate_all(pair->dma_chan[OUT]);
 		dmaengine_terminate_all(pair->dma_chan[IN]);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return 0;
 }

 static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
 				  struct snd_pcm_substream *substream,
 				  struct snd_pcm_hw_params *params)
 {
 	enum dma_slave_buswidth buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	struct snd_dmaengine_dai_dma_data *dma_params_fe = NULL;
 	struct snd_dmaengine_dai_dma_data *dma_params_be = NULL;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	struct dma_chan *tmp_chan = NULL, *be_chan = NULL;
 	struct snd_soc_component *component_be = NULL;
 	struct fsl_asrc *asrc = pair->asrc;
 	struct dma_slave_config config_fe, config_be;
 	enum asrc_pair_index index = pair->index;
 	struct device *dev = component->dev;
 	struct device_node *of_dma_node;
 	int stream = substream->stream;
 	struct imx_dma_data *tmp_data;
 	struct snd_soc_dpcm *dpcm;
 	struct device *dev_be;
 	u8 dir = tx ? OUT : IN;
 	dma_cap_mask_t mask;
 	int ret, width;

 	/* Fetch the Back-End dma_data from DPCM */
 	for_each_dpcm_be(rtd, stream, dpcm) {
 		struct snd_soc_pcm_runtime *be = dpcm->be;
 		struct snd_pcm_substream *substream_be;
 		struct snd_soc_dai *dai = asoc_rtd_to_cpu(be, 0);

 		if (dpcm->fe != rtd)
 			continue;

 		substream_be = snd_soc_dpcm_get_substream(be, stream);
 		dma_params_be = snd_soc_dai_get_dma_data(dai, substream_be);
 		dev_be = dai->dev;
 		break;
 	}

 	if (!dma_params_be) {
 		dev_err(dev, "failed to get the substream of Back-End\n");
 		return -EINVAL;
 	}

 	/* Override dma_data of the Front-End and config its dmaengine */
 	dma_params_fe = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
 	dma_params_fe->addr = asrc->paddr + asrc->get_fifo_addr(!dir, index);
 	dma_params_fe->maxburst = dma_params_be->maxburst;

 	pair->dma_chan[!dir] = asrc->get_dma_channel(pair, !dir);
 	if (!pair->dma_chan[!dir]) {
 		dev_err(dev, "failed to request DMA channel\n");
 		return -EINVAL;
 	}

 	memset(&config_fe, 0, sizeof(config_fe));
 	ret = snd_dmaengine_pcm_prepare_slave_config(substream, params, &config_fe);
 	if (ret) {
 		dev_err(dev, "failed to prepare DMA config for Front-End\n");
 		return ret;
 	}

 	ret = dmaengine_slave_config(pair->dma_chan[!dir], &config_fe);
 	if (ret) {
 		dev_err(dev, "failed to config DMA channel for Front-End\n");
 		return ret;
 	}

 	/* Request and config DMA channel for Back-End */
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 	dma_cap_set(DMA_CYCLIC, mask);

 	/*
 	 * The Back-End device might have already requested a DMA channel,
 	 * so try to reuse it first, and then request a new one upon NULL.
 	 */
 	component_be = snd_soc_lookup_component_nolocked(dev_be, SND_DMAENGINE_PCM_DRV_NAME);
 	if (component_be) {
 		be_chan = soc_component_to_pcm(component_be)->chan[substream->stream];
 		tmp_chan = be_chan;
 	}
 	if (!tmp_chan)
 		tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");

 	/*
 	 * An EDMA DEV_TO_DEV channel is fixed and bound with DMA event of each
 	 * peripheral, unlike SDMA channel that is allocated dynamically. So no
 	 * need to configure dma_request and dma_request2, but get dma_chan of
 	 * Back-End device directly via dma_request_slave_channel.
 	 */
 	if (!asrc->use_edma) {
 		/* Get DMA request of Back-End */
 		tmp_data = tmp_chan->private;
 		pair->dma_data.dma_request = tmp_data->dma_request;
 		if (!be_chan)
 			dma_release_channel(tmp_chan);

