kernel/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         if (!imx_dma_is_general_purpose(chan))
  29                 return false;
  30
  31         chan->private = param;
  32
  33         return true;
  34 }
  35
  36 static 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
  51 static 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
  58 int 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         *config = imx_dmaengine_pcm_config;
  66         if (size)
  67                 config->prealloc_buffer_size = size;
  68
  69         pcm_hardware = devm_kzalloc(&pdev->dev,
  70                         sizeof(struct snd_pcm_hardware), GFP_KERNEL);
  71         *pcm_hardware = imx_pcm_hardware;
  72         if (size)
  73                 pcm_hardware->buffer_bytes_max = size;
  74
  75         config->pcm_hardware = pcm_hardware;
  76
  77         return devm_snd_dmaengine_pcm_register(&pdev->dev,
  78                 config,
  79                 SND_DMAENGINE_PCM_FLAG_COMPAT);
  80 }
  81 EXPORT_SYMBOL_GPL(imx_pcm_dma_init);
  82
  83 MODULE_LICENSE("GPL");