xref: /openbmc/linux/sound/soc/atmel/atmel-i2s.c (revision b543e467)
1 /*
2  * Driver for Atmel I2S controller
3  *
4  * Copyright (C) 2015 Atmel Corporation
5  *
6  * Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License version 2 as published by
10  * the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but WITHOUT
13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
15  * more details.
16  *
17  * You should have received a copy of the GNU General Public License along with
18  * this program.  If not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/device.h>
24 #include <linux/slab.h>
25 #include <linux/delay.h>
26 #include <linux/io.h>
27 #include <linux/clk.h>
28 #include <linux/mfd/syscon.h>
29 
30 #include <sound/core.h>
31 #include <sound/pcm.h>
32 #include <sound/pcm_params.h>
33 #include <sound/initval.h>
34 #include <sound/soc.h>
35 #include <sound/dmaengine_pcm.h>
36 
37 #define ATMEL_I2SC_MAX_TDM_CHANNELS	8
38 
39 /*
40  * ---- I2S Controller Register map ----
41  */
42 #define ATMEL_I2SC_CR		0x0000	/* Control Register */
43 #define ATMEL_I2SC_MR		0x0004	/* Mode Register */
44 #define ATMEL_I2SC_SR		0x0008	/* Status Register */
45 #define ATMEL_I2SC_SCR		0x000c	/* Status Clear Register */
46 #define ATMEL_I2SC_SSR		0x0010	/* Status Set Register */
47 #define ATMEL_I2SC_IER		0x0014	/* Interrupt Enable Register */
48 #define ATMEL_I2SC_IDR		0x0018	/* Interrupt Disable Register */
49 #define ATMEL_I2SC_IMR		0x001c	/* Interrupt Mask Register */
50 #define ATMEL_I2SC_RHR		0x0020	/* Receiver Holding Register */
51 #define ATMEL_I2SC_THR		0x0024	/* Transmitter Holding Register */
52 #define ATMEL_I2SC_VERSION	0x0028	/* Version Register */
53 
54 /*
55  * ---- Control Register (Write-only) ----
56  */
57 #define ATMEL_I2SC_CR_RXEN	BIT(0)	/* Receiver Enable */
58 #define ATMEL_I2SC_CR_RXDIS	BIT(1)	/* Receiver Disable */
59 #define ATMEL_I2SC_CR_CKEN	BIT(2)	/* Clock Enable */
60 #define ATMEL_I2SC_CR_CKDIS	BIT(3)	/* Clock Disable */
61 #define ATMEL_I2SC_CR_TXEN	BIT(4)	/* Transmitter Enable */
62 #define ATMEL_I2SC_CR_TXDIS	BIT(5)	/* Transmitter Disable */
63 #define ATMEL_I2SC_CR_SWRST	BIT(7)	/* Software Reset */
64 
65 /*
66  * ---- Mode Register (Read/Write) ----
67  */
68 #define ATMEL_I2SC_MR_MODE_MASK		GENMASK(0, 0)
69 #define ATMEL_I2SC_MR_MODE_SLAVE	(0 << 0)
70 #define ATMEL_I2SC_MR_MODE_MASTER	(1 << 0)
71 
72 #define ATMEL_I2SC_MR_DATALENGTH_MASK		GENMASK(4, 2)
73 #define ATMEL_I2SC_MR_DATALENGTH_32_BITS	(0 << 2)
74 #define ATMEL_I2SC_MR_DATALENGTH_24_BITS	(1 << 2)
75 #define ATMEL_I2SC_MR_DATALENGTH_20_BITS	(2 << 2)
76 #define ATMEL_I2SC_MR_DATALENGTH_18_BITS	(3 << 2)
77 #define ATMEL_I2SC_MR_DATALENGTH_16_BITS	(4 << 2)
