xref: /openbmc/linux/sound/soc/atmel/atmel-i2s.c (revision 36acd5e2)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Driver for Atmel I2S controller
4  *
5  * Copyright (C) 2015 Atmel Corporation
6  *
7  * Author: Cyrille Pitchen <cyrille.pitchen@atmel.com>
8  */
9 
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/slab.h>
14 #include <linux/delay.h>
15 #include <linux/io.h>
16 #include <linux/clk.h>
17 #include <linux/mfd/syscon.h>
18 
19 #include <sound/core.h>
20 #include <sound/pcm.h>
21 #include <sound/pcm_params.h>
22 #include <sound/initval.h>
23 #include <sound/soc.h>
24 #include <sound/dmaengine_pcm.h>
25 
26 #define ATMEL_I2SC_MAX_TDM_CHANNELS	8
27 
28 /*
29  * ---- I2S Controller Register map ----
30  */
31 #define ATMEL_I2SC_CR		0x0000	/* Control Register */
32 #define ATMEL_I2SC_MR		0x0004	/* Mode Register */
33 #define ATMEL_I2SC_SR		0x0008	/* Status Register */
34 #define ATMEL_I2SC_SCR		0x000c	/* Status Clear Register */
35 #define ATMEL_I2SC_SSR		0x0010	/* Status Set Register */
36 #define ATMEL_I2SC_IER		0x0014	/* Interrupt Enable Register */
37 #define ATMEL_I2SC_IDR		0x0018	/* Interrupt Disable Register */
38 #define ATMEL_I2SC_IMR		0x001c	/* Interrupt Mask Register */
39 #define ATMEL_I2SC_RHR		0x0020	/* Receiver Holding Register */
40 #define ATMEL_I2SC_THR		0x0024	/* Transmitter Holding Register */
41 #define ATMEL_I2SC_VERSION	0x0028	/* Version Register */
42 
43 /*
44  * ---- Control Register (Write-only) ----
45  */
46 #define ATMEL_I2SC_CR_RXEN	BIT(0)	/* Receiver Enable */
47 #define ATMEL_I2SC_CR_RXDIS	BIT(1)	/* Receiver Disable */
48 #define ATMEL_I2SC_CR_CKEN	BIT(2)	/* Clock Enable */
49 #define ATMEL_I2SC_CR_CKDIS	BIT(3)	/* Clock Disable */
50 #define ATMEL_I2SC_CR_TXEN	BIT(4)	/* Transmitter Enable */
51 #define ATMEL_I2SC_CR_TXDIS	BIT(5)	/* Transmitter Disable */
52 #define ATMEL_I2SC_CR_SWRST	BIT(7)	/* Software Reset */
53 
54 /*
55  * ---- Mode Register (Read/Write) ----
56  */
57 #define ATMEL_I2SC_MR_MODE_MASK		GENMASK(0, 0)
58 #define ATMEL_I2SC_MR_MODE_SLAVE	(0 << 0)
59 #define ATMEL_I2SC_MR_MODE_MASTER	(1 << 0)
60 
61 #define ATMEL_I2SC_MR_DATALENGTH_MASK		GENMASK(4, 2)
62 #define ATMEL_I2SC_MR_DATALENGTH_32_BITS	(0 << 2)
63 #define ATMEL_I2SC_MR_DATALENGTH_24_BITS	(1 << 2)
64 #define ATMEL_I2SC_MR_DATALENGTH_20_BITS	(2 << 2)
65 #define ATMEL_I2SC_MR_DATALENGTH_18_BITS	(3 << 2)
66 #define ATMEL_I2SC_MR_DATALENGTH_16_BITS	(4 << 2)
67 #define ATMEL_I2SC_MR_DATALENGTH_16_BITS_COMPACT	(5 << 2)
68 #define ATMEL_I2SC_MR_DATALENGTH_8_BITS		(6 << 2)
69 #define ATMEL_I2SC_MR_DATALENGTH_8_BITS_COMPACT	(7 << 2)
70 
71 #define ATMEL_I2SC_MR_FORMAT_MASK	GENMASK(7, 6)
