xref: /linux/sound/soc/codecs/cs4270.c (revision cbae17630954cb89f2bdf5bbadfd3aa81ea67283)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * CS4270 ALSA SoC (ASoC) codec driver
4  *
5  * Author: Timur Tabi <timur@freescale.com>
6  *
7  * Copyright 2007-2009 Freescale Semiconductor, Inc.
8  *
9  * This is an ASoC device driver for the Cirrus Logic CS4270 codec.
10  *
11  * Current features/limitations:
12  *
13  * - Software mode is supported.  Stand-alone mode is not supported.
14  * - Only I2C is supported, not SPI
15  * - Support for master and slave mode
16  * - The machine driver's 'startup' function must call
17  *   cs4270_set_dai_sysclk() with the value of MCLK.
18  * - Only I2S and left-justified modes are supported
19  * - Power management is supported
20  */
21 
22 #include <linux/module.h>
23 #include <linux/slab.h>
24 #include <sound/core.h>
25 #include <sound/soc.h>
26 #include <sound/initval.h>
27 #include <linux/i2c.h>
28 #include <linux/delay.h>
29 #include <linux/regulator/consumer.h>
30 #include <linux/gpio/consumer.h>
31 
32 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | SNDRV_PCM_FMTBIT_S16_LE  | \
33 			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S20_3LE | \
34 			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_LE)
35 
36 /* CS4270 registers addresses */
37 #define CS4270_CHIPID	0x01	/* Chip ID */
38 #define CS4270_PWRCTL	0x02	/* Power Control */
39 #define CS4270_MODE	0x03	/* Mode Control */
40 #define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
41 #define CS4270_TRANS	0x05	/* Transition Control */
42 #define CS4270_MUTE	0x06	/* Mute Control */
43 #define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
44 #define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
45 
46 #define CS4270_FIRSTREG	0x01
47 #define CS4270_LASTREG	0x08
48 #define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
49 #define CS4270_I2C_INCR	0x80
50 
51 /* Bit masks for the CS4270 registers */
52 #define CS4270_CHIPID_ID	0xF0
53 #define CS4270_CHIPID_REV	0x0F
54 #define CS4270_PWRCTL_FREEZE	0x80
55 #define CS4270_PWRCTL_PDN_ADC	0x20
56 #define CS4270_PWRCTL_PDN_DAC	0x02
57 #define CS4270_PWRCTL_PDN	0x01
58 #define CS4270_PWRCTL_PDN_ALL	\
59 	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
60 #define CS4270_MODE_SPEED_MASK	0x30
61 #define CS4270_MODE_1X		0x00
62 #define CS4270_MODE_2X		0x10
63 #define CS4270_MODE_4X		0x20
64 #define CS4270_MODE_SLAVE	0x30
65 #define CS4270_MODE_DIV_MASK	0x0E
66 #define CS4270_MODE_DIV1	0x00
67 #define CS4270_MODE_DIV15	0x02
68 #define CS4270_MODE_DIV2	0x04
69 #define CS4270_MODE_DIV3	0x06
70 #define CS4270_MODE_DIV4	0x08
71 #define CS4270_MODE_POPGUARD	0x01
72 #define CS4270_FORMAT_FREEZE_A	0x80
73 #define CS4270_FORMAT_FREEZE_B	0x40
74 #define CS4270_FORMAT_LOOPBACK	0x20
75 #define CS4270_FORMAT_DAC_MASK	0x18
76 #define CS4270_FORMAT_DAC_LJ	0x00
77 #define CS4270_FORMAT_DAC_I2S	0x08
78 #define CS4270_FORMAT_DAC_RJ16	0x18
79 #define CS4270_FORMAT_DAC_RJ24	0x10
80 #define CS4270_FORMAT_ADC_MASK	0x01
81 #define CS4270_FORMAT_ADC_LJ	0x00
82 #define CS4270_FORMAT_ADC_I2S	0x01
83 #define CS4270_TRANS_ONE_VOL	0x80
84 #define CS4270_TRANS_SOFT	0x40
85 #define CS4270_TRANS_ZERO	0x20
86 #define CS4270_TRANS_INV_ADC_A	0x08
87 #define CS4270_TRANS_INV_ADC_B	0x10
88 #define CS4270_TRANS_INV_DAC_A	0x02
89 #define CS4270_TRANS_INV_DAC_B	0x04
90 #define CS4270_TRANS_DEEMPH	0x01
91 #define CS4270_MUTE_AUTO	0x20
92 #define CS4270_MUTE_ADC_A	0x08
93 #define CS4270_MUTE_ADC_B	0x10
94 #define CS4270_MUTE_POLARITY	0x04
95 #define CS4270_MUTE_DAC_A	0x01
96 #define CS4270_MUTE_DAC_B	0x02
97 
98 /* Power-on default values for the registers
99  *
100  * This array contains the power-on default values of the registers, with the
101  * exception of the "CHIPID" register (01h).  The lower four bits of that
102  * register contain the hardware revision, so it is treated as volatile.
