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 * Return: DMA transfer direction
 20 */
 21static inline enum dma_transfer_direction
 22snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream *substream)
 23{
 24	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
 25		return DMA_MEM_TO_DEV;
 26	else
 27		return DMA_DEV_TO_MEM;
 28}
 29
 30int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
 31	const struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config);
 32int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
 33snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
 34snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
 35
 36int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
 37	struct dma_chan *chan);
 38int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
 39int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream);
 40
 41int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
 42
 43struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
 44	void *filter_data);
 45struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream);
 46
 47/*
 48 * The DAI supports packed transfers, eg 2 16-bit samples in a 32-bit word.
 49 * If this flag is set the dmaengine driver won't put any restriction on
 50 * the supported sample formats and set the DMA transfer size to undefined.
 51 * The DAI driver is responsible to disable any unsupported formats in it's
 52 * configuration and catch corner cases that are not already handled in
 53 * the ALSA core.
 54 */
 55#define SND_DMAENGINE_PCM_DAI_FLAG_PACK BIT(0)
 56
 57/**
 58 * struct snd_dmaengine_dai_dma_data - DAI DMA configuration data
 59 * @addr: Address of the DAI data source or destination register.
 60 * @addr_width: Width of the DAI data source or destination register.
 61 * @maxburst: Maximum number of words(note: words, as in units of the
 62 * src_addr_width member, not bytes) that can be send to or received from the
 63 * DAI in one burst.
 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 * @peripheral_config: peripheral configuration for programming peripheral
 70 * for dmaengine transfer
 71 * @peripheral_size: peripheral configuration buffer size
 72 * @port_window_size: The length of the register area in words the data need
 73 * to be accessed on the device side. It is only used for devices which is using
 74 * an area instead of a single register to send/receive the data. Typically the
 75 * DMA loops in this area in order to transfer the data.
 76 */
 77struct snd_dmaengine_dai_dma_data {
 78	dma_addr_t addr;
 79	enum dma_slave_buswidth addr_width;
 80	u32 maxburst;
 81	void *filter_data;
 82	const char *chan_name;
 83	unsigned int fifo_size;
 84	unsigned int flags;
 85	void *peripheral_config;
 86	size_t peripheral_size;
 87	u32 port_window_size;
 88};
 89
 90void snd_dmaengine_pcm_set_config_from_dai_data(
 91	const struct snd_pcm_substream *substream,
 92	const struct snd_dmaengine_dai_dma_data *dma_data,
 93	struct dma_slave_config *config);
 94
 95int snd_dmaengine_pcm_refine_runtime_hwparams(
 96	struct snd_pcm_substream *substream,
 97	struct snd_dmaengine_dai_dma_data *dma_data,
 98	struct snd_pcm_hardware *hw,
 99	struct dma_chan *chan);
100
101/*
102 * Try to request the DMA channel using compat_request_channel or
103 * compat_filter_fn if it couldn't be requested through devicetree.
104 */
105#define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
106/*
107 * Don't try to request the DMA channels through devicetree. This flag only
108 * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
109 */
110#define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
111/*
112 * The PCM is half duplex and the DMA channel is shared between capture and
113 * playback.
114 */
115#define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
116
117/**
118 * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
119 * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
120 *   PCM substream. Will be called from the PCM drivers hwparams callback.
121 * @compat_request_channel: Callback to request a DMA channel for platforms
122 *   which do not use devicetree.
123 * @process: Callback used to apply processing on samples transferred from/to
124 *   user space.
125 * @name: Component name. If null, dev_name will be used.
126 * @compat_filter_fn: Will be used as the filter function when requesting a
127 *  channel for platforms which do not use devicetree. The filter parameter
128 *  will be the DAI's DMA data.
129 * @dma_dev: If set, request DMA channel on this device rather than the DAI
130 *  device.
131 * @chan_names: If set, these custom DMA channel names will be requested at
132 *  registration time.
133 * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
134 * @prealloc_buffer_size: Size of the preallocated audio buffer.
135 *
136 * Note: If both compat_request_channel and compat_filter_fn are set
137 * compat_request_channel will be used to request the channel and
138 * compat_filter_fn will be ignored. Otherwise the channel will be requested
139 * using dma_request_channel with compat_filter_fn as the filter function.
140 */
141struct snd_dmaengine_pcm_config {
142	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
143			struct snd_pcm_hw_params *params,
144			struct dma_slave_config *slave_config);
145	struct dma_chan *(*compat_request_channel)(
146			struct snd_soc_pcm_runtime *rtd,
147			struct snd_pcm_substream *substream);
148	int (*process)(struct snd_pcm_substream *substream,
149		       int channel, unsigned long hwoff,
150		       unsigned long bytes);
151	const char *name;
152	dma_filter_fn compat_filter_fn;
153	struct device *dma_dev;
154	const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
155
156	const struct snd_pcm_hardware *pcm_hardware;
157	unsigned int prealloc_buffer_size;
158};
159
160int snd_dmaengine_pcm_register(struct device *dev,
161	const struct snd_dmaengine_pcm_config *config,
162	unsigned int flags);
163void snd_dmaengine_pcm_unregister(struct device *dev);
164
165int devm_snd_dmaengine_pcm_register(struct device *dev,
166	const struct snd_dmaengine_pcm_config *config,
167	unsigned int flags);
168
169int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
170	struct snd_pcm_hw_params *params,
171	struct dma_slave_config *slave_config);
172
173#define SND_DMAENGINE_PCM_DRV_NAME "snd_dmaengine_pcm"
174
175struct dmaengine_pcm {
176	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
177	const struct snd_dmaengine_pcm_config *config;
178	struct snd_soc_component component;
179	unsigned int flags;
180};
181
182static inline struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p)
183{
184	return container_of(p, struct dmaengine_pcm, component);
185}
186#endif