[linux-2.6-block.git] / sound / arm / pxa2xx-pcm-lib.c

/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/slab.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>

#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/pxa2xx-lib.h>
#include <sound/dmaengine_pcm.h>

#include <mach/dma.h>

#include "pxa2xx-pcm.h"

static const struct snd_pcm_hardware pxa2xx_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 |
					SNDRV_PCM_FMTBIT_S32_LE,
	.period_bytes_min	= 32,
	.period_bytes_max	= 8192 - 32,
	.periods_min		= 1,
	.periods_max		= PAGE_SIZE/sizeof(pxa_dma_desc),
	.buffer_bytes_max	= 128 * 1024,
	.fifo_size		= 32,
};

int __pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct pxa2xx_runtime_data *rtd = runtime->private_data;
	size_t totsize = params_buffer_bytes(params);
	size_t period = params_period_bytes(params);
	pxa_dma_desc *dma_desc;
	dma_addr_t dma_buff_phys, next_desc_phys;
	u32 dcmd = DCMD_INCSRCADDR | DCMD_FLOWTRG;

	/* temporary transition hack */
	switch (rtd->params->addr_width) {
	case DMA_SLAVE_BUSWIDTH_1_BYTE:
		dcmd |= DCMD_WIDTH1;
		break;
	case DMA_SLAVE_BUSWIDTH_2_BYTES:
		dcmd |= DCMD_WIDTH2;
		break;
	case DMA_SLAVE_BUSWIDTH_4_BYTES:
		dcmd |= DCMD_WIDTH4;
		break;
	default:
		/* can't happen */
		break;
	}

	switch (rtd->params->maxburst) {
	case 8:
		dcmd |= DCMD_BURST8;
		break;
	case 16:
		dcmd |= DCMD_BURST16;
		break;
	case 32:
		dcmd |= DCMD_BURST32;
		break;
	}

	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
	runtime->dma_bytes = totsize;

	dma_desc = rtd->dma_desc_array;
	next_desc_phys = rtd->dma_desc_array_phys;
	dma_buff_phys = runtime->dma_addr;
	do {
		next_desc_phys += sizeof(pxa_dma_desc);
		dma_desc->ddadr = next_desc_phys;
		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
			dma_desc->dsadr = dma_buff_phys;
			dma_desc->dtadr = rtd->params->addr;
		} else {
			dma_desc->dsadr = rtd->params->addr;
			dma_desc->dtadr = dma_buff_phys;
		}
		if (period > totsize)
			period = totsize;
		dma_desc->dcmd = dcmd | period | DCMD_ENDIRQEN;
		dma_desc++;
		dma_buff_phys += period;
	} while (totsize -= period);
	dma_desc[-1].ddadr = rtd->dma_desc_array_phys;

	return 0;
}
EXPORT_SYMBOL(__pxa2xx_pcm_hw_params);

int __pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
{
	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;

	if (rtd && rtd->params && rtd->params->filter_data) {
		unsigned long req = *(unsigned long *) rtd->params->filter_data;
		DRCMR(req) = 0;
	}

	snd_pcm_set_runtime_buffer(substream, NULL);
	return 0;
}
EXPORT_SYMBOL(__pxa2xx_pcm_hw_free);

int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
	int ret = 0;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
		DCSR(prtd->dma_ch) = DCSR_RUN;
		break;

	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		DCSR(prtd->dma_ch) &= ~DCSR_RUN;
		break;

	case SNDRV_PCM_TRIGGER_RESUME:
		DCSR(prtd->dma_ch) |= DCSR_RUN;
		break;
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
		DCSR(prtd->dma_ch) |= DCSR_RUN;
		break;

	default:
		ret = -EINVAL;
	}

	return ret;
}
EXPORT_SYMBOL(pxa2xx_pcm_trigger);

snd_pcm_uframes_t
pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct pxa2xx_runtime_data *prtd = runtime->private_data;

	dma_addr_t ptr = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
			 DSADR(prtd->dma_ch) : DTADR(prtd->dma_ch);
	snd_pcm_uframes_t x = bytes_to_frames(runtime, ptr - runtime->dma_addr);

	if (x == runtime->buffer_size)
		x = 0;
	return x;
}
EXPORT_SYMBOL(pxa2xx_pcm_pointer);

int __pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
{
	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
	unsigned long req;

	if (!prtd || !prtd->params)
		return 0;

	if (prtd->dma_ch == -1)
		return -EINVAL;

