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  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 *)(long)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
 71int 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}
 99EXPORT_SYMBOL_GPL(atmel_pcm_new);
100
101void 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}
120EXPORT_SYMBOL_GPL(atmel_pcm_free);
121