linux/include/sound/dmaengine_pcm.h
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   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 */
  27static inline enum dma_transfer_direction
  28snd_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
  36int 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);
  38int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
  39snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
  40snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
  41
  42int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
  43        struct dma_chan *chan);
  44int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
  45
  46int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
  47        dma_filter_fn filter_fn, void *filter_data);
  48int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
  49
  50struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
  51        void *filter_data);
  52struct 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 */
  65struct 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
  73void 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 */
 117struct 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
 130int snd_dmaengine_pcm_register(struct device *dev,
 131        const struct snd_dmaengine_pcm_config *config,
 132        unsigned int flags);
 133void snd_dmaengine_pcm_unregister(struct device *dev);
 134
 135int 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
 140
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