	DCSR(prtd->dma_ch) &= ~DCSR_RUN;
	DCSR(prtd->dma_ch) = 0;
	DCMD(prtd->dma_ch) = 0;
	req = *(unsigned long *) prtd->params->filter_data;
	DRCMR(req) = prtd->dma_ch | DRCMR_MAPVLD;

	return 0;
}
EXPORT_SYMBOL(__pxa2xx_pcm_prepare);

void pxa2xx_pcm_dma_irq(int dma_ch, void *dev_id)
{
	struct snd_pcm_substream *substream = dev_id;
	int dcsr;

	dcsr = DCSR(dma_ch);
	DCSR(dma_ch) = dcsr & ~DCSR_STOPIRQEN;

	if (dcsr & DCSR_ENDINTR) {
		snd_pcm_period_elapsed(substream);
	} else {
		printk(KERN_ERR "DMA error on channel %d (DCSR=%#x)\n",
			dma_ch, dcsr);
		snd_pcm_stream_lock(substream);
		snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
		snd_pcm_stream_unlock(substream);
	}
}
EXPORT_SYMBOL(pxa2xx_pcm_dma_irq);

int __pxa2xx_pcm_open(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct pxa2xx_runtime_data *rtd;
	int ret;

	runtime->hw = pxa2xx_pcm_hardware;

	/*
	 * For mysterious reasons (and despite what the manual says)
	 * playback samples are lost if the DMA count is not a multiple
	 * of the DMA burst size.  Let's add a rule to enforce that.
	 */
	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
	if (ret)
		goto out;

	ret = snd_pcm_hw_constraint_step(runtime, 0,
		SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
	if (ret)
		goto out;

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

	ret = -ENOMEM;
	rtd = kzalloc(sizeof(*rtd), GFP_KERNEL);
	if (!rtd)
		goto out;
	rtd->dma_desc_array =
		dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
				       &rtd->dma_desc_array_phys, GFP_KERNEL);
	if (!rtd->dma_desc_array)
		goto err1;

	rtd->dma_ch = -1;
	runtime->private_data = rtd;
	return 0;

 err1:
	kfree(rtd);
 out:
	return ret;
}
EXPORT_SYMBOL(__pxa2xx_pcm_open);

int __pxa2xx_pcm_close(struct snd_pcm_substream *substream)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	struct pxa2xx_runtime_data *rtd = runtime->private_data;

	dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
			      rtd->dma_desc_array, rtd->dma_desc_array_phys);
	kfree(rtd);
	return 0;
}
EXPORT_SYMBOL(__pxa2xx_pcm_close);

int pxa2xx_pcm_mmap(struct snd_pcm_substream *substream,
	struct vm_area_struct *vma)
{
	struct snd_pcm_runtime *runtime = substream->runtime;
	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
				     runtime->dma_area,
				     runtime->dma_addr,
				     runtime->dma_bytes);
}
EXPORT_SYMBOL(pxa2xx_pcm_mmap);

int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
{
	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
	struct snd_dma_buffer *buf = &substream->dma_buffer;
	size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;
	buf->dev.type = SNDRV_DMA_TYPE_DEV;
	buf->dev.dev = pcm->card->dev;
	buf->private_data = NULL;
	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
					   &buf->addr, GFP_KERNEL);
	if (!buf->area)
		return -ENOMEM;
	buf->bytes = size;
	return 0;
}
EXPORT_SYMBOL(pxa2xx_pcm_preallocate_dma_buffer);

void pxa2xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
{
	struct snd_pcm_substream *substream;
	struct snd_dma_buffer *buf;
	int stream;

	for (stream = 0; stream < 2; stream++) {
		substream = pcm->streams[stream].substream;
		if (!substream)
			continue;
		buf = &substream->dma_buffer;
		if (!buf->area)
			continue;
		dma_free_writecombine(pcm->card->dev, buf->bytes,
				      buf->area, buf->addr);
		buf->area = NULL;
	}
}
EXPORT_SYMBOL(pxa2xx_pcm_free_dma_buffers);

