LXR linux/sound/soc/fsl/imx-pcm-dma.c

   1/*
   2 * imx-pcm-dma-mx2.c  --  ALSA Soc Audio Layer
   3 *
   4 * Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
   5 *
   6 * This code is based on code copyrighted by Freescale,
   7 * Liam Girdwood, Javier Martin and probably others.
   8 *
   9 *  This program is free software; you can redistribute  it and/or modify it
  10 *  under  the terms of  the GNU General  Public License as published by the
  11 *  Free Software Foundation;  either version 2 of the  License, or (at your
  12 *  option) any later version.
  13 */
  14#include <linux/platform_device.h>
  15#include <linux/dmaengine.h>
  16#include <linux/types.h>
  17#include <linux/module.h>
  18
  19#include <sound/core.h>
  20#include <sound/pcm.h>
  21#include <sound/soc.h>
  22#include <sound/dmaengine_pcm.h>
  23
  24#include "imx-pcm.h"
  25
  26static bool filter(struct dma_chan *chan, void *param)
  27{
  28        if (!imx_dma_is_general_purpose(chan))
  29                return false;
  30
  31        chan->private = param;
  32
  33        return true;
  34}
  35
  36static const struct snd_pcm_hardware imx_pcm_hardware = {
  37        .info = SNDRV_PCM_INFO_INTERLEAVED |
  38                SNDRV_PCM_INFO_BLOCK_TRANSFER |
  39                SNDRV_PCM_INFO_MMAP |
  40                SNDRV_PCM_INFO_MMAP_VALID |
  41                SNDRV_PCM_INFO_PAUSE |
  42                SNDRV_PCM_INFO_RESUME,
  43        .buffer_bytes_max = IMX_DEFAULT_DMABUF_SIZE,
  44        .period_bytes_min = 128,
  45        .period_bytes_max = 65535, /* Limited by SDMA engine */
  46        .periods_min = 2,
  47        .periods_max = 255,
  48        .fifo_size = 0,
  49};
  50
  51static const struct snd_dmaengine_pcm_config imx_dmaengine_pcm_config = {
  52        .pcm_hardware = &imx_pcm_hardware,
  53        .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
  54        .compat_filter_fn = filter,
  55        .prealloc_buffer_size = IMX_DEFAULT_DMABUF_SIZE,
  56};
  57
  58int imx_pcm_dma_init(struct platform_device *pdev, size_t size)
  59{
  60        struct snd_dmaengine_pcm_config *config;
  61        struct snd_pcm_hardware *pcm_hardware;
  62
  63        config = devm_kzalloc(&pdev->dev,
  64                        sizeof(struct snd_dmaengine_pcm_config), GFP_KERNEL);
  65        if (!config)
  66                return -ENOMEM;
  67        *config = imx_dmaengine_pcm_config;
  68        if (size)
  69                config->prealloc_buffer_size = size;
  70
  71        pcm_hardware = devm_kzalloc(&pdev->dev,
  72                        sizeof(struct snd_pcm_hardware), GFP_KERNEL);
  73        *pcm_hardware = imx_pcm_hardware;
  74        if (size)
  75                pcm_hardware->buffer_bytes_max = size;
  76
  77        config->pcm_hardware = pcm_hardware;
  78
  79        return devm_snd_dmaengine_pcm_register(&pdev->dev,
  80                config,
  81                SND_DMAENGINE_PCM_FLAG_COMPAT);
  82}
  83EXPORT_SYMBOL_GPL(imx_pcm_dma_init);
  84
  85MODULE_LICENSE("GPL");
  86