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
|
/*
* atmel-pcm-dma.c -- ALSA PCM DMA support for the Atmel SoC.
*
* Copyright (C) 2012 Atmel
*
* Author: Bo Shen <voice.shen@atmel.com>
*
* Based on atmel-pcm by:
* Sedji Gaouaou <sedji.gaouaou@atmel.com>
* Copyright 2008 Atmel
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/atmel-ssc.h>
#include <linux/platform_data/dma-atmel.h>
#include <sound/core.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
#include <sound/dmaengine_pcm.h>
#include "atmel-pcm.h"
/*--------------------------------------------------------------------------*\
* Hardware definition
\*--------------------------------------------------------------------------*/
static const struct snd_pcm_hardware atmel_pcm_dma_hardware = {
.info = SNDRV_PCM_INFO_MMAP |
SNDRV_PCM_INFO_MMAP_VALID |
SNDRV_PCM_INFO_INTERLEAVED |
SNDRV_PCM_INFO_RESUME |
SNDRV_PCM_INFO_PAUSE,
.period_bytes_min = 256, /* lighting DMA overhead */
.period_bytes_max = 2 * 0xffff, /* if 2 bytes format */
.periods_min = 8,
.periods_max = 1024, /* no limit */
.buffer_bytes_max = ATMEL_SSC_DMABUF_SIZE,
};
/**
* atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC
*
* We use DMAENGINE to send/receive data to/from SSC so this ISR is only to
* check if any overrun occured.
*/
static void atmel_pcm_dma_irq(u32 ssc_sr,
struct snd_pcm_substream *substream)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct atmel_pcm_dma_params *prtd;
prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
if (ssc_sr & prtd->mask->ssc_error) {
if (snd_pcm_running(substream))
pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n",
substream->stream == SNDRV_PCM_STREAM_PLAYBACK
? "underrun" : "overrun", prtd->name,
ssc_sr);
/* stop RX and capture: will be enabled again at restart */
ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable);
snd_pcm_stop_xrun(substream);
/* now drain RHR and read status to remove xrun condition */
ssc_readx(prtd->ssc->regs, SSC_RHR);
ssc_readx(prtd->ssc->regs, SSC_SR);
}
}
static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream,
struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
{
struct snd_soc_pcm_runtime *rtd = substream->private_data;
struct atmel_pcm_dma_params *prtd;
struct ssc_device *ssc;
int ret;
prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
ssc = prtd->ssc;
ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
if (ret) {
pr_err("atmel-pcm: hwparams to dma slave configure failed\n");
return ret;
}
if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
slave_config->dst_addr = ssc->phybase + SSC_THR;
slave_config->dst_maxburst = 1;
} else {
slave_config->src_addr = ssc->phybase + SSC_RHR;
slave_config->src_maxburst = 1;
}
prtd->dma_intr_handler = atmel_pcm_dma_irq;
return 0;
}
static const struct snd_dmaengine_pcm_config atmel_dmaengine_pcm_config = {
.prepare_slave_config = atmel_pcm_configure_dma,
.pcm_hardware = &atmel_pcm_dma_hardware,
.prealloc_buffer_size = ATMEL_SSC_DMABUF_SIZE,
};
int atmel_pcm_dma_platform_register(struct device *dev)
{
return snd_dmaengine_pcm_register(dev, &atmel_dmaengine_pcm_config,
SND_DMAENGINE_PCM_FLAG_NO_RESIDUE);
}
EXPORT_SYMBOL(atmel_pcm_dma_platform_register);
void atmel_pcm_dma_platform_unregister(struct device *dev)
{
snd_dmaengine_pcm_unregister(dev);
}
EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister);
MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
MODULE_DESCRIPTION("Atmel DMA based PCM module");
MODULE_LICENSE("GPL");
|
