sound/soc/blackfin/bf5xx-i2s-pcm.c - kernel/lockdown - Git at Google

 /*
  * File:         sound/soc/blackfin/bf5xx-i2s-pcm.c
  * Author:       Cliff Cai <Cliff.Cai@analog.com>
  *
  * Created:      Tue June 06 2008
  * Description:  DMA driver for i2s codec
  *
  * Modified:
  *               Copyright 2008 Analog Devices Inc.
  *
  * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, see the file COPYING, or write
  * to the Free Software Foundation, Inc.,
  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */

 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/platform_device.h>
 #include <linux/dma-mapping.h>
 #include <linux/gfp.h>

 #include <sound/core.h>
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>

 #include <asm/dma.h>

 #include "bf5xx-sport.h"
 #include "bf5xx-i2s-pcm.h"

 static void bf5xx_dma_irq(void *data)
 {
 	struct snd_pcm_substream *pcm = data;
 	snd_pcm_period_elapsed(pcm);
 }

 static const struct snd_pcm_hardware bf5xx_pcm_hardware = {
 	.info			= SNDRV_PCM_INFO_INTERLEAVED |
 				   SNDRV_PCM_INFO_MMAP_VALID |
 				   SNDRV_PCM_INFO_BLOCK_TRANSFER,
 	.period_bytes_min	= 32,
 	.period_bytes_max	= 0x10000,
 	.periods_min		= 1,
 	.periods_max		= PAGE_SIZE/32,
 	.buffer_bytes_max	= 0x20000, /* 128 kbytes */
 	.fifo_size		= 16,
 };

 static int bf5xx_pcm_hw_params(struct snd_pcm_substream *substream,
 	struct snd_pcm_hw_params *params)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	unsigned int buffer_size = params_buffer_bytes(params);
 	struct bf5xx_i2s_pcm_data *dma_data;

 	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

 	if (dma_data->tdm_mode)
 		buffer_size = buffer_size / params_channels(params) * 8;

 	return snd_pcm_lib_malloc_pages(substream, buffer_size);
 }

 static int bf5xx_pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	snd_pcm_lib_free_pages(substream);

 	return 0;
 }

 static int bf5xx_pcm_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct sport_device *sport = runtime->private_data;
 	int period_bytes = frames_to_bytes(runtime, runtime->period_size);
 	struct bf5xx_i2s_pcm_data *dma_data;

 	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

 	if (dma_data->tdm_mode)
 		period_bytes = period_bytes / runtime->channels * 8;

 	pr_debug("%s enter\n", __func__);
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		sport_set_tx_callback(sport, bf5xx_dma_irq, substream);
 		sport_config_tx_dma(sport, runtime->dma_area,
 			runtime->periods, period_bytes);
 	} else {
 		sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
 		sport_config_rx_dma(sport, runtime->dma_area,
 			runtime->periods, period_bytes);
 	}

 	return 0;
 }

 static int bf5xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct sport_device *sport = runtime->private_data;
 	int ret = 0;

 	pr_debug("%s enter\n", __func__);
 	switch (cmd) {
 	case SNDRV_PCM_TRIGGER_START:
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			sport_tx_start(sport);
 		else
 			sport_rx_start(sport);
 		break;
 	case SNDRV_PCM_TRIGGER_STOP:
 	case SNDRV_PCM_TRIGGER_SUSPEND:
 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			sport_tx_stop(sport);
 		else
 			sport_rx_stop(sport);
 		break;
 	default:
 		ret = -EINVAL;
 	}

 	return ret;
 }

 static snd_pcm_uframes_t bf5xx_pcm_pointer(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct sport_device *sport = runtime->private_data;
 	unsigned int diff;
 	snd_pcm_uframes_t frames;
 	struct bf5xx_i2s_pcm_data *dma_data;

 	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

 	pr_debug("%s enter\n", __func__);
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		diff = sport_curr_offset_tx(sport);
 	} else {
 		diff = sport_curr_offset_rx(sport);
 	}