 		/* Get DMA request of Front-End */
 		tmp_chan = asrc->get_dma_channel(pair, dir);
 		tmp_data = tmp_chan->private;
 		pair->dma_data.dma_request2 = tmp_data->dma_request;
 		pair->dma_data.peripheral_type = tmp_data->peripheral_type;
 		pair->dma_data.priority = tmp_data->priority;
 		dma_release_channel(tmp_chan);

 		of_dma_node = pair->dma_chan[!dir]->device->dev->of_node;
 		pair->dma_chan[dir] =
 			__dma_request_channel(&mask, filter, &pair->dma_data,
 					      of_dma_node);
 		pair->req_dma_chan = true;
 	} else {
 		pair->dma_chan[dir] = tmp_chan;
 		/* Do not flag to release if we are reusing the Back-End one */
 		pair->req_dma_chan = !be_chan;
 	}

 	if (!pair->dma_chan[dir]) {
 		dev_err(dev, "failed to request DMA channel for Back-End\n");
 		return -EINVAL;
 	}

 	width = snd_pcm_format_physical_width(asrc->asrc_format);
 	if (width < 8 || width > 64)
 		return -EINVAL;
 	else if (width == 8)
 		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
 	else if (width == 16)
 		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
 	else if (width == 24)
 		buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
 	else if (width <= 32)
 		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
 	else
 		buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;

 	config_be.direction = DMA_DEV_TO_DEV;
 	config_be.src_addr_width = buswidth;
 	config_be.src_maxburst = dma_params_be->maxburst;
 	config_be.dst_addr_width = buswidth;
 	config_be.dst_maxburst = dma_params_be->maxburst;

 	if (tx) {
 		config_be.src_addr = asrc->paddr + asrc->get_fifo_addr(OUT, index);
 		config_be.dst_addr = dma_params_be->addr;
 	} else {
 		config_be.dst_addr = asrc->paddr + asrc->get_fifo_addr(IN, index);
 		config_be.src_addr = dma_params_be->addr;
 	}

 	ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be);
 	if (ret) {
 		dev_err(dev, "failed to config DMA channel for Back-End\n");
 		if (pair->req_dma_chan)
 			dma_release_channel(pair->dma_chan[dir]);
 		return ret;
 	}

 	return 0;
 }

 static int fsl_asrc_dma_hw_free(struct snd_soc_component *component,
 				struct snd_pcm_substream *substream)
 {
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	u8 dir = tx ? OUT : IN;

 	if (pair->dma_chan[!dir])
 		dma_release_channel(pair->dma_chan[!dir]);

 	/* release dev_to_dev chan if we aren't reusing the Back-End one */
 	if (pair->dma_chan[dir] && pair->req_dma_chan)
 		dma_release_channel(pair->dma_chan[dir]);

 	pair->dma_chan[!dir] = NULL;
 	pair->dma_chan[dir] = NULL;

 	return 0;
 }

 static int fsl_asrc_dma_startup(struct snd_soc_component *component,
 				struct snd_pcm_substream *substream)
 {
 	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_dmaengine_dai_dma_data *dma_data;
 	struct device *dev = component->dev;
 	struct fsl_asrc *asrc = dev_get_drvdata(dev);
 	struct fsl_asrc_pair *pair;
 	struct dma_chan *tmp_chan = NULL;
 	u8 dir = tx ? OUT : IN;
 	bool release_pair = true;
 	int ret = 0;

 	ret = snd_pcm_hw_constraint_integer(substream->runtime,
 					    SNDRV_PCM_HW_PARAM_PERIODS);
 	if (ret < 0) {
 		dev_err(dev, "failed to set pcm hw params periods\n");
 		return ret;
 	}

 	pair = kzalloc(sizeof(*pair) + asrc->pair_priv_size, GFP_KERNEL);
 	if (!pair)
 		return -ENOMEM;

 	pair->asrc = asrc;
 	pair->private = (void *)pair + sizeof(struct fsl_asrc_pair);

 	runtime->private_data = pair;

 	/* Request a dummy pair, which will be released later.
 	 * Request pair function needs channel num as input, for this
 	 * dummy pair, we just request "1" channel temporarily.
 	 */
 	ret = asrc->request_pair(1, pair);
 	if (ret < 0) {
 		dev_err(dev, "failed to request asrc pair\n");
 		goto req_pair_err;
 	}

 	/* Request a dummy dma channel, which will be released later. */
 	tmp_chan = asrc->get_dma_channel(pair, dir);
 	if (!tmp_chan) {
 		dev_err(dev, "failed to get dma channel\n");
 		ret = -EINVAL;
 		goto dma_chan_err;
 	}

 	dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);