78 #define ATMEL_I2SC_MR_DATALENGTH_16_BITS_COMPACT	(5 << 2)
79 #define ATMEL_I2SC_MR_DATALENGTH_8_BITS		(6 << 2)
80 #define ATMEL_I2SC_MR_DATALENGTH_8_BITS_COMPACT	(7 << 2)
81 
82 #define ATMEL_I2SC_MR_FORMAT_MASK	GENMASK(7, 6)
83 #define ATMEL_I2SC_MR_FORMAT_I2S	(0 << 6)
84 #define ATMEL_I2SC_MR_FORMAT_LJ		(1 << 6)  /* Left Justified */
85 #define ATMEL_I2SC_MR_FORMAT_TDM	(2 << 6)
86 #define ATMEL_I2SC_MR_FORMAT_TDMLJ	(3 << 6)
87 
88 /* Left audio samples duplicated to right audio channel */
89 #define ATMEL_I2SC_MR_RXMONO		BIT(8)
90 
91 /* Receiver uses one DMA channel ... */
92 #define ATMEL_I2SC_MR_RXDMA_MASK	GENMASK(9, 9)
93 #define ATMEL_I2SC_MR_RXDMA_SINGLE	(0 << 9)  /* for all audio channels */
94 #define ATMEL_I2SC_MR_RXDMA_MULTIPLE	(1 << 9)  /* per audio channel */
95 
96 /* I2SDO output of I2SC is internally connected to I2SDI input */
97 #define ATMEL_I2SC_MR_RXLOOP		BIT(10)
98 
99 /* Left audio samples duplicated to right audio channel */
100 #define ATMEL_I2SC_MR_TXMONO		BIT(12)
101 
102 /* Transmitter uses one DMA channel ... */
103 #define ATMEL_I2SC_MR_TXDMA_MASK	GENMASK(13, 13)
104 #define ATMEL_I2SC_MR_TXDMA_SINGLE	(0 << 13)  /* for all audio channels */
105 #define ATMEL_I2SC_MR_TXDME_MULTIPLE	(1 << 13)  /* per audio channel */
106 
107 /* x sample transmitted when underrun */
108 #define ATMEL_I2SC_MR_TXSAME_MASK	GENMASK(14, 14)
109 #define ATMEL_I2SC_MR_TXSAME_ZERO	(0 << 14)  /* Zero sample */
110 #define ATMEL_I2SC_MR_TXSAME_PREVIOUS	(1 << 14)  /* Previous sample */
111 
112 /* Audio Clock to I2SC Master Clock ratio */
113 #define ATMEL_I2SC_MR_IMCKDIV_MASK	GENMASK(21, 16)
114 #define ATMEL_I2SC_MR_IMCKDIV(div) \
115 	(((div) << 16) & ATMEL_I2SC_MR_IMCKDIV_MASK)
116 
117 /* Master Clock to fs ratio */
118 #define ATMEL_I2SC_MR_IMCKFS_MASK	GENMASK(29, 24)
119 #define ATMEL_I2SC_MR_IMCKFS(fs) \
120 	(((fs) << 24) & ATMEL_I2SC_MR_IMCKFS_MASK)
121 
122 /* Master Clock mode */
123 #define ATMEL_I2SC_MR_IMCKMODE_MASK	GENMASK(30, 30)
124 /* 0: No master clock generated (selected clock drives I2SCK pin) */
125 #define ATMEL_I2SC_MR_IMCKMODE_I2SCK	(0 << 30)
126 /* 1: master clock generated (internally generated clock drives I2SMCK pin) */
127 #define ATMEL_I2SC_MR_IMCKMODE_I2SMCK	(1 << 30)
128 
129 /* Slot Width */
130 /* 0: slot is 32 bits wide for DATALENGTH = 18/20/24 bits. */
131 /* 1: slot is 24 bits wide for DATALENGTH = 18/20/24 bits. */
132 #define ATMEL_I2SC_MR_IWS		BIT(31)
133 
134 /*
135  * ---- Status Registers ----
136  */
137 #define ATMEL_I2SC_SR_RXEN	BIT(0)	/* Receiver Enabled */
138 #define ATMEL_I2SC_SR_RXRDY	BIT(1)	/* Receive Ready */
139 #define ATMEL_I2SC_SR_RXOR	BIT(2)	/* Receive Overrun */
140 
141 #define ATMEL_I2SC_SR_TXEN	BIT(4)	/* Transmitter Enabled */