 	/*
 	 * TX at least can report one frame beyond the end of the
 	 * buffer if we hit the wraparound case - clamp to within the
 	 * buffer as the ALSA APIs require.
 	 */
 	if (diff == snd_pcm_lib_buffer_bytes(substream))
 		diff = 0;

 	frames = bytes_to_frames(substream->runtime, diff);
 	if (dma_data->tdm_mode)
 		frames = frames * runtime->channels / 8;

 	return frames;
 }

 static int bf5xx_pcm_open(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	struct sport_device *sport_handle = snd_soc_dai_get_drvdata(cpu_dai);
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_dma_buffer *buf = &substream->dma_buffer;
 	struct bf5xx_i2s_pcm_data *dma_data;
 	int ret;

 	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

 	pr_debug("%s enter\n", __func__);

 	snd_soc_set_runtime_hwparams(substream, &bf5xx_pcm_hardware);
 	if (dma_data->tdm_mode)
 		runtime->hw.buffer_bytes_max /= 4;
 	else
 		runtime->hw.info |= SNDRV_PCM_INFO_MMAP;

 	ret = snd_pcm_hw_constraint_integer(runtime,
 			SNDRV_PCM_HW_PARAM_PERIODS);
 	if (ret < 0)
 		goto out;

 	if (sport_handle != NULL) {
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 			sport_handle->tx_buf = buf->area;
 		else
 			sport_handle->rx_buf = buf->area;

 		runtime->private_data = sport_handle;
 	} else {
 		pr_err("sport_handle is NULL\n");
 		return -1;
 	}
 	return 0;

  out:
 	return ret;
 }

 static int bf5xx_pcm_mmap(struct snd_pcm_substream *substream,
 	struct vm_area_struct *vma)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	size_t size = vma->vm_end - vma->vm_start;
 	vma->vm_start = (unsigned long)runtime->dma_area;
 	vma->vm_end = vma->vm_start + size;
 	vma->vm_flags |=  VM_SHARED;

 	return 0 ;
 }

 static int bf5xx_pcm_copy(struct snd_pcm_substream *substream, int channel,
 	snd_pcm_uframes_t pos, void *buf, snd_pcm_uframes_t count)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	unsigned int sample_size = runtime->sample_bits / 8;
 	struct bf5xx_i2s_pcm_data *dma_data;
 	unsigned int i;
 	void *src, *dst;

 	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

 	if (dma_data->tdm_mode) {
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			src = buf;
 			dst = runtime->dma_area;
 			dst += pos * sample_size * 8;

 			while (count--) {
 				for (i = 0; i < runtime->channels; i++) {
 					memcpy(dst + dma_data->map[i] *
 						sample_size, src, sample_size);
 					src += sample_size;
 				}
 				dst += 8 * sample_size;
 			}
 		} else {
 			src = runtime->dma_area;
 			src += pos * sample_size * 8;
 			dst = buf;

 			while (count--) {
 				for (i = 0; i < runtime->channels; i++) {
 					memcpy(dst, src + dma_data->map[i] *
 						sample_size, sample_size);
 					dst += sample_size;
 				}
 				src += 8 * sample_size;
 			}
 		}
 	} else {
 		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 			src = buf;
 			dst = runtime->dma_area;
 			dst += frames_to_bytes(runtime, pos);
 		} else {
 			src = runtime->dma_area;
 			src += frames_to_bytes(runtime, pos);
 			dst = buf;
 		}

 		memcpy(dst, src, frames_to_bytes(runtime, count));
 	}

 	return 0;
 }

 static int bf5xx_pcm_silence(struct snd_pcm_substream *substream,
 	int channel, snd_pcm_uframes_t pos, snd_pcm_uframes_t count)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	unsigned int sample_size = runtime->sample_bits / 8;
 	void *buf = runtime->dma_area;
 	struct bf5xx_i2s_pcm_data *dma_data;
 	unsigned int offset, samples;

