include/sound/dmaengine_pcm.h

   1 /*
   2  *  Copyright (C) 2012, Analog Devices Inc.
   3  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   4  *
   5  *  This program is free software; you can redistribute it and/or modify it
   6  *  under  the terms of the GNU General  Public License as published by the
   7  *  Free Software Foundation;  either version 2 of the License, or (at your
   8  *  option) any later version.
   9  *
  10  *  You should have received a copy of the GNU General Public License along
  11  *  with this program; if not, write to the Free Software Foundation, Inc.,
  12  *  675 Mass Ave, Cambridge, MA 02139, USA.
  13  *
  14  */
  15 #ifndef __SOUND_DMAENGINE_PCM_H__
  16 #define __SOUND_DMAENGINE_PCM_H__
  17
  18 #include <sound/pcm.h>
  19 #include <sound/soc.h>
  20 #include <linux/dmaengine.h>
  21
  22 /**
  23  * snd_pcm_substream_to_dma_direction - Get dma_transfer_direction for a PCM
  24  *   substream
  25  * @substream: PCM substream
  26  */
  27 static inline enum dma_transfer_direction
  28 snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream *substream)
  29 {
  30         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  31                 return DMA_MEM_TO_DEV;
  32         else
  33                 return DMA_DEV_TO_MEM;
  34 }
  35
  36 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  37         const struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config);
  38 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
  39 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
  40 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
  41
  42 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
  43         struct dma_chan *chan);
  44 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
  45
  46 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
  47         dma_filter_fn filter_fn, void *filter_data);
  48 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
  49
  50 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
  51         void *filter_data);
  52 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
  53
  54 /**
  55  * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
  56  * @addr: Address of the DAI data source or destination register.
  57  * @addr_width: Width of the DAI data source or destination register.
  58  * @maxburst: Maximum number of words(note: words, as in units of the
  59  * src_addr_width member, not bytes) that can be send to or received from the
  60  * DAI in one burst.
  61  * @slave_id: Slave requester id for the DMA channel.
  62  * @filter_data: Custom DMA channel filter data, this will usually be used when
  63  * requesting the DMA channel.
  64  */
  65 struct snd_dmaengine_dai_dma_data {
  66         dma_addr_t addr;
  67         enum dma_slave_buswidth addr_width;
  68         u32 maxburst;
  69         unsigned int slave_id;
  70         void *filter_data;
  71 };
  72
  73 void snd_dmaengine_pcm_set_config_from_dai_data(
  74         const struct snd_pcm_substream *substream,
  75         const struct snd_dmaengine_dai_dma_data *dma_data,
  76         struct dma_slave_config *config);
  77
  78
  79 /*
  80  * Try to request the DMA channel using compat_request_channel or
  81  * compat_filter_fn if it couldn't be requested through devicetree.
  82  */
  83 #define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
  84 /*
  85  * Don't try to request the DMA channels through devicetree. This flag only
  86  * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
  87  */
  88 #define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
  89 /*
  90  * The platforms dmaengine driver does not support reporting the amount of
  91  * bytes that are still left to transfer.
  92  */
  93 #define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(2)
  94 /*
  95  * The PCM is half duplex and the DMA channel is shared between capture and
  96  * playback.
  97  */
  98 #define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
  99
 100 /**
 101  * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
 102  * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
 103  *   PCM substream. Will be called from the PCM drivers hwparams callback.
 104  * @compat_request_channel: Callback to request a DMA channel for platforms
 105  *   which do not use devicetree.
 106  * @compat_filter_fn: Will be used as the filter function when requesting a
 107  *  channel for platforms which do not use devicetree. The filter parameter
 108  *  will be the DAI's DMA data.
 109  * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
 110  * @prealloc_buffer_size: Size of the preallocated audio buffer.
 111  *
 112  * Note: If both compat_request_channel and compat_filter_fn are set
 113  * compat_request_channel will be used to request the channel and
 114  * compat_filter_fn will be ignored. Otherwise the channel will be requested
 115  * using dma_request_channel with compat_filter_fn as the filter function.
 116  */
 117 struct snd_dmaengine_pcm_config {
 118         int (*prepare_slave_config)(struct snd_pcm_substream *substream,
 119                         struct snd_pcm_hw_params *params,
 120                         struct dma_slave_config *slave_config);
 121         struct dma_chan *(*compat_request_channel)(
 122                         struct snd_soc_pcm_runtime *rtd,
 123                         struct snd_pcm_substream *substream);
 124         dma_filter_fn compat_filter_fn;
 125
 126         const struct snd_pcm_hardware *pcm_hardware;
 127         unsigned int prealloc_buffer_size;
 128 };
 129
 130 int snd_dmaengine_pcm_register(struct device *dev,
 131         const struct snd_dmaengine_pcm_config *config,
 132         unsigned int flags);
 133 void snd_dmaengine_pcm_unregister(struct device *dev);
 134
 135 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
 136         struct snd_pcm_hw_params *params,
 137         struct dma_slave_config *slave_config);
 138
 139 #endif