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 * The DAI supports packed transfers, eg 2 16-bit samples in a 32-bit word.
 56 * If this flag is set the dmaengine driver won't put any restriction on
 57 * the supported sample formats and set the DMA transfer size to undefined.
 58 * The DAI driver is responsible to disable any unsupported formats in it's
 59 * configuration and catch corner cases that are not already handled in
 60 * the ALSA core.
 61 */
 62#define SND_DMAENGINE_PCM_DAI_FLAG_PACK BIT(0)
 63
 64/**
 65 * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
 66 * @addr: Address of the DAI data source or destination register.
 67 * @addr_width: Width of the DAI data source or destination register.
 68 * @maxburst: Maximum number of words(note: words, as in units of the
 69 * src_addr_width member, not bytes) that can be send to or received from the
 70 * DAI in one burst.
 71 * @slave_id: Slave requester id for the DMA channel.
 72 * @filter_data: Custom DMA channel filter data, this will usually be used when
 73 * requesting the DMA channel.
 74 * @fifo_size: FIFO size of the DAI controller in bytes
 75 * @flags: PCM_DAI flags, only SND_DMAENGINE_PCM_DAI_FLAG_PACK for now
 76 */
 77struct snd_dmaengine_dai_dma_data {
 78	dma_addr_t addr;
 79	enum dma_slave_buswidth addr_width;
 80	u32 maxburst;
 81	unsigned int slave_id;
 82	void *filter_data;
 83	unsigned int fifo_size;
 84	unsigned int flags;
 85};
 86
 87void snd_dmaengine_pcm_set_config_from_dai_data(
 88	const struct snd_pcm_substream *substream,
 89	const struct snd_dmaengine_dai_dma_data *dma_data,
 90	struct dma_slave_config *config);
 91
 92
 93/*
 94 * Try to request the DMA channel using compat_request_channel or
 95 * compat_filter_fn if it couldn't be requested through devicetree.
 96 */
 97#define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
 98/*
 99 * Don't try to request the DMA channels through devicetree. This flag only
100 * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
101 */
102#define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
103/*
104 * The PCM is half duplex and the DMA channel is shared between capture and
105 * playback.
106 */
107#define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
108
109/**
110 * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
111 * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
112 *   PCM substream. Will be called from the PCM drivers hwparams callback.
113 * @compat_request_channel: Callback to request a DMA channel for platforms
114 *   which do not use devicetree.
115 * @compat_filter_fn: Will be used as the filter function when requesting a
116 *  channel for platforms which do not use devicetree. The filter parameter
117 *  will be the DAI's DMA data.
118 * @dma_dev: If set, request DMA channel on this device rather than the DAI
119 *  device.
120 * @chan_names: If set, these custom DMA channel names will be requested at
121 *  registration time.
122 * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
123 * @prealloc_buffer_size: Size of the preallocated audio buffer.
124 *
125 * Note: If both compat_request_channel and compat_filter_fn are set
126 * compat_request_channel will be used to request the channel and
127 * compat_filter_fn will be ignored. Otherwise the channel will be requested
128 * using dma_request_channel with compat_filter_fn as the filter function.
129 */
130struct snd_dmaengine_pcm_config {
131	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
132			struct snd_pcm_hw_params *params,
133			struct dma_slave_config *slave_config);
134	struct dma_chan *(*compat_request_channel)(
135			struct snd_soc_pcm_runtime *rtd,
136			struct snd_pcm_substream *substream);
137	dma_filter_fn compat_filter_fn;
138	struct device *dma_dev;
139	const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
140
141	const struct snd_pcm_hardware *pcm_hardware;
142	unsigned int prealloc_buffer_size;
143};
144
145int snd_dmaengine_pcm_register(struct device *dev,
146	const struct snd_dmaengine_pcm_config *config,
147	unsigned int flags);
148void snd_dmaengine_pcm_unregister(struct device *dev);
149
150int devm_snd_dmaengine_pcm_register(struct device *dev,
151	const struct snd_dmaengine_pcm_config *config,
152	unsigned int flags);
153
154int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
155	struct snd_pcm_hw_params *params,
156	struct dma_slave_config *slave_config);
157
158#endif