 	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

 	if (dma_data->tdm_mode) {
 		offset = pos * 8 * sample_size;
 		samples = count * 8;
 	} else {
 		offset = frames_to_bytes(runtime, pos);
 		samples = count * runtime->channels;
 	}

 	snd_pcm_format_set_silence(runtime->format, buf + offset, samples);

 	return 0;
 }

 static struct snd_pcm_ops bf5xx_pcm_i2s_ops = {
 	.open		= bf5xx_pcm_open,
 	.ioctl		= snd_pcm_lib_ioctl,
 	.hw_params	= bf5xx_pcm_hw_params,
 	.hw_free	= bf5xx_pcm_hw_free,
 	.prepare	= bf5xx_pcm_prepare,
 	.trigger	= bf5xx_pcm_trigger,
 	.pointer	= bf5xx_pcm_pointer,
 	.mmap		= bf5xx_pcm_mmap,
 	.copy		= bf5xx_pcm_copy,
 	.silence	= bf5xx_pcm_silence,
 };

 static int bf5xx_pcm_i2s_new(struct snd_soc_pcm_runtime *rtd)
 {
 	struct snd_card *card = rtd->card->snd_card;
 	size_t size = bf5xx_pcm_hardware.buffer_bytes_max;
 	int ret;

 	pr_debug("%s enter\n", __func__);
 	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
 	if (ret)
 		return ret;

 	return snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
 				SNDRV_DMA_TYPE_DEV, card->dev, size, size);
 }

 static struct snd_soc_platform_driver bf5xx_i2s_soc_platform = {
 	.ops		= &bf5xx_pcm_i2s_ops,
 	.pcm_new	= bf5xx_pcm_i2s_new,
 };

 static int bfin_i2s_soc_platform_probe(struct platform_device *pdev)
 {
 	return snd_soc_register_platform(&pdev->dev, &bf5xx_i2s_soc_platform);
 }

 static int bfin_i2s_soc_platform_remove(struct platform_device *pdev)
 {
 	snd_soc_unregister_platform(&pdev->dev);
 	return 0;
 }

 static struct platform_driver bfin_i2s_pcm_driver = {
 	.driver = {
 		.name = "bfin-i2s-pcm-audio",
 		.owner = THIS_MODULE,
 	},

 	.probe = bfin_i2s_soc_platform_probe,
 	.remove = bfin_i2s_soc_platform_remove,
 };

 module_platform_driver(bfin_i2s_pcm_driver);

 MODULE_AUTHOR("Cliff Cai");
 MODULE_DESCRIPTION("ADI Blackfin I2S PCM DMA module");
 MODULE_LICENSE("GPL");
	/*
	* File: sound/soc/blackfin/bf5xx-i2s-pcm.c
	* Author: Cliff Cai <Cliff.Cai@analog.com>
	*
	* Created: Tue June 06 2008
	* Description: DMA driver for i2s codec
	*
	* Modified:
	* Copyright 2008 Analog Devices Inc.
	*
	* Bugs: Enter bugs at http://blackfin.uclinux.org/
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, see the file COPYING, or write
	* to the Free Software Foundation, Inc.,
	* 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#include <linux/module.h>
	#include <linux/init.h>
	#include <linux/platform_device.h>
	#include <linux/dma-mapping.h>
	#include <linux/gfp.h>

	#include <sound/core.h>
	#include <sound/pcm.h>
	#include <sound/pcm_params.h>
	#include <sound/soc.h>

	#include <asm/dma.h>

	#include "bf5xx-sport.h"
	#include "bf5xx-i2s-pcm.h"

	static void bf5xx_dma_irq(void *data)
	{
	struct snd_pcm_substream *pcm = data;
	snd_pcm_period_elapsed(pcm);
	}

	static const struct snd_pcm_hardware bf5xx_pcm_hardware = {
	.info = SNDRV_PCM_INFO_INTERLEAVED \|
	SNDRV_PCM_INFO_MMAP_VALID \|
	SNDRV_PCM_INFO_BLOCK_TRANSFER,
	.period_bytes_min = 32,
	.period_bytes_max = 0x10000,
	.periods_min = 1,
	.periods_max = PAGE_SIZE/32,
	.buffer_bytes_max = 0x20000, /* 128 kbytes */
	.fifo_size = 16,
	};

	static int bf5xx_pcm_hw_params(struct snd_pcm_substream *substream,
	struct snd_pcm_hw_params *params)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	unsigned int buffer_size = params_buffer_bytes(params);
	struct bf5xx_i2s_pcm_data *dma_data;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	if (dma_data->tdm_mode)
	buffer_size = buffer_size / params_channels(params) * 8;

