aboutsummaryrefslogtreecommitdiff
path: root/sound/soc/soc-dmaengine-pcm.c
blob: 475695234b3d2f37d843e34e2c3e8caa4df0b4c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
/*
 *  Copyright (C) 2012, Analog Devices Inc.
 *	Author: Lars-Peter Clausen <lars@metafoo.de>
 *
 *  Based on:
 *	imx-pcm-dma-mx2.c, Copyright 2009 Sascha Hauer <s.hauer@pengutronix.de>
 *	mxs-pcm.c, Copyright (C) 2011 Freescale Semiconductor, Inc.
 *	ep93xx-pcm.c, Copyright (C) 2006 Lennert Buytenhek <buytenh@wantstofly.org>
 *		      Copyright (C) 2006 Applied Data Systems
 *
 *  This program is free software; you can redistribute it and/or modify it
 *  under  the terms of the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the License, or (at your
 *  option) any later version.
 *
 *  You should have received a copy of the GNU General Public License along
 *  with this program; if not, write to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dmaengine.h>
#include <linux/slab.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>

#include <sound/dmaengine_pcm.h>

struct dmaengine_pcm_runtime_data {
	struct dma_chan *dma_chan;

	unsigned int pos;

	void *data;
};

static inline struct dmaengine_pcm_runtime_data *substream_to_prtd(
	const struct snd_pcm_substream *substream)
{
	return substream->runtime->private_data;
}

/**
 * snd_dmaengine_pcm_set_data - Set dmaengine substream private data
 * @substream: PCM substream
 * @data: Data to set
 */
void snd_dmaengine_pcm_set_data(struct snd_pcm_substream *substream, void *data)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	prtd->data = data;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_set_data);

/**
 * snd_dmaengine_pcm_get_data - Get dmaeinge substream private data
 * @substream: PCM substream
 *
 * Returns the data previously set with snd_dmaengine_pcm_set_data
 */
void *snd_dmaengine_pcm_get_data(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	return prtd->data;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_data);

struct dma_chan *snd_dmaengine_pcm_get_chan(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	return prtd->dma_chan;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_get_chan);

/**
 * snd_hwparams_to_dma_slave_config - Convert hw_params to dma_slave_config
 * @substream: PCM substream
 * @params: hw_params
 * @slave_config: DMA slave config
 *
 * This function can be used to initialize a dma_slave_config from a substream
 * and hw_params in a dmaengine based PCM driver implementation.
 */
int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream,
	const struct snd_pcm_hw_params *params,
	struct dma_slave_config *slave_config)
{
	enum dma_slave_buswidth buswidth;

	switch (params_format(params)) {
	case SNDRV_PCM_FORMAT_S8:
		buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE;
		break;
	case SNDRV_PCM_FORMAT_S16_LE:
		buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES;
		break;
	case SNDRV_PCM_FORMAT_S18_3LE:
	case SNDRV_PCM_FORMAT_S20_3LE:
	case SNDRV_PCM_FORMAT_S24_LE:
	case SNDRV_PCM_FORMAT_S32_LE:
		buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES;
		break;
	default:
		return -EINVAL;
	}

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
		slave_config->direction = DMA_MEM_TO_DEV;
		slave_config->dst_addr_width = buswidth;
	} else {
		slave_config->direction = DMA_DEV_TO_MEM;
		slave_config->src_addr_width = buswidth;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(snd_hwparams_to_dma_slave_config);

static void dmaengine_pcm_dma_complete(void *arg)
{
	struct snd_pcm_substream *substream = arg;
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	prtd->pos += snd_pcm_lib_period_bytes(substream);
	if (prtd->pos >= snd_pcm_lib_buffer_bytes(substream))
		prtd->pos = 0;

	snd_pcm_period_elapsed(substream);
}

static int dmaengine_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	struct dma_chan *chan = prtd->dma_chan;
	struct dma_async_tx_descriptor *desc;
	enum dma_transfer_direction direction;

