sound/soc/atmel/atmel-pcm.c

   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
  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
  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
  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
 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