72 #define ATMEL_I2SC_MR_FORMAT_I2S	(0 << 6)
73 #define ATMEL_I2SC_MR_FORMAT_LJ		(1 << 6)  /* Left Justified */
74 #define ATMEL_I2SC_MR_FORMAT_TDM	(2 << 6)
75 #define ATMEL_I2SC_MR_FORMAT_TDMLJ	(3 << 6)
76 
77 /* Left audio samples duplicated to right audio channel */
78 #define ATMEL_I2SC_MR_RXMONO		BIT(8)
79 
80 /* Receiver uses one DMA channel ... */
81 #define ATMEL_I2SC_MR_RXDMA_MASK	GENMASK(9, 9)
82 #define ATMEL_I2SC_MR_RXDMA_SINGLE	(0 << 9)  /* for all audio channels */
83 #define ATMEL_I2SC_MR_RXDMA_MULTIPLE	(1 << 9)  /* per audio channel */
84 
85 /* I2SDO output of I2SC is internally connected to I2SDI input */
86 #define ATMEL_I2SC_MR_RXLOOP		BIT(10)
87 
88 /* Left audio samples duplicated to right audio channel */
89 #define ATMEL_I2SC_MR_TXMONO		BIT(12)
90 
91 /* Transmitter uses one DMA channel ... */
92 #define ATMEL_I2SC_MR_TXDMA_MASK	GENMASK(13, 13)
93 #define ATMEL_I2SC_MR_TXDMA_SINGLE	(0 << 13)  /* for all audio channels */
94 #define ATMEL_I2SC_MR_TXDME_MULTIPLE	(1 << 13)  /* per audio channel */
95 
96 /* x sample transmitted when underrun */
97 #define ATMEL_I2SC_MR_TXSAME_MASK	GENMASK(14, 14)
98 #define ATMEL_I2SC_MR_TXSAME_ZERO	(0 << 14)  /* Zero sample */
99 #define ATMEL_I2SC_MR_TXSAME_PREVIOUS	(1 << 14)  /* Previous sample */
100 
101 /* Audio Clock to I2SC Master Clock ratio */
102 #define ATMEL_I2SC_MR_IMCKDIV_MASK	GENMASK(21, 16)
103 #define ATMEL_I2SC_MR_IMCKDIV(div) \
104 	(((div) << 16) & ATMEL_I2SC_MR_IMCKDIV_MASK)
105 
106 /* Master Clock to fs ratio */
107 #define ATMEL_I2SC_MR_IMCKFS_MASK	GENMASK(29, 24)
108 #define ATMEL_I2SC_MR_IMCKFS(fs) \
109 	(((fs) << 24) & ATMEL_I2SC_MR_IMCKFS_MASK)
110 
111 /* Master Clock mode */
112 #define ATMEL_I2SC_MR_IMCKMODE_MASK	GENMASK(30, 30)
113 /* 0: No master clock generated (selected clock drives I2SCK pin) */
114 #define ATMEL_I2SC_MR_IMCKMODE_I2SCK	(0 << 30)
115 /* 1: master clock generated (internally generated clock drives I2SMCK pin) */
116 #define ATMEL_I2SC_MR_IMCKMODE_I2SMCK	(1 << 30)
117 
118 /* Slot Width */
119 /* 0: slot is 32 bits wide for DATALENGTH = 18/20/24 bits. */
120 /* 1: slot is 24 bits wide for DATALENGTH = 18/20/24 bits. */
121 #define ATMEL_I2SC_MR_IWS		BIT(31)
122 
123 /*
124  * ---- Status Registers ----
125  */
126 #define ATMEL_I2SC_SR_RXEN	BIT(0)	/* Receiver Enabled */
127 #define ATMEL_I2SC_SR_RXRDY	BIT(1)	/* Receive Ready */
128 #define ATMEL_I2SC_SR_RXOR	BIT(2)	/* Receive Overrun */
129 
130 #define ATMEL_I2SC_SR_TXEN	BIT(4)	/* Transmitter Enabled */
131 #define ATMEL_I2SC_SR_TXRDY	BIT(5)	/* Transmit Ready */
132 #define ATMEL_I2SC_SR_TXUR	BIT(6)	/* Transmit Underrun */