 	/* Refine the snd_imx_hardware according to caps of DMA. */
 	ret = snd_dmaengine_pcm_refine_runtime_hwparams(substream,
 							dma_data,
 							&snd_imx_hardware,
 							tmp_chan);
 	if (ret < 0) {
 		dev_err(dev, "failed to refine runtime hwparams\n");
 		goto out;
 	}

 	release_pair = false;
 	snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);

 out:
 	dma_release_channel(tmp_chan);

 dma_chan_err:
 	asrc->release_pair(pair);

 req_pair_err:
 	if (release_pair)
 		kfree(pair);

 	return ret;
 }

 static int fsl_asrc_dma_shutdown(struct snd_soc_component *component,
 				 struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;
 	struct fsl_asrc *asrc;

 	if (!pair)
 		return 0;

 	asrc = pair->asrc;

 	if (asrc->pair[pair->index] == pair)
 		asrc->pair[pair->index] = NULL;

 	kfree(pair);

 	return 0;
 }

 static snd_pcm_uframes_t
 fsl_asrc_dma_pcm_pointer(struct snd_soc_component *component,
 			 struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct fsl_asrc_pair *pair = runtime->private_data;

 	return bytes_to_frames(substream->runtime, pair->pos);
 }

 static int fsl_asrc_dma_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;
 	int ret;

 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
 	if (ret) {
 		dev_err(card->dev, "failed to set DMA mask\n");
 		return ret;
 	}

 	return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
 					    card->dev, FSL_ASRC_DMABUF_SIZE);
 }

 struct snd_soc_component_driver fsl_asrc_component = {
 	.name		= DRV_NAME,
 	.hw_params	= fsl_asrc_dma_hw_params,
 	.hw_free	= fsl_asrc_dma_hw_free,
 	.trigger	= fsl_asrc_dma_trigger,
 	.open		= fsl_asrc_dma_startup,
 	.close		= fsl_asrc_dma_shutdown,
 	.pointer	= fsl_asrc_dma_pcm_pointer,
 	.pcm_construct	= fsl_asrc_dma_pcm_new,
 };
 EXPORT_SYMBOL_GPL(fsl_asrc_component);
	// SPDX-License-Identifier: GPL-2.0
	//
	// Freescale ASRC ALSA SoC Platform (DMA) driver
	//
	// Copyright (C) 2014 Freescale Semiconductor, Inc.
	//
	// Author: Nicolin Chen <nicoleotsuka@gmail.com>

	#include <linux/dma-mapping.h>
	#include <linux/module.h>
	#include <linux/platform_data/dma-imx.h>
	#include <sound/dmaengine_pcm.h>
	#include <sound/pcm_params.h>

	#include "fsl_asrc_common.h"

	#define FSL_ASRC_DMABUF_SIZE (256 * 1024)

	static struct snd_pcm_hardware snd_imx_hardware = {
	.info = SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER \|
	SNDRV_PCM_INFO_MMAP \|
	SNDRV_PCM_INFO_MMAP_VALID,
	.buffer_bytes_max = FSL_ASRC_DMABUF_SIZE,
	.period_bytes_min = 128,
	.period_bytes_max = 65535, /* Limited by SDMA engine */
	.periods_min = 2,
	.periods_max = 255,
	.fifo_size = 0,
	};

	static bool filter(struct dma_chan chan, void param)
	{
	if (!imx_dma_is_general_purpose(chan))
	return false;

	chan->private = param;

	return true;
	}

	static void fsl_asrc_dma_complete(void *arg)
	{
	struct snd_pcm_substream *substream = arg;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct fsl_asrc_pair *pair = runtime->private_data;

	pair->pos += snd_pcm_lib_period_bytes(substream);
	if (pair->pos >= snd_pcm_lib_buffer_bytes(substream))
	pair->pos = 0;

	snd_pcm_period_elapsed(substream);
	}

	static int fsl_asrc_dma_prepare_and_submit(struct snd_pcm_substream *substream,
	struct snd_soc_component *component)
	{
	u8 dir = substream->stream == SNDRV_PCM_STREAM_PLAYBACK ? OUT : IN;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct fsl_asrc_pair *pair = runtime->private_data;
	struct device *dev = component->dev;
	unsigned long flags = DMA_CTRL_ACK;