MODULE_AUTHOR("Nicolas Pitre");
MODULE_DESCRIPTION("Intel PXA2xx sound library");
MODULE_LICENSE("GPL");
Commit	Line	Data
a6d77317 DB	1	/*
	2	* This program is free software; you can redistribute it and/or modify
	3	* it under the terms of the GNU General Public License version 2 as
	4	* published by the Free Software Foundation.
	5	*/
	6
5a0e3ad6	7	#include <linux/slab.h>
a6d77317 DB	8	#include <linux/module.h>
a6d77317 DB	9	#include <linux/dma-mapping.h>
d65a1458	10	#include <linux/dmaengine.h>
a6d77317 DB	11
	12	#include <sound/core.h>
	13	#include <sound/pcm.h>
	14	#include <sound/pcm_params.h>
	15	#include <sound/pxa2xx-lib.h>
d65a1458	16	#include <sound/dmaengine_pcm.h>
a6d77317	17
5742964e	18	#include <mach/dma.h>
a6d77317 DB	19
	20	#include "pxa2xx-pcm.h"
	21
	22	static const struct snd_pcm_hardware pxa2xx_pcm_hardware = {
	23	.info = SNDRV_PCM_INFO_MMAP \|
	24	SNDRV_PCM_INFO_MMAP_VALID \|
	25	SNDRV_PCM_INFO_INTERLEAVED \|
	26	SNDRV_PCM_INFO_PAUSE \|
	27	SNDRV_PCM_INFO_RESUME,
	28	.formats = SNDRV_PCM_FMTBIT_S16_LE \|
	29	SNDRV_PCM_FMTBIT_S24_LE \|
	30	SNDRV_PCM_FMTBIT_S32_LE,
	31	.period_bytes_min = 32,
	32	.period_bytes_max = 8192 - 32,
	33	.periods_min = 1,
	34	.periods_max = PAGE_SIZE/sizeof(pxa_dma_desc),
	35	.buffer_bytes_max = 128 * 1024,
	36	.fifo_size = 32,
	37	};
	38
	39	int __pxa2xx_pcm_hw_params(struct snd_pcm_substream *substream,
	40	struct snd_pcm_hw_params *params)
	41	{
	42	struct snd_pcm_runtime *runtime = substream->runtime;
	43	struct pxa2xx_runtime_data *rtd = runtime->private_data;
	44	size_t totsize = params_buffer_bytes(params);
	45	size_t period = params_period_bytes(params);
	46	pxa_dma_desc *dma_desc;
	47	dma_addr_t dma_buff_phys, next_desc_phys;
d65a1458 DM	48	u32 dcmd = DCMD_INCSRCADDR \| DCMD_FLOWTRG;
	49
	50	/* temporary transition hack */
	51	switch (rtd->params->addr_width) {
	52	case DMA_SLAVE_BUSWIDTH_1_BYTE:
	53	dcmd \|= DCMD_WIDTH1;
	54	break;
	55	case DMA_SLAVE_BUSWIDTH_2_BYTES:
	56	dcmd \|= DCMD_WIDTH2;
	57	break;
	58	case DMA_SLAVE_BUSWIDTH_4_BYTES:
	59	dcmd \|= DCMD_WIDTH4;
	60	break;
	61	default:
	62	/* can't happen */
	63	break;
	64	}
	65
	66	switch (rtd->params->maxburst) {
	67	case 8:
	68	dcmd \|= DCMD_BURST8;
	69	break;
	70	case 16:
	71	dcmd \|= DCMD_BURST16;
	72	break;
	73	case 32:
	74	dcmd \|= DCMD_BURST32;
	75	break;
	76	}
a6d77317 DB	77
	78	snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer);
	79	runtime->dma_bytes = totsize;
	80
	81	dma_desc = rtd->dma_desc_array;
	82	next_desc_phys = rtd->dma_desc_array_phys;
	83	dma_buff_phys = runtime->dma_addr;
	84	do {
	85	next_desc_phys += sizeof(pxa_dma_desc);
	86	dma_desc->ddadr = next_desc_phys;
	87	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
	88	dma_desc->dsadr = dma_buff_phys;
d65a1458	89	dma_desc->dtadr = rtd->params->addr;
a6d77317	90	} else {
d65a1458	91	dma_desc->dsadr = rtd->params->addr;
a6d77317 DB	92	dma_desc->dtadr = dma_buff_phys;
	93	}
	94	if (period > totsize)
	95	period = totsize;
d65a1458	96	dma_desc->dcmd = dcmd \| period \| DCMD_ENDIRQEN;
a6d77317 DB	97	dma_desc++;
	98	dma_buff_phys += period;
	99	} while (totsize -= period);
	100	dma_desc[-1].ddadr = rtd->dma_desc_array_phys;
	101
	102	return 0;
	103	}
	104	EXPORT_SYMBOL(__pxa2xx_pcm_hw_params);
	105
