1/*
2 * CS4270 ALSA SoC (ASoC) codec driver
3 *
4 * Author: Timur Tabi <timur@freescale.com>
5 *
6 * Copyright 2007-2009 Freescale Semiconductor, Inc.  This file is licensed
7 * under the terms of the GNU General Public License version 2.  This
8 * program is licensed "as is" without any warranty of any kind, whether
9 * express or implied.
10 *
11 * This is an ASoC device driver for the Cirrus Logic CS4270 codec.
12 *
13 * Current features/limitations:
14 *
15 * - Software mode is supported.  Stand-alone mode is not supported.
16 * - Only I2C is supported, not SPI
17 * - Support for master and slave mode
18 * - The machine driver's 'startup' function must call
19 *   cs4270_set_dai_sysclk() with the value of MCLK.
20 * - Only I2S and left-justified modes are supported
21 * - Power management is supported
22 */
23
24#include <linux/module.h>
25#include <linux/slab.h>
26#include <sound/core.h>
27#include <sound/soc.h>
28#include <sound/initval.h>
29#include <linux/i2c.h>
30#include <linux/delay.h>
31#include <linux/regulator/consumer.h>
32#include <linux/of_device.h>
33#include <linux/of_gpio.h>
34
35/*
36 * The codec isn't really big-endian or little-endian, since the I2S
37 * interface requires data to be sent serially with the MSbit first.
38 * However, to support BE and LE I2S devices, we specify both here.  That
39 * way, ALSA will always match the bit patterns.
40 */
41#define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
42			SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
43			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
44			SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
45			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
46			SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
47
48/* CS4270 registers addresses */
49#define CS4270_CHIPID	0x01	/* Chip ID */
50#define CS4270_PWRCTL	0x02	/* Power Control */
51#define CS4270_MODE	0x03	/* Mode Control */
52#define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
53#define CS4270_TRANS	0x05	/* Transition Control */
54#define CS4270_MUTE	0x06	/* Mute Control */
55#define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
56#define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
57
58#define CS4270_FIRSTREG	0x01
59#define CS4270_LASTREG	0x08
60#define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
61#define CS4270_I2C_INCR	0x80
62
63/* Bit masks for the CS4270 registers */
64#define CS4270_CHIPID_ID	0xF0
65#define CS4270_CHIPID_REV	0x0F
66#define CS4270_PWRCTL_FREEZE	0x80
67#define CS4270_PWRCTL_PDN_ADC	0x20
68#define CS4270_PWRCTL_PDN_DAC	0x02
69#define CS4270_PWRCTL_PDN	0x01
70#define CS4270_PWRCTL_PDN_ALL	\
71	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
72#define CS4270_MODE_SPEED_MASK	0x30
73#define CS4270_MODE_1X		0x00
74#define CS4270_MODE_2X		0x10
75#define CS4270_MODE_4X		0x20
76#define CS4270_MODE_SLAVE	0x30
77#define CS4270_MODE_DIV_MASK	0x0E
78#define CS4270_MODE_DIV1	0x00
79#define CS4270_MODE_DIV15	0x02
80#define CS4270_MODE_DIV2	0x04
81#define CS4270_MODE_DIV3	0x06
82#define CS4270_MODE_DIV4	0x08
83#define CS4270_MODE_POPGUARD	0x01
84#define CS4270_FORMAT_FREEZE_A	0x80
85#define CS4270_FORMAT_FREEZE_B	0x40
86#define CS4270_FORMAT_LOOPBACK	0x20
87#define CS4270_FORMAT_DAC_MASK	0x18
88#define CS4270_FORMAT_DAC_LJ	0x00
89#define CS4270_FORMAT_DAC_I2S	0x08
90#define CS4270_FORMAT_DAC_RJ16	0x18
91#define CS4270_FORMAT_DAC_RJ24	0x10
92#define CS4270_FORMAT_ADC_MASK	0x01
93#define CS4270_FORMAT_ADC_LJ	0x00
94#define CS4270_FORMAT_ADC_I2S	0x01
95#define CS4270_TRANS_ONE_VOL	0x80
96#define CS4270_TRANS_SOFT	0x40
97#define CS4270_TRANS_ZERO	0x20
98#define CS4270_TRANS_INV_ADC_A	0x08
99#define CS4270_TRANS_INV_ADC_B	0x10
100#define CS4270_TRANS_INV_DAC_A	0x02
101#define CS4270_TRANS_INV_DAC_B	0x04
102#define CS4270_TRANS_DEEMPH	0x01
103#define CS4270_MUTE_AUTO	0x20
104#define CS4270_MUTE_ADC_A	0x08
105#define CS4270_MUTE_ADC_B	0x10
106#define CS4270_MUTE_POLARITY	0x04
107#define CS4270_MUTE_DAC_A	0x01
108#define CS4270_MUTE_DAC_B	0x02
109
110/* Power-on default values for the registers
111 *
112 * This array contains the power-on default values of the registers, with the
113 * exception of the "CHIPID" register (01h).  The lower four bits of that
114 * register contain the hardware revision, so it is treated as volatile.
