xref: /linux/sound/soc/codecs/cs4270.c (revision 23c996fc2bc1978a02c64eddb90b4ab5d309c8df)
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/mod_devicetable.h>
25 #include <linux/module.h>
26 #include <linux/slab.h>
27 #include <sound/core.h>
28 #include <sound/soc.h>
29 #include <sound/initval.h>
30 #include <linux/i2c.h>
31 #include <linux/delay.h>
32 #include <linux/regulator/consumer.h>
33 #include <linux/gpio/consumer.h>
34 
35 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | SNDRV_PCM_FMTBIT_S16_LE  | \
36 			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S20_3LE | \
37 			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_LE)
38 
39 /* CS4270 registers addresses */
40 #define CS4270_CHIPID	0x01	/* Chip ID */
41 #define CS4270_PWRCTL	0x02	/* Power Control */
42 #define CS4270_MODE	0x03	/* Mode Control */
43 #define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
44 #define CS4270_TRANS	0x05	/* Transition Control */
45 #define CS4270_MUTE	0x06	/* Mute Control */
46 #define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
47 #define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
48 
49 #define CS4270_FIRSTREG	0x01
50 #define CS4270_LASTREG	0x08
51 #define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
52 #define CS4270_I2C_INCR	0x80
53 
54 /* Bit masks for the CS4270 registers */
55 #define CS4270_CHIPID_ID	0xF0
56 #define CS4270_CHIPID_REV	0x0F
57 #define CS4270_PWRCTL_FREEZE	0x80
58 #define CS4270_PWRCTL_PDN_ADC	0x20
59 #define CS4270_PWRCTL_PDN_DAC	0x02
60 #define CS4270_PWRCTL_PDN	0x01
61 #define CS4270_PWRCTL_PDN_ALL	\
62 	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
63 #define CS4270_MODE_SPEED_MASK	0x30
64 #define CS4270_MODE_1X		0x00
65 #define CS4270_MODE_2X		0x10
66 #define CS4270_MODE_4X		0x20
67 #define CS4270_MODE_SLAVE	0x30
68 #define CS4270_MODE_DIV_MASK	0x0E
69 #define CS4270_MODE_DIV1	0x00
70 #define CS4270_MODE_DIV15	0x02
71 #define CS4270_MODE_DIV2	0x04
72 #define CS4270_MODE_DIV3	0x06
73 #define CS4270_MODE_DIV4	0x08
74 #define CS4270_MODE_POPGUARD	0x01
75 #define CS4270_FORMAT_FREEZE_A	0x80
76 #define CS4270_FORMAT_FREEZE_B	0x40
77 #define CS4270_FORMAT_LOOPBACK	0x20
78 #define CS4270_FORMAT_DAC_MASK	0x18
79 #define CS4270_FORMAT_DAC_LJ	0x00
80 #define CS4270_FORMAT_DAC_I2S	0x08
81 #define CS4270_FORMAT_DAC_RJ16	0x18
82 #define CS4270_FORMAT_DAC_RJ24	0x10
83 #define CS4270_FORMAT_ADC_MASK	0x01
84 #define CS4270_FORMAT_ADC_LJ	0x00
85 #define CS4270_FORMAT_ADC_I2S	0x01
86 #define CS4270_TRANS_ONE_VOL	0x80
87 #define CS4270_TRANS_SOFT	0x40
88 #define CS4270_TRANS_ZERO	0x20
89 #define CS4270_TRANS_INV_ADC_A	0x08
90 #define CS4270_TRANS_INV_ADC_B	0x10
91 #define CS4270_TRANS_INV_DAC_A	0x02
92 #define CS4270_TRANS_INV_DAC_B	0x04
93 #define CS4270_TRANS_DEEMPH	0x01
94 #define CS4270_MUTE_AUTO	0x20
95 #define CS4270_MUTE_ADC_A	0x08
96 #define CS4270_MUTE_ADC_B	0x10
97 #define CS4270_MUTE_POLARITY	0x04
98 #define CS4270_MUTE_DAC_A	0x01
99 #define CS4270_MUTE_DAC_B	0x02
100 
101 /* Power-on default values for the registers
102  *
103  * This array contains the power-on default values of the registers, with the
104  * exception of the "CHIPID" register (01h).  The lower four bits of that
105  * register contain the hardware revision, so it is treated as volatile.
