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 }
81
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