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/*
* Copyright (C) 2012, Analog Devices Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*
* 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.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
#ifndef __SOUND_DMAENGINE_PCM_H__
#define __SOUND_DMAENGINE_PCM_H__
#include <sound/pcm.h>
#include <sound/soc.h>
#include <linux/dmaengine.h>
/**
* snd_pcm_substream_to_dma_direction - Get dma_transfer_direction for a PCM
* substream
* @substream: PCM substream
*/
static inline enum dma_transfer_direction
snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream *substream)
{
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
return DMA_MEM_TO_DEV;
else
return DMA_DEV_TO_MEM;
}
int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
const struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config);
int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
struct dma_chan *chan);
int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
dma_filter_fn filter_fn, void *filter_data);
int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
void *filter_data);
struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
/**
* struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
* @addr: Address of the DAI data source or destination register.
* @addr_width: Width of the DAI data source or destination register.
* @maxburst: Maximum number of words(note: words, as in units of the
* src_addr_width member, not bytes) that can be send to or received from the
* DAI in one burst.
* @slave_id: Slave requester id for the DMA channel.
* @filter_data: Custom DMA channel filter data, this will usually be used when
* requesting the DMA channel.
*/
struct snd_dmaengine_dai_dma_data {
dma_addr_t addr;
enum dma_slave_buswidth addr_width;
u32 maxburst;
unsigned int slave_id;
void *filter_data;
};
void snd_dmaengine_pcm_set_config_from_dai_data(
const struct snd_pcm_substream *substream,
const struct snd_dmaengine_dai_dma_data *dma_data,
struct dma_slave_config *config);
/*
* Try to request the DMA channel using compat_request_channel or
* compat_filter_fn if it couldn't be requested through devicetree.
*/
#define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
/*
* Don't try to request the DMA channels through devicetree. This flag only
* makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
*/
#define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
/*
* The platforms dmaengine driver does not support reporting the amount of
* bytes that are still left to transfer.
*/
#define SND_DMAENGINE_PCM_FLAG_NO_RESIDUE BIT(2)
/*
* The PCM is half duplex and the DMA channel is shared between capture and
* playback.
*/
#define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
/**
* struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
* @prepare_slave_config: Callback used to fill in the DMA slave_config for a
* PCM substream. Will be called from the PCM drivers hwparams callback.
* @compat_request_channel: Callback to request a DMA channel for platforms
* which do not use devicetree.
* @compat_filter_fn: Will be used as the filter function when requesting a
* channel for platforms which do not use devicetree. The filter parameter
* will be the DAI's DMA data.
* @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
* @prealloc_buffer_size: Size of the preallocated audio buffer.
*
* Note: If both compat_request_channel and compat_filter_fn are set
* compat_request_channel will be used to request the channel and
* compat_filter_fn will be ignored. Otherwise the channel will be requested
* using dma_request_channel with compat_filter_fn as the filter function.
*/
struct snd_dmaengine_pcm_config {
int (*prepare_slave_config)(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct dma_slave_config *slave_config);
struct dma_chan *(*compat_request_channel)(
struct snd_soc_pcm_runtime *rtd,
struct snd_pcm_substream *substream);
dma_filter_fn compat_filter_fn;
const struct snd_pcm_hardware *pcm_hardware;
unsigned int prealloc_buffer_size;
};
int snd_dmaengine_pcm_register(struct device *dev,
const struct snd_dmaengine_pcm_config *config,
unsigned int flags);
void snd_dmaengine_pcm_unregister(struct device *dev);
int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params,
struct dma_slave_config *slave_config);
#endif
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