sound/arm/devdma.c

   1 /*
   2  *  linux/sound/arm/devdma.c
   3  *
   4  *  Copyright (C) 2003-2004 Russell King, All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  *
  10  *  ARM DMA shim for ALSA.
  11  */
  12 #include <linux/device.h>
  13 #include <linux/dma-mapping.h>
  14
  15 #include <sound/core.h>
  16 #include <sound/pcm.h>
  17
  18 #include "devdma.h"
  19
  20 void devdma_hw_free(struct device *dev, struct snd_pcm_substream *substream)
  21 {
  22         struct snd_pcm_runtime *runtime = substream->runtime;
  23         struct snd_dma_buffer *buf = runtime->dma_buffer_p;
  24
  25         if (runtime->dma_area == NULL)
  26                 return;
  27
  28         if (buf != &substream->dma_buffer) {
  29                 dma_free_coherent(buf->dev.dev, buf->bytes, buf->area, buf->addr);
  30                 kfree(runtime->dma_buffer_p);
  31         }
  32
  33         snd_pcm_set_runtime_buffer(substream, NULL);
  34 }
  35
  36 int devdma_hw_alloc(struct device *dev, struct snd_pcm_substream *substream, size_t size)
  37 {
  38         struct snd_pcm_runtime *runtime = substream->runtime;
  39         struct snd_dma_buffer *buf = runtime->dma_buffer_p;
  40         int ret = 0;
  41
  42         if (buf) {
  43                 if (buf->bytes >= size)
  44                         goto out;
  45                 devdma_hw_free(dev, substream);
  46         }
  47
  48         if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) {
  49                 buf = &substream->dma_buffer;
  50         } else {
  51                 buf = kmalloc(sizeof(struct snd_dma_buffer), GFP_KERNEL);
  52                 if (!buf)
  53                         goto nomem;
  54
  55                 buf->dev.type = SNDRV_DMA_TYPE_DEV;
  56                 buf->dev.dev = dev;
  57                 buf->area = dma_alloc_coherent(dev, size, &buf->addr, GFP_KERNEL);
  58                 buf->bytes = size;
  59                 buf->private_data = NULL;
  60
  61                 if (!buf->area)
  62                         goto free;
  63         }
  64         snd_pcm_set_runtime_buffer(substream, buf);
  65         ret = 1;
  66  out:
  67         runtime->dma_bytes = size;
  68         return ret;
  69
  70  free:
  71         kfree(buf);
  72  nomem:
  73         return -ENOMEM;
  74 }
  75
  76 int devdma_mmap(struct device *dev, struct snd_pcm_substream *substream, struct vm_area_struct *vma)
  77 {
  78         struct snd_pcm_runtime *runtime = substream->runtime;
  79         return dma_mmap_coherent(dev, vma, runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);
  80 }