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authorRussell King <rmk@arm.linux.org.uk>2005-05-12 04:25:58 -0400
committerJaroslav Kysela <perex@suse.cz>2005-05-29 04:06:49 -0400
commit9b9a5afffd8636a82c6b32970342aef9d1f3d17d (patch)
tree459b442ae9d43f988c3dcd1b6cf154fd76b1861b /sound/arm
parentf7de9cfd25b6867a2854d98d734e03e1a9fc65fb (diff)
[ALSA] ARM DMA subsystem
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>
Diffstat (limited to 'sound/arm')
-rw-r--r--sound/arm/devdma.c81
-rw-r--r--sound/arm/devdma.h3
2 files changed, 84 insertions, 0 deletions
diff --git a/sound/arm/devdma.c b/sound/arm/devdma.c
new file mode 100644
index 000000000000..60826a5324b4
--- /dev/null
+++ b/sound/arm/devdma.c
@@ -0,0 +1,81 @@
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
21void devdma_hw_free(struct device *dev, snd_pcm_substream_t *substream)
22{
23 snd_pcm_runtime_t *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
37int devdma_hw_alloc(struct device *dev, snd_pcm_substream_t *substream, size_t size)
38{
39 snd_pcm_runtime_t *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
77int devdma_mmap(struct device *dev, snd_pcm_substream_t *substream, struct vm_area_struct *vma)
78{
79 snd_pcm_runtime_t *runtime = substream->runtime;
80 return dma_mmap_coherent(dev, vma, runtime->dma_area, runtime->dma_addr, runtime->dma_bytes);
81}
diff --git a/sound/arm/devdma.h b/sound/arm/devdma.h
new file mode 100644
index 000000000000..5a33b6bacc34
--- /dev/null
+++ b/sound/arm/devdma.h
@@ -0,0 +1,3 @@
1void devdma_hw_free(struct device *dev, snd_pcm_substream_t *substream);
2int devdma_hw_alloc(struct device *dev, snd_pcm_substream_t *substream, size_t size);
3int devdma_mmap(struct device *dev, snd_pcm_substream_t *substream, struct vm_area_struct *vma);