103  */
104 static const struct reg_default cs4270_reg_defaults[] = {
105 	{ 2, 0x00 },
106 	{ 3, 0x30 },
107 	{ 4, 0x00 },
108 	{ 5, 0x60 },
109 	{ 6, 0x20 },
110 	{ 7, 0x00 },
111 	{ 8, 0x00 },
112 };
113 
114 static const char *supply_names[] = {
115 	"va", "vd", "vlc"
116 };
117 
118 /* Private data for the CS4270 */
119 struct cs4270_private {
120 	struct regmap *regmap;
121 	unsigned int mclk; /* Input frequency of the MCLK pin */
122 	unsigned int mode; /* The mode (I2S or left-justified) */
123 	unsigned int slave_mode;
124 	unsigned int manual_mute;
125 
126 	/* power domain regulators */
127 	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
128 
129 	/* reset gpio */
130 	struct gpio_desc *reset_gpio;
131 };
132 
133 static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {
134 SND_SOC_DAPM_INPUT("AINL"),
135 SND_SOC_DAPM_INPUT("AINR"),
136 
137 SND_SOC_DAPM_OUTPUT("AOUTL"),
138 SND_SOC_DAPM_OUTPUT("AOUTR"),
139 };
140 
141 static const struct snd_soc_dapm_route cs4270_dapm_routes[] = {
142 	{ "Capture", NULL, "AINL" },
143 	{ "Capture", NULL, "AINR" },
144 
145 	{ "AOUTL", NULL, "Playback" },
146 	{ "AOUTR", NULL, "Playback" },
147 };
148 
149 /**
150  * struct cs4270_mode_ratios - clock ratio tables
151  * @ratio: the ratio of MCLK to the sample rate
152  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
153  *              this ratio
154  * @mclk: the Ratio Select bits to set in the Mode Control register for this
155  *        ratio
156  *
157  * The data for this chart is taken from Table 5 of the CS4270 reference
158  * manual.
159  *
160  * This table is used to determine how to program the Mode Control register.
161  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
162  * rates the CS4270 currently supports.
163  *
164  * @speed_mode is the corresponding bit pattern to be written to the
165  * MODE bits of the Mode Control Register
166  *
167  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
168  * the Mode Control Register.
169  *
170  * In situations where a single ratio is represented by multiple speed
171  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
172  * double-speed instead of quad-speed.  However, the CS4270 errata states
173  * that divide-By-1.5 can cause failures, so we avoid that mode where
174  * possible.
175  *
176  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
177  * work if Vd is 3.3V.  If this effects you, select the
178  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
179  * never select any sample rates that require divide-by-1.5.
180  */
181 struct cs4270_mode_ratios {
182 	unsigned int ratio;
183 	u8 speed_mode;
184 	u8 mclk;
185 };
186 
187 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
188 	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
189 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
190 	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
191 #endif
192 	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
193 	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
194 	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
195 	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
196 	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
197 	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
198 	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
199 };
200 
201 /* The number of MCLK/LRCK ratios supported by the CS4270 */
202 #define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
203 
204 static bool cs4270_reg_is_readable(struct device *dev, unsigned int reg)
205 {
206 	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);
207 }
208 
209 static bool cs4270_reg_is_volatile(struct device *dev, unsigned int reg)
210 {
211 	/* Unreadable registers are considered volatile */
212 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
213 		return true;
214 
215 	return reg == CS4270_CHIPID;
216 }
217 
218 /**
219  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
220  * @codec_dai: the codec DAI
221  * @clk_id: the clock ID (ignored)
222  * @freq: the MCLK input frequency
223  * @dir: the clock direction (ignored)
224  *
225  * This function is used to tell the codec driver what the input MCLK
226  * frequency is.
