1 /*
2 * atmel-pcm.c -- ALSA PCM interface for the Atmel atmel SoC.
3 *
4 * Copyright (C) 2005 SAN People
5 * Copyright (C) 2008 Atmel
6 *
7 * Authors: Sedji Gaouaou <sedji.gaouaou@atmel.com>
8 *
9 * Based on at91-pcm. by:
10 * Frank Mandarino <fmandarino@endrelia.com>
11 * Copyright 2006 Endrelia Technologies Inc.
12 *
13 * Based on pxa2xx-pcm.c by:
14 *
15 * Author: Nicolas Pitre
16 * Created: Nov 30, 2004
17 * Copyright: (C) 2004 MontaVista Software, Inc.
18 *
19 * This program is free software; you can redistribute it and/or modify
20 * it under the terms of the GNU General Public License as published by
21 * the Free Software Foundation; either version 2 of the License, or
22 * (at your option) any later version.
23 *
24 * This program is distributed in the hope that it will be useful,
25 * but WITHOUT ANY WARRANTY; without even the implied warranty of
26 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
27 * GNU General Public License for more details.
28 *
29 * You should have received a copy of the GNU General Public License
30 * along with this program; if not, write to the Free Software
31 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
32 */
33
34 #include <linux/module.h>
35 #include <linux/dma-mapping.h>
36 #include <sound/pcm.h>
37 #include <sound/soc.h>
38 #include "atmel-pcm.h"
39
atmel_pcm_preallocate_dma_buffer(struct snd_pcm * pcm,int stream)40 static int atmel_pcm_preallocate_dma_buffer(struct snd_pcm *pcm,
41 int stream)
42 {
43 struct snd_pcm_substream *substream = pcm->streams[stream].substream;
44 struct snd_dma_buffer *buf = &substream->dma_buffer;
45 size_t size = ATMEL_SSC_DMABUF_SIZE;
46
47 buf->dev.type = SNDRV_DMA_TYPE_DEV;
48 buf->dev.dev = pcm->card->dev;
49 buf->private_data = NULL;
50 buf->area = dma_alloc_coherent(pcm->card->dev, size,
51 &buf->addr, GFP_KERNEL);
52 pr_debug("atmel-pcm: alloc dma buffer: area=%p, addr=%p, size=%zu\n",
53 (void *)buf->area, (void *)(long)buf->addr, size);
54
55 if (!buf->area)
56 return -ENOMEM;
57
58 buf->bytes = size;
59 return 0;
60 }
61
atmel_pcm_mmap(struct snd_pcm_substream * substream,struct vm_area_struct * vma)62 int atmel_pcm_mmap(struct snd_pcm_substream *substream,
63 struct vm_area_struct *vma)
64 {
65 return remap_pfn_range(vma, vma->vm_start,
66 substream->dma_buffer.addr >> PAGE_SHIFT,
67 vma->vm_end - vma->vm_start, vma->vm_page_prot);
68 }
69 EXPORT_SYMBOL_GPL(atmel_pcm_mmap);
70
atmel_pcm_new(struct snd_soc_pcm_runtime * rtd)71 int atmel_pcm_new(struct snd_soc_pcm_runtime *rtd)
72 {
73 struct snd_card *card = rtd->card->snd_card;
74 struct snd_pcm *pcm = rtd->pcm;
75 int ret;
76
77 ret = dma_coerce_mask_and_coherent(card->dev, DMA_BIT_MASK(32));
78 if (ret)
79 return ret;
80
81 if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
82 pr_debug("atmel-pcm: allocating PCM playback DMA buffer\n");
83 ret = atmel_pcm_preallocate_dma_buffer(pcm,
84 SNDRV_PCM_STREAM_PLAYBACK);
85 if (ret)
86 goto out;
87 }
88
89 if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
90 pr_debug("atmel-pcm: allocating PCM capture DMA buffer\n");
91 ret = atmel_pcm_preallocate_dma_buffer(pcm,
92 SNDRV_PCM_STREAM_CAPTURE);
93 if (ret)
94 goto out;
95 }
96 out:
97 return ret;
98 }
99 EXPORT_SYMBOL_GPL(atmel_pcm_new);
100
atmel_pcm_free(struct snd_pcm * pcm)101 void atmel_pcm_free(struct snd_pcm *pcm)
102 {
103 struct snd_pcm_substream *substream;
104 struct snd_dma_buffer *buf;
105 int stream;
106
107 for (stream = 0; stream < 2; stream++) {
108 substream = pcm->streams[stream].substream;
109 if (!substream)
110 continue;
111
112 buf = &substream->dma_buffer;
113 if (!buf->area)
114 continue;
115 dma_free_coherent(pcm->card->dev, buf->bytes,
116 buf->area, buf->addr);
117 buf->area = NULL;
118 }
119 }
120 EXPORT_SYMBOL_GPL(atmel_pcm_free);
121
122