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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 | { | |
70 | struct atmel_pcm_dma_params *prtd; | |
71 | ||
72 | prtd = snd_dmaengine_pcm_get_data(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(substream, SNDRV_PCM_STATE_XRUN); | |
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 | /*--------------------------------------------------------------------------*\ | |
92 | * DMAENGINE operations | |
93 | \*--------------------------------------------------------------------------*/ | |
94 | static bool filter(struct dma_chan *chan, void *slave) | |
95 | { | |
96 | struct at_dma_slave *sl = slave; | |
97 | ||
98 | if (sl->dma_dev == chan->device->dev) { | |
99 | chan->private = sl; | |
100 | return true; | |
101 | } else { | |
102 | return false; | |
103 | } | |
104 | } | |
105 | ||
106 | static int atmel_pcm_configure_dma(struct snd_pcm_substream *substream, | |
107 | struct snd_pcm_hw_params *params) | |
108 | { | |
109 | struct atmel_pcm_dma_params *prtd; | |
110 | struct ssc_device *ssc; | |
111 | struct dma_chan *dma_chan; | |
112 | struct dma_slave_config slave_config; | |
113 | int ret; | |
114 | ||
115 | prtd = snd_dmaengine_pcm_get_data(substream); | |
116 | ssc = prtd->ssc; | |
117 | ||
118 | ret = snd_hwparams_to_dma_slave_config(substream, params, | |
119 | &slave_config); | |
120 | if (ret) { | |
121 | pr_err("atmel-pcm: hwparams to dma slave configure failed\n"); | |
122 | return ret; | |
123 | } | |
124 | ||
125 | if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { | |
126 | slave_config.dst_addr = (dma_addr_t)ssc->phybase + SSC_THR; | |
127 | slave_config.dst_maxburst = 1; | |
128 | } else { | |
129 | slave_config.src_addr = (dma_addr_t)ssc->phybase + SSC_RHR; | |
130 | slave_config.src_maxburst = 1; | |
131 | } | |
132 | ||
133 | slave_config.device_fc = false; | |
134 | ||
135 | dma_chan = snd_dmaengine_pcm_get_chan(substream); | |
136 | if (dmaengine_slave_config(dma_chan, &slave_config)) { | |
137 | pr_err("atmel-pcm: failed to configure dma channel\n"); | |
138 | ret = -EBUSY; | |
139 | return ret; | |
140 | } | |
141 | ||
142 | return 0; | |
143 | } | |
144 | ||
145 | static int atmel_pcm_hw_params(struct snd_pcm_substream *substream, | |
146 | struct snd_pcm_hw_params *params) | |
147 | { | |
148 | struct snd_soc_pcm_runtime *rtd = substream->private_data; | |
149 | struct atmel_pcm_dma_params *prtd; | |
150 | struct ssc_device *ssc; | |
151 | struct at_dma_slave *sdata = NULL; | |
152 | int ret; | |
153 | ||
154 | snd_pcm_set_runtime_buffer(substream, &substream->dma_buffer); | |
155 | ||
156 | prtd = snd_soc_dai_get_dma_data(rtd->cpu_dai, substream); | |
157 | ssc = prtd->ssc; | |
158 | if (ssc->pdev) | |
159 | sdata = ssc->pdev->dev.platform_data; | |
160 | ||
161 | ret = snd_dmaengine_pcm_open(substream, filter, sdata); | |
162 | if (ret) { | |
163 | pr_err("atmel-pcm: dmaengine pcm open failed\n"); | |
164 | return -EINVAL; | |
165 | } | |
166 | ||
167 | snd_dmaengine_pcm_set_data(substream, prtd); | |
168 | ||
169 | ret = atmel_pcm_configure_dma(substream, params); | |
170 | if (ret) { | |
171 | pr_err("atmel-pcm: failed to configure dmai\n"); | |
172 | goto err; | |
173 | } | |
174 | ||
175 | prtd->dma_intr_handler = atmel_pcm_dma_irq; | |
176 | ||
177 | return 0; | |
178 | err: | |
179 | snd_dmaengine_pcm_close(substream); | |
180 | return ret; | |
181 | } | |
182 | ||
183 | static int atmel_pcm_dma_prepare(struct snd_pcm_substream *substream) | |
184 | { | |
185 | struct atmel_pcm_dma_params *prtd; | |
186 | ||
187 | prtd = snd_dmaengine_pcm_get_data(substream); | |
188 | ||
189 | ssc_writex(prtd->ssc->regs, SSC_IER, prtd->mask->ssc_error); | |
190 | ssc_writex(prtd->ssc->regs, SSC_CR, prtd->mask->ssc_enable); | |
191 | ||
192 | return 0; | |
193 | } | |
194 | ||
195 | static int atmel_pcm_open(struct snd_pcm_substream *substream) | |
196 | { | |
197 | snd_soc_set_runtime_hwparams(substream, &atmel_pcm_dma_hardware); | |
198 | ||
199 | return 0; | |
200 | } | |
201 | ||
3951e4aa BS |
202 | static struct snd_pcm_ops atmel_pcm_ops = { |
203 | .open = atmel_pcm_open, | |
a85fc1b0 | 204 | .close = snd_dmaengine_pcm_close, |
3951e4aa BS |
205 | .ioctl = snd_pcm_lib_ioctl, |
206 | .hw_params = atmel_pcm_hw_params, | |
207 | .prepare = atmel_pcm_dma_prepare, | |
208 | .trigger = snd_dmaengine_pcm_trigger, | |
209 | .pointer = snd_dmaengine_pcm_pointer_no_residue, | |
210 | .mmap = atmel_pcm_mmap, | |
211 | }; | |
212 | ||
213 | static struct snd_soc_platform_driver atmel_soc_platform = { | |
214 | .ops = &atmel_pcm_ops, | |
215 | .pcm_new = atmel_pcm_new, | |
216 | .pcm_free = atmel_pcm_free, | |
217 | }; | |
218 | ||
219 | int atmel_pcm_dma_platform_register(struct device *dev) | |
220 | { | |
221 | return snd_soc_register_platform(dev, &atmel_soc_platform); | |
222 | } | |
223 | EXPORT_SYMBOL(atmel_pcm_dma_platform_register); | |
224 | ||
225 | void atmel_pcm_dma_platform_unregister(struct device *dev) | |
226 | { | |
227 | snd_soc_unregister_platform(dev); | |
228 | } | |
229 | EXPORT_SYMBOL(atmel_pcm_dma_platform_unregister); | |
230 | ||
231 | MODULE_AUTHOR("Bo Shen <voice.shen@atmel.com>"); | |
232 | MODULE_DESCRIPTION("Atmel DMA based PCM module"); | |
233 | MODULE_LICENSE("GPL"); |