115 */
116static const struct reg_default cs4270_reg_defaults[] = {
117	{ 2, 0x00 },
118	{ 3, 0x30 },
119	{ 4, 0x00 },
120	{ 5, 0x60 },
121	{ 6, 0x20 },
122	{ 7, 0x00 },
123	{ 8, 0x00 },
124};
125
126static const char *supply_names[] = {
127	"va", "vd", "vlc"
128};
129
130/* Private data for the CS4270 */
131struct cs4270_private {
132	struct regmap *regmap;
133	unsigned int mclk; /* Input frequency of the MCLK pin */
134	unsigned int mode; /* The mode (I2S or left-justified) */
135	unsigned int slave_mode;
136	unsigned int manual_mute;
137
138	/* power domain regulators */
139	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
140};
141
142static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {
143SND_SOC_DAPM_INPUT("AINL"),
144SND_SOC_DAPM_INPUT("AINR"),
145
146SND_SOC_DAPM_OUTPUT("AOUTL"),
147SND_SOC_DAPM_OUTPUT("AOUTR"),
148};
149
150static const struct snd_soc_dapm_route cs4270_dapm_routes[] = {
151	{ "Capture", NULL, "AINA" },
152	{ "Capture", NULL, "AINB" },
153
154	{ "AOUTA", NULL, "Playback" },
155	{ "AOUTB", NULL, "Playback" },
156};
157
158/**
159 * struct cs4270_mode_ratios - clock ratio tables
160 * @ratio: the ratio of MCLK to the sample rate
161 * @speed_mode: the Speed Mode bits to set in the Mode Control register for
162 *              this ratio
163 * @mclk: the Ratio Select bits to set in the Mode Control register for this
164 *        ratio
165 *
166 * The data for this chart is taken from Table 5 of the CS4270 reference
167 * manual.
168 *
169 * This table is used to determine how to program the Mode Control register.
170 * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
171 * rates the CS4270 currently supports.
172 *
173 * @speed_mode is the corresponding bit pattern to be written to the
174 * MODE bits of the Mode Control Register
175 *
176 * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
177 * the Mode Control Register.
178 *
179 * In situations where a single ratio is represented by multiple speed
180 * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
181 * double-speed instead of quad-speed.  However, the CS4270 errata states
182 * that divide-By-1.5 can cause failures, so we avoid that mode where
183 * possible.
184 *
185 * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
186 * work if Vd is 3.3V.  If this effects you, select the
187 * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
188 * never select any sample rates that require divide-by-1.5.
189 */
190struct cs4270_mode_ratios {
191	unsigned int ratio;
192	u8 speed_mode;
193	u8 mclk;
194};
195
196static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
197	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
198#ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
199	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
200#endif
201	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
202	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
203	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
204	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
205	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
206	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
207	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
208};
209
210/* The number of MCLK/LRCK ratios supported by the CS4270 */
211#define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
212
213static bool cs4270_reg_is_readable(struct device *dev, unsigned int reg)
214{
215	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);
216}
217
218static bool cs4270_reg_is_volatile(struct device *dev, unsigned int reg)
219{
220	/* Unreadable registers are considered volatile */
221	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
222		return 1;
223
224	return reg == CS4270_CHIPID;
225}
226
227/**
228 * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
229 * @codec_dai: the codec DAI
230 * @clk_id: the clock ID (ignored)
231 * @freq: the MCLK input frequency
232 * @dir: the clock direction (ignored)
233 *
234 * This function is used to tell the codec driver what the input MCLK
235 * frequency is.
