[ALSA] ARM DMA subsystem

/*

 *  linux/sound/arm/devdma.c

 *

 *  Copyright (C) 2003-2004 Russell King, All rights reserved.

 *

 * 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.

 *

 *  ARM DMA shim for ALSA.

 */

#include <linux/device.h>

#include <linux/dma-mapping.h>

#include <sound/driver.h>

#include <sound/core.h>

#include <sound/pcm.h>

#include "devdma.h"

void devdma_hw_free(struct device *dev, snd_pcm_substream_t *substream)

{

	snd_pcm_runtime_t *runtime = substream->runtime;

	struct snd_dma_buffer *buf = runtime->dma_buffer_p;

	if (runtime->dma_area == NULL)

		return;

	if (buf != &substream->dma_buffer) {

		dma_free_coherent(buf->dev.dev, buf->bytes, buf->area, buf->addr);

		kfree(runtime->dma_buffer_p);

	}

	snd_pcm_set_runtime_buffer(substream, NULL);

}

int devdma_hw_alloc(struct device *dev, snd_pcm_substream_t *substream, size_t size)

{

	snd_pcm_runtime_t *runtime = substream->runtime;

	struct snd_dma_buffer *buf = runtime->dma_buffer_p;

	int ret = 0;

	if (buf) {

		if (buf->bytes >= size)

			goto out;

		devdma_hw_free(dev, substream);

	}

	if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) {

		buf = &substream->dma_buffer;

	} else {

		buf = kmalloc(sizeof(struct snd_dma_buffer), GFP_KERNEL);

		if (!buf)

			goto nomem;

		buf->dev.type = SNDRV_DMA_TYPE_DEV;

		buf->dev.dev = dev;

		buf->area = dma_alloc_coherent(dev, size, &buf->addr, GFP_KERNEL);

		buf->bytes = size;

		buf->private_data = NULL;

		if (!buf->area)

			goto free;

	}

	snd_pcm_set_runtime_buffer(substream, buf);

	ret = 1;

 out:

	runtime->dma_bytes = size;

	return ret;

 free:

	kfree(buf);

 nomem:

	return -ENOMEM;

}

int devdma_mmap(struct device *dev, snd_pcm_substream_t *substream, struct vm_area_struct *vma)

{

	snd_pcm_runtime_t *runtime = substream->runtime;

	return dma_mmap_coherent(dev, vma, runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);

}

void devdma_hw_free(struct device *dev, snd_pcm_substream_t *substream);

int devdma_hw_alloc(struct device *dev, snd_pcm_substream_t *substream, size_t size);

int devdma_mmap(struct device *dev, snd_pcm_substream_t *substream, struct vm_area_struct *vma);