142 #define ATMEL_I2SC_SR_TXRDY	BIT(5)	/* Transmit Ready */
143 #define ATMEL_I2SC_SR_TXUR	BIT(6)	/* Transmit Underrun */
144 
145 /* Receive Overrun Channel */
146 #define ATMEL_I2SC_SR_RXORCH_MASK	GENMASK(15, 8)
147 #define ATMEL_I2SC_SR_RXORCH(ch)	(1 << (((ch) & 0x7) + 8))
148 
149 /* Transmit Underrun Channel */
150 #define ATMEL_I2SC_SR_TXURCH_MASK	GENMASK(27, 20)
151 #define ATMEL_I2SC_SR_TXURCH(ch)	(1 << (((ch) & 0x7) + 20))
152 
153 /*
154  * ---- Interrupt Enable/Disable/Mask Registers ----
155  */
156 #define ATMEL_I2SC_INT_RXRDY	ATMEL_I2SC_SR_RXRDY
157 #define ATMEL_I2SC_INT_RXOR	ATMEL_I2SC_SR_RXOR
158 #define ATMEL_I2SC_INT_TXRDY	ATMEL_I2SC_SR_TXRDY
159 #define ATMEL_I2SC_INT_TXUR	ATMEL_I2SC_SR_TXUR
160 
161 static const struct regmap_config atmel_i2s_regmap_config = {
162 	.reg_bits = 32,
163 	.reg_stride = 4,
164 	.val_bits = 32,
165 	.max_register = ATMEL_I2SC_VERSION,
166 };
167 
168 struct atmel_i2s_gck_param {
169 	int		fs;
170 	unsigned long	mck;
171 	int		imckdiv;
172 	int		imckfs;
173 };
174 
175 #define I2S_MCK_12M288		12288000UL
176 #define I2S_MCK_11M2896		11289600UL
177 
178 /* mck = (32 * (imckfs+1) / (imckdiv+1)) * fs */
179 static const struct atmel_i2s_gck_param gck_params[] = {
180 	/* mck = 12.288MHz */
181 	{  8000, I2S_MCK_12M288, 0, 47},	/* mck = 1536 fs */
182 	{ 16000, I2S_MCK_12M288, 1, 47},	/* mck =  768 fs */
183 	{ 24000, I2S_MCK_12M288, 3, 63},	/* mck =  512 fs */
184 	{ 32000, I2S_MCK_12M288, 3, 47},	/* mck =  384 fs */
185 	{ 48000, I2S_MCK_12M288, 7, 63},	/* mck =  256 fs */
186 	{ 64000, I2S_MCK_12M288, 7, 47},	/* mck =  192 fs */
187 	{ 96000, I2S_MCK_12M288, 7, 31},	/* mck =  128 fs */
188 	{192000, I2S_MCK_12M288, 7, 15},	/* mck =   64 fs */
189 
190 	/* mck = 11.2896MHz */
191 	{ 11025, I2S_MCK_11M2896, 1, 63},	/* mck = 1024 fs */
192 	{ 22050, I2S_MCK_11M2896, 3, 63},	/* mck =  512 fs */
193 	{ 44100, I2S_MCK_11M2896, 7, 63},	/* mck =  256 fs */
194 	{ 88200, I2S_MCK_11M2896, 7, 31},	/* mck =  128 fs */
195 	{176400, I2S_MCK_11M2896, 7, 15},	/* mck =   64 fs */
196 };
197 
198 struct atmel_i2s_dev;
199 
200 struct atmel_i2s_caps {
201 	int	(*mck_init)(struct atmel_i2s_dev *, struct device_node *np);
202 };
203 
204 struct atmel_i2s_dev {
205 	struct device				*dev;
206 	struct regmap				*regmap;
207 	struct clk				*pclk;
208 	struct clk				*gclk;
209 	struct clk				*aclk;
210 	struct snd_dmaengine_dai_dma_data	playback;
211 	struct snd_dmaengine_dai_dma_data	capture;
212 	unsigned int				fmt;
213 	const struct atmel_i2s_gck_param	*gck_param;
214 	const struct atmel_i2s_caps		*caps;
215 };
216 
217 static irqreturn_t atmel_i2s_interrupt(int irq, void *dev_id)
218 {
219 	struct atmel_i2s_dev *dev = dev_id;