227  *
228  * The value of MCLK is used to determine which sample rates are supported
229  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
230  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
231  *
232  * This function calculates the nine ratios and determines which ones match
233  * a standard sample rate.  If there's a match, then it is added to the list
234  * of supported sample rates.
235  *
236  * This function must be called by the machine driver's 'startup' function,
237  * otherwise the list of supported sample rates will not be available in
238  * time for ALSA.
239  *
240  * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
241  * theoretically possible sample rates to be enabled. Call it again with a
242  * proper value set one the external clock is set (most probably you would do
243  * that from a machine's driver 'hw_param' hook.
244  */
245 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
246 				 int clk_id, unsigned int freq, int dir)
247 {
248 	struct snd_soc_component *component = codec_dai->component;
249 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
250 
251 	cs4270->mclk = freq;
252 	return 0;
253 }
254 
255 /**
256  * cs4270_set_dai_fmt - configure the codec for the selected audio format
257  * @codec_dai: the codec DAI
258  * @format: a SND_SOC_DAIFMT_x value indicating the data format
259  *
260  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
261  * codec accordingly.
262  *
263  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
264  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
265  * data for playback only, but ASoC currently does not support different
266  * formats for playback vs. record.
267  */
268 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
269 			      unsigned int format)
270 {
271 	struct snd_soc_component *component = codec_dai->component;
272 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
273 
274 	/* set DAI format */
275 	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
276 	case SND_SOC_DAIFMT_I2S:
277 	case SND_SOC_DAIFMT_LEFT_J:
278 		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
279 		break;
280 	default:
281 		dev_err(component->dev, "invalid dai format\n");
282 		return -EINVAL;
283 	}
284 
285 	/* set master/slave audio interface */
286 	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
287 	case SND_SOC_DAIFMT_CBC_CFC:
288 		cs4270->slave_mode = 1;
289 		break;
290 	case SND_SOC_DAIFMT_CBP_CFP:
291 		cs4270->slave_mode = 0;
292 		break;
293 	default:
294 		/* all other modes are unsupported by the hardware */
295 		dev_err(component->dev, "Unknown master/slave configuration\n");
296 		return -EINVAL;
297 	}
298 
299 	return 0;
300 }
301 
302 /**
303  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
304  * @substream: the audio stream
305  * @params: the hardware parameters to set
306  * @dai: the SOC DAI (ignored)
307  *
308  * This function programs the hardware with the values provided.
309  * Specifically, the sample rate and the data format.
310  *
311  * The .ops functions are used to provide board-specific data, like input
312  * frequencies, to this driver.  This function takes that information,
313  * combines it with the hardware parameters provided, and programs the
314  * hardware accordingly.
315  */
316 static int cs4270_hw_params(struct snd_pcm_substream *substream,
317 			    struct snd_pcm_hw_params *params,
318 			    struct snd_soc_dai *dai)
319 {
320 	struct snd_soc_component *component = dai->component;
321 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
322 	int ret;
323 	unsigned int i;
324 	unsigned int rate;
325 	unsigned int ratio;
326 	int reg;
327 
328 	/* Figure out which MCLK/LRCK ratio to use */
329 
330 	rate = params_rate(params);	/* Sampling rate, in Hz */
331 	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
332 
333 	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
334 		if (cs4270_mode_ratios[i].ratio == ratio)
335 			break;
336 	}
337 
338 	if (i == NUM_MCLK_RATIOS) {
339 		/* We did not find a matching ratio */
340 		dev_err(component->dev, "could not find matching ratio\n");
341 		return -EINVAL;
342 	}
343 
344 	/* Set the sample rate */
345 
346 	reg = snd_soc_component_read(component, CS4270_MODE);
347 	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
348 	reg |= cs4270_mode_ratios[i].mclk;
349 
350 	if (cs4270->slave_mode)
351 		reg |= CS4270_MODE_SLAVE;
352 	else
353 		reg |= cs4270_mode_ratios[i].speed_mode;
354 
355 	ret = snd_soc_component_write(component, CS4270_MODE, reg);
356 	if (ret < 0) {
357 		dev_err(component->dev, "i2c write failed\n");
358 		return ret;
359 	}
360 
361 	/* Set the DAI format */
362 
363 	reg = snd_soc_component_read(component, CS4270_FORMAT);
364 	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
365 
366 	switch (cs4270->mode) {
367 	case SND_SOC_DAIFMT_I2S:
368 		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
369 		break;
370 	case SND_SOC_DAIFMT_LEFT_J:
371 		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
372 		break;
373 	default:
374 		dev_err(component->dev, "unknown dai format\n");
375 		return -EINVAL;
376 	}
377 
378 	ret = snd_soc_component_write(component, CS4270_FORMAT, reg);
379 	if (ret < 0) {
380 		dev_err(component->dev, "i2c write failed\n");
381 		return ret;
382 	}
383 
384 	return ret;
385 }
386 
387 /**
388  * cs4270_dai_mute - enable/disable the CS4270 external mute
389  * @dai: the SOC DAI
390  * @mute: 0 = disable mute, 1 = enable mute
391  * @direction: (ignored)
392  *
393  * This function toggles the mute bits in the MUTE register.  The CS4270's
394  * mute capability is intended for external muting circuitry, so if the
395  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
396  * then this function will do nothing.
