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 140