LXR linux/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
  40static 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 *)buf->addr, size);
  54
  55        if (!buf->area)
  56                return -ENOMEM;
  57
  58        buf->bytes = size;
  59        return 0;
  60}
  61
  62int 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}
  69EXPORT_SYMBOL_GPL(atmel_pcm_mmap);
  70
  71static u64 atmel_pcm_dmamask = DMA_BIT_MASK(32);
  72
  73int atmel_pcm_new(struct snd_soc_pcm_runtime *rtd)
  74{
  75        struct snd_card *card = rtd->card->snd_card;
  76        struct snd_pcm *pcm = rtd->pcm;
  77        int ret = 0;
  78
  79        if (!card->dev->dma_mask)
  80                card->dev->dma_mask = &atmel_pcm_dmamask;
  81        if (!card->dev->coherent_dma_mask)
  82                card->dev->coherent_dma_mask = DMA_BIT_MASK(32);
  83
  84        if (pcm->streams[SNDRV_PCM_STREAM_PLAYBACK].substream) {
  85                pr_debug("atmel-pcm: allocating PCM playback DMA buffer\n");
  86                ret = atmel_pcm_preallocate_dma_buffer(pcm,
  87                        SNDRV_PCM_STREAM_PLAYBACK);
  88                if (ret)
  89                        goto out;
  90        }
  91
  92        if (pcm->streams[SNDRV_PCM_STREAM_CAPTURE].substream) {
  93                pr_debug("atmel-pcm: allocating PCM capture DMA buffer\n");
  94                ret = atmel_pcm_preallocate_dma_buffer(pcm,
  95                        SNDRV_PCM_STREAM_CAPTURE);
  96                if (ret)
  97                        goto out;
  98        }
  99 out:
 100        return ret;
 101}
 102EXPORT_SYMBOL_GPL(atmel_pcm_new);
 103
 104void atmel_pcm_free(struct snd_pcm *pcm)
 105{
 106        struct snd_pcm_substream *substream;
 107        struct snd_dma_buffer *buf;
 108        int stream;
 109
 110        for (stream = 0; stream < 2; stream++) {
 111                substream = pcm->streams[stream].substream;
 112                if (!substream)
 113                        continue;
 114
 115                buf = &substream->dma_buffer;
 116                if (!buf->area)
 117                        continue;
 118                dma_free_coherent(pcm->card->dev, buf->bytes,
 119                                  buf->area, buf->addr);
 120                buf->area = NULL;
 121        }
 122}
 123EXPORT_SYMBOL_GPL(atmel_pcm_free);
 124
 125