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
  26 static bool filter(struct dma_chan *chan, void *param)
  27 {
  28         struct snd_dmaengine_dai_dma_data *dma_data = param;
  29
  30         if (!imx_dma_is_general_purpose(chan))
  31                 return false;
  32
  33         chan->private = dma_data->filter_data;
  34
  35         return true;
  36 }
  37
  38 static const struct snd_pcm_hardware imx_pcm_hardware = {
  39         .info = SNDRV_PCM_INFO_INTERLEAVED |
  40                 SNDRV_PCM_INFO_BLOCK_TRANSFER |
  41                 SNDRV_PCM_INFO_MMAP |
  42                 SNDRV_PCM_INFO_MMAP_VALID |
  43                 SNDRV_PCM_INFO_PAUSE |
  44                 SNDRV_PCM_INFO_RESUME,
  45         .formats = SNDRV_PCM_FMTBIT_S16_LE,
  46         .rate_min = 8000,
  47         .channels_min = 2,
  48         .channels_max = 2,
  49         .buffer_bytes_max = IMX_SSI_DMABUF_SIZE,
  50         .period_bytes_min = 128,
  51         .period_bytes_max = 65535, /* Limited by SDMA engine */
  52         .periods_min = 2,
  53         .periods_max = 255,
  54         .fifo_size = 0,
  55 };
  56
  57 static const struct snd_dmaengine_pcm_config imx_dmaengine_pcm_config = {
  58         .pcm_hardware = &imx_pcm_hardware,
  59         .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
  60         .compat_filter_fn = filter,
  61         .prealloc_buffer_size = IMX_SSI_DMABUF_SIZE,
  62 };
  63
  64 int imx_pcm_dma_init(struct platform_device *pdev)
  65 {
  66         return snd_dmaengine_pcm_register(&pdev->dev, &imx_dmaengine_pcm_config,
  67                 SND_DMAENGINE_PCM_FLAG_NO_RESIDUE |
  68                 SND_DMAENGINE_PCM_FLAG_COMPAT);
  69 }
  70 EXPORT_SYMBOL_GPL(imx_pcm_dma_init);
  71
  72 void imx_pcm_dma_exit(struct platform_device *pdev)
  73 {
  74         snd_dmaengine_pcm_unregister(&pdev->dev);
  75 }
  76 EXPORT_SYMBOL_GPL(imx_pcm_dma_exit);
  77
  78 MODULE_LICENSE("GPL");