xref: /linux/include/sound/dmaengine_pcm.h (revision 05a54fa773284d1a7923cdfdd8f0c8dabb98bd26)
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  */
21 static inline enum dma_transfer_direction
22 snd_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 
30 int 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);
32 int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd);
33 snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream);
34 snd_pcm_uframes_t snd_dmaengine_pcm_pointer_no_residue(struct snd_pcm_substream *substream);
35 
36 int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
37 	struct dma_chan *chan);
38 int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream);
39 int snd_dmaengine_pcm_sync_stop(struct snd_pcm_substream *substream);
40 
41 int snd_dmaengine_pcm_close_release_chan(struct snd_pcm_substream *substream);
42 
43 struct dma_chan *snd_dmaengine_pcm_request_channel(dma_filter_fn filter_fn,
44 	void *filter_data);
45 struct 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  */
77 struct 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 
90 void 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 
95 int 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  */
141 struct 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 
160 int snd_dmaengine_pcm_register(struct device *dev,
161 	const struct snd_dmaengine_pcm_config *config,
162 	unsigned int flags);
163 void snd_dmaengine_pcm_unregister(struct device *dev);
164 
165 int devm_snd_dmaengine_pcm_register(struct device *dev,
166 	const struct snd_dmaengine_pcm_config *config,
167 	unsigned int flags);
168 
169 int 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 
175 struct 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 
182 static 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
187