106  */
107 static const struct reg_default cs4270_reg_defaults[] = {
108 	{ 2, 0x00 },
109 	{ 3, 0x30 },
110 	{ 4, 0x00 },
111 	{ 5, 0x60 },
112 	{ 6, 0x20 },
113 	{ 7, 0x00 },
114 	{ 8, 0x00 },
115 };
116 
117 static const char *supply_names[] = {
118 	"va", "vd", "vlc"
119 };
120 
121 /* Private data for the CS4270 */
122 struct cs4270_private {
123 	struct regmap *regmap;
124 	unsigned int mclk; /* Input frequency of the MCLK pin */
125 	unsigned int mode; /* The mode (I2S or left-justified) */
126 	unsigned int slave_mode;
127 	unsigned int manual_mute;
128 
129 	/* power domain regulators */
130 	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
131 
132 	/* reset gpio */
133 	struct gpio_desc *reset_gpio;
134 };
135 
136 static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {
137 SND_SOC_DAPM_INPUT("AINL"),
138 SND_SOC_DAPM_INPUT("AINR"),
139 
140 SND_SOC_DAPM_OUTPUT("AOUTL"),
141 SND_SOC_DAPM_OUTPUT("AOUTR"),
142 };
143 
144 static const struct snd_soc_dapm_route cs4270_dapm_routes[] = {
145 	{ "Capture", NULL, "AINL" },
146 	{ "Capture", NULL, "AINR" },
147 
148 	{ "AOUTL", NULL, "Playback" },
149 	{ "AOUTR", NULL, "Playback" },
150 };
151 
152 /**
153  * struct cs4270_mode_ratios - clock ratio tables
154  * @ratio: the ratio of MCLK to the sample rate
155  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
156  *              this ratio
157  * @mclk: the Ratio Select bits to set in the Mode Control register for this
158  *        ratio
159  *
160  * The data for this chart is taken from Table 5 of the CS4270 reference
161  * manual.
162  *
163  * This table is used to determine how to program the Mode Control register.
164  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
165  * rates the CS4270 currently supports.
166  *
167  * @speed_mode is the corresponding bit pattern to be written to the
168  * MODE bits of the Mode Control Register
169  *
170  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
171  * the Mode Control Register.
172  *
173  * In situations where a single ratio is represented by multiple speed
174  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
175  * double-speed instead of quad-speed.  However, the CS4270 errata states
176  * that divide-By-1.5 can cause failures, so we avoid that mode where
177  * possible.
178  *
179  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
180  * work if Vd is 3.3V.  If this effects you, select the
181  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
182  * never select any sample rates that require divide-by-1.5.
183  */
184 struct cs4270_mode_ratios {
185 	unsigned int ratio;
186 	u8 speed_mode;
187 	u8 mclk;
188 };
189 
190 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
191 	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
192 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
193 	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
194 #endif
195 	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
196 	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
197 	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
198 	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
199 	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
200 	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
201 	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
202 };
203 
204 /* The number of MCLK/LRCK ratios supported by the CS4270 */
205 #define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
206 
207 static bool cs4270_reg_is_readable(struct device *dev, unsigned int reg)
208 {
209 	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);
210 }
211 
212 static bool cs4270_reg_is_volatile(struct device *dev, unsigned int reg)
213 {
214 	/* Unreadable registers are considered volatile */
215 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
216 		return true;
217 
218 	return reg == CS4270_CHIPID;
219 }
220 
221 /**
222  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
223  * @codec_dai: the codec DAI
224  * @clk_id: the clock ID (ignored)
225  * @freq: the MCLK input frequency
226  * @dir: the clock direction (ignored)
227  *
228  * This function is used to tell the codec driver what the input MCLK
229  * frequency is.
230  *
231  * The value of MCLK is used to determine which sample rates are supported
232  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
233  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
234  *
235  * This function calculates the nine ratios and determines which ones match
236  * a standard sample rate.  If there's a match, then it is added to the list
237  * of supported sample rates.
238  *
239  * This function must be called by the machine driver's 'startup' function,
240  * otherwise the list of supported sample rates will not be available in
241  * time for ALSA.
