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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, | |
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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 */ | |
c14e2591 | 57 | .buffer_bytes_max = 512 * 1024, |
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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 | { | |
5fe668a1 | 69 | struct snd_soc_pcm_runtime *rtd = substream->private_data; |
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70 | struct atmel_pcm_dma_params *prtd; |
71 | ||
5fe668a1 | 72 | prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); |
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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); | |
1fb8510c | 83 | snd_pcm_stop_xrun(substream); |
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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 | ||
3951e4aa | 91 | static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, |
95e0e07e | 92 | struct snd_pcm_hw_params *params, struct dma_slave_config *slave_config) |
3951e4aa | 93 | { |
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94 | struct snd_soc_pcm_runtime *rtd = substream->private_data; |
95 | struct atmel_pcm_dma_params *prtd; | |
3951e4aa | 96 | struct ssc_device *ssc; |
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97 | int ret; |
98 | ||
95e0e07e | 99 | prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); |
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100 | ssc = prtd->ssc; |
101 | ||
95e0e07e | 102 | ret = snd_hwparams_to_dma_slave_config(substream, params, slave_config); |
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103 | if (ret) { |
104 | pr_err("atmel-pcm: hwparams to dma slave configure failed\n"); | |
105 | return ret; | |
106 | } | |
107 | ||
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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; | |
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113 | |
114 | prtd->dma_intr_handler = atmel_pcm_dma_irq; | |
115 | ||
116 | return 0; | |
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117 | } |
118 | ||
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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, | |
c14e2591 | 122 | .prealloc_buffer_size = 64 * 1024, |
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123 | }; |
124 | ||
125 | int atmel_pcm_dma_platform_register(struct device *dev) | |
126 | { | |
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127 | return snd_dmaengine_pcm_register(dev, &atmel_dmaengine_pcm_config, |
128 | SND_DMAENGINE_PCM_FLAG_NO_RESIDUE); | |
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129 | } |
130 | EXPORT_SYMBOL(atmel_pcm_dma_platform_register); | |
131 | ||
132 | void atmel_pcm_dma_platform_unregister(struct device *dev) | |
133 | { | |
95e0e07e | 134 | snd_dmaengine_pcm_unregister(dev); |
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135 | } |
136 | EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister); | |
137 | ||
138 | MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); | |
139 | MODULE_DESCRIPTION("Atmel DMA based PCM module"); | |
140 | MODULE_LICENSE("GPL"); |