236 *
237 * The value of MCLK is used to determine which sample rates are supported
238 * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
239 * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
240 *
241 * This function calculates the nine ratios and determines which ones match
242 * a standard sample rate.  If there's a match, then it is added to the list
243 * of supported sample rates.
244 *
245 * This function must be called by the machine driver's 'startup' function,
246 * otherwise the list of supported sample rates will not be available in
247 * time for ALSA.
248 *
249 * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
250 * theoretically possible sample rates to be enabled. Call it again with a
251 * proper value set one the external clock is set (most probably you would do
252 * that from a machine's driver 'hw_param' hook.
253 */
254static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
255				 int clk_id, unsigned int freq, int dir)
256{
257	struct snd_soc_codec *codec = codec_dai->codec;
258	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
259
260	cs4270->mclk = freq;
261	return 0;
262}
263
264/**
265 * cs4270_set_dai_fmt - configure the codec for the selected audio format
266 * @codec_dai: the codec DAI
267 * @format: a SND_SOC_DAIFMT_x value indicating the data format
268 *
269 * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
270 * codec accordingly.
271 *
272 * Currently, this function only supports SND_SOC_DAIFMT_I2S and
273 * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
274 * data for playback only, but ASoC currently does not support different
275 * formats for playback vs. record.
276 */
277static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
278			      unsigned int format)
279{
280	struct snd_soc_codec *codec = codec_dai->codec;
281	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
282
283	/* set DAI format */
284	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
285	case SND_SOC_DAIFMT_I2S:
286	case SND_SOC_DAIFMT_LEFT_J:
287		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
288		break;
289	default:
290		dev_err(codec->dev, "invalid dai format\n");
291		return -EINVAL;
292	}
293
294	/* set master/slave audio interface */
295	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
296	case SND_SOC_DAIFMT_CBS_CFS:
297		cs4270->slave_mode = 1;
298		break;
299	case SND_SOC_DAIFMT_CBM_CFM:
300		cs4270->slave_mode = 0;
301		break;
302	default:
303		/* all other modes are unsupported by the hardware */
304		dev_err(codec->dev, "Unknown master/slave configuration\n");
305		return -EINVAL;
306	}
307
308	return 0;
309}
310
311/**
312 * cs4270_hw_params - program the CS4270 with the given hardware parameters.
313 * @substream: the audio stream
314 * @params: the hardware parameters to set
315 * @dai: the SOC DAI (ignored)
316 *
317 * This function programs the hardware with the values provided.
318 * Specifically, the sample rate and the data format.
319 *
320 * The .ops functions are used to provide board-specific data, like input
321 * frequencies, to this driver.  This function takes that information,
322 * combines it with the hardware parameters provided, and programs the
323 * hardware accordingly.
324 */
325static int cs4270_hw_params(struct snd_pcm_substream *substream,
326			    struct snd_pcm_hw_params *params,
327			    struct snd_soc_dai *dai)
328{
329	struct snd_soc_codec *codec = dai->codec;
330	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
331	int ret;
332	unsigned int i;
333	unsigned int rate;
334	unsigned int ratio;
335	int reg;
336
337	/* Figure out which MCLK/LRCK ratio to use */
338
339	rate = params_rate(params);	/* Sampling rate, in Hz */
340	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
341
342	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
343		if (cs4270_mode_ratios[i].ratio == ratio)
344			break;
345	}
346
347	if (i == NUM_MCLK_RATIOS) {
348		/* We did not find a matching ratio */
349		dev_err(codec->dev, "could not find matching ratio\n");
350		return -EINVAL;
351	}
352
353	/* Set the sample rate */
354
355	reg = snd_soc_read(codec, CS4270_MODE);
356	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
357	reg |= cs4270_mode_ratios[i].mclk;
358
359	if (cs4270->slave_mode)
360		reg |= CS4270_MODE_SLAVE;
361	else
362		reg |= cs4270_mode_ratios[i].speed_mode;
363
364	ret = snd_soc_write(codec, CS4270_MODE, reg);
365	if (ret < 0) {
366		dev_err(codec->dev, "i2c write failed\n");
367		return ret;
368	}
369
370	/* Set the DAI format */
371
372	reg = snd_soc_read(codec, CS4270_FORMAT);
373	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
374
375	switch (cs4270->mode) {
376	case SND_SOC_DAIFMT_I2S:
377		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
378		break;
379	case SND_SOC_DAIFMT_LEFT_J:
380		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
381		break;
382	default:
383		dev_err(codec->dev, "unknown dai format\n");
384		return -EINVAL;
385	}
386
387	ret = snd_soc_write(codec, CS4270_FORMAT, reg);
388	if (ret < 0) {
389		dev_err(codec->dev, "i2c write failed\n");
390		return ret;
391	}
392
393	return ret;
394}
395
396/**
397 * cs4270_dai_mute - enable/disable the CS4270 external mute
398 * @dai: the SOC DAI
399 * @mute: 0 = disable mute, 1 = enable mute
400 *
401 * This function toggles the mute bits in the MUTE register.  The CS4270's
402 * mute capability is intended for external muting circuitry, so if the
403 * board does not have the MUTEA or MUTEB pins connected to such circuitry,
404 * then this function will do nothing.