133 
134 /* Receive Overrun Channel */
135 #define ATMEL_I2SC_SR_RXORCH_MASK	GENMASK(15, 8)
136 #define ATMEL_I2SC_SR_RXORCH(ch)	(1 << (((ch) & 0x7) + 8))
137 
138 /* Transmit Underrun Channel */
139 #define ATMEL_I2SC_SR_TXURCH_MASK	GENMASK(27, 20)
140 #define ATMEL_I2SC_SR_TXURCH(ch)	(1 << (((ch) & 0x7) + 20))
141 
142 /*
143  * ---- Interrupt Enable/Disable/Mask Registers ----
144  */
145 #define ATMEL_I2SC_INT_RXRDY	ATMEL_I2SC_SR_RXRDY
146 #define ATMEL_I2SC_INT_RXOR	ATMEL_I2SC_SR_RXOR
147 #define ATMEL_I2SC_INT_TXRDY	ATMEL_I2SC_SR_TXRDY
148 #define ATMEL_I2SC_INT_TXUR	ATMEL_I2SC_SR_TXUR
149 
150 static const struct regmap_config atmel_i2s_regmap_config = {
151 	.reg_bits = 32,
152 	.reg_stride = 4,
153 	.val_bits = 32,
154 	.max_register = ATMEL_I2SC_VERSION,
155 };
156 
157 struct atmel_i2s_gck_param {
158 	int		fs;
159 	unsigned long	mck;
160 	int		imckdiv;
161 	int		imckfs;
162 };
163 
164 #define I2S_MCK_12M288		12288000UL
165 #define I2S_MCK_11M2896		11289600UL
166 
167 /* mck = (32 * (imckfs+1) / (imckdiv+1)) * fs */
168 static const struct atmel_i2s_gck_param gck_params[] = {
169 	/* mck = 12.288MHz */
170 	{  8000, I2S_MCK_12M288, 0, 47},	/* mck = 1536 fs */
171 	{ 16000, I2S_MCK_12M288, 1, 47},	/* mck =  768 fs */
172 	{ 24000, I2S_MCK_12M288, 3, 63},	/* mck =  512 fs */
173 	{ 32000, I2S_MCK_12M288, 3, 47},	/* mck =  384 fs */
174 	{ 48000, I2S_MCK_12M288, 7, 63},	/* mck =  256 fs */
175 	{ 64000, I2S_MCK_12M288, 7, 47},	/* mck =  192 fs */
176 	{ 96000, I2S_MCK_12M288, 7, 31},	/* mck =  128 fs */
177 	{192000, I2S_MCK_12M288, 7, 15},	/* mck =   64 fs */
178 
179 	/* mck = 11.2896MHz */
180 	{ 11025, I2S_MCK_11M2896, 1, 63},	/* mck = 1024 fs */
181 	{ 22050, I2S_MCK_11M2896, 3, 63},	/* mck =  512 fs */
182 	{ 44100, I2S_MCK_11M2896, 7, 63},	/* mck =  256 fs */
183 	{ 88200, I2S_MCK_11M2896, 7, 31},	/* mck =  128 fs */
184 	{176400, I2S_MCK_11M2896, 7, 15},	/* mck =   64 fs */
185 };
186 
187 struct atmel_i2s_dev;
188 
189 struct atmel_i2s_caps {
190 	int	(*mck_init)(struct atmel_i2s_dev *, struct device_node *np);
191 };
192 
193 struct atmel_i2s_dev {
194 	struct device				*dev;
195 	struct regmap				*regmap;
196 	struct clk				*pclk;
197 	struct clk				*gclk;
198 	struct snd_dmaengine_dai_dma_data	playback;
199 	struct snd_dmaengine_dai_dma_data	capture;
200 	unsigned int				fmt;
201 	const struct atmel_i2s_gck_param	*gck_param;
202 	const struct atmel_i2s_caps		*caps;
203 };
204 
205 static irqreturn_t atmel_i2s_interrupt(int irq, void *dev_id)
206 {
207 	struct atmel_i2s_dev *dev = dev_id;
208 	unsigned int sr, imr, pending, ch, mask;
