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/driver.h>
  16 #include <sound/core.h>
  17 #include <sound/pcm.h>
  18
  19 #include "devdma.h"
  20
  21 void devdma_hw_free(struct device *dev, struct snd_pcm_substream *substream)
  22 {
  23         struct snd_pcm_runtime *runtime = substream->runtime;
  24         struct snd_dma_buffer *buf = runtime->dma_buffer_p;
  25
  26         if (runtime->dma_area == NULL)
  27                 return;
  28
  29         if (buf != &substream->dma_buffer) {
  30                 dma_free_coherent(buf->dev.dev, buf->bytes, buf->area, buf->addr);
  31                 kfree(runtime->dma_buffer_p);
  32         }
  33
  34         snd_pcm_set_runtime_buffer(substream, NULL);
  35 }
  36
  37 int devdma_hw_alloc(struct device *dev, struct snd_pcm_substream *substream, size_t size)
  38 {
  39         struct snd_pcm_runtime *runtime = substream->runtime;
  40         struct snd_dma_buffer *buf = runtime->dma_buffer_p;
  41         int ret = 0;
  42
  43         if (buf) {
  44                 if (buf->bytes >= size)
  45                         goto out;
  46                 devdma_hw_free(dev, substream);
  47         }
  48
  49         if (substream->dma_buffer.area != NULL && substream->dma_buffer.bytes >= size) {
  50                 buf = &substream->dma_buffer;
  51         } else {
  52                 buf = kmalloc(sizeof(struct snd_dma_buffer), GFP_KERNEL);
  53                 if (!buf)
  54                         goto nomem;
  55
  56                 buf->dev.type = SNDRV_DMA_TYPE_DEV;
  57                 buf->dev.dev = dev;
  58                 buf->area = dma_alloc_coherent(dev, size, &buf->addr, GFP_KERNEL);
  59                 buf->bytes = size;
  60                 buf->private_data = NULL;
  61
  62                 if (!buf->area)
  63                         goto free;
  64         }
  65         snd_pcm_set_runtime_buffer(substream, buf);
  66         ret = 1;
  67  out:
  68         runtime->dma_bytes = size;
  69         return ret;
  70
  71  free:
  72         kfree(buf);
  73  nomem:
  74         return -ENOMEM;
  75 }
  76
  77 int devdma_mmap(struct device *dev, struct snd_pcm_substream *substream, struct vm_area_struct *vma)
  78 {
  79         struct snd_pcm_runtime *runtime = substream->runtime;
  80         return dma_mmap_coherent(dev, vma, runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);
  81 }