405 */
406static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
407{
408	struct snd_soc_codec *codec = dai->codec;
409	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
410	int reg6;
411
412	reg6 = snd_soc_read(codec, CS4270_MUTE);
413
414	if (mute)
415		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
416	else {
417		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
418		reg6 |= cs4270->manual_mute;
419	}
420
421	return snd_soc_write(codec, CS4270_MUTE, reg6);
422}
423
424/**
425 * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
426 * 			 alsa control.
427 * @kcontrol: mixer control
428 * @ucontrol: control element information
429 *
430 * This function basically passes the arguments on to the generic
431 * snd_soc_put_volsw() function and saves the mute information in
432 * our private data structure. This is because we want to prevent
433 * cs4270_dai_mute() neglecting the user's decision to manually
434 * mute the codec's output.
435 *
436 * Returns 0 for success.
437 */
438static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
439				struct snd_ctl_elem_value *ucontrol)
440{
441	struct snd_soc_codec *codec = snd_soc_kcontrol_codec(kcontrol);
442	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
443	int left = !ucontrol->value.integer.value[0];
444	int right = !ucontrol->value.integer.value[1];
445
446	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
447			      (right ? CS4270_MUTE_DAC_B : 0);
448
449	return snd_soc_put_volsw(kcontrol, ucontrol);
450}
451
452/* A list of non-DAPM controls that the CS4270 supports */
453static const struct snd_kcontrol_new cs4270_snd_controls[] = {
454	SOC_DOUBLE_R("Master Playback Volume",
455		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
456	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
457	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
458	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
459	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
460	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
461	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
462	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
463	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
464		snd_soc_get_volsw, cs4270_soc_put_mute),
465};
466
467static const struct snd_soc_dai_ops cs4270_dai_ops = {
468	.hw_params	= cs4270_hw_params,
469	.set_sysclk	= cs4270_set_dai_sysclk,
470	.set_fmt	= cs4270_set_dai_fmt,
471	.digital_mute	= cs4270_dai_mute,
472};
473
474static struct snd_soc_dai_driver cs4270_dai = {
475	.name = "cs4270-hifi",
476	.playback = {
477		.stream_name = "Playback",
478		.channels_min = 2,
479		.channels_max = 2,
480		.rates = SNDRV_PCM_RATE_CONTINUOUS,
481		.rate_min = 4000,
482		.rate_max = 216000,
483		.formats = CS4270_FORMATS,
484	},
485	.capture = {
486		.stream_name = "Capture",
487		.channels_min = 2,
488		.channels_max = 2,
489		.rates = SNDRV_PCM_RATE_CONTINUOUS,
490		.rate_min = 4000,
491		.rate_max = 216000,
492		.formats = CS4270_FORMATS,
493	},
494	.ops = &cs4270_dai_ops,
495};
496
497/**
498 * cs4270_probe - ASoC probe function
499 * @pdev: platform device
500 *
501 * This function is called when ASoC has all the pieces it needs to
502 * instantiate a sound driver.