209 	irqreturn_t ret = IRQ_NONE;
210 
211 	regmap_read(dev->regmap, ATMEL_I2SC_SR, &sr);
212 	regmap_read(dev->regmap, ATMEL_I2SC_IMR, &imr);
213 	pending = sr & imr;
214 
215 	if (!pending)
216 		return IRQ_NONE;
217 
218 	if (pending & ATMEL_I2SC_INT_RXOR) {
219 		mask = ATMEL_I2SC_SR_RXOR;
220 
221 		for (ch = 0; ch < ATMEL_I2SC_MAX_TDM_CHANNELS; ++ch) {
222 			if (sr & ATMEL_I2SC_SR_RXORCH(ch)) {
223 				mask |= ATMEL_I2SC_SR_RXORCH(ch);
224 				dev_err(dev->dev,
225 					"RX overrun on channel %d\n", ch);
226 			}
227 		}
228 		regmap_write(dev->regmap, ATMEL_I2SC_SCR, mask);
229 		ret = IRQ_HANDLED;
230 	}
231 
232 	if (pending & ATMEL_I2SC_INT_TXUR) {
233 		mask = ATMEL_I2SC_SR_TXUR;
234 
235 		for (ch = 0; ch < ATMEL_I2SC_MAX_TDM_CHANNELS; ++ch) {
236 			if (sr & ATMEL_I2SC_SR_TXURCH(ch)) {
237 				mask |= ATMEL_I2SC_SR_TXURCH(ch);
238 				dev_err(dev->dev,
239 					"TX underrun on channel %d\n", ch);
240 			}
241 		}
242 		regmap_write(dev->regmap, ATMEL_I2SC_SCR, mask);
243 		ret = IRQ_HANDLED;
244 	}
245 
246 	return ret;
247 }
248 
249 #define ATMEL_I2S_RATES		SNDRV_PCM_RATE_8000_192000
250 
251 #define ATMEL_I2S_FORMATS	(SNDRV_PCM_FMTBIT_S8 |		\
252 				 SNDRV_PCM_FMTBIT_S16_LE |	\
253 				 SNDRV_PCM_FMTBIT_S18_3LE |	\
254 				 SNDRV_PCM_FMTBIT_S20_3LE |	\
255 				 SNDRV_PCM_FMTBIT_S24_3LE |	\
256 				 SNDRV_PCM_FMTBIT_S24_LE |	\
257 				 SNDRV_PCM_FMTBIT_S32_LE)
258 
259 static int atmel_i2s_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
260 {
261 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
262 
263 	dev->fmt = fmt;
264 	return 0;
265 }
266 
267 static int atmel_i2s_prepare(struct snd_pcm_substream *substream,
268 			     struct snd_soc_dai *dai)
269 {
270 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
271 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
272 	unsigned int rhr, sr = 0;
273 
274 	if (is_playback) {
275 		regmap_read(dev->regmap, ATMEL_I2SC_SR, &sr);
276 		if (sr & ATMEL_I2SC_SR_RXRDY) {
277 			/*
278 			 * The RX Ready flag should not be set. However if here,
279 			 * we flush (read) the Receive Holding Register to start
280 			 * from a clean state.
281 			 */
282 			dev_dbg(dev->dev, "RXRDY is set\n");
283 			regmap_read(dev->regmap, ATMEL_I2SC_RHR, &rhr);
284 		}
285 	}
286 
287 	return 0;
288 }
289 
290 static int atmel_i2s_get_gck_param(struct atmel_i2s_dev *dev, int fs)
291 {
292 	int i, best;
293 
294 	if (!dev->gclk) {
295 		dev_err(dev->dev, "cannot generate the I2S Master Clock\n");
296 		return -EINVAL;
297 	}
298 
299 	/*
300 	 * Find the best possible settings to generate the I2S Master Clock
301 	 * from the PLL Audio.