	direction = snd_pcm_substream_to_dma_direction(substream);

	prtd->pos = 0;
	desc = dmaengine_prep_dma_cyclic(chan,
		substream->runtime->dma_addr,
		snd_pcm_lib_buffer_bytes(substream),
		snd_pcm_lib_period_bytes(substream), direction);

	if (!desc)
		return -ENOMEM;

	desc->callback = dmaengine_pcm_dma_complete;
	desc->callback_param = substream;
	dmaengine_submit(desc);

	return 0;
}

/**
 * snd_dmaengine_pcm_trigger - dmaengine based PCM trigger implementation
 * @substream: PCM substream
 * @cmd: Trigger command
 *
 * Returns 0 on success, a negative error code otherwise.
 *
 * This function can be used as the PCM trigger callback for dmaengine based PCM
 * driver implementations.
 */
int snd_dmaengine_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	int ret;

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
		ret = dmaengine_pcm_prepare_and_submit(substream);
		if (ret)
			return ret;
		dma_async_issue_pending(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		dmaengine_resume(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		dmaengine_pause(prtd->dma_chan);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
		dmaengine_terminate_all(prtd->dma_chan);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_trigger);

/**
 * snd_dmaengine_pcm_pointer - dmaengine based PCM pointer implementation
 * @substream: PCM substream
 *
 * This function can be used as the PCM pointer callback for dmaengine based PCM
 * driver implementations.
 */
snd_pcm_uframes_t snd_dmaengine_pcm_pointer(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
	return bytes_to_frames(substream->runtime, prtd->pos);
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_pointer);

static int dmaengine_pcm_request_channel(struct dmaengine_pcm_runtime_data *prtd,
	dma_filter_fn filter_fn, void *filter_data)
{
	dma_cap_mask_t mask;

	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);
	dma_cap_set(DMA_CYCLIC, mask);
	prtd->dma_chan = dma_request_channel(mask, filter_fn, filter_data);

	if (!prtd->dma_chan)
		return -ENXIO;

	return 0;
}

/**
 * snd_dmaengine_pcm_open - Open a dmaengine based PCM substream
 * @substream: PCM substream
 * @filter_fn: Filter function used to request the DMA channel
 * @filter_data: Data passed to the DMA filter function
 *
 * Returns 0 on success, a negative error code otherwise.
 *
 * This function will request a DMA channel using the passed filter function and
 * data. The function should usually be called from the pcm open callback.
 *
 * Note that this function will use private_data field of the substream's
 * runtime. So it is not availabe to your pcm driver implementation. If you need
 * to keep additional data attached to a substream use
 * snd_dmaeinge_pcm_{set,get}_data.
 */
int snd_dmaengine_pcm_open(struct snd_pcm_substream *substream,
	dma_filter_fn filter_fn, void *filter_data)
{
	struct dmaengine_pcm_runtime_data *prtd;
	int ret;

	ret = snd_pcm_hw_constraint_integer(substream->runtime,
					    SNDRV_PCM_HW_PARAM_PERIODS);
	if (ret < 0)
		return ret;

	prtd = kzalloc(sizeof(*prtd), GFP_KERNEL);
	if (!prtd)
		return -ENOMEM;

	ret = dmaengine_pcm_request_channel(prtd, filter_fn, filter_data);
	if (ret < 0) {
		kfree(prtd);
		return ret;
	}

	substream->runtime->private_data = prtd;

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_open);

/**
 * snd_dmaengine_pcm_close - Close a dmaengine based PCM substream
 * @substream: PCM substream
 */
int snd_dmaengine_pcm_close(struct snd_pcm_substream *substream)
{
	struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);

	dma_release_channel(prtd->dma_chan);
	kfree(prtd);

	return 0;
}
EXPORT_SYMBOL_GPL(snd_dmaengine_pcm_close);