	/* Prepare and submit Front-End DMA channel */
	if (!substream->runtime->no_period_wakeup)
	flags \|= DMA_PREP_INTERRUPT;

	pair->pos = 0;
	pair->desc[!dir] = dmaengine_prep_dma_cyclic(
	pair->dma_chan[!dir], runtime->dma_addr,
	snd_pcm_lib_buffer_bytes(substream),
	snd_pcm_lib_period_bytes(substream),
	dir == OUT ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM, flags);
	if (!pair->desc[!dir]) {
	dev_err(dev, "failed to prepare slave DMA for Front-End\n");
	return -ENOMEM;
	}

	pair->desc[!dir]->callback = fsl_asrc_dma_complete;
	pair->desc[!dir]->callback_param = substream;

	dmaengine_submit(pair->desc[!dir]);

	/* Prepare and submit Back-End DMA channel */
	pair->desc[dir] = dmaengine_prep_dma_cyclic(
	pair->dma_chan[dir], 0xffff, 64, 64, DMA_DEV_TO_DEV, 0);
	if (!pair->desc[dir]) {
	dev_err(dev, "failed to prepare slave DMA for Back-End\n");
	return -ENOMEM;
	}

	dmaengine_submit(pair->desc[dir]);

	return 0;
	}

	static int fsl_asrc_dma_trigger(struct snd_soc_component *component,
	struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct fsl_asrc_pair *pair = runtime->private_data;
	int ret;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	ret = fsl_asrc_dma_prepare_and_submit(substream, component);
	if (ret)
	return ret;
	dma_async_issue_pending(pair->dma_chan[IN]);
	dma_async_issue_pending(pair->dma_chan[OUT]);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	dmaengine_terminate_all(pair->dma_chan[OUT]);
	dmaengine_terminate_all(pair->dma_chan[IN]);
	break;
	default:
	return -EINVAL;
	}

	return 0;
	}

	static int fsl_asrc_dma_hw_params(struct snd_soc_component *component,
	struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
	{
	enum dma_slave_buswidth buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
	struct snd_dmaengine_dai_dma_data *dma_params_fe = NULL;
	struct snd_dmaengine_dai_dma_data *dma_params_be = NULL;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct fsl_asrc_pair *pair = runtime->private_data;
	struct dma_chan tmp_chan = NULL, be_chan = NULL;
	struct snd_soc_component *component_be = NULL;
	struct fsl_asrc *asrc = pair->asrc;
	struct dma_slave_config config_fe, config_be;
	enum asrc_pair_index index = pair->index;
	struct device *dev = component->dev;
	struct device_node *of_dma_node;
	int stream = substream->stream;
	struct imx_dma_data *tmp_data;
	struct snd_soc_dpcm *dpcm;
	struct device *dev_be;
	u8 dir = tx ? OUT : IN;
	dma_cap_mask_t mask;
	int ret, width;

	/* Fetch the Back-End dma_data from DPCM */
	for_each_dpcm_be(rtd, stream, dpcm) {
	struct snd_soc_pcm_runtime *be = dpcm->be;
	struct snd_pcm_substream *substream_be;
	struct snd_soc_dai *dai = asoc_rtd_to_cpu(be, 0);

	if (dpcm->fe != rtd)
	continue;

	substream_be = snd_soc_dpcm_get_substream(be, stream);
	dma_params_be = snd_soc_dai_get_dma_data(dai, substream_be);
	dev_be = dai->dev;
	break;
	}

	if (!dma_params_be) {
	dev_err(dev, "failed to get the substream of Back-End\n");
	return -EINVAL;
	}

	/* Override dma_data of the Front-End and config its dmaengine */
	dma_params_fe = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);
	dma_params_fe->addr = asrc->paddr + asrc->get_fifo_addr(!dir, index);
	dma_params_fe->maxburst = dma_params_be->maxburst;

	pair->dma_chan[!dir] = asrc->get_dma_channel(pair, !dir);
	if (!pair->dma_chan[!dir]) {
	dev_err(dev, "failed to request DMA channel\n");
	return -EINVAL;
	}

	memset(&config_fe, 0, sizeof(config_fe));
	ret = snd_dmaengine_pcm_prepare_slave_config(substream, params, &config_fe);
	if (ret) {
	dev_err(dev, "failed to prepare DMA config for Front-End\n");
	return ret;
	}

	ret = dmaengine_slave_config(pair->dma_chan[!dir], &config_fe);
	if (ret) {
	dev_err(dev, "failed to config DMA channel for Front-End\n");
	return ret;
	}