302 	 */
303 	dev->gck_param = NULL;
304 	best = INT_MAX;
305 	for (i = 0; i < ARRAY_SIZE(gck_params); ++i) {
306 		const struct atmel_i2s_gck_param *gck_param = &gck_params[i];
307 		int val = abs(fs - gck_param->fs);
308 
309 		if (val < best) {
310 			best = val;
311 			dev->gck_param = gck_param;
312 		}
313 	}
314 
315 	return 0;
316 }
317 
318 static int atmel_i2s_hw_params(struct snd_pcm_substream *substream,
319 			       struct snd_pcm_hw_params *params,
320 			       struct snd_soc_dai *dai)
321 {
322 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
323 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
324 	unsigned int mr = 0;
325 	int ret;
326 
327 	switch (dev->fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
328 	case SND_SOC_DAIFMT_I2S:
329 		mr |= ATMEL_I2SC_MR_FORMAT_I2S;
330 		break;
331 
332 	default:
333 		dev_err(dev->dev, "unsupported bus format\n");
334 		return -EINVAL;
335 	}
336 
337 	switch (dev->fmt & SND_SOC_DAIFMT_MASTER_MASK) {
338 	case SND_SOC_DAIFMT_CBS_CFS:
339 		/* codec is slave, so cpu is master */
340 		mr |= ATMEL_I2SC_MR_MODE_MASTER;
341 		ret = atmel_i2s_get_gck_param(dev, params_rate(params));
342 		if (ret)
343 			return ret;
344 		break;
345 
346 	case SND_SOC_DAIFMT_CBM_CFM:
347 		/* codec is master, so cpu is slave */
348 		mr |= ATMEL_I2SC_MR_MODE_SLAVE;
349 		dev->gck_param = NULL;
350 		break;
351 
352 	default:
353 		dev_err(dev->dev, "unsupported master/slave mode\n");
354 		return -EINVAL;
355 	}
356 
357 	switch (params_channels(params)) {
358 	case 1:
359 		if (is_playback)
360 			mr |= ATMEL_I2SC_MR_TXMONO;
361 		else
362 			mr |= ATMEL_I2SC_MR_RXMONO;
363 		break;
364 	case 2:
365 		break;
366 	default:
367 		dev_err(dev->dev, "unsupported number of audio channels\n");
368 		return -EINVAL;
369 	}
370 
371 	switch (params_format(params)) {
372 	case SNDRV_PCM_FORMAT_S8:
373 		mr |= ATMEL_I2SC_MR_DATALENGTH_8_BITS;
374 		break;
375 
376 	case SNDRV_PCM_FORMAT_S16_LE:
377 		mr |= ATMEL_I2SC_MR_DATALENGTH_16_BITS;
378 		break;
379 
380 	case SNDRV_PCM_FORMAT_S18_3LE:
381 		mr |= ATMEL_I2SC_MR_DATALENGTH_18_BITS | ATMEL_I2SC_MR_IWS;
382 		break;
383 
384 	case SNDRV_PCM_FORMAT_S20_3LE:
385 		mr |= ATMEL_I2SC_MR_DATALENGTH_20_BITS | ATMEL_I2SC_MR_IWS;
386 		break;
387 
388 	case SNDRV_PCM_FORMAT_S24_3LE:
389 		mr |= ATMEL_I2SC_MR_DATALENGTH_24_BITS | ATMEL_I2SC_MR_IWS;
390 		break;
391 
392 	case SNDRV_PCM_FORMAT_S24_LE:
393 		mr |= ATMEL_I2SC_MR_DATALENGTH_24_BITS;
394 		break;
395 
396 	case SNDRV_PCM_FORMAT_S32_LE:
397 		mr |= ATMEL_I2SC_MR_DATALENGTH_32_BITS;
398 		break;
399 
400 	default:
401 		dev_err(dev->dev, "unsupported size/endianness for audio samples\n");
402 		return -EINVAL;
403 	}
404 
405 	return regmap_write(dev->regmap, ATMEL_I2SC_MR, mr);
406 }
407 
408 static int atmel_i2s_switch_mck_generator(struct atmel_i2s_dev *dev,
409 					  bool enabled)
410 {
411 	unsigned int mr, mr_mask;
412 	unsigned long gclk_rate;
413 	int ret;
414 
415 	mr = 0;
