1 /*
2  * tegra_spdif.c - Tegra SPDIF driver
3  *
4  * Author: Stephen Warren <swarren@nvidia.com>
5  * Copyright (C) 2011 - NVIDIA, Inc.
6  *
7  * This program is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU General Public License
9  * version 2 as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope that it will be useful, but
12  * WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19  * 02110-1301 USA
20  *
21  */
22 
23 #include <linux/clk.h>
24 #include <linux/module.h>
25 #include <linux/debugfs.h>
26 #include <linux/device.h>
27 #include <linux/platform_device.h>
28 #include <linux/seq_file.h>
29 #include <linux/slab.h>
30 #include <linux/io.h>
31 #include <mach/iomap.h>
32 #include <sound/core.h>
33 #include <sound/pcm.h>
34 #include <sound/pcm_params.h>
35 #include <sound/soc.h>
36 
37 #include "tegra_spdif.h"
38 
39 #define DRV_NAME "tegra-spdif"
40 
tegra_spdif_write(struct tegra_spdif * spdif,u32 reg,u32 val)41 static inline void tegra_spdif_write(struct tegra_spdif *spdif, u32 reg,
42 					u32 val)
43 {
44 	__raw_writel(val, spdif->regs + reg);
45 }
46 
tegra_spdif_read(struct tegra_spdif * spdif,u32 reg)47 static inline u32 tegra_spdif_read(struct tegra_spdif *spdif, u32 reg)
48 {
49 	return __raw_readl(spdif->regs + reg);
50 }
51 
52 #ifdef CONFIG_DEBUG_FS
tegra_spdif_show(struct seq_file * s,void * unused)53 static int tegra_spdif_show(struct seq_file *s, void *unused)
54 {
55 #define REG(r) { r, #r }
56 	static const struct {
57 		int offset;
58 		const char *name;
59 	} regs[] = {
60 		REG(TEGRA_SPDIF_CTRL),
61 		REG(TEGRA_SPDIF_STATUS),
62 		REG(TEGRA_SPDIF_STROBE_CTRL),
63 		REG(TEGRA_SPDIF_DATA_FIFO_CSR),
64 		REG(TEGRA_SPDIF_CH_STA_RX_A),
65 		REG(TEGRA_SPDIF_CH_STA_RX_B),
66 		REG(TEGRA_SPDIF_CH_STA_RX_C),
67 		REG(TEGRA_SPDIF_CH_STA_RX_D),
68 		REG(TEGRA_SPDIF_CH_STA_RX_E),
69 		REG(TEGRA_SPDIF_CH_STA_RX_F),
70 		REG(TEGRA_SPDIF_CH_STA_TX_A),
71 		REG(TEGRA_SPDIF_CH_STA_TX_B),
72 		REG(TEGRA_SPDIF_CH_STA_TX_C),
73 		REG(TEGRA_SPDIF_CH_STA_TX_D),
74 		REG(TEGRA_SPDIF_CH_STA_TX_E),
75 		REG(TEGRA_SPDIF_CH_STA_TX_F),
76 	};
77 #undef REG
78 
79 	struct tegra_spdif *spdif = s->private;
80 	int i;
81 
82 	for (i = 0; i < ARRAY_SIZE(regs); i++) {
83 		u32 val = tegra_spdif_read(spdif, regs[i].offset);
84 		seq_printf(s, "%s = %08x\n", regs[i].name, val);
85 	}
86 
87 	return 0;
88 }
89 
tegra_spdif_debug_open(struct inode * inode,struct file * file)90 static int tegra_spdif_debug_open(struct inode *inode, struct file *file)
91 {
92 	return single_open(file, tegra_spdif_show, inode->i_private);
93 }
94 
95 static const struct file_operations tegra_spdif_debug_fops = {
96 	.open    = tegra_spdif_debug_open,
97 	.read    = seq_read,
98 	.llseek  = seq_lseek,
99 	.release = single_release,
100 };
101 
tegra_spdif_debug_add(struct tegra_spdif * spdif)102 static void tegra_spdif_debug_add(struct tegra_spdif *spdif)
103 {
104 	spdif->debug = debugfs_create_file(DRV_NAME, S_IRUGO,
105 						snd_soc_debugfs_root, spdif,
106 						&tegra_spdif_debug_fops);
107 }
108 
tegra_spdif_debug_remove(struct tegra_spdif * spdif)109 static void tegra_spdif_debug_remove(struct tegra_spdif *spdif)
110 {
111 	if (spdif->debug)
112 		debugfs_remove(spdif->debug);
113 }
114 #else
tegra_spdif_debug_add(struct tegra_spdif * spdif)115 static inline void tegra_spdif_debug_add(struct tegra_spdif *spdif)
116 {
117 }
118 
tegra_spdif_debug_remove(struct tegra_spdif * spdif)119 static inline void tegra_spdif_debug_remove(struct tegra_spdif *spdif)