	106	int __pxa2xx_pcm_hw_free(struct snd_pcm_substream *substream)
	107	{
	108	struct pxa2xx_runtime_data *rtd = substream->runtime->private_data;
	109
d65a1458 DM	110	if (rtd && rtd->params && rtd->params->filter_data) {
	111	unsigned long req = (unsigned long ) rtd->params->filter_data;
	112	DRCMR(req) = 0;
	113	}
a6d77317 DB	114
	115	snd_pcm_set_runtime_buffer(substream, NULL);
	116	return 0;
	117	}
	118	EXPORT_SYMBOL(__pxa2xx_pcm_hw_free);
	119
	120	int pxa2xx_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
	121	{
	122	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
	123	int ret = 0;
	124
	125	switch (cmd) {
	126	case SNDRV_PCM_TRIGGER_START:
	127	DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
	128	DCSR(prtd->dma_ch) = DCSR_RUN;
	129	break;
	130
	131	case SNDRV_PCM_TRIGGER_STOP:
	132	case SNDRV_PCM_TRIGGER_SUSPEND:
	133	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
	134	DCSR(prtd->dma_ch) &= ~DCSR_RUN;
	135	break;
	136
	137	case SNDRV_PCM_TRIGGER_RESUME:
	138	DCSR(prtd->dma_ch) \|= DCSR_RUN;
	139	break;
	140	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
	141	DDADR(prtd->dma_ch) = prtd->dma_desc_array_phys;
	142	DCSR(prtd->dma_ch) \|= DCSR_RUN;
	143	break;
	144
	145	default:
	146	ret = -EINVAL;
	147	}
	148
	149	return ret;
	150	}
	151	EXPORT_SYMBOL(pxa2xx_pcm_trigger);
	152
	153	snd_pcm_uframes_t
	154	pxa2xx_pcm_pointer(struct snd_pcm_substream *substream)
	155	{
	156	struct snd_pcm_runtime *runtime = substream->runtime;
	157	struct pxa2xx_runtime_data *prtd = runtime->private_data;
	158
	159	dma_addr_t ptr = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) ?
	160	DSADR(prtd->dma_ch) : DTADR(prtd->dma_ch);
	161	snd_pcm_uframes_t x = bytes_to_frames(runtime, ptr - runtime->dma_addr);
	162
	163	if (x == runtime->buffer_size)
	164	x = 0;
	165	return x;
	166	}
	167	EXPORT_SYMBOL(pxa2xx_pcm_pointer);
	168
	169	int __pxa2xx_pcm_prepare(struct snd_pcm_substream *substream)
	170	{
	171	struct pxa2xx_runtime_data *prtd = substream->runtime->private_data;
d65a1458	172	unsigned long req;
a6d77317	173
f8bae4ca MB	174	if (!prtd \|\| !prtd->params)
	175	return 0;
	176
97c96c07 VK	177	if (prtd->dma_ch == -1)
	178	return -EINVAL;
	179
a6d77317 DB	180	DCSR(prtd->dma_ch) &= ~DCSR_RUN;
	181	DCSR(prtd->dma_ch) = 0;
	182	DCMD(prtd->dma_ch) = 0;
d65a1458 DM	183	req = (unsigned long ) prtd->params->filter_data;
d65a1458 DM	184	DRCMR(req) = prtd->dma_ch \| DRCMR_MAPVLD;
a6d77317 DB	185
	186	return 0;
	187	}
	188	EXPORT_SYMBOL(__pxa2xx_pcm_prepare);
	189
	190	void pxa2xx_pcm_dma_irq(int dma_ch, void *dev_id)
	191	{
	192	struct snd_pcm_substream *substream = dev_id;
a6d77317 DB	193	int dcsr;
	194
	195	dcsr = DCSR(dma_ch);
	196	DCSR(dma_ch) = dcsr & ~DCSR_STOPIRQEN;
	197
	198	if (dcsr & DCSR_ENDINTR) {
	199	snd_pcm_period_elapsed(substream);
	200	} else {
d65a1458 DM	201	printk(KERN_ERR "DMA error on channel %d (DCSR=%#x)\n",
d65a1458 DM	202	dma_ch, dcsr);
46f6c1aa	203	snd_pcm_stream_lock(substream);
a6d77317	204	snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN);
46f6c1aa	205	snd_pcm_stream_unlock(substream);
a6d77317 DB	206	}
	207	}
	208	EXPORT_SYMBOL(pxa2xx_pcm_dma_irq);
	209
	210	int __pxa2xx_pcm_open(struct snd_pcm_substream *substream)
	211	{