	return snd_pcm_lib_malloc_pages(substream, buffer_size);
	}

	static int bf5xx_pcm_hw_free(struct snd_pcm_substream *substream)
	{
	snd_pcm_lib_free_pages(substream);

	return 0;
	}

	static int bf5xx_pcm_prepare(struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;
	int period_bytes = frames_to_bytes(runtime, runtime->period_size);
	struct bf5xx_i2s_pcm_data *dma_data;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	if (dma_data->tdm_mode)
	period_bytes = period_bytes / runtime->channels * 8;

	pr_debug("%s enter\n", __func__);
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	sport_set_tx_callback(sport, bf5xx_dma_irq, substream);
	sport_config_tx_dma(sport, runtime->dma_area,
	runtime->periods, period_bytes);
	} else {
	sport_set_rx_callback(sport, bf5xx_dma_irq, substream);
	sport_config_rx_dma(sport, runtime->dma_area,
	runtime->periods, period_bytes);
	}

	return 0;
	}

	static int bf5xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;
	int ret = 0;

	pr_debug("%s enter\n", __func__);
	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	sport_tx_start(sport);
	else
	sport_rx_start(sport);
	break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	sport_tx_stop(sport);
	else
	sport_rx_stop(sport);
	break;
	default:
	ret = -EINVAL;
	}

	return ret;
	}

	static snd_pcm_uframes_t bf5xx_pcm_pointer(struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct sport_device *sport = runtime->private_data;
	unsigned int diff;
	snd_pcm_uframes_t frames;
	struct bf5xx_i2s_pcm_data *dma_data;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	pr_debug("%s enter\n", __func__);
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	diff = sport_curr_offset_tx(sport);
	} else {
	diff = sport_curr_offset_rx(sport);
	}

	/*
	* TX at least can report one frame beyond the end of the
	* buffer if we hit the wraparound case - clamp to within the
	* buffer as the ALSA APIs require.
	*/
	if (diff == snd_pcm_lib_buffer_bytes(substream))
	diff = 0;

	frames = bytes_to_frames(substream->runtime, diff);
	if (dma_data->tdm_mode)
	frames = frames * runtime->channels / 8;

	return frames;
	}

	static int bf5xx_pcm_open(struct snd_pcm_substream *substream)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
	struct sport_device *sport_handle = snd_soc_dai_get_drvdata(cpu_dai);
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct snd_dma_buffer *buf = &substream->dma_buffer;
	struct bf5xx_i2s_pcm_data *dma_data;
	int ret;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	pr_debug("%s enter\n", __func__);

	snd_soc_set_runtime_hwparams(substream, &bf5xx_pcm_hardware);
	if (dma_data->tdm_mode)
	runtime->hw.buffer_bytes_max /= 4;
	else
	runtime->hw.info \|= SNDRV_PCM_INFO_MMAP;

	ret = snd_pcm_hw_constraint_integer(runtime,
	SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
	goto out;

	if (sport_handle != NULL) {
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
	sport_handle->tx_buf = buf->area;
	else
	sport_handle->rx_buf = buf->area;

	runtime->private_data = sport_handle;
	} else {
	pr_err("sport_handle is NULL\n");
	return -1;
	}
	return 0;

	out:
	return ret;
	}

	static int bf5xx_pcm_mmap(struct snd_pcm_substream *substream,
	struct vm_area_struct *vma)
	{
	struct snd_pcm_runtime *runtime = substream->runtime;
	size_t size = vma->vm_end - vma->vm_start;
	vma->vm_start = (unsigned long)runtime->dma_area;
	vma->vm_end = vma->vm_start + size;
	vma->vm_flags \|= VM_SHARED;

	return 0 ;
	}

	static int bf5xx_pcm_copy(struct snd_pcm_substream *substream, int channel,
	snd_pcm_uframes_t pos, void *buf, snd_pcm_uframes_t count)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	unsigned int sample_size = runtime->sample_bits / 8;
	struct bf5xx_i2s_pcm_data *dma_data;
	unsigned int i;
	void src, dst;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	if (dma_data->tdm_mode) {
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	src = buf;
	dst = runtime->dma_area;
	dst += pos * sample_size * 8;