120 {
121 }
122 #endif
123 
tegra_spdif_hw_params(struct snd_pcm_substream * substream,struct snd_pcm_hw_params * params,struct snd_soc_dai * dai)124 static int tegra_spdif_hw_params(struct snd_pcm_substream *substream,
125 				struct snd_pcm_hw_params *params,
126 				struct snd_soc_dai *dai)
127 {
128 	struct device *dev = substream->pcm->card->dev;
129 	struct tegra_spdif *spdif = snd_soc_dai_get_drvdata(dai);
130 	int ret, spdifclock;
131 
132 	spdif->reg_ctrl &= ~TEGRA_SPDIF_CTRL_PACK;
133 	spdif->reg_ctrl &= ~TEGRA_SPDIF_CTRL_BIT_MODE_MASK;
134 	switch (params_format(params)) {
135 	case SNDRV_PCM_FORMAT_S16_LE:
136 		spdif->reg_ctrl |= TEGRA_SPDIF_CTRL_PACK;
137 		spdif->reg_ctrl |= TEGRA_SPDIF_CTRL_BIT_MODE_16BIT;
138 		break;
139 	default:
140 		return -EINVAL;
141 	}
142 
143 	switch (params_rate(params)) {
144 	case 32000:
145 		spdifclock = 4096000;
146 		break;
147 	case 44100:
148 		spdifclock = 5644800;
149 		break;
150 	case 48000:
151 		spdifclock = 6144000;
152 		break;
153 	case 88200:
154 		spdifclock = 11289600;
155 		break;
156 	case 96000:
157 		spdifclock = 12288000;
158 		break;
159 	case 176400:
160 		spdifclock = 22579200;
161 		break;
162 	case 192000:
163 		spdifclock = 24576000;
164 		break;
165 	default:
166 		return -EINVAL;
167 	}
168 
169 	ret = clk_set_rate(spdif->clk_spdif_out, spdifclock);
170 	if (ret) {
171 		dev_err(dev, "Can't set SPDIF clock rate: %d\n", ret);
172 		return ret;
173 	}
174 
175 	return 0;
176 }
177 
tegra_spdif_start_playback(struct tegra_spdif * spdif)178 static void tegra_spdif_start_playback(struct tegra_spdif *spdif)
179 {
180 	spdif->reg_ctrl |= TEGRA_SPDIF_CTRL_TX_EN;
181 	tegra_spdif_write(spdif, TEGRA_SPDIF_CTRL, spdif->reg_ctrl);
182 }
183 
tegra_spdif_stop_playback(struct tegra_spdif * spdif)184 static void tegra_spdif_stop_playback(struct tegra_spdif *spdif)
185 {
186 	spdif->reg_ctrl &= ~TEGRA_SPDIF_CTRL_TX_EN;
187 	tegra_spdif_write(spdif, TEGRA_SPDIF_CTRL, spdif->reg_ctrl);
188 }
189 
tegra_spdif_trigger(struct snd_pcm_substream * substream,int cmd,struct snd_soc_dai * dai)190 static int tegra_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
191 				struct snd_soc_dai *dai)
192 {
193 	struct tegra_spdif *spdif = snd_soc_dai_get_drvdata(dai);
194 
195 	switch (cmd) {
196 	case SNDRV_PCM_TRIGGER_START:
197 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
198 	case SNDRV_PCM_TRIGGER_RESUME:
199 		if (!spdif->clk_refs)
200 			clk_enable(spdif->clk_spdif_out);
201 		spdif->clk_refs++;
202 		tegra_spdif_start_playback(spdif);
203 		break;
204 	case SNDRV_PCM_TRIGGER_STOP:
205 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
206 	case SNDRV_PCM_TRIGGER_SUSPEND:
207 		tegra_spdif_stop_playback(spdif);
208 		spdif->clk_refs--;
209 		if (!spdif->clk_refs)
210 			clk_disable(spdif->clk_spdif_out);
211 		break;
212 	default:
213 		return -EINVAL;
214 	}
215 
216 	return 0;
217 }
218 
tegra_spdif_probe(struct snd_soc_dai * dai)219 static int tegra_spdif_probe(struct snd_soc_dai *dai)
220 {
221 	struct tegra_spdif *spdif = snd_soc_dai_get_drvdata(dai);
222 
223 	dai->capture_dma_data = NULL;
224 	dai->playback_dma_data = &spdif->playback_dma_data;
225 
226 	return 0;
227 }
228 
229 static const struct snd_soc_dai_ops tegra_spdif_dai_ops = {
230 	.hw_params	= tegra_spdif_hw_params,
231 	.trigger	= tegra_spdif_trigger,
232 };
233 
234 static struct snd_soc_dai_driver tegra_spdif_dai = {
235 	.name = DRV_NAME,
236 	.probe = tegra_spdif_probe,
