free electrons

Embedded Linux Experts

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
/* sound/soc/samsung/spdif.c
 *
 * ALSA SoC Audio Layer - Samsung S/PDIF Controller driver
 *
 * Copyright (c) 2010 Samsung Electronics Co. Ltd
 *		http://www.samsung.com/
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/clk.h>
#include <linux/io.h>
#include <linux/module.h>

#include <sound/soc.h>
#include <sound/pcm_params.h>

#include <linux/platform_data/asoc-s3c.h>

#include "dma.h"
#include "spdif.h"

/* Registers */
#define CLKCON				0x00
#define CON				0x04
#define BSTAS				0x08
#define CSTAS				0x0C
#define DATA_OUTBUF			0x10
#define DCNT				0x14
#define BSTAS_S				0x18
#define DCNT_S				0x1C

#define CLKCTL_MASK			0x7
#define CLKCTL_MCLK_EXT			(0x1 << 2)
#define CLKCTL_PWR_ON			(0x1 << 0)

#define CON_MASK			0x3ffffff
#define CON_FIFO_TH_SHIFT		19
#define CON_FIFO_TH_MASK		(0x7 << 19)
#define CON_USERDATA_23RDBIT		(0x1 << 12)

#define CON_SW_RESET			(0x1 << 5)

#define CON_MCLKDIV_MASK		(0x3 << 3)
#define CON_MCLKDIV_256FS		(0x0 << 3)
#define CON_MCLKDIV_384FS		(0x1 << 3)
#define CON_MCLKDIV_512FS		(0x2 << 3)

#define CON_PCM_MASK			(0x3 << 1)
#define CON_PCM_16BIT			(0x0 << 1)
#define CON_PCM_20BIT			(0x1 << 1)
#define CON_PCM_24BIT			(0x2 << 1)

#define CON_PCM_DATA			(0x1 << 0)

#define CSTAS_MASK			0x3fffffff
#define CSTAS_SAMP_FREQ_MASK		(0xF << 24)
#define CSTAS_SAMP_FREQ_44		(0x0 << 24)
#define CSTAS_SAMP_FREQ_48		(0x2 << 24)
#define CSTAS_SAMP_FREQ_32		(0x3 << 24)
#define CSTAS_SAMP_FREQ_96		(0xA << 24)

#define CSTAS_CATEGORY_MASK		(0xFF << 8)
#define CSTAS_CATEGORY_CODE_CDP		(0x01 << 8)

#define CSTAS_NO_COPYRIGHT		(0x1 << 2)

/**
 * struct samsung_spdif_info - Samsung S/PDIF Controller information
 * @lock: Spin lock for S/PDIF.
 * @dev: The parent device passed to use from the probe.
 * @regs: The pointer to the device register block.
 * @clk_rate: Current clock rate for calcurate ratio.
 * @pclk: The peri-clock pointer for spdif master operation.
 * @sclk: The source clock pointer for making sync signals.
 * @save_clkcon: Backup clkcon reg. in suspend.
 * @save_con: Backup con reg. in suspend.
 * @save_cstas: Backup cstas reg. in suspend.
 * @dma_playback: DMA information for playback channel.
 */
struct samsung_spdif_info {
	spinlock_t	lock;
	struct device	*dev;
	void __iomem	*regs;
	unsigned long	clk_rate;
	struct clk	*pclk;
	struct clk	*sclk;
	u32		saved_clkcon;
	u32		saved_con;
	u32		saved_cstas;
	struct snd_dmaengine_dai_dma_data *dma_playback;
};

static struct snd_dmaengine_dai_dma_data spdif_stereo_out;
static struct samsung_spdif_info spdif_info;

static inline struct samsung_spdif_info *to_info(struct snd_soc_dai *cpu_dai)
{
	return snd_soc_dai_get_drvdata(cpu_dai);
}

static void spdif_snd_txctrl(struct samsung_spdif_info *spdif, int on)
{
	void __iomem *regs = spdif->regs;
	u32 clkcon;

	dev_dbg(spdif->dev, "Entered %s\n", __func__);