	while (count--) {
	for (i = 0; i < runtime->channels; i++) {
	memcpy(dst + dma_data->map[i] *
	sample_size, src, sample_size);
	src += sample_size;
	}
	dst += 8 * sample_size;
	}
	} else {
	src = runtime->dma_area;
	src += pos * sample_size * 8;
	dst = buf;

	while (count--) {
	for (i = 0; i < runtime->channels; i++) {
	memcpy(dst, src + dma_data->map[i] *
	sample_size, sample_size);
	dst += sample_size;
	}
	src += 8 * sample_size;
	}
	}
	} else {
	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	src = buf;
	dst = runtime->dma_area;
	dst += frames_to_bytes(runtime, pos);
	} else {
	src = runtime->dma_area;
	src += frames_to_bytes(runtime, pos);
	dst = buf;
	}

	memcpy(dst, src, frames_to_bytes(runtime, count));
	}

	return 0;
	}

	static int bf5xx_pcm_silence(struct snd_pcm_substream *substream,
	int channel, snd_pcm_uframes_t pos, snd_pcm_uframes_t count)
	{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct snd_pcm_runtime *runtime = substream->runtime;
	unsigned int sample_size = runtime->sample_bits / 8;
	void *buf = runtime->dma_area;
	struct bf5xx_i2s_pcm_data *dma_data;
	unsigned int offset, samples;

	dma_data = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);

	if (dma_data->tdm_mode) {
	offset = pos * 8 * sample_size;
	samples = count * 8;
	} else {
	offset = frames_to_bytes(runtime, pos);
	samples = count * runtime->channels;
	}

	snd_pcm_format_set_silence(runtime->format, buf + offset, samples);

	return 0;
	}

	static struct snd_pcm_ops bf5xx_pcm_i2s_ops = {
	.open = bf5xx_pcm_open,
	.ioctl = snd_pcm_lib_ioctl,
	.hw_params = bf5xx_pcm_hw_params,
	.hw_free = bf5xx_pcm_hw_free,
	.prepare = bf5xx_pcm_prepare,
	.trigger = bf5xx_pcm_trigger,
	.pointer = bf5xx_pcm_pointer,
	.mmap = bf5xx_pcm_mmap,
	.copy = bf5xx_pcm_copy,
	.silence = bf5xx_pcm_silence,
	};

	static int bf5xx_pcm_i2s_new(struct snd_soc_pcm_runtime *rtd)
	{
	struct snd_card *card = rtd->card->snd_card;
	size_t size = bf5xx_pcm_hardware.buffer_bytes_max;
	int ret;

	pr_debug("%s enter\n", __func__);
	ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
	if (ret)
	return ret;

	return snd_pcm_lib_preallocate_pages_for_all(rtd->pcm,
	SNDRV_DMA_TYPE_DEV, card->dev, size, size);
	}

	static struct snd_soc_platform_driver bf5xx_i2s_soc_platform = {
	.ops = &bf5xx_pcm_i2s_ops,
	.pcm_new = bf5xx_pcm_i2s_new,
	};

	static int bfin_i2s_soc_platform_probe(struct platform_device *pdev)
	{
	return snd_soc_register_platform(&pdev->dev, &bf5xx_i2s_soc_platform);
	}

	static int bfin_i2s_soc_platform_remove(struct platform_device *pdev)
	{
	snd_soc_unregister_platform(&pdev->dev);
	return 0;
	}

	static struct platform_driver bfin_i2s_pcm_driver = {
	.driver = {
	.name = "bfin-i2s-pcm-audio",
	.owner = THIS_MODULE,
	},

	.probe = bfin_i2s_soc_platform_probe,
	.remove = bfin_i2s_soc_platform_remove,
	};

	module_platform_driver(bfin_i2s_pcm_driver);

	MODULE_AUTHOR("Cliff Cai");
	MODULE_DESCRIPTION("ADI Blackfin I2S PCM DMA module");
	MODULE_LICENSE("GPL");