503 */
504static int cs4270_probe(struct snd_soc_codec *codec)
505{
506	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
507	int ret;
508
509	/* Disable auto-mute.  This feature appears to be buggy.  In some
510	 * situations, auto-mute will not deactivate when it should, so we want
511	 * this feature disabled by default.  An application (e.g. alsactl) can
512	 * re-enabled it by using the controls.
513	 */
514	ret = snd_soc_update_bits(codec, CS4270_MUTE, CS4270_MUTE_AUTO, 0);
515	if (ret < 0) {
516		dev_err(codec->dev, "i2c write failed\n");
517		return ret;
518	}
519
520	/* Disable automatic volume control.  The hardware enables, and it
521	 * causes volume change commands to be delayed, sometimes until after
522	 * playback has started.  An application (e.g. alsactl) can
523	 * re-enabled it by using the controls.
524	 */
525	ret = snd_soc_update_bits(codec, CS4270_TRANS,
526		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);
527	if (ret < 0) {
528		dev_err(codec->dev, "i2c write failed\n");
529		return ret;
530	}
531
532	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
533				    cs4270->supplies);
534
535	return ret;
536}
537
538/**
539 * cs4270_remove - ASoC remove function
540 * @pdev: platform device
541 *
542 * This function is the counterpart to cs4270_probe().
543 */
544static int cs4270_remove(struct snd_soc_codec *codec)
545{
546	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
547
548	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
549
550	return 0;
551};
552
553#ifdef CONFIG_PM
554
555/* This suspend/resume implementation can handle both - a simple standby
556 * where the codec remains powered, and a full suspend, where the voltage
557 * domain the codec is connected to is teared down and/or any other hardware
558 * reset condition is asserted.
559 *
560 * The codec's own power saving features are enabled in the suspend callback,
561 * and all registers are written back to the hardware when resuming.
562 */
563
564static int cs4270_soc_suspend(struct snd_soc_codec *codec)
565{
566	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
567	int reg, ret;
568
569	reg = snd_soc_read(codec, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
570	if (reg < 0)
571		return reg;
572
573	ret = snd_soc_write(codec, CS4270_PWRCTL, reg);
574	if (ret < 0)
575		return ret;
576
577	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
578			       cs4270->supplies);
579
580	return 0;
581}
582
583static int cs4270_soc_resume(struct snd_soc_codec *codec)
584{
585	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
586	int reg, ret;
587
588	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
589				    cs4270->supplies);
590	if (ret != 0)
591		return ret;
592
593	/* In case the device was put to hard reset during sleep, we need to
594	 * wait 500ns here before any I2C communication. */
595	ndelay(500);
596
597	/* first restore the entire register cache ... */
598	regcache_sync(cs4270->regmap);
599
600	/* ... then disable the power-down bits */
601	reg = snd_soc_read(codec, CS4270_PWRCTL);
602	reg &= ~CS4270_PWRCTL_PDN_ALL;
603
604	return snd_soc_write(codec, CS4270_PWRCTL, reg);
605}
606#else
607#define cs4270_soc_suspend	NULL
608#define cs4270_soc_resume	NULL
609#endif /* CONFIG_PM */
610
611/*
612 * ASoC codec driver structure
613 */
614static const struct snd_soc_codec_driver soc_codec_device_cs4270 = {
615	.probe =		cs4270_probe,
616	.remove =		cs4270_remove,
617	.suspend =		cs4270_soc_suspend,
618	.resume =		cs4270_soc_resume,
619
620	.controls =		cs4270_snd_controls,
621	.num_controls =		ARRAY_SIZE(cs4270_snd_controls),
622	.dapm_widgets =		cs4270_dapm_widgets,
623	.num_dapm_widgets =	ARRAY_SIZE(cs4270_dapm_widgets),
624	.dapm_routes =		cs4270_dapm_routes,
625	.num_dapm_routes =	ARRAY_SIZE(cs4270_dapm_routes),
626};
627
628/*
629 * cs4270_of_match - the device tree bindings
630 */
631static const struct of_device_id cs4270_of_match[] = {
632	{ .compatible = "cirrus,cs4270", },
633	{ }
634};
635MODULE_DEVICE_TABLE(of, cs4270_of_match);
636
637static const struct regmap_config cs4270_regmap = {
638	.reg_bits =		8,
639	.val_bits =		8,
640	.max_register =		CS4270_LASTREG,
641	.reg_defaults =		cs4270_reg_defaults,
642	.num_reg_defaults =	ARRAY_SIZE(cs4270_reg_defaults),
643	.cache_type =		REGCACHE_RBTREE,
644
645	.readable_reg =		cs4270_reg_is_readable,
646	.volatile_reg =		cs4270_reg_is_volatile,
647};
648
649/**
650 * cs4270_i2c_probe - initialize the I2C interface of the CS4270
651 * @i2c_client: the I2C client object
652 * @id: the I2C device ID (ignored)
653 *
654 * This function is called whenever the I2C subsystem finds a device that
655 * matches the device ID given via a prior call to i2c_add_driver().