	clkcon = readl(regs + CLKCON) & CLKCTL_MASK;
	if (on)
		writel(clkcon | CLKCTL_PWR_ON, regs + CLKCON);
	else
		writel(clkcon & ~CLKCTL_PWR_ON, regs + CLKCON);
}

static int spdif_set_sysclk(struct snd_soc_dai *cpu_dai,
				int clk_id, unsigned int freq, int dir)
{
	struct samsung_spdif_info *spdif = to_info(cpu_dai);
	u32 clkcon;

	dev_dbg(spdif->dev, "Entered %s\n", __func__);

	clkcon = readl(spdif->regs + CLKCON);

	if (clk_id == SND_SOC_SPDIF_INT_MCLK)
		clkcon &= ~CLKCTL_MCLK_EXT;
	else
		clkcon |= CLKCTL_MCLK_EXT;

	writel(clkcon, spdif->regs + CLKCON);

	spdif->clk_rate = freq;

	return 0;
}

static int spdif_trigger(struct snd_pcm_substream *substream, int cmd,
				struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct samsung_spdif_info *spdif = to_info(rtd->cpu_dai);
	unsigned long flags;

	dev_dbg(spdif->dev, "Entered %s\n", __func__);

	switch (cmd) {
	case SNDRV_PCM_TRIGGER_START:
	case SNDRV_PCM_TRIGGER_RESUME:
	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
		spin_lock_irqsave(&spdif->lock, flags);
		spdif_snd_txctrl(spdif, 1);
		spin_unlock_irqrestore(&spdif->lock, flags);
		break;
	case SNDRV_PCM_TRIGGER_STOP:
	case SNDRV_PCM_TRIGGER_SUSPEND:
	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
		spin_lock_irqsave(&spdif->lock, flags);
		spdif_snd_txctrl(spdif, 0);
		spin_unlock_irqrestore(&spdif->lock, flags);
		break;
	default:
		return -EINVAL;
	}

	return 0;
}

static int spdif_sysclk_ratios[] = {
	512, 384, 256,
};

static int spdif_hw_params(struct snd_pcm_substream *substream,
				struct snd_pcm_hw_params *params,
				struct snd_soc_dai *socdai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct samsung_spdif_info *spdif = to_info(rtd->cpu_dai);
	void __iomem *regs = spdif->regs;
	struct snd_dmaengine_dai_dma_data *dma_data;
	u32 con, clkcon, cstas;
	unsigned long flags;
	int i, ratio;

	dev_dbg(spdif->dev, "Entered %s\n", __func__);

	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
		dma_data = spdif->dma_playback;
	else {
		dev_err(spdif->dev, "Capture is not supported\n");
		return -EINVAL;
	}

	snd_soc_dai_set_dma_data(rtd->cpu_dai, substream, dma_data);

	spin_lock_irqsave(&spdif->lock, flags);

	con = readl(regs + CON) & CON_MASK;
	cstas = readl(regs + CSTAS) & CSTAS_MASK;
	clkcon = readl(regs + CLKCON) & CLKCTL_MASK;

	con &= ~CON_FIFO_TH_MASK;
	con |= (0x7 << CON_FIFO_TH_SHIFT);
	con |= CON_USERDATA_23RDBIT;
	con |= CON_PCM_DATA;

	con &= ~CON_PCM_MASK;
	switch (params_width(params)) {
	case 16:
		con |= CON_PCM_16BIT;
		break;
	default:
		dev_err(spdif->dev, "Unsupported data size.\n");
		goto err;
	}

	ratio = spdif->clk_rate / params_rate(params);
	for (i = 0; i < ARRAY_SIZE(spdif_sysclk_ratios); i++)
		if (ratio == spdif_sysclk_ratios[i])
			break;
	if (i == ARRAY_SIZE(spdif_sysclk_ratios)) {
		dev_err(spdif->dev, "Invalid clock ratio %ld/%d\n",
				spdif->clk_rate, params_rate(params));
		goto err;
	}

	con &= ~CON_MCLKDIV_MASK;
	switch (ratio) {
	case 256:
		con |= CON_MCLKDIV_256FS;
		break;
	case 384:
		con |= CON_MCLKDIV_384FS;
		break;
	case 512:
		con |= CON_MCLKDIV_512FS;
		break;
	}