416 	mr_mask = (ATMEL_I2SC_MR_IMCKDIV_MASK |
417 		   ATMEL_I2SC_MR_IMCKFS_MASK |
418 		   ATMEL_I2SC_MR_IMCKMODE_MASK);
419 
420 	if (!enabled) {
421 		/* Disable the I2S Master Clock generator. */
422 		ret = regmap_write(dev->regmap, ATMEL_I2SC_CR,
423 				   ATMEL_I2SC_CR_CKDIS);
424 		if (ret)
425 			return ret;
426 
427 		/* Reset the I2S Master Clock generator settings. */
428 		ret = regmap_update_bits(dev->regmap, ATMEL_I2SC_MR,
429 					 mr_mask, mr);
430 		if (ret)
431 			return ret;
432 
433 		/* Disable/unprepare the PMC generated clock. */
434 		clk_disable_unprepare(dev->gclk);
435 
436 		return 0;
437 	}
438 
439 	if (!dev->gck_param)
440 		return -EINVAL;
441 
442 	gclk_rate = dev->gck_param->mck * (dev->gck_param->imckdiv + 1);
443 
444 	ret = clk_set_rate(dev->gclk, gclk_rate);
445 	if (ret)
446 		return ret;
447 
448 	ret = clk_prepare_enable(dev->gclk);
449 	if (ret)
450 		return ret;
451 
452 	/* Update the Mode Register to generate the I2S Master Clock. */
453 	mr |= ATMEL_I2SC_MR_IMCKDIV(dev->gck_param->imckdiv);
454 	mr |= ATMEL_I2SC_MR_IMCKFS(dev->gck_param->imckfs);
455 	mr |= ATMEL_I2SC_MR_IMCKMODE_I2SMCK;
456 	ret = regmap_update_bits(dev->regmap, ATMEL_I2SC_MR, mr_mask, mr);
457 	if (ret)
458 		return ret;
459 
460 	/* Finally enable the I2S Master Clock generator. */
461 	return regmap_write(dev->regmap, ATMEL_I2SC_CR,
462 			    ATMEL_I2SC_CR_CKEN);
463 }
464 
465 static int atmel_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
466 			     struct snd_soc_dai *dai)
467 {
468 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
469 	bool is_playback = (substream->stream == SNDRV_PCM_STREAM_PLAYBACK);
470 	bool is_master, mck_enabled;
471 	unsigned int cr, mr;
472 	int err;
473 
474 	switch (cmd) {
475 	case SNDRV_PCM_TRIGGER_START:
476 	case SNDRV_PCM_TRIGGER_RESUME:
477 	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
478 		cr = is_playback ? ATMEL_I2SC_CR_TXEN : ATMEL_I2SC_CR_RXEN;
479 		mck_enabled = true;
480 		break;
481 	case SNDRV_PCM_TRIGGER_STOP:
482 	case SNDRV_PCM_TRIGGER_SUSPEND:
483 	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
484 		cr = is_playback ? ATMEL_I2SC_CR_TXDIS : ATMEL_I2SC_CR_RXDIS;
485 		mck_enabled = false;
486 		break;
487 	default:
488 		return -EINVAL;
489 	}
490 
491 	/* Read the Mode Register to retrieve the master/slave state. */
492 	err = regmap_read(dev->regmap, ATMEL_I2SC_MR, &mr);
493 	if (err)
494 		return err;
495 	is_master = (mr & ATMEL_I2SC_MR_MODE_MASK) == ATMEL_I2SC_MR_MODE_MASTER;
496 
497 	/* If master starts, enable the audio clock. */
498 	if (is_master && mck_enabled)
499 		err = atmel_i2s_switch_mck_generator(dev, true);
500 	if (err)
501 		return err;
502 
503 	err = regmap_write(dev->regmap, ATMEL_I2SC_CR, cr);
504 	if (err)
505 		return err;
506 
507 	/* If master stops, disable the audio clock. */
508 	if (is_master && !mck_enabled)
509 		err = atmel_i2s_switch_mck_generator(dev, false);
510 
511 	return err;
512 }
513 
514 static const struct snd_soc_dai_ops atmel_i2s_dai_ops = {