	/* Request and config DMA channel for Back-End */
	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);
	dma_cap_set(DMA_CYCLIC, mask);

	/*
	* The Back-End device might have already requested a DMA channel,
	* so try to reuse it first, and then request a new one upon NULL.
	*/
	component_be = snd_soc_lookup_component_nolocked(dev_be, SND_DMAENGINE_PCM_DRV_NAME);
	if (component_be) {
	be_chan = soc_component_to_pcm(component_be)->chan[substream->stream];
	tmp_chan = be_chan;
	}
	if (!tmp_chan)
	tmp_chan = dma_request_slave_channel(dev_be, tx ? "tx" : "rx");

	/*
	* An EDMA DEV_TO_DEV channel is fixed and bound with DMA event of each
	* peripheral, unlike SDMA channel that is allocated dynamically. So no
	* need to configure dma_request and dma_request2, but get dma_chan of
	* Back-End device directly via dma_request_slave_channel.
	*/
	if (!asrc->use_edma) {
	/* Get DMA request of Back-End */
	tmp_data = tmp_chan->private;
	pair->dma_data.dma_request = tmp_data->dma_request;
	if (!be_chan)
	dma_release_channel(tmp_chan);

	/* Get DMA request of Front-End */
	tmp_chan = asrc->get_dma_channel(pair, dir);
	tmp_data = tmp_chan->private;
	pair->dma_data.dma_request2 = tmp_data->dma_request;
	pair->dma_data.peripheral_type = tmp_data->peripheral_type;
	pair->dma_data.priority = tmp_data->priority;
	dma_release_channel(tmp_chan);

	of_dma_node = pair->dma_chan[!dir]->device->dev->of_node;
	pair->dma_chan[dir] =
	__dma_request_channel(&mask, filter, &pair->dma_data,
	of_dma_node);
	pair->req_dma_chan = true;
	} else {
	pair->dma_chan[dir] = tmp_chan;
	/* Do not flag to release if we are reusing the Back-End one */
	pair->req_dma_chan = !be_chan;
	}

	if (!pair->dma_chan[dir]) {
	dev_err(dev, "failed to request DMA channel for Back-End\n");
	return -EINVAL;
	}

	width = snd_pcm_format_physical_width(asrc->asrc_format);
	if (width < 8 \|\| width > 64)
	return -EINVAL;
	else if (width == 8)
	buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
	else if (width == 16)
	buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
	else if (width == 24)
	buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES;
	else if (width <= 32)
	buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
	else
	buswidth = DMA_SLAVE_BUSWIDTH_8_BYTES;

	config_be.direction = DMA_DEV_TO_DEV;
	config_be.src_addr_width = buswidth;
	config_be.src_maxburst = dma_params_be->maxburst;
	config_be.dst_addr_width = buswidth;
	config_be.dst_maxburst = dma_params_be->maxburst;

	if (tx) {
	config_be.src_addr = asrc->paddr + asrc->get_fifo_addr(OUT, index);
	config_be.dst_addr = dma_params_be->addr;
	} else {
	config_be.dst_addr = asrc->paddr + asrc->get_fifo_addr(IN, index);
	config_be.src_addr = dma_params_be->addr;
	}

	ret = dmaengine_slave_config(pair->dma_chan[dir], &config_be);
	if (ret) {
	dev_err(dev, "failed to config DMA channel for Back-End\n");
	if (pair->req_dma_chan)
	dma_release_channel(pair->dma_chan[dir]);
	return ret;
	}

	return 0;
	}

	static int fsl_asrc_dma_hw_free(struct snd_soc_component *component,
	struct snd_pcm_substream *substream)
	{
	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct fsl_asrc_pair *pair = runtime->private_data;
	u8 dir = tx ? OUT : IN;

	if (pair->dma_chan[!dir])
	dma_release_channel(pair->dma_chan[!dir]);

