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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, | |
53 | .formats = SNDRV_PCM_FMTBIT_S16_LE, | |
54 | .period_bytes_min = 256, /* lighting DMA overhead */ | |
55 | .period_bytes_max = 2 * 0xffff, /* if 2 bytes format */ | |
56 | .periods_min = 8, | |
57 | .periods_max = 1024, /* no limit */ | |
58 | .buffer_bytes_max = ATMEL_SSC_DMABUF_SIZE, | |
59 | }; | |
60 | ||
61 | /** | |
62 | * atmel_pcm_dma_irq: SSC interrupt handler for DMAENGINE enabled SSC | |
63 | * | |
64 | * We use DMAENGINE to send/receive data to/from SSC so this ISR is only to | |
65 | * check if any overrun occured. | |
66 | */ | |
67 | static void atmel_pcm_dma_irq(u32 ssc_sr, | |
68 | struct snd_pcm_substream *substream) | |
69 | { | |
5fe668a1 | 70 | struct snd_soc_pcm_runtime *rtd = substream->private_data; |
3951e4aa BS |
71 | struct atmel_pcm_dma_params *prtd; |
72 | ||
5fe668a1 | 73 | prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); |
3951e4aa BS |
74 | |
75 | if (ssc_sr & prtd->mask->ssc_error) { | |
76 | if (snd_pcm_running(substream)) | |
77 | pr_warn("atmel-pcm: buffer %s on %s (SSC_SR=%#x)\n", | |
78 | substream->stream == SNDRV_PCM_STREAM_PLAYBACK | |
79 | ? "underrun" : "overrun", prtd->name, | |
80 | ssc_sr); | |
81 | ||
82 | /* stop RX and capture: will be enabled again at restart */ | |
83 | ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_disable); | |
84 | snd_pcm_stop(substream, SNDRV_PCM_STATE_XRUN); | |
85 | ||
86 | /* now drain RHR and read status to remove xrun condition */ | |
87 | ssc_readx(prtd->ssc->regs, SSC_RHR); | |
88 | ssc_readx(prtd->ssc->regs, SSC_SR); | |
89 | } | |
90 | } | |
91 | ||
92 | /*--------------------------------------------------------------------------*\ | |
93 | * DMAENGINE operations | |
94 | \*--------------------------------------------------------------------------*/ | |
95 | static bool filter(struct dma_chan *chan, void *slave) | |
96 | { | |
97 | struct at_dma_slave *sl = slave; | |
98 | ||
99 | if (sl->dma_dev == chan->device->dev) { | |
100 | chan->private = sl; | |
101 | return true; | |
102 | } else { | |
103 | return false; | |
104 | } | |
105 | } | |
106 | ||
107 | static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, | |
5fe668a1 | 108 | struct snd_pcm_hw_params *params, struct atmel_pcm_dma_params *prtd) |
3951e4aa | 109 | { |
3951e4aa BS |
110 | struct ssc_device *ssc; |
111 | struct dma_chan *dma_chan; | |
112 | struct dma_slave_config slave_config; | |
113 | int ret; | |
114 | ||
3951e4aa BS |
115 | ssc = prtd->ssc; |
116 | ||
117 | ret = snd_hwparams_to_dma_slave_config(substream, params, | |
118 | &slave_config); | |
119 | if (ret) { | |
120 | pr_err("atmel-pcm: hwparams to dma slave configure failed\n"); | |
121 | return ret; | |
122 | } | |
123 | ||
124 | if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { | |
125 | slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR; | |
126 | slave_config.dst_maxburst = 1; | |
127 | } else { | |
128 | slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR; | |
129 | slave_config.src_maxburst = 1; | |
130 | } | |
131 | ||
3951e4aa BS |
132 | dma_chan = snd_dmaengine_pcm_get_chan(substream); |
133 | if (dmaengine_slave_config(dma_chan, &slave_config)) { | |
134 | pr_err("atmel-pcm: failed to configure dma channel\n"); | |
135 | ret = -EBUSY; | |
136 | return ret; | |
137 | } | |
138 | ||