220 	unsigned int sr, imr, pending, ch, mask;
221 	irqreturn_t ret = IRQ_NONE;
222 
223 	regmap_read(dev->regmap, ATMEL_I2SC_SR, &sr);
224 	regmap_read(dev->regmap, ATMEL_I2SC_IMR, &imr);
225 	pending = sr & imr;
226 
227 	if (!pending)
228 		return IRQ_NONE;
229 
230 	if (pending & ATMEL_I2SC_INT_RXOR) {
231 		mask = ATMEL_I2SC_SR_RXOR;
232 
233 		for (ch = 0; ch < ATMEL_I2SC_MAX_TDM_CHANNELS; ++ch) {
234 			if (sr & ATMEL_I2SC_SR_RXORCH(ch)) {
235 				mask |= ATMEL_I2SC_SR_RXORCH(ch);
236 				dev_err(dev->dev,
237 					"RX overrun on channel %d\n", ch);
238 			}
239 		}
240 		regmap_write(dev->regmap, ATMEL_I2SC_SCR, mask);
241 		ret = IRQ_HANDLED;
242 	}
243 
244 	if (pending & ATMEL_I2SC_INT_TXUR) {
245 		mask = ATMEL_I2SC_SR_TXUR;
246 
247 		for (ch = 0; ch < ATMEL_I2SC_MAX_TDM_CHANNELS; ++ch) {
248 			if (sr & ATMEL_I2SC_SR_TXURCH(ch)) {
249 				mask |= ATMEL_I2SC_SR_TXURCH(ch);
250 				dev_err(dev->dev,
251 					"TX underrun on channel %d\n", ch);
252 			}
253 		}
254 		regmap_write(dev->regmap, ATMEL_I2SC_SCR, mask);
255 		ret = IRQ_HANDLED;
256 	}
257 
258 	return ret;
259 }
260 
261 #define ATMEL_I2S_RATES		SNDRV_PCM_RATE_8000_192000
262 
263 #define ATMEL_I2S_FORMATS	(SNDRV_PCM_FMTBIT_S8 |		\
264 				 SNDRV_PCM_FMTBIT_S16_LE |	\
265 				 SNDRV_PCM_FMTBIT_S18_3LE |	\
266 				 SNDRV_PCM_FMTBIT_S20_3LE |	\
267 				 SNDRV_PCM_FMTBIT_S24_3LE |	\
268 				 SNDRV_PCM_FMTBIT_S24_LE |	\
269 				 SNDRV_PCM_FMTBIT_S32_LE)
270 
271 static int atmel_i2s_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
272 {
273 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
274 
275 	dev->fmt = fmt;
276 	return 0;
277 }
278 
279 static int atmel_i2s_prepare(struct snd_pcm_substream *substream,
280 			     struct snd_soc_dai *dai)
281 {
282 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
283 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
284 	unsigned int rhr, sr = 0;
285 
286 	if (is_playback) {
287 		regmap_read(dev->regmap, ATMEL_I2SC_SR, &sr);
288 		if (sr & ATMEL_I2SC_SR_RXRDY) {
289 			/*
290 			 * The RX Ready flag should not be set. However if here,
291 			 * we flush (read) the Receive Holding Register to start
292 			 * from a clean state.
293 			 */
294 			dev_dbg(dev->dev, "RXRDY is set\n");
295 			regmap_read(dev->regmap, ATMEL_I2SC_RHR, &rhr);
296 		}
297 	}
298 
299 	return 0;
300 }
301 
302 static int atmel_i2s_get_gck_param(struct atmel_i2s_dev *dev, int fs)
303 {
304 	int i, best;
305 
306 	if (!dev->gclk || !dev->aclk) {
307 		dev_err(dev->dev, "cannot generate the I2S Master Clock\n");
308 		return -EINVAL;
309 	}
310 
311 	/*
312 	 * Find the best possible settings to generate the I2S Master Clock
313 	 * from the PLL Audio.