237 	.playback = {
238 		.channels_min = 2,
239 		.channels_max = 2,
240 		.rates = SNDRV_PCM_RATE_32000 | SNDRV_PCM_RATE_44100 |
241 				SNDRV_PCM_RATE_48000,
242 		.formats = SNDRV_PCM_FMTBIT_S16_LE,
243 	},
244 	.ops = &tegra_spdif_dai_ops,
245 };
246 
tegra_spdif_platform_probe(struct platform_device * pdev)247 static __devinit int tegra_spdif_platform_probe(struct platform_device *pdev)
248 {
249 	struct tegra_spdif *spdif;
250 	struct resource *mem, *memregion, *dmareq;
251 	int ret;
252 
253 	spdif = kzalloc(sizeof(struct tegra_spdif), GFP_KERNEL);
254 	if (!spdif) {
255 		dev_err(&pdev->dev, "Can't allocate tegra_spdif\n");
256 		ret = -ENOMEM;
257 		goto exit;
258 	}
259 	dev_set_drvdata(&pdev->dev, spdif);
260 
261 	spdif->clk_spdif_out = clk_get(&pdev->dev, "spdif_out");
262 	if (IS_ERR(spdif->clk_spdif_out)) {
263 		pr_err("Can't retrieve spdif clock\n");
264 		ret = PTR_ERR(spdif->clk_spdif_out);
265 		goto err_free;
266 	}
267 
268 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
269 	if (!mem) {
270 		dev_err(&pdev->dev, "No memory resource\n");
271 		ret = -ENODEV;
272 		goto err_clk_put;
273 	}
274 
275 	dmareq = platform_get_resource(pdev, IORESOURCE_DMA, 0);
276 	if (!dmareq) {
277 		dev_err(&pdev->dev, "No DMA resource\n");
278 		ret = -ENODEV;
279 		goto err_clk_put;
280 	}
281 
282 	memregion = request_mem_region(mem->start, resource_size(mem),
283 					DRV_NAME);
284 	if (!memregion) {
285 		dev_err(&pdev->dev, "Memory region already claimed\n");
286 		ret = -EBUSY;
287 		goto err_clk_put;
288 	}
289 
290 	spdif->regs = ioremap(mem->start, resource_size(mem));
291 	if (!spdif->regs) {
292 		dev_err(&pdev->dev, "ioremap failed\n");
293 		ret = -ENOMEM;
294 		goto err_release;
295 	}
296 
297 	spdif->playback_dma_data.addr = mem->start + TEGRA_SPDIF_DATA_OUT;
298 	spdif->playback_dma_data.wrap = 4;
299 	spdif->playback_dma_data.width = 32;
300 	spdif->playback_dma_data.req_sel = dmareq->start;
301 
302 	ret = snd_soc_register_dai(&pdev->dev, &tegra_spdif_dai);
303 	if (ret) {
304 		dev_err(&pdev->dev, "Could not register DAI: %d\n", ret);
305 		ret = -ENOMEM;
306 		goto err_unmap;
307 	}
308 
309 	tegra_spdif_debug_add(spdif);
310 
311 	return 0;
312 
313 err_unmap:
314 	iounmap(spdif->regs);
315 err_release:
316 	release_mem_region(mem->start, resource_size(mem));
317 err_clk_put:
318 	clk_put(spdif->clk_spdif_out);
319 err_free:
320 	kfree(spdif);
321 exit:
322 	return ret;
323 }
324 
tegra_spdif_platform_remove(struct platform_device * pdev)325 static int __devexit tegra_spdif_platform_remove(struct platform_device *pdev)
326 {
327 	struct tegra_spdif *spdif = dev_get_drvdata(&pdev->dev);
328 	struct resource *res;
329 
330 	snd_soc_unregister_dai(&pdev->dev);
331 
332 	tegra_spdif_debug_remove(spdif);
333 
334 	iounmap(spdif->regs);
335 
336 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
337 	release_mem_region(res->start, resource_size(res));
338 
339 	clk_put(spdif->clk_spdif_out);
340 
341 	kfree(spdif);
342 
343 	return 0;
344 }
345 
346 static struct platform_driver tegra_spdif_driver = {
347 	.driver = {
348 		.name = DRV_NAME,
349 		.owner = THIS_MODULE,
350 	},
351 	.probe = tegra_spdif_platform_probe,
352 	.remove = __devexit_p(tegra_spdif_platform_remove),
353 };
354 
355 module_platform_driver(tegra_spdif_driver);
356 
357 MODULE_AUTHOR("Stephen Warren <swarren@nvidia.com>");
358 MODULE_DESCRIPTION("Tegra SPDIF ASoC driver");
359 MODULE_LICENSE("GPL");
360 MODULE_ALIAS("platform:" DRV_NAME);
361