139 | return 0; | |
140 | } | |
141 | ||
142 | static int atmel_pcm_hw_params(struct snd_pcm_substream *substream, | |
143 | struct snd_pcm_hw_params *params) | |
144 | { | |
145 | struct snd_soc_pcm_runtime *rtd = substream->private_data; | |
146 | struct atmel_pcm_dma_params *prtd; | |
147 | struct ssc_device *ssc; | |
148 | struct at_dma_slave *sdata = NULL; | |
149 | int ret; | |
150 | ||
151 | snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer); | |
152 | ||
153 | prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); | |
154 | ssc = prtd->ssc; | |
155 | if (ssc->pdev) | |
156 | sdata = ssc->pdev->dev.platform_data; | |
157 | ||
158 | ret = snd_dmaengine_pcm_open(substream, filter, sdata); | |
159 | if (ret) { | |
160 | pr_err("atmel-pcm: dmaengine pcm open failed\n"); | |
161 | return -EINVAL; | |
162 | } | |
163 | ||
5fe668a1 | 164 | ret = atmel_pcm_configure_dma(substream, params, prtd); |
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165 | if (ret) { |
166 | pr_err("atmel-pcm: failed to configure dmai\n"); | |
167 | goto err; | |
168 | } | |
169 | ||
170 | prtd->dma_intr_handler = atmel_pcm_dma_irq; | |
171 | ||
172 | return 0; | |
173 | err: | |
174 | snd_dmaengine_pcm_close(substream); | |
175 | return ret; | |
176 | } | |
177 | ||
178 | static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream) | |
179 | { | |
5fe668a1 | 180 | struct snd_soc_pcm_runtime *rtd = substream->private_data; |
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181 | struct atmel_pcm_dma_params *prtd; |
182 | ||
5fe668a1 | 183 | prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); |
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184 | |
185 | ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error); | |
186 | ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable); | |
187 | ||
188 | return 0; | |
189 | } | |
190 | ||
191 | static int atmel_pcm_open(struct snd_pcm_substream *substream) | |
192 | { | |
193 | snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware); | |
194 | ||
195 | return 0; | |
196 | } | |
197 | ||
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198 | static struct snd_pcm_ops atmel_pcm_ops = { |
199 | .open = atmel_pcm_open, | |
a85fc1b0 | 200 | .close = snd_dmaengine_pcm_close, |
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201 | .ioctl = snd_pcm_lib_ioctl, |
202 | .hw_params = atmel_pcm_hw_params, | |
203 | .prepare = atmel_pcm_dma_prepare, | |
204 | .trigger = snd_dmaengine_pcm_trigger, | |
205 | .pointer = snd_dmaengine_pcm_pointer_no_residue, | |
206 | .mmap = atmel_pcm_mmap, | |
207 | }; | |
208 | ||
209 | static struct snd_soc_platform_driver atmel_soc_platform = { | |
210 | .ops = &atmel_pcm_ops, | |
211 | .pcm_new = atmel_pcm_new, | |
212 | .pcm_free = atmel_pcm_free, | |
213 | }; | |
214 | ||
215 | int atmel_pcm_dma_platform_register(struct device *dev) | |
216 | { | |
217 | return snd_soc_register_platform(dev, &atmel_soc_platform); | |
218 | } | |
219 | EXPORT_SYMBOL(atmel_pcm_dma_platform_register); | |
220 | ||
221 | void atmel_pcm_dma_platform_unregister(struct device *dev) | |
222 | { | |
223 | snd_soc_unregister_platform(dev); | |
224 | } | |
225 | EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister); | |
226 | ||
227 | MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); | |
228 | MODULE_DESCRIPTION("Atmel DMA based PCM module"); | |
229 | MODULE_LICENSE("GPL"); |