314 	 */
315 	dev->gck_param = NULL;
316 	best = INT_MAX;
317 	for (i = 0; i < ARRAY_SIZE(gck_params); ++i) {
318 		const struct atmel_i2s_gck_param *gck_param = &gck_params[i];
319 		int val = abs(fs - gck_param->fs);
320 
321 		if (val < best) {
322 			best = val;
323 			dev->gck_param = gck_param;
324 		}
325 	}
326 
327 	return 0;
328 }
329 
330 static int atmel_i2s_hw_params(struct snd_pcm_substream *substream,
331 			       struct snd_pcm_hw_params *params,
332 			       struct snd_soc_dai *dai)
333 {
334 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
335 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
336 	unsigned int mr = 0;
337 	int ret;
338 
339 	switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
340 	case SND_SOC_DAIFMT_I2S:
341 		mr |= ATMEL_I2SC_MR_FORMAT_I2S;
342 		break;
343 
344 	default:
345 		dev_err(dev->dev, "unsupported bus format\n");
346 		return -EINVAL;
347 	}
348 
349 	switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
350 	case SND_SOC_DAIFMT_CBS_CFS:
351 		/* codec is slave, so cpu is master */
352 		mr |= ATMEL_I2SC_MR_MODE_MASTER;
353 		ret = atmel_i2s_get_gck_param(dev, params_rate(params));
354 		if (ret)
355 			return ret;
356 		break;
357 
358 	case SND_SOC_DAIFMT_CBM_CFM:
359 		/* codec is master, so cpu is slave */
360 		mr |= ATMEL_I2SC_MR_MODE_SLAVE;
361 		dev->gck_param = NULL;
362 		break;
363 
364 	default:
365 		dev_err(dev->dev, "unsupported master/slave mode\n");
366 		return -EINVAL;
367 	}
368 
369 	switch (params_channels(params)) {
370 	case 1:
371 		if (is_playback)
372 			mr |= ATMEL_I2SC_MR_TXMONO;
373 		else
374 			mr |= ATMEL_I2SC_MR_RXMONO;
375 		break;
376 	case 2:
377 		break;
378 	default:
379 		dev_err(dev->dev, "unsupported number of audio channels\n");
380 		return -EINVAL;
381 	}
382 
383 	switch (params_format(params)) {
384 	case SNDRV_PCM_FORMAT_S8:
385 		mr |= ATMEL_I2SC_MR_DATALENGTH_8_BITS;
386 		break;
387 
388 	case SNDRV_PCM_FORMAT_S16_LE:
389 		mr |= ATMEL_I2SC_MR_DATALENGTH_16_BITS;
390 		break;
391 
392 	case SNDRV_PCM_FORMAT_S18_3LE:
393 		mr |= ATMEL_I2SC_MR_DATALENGTH_18_BITS | ATMEL_I2SC_MR_IWS;
394 		break;
395 
396 	case SNDRV_PCM_FORMAT_S20_3LE:
397 		mr |= ATMEL_I2SC_MR_DATALENGTH_20_BITS | ATMEL_I2SC_MR_IWS;
398 		break;
399 
400 	case SNDRV_PCM_FORMAT_S24_3LE:
401 		mr |= ATMEL_I2SC_MR_DATALENGTH_24_BITS | ATMEL_I2SC_MR_IWS;
402 		break;
403 
404 	case SNDRV_PCM_FORMAT_S24_LE:
405 		mr |= ATMEL_I2SC_MR_DATALENGTH_24_BITS;
406 		break;
407 
408 	case SNDRV_PCM_FORMAT_S32_LE:
409 		mr |= ATMEL_I2SC_MR_DATALENGTH_32_BITS;
410 		break;
411 
412 	default:
413 		dev_err(dev->dev, "unsupported size/endianness for audio samples\n");
414 		return -EINVAL;
415 	}
416 
417 	return regmap_write(dev->regmap, ATMEL_I2SC_MR, mr);
418 }
419 
420 static int atmel_i2s_switch_mck_generator(struct atmel_i2s_dev *dev,
421 					  bool enabled)
422 {
423 	unsigned int mr, mr_mask;
424 	unsigned long aclk_rate;
425 	int ret;
426 
427 	mr = 0;
428 	mr_mask = (ATMEL_I2SC_MR_IMCKDIV_MASK |
429 		   ATMEL_I2SC_MR_IMCKFS_MASK |
430 		   ATMEL_I2SC_MR_IMCKMODE_MASK);
431 
432 	if (!enabled) {
433 		/* Disable the I2S Master Clock generator. */
434 		ret = regmap_write(dev->regmap, ATMEL_I2SC_CR,
435 				   ATMEL_I2SC_CR_CKDIS);
436 		if (ret)
437 			return ret;
438 
439 		/* Reset the I2S Master Clock generator settings. */
440 		ret = regmap_update_bits(dev->regmap, ATMEL_I2SC_MR,
441 					 mr_mask, mr);
442 		if (ret)
443 			return ret;
444 
445 		/* Disable/unprepare the PMC generated clock. */
446 		clk_disable_unprepare(dev->gclk);
447 
448 		/* Disable/unprepare the PLL audio clock. */
449 		clk_disable_unprepare(dev->aclk);
450 		return 0;
451 	}
452 
453 	if (!dev->gck_param)
454 		return -EINVAL;
455 
456 	aclk_rate = dev->gck_param->mck * (dev->gck_param->imckdiv + 1);
457 
458 	/* Fist change the PLL audio clock frequency ... */
459 	ret = clk_set_rate(dev->aclk, aclk_rate);
460 	if (ret)
461 		return ret;
462 
463 	/*
464 	 * ... then set the PMC generated clock rate to the very same frequency
465 	 * to set the gclk parent to aclk.
