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  * @peripheral_config: peripheral configuration for programming peripheral
70  * for dmaengine transfer
71  * @peripheral_size: peripheral configuration buffer size
72  */
73 struct snd_dmaengine_dai_dma_data {
74 	dma_addr_t addr;
75 	enum dma_slave_buswidth addr_width;
76 	u32 maxburst;
77 	unsigned int slave_id;
78 	void *filter_data;
79 	const char *chan_name;
80 	unsigned int fifo_size;
81 	unsigned int flags;
82 	void *peripheral_config;
83 	size_t peripheral_size;
84 };
85 
86 void snd_dmaengine_pcm_set_config_from_dai_data(
87 	const struct snd_pcm_substream *substream,
88 	const struct snd_dmaengine_dai_dma_data *dma_data,
89 	struct dma_slave_config *config);
90 
91 int snd_dmaengine_pcm_refine_runtime_hwparams(
92 	struct snd_pcm_substream *substream,
93 	struct snd_dmaengine_dai_dma_data *dma_data,
94 	struct snd_pcm_hardware *hw,
95 	struct dma_chan *chan);
96 
97 /*
98  * Try to request the DMA channel using compat_request_channel or
99  * compat_filter_fn if it couldn't be requested through devicetree.
100  */
101 #define SND_DMAENGINE_PCM_FLAG_COMPAT BIT(0)
102 /*
103  * Don't try to request the DMA channels through devicetree. This flag only
104  * makes sense if SND_DMAENGINE_PCM_FLAG_COMPAT is set as well.
105  */
106 #define SND_DMAENGINE_PCM_FLAG_NO_DT BIT(1)
107 /*
108  * The PCM is half duplex and the DMA channel is shared between capture and
109  * playback.
110  */
111 #define SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX BIT(3)
112 
113 /**
114  * struct snd_dmaengine_pcm_config - Configuration data for dmaengine based PCM
115  * @prepare_slave_config: Callback used to fill in the DMA slave_config for a
116  *   PCM substream. Will be called from the PCM drivers hwparams callback.
117  * @compat_request_channel: Callback to request a DMA channel for platforms
118  *   which do not use devicetree.
119  * @process: Callback used to apply processing on samples transferred from/to
120  *   user space.
121  * @compat_filter_fn: Will be used as the filter function when requesting a
122  *  channel for platforms which do not use devicetree. The filter parameter
123  *  will be the DAI's DMA data.
124  * @dma_dev: If set, request DMA channel on this device rather than the DAI
125  *  device.
126  * @chan_names: If set, these custom DMA channel names will be requested at
127  *  registration time.
128  * @pcm_hardware: snd_pcm_hardware struct to be used for the PCM.
129  * @prealloc_buffer_size: Size of the preallocated audio buffer.
130  *
131  * Note: If both compat_request_channel and compat_filter_fn are set
132  * compat_request_channel will be used to request the channel and
133  * compat_filter_fn will be ignored. Otherwise the channel will be requested
134  * using dma_request_channel with compat_filter_fn as the filter function.
135  */
136 struct snd_dmaengine_pcm_config {
137 	int (*prepare_slave_config)(struct snd_pcm_substream *substream,
138 			struct snd_pcm_hw_params *params,
139 			struct dma_slave_config *slave_config);
140 	struct dma_chan *(*compat_request_channel)(
141 			struct snd_soc_pcm_runtime *rtd,
142 			struct snd_pcm_substream *substream);
143 	int (*process)(struct snd_pcm_substream *substream,
144 		       int channel, unsigned long hwoff,
145 		       void *buf, unsigned long bytes);
146 	dma_filter_fn compat_filter_fn;
147 	struct device *dma_dev;
148 	const char *chan_names[SNDRV_PCM_STREAM_LAST + 1];
149 
150 	const struct snd_pcm_hardware *pcm_hardware;
151 	unsigned int prealloc_buffer_size;
152 };
153 
154 int snd_dmaengine_pcm_register(struct device *dev,
155 	const struct snd_dmaengine_pcm_config *config,
156 	unsigned int flags);
157 void snd_dmaengine_pcm_unregister(struct device *dev);
158 
159 int devm_snd_dmaengine_pcm_register(struct device *dev,
160 	const struct snd_dmaengine_pcm_config *config,
161 	unsigned int flags);
162 
163 int snd_dmaengine_pcm_prepare_slave_config(struct snd_pcm_substream *substream,
164 	struct snd_pcm_hw_params *params,
165 	struct dma_slave_config *slave_config);
166 
167 #define SND_DMAENGINE_PCM_DRV_NAME "snd_dmaengine_pcm"
168 
169 struct dmaengine_pcm {
170 	struct dma_chan *chan[SNDRV_PCM_STREAM_LAST + 1];
171 	const struct snd_dmaengine_pcm_config *config;
172 	struct snd_soc_component component;
173 	unsigned int flags;
174 };
175 
soc_component_to_pcm(struct snd_soc_component * p)176 static inline struct dmaengine_pcm *soc_component_to_pcm(struct snd_soc_component *p)
177 {
178 	return container_of(p, struct dmaengine_pcm, component);
179 }
180 #endif
181