515 	.prepare	= atmel_i2s_prepare,
516 	.trigger	= atmel_i2s_trigger,
517 	.hw_params	= atmel_i2s_hw_params,
518 	.set_fmt	= atmel_i2s_set_dai_fmt,
519 };
520 
521 static int atmel_i2s_dai_probe(struct snd_soc_dai *dai)
522 {
523 	struct atmel_i2s_dev *dev = snd_soc_dai_get_drvdata(dai);
524 
525 	snd_soc_dai_init_dma_data(dai, &dev->playback, &dev->capture);
526 	return 0;
527 }
528 
529 static struct snd_soc_dai_driver atmel_i2s_dai = {
530 	.probe	= atmel_i2s_dai_probe,
531 	.playback = {
532 		.channels_min = 1,
533 		.channels_max = 2,
534 		.rates = ATMEL_I2S_RATES,
535 		.formats = ATMEL_I2S_FORMATS,
536 	},
537 	.capture = {
538 		.channels_min = 1,
539 		.channels_max = 2,
540 		.rates = ATMEL_I2S_RATES,
541 		.formats = ATMEL_I2S_FORMATS,
542 	},
543 	.ops = &atmel_i2s_dai_ops,
544 	.symmetric_rates = 1,
545 };
546 
547 static const struct snd_soc_component_driver atmel_i2s_component = {
548 	.name	= "atmel-i2s",
549 };
550 
551 static int atmel_i2s_sama5d2_mck_init(struct atmel_i2s_dev *dev,
552 				      struct device_node *np)
553 {
554 	struct clk *muxclk;
555 	int err;
556 
557 	if (!dev->gclk)
558 		return 0;
559 
560 	/* muxclk is optional, so we return error for probe defer only */
561 	muxclk = devm_clk_get(dev->dev, "muxclk");
562 	if (IS_ERR(muxclk)) {
563 		err = PTR_ERR(muxclk);
564 		if (err == -EPROBE_DEFER)
565 			return -EPROBE_DEFER;
566 		dev_dbg(dev->dev,
567 			"failed to get the I2S clock control: %d\n", err);
568 		return 0;
569 	}
570 
571 	return clk_set_parent(muxclk, dev->gclk);
572 }
573 
574 static const struct atmel_i2s_caps atmel_i2s_sama5d2_caps = {
575 	.mck_init = atmel_i2s_sama5d2_mck_init,
576 };
577 
578 static const struct of_device_id atmel_i2s_dt_ids[] = {
579 	{
580 		.compatible = "atmel,sama5d2-i2s",
581 		.data = (void *)&atmel_i2s_sama5d2_caps,
582 	},
583 
584 	{ /* sentinel */ }
585 };
586 
587 MODULE_DEVICE_TABLE(of, atmel_i2s_dt_ids);
588 
589 static int atmel_i2s_probe(struct platform_device *pdev)
590 {
591 	struct device_node *np = pdev->dev.of_node;
592 	const struct of_device_id *match;
593 	struct atmel_i2s_dev *dev;
594 	struct resource *mem;
595 	struct regmap *regmap;
596 	void __iomem *base;
597 	int irq;
598 	int err = -ENXIO;
599 	unsigned int pcm_flags = 0;
600 	unsigned int version;
601 
602 	/* Get memory for driver data. */
603 	dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
604 	if (!dev)
605 		return -ENOMEM;
606 
607 	/* Get hardware capabilities. */
608 	match = of_match_node(atmel_i2s_dt_ids, np);
609 	if (match)
610 		dev->caps = match->data;
611 
612 	/* Map I/O registers. */
613 	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
614 	base = devm_ioremap_resource(&pdev->dev, mem);
615 	if (IS_ERR(base))
616 		return PTR_ERR(base);
617 
618 	regmap = devm_regmap_init_mmio(&pdev->dev, base,
619 				       &atmel_i2s_regmap_config);
620 	if (IS_ERR(regmap))
621 		return PTR_ERR(regmap);
622 
623 	/* Request IRQ. */
624 	irq = platform_get_irq(pdev, 0);