	212	struct snd_pcm_runtime *runtime = substream->runtime;
	213	struct pxa2xx_runtime_data *rtd;
	214	int ret;
	215
	216	runtime->hw = pxa2xx_pcm_hardware;
	217
	218	/*
	219	* For mysterious reasons (and despite what the manual says)
	220	* playback samples are lost if the DMA count is not a multiple
	221	* of the DMA burst size. Let's add a rule to enforce that.
	222	*/
	223	ret = snd_pcm_hw_constraint_step(runtime, 0,
	224	SNDRV_PCM_HW_PARAM_PERIOD_BYTES, 32);
	225	if (ret)
	226	goto out;
	227
	228	ret = snd_pcm_hw_constraint_step(runtime, 0,
	229	SNDRV_PCM_HW_PARAM_BUFFER_BYTES, 32);
	230	if (ret)
	231	goto out;
	232
	233	ret = snd_pcm_hw_constraint_integer(runtime,
	234	SNDRV_PCM_HW_PARAM_PERIODS);
	235	if (ret < 0)
	236	goto out;
	237
	238	ret = -ENOMEM;
13095c37	239	rtd = kzalloc(sizeof(*rtd), GFP_KERNEL);
a6d77317 DB	240	if (!rtd)
	241	goto out;
	242	rtd->dma_desc_array =
	243	dma_alloc_writecombine(substream->pcm->card->dev, PAGE_SIZE,
	244	&rtd->dma_desc_array_phys, GFP_KERNEL);
	245	if (!rtd->dma_desc_array)
	246	goto err1;
	247
8727b909	248	rtd->dma_ch = -1;
a6d77317 DB	249	runtime->private_data = rtd;
	250	return 0;
	251
	252	err1:
	253	kfree(rtd);
	254	out:
	255	return ret;
	256	}
	257	EXPORT_SYMBOL(__pxa2xx_pcm_open);
	258
	259	int __pxa2xx_pcm_close(struct snd_pcm_substream *substream)
	260	{
	261	struct snd_pcm_runtime *runtime = substream->runtime;
	262	struct pxa2xx_runtime_data *rtd = runtime->private_data;
	263
	264	dma_free_writecombine(substream->pcm->card->dev, PAGE_SIZE,
	265	rtd->dma_desc_array, rtd->dma_desc_array_phys);
	266	kfree(rtd);
	267	return 0;
	268	}
	269	EXPORT_SYMBOL(__pxa2xx_pcm_close);
	270
	271	int pxa2xx_pcm_mmap(struct snd_pcm_substream *substream,
	272	struct vm_area_struct *vma)
	273	{
	274	struct snd_pcm_runtime *runtime = substream->runtime;
	275	return dma_mmap_writecombine(substream->pcm->card->dev, vma,
	276	runtime->dma_area,
	277	runtime->dma_addr,
	278	runtime->dma_bytes);
	279	}
	280	EXPORT_SYMBOL(pxa2xx_pcm_mmap);
	281
	282	int pxa2xx_pcm_preallocate_dma_buffer(struct snd_pcm *pcm, int stream)
	283	{
	284	struct snd_pcm_substream *substream = pcm->streams[stream].substream;
	285	struct snd_dma_buffer *buf = &substream->dma_buffer;
	286	size_t size = pxa2xx_pcm_hardware.buffer_bytes_max;
	287	buf->dev.type = SNDRV_DMA_TYPE_DEV;
	288	buf->dev.dev = pcm->card->dev;
	289	buf->private_data = NULL;
	290	buf->area = dma_alloc_writecombine(pcm->card->dev, size,
	291	&buf->addr, GFP_KERNEL);
	292	if (!buf->area)
	293	return -ENOMEM;
	294	buf->bytes = size;
	295	return 0;
	296	}
	297	EXPORT_SYMBOL(pxa2xx_pcm_preallocate_dma_buffer);
	298
	299	void pxa2xx_pcm_free_dma_buffers(struct snd_pcm *pcm)
	300	{
	301	struct snd_pcm_substream *substream;
	302	struct snd_dma_buffer *buf;
	303	int stream;
	304
	305	for (stream = 0; stream < 2; stream++) {
	306	substream = pcm->streams[stream].substream;
	307	if (!substream)
	308	continue;
	309	buf = &substream->dma_buffer;
	310	if (!buf->area)
	311	continue;
	312	dma_free_writecombine(pcm->card->dev, buf->bytes,
313	buf->area, buf->addr);
314	buf->area = NULL;
315	}
316	}
317	EXPORT_SYMBOL(pxa2xx_pcm_free_dma_buffers);
318
319	MODULE_AUTHOR("Nicolas Pitre");
320	MODULE_DESCRIPTION("Intel PXA2xx sound library");
321	MODULE_LICENSE("GPL");