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
snd_pcm_substream_to_dma_direction(const struct snd_pcm_substream * substream)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
87 /*
88 * Try to request the DMA channel using compat_request_channel or
89 * compat_filter_fn if it couldn't be requested through devicetree.
90 */
91 #define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
92 /*
93 * Don't try to request the DMA channels through devicetree. This flag only
94 * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
95 */
96 #define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
97 /*
98 * The PCM is half duplex and the DMA channel is shared between capture and
99 * playback.
100 */
101 #define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
102 /*
103 * The PCM streams have custom channel names specified.
104 */
105 #define SND_DMAENGINE_PCM_FLAG_CUSTOM_CHANNEL_NAME BIT(4)
106
107 /**
108 * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
109 * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
110 * PCM substream. Will be called from the PCM drivers hwparams callback.
111 * @compat_request_channel: Callback to request a DMA channel for platforms
112 * which do not use devicetree.
113 * @process: Callback used to apply processing on samples transferred from/to
114 * user space.
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 */
130 struct 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 int (*process)(struct snd_pcm_substream *substream,
138 int channel, unsigned long hwoff,
139 void *buf, unsigned long bytes);
140 dma_filter_fn compat_filter_fn;
141 struct device *dma_dev;
142 const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
143
144 const struct snd_pcm_hardware *pcm_hardware;
145 unsigned int prealloc_buffer_size;
146 };
147
148 int snd_dmaengine_pcm_register(struct device *dev,
149 const struct snd_dmaengine_pcm_config *config,
150 unsigned int flags);
151 void snd_dmaengine_pcm_unregister(struct device *dev);
152
153 int devm_snd_dmaengine_pcm_register(struct device *dev,
154 const struct snd_dmaengine_pcm_config *config,
155 unsigned int flags);
156
157 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
158 struct snd_pcm_hw_params *params,
159 struct dma_slave_config *slave_config);
160
161 #define SND_DMAENGINE_PCM_DRV_NAME "snd_dmaengine_pcm"
162
163 #endif
164