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kernel/linux-rt-4.4.41/sound/soc/fsl/imx-pcm-dma.c 2.22 KB
5113f6f70   김현기   kernel add
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  /*
   * imx-pcm-dma-mx2.c  --  ALSA Soc Audio Layer
   *
   * Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
   *
   * This code is based on code copyrighted by Freescale,
   * Liam Girdwood, Javier Martin and probably others.
   *
   *  This program is free software; you can redistribute  it and/or modify it
   *  under  the terms of  the GNU General  Public License as published by the
   *  Free Software Foundation;  either version 2 of the  License, or (at your
   *  option) any later version.
   */
  #include <linux/platform_device.h>
  #include <linux/dmaengine.h>
  #include <linux/types.h>
  #include <linux/module.h>
  
  #include <sound/core.h>
  #include <sound/pcm.h>
  #include <sound/soc.h>
  #include <sound/dmaengine_pcm.h>
  
  #include "imx-pcm.h"
  
  static bool filter(struct dma_chan *chan, void *param)
  {
  	if (!imx_dma_is_general_purpose(chan))
  		return false;
  
  	chan->private = param;
  
  	return true;
  }
  
  static const struct snd_pcm_hardware imx_pcm_hardware = {
  	.info = SNDRV_PCM_INFO_INTERLEAVED |
  		SNDRV_PCM_INFO_BLOCK_TRANSFER |
  		SNDRV_PCM_INFO_MMAP |
  		SNDRV_PCM_INFO_MMAP_VALID |
  		SNDRV_PCM_INFO_PAUSE |
  		SNDRV_PCM_INFO_RESUME,
  	.buffer_bytes_max = IMX_DEFAULT_DMABUF_SIZE,
  	.period_bytes_min = 128,
  	.period_bytes_max = 65535, /* Limited by SDMA engine */
  	.periods_min = 2,
  	.periods_max = 255,
  	.fifo_size = 0,
  };
  
  static const struct snd_dmaengine_pcm_config imx_dmaengine_pcm_config = {
  	.pcm_hardware = &imx_pcm_hardware,
  	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
  	.compat_filter_fn = filter,
  	.prealloc_buffer_size = IMX_DEFAULT_DMABUF_SIZE,
  };
  
  int imx_pcm_dma_init(struct platform_device *pdev, size_t size)
  {
  	struct snd_dmaengine_pcm_config *config;
  	struct snd_pcm_hardware *pcm_hardware;
  
  	config = devm_kzalloc(&pdev->dev,
  			sizeof(struct snd_dmaengine_pcm_config), GFP_KERNEL);
  	*config = imx_dmaengine_pcm_config;
  	if (size)
  		config->prealloc_buffer_size = size;
  
  	pcm_hardware = devm_kzalloc(&pdev->dev,
  			sizeof(struct snd_pcm_hardware), GFP_KERNEL);
  	*pcm_hardware = imx_pcm_hardware;
  	if (size)
  		pcm_hardware->buffer_bytes_max = size;
  
  	config->pcm_hardware = pcm_hardware;
  
  	return devm_snd_dmaengine_pcm_register(&pdev->dev,
  		config,
  		SND_DMAENGINE_PCM_FLAG_COMPAT);
  }
  EXPORT_SYMBOL_GPL(imx_pcm_dma_init);
  
  MODULE_LICENSE("GPL");