656 */
657static int cs4270_i2c_probe(struct i2c_client *i2c_client,
658	const struct i2c_device_id *id)
659{
660	struct device_node *np = i2c_client->dev.of_node;
661	struct cs4270_private *cs4270;
662	unsigned int val;
663	int ret, i;
664
665	cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),
666			      GFP_KERNEL);
667	if (!cs4270)
668		return -ENOMEM;
669
670	/* get the power supply regulators */
671	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
672		cs4270->supplies[i].supply = supply_names[i];
673
674	ret = devm_regulator_bulk_get(&i2c_client->dev,
675				      ARRAY_SIZE(cs4270->supplies),
676				      cs4270->supplies);
677	if (ret < 0)
678		return ret;
679
680	/* See if we have a way to bring the codec out of reset */
681	if (np) {
682		enum of_gpio_flags flags;
683		int gpio = of_get_named_gpio_flags(np, "reset-gpio", 0, &flags);
684
685		if (gpio_is_valid(gpio)) {
686			ret = devm_gpio_request_one(&i2c_client->dev, gpio,
687				     flags & OF_GPIO_ACTIVE_LOW ?
688					GPIOF_OUT_INIT_LOW : GPIOF_OUT_INIT_HIGH,
689				     "cs4270 reset");
690			if (ret < 0)
691				return ret;
692		}
693	}
694
695	cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);
696	if (IS_ERR(cs4270->regmap))
697		return PTR_ERR(cs4270->regmap);
698
699	/* Verify that we have a CS4270 */
700	ret = regmap_read(cs4270->regmap, CS4270_CHIPID, &val);
701	if (ret < 0) {
702		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
703		       i2c_client->addr);
704		return ret;
705	}
706	/* The top four bits of the chip ID should be 1100. */
707	if ((val & 0xF0) != 0xC0) {
708		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
709		       i2c_client->addr);
710		return -ENODEV;
711	}
712
713	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
714		i2c_client->addr);
715	dev_info(&i2c_client->dev, "hardware revision %X\n", val & 0xF);
716
717	i2c_set_clientdata(i2c_client, cs4270);
718
719	ret = snd_soc_register_codec(&i2c_client->dev,
720			&soc_codec_device_cs4270, &cs4270_dai, 1);
721	return ret;
722}
723
724/**
725 * cs4270_i2c_remove - remove an I2C device
726 * @i2c_client: the I2C client object
727 *
728 * This function is the counterpart to cs4270_i2c_probe().
729 */
730static int cs4270_i2c_remove(struct i2c_client *i2c_client)
731{
732	snd_soc_unregister_codec(&i2c_client->dev);
733	return 0;
734}
735
736/*
737 * cs4270_id - I2C device IDs supported by this driver
738 */
739static const struct i2c_device_id cs4270_id[] = {
740	{"cs4270", 0},
741	{}
742};
743MODULE_DEVICE_TABLE(i2c, cs4270_id);
744
745/*
746 * cs4270_i2c_driver - I2C device identification
747 *
748 * This structure tells the I2C subsystem how to identify and support a
749 * given I2C device type.
750 */
751static struct i2c_driver cs4270_i2c_driver = {
752	.driver = {
753		.name = "cs4270",
754		.owner = THIS_MODULE,
755		.of_match_table = cs4270_of_match,
756	},
757	.id_table = cs4270_id,
758	.probe = cs4270_i2c_probe,
759	.remove = cs4270_i2c_remove,
760};
761
762module_i2c_driver(cs4270_i2c_driver);
763
764MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
765MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
766MODULE_LICENSE("GPL");
767