466 	 */
467 	ret = clk_set_rate(dev->gclk, aclk_rate);
468 	if (ret)
469 		return ret;
470 
471 	/* Prepare and enable the PLL audio clock first ... */
472 	ret = clk_prepare_enable(dev->aclk);
473 	if (ret)
474 		return ret;
475 
476 	/* ... then prepare and enable the PMC generated clock. */
477 	ret = clk_prepare_enable(dev->gclk);
478 	if (ret)
479 		return ret;
480 
481 	/* Update the Mode Register to generate the I2S Master Clock. */
482 	mr |= ATMEL_I2SC_MR_IMCKDIV(dev->gck_param->imckdiv);
483 	mr |= ATMEL_I2SC_MR_IMCKFS(dev->gck_param->imckfs);
484 	mr |= ATMEL_I2SC_MR_IMCKMODE_I2SMCK;
485 	ret = regmap_update_bits(dev->regmap, ATMEL_I2SC_MR, mr_mask, mr);
486 	if (ret)
487 		return ret;
488 
489 	/* Finally enable the I2S Master Clock generator. */
490 	return regmap_write(dev->regmap, ATMEL_I2SC_CR,
491 			    ATMEL_I2SC_CR_CKEN);
492 }
493 
494 static int atmel_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
495 			     struct snd_soc_dai *dai)
496 {
497 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
498 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
499 	bool is_master, mck_enabled;
500 	unsigned int cr, mr;
501 	int err;
502 
503 	switch (cmd) {
504 	case SNDRV_PCM_TRIGGER_START:
505 	case SNDRV_PCM_TRIGGER_RESUME:
506 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
507 		cr = is_playback ? ATMEL_I2SC_CR_TXEN : ATMEL_I2SC_CR_RXEN;
508 		mck_enabled = true;
509 		break;
510 	case SNDRV_PCM_TRIGGER_STOP:
511 	case SNDRV_PCM_TRIGGER_SUSPEND:
512 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
513 		cr = is_playback ? ATMEL_I2SC_CR_TXDIS : ATMEL_I2SC_CR_RXDIS;
514 		mck_enabled = false;
515 		break;
516 	default:
517 		return -EINVAL;
518 	}
519 
520 	/* Read the Mode Register to retrieve the master/slave state. */
521 	err = regmap_read(dev->regmap, ATMEL_I2SC_MR, &mr);
522 	if (err)
523 		return err;
524 	is_master = (mr & ATMEL_I2SC_MR_MODE_MASK) == ATMEL_I2SC_MR_MODE_MASTER;
525 
526 	/* If master starts, enable the audio clock. */
527 	if (is_master && mck_enabled)
528 		err = atmel_i2s_switch_mck_generator(dev, true);
529 	if (err)
530 		return err;
531 
532 	err = regmap_write(dev->regmap, ATMEL_I2SC_CR, cr);
533 	if (err)
534 		return err;
535 
536 	/* If master stops, disable the audio clock. */
537 	if (is_master && !mck_enabled)
538 		err = atmel_i2s_switch_mck_generator(dev, false);
539 
540 	return err;
541 }
542 
543 static const struct snd_soc_dai_ops atmel_i2s_dai_ops = {
544 	.prepare	= atmel_i2s_prepare,
545 	.trigger	= atmel_i2s_trigger,
546 	.hw_params	= atmel_i2s_hw_params,
547 	.set_fmt	= atmel_i2s_set_dai_fmt,
548 };
549 
550 static int atmel_i2s_dai_probe(struct snd_soc_dai *dai)
551 {
552 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
553 
554 	snd_soc_dai_init_dma_data(dai, &dev->playback, &dev->capture);
555 	return 0;
556 }
557 
558 static struct snd_soc_dai_driver atmel_i2s_dai = {
559 	.probe	= atmel_i2s_dai_probe,
560 	.playback = {
561 		.channels_min = 1,