397  */
398 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute, int direction)
399 {
400 	struct snd_soc_component *component = dai->component;
401 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
402 	int reg6;
403 
404 	reg6 = snd_soc_component_read(component, CS4270_MUTE);
405 
406 	if (mute)
407 		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
408 	else {
409 		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
410 		reg6 |= cs4270->manual_mute;
411 	}
412 
413 	return snd_soc_component_write(component, CS4270_MUTE, reg6);
414 }
415 
416 /**
417  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
418  * 			 alsa control.
419  * @kcontrol: mixer control
420  * @ucontrol: control element information
421  *
422  * This function basically passes the arguments on to the generic
423  * snd_soc_put_volsw() function and saves the mute information in
424  * our private data structure. This is because we want to prevent
425  * cs4270_dai_mute() neglecting the user's decision to manually
426  * mute the codec's output.
427  *
428  * Returns 0 for success.
429  */
430 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
431 				struct snd_ctl_elem_value *ucontrol)
432 {
433 	struct snd_soc_component *component = snd_kcontrol_chip(kcontrol);
434 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
435 	int left = !ucontrol->value.integer.value[0];
436 	int right = !ucontrol->value.integer.value[1];
437 
438 	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
439 			      (right ? CS4270_MUTE_DAC_B : 0);
440 
441 	return snd_soc_put_volsw(kcontrol, ucontrol);
442 }
443 
444 /* A list of non-DAPM controls that the CS4270 supports */
445 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
446 	SOC_DOUBLE_R("Master Playback Volume",
447 		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
448 	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
449 	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
450 	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
451 	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
452 	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
453 	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
454 	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
455 	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
456 		snd_soc_get_volsw, cs4270_soc_put_mute),
457 };
458 
459 static const struct snd_soc_dai_ops cs4270_dai_ops = {
460 	.hw_params	= cs4270_hw_params,
461 	.set_sysclk	= cs4270_set_dai_sysclk,
462 	.set_fmt	= cs4270_set_dai_fmt,
463 	.mute_stream	= cs4270_dai_mute,
464 	.no_capture_mute = 1,
465 };
466 
467 static struct snd_soc_dai_driver cs4270_dai = {
468 	.name = "cs4270-hifi",
469 	.playback = {
470 		.stream_name = "Playback",
471 		.channels_min = 2,
472 		.channels_max = 2,
473 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
474 		.rate_min = 4000,
475 		.rate_max = 216000,
476 		.formats = CS4270_FORMATS,
477 	},
478 	.capture = {
479 		.stream_name = "Capture",
480 		.channels_min = 2,
481 		.channels_max = 2,
482 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
483 		.rate_min = 4000,
484 		.rate_max = 216000,
485 		.formats = CS4270_FORMATS,
486 	},
487 	.ops = &cs4270_dai_ops,
488 };
489 
490 /**
491  * cs4270_probe - ASoC probe function
492  * @component: ASoC component
493  *
494  * This function is called when ASoC has all the pieces it needs to
495  * instantiate a sound driver.
496  */
497 static int cs4270_probe(struct snd_soc_component *component)
498 {
499 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
500 	int ret;
501 
502 	/* Disable auto-mute.  This feature appears to be buggy.  In some
503 	 * situations, auto-mute will not deactivate when it should, so we want
504 	 * this feature disabled by default.  An application (e.g. alsactl) can
505 	 * re-enabled it by using the controls.