	cstas &= ~CSTAS_SAMP_FREQ_MASK;
	switch (params_rate(params)) {
	case 44100:
		cstas |= CSTAS_SAMP_FREQ_44;
		break;
	case 48000:
		cstas |= CSTAS_SAMP_FREQ_48;
		break;
	case 32000:
		cstas |= CSTAS_SAMP_FREQ_32;
		break;
	case 96000:
		cstas |= CSTAS_SAMP_FREQ_96;
		break;
	default:
		dev_err(spdif->dev, "Invalid sampling rate %d\n",
				params_rate(params));
		goto err;
	}

	cstas &= ~CSTAS_CATEGORY_MASK;
	cstas |= CSTAS_CATEGORY_CODE_CDP;
	cstas |= CSTAS_NO_COPYRIGHT;

	writel(con, regs + CON);
	writel(cstas, regs + CSTAS);
	writel(clkcon, regs + CLKCON);

	spin_unlock_irqrestore(&spdif->lock, flags);

	return 0;
err:
	spin_unlock_irqrestore(&spdif->lock, flags);
	return -EINVAL;
}

static void spdif_shutdown(struct snd_pcm_substream *substream,
				struct snd_soc_dai *dai)
{
	struct snd_soc_pcm_runtime *rtd = substream->private_data;
	struct samsung_spdif_info *spdif = to_info(rtd->cpu_dai);
	void __iomem *regs = spdif->regs;
	u32 con, clkcon;

	dev_dbg(spdif->dev, "Entered %s\n", __func__);

	con = readl(regs + CON) & CON_MASK;
	clkcon = readl(regs + CLKCON) & CLKCTL_MASK;

	writel(con | CON_SW_RESET, regs + CON);
	cpu_relax();

	writel(clkcon & ~CLKCTL_PWR_ON, regs + CLKCON);
}

#ifdef CONFIG_PM
static int spdif_suspend(struct snd_soc_dai *cpu_dai)
{
	struct samsung_spdif_info *spdif = to_info(cpu_dai);
	u32 con = spdif->saved_con;

	dev_dbg(spdif->dev, "Entered %s\n", __func__);

	spdif->saved_clkcon = readl(spdif->regs	+ CLKCON) & CLKCTL_MASK;
	spdif->saved_con = readl(spdif->regs + CON) & CON_MASK;
	spdif->saved_cstas = readl(spdif->regs + CSTAS) & CSTAS_MASK;

	writel(con | CON_SW_RESET, spdif->regs + CON);
	cpu_relax();

	return 0;
}

static int spdif_resume(struct snd_soc_dai *cpu_dai)
{
	struct samsung_spdif_info *spdif = to_info(cpu_dai);

	dev_dbg(spdif->dev, "Entered %s\n", __func__);

	writel(spdif->saved_clkcon, spdif->regs	+ CLKCON);
	writel(spdif->saved_con, spdif->regs + CON);
	writel(spdif->saved_cstas, spdif->regs + CSTAS);

	return 0;
}
#else
#define spdif_suspend NULL
#define spdif_resume NULL
#endif

static const struct snd_soc_dai_ops spdif_dai_ops = {
	.set_sysclk	= spdif_set_sysclk,
	.trigger	= spdif_trigger,
	.hw_params	= spdif_hw_params,
	.shutdown	= spdif_shutdown,
};

static struct snd_soc_dai_driver samsung_spdif_dai = {
	.name = "samsung-spdif",
	.playback = {
		.stream_name = "S/PDIF Playback",
		.channels_min = 2,
		.channels_max = 2,
		.rates = (SNDRV_PCM_RATE_32000 |
				SNDRV_PCM_RATE_44100 |
				SNDRV_PCM_RATE_48000 |
				SNDRV_PCM_RATE_96000),
		.formats = SNDRV_PCM_FMTBIT_S16_LE, },
	.ops = &spdif_dai_ops,
	.suspend = spdif_suspend,
	.resume = spdif_resume,
};

static const struct snd_soc_component_driver samsung_spdif_component = {
	.name		= "samsung-spdif",
};

static int spdif_probe(struct platform_device *pdev)
{
	struct s3c_audio_pdata *spdif_pdata;
	struct resource *mem_res;
	struct samsung_spdif_info *spdif;
	dma_filter_fn filter;
	int ret;

	spdif_pdata = pdev->dev.platform_data;

	dev_dbg(&pdev->dev, "Entered %s\n", __func__);

