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9b9a5afffd
ARM DMA routines The patch below adds a convenient re-usable shim around the extended ARM DMA API, and is used by several ARM ALSA drivers. Signed-off-by: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Takashi Iwai <tiwai@suse.de>
82 lines
2.0 KiB
C
82 lines
2.0 KiB
C
/*
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* linux/sound/arm/devdma.c
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*
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* Copyright (C) 2003-2004 Russell King, All rights reserved.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* ARM DMA shim for ALSA.
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*/
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#include <linux/device.h>
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#include <linux/dma-mapping.h>
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#include <sound/driver.h>
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#include <sound/core.h>
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#include <sound/pcm.h>
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#include "devdma.h"
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void devdma_hw_free(struct device *dev, snd_pcm_substream_t *substream)
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{
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snd_pcm_runtime_t *runtime = substream->runtime;
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struct snd_dma_buffer *buf = runtime->dma_buffer_p;
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if (runtime->dma_area == NULL)
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return;
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if (buf != &substream->dma_buffer) {
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dma_free_coherent(buf->dev.dev, buf->bytes, buf->area, buf->addr);
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kfree(runtime->dma_buffer_p);
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}
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snd_pcm_set_runtime_buffer(substream, NULL);
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}
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int devdma_hw_alloc(struct device *dev, snd_pcm_substream_t *substream, size_t size)
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{
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snd_pcm_runtime_t *runtime = substream->runtime;
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struct snd_dma_buffer *buf = runtime->dma_buffer_p;
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int ret = 0;
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if (buf) {
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if (buf->bytes >= size)
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goto out;
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devdma_hw_free(dev, substream);
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}
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if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) {
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buf = &substream->dma_buffer;
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} else {
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buf = kmalloc(sizeof(struct snd_dma_buffer), GFP_KERNEL);
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if (!buf)
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goto nomem;
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buf->dev.type = SNDRV_DMA_TYPE_DEV;
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buf->dev.dev = dev;
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buf->area = dma_alloc_coherent(dev, size, &buf->addr, GFP_KERNEL);
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buf->bytes = size;
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buf->private_data = NULL;
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if (!buf->area)
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goto free;
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}
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snd_pcm_set_runtime_buffer(substream, buf);
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ret = 1;
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out:
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runtime->dma_bytes = size;
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return ret;
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free:
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kfree(buf);
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nomem:
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return -ENOMEM;
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}
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int devdma_mmap(struct device *dev, snd_pcm_substream_t *substream, struct vm_area_struct *vma)
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{
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snd_pcm_runtime_t *runtime = substream->runtime;
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return dma_mmap_coherent(dev, vma, runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);
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}
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