506 	 */
507 	ret = snd_soc_component_update_bits(component, CS4270_MUTE, CS4270_MUTE_AUTO, 0);
508 	if (ret < 0) {
509 		dev_err(component->dev, "i2c write failed\n");
510 		return ret;
511 	}
512 
513 	/* Disable automatic volume control.  The hardware enables, and it
514 	 * causes volume change commands to be delayed, sometimes until after
515 	 * playback has started.  An application (e.g. alsactl) can
516 	 * re-enabled it by using the controls.
517 	 */
518 	ret = snd_soc_component_update_bits(component, CS4270_TRANS,
519 		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);
520 	if (ret < 0) {
521 		dev_err(component->dev, "i2c write failed\n");
522 		return ret;
523 	}
524 
525 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
526 				    cs4270->supplies);
527 
528 	return ret;
529 }
530 
531 /**
532  * cs4270_remove - ASoC remove function
533  * @component: ASoC component
534  *
535  * This function is the counterpart to cs4270_probe().
536  */
537 static void cs4270_remove(struct snd_soc_component *component)
538 {
539 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
540 
541 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
542 };
543 
544 #ifdef CONFIG_PM
545 
546 /* This suspend/resume implementation can handle both - a simple standby
547  * where the codec remains powered, and a full suspend, where the voltage
548  * domain the codec is connected to is teared down and/or any other hardware
549  * reset condition is asserted.
550  *
551  * The codec's own power saving features are enabled in the suspend callback,
552  * and all registers are written back to the hardware when resuming.
553  */
554 
555 static int cs4270_soc_suspend(struct snd_soc_component *component)
556 {
557 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
558 	int reg, ret;
559 
560 	reg = snd_soc_component_read(component, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
561 	if (reg < 0)
562 		return reg;
563 
564 	ret = snd_soc_component_write(component, CS4270_PWRCTL, reg);
565 	if (ret < 0)
566 		return ret;
567 
568 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
569 			       cs4270->supplies);
570 
571 	return 0;
572 }
573 
574 static int cs4270_soc_resume(struct snd_soc_component *component)
575 {
576 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
577 	int reg, ret;
578 
579 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
580 				    cs4270->supplies);
581 	if (ret != 0)
582 		return ret;
583 
584 	/* In case the device was put to hard reset during sleep, we need to
585 	 * wait 500ns here before any I2C communication. */
586 	ndelay(500);
587 
588 	/* first restore the entire register cache ... */
589 	regcache_sync(cs4270->regmap);
590 
591 	/* ... then disable the power-down bits */
592 	reg = snd_soc_component_read(component, CS4270_PWRCTL);
593 	reg &= ~CS4270_PWRCTL_PDN_ALL;
594 
595 	return snd_soc_component_write(component, CS4270_PWRCTL, reg);
596 }
597 #else
598 #define cs4270_soc_suspend	NULL
599 #define cs4270_soc_resume	NULL
600 #endif /* CONFIG_PM */
601 
602 /*
603  * ASoC codec driver structure
604  */
605 static const struct snd_soc_component_driver soc_component_device_cs4270 = {
606 	.probe			= cs4270_probe,
607 	.remove			= cs4270_remove,
608 	.suspend		= cs4270_soc_suspend,
609 	.resume			= cs4270_soc_resume,
610 	.controls		= cs4270_snd_controls,
611 	.num_controls		= ARRAY_SIZE(cs4270_snd_controls),
612 	.dapm_widgets		= cs4270_dapm_widgets,
613 	.num_dapm_widgets	= ARRAY_SIZE(cs4270_dapm_widgets),
614 	.dapm_routes		= cs4270_dapm_routes,
615 	.num_dapm_routes	= ARRAY_SIZE(cs4270_dapm_routes),
616 	.idle_bias_on		= 1,
617 	.use_pmdown_time	= 1,
618 	.endianness		= 1,
619 };
620 
621 /*
622  * cs4270_of_match - the device tree bindings
623  */
624 static const struct of_device_id cs4270_of_match[] = {
625 	{ .compatible = "cirrus,cs4270", },
626 	{ }
627 };
628 MODULE_DEVICE_TABLE(of, cs4270_of_match);
629 
630 static const struct regmap_config cs4270_regmap = {
631 	.reg_bits =		8,
632 	.val_bits =		8,
633 	.max_register =		CS4270_LASTREG,
634 	.reg_defaults =		cs4270_reg_defaults,
635 	.num_reg_defaults =	ARRAY_SIZE(cs4270_reg_defaults),
636 	.cache_type =		REGCACHE_MAPLE,
637 	.write_flag_mask =	CS4270_I2C_INCR,
638 
639 	.readable_reg =		cs4270_reg_is_readable,
640 	.volatile_reg =		cs4270_reg_is_volatile,
641 };
642 
643 /**
644  * cs4270_i2c_remove - deinitialize the I2C interface of the CS4270
645  * @i2c_client: the I2C client object
646  *
647  * This function puts the chip into low power mode when the i2c device
648  * is removed.