	/* release dev_to_dev chan if we aren't reusing the Back-End one */
	if (pair->dma_chan[dir] && pair->req_dma_chan)
	dma_release_channel(pair->dma_chan[dir]);

	pair->dma_chan[!dir] = NULL;
	pair->dma_chan[dir] = NULL;

	return 0;
	}

	static int fsl_asrc_dma_startup(struct snd_soc_component *component,
	struct snd_pcm_substream *substream)
	{
	bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
	struct snd_soc_pcm_runtime *rtd = asoc_substream_to_rtd(substream);
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_dmaengine_dai_dma_data *dma_data;
	struct device *dev = component->dev;
	struct fsl_asrc *asrc = dev_get_drvdata(dev);
	struct fsl_asrc_pair *pair;
	struct dma_chan *tmp_chan = NULL;
	u8 dir = tx ? OUT : IN;
	bool release_pair = true;
	int ret = 0;

	ret = snd_pcm_hw_constraint_integer(substream->runtime,
	SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0) {
	dev_err(dev, "failed to set pcm hw params periods\n");
	return ret;
	}

	pair = kzalloc(sizeof(*pair) + asrc->pair_priv_size, GFP_KERNEL);
	if (!pair)
	return -ENOMEM;

	pair->asrc = asrc;
	pair->private = (void *)pair + sizeof(struct fsl_asrc_pair);

	runtime->private_data = pair;

	/* Request a dummy pair, which will be released later.
	* Request pair function needs channel num as input, for this
	* dummy pair, we just request "1" channel temporarily.
	*/
	ret = asrc->request_pair(1, pair);
	if (ret < 0) {
	dev_err(dev, "failed to request asrc pair\n");
	goto req_pair_err;
	}

	/* Request a dummy dma channel, which will be released later. */
	tmp_chan = asrc->get_dma_channel(pair, dir);
	if (!tmp_chan) {
	dev_err(dev, "failed to get dma channel\n");
	ret = -EINVAL;
	goto dma_chan_err;
	}

	dma_data = snd_soc_dai_get_dma_data(asoc_rtd_to_cpu(rtd, 0), substream);

	/* Refine the snd_imx_hardware according to caps of DMA. */
	ret = snd_dmaengine_pcm_refine_runtime_hwparams(substream,
	dma_data,
	&snd_imx_hardware,
	tmp_chan);
	if (ret < 0) {
	dev_err(dev, "failed to refine runtime hwparams\n");
	goto out;
	}

	release_pair = false;
	snd_soc_set_runtime_hwparams(substream, &snd_imx_hardware);

	out:
	dma_release_channel(tmp_chan);

	dma_chan_err:
	asrc->release_pair(pair);

	req_pair_err:
	if (release_pair)
	kfree(pair);

	return ret;
	}

	static int fsl_asrc_dma_shutdown(struct snd_soc_component *component,
	struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct fsl_asrc_pair *pair = runtime->private_data;
	struct fsl_asrc *asrc;

	if (!pair)
	return 0;

	asrc = pair->asrc;

	if (asrc->pair[pair->index] == pair)
	asrc->pair[pair->index] = NULL;

	kfree(pair);

	return 0;
	}

	static snd_pcm_uframes_t
	fsl_asrc_dma_pcm_pointer(struct snd_soc_component *component,
	struct snd_pcm_substream *substream)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct fsl_asrc_pair *pair = runtime->private_data;

	return bytes_to_frames(substream->runtime, pair->pos);
	}

	static int fsl_asrc_dma_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;
	int ret;

	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
	if (ret) {
	dev_err(card->dev, "failed to set DMA mask\n");
	return ret;
	}

	return snd_pcm_set_fixed_buffer_all(pcm, SNDRV_DMA_TYPE_DEV,
	card->dev, FSL_ASRC_DMABUF_SIZE);
	}

	struct snd_soc_component_driver fsl_asrc_component = {
	.name = DRV_NAME,
	.hw_params = fsl_asrc_dma_hw_params,
	.hw_free = fsl_asrc_dma_hw_free,
	.trigger = fsl_asrc_dma_trigger,
	.open = fsl_asrc_dma_startup,
	.close = fsl_asrc_dma_shutdown,
	.pointer = fsl_asrc_dma_pcm_pointer,
	.pcm_construct = fsl_asrc_dma_pcm_new,
	};
	EXPORT_SYMBOL_GPL(fsl_asrc_component);