include/sound/dmaengine_pcm.h

   1 /* SPDX-License-Identifier: GPL-2.0+
   2  *
   3  *  Copyright (C) 2012, Analog Devices Inc.
   4  *      Author: Lars-Peter Clausen <lars@metafoo.de>
   5  */
   6
   7 #ifndef __SOUND_DMAENGINE_PCM_H__
   8 #define __SOUND_DMAENGINE_PCM_H__
   9
  10 #include <sound/pcm.h>
  11 #include <sound/soc.h>
  12 #include <linux/dmaengine.h>
  13
  14 /**
  15  * snd_pcm_substream_to_dma_direction - Get dma_transfer_direction for a PCM
  16  *   substream
  17  * @substream: PCM substream
  18  */
  19 static inline enum dma_transfer_direction
  20 snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream *substream)
  21 {
  22         if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
  23                 return DMA_MEM_TO_DEV;
  24         else
  25                 return DMA_DEV_TO_MEM;
  26 }
  27
  28 int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
  29         const struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config);
  30 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
  31 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
  32 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
  33
  34 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
  35         struct dma_chan *chan);
  36 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
  37
  38 int snd_dmaengine_pcm_open_request_chan(struct snd_pcm_substream *substream,
  39         dma_filter_fn filter_fn, void *filter_data);
  40 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
  41
  42 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
  43         void *filter_data);
  44 struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
  45
  46 /*
  47  * The DAI supports packed transfers, eg 2 16-bit samples in a 32-bit word.
  48  * If this flag is set the dmaengine driver won't put any restriction on
  49  * the supported sample formats and set the DMA transfer size to undefined.
  50  * The DAI driver is responsible to disable any unsupported formats in it's
  51  * configuration and catch corner cases that are not already handled in
  52  * the ALSA core.
  53  */
  54 #define SND_DMAENGINE_PCM_DAI_FLAG_PACK BIT(0)
  55
  56 /**
  57  * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
  58  * @addr: Address of the DAI data source or destination register.
  59  * @addr_width: Width of the DAI data source or destination register.
  60  * @maxburst: Maximum number of words(note: words, as in units of the
  61  * src_addr_width member, not bytes) that can be send to or received from the
  62  * DAI in one burst.
  63  * @slave_id: Slave requester id for the DMA channel.
  64  * @filter_data: Custom DMA channel filter data, this will usually be used when
  65  * requesting the DMA channel.
  66  * @chan_name: Custom channel name to use when requesting DMA channel.
  67  * @fifo_size: FIFO size of the DAI controller in bytes
  68  * @flags: PCM_DAI flags, only SND_DMAENGINE_PCM_DAI_FLAG_PACK for now
  69  */
  70 struct snd_dmaengine_dai_dma_data {
  71         dma_addr_t addr;
  72         enum dma_slave_buswidth addr_width;
  73         u32 maxburst;
  74         unsigned int slave_id;
  75         void *filter_data;
  76         const char *chan_name;
  77         unsigned int fifo_size;
  78         unsigned int flags;
  79 };
  80
  81 void snd_dmaengine_pcm_set_config_from_dai_data(
  82         const struct snd_pcm_substream *substream,
  83         const struct snd_dmaengine_dai_dma_data *dma_data,
  84         struct dma_slave_config *config);
  85
  86 int snd_dmaengine_pcm_refine_runtime_hwparams(
  87         struct snd_pcm_substream *substream,
  88         struct snd_dmaengine_dai_dma_data *dma_data,
  89         struct snd_pcm_hardware *hw,
  90         struct dma_chan *chan);
  91
  92 /*
  93  * Try to request the DMA channel using compat_request_channel or
  94  * compat_filter_fn if it couldn't be requested through devicetree.
  95  */
  96 #define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
  97 /*
  98  * Don't try to request the DMA channels through devicetree. This flag only
  99  * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
 100  */
 101 #define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
 102 /*
 103  * The PCM is half duplex and the DMA channel is shared between capture and
 104  * playback.
 105  */
 106 #define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
 107
 108 /**
 109  * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
 110  * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
 111  *   PCM substream. Will be called from the PCM drivers hwparams callback.
 112  * @compat_request_channel: Callback to request a DMA channel for platforms
 113  *   which do not use devicetree.
 114  * @process: Callback used to apply processing on samples transferred from/to
 115  *   user space.
 116  * @compat_filter_fn: Will be used as the filter function when requesting a
 117  *  channel for platforms which do not use devicetree. The filter parameter
 118  *  will be the DAI's DMA data.
 119  * @dma_dev: If set, request DMA channel on this device rather than the DAI
 120  *  device.
 121  * @chan_names: If set, these custom DMA channel names will be requested at
 122  *  registration time.
 123  * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
 124  * @prealloc_buffer_size: Size of the preallocated audio buffer.
 125  *
 126  * Note: If both compat_request_channel and compat_filter_fn are set
 127  * compat_request_channel will be used to request the channel and
 128  * compat_filter_fn will be ignored. Otherwise the channel will be requested
 129  * using dma_request_channel with compat_filter_fn as the filter function.
 130  */
 131 struct snd_dmaengine_pcm_config {
 132         int (*prepare_slave_config)(struct snd_pcm_substream *substream,
 133                         struct snd_pcm_hw_params *params,
 134                         struct dma_slave_config *slave_config);
 135         struct dma_chan *(*compat_request_channel)(
 136                         struct snd_soc_pcm_runtime *rtd,
 137                         struct snd_pcm_substream *substream);
 138         int (*process)(struct snd_pcm_substream *substream,
 139                        int channel, unsigned long hwoff,
 140                        void *buf, unsigned long bytes);
 141         dma_filter_fn compat_filter_fn;
 142         struct device *dma_dev;
 143         const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
 144
 145         const struct snd_pcm_hardware *pcm_hardware;
 146         unsigned int prealloc_buffer_size;
 147 };
 148
 149 int snd_dmaengine_pcm_register(struct device *dev,
 150         const struct snd_dmaengine_pcm_config *config,
 151         unsigned int flags);
 152 void snd_dmaengine_pcm_unregister(struct device *dev);
 153
 154 int devm_snd_dmaengine_pcm_register(struct device *dev,
 155         const struct snd_dmaengine_pcm_config *config,
 156         unsigned int flags);
 157
 158 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
 159         struct snd_pcm_hw_params *params,
 160         struct dma_slave_config *slave_config);
 161
 162 #define SND_DMAENGINE_PCM_DRV_NAME "snd_dmaengine_pcm"
 163
 164 #endif