	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (!mem_res) {
		dev_err(&pdev->dev, "Unable to get register resource.\n");
		return -ENXIO;
	}

	if (spdif_pdata && spdif_pdata->cfg_gpio
			&& spdif_pdata->cfg_gpio(pdev)) {
		dev_err(&pdev->dev, "Unable to configure GPIO pins\n");
		return -EINVAL;
	}

	spdif = &spdif_info;
	spdif->dev = &pdev->dev;

	spin_lock_init(&spdif->lock);

	spdif->pclk = devm_clk_get(&pdev->dev, "spdif");
	if (IS_ERR(spdif->pclk)) {
		dev_err(&pdev->dev, "failed to get peri-clock\n");
		ret = -ENOENT;
		goto err0;
	}
	clk_prepare_enable(spdif->pclk);

	spdif->sclk = devm_clk_get(&pdev->dev, "sclk_spdif");
	if (IS_ERR(spdif->sclk)) {
		dev_err(&pdev->dev, "failed to get internal source clock\n");
		ret = -ENOENT;
		goto err1;
	}
	clk_prepare_enable(spdif->sclk);

	/* Request S/PDIF Register's memory region */
	if (!request_mem_region(mem_res->start,
				resource_size(mem_res), "samsung-spdif")) {
		dev_err(&pdev->dev, "Unable to request register region\n");
		ret = -EBUSY;
		goto err2;
	}

	spdif->regs = ioremap(mem_res->start, 0x100);
	if (spdif->regs == NULL) {
		dev_err(&pdev->dev, "Cannot ioremap registers\n");
		ret = -ENXIO;
		goto err3;
	}

	spdif_stereo_out.addr_width = 2;
	spdif_stereo_out.addr = mem_res->start + DATA_OUTBUF;
	filter = NULL;
	if (spdif_pdata) {
		spdif_stereo_out.filter_data = spdif_pdata->dma_playback;
		filter = spdif_pdata->dma_filter;
	}
	spdif->dma_playback = &spdif_stereo_out;

	ret = samsung_asoc_dma_platform_register(&pdev->dev, filter,
						 NULL, NULL);
	if (ret) {
		dev_err(&pdev->dev, "failed to register DMA: %d\n", ret);
		goto err4;
	}

	dev_set_drvdata(&pdev->dev, spdif);

	ret = devm_snd_soc_register_component(&pdev->dev,
			&samsung_spdif_component, &samsung_spdif_dai, 1);
	if (ret != 0) {
		dev_err(&pdev->dev, "fail to register dai\n");
		goto err4;
	}

	return 0;
err4:
	iounmap(spdif->regs);
err3:
	release_mem_region(mem_res->start, resource_size(mem_res));
err2:
	clk_disable_unprepare(spdif->sclk);
err1:
	clk_disable_unprepare(spdif->pclk);
err0:
	return ret;
}

static int spdif_remove(struct platform_device *pdev)
{
	struct samsung_spdif_info *spdif = &spdif_info;
	struct resource *mem_res;

	iounmap(spdif->regs);

	mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	if (mem_res)
		release_mem_region(mem_res->start, resource_size(mem_res));

	clk_disable_unprepare(spdif->sclk);
	clk_disable_unprepare(spdif->pclk);

	return 0;
}

static struct platform_driver samsung_spdif_driver = {
	.probe	= spdif_probe,
	.remove	= spdif_remove,
	.driver	= {
		.name	= "samsung-spdif",
	},
};

module_platform_driver(samsung_spdif_driver);

MODULE_AUTHOR("Seungwhan Youn, <sw.youn@samsung.com>");
MODULE_DESCRIPTION("Samsung S/PDIF Controller Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:samsung-spdif");