562 		.channels_max = 2,
563 		.rates = ATMEL_I2S_RATES,
564 		.formats = ATMEL_I2S_FORMATS,
565 	},
566 	.capture = {
567 		.channels_min = 1,
568 		.channels_max = 2,
569 		.rates = ATMEL_I2S_RATES,
570 		.formats = ATMEL_I2S_FORMATS,
571 	},
572 	.ops = &atmel_i2s_dai_ops,
573 	.symmetric_rates = 1,
574 };
575 
576 static const struct snd_soc_component_driver atmel_i2s_component = {
577 	.name	= "atmel-i2s",
578 };
579 
580 static int atmel_i2s_sama5d2_mck_init(struct atmel_i2s_dev *dev,
581 				      struct device_node *np)
582 {
583 	struct clk *muxclk;
584 	int err;
585 
586 	if (!dev->gclk)
587 		return 0;
588 
589 	/* muxclk is optional, so we return error for probe defer only */
590 	muxclk = devm_clk_get(dev->dev, "muxclk");
591 	if (IS_ERR(muxclk)) {
592 		err = PTR_ERR(muxclk);
593 		if (err == -EPROBE_DEFER)
594 			return -EPROBE_DEFER;
595 		dev_warn(dev->dev,
596 			 "failed to get the I2S clock control: %d\n", err);
597 		return 0;
598 	}
599 
600 	return clk_set_parent(muxclk, dev->gclk);
601 }
602 
603 static const struct atmel_i2s_caps atmel_i2s_sama5d2_caps = {
604 	.mck_init = atmel_i2s_sama5d2_mck_init,
605 };
606 
607 static const struct of_device_id atmel_i2s_dt_ids[] = {
608 	{
609 		.compatible = "atmel,sama5d2-i2s",
610 		.data = (void *)&atmel_i2s_sama5d2_caps,
611 	},
612 
613 	{ /* sentinel */ }
614 };
615 
616 MODULE_DEVICE_TABLE(of, atmel_i2s_dt_ids);
617 
618 static int atmel_i2s_probe(struct platform_device *pdev)
619 {
620 	struct device_node *np = pdev->dev.of_node;
621 	const struct of_device_id *match;
622 	struct atmel_i2s_dev *dev;
623 	struct resource *mem;
624 	struct regmap *regmap;
625 	void __iomem *base;
626 	int irq;
627 	int err = -ENXIO;
628 	unsigned int pcm_flags = 0;
629 	unsigned int version;
630 
631 	/* Get memory for driver data. */
632 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
633 	if (!dev)
634 		return -ENOMEM;
635 
636 	/* Get hardware capabilities. */
637 	match = of_match_node(atmel_i2s_dt_ids, np);
638 	if (match)
639 		dev->caps = match->data;
640 
641 	/* Map I/O registers. */
642 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
643 	base = devm_ioremap_resource(&pdev->dev, mem);
644 	if (IS_ERR(base))
645 		return PTR_ERR(base);
646 
647 	regmap = devm_regmap_init_mmio(&pdev->dev, base,
648 				       &atmel_i2s_regmap_config);
649 	if (IS_ERR(regmap))
650 		return PTR_ERR(regmap);
651 
652 	/* Request IRQ. */
653 	irq = platform_get_irq(pdev, 0);
654 	if (irq < 0)
655 		return irq;
656 
657 	err = devm_request_irq(&pdev->dev, irq, atmel_i2s_interrupt, 0,
658 			       dev_name(&pdev->dev), dev);
659 	if (err)
660 		return err;
661 
662 	/* Get the peripheral clock. */
663 	dev->pclk = devm_clk_get(&pdev->dev, "pclk");
664 	if (IS_ERR(dev->pclk)) {
665 		err = PTR_ERR(dev->pclk);
666 		dev_err(&pdev->dev,
667 			"failed to get the peripheral clock: %d\n", err);
668 		return err;
669 	}
670 
671 	/* Get audio clocks to generate the I2S Master Clock (I2S_MCK) */