649  */
650 static void cs4270_i2c_remove(struct i2c_client *i2c_client)
651 {
652 	struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client);
653 
654 	gpiod_set_value_cansleep(cs4270->reset_gpio, 0);
655 }
656 
657 /**
658  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
659  * @i2c_client: the I2C client object
660  *
661  * This function is called whenever the I2C subsystem finds a device that
662  * matches the device ID given via a prior call to i2c_add_driver().
663  */
664 static int cs4270_i2c_probe(struct i2c_client *i2c_client)
665 {
666 	struct cs4270_private *cs4270;
667 	unsigned int val;
668 	int ret, i;
669 
670 	cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),
671 			      GFP_KERNEL);
672 	if (!cs4270)
673 		return -ENOMEM;
674 
675 	/* get the power supply regulators */
676 	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
677 		cs4270->supplies[i].supply = supply_names[i];
678 
679 	ret = devm_regulator_bulk_get(&i2c_client->dev,
680 				      ARRAY_SIZE(cs4270->supplies),
681 				      cs4270->supplies);
682 	if (ret < 0)
683 		return ret;
684 
685 	/* reset the device */
686 	cs4270->reset_gpio = devm_gpiod_get_optional(&i2c_client->dev, "reset",
687 						     GPIOD_OUT_LOW);
688 	if (IS_ERR(cs4270->reset_gpio)) {
689 		dev_dbg(&i2c_client->dev, "Error getting CS4270 reset GPIO\n");
690 		return PTR_ERR(cs4270->reset_gpio);
691 	}
692 
693 	if (cs4270->reset_gpio) {
694 		dev_dbg(&i2c_client->dev, "Found reset GPIO\n");
695 		gpiod_set_value_cansleep(cs4270->reset_gpio, 1);
696 	}
697 
698 	/* Sleep 500ns before i2c communications */
699 	ndelay(500);
700 
701 	cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);
702 	if (IS_ERR(cs4270->regmap))
703 		return PTR_ERR(cs4270->regmap);
704 
705 	/* Verify that we have a CS4270 */
706 	ret = regmap_read(cs4270->regmap, CS4270_CHIPID, &val);
707 	if (ret < 0) {
708 		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
709 		       i2c_client->addr);
710 		return ret;
711 	}
712 	/* The top four bits of the chip ID should be 1100. */
713 	if ((val & 0xF0) != 0xC0) {
714 		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
715 		       i2c_client->addr);
716 		return -ENODEV;
717 	}
718 
719 	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
720 		i2c_client->addr);
721 	dev_info(&i2c_client->dev, "hardware revision %X\n", val & 0xF);
722 
723 	i2c_set_clientdata(i2c_client, cs4270);
724 
725 	ret = devm_snd_soc_register_component(&i2c_client->dev,
726 			&soc_component_device_cs4270, &cs4270_dai, 1);
727 	return ret;
728 }
729 
730 /*
731  * cs4270_id - I2C device IDs supported by this driver
732  */
733 static const struct i2c_device_id cs4270_id[] = {
734 	{ .name = "cs4270" },
735 	{ }
736 };
737 MODULE_DEVICE_TABLE(i2c, cs4270_id);
738 
739 /*
740  * cs4270_i2c_driver - I2C device identification
741  *
742  * This structure tells the I2C subsystem how to identify and support a
743  * given I2C device type.
744  */
745 static struct i2c_driver cs4270_i2c_driver = {
746 	.driver = {
747 		.name = "cs4270",
748 		.of_match_table = cs4270_of_match,
749 	},
750 	.id_table = cs4270_id,
751 	.probe = cs4270_i2c_probe,
752 	.remove = cs4270_i2c_remove,
753 };
754 
755 module_i2c_driver(cs4270_i2c_driver);
756 
757 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
758 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
759 MODULE_LICENSE("GPL");
760