This patch contains scripts to decrease the time taken for
[kvmfornfv.git] / kernel / sound / soc / atmel / atmel-pcm-dma.c
1 /*
2  * atmel-pcm-dma.c  --  ALSA PCM DMA support for the Atmel SoC.
3  *
4  *  Copyright (C) 2012 Atmel
5  *
6  * Author: Bo Shen <voice.shen@atmel.com>
7  *
8  * Based on atmel-pcm by:
9  * Sedji Gaouaou <sedji.gaouaou@atmel.com>
10  * Copyright 2008 Atmel
11  *
12  * This program is free software; you can redistribute it and/or modify
13  * it under the terms of the GNU General Public License as published by
14  * the Free Software Foundation; either version 2 of the License, or
15  * (at your option) any later version.
16  *
17  * This program is distributed in the hope that it will be useful,
18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  * GNU General Public License for more details.
21  *
22  * You should have received a copy of the GNU General Public License
23  * along with this program; if not, write to the Free Software
24  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
25  */
26
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/platform_device.h>
30 #include <linux/slab.h>
31 #include <linux/dma-mapping.h>
32 #include <linux/dmaengine.h>
33 #include <linux/atmel-ssc.h>
34 #include <linux/platform_data/dma-atmel.h>
35
36 #include <sound/core.h>
37 #include <sound/pcm.h>
38 #include <sound/pcm_params.h>
39 #include <sound/soc.h>
40 #include <sound/dmaengine_pcm.h>
41
42 #include "atmel-pcm.h"
43
44 /*--------------------------------------------------------------------------*\
45  * Hardware definition
46 \*--------------------------------------------------------------------------*/
47 static const struct snd_pcm_hardware atmel_pcm_dma_hardware = {
48         .info                   = SNDRV_PCM_INFO_MMAP |
49                                   SNDRV_PCM_INFO_MMAP_VALID |
50                                   SNDRV_PCM_INFO_INTERLEAVED |
51                                   SNDRV_PCM_INFO_RESUME |
52                                   SNDRV_PCM_INFO_PAUSE,
53         .period_bytes_min       = 256,          /* lighting DMA overhead */
54         .period_bytes_max       = 2 * 0xffff,   /* if 2 bytes format */
55         .periods_min            = 8,
56         .periods_max            = 1024,         /* no limit */
57         .buffer_bytes_max       = 512 * 1024,
58 };
59
60 /**
61  * atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC
62  *
63  * We use DMAENGINE to send/receive data to/from SSC so this ISR is only to
64  * check if any overrun occured.
65  */
66 static void atmel_pcm_dma_irq(u32 ssc_sr,
67         struct snd_pcm_substream *substream)
68 {
69         struct snd_soc_pcm_runtime *rtd = substream->private_data;
70         struct atmel_pcm_dma_params *prtd;
71
72         prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
73
74         if (ssc_sr & prtd->mask->ssc_error) {
75                 if (snd_pcm_running(substream))
76                         pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n",
77                                 substream->stream == SNDRV_PCM_STREAM_PLAYBACK
78                                 ? "underrun" : "overrun", prtd->name,
79                                 ssc_sr);
80
81                 /* stop RX and capture: will be enabled again at restart */
82                 ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable);
83                 snd_pcm_stop_xrun(substream);
84
85                 /* now drain RHR and read status to remove xrun condition */
86                 ssc_readx(prtd->ssc->regs, SSC_RHR);
87                 ssc_readx(prtd->ssc->regs, SSC_SR);
88         }
89 }
90
91 static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream,
92         struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config)
93 {
94         struct snd_soc_pcm_runtime *rtd = substream->private_data;
95         struct atmel_pcm_dma_params *prtd;
96         struct ssc_device *ssc;
97         int ret;
98
99         prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream);
100         ssc = prtd->ssc;
101
102         ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config);
103         if (ret) {
104                 pr_err("atmel-pcm: hwparams to dma slave configure failed\n");
105                 return ret;
106         }
107
108         slave_config->dst_addr = ssc->phybase + SSC_THR;
109         slave_config->dst_maxburst = 1;
110
111         slave_config->src_addr = ssc->phybase + SSC_RHR;
112         slave_config->src_maxburst = 1;
113
114         prtd->dma_intr_handler = atmel_pcm_dma_irq;
115
116         return 0;
117 }
118
119 static const struct snd_dmaengine_pcm_config atmel_dmaengine_pcm_config = {
120         .prepare_slave_config = atmel_pcm_configure_dma,
121         .pcm_hardware = &atmel_pcm_dma_hardware,
122         .prealloc_buffer_size = 64 * 1024,
123 };
124
125 int atmel_pcm_dma_platform_register(struct device *dev)
126 {
127         return snd_dmaengine_pcm_register(dev, &atmel_dmaengine_pcm_config, 0);
128 }
129 EXPORT_SYMBOL(atmel_pcm_dma_platform_register);
130
131 void atmel_pcm_dma_platform_unregister(struct device *dev)
132 {
133         snd_dmaengine_pcm_unregister(dev);
134 }
135 EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister);
136
137 MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>");
138 MODULE_DESCRIPTION("Atmel DMA based PCM module");
139 MODULE_LICENSE("GPL");