672 	dev->aclk = devm_clk_get(&pdev->dev, "aclk");
673 	dev->gclk = devm_clk_get(&pdev->dev, "gclk");
674 	if (IS_ERR(dev->aclk) && IS_ERR(dev->gclk)) {
675 		if (PTR_ERR(dev->aclk) == -EPROBE_DEFER ||
676 		    PTR_ERR(dev->gclk) == -EPROBE_DEFER)
677 			return -EPROBE_DEFER;
678 		/* Master Mode not supported */
679 		dev->aclk = NULL;
680 		dev->gclk = NULL;
681 	} else if (IS_ERR(dev->gclk)) {
682 		err = PTR_ERR(dev->gclk);
683 		dev_err(&pdev->dev,
684 			"failed to get the PMC generated clock: %d\n", err);
685 		return err;
686 	} else if (IS_ERR(dev->aclk)) {
687 		err = PTR_ERR(dev->aclk);
688 		dev_err(&pdev->dev,
689 			"failed to get the PLL audio clock: %d\n", err);
690 		return err;
691 	}
692 
693 	dev->dev = &pdev->dev;
694 	dev->regmap = regmap;
695 	platform_set_drvdata(pdev, dev);
696 
697 	/* Do hardware specific settings to initialize I2S_MCK generator */
698 	if (dev->caps && dev->caps->mck_init) {
699 		err = dev->caps->mck_init(dev, np);
700 		if (err)
701 			return err;
702 	}
703 
704 	/* Enable the peripheral clock. */
705 	err = clk_prepare_enable(dev->pclk);
706 	if (err)
707 		return err;
708 
709 	/* Get IP version. */
710 	regmap_read(dev->regmap, ATMEL_I2SC_VERSION, &version);
711 	dev_info(&pdev->dev, "hw version: %#x\n", version);
712 
713 	/* Enable error interrupts. */
714 	regmap_write(dev->regmap, ATMEL_I2SC_IER,
715 		     ATMEL_I2SC_INT_RXOR | ATMEL_I2SC_INT_TXUR);
716 
717 	err = devm_snd_soc_register_component(&pdev->dev,
718 					      &atmel_i2s_component,
719 					      &atmel_i2s_dai, 1);
720 	if (err) {
721 		dev_err(&pdev->dev, "failed to register DAI: %d\n", err);
722 		clk_disable_unprepare(dev->pclk);
723 		return err;
724 	}
725 
726 	/* Prepare DMA config. */
727 	dev->playback.addr	= (dma_addr_t)mem->start + ATMEL_I2SC_THR;
728 	dev->playback.maxburst	= 1;
729 	dev->capture.addr	= (dma_addr_t)mem->start + ATMEL_I2SC_RHR;
730 	dev->capture.maxburst	= 1;
731 
732 	if (of_property_match_string(np, "dma-names", "rx-tx") == 0)
733 		pcm_flags |= SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX;
734 	err = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, pcm_flags);
735 	if (err) {
736 		dev_err(&pdev->dev, "failed to register PCM: %d\n", err);
737 		clk_disable_unprepare(dev->pclk);
738 		return err;
739 	}
740 
741 	return 0;
742 }
743 
744 static int atmel_i2s_remove(struct platform_device *pdev)
745 {
746 	struct atmel_i2s_dev *dev = platform_get_drvdata(pdev);
747 
748 	clk_disable_unprepare(dev->pclk);
749 
750 	return 0;
751 }
752 
753 static struct platform_driver atmel_i2s_driver = {
754 	.driver		= {
755 		.name	= "atmel_i2s",
756 		.of_match_table	= of_match_ptr(atmel_i2s_dt_ids),
757 	},
758 	.probe		= atmel_i2s_probe,
759 	.remove		= atmel_i2s_remove,
760 };
761 module_platform_driver(atmel_i2s_driver);
762 
763 MODULE_DESCRIPTION("Atmel I2S Controller driver");
764 MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
765 MODULE_LICENSE("GPL v2");
766