625 	if (irq < 0)
626 		return irq;
627 
628 	err = devm_request_irq(&pdev->dev, irq, atmel_i2s_interrupt, 0,
629 			       dev_name(&pdev->dev), dev);
630 	if (err)
631 		return err;
632 
633 	/* Get the peripheral clock. */
634 	dev->pclk = devm_clk_get(&pdev->dev, "pclk");
635 	if (IS_ERR(dev->pclk)) {
636 		err = PTR_ERR(dev->pclk);
637 		dev_err(&pdev->dev,
638 			"failed to get the peripheral clock: %d\n", err);
639 		return err;
640 	}
641 
642 	/* Get audio clock to generate the I2S Master Clock (I2S_MCK) */
643 	dev->gclk = devm_clk_get(&pdev->dev, "gclk");
644 	if (IS_ERR(dev->gclk)) {
645 		if (PTR_ERR(dev->gclk) == -EPROBE_DEFER)
646 			return -EPROBE_DEFER;
647 		/* Master Mode not supported */
648 		dev->gclk = NULL;
649 	}
650 	dev->dev = &pdev->dev;
651 	dev->regmap = regmap;
652 	platform_set_drvdata(pdev, dev);
653 
654 	/* Do hardware specific settings to initialize I2S_MCK generator */
655 	if (dev->caps && dev->caps->mck_init) {
656 		err = dev->caps->mck_init(dev, np);
657 		if (err)
658 			return err;
659 	}
660 
661 	/* Enable the peripheral clock. */
662 	err = clk_prepare_enable(dev->pclk);
663 	if (err)
664 		return err;
665 
666 	/* Get IP version. */
667 	regmap_read(dev->regmap, ATMEL_I2SC_VERSION, &version);
668 	dev_info(&pdev->dev, "hw version: %#x\n", version);
669 
670 	/* Enable error interrupts. */
671 	regmap_write(dev->regmap, ATMEL_I2SC_IER,
672 		     ATMEL_I2SC_INT_RXOR | ATMEL_I2SC_INT_TXUR);
673 
674 	err = devm_snd_soc_register_component(&pdev->dev,
675 					      &atmel_i2s_component,
676 					      &atmel_i2s_dai, 1);
677 	if (err) {
678 		dev_err(&pdev->dev, "failed to register DAI: %d\n", err);
679 		clk_disable_unprepare(dev->pclk);
680 		return err;
681 	}
682 
683 	/* Prepare DMA config. */
684 	dev->playback.addr	= (dma_addr_t)mem->start + ATMEL_I2SC_THR;
685 	dev->playback.maxburst	= 1;
686 	dev->capture.addr	= (dma_addr_t)mem->start + ATMEL_I2SC_RHR;
687 	dev->capture.maxburst	= 1;
688 
689 	if (of_property_match_string(np, "dma-names", "rx-tx") == 0)
690 		pcm_flags |= SND_DMAENGINE_PCM_FLAG_HALF_DUPLEX;
691 	err = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, pcm_flags);
692 	if (err) {
693 		dev_err(&pdev->dev, "failed to register PCM: %d\n", err);
694 		clk_disable_unprepare(dev->pclk);
695 		return err;
696 	}
697 
698 	return 0;
699 }
700 
701 static int atmel_i2s_remove(struct platform_device *pdev)
702 {
703 	struct atmel_i2s_dev *dev = platform_get_drvdata(pdev);
704 
705 	clk_disable_unprepare(dev->pclk);
706 
707 	return 0;
708 }
709 
710 static struct platform_driver atmel_i2s_driver = {
711 	.driver		= {
712 		.name	= "atmel_i2s",
713 		.of_match_table	= of_match_ptr(atmel_i2s_dt_ids),
714 	},
715 	.probe		= atmel_i2s_probe,
716 	.remove		= atmel_i2s_remove,
717 };
718 module_platform_driver(atmel_i2s_driver);
719 
720 MODULE_DESCRIPTION("Atmel I2S Controller driver");
721 MODULE_AUTHOR("Cyrille Pitchen <cyrille.pitchen@atmel.com>");
722 MODULE_LICENSE("GPL v2");
723