242  *
243  * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
244  * theoretically possible sample rates to be enabled. Call it again with a
245  * proper value set one the external clock is set (most probably you would do
246  * that from a machine's driver 'hw_param' hook.
247  */
248 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
249 				 int clk_id, unsigned int freq, int dir)
250 {
251 	struct snd_soc_component *component = codec_dai->component;
252 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
253 
254 	cs4270->mclk = freq;
255 	return 0;
256 }
257 
258 /**
259  * cs4270_set_dai_fmt - configure the codec for the selected audio format
260  * @codec_dai: the codec DAI
261  * @format: a SND_SOC_DAIFMT_x value indicating the data format
262  *
263  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
264  * codec accordingly.
265  *
266  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
267  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
268  * data for playback only, but ASoC currently does not support different
269  * formats for playback vs. record.
270  */
271 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
272 			      unsigned int format)
273 {
274 	struct snd_soc_component *component = codec_dai->component;
275 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
276 
277 	/* set DAI format */
278 	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
279 	case SND_SOC_DAIFMT_I2S:
280 	case SND_SOC_DAIFMT_LEFT_J:
281 		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
282 		break;
283 	default:
284 		dev_err(component->dev, "invalid dai format\n");
285 		return -EINVAL;
286 	}
287 
288 	/* set master/slave audio interface */
289 	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
290 	case SND_SOC_DAIFMT_CBS_CFS:
291 		cs4270->slave_mode = 1;
292 		break;
293 	case SND_SOC_DAIFMT_CBM_CFM:
294 		cs4270->slave_mode = 0;
295 		break;
296 	default:
297 		/* all other modes are unsupported by the hardware */
298 		dev_err(component->dev, "Unknown master/slave configuration\n");
299 		return -EINVAL;
300 	}
301 
302 	return 0;
303 }
304 
305 /**
306  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
307  * @substream: the audio stream
308  * @params: the hardware parameters to set
309  * @dai: the SOC DAI (ignored)
310  *
311  * This function programs the hardware with the values provided.
312  * Specifically, the sample rate and the data format.
313  *
314  * The .ops functions are used to provide board-specific data, like input
315  * frequencies, to this driver.  This function takes that information,
316  * combines it with the hardware parameters provided, and programs the
317  * hardware accordingly.
318  */
319 static int cs4270_hw_params(struct snd_pcm_substream *substream,
320 			    struct snd_pcm_hw_params *params,
321 			    struct snd_soc_dai *dai)
322 {
323 	struct snd_soc_component *component = dai->component;
324 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
325 	int ret;
326 	unsigned int i;
327 	unsigned int rate;
328 	unsigned int ratio;
329 	int reg;
330 
331 	/* Figure out which MCLK/LRCK ratio to use */
332 
333 	rate = params_rate(params);	/* Sampling rate, in Hz */
334 	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
335 
336 	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
337 		if (cs4270_mode_ratios[i].ratio == ratio)
338 			break;
339 	}
340 
341 	if (i == NUM_MCLK_RATIOS) {
342 		/* We did not find a matching ratio */
343 		dev_err(component->dev, "could not find matching ratio\n");
344 		return -EINVAL;
345 	}
346 
347 	/* Set the sample rate */
348 
349 	reg = snd_soc_component_read(component, CS4270_MODE);
350 	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
351 	reg |= cs4270_mode_ratios[i].mclk;
352 
353 	if (cs4270->slave_mode)
354 		reg |= CS4270_MODE_SLAVE;
355 	else
356 		reg |= cs4270_mode_ratios[i].speed_mode;
357 
358 	ret = snd_soc_component_write(component, CS4270_MODE, reg);
359 	if (ret < 0) {
360 		dev_err(component->dev, "i2c write failed\n");
361 		return ret;
362 	}
363 
364 	/* Set the DAI format */
365 
366 	reg = snd_soc_component_read(component, CS4270_FORMAT);
367 	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
368 
369 	switch (cs4270->mode) {
370 	case SND_SOC_DAIFMT_I2S:
371 		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
372 		break;
373 	case SND_SOC_DAIFMT_LEFT_J:
374 		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
375 		break;
376 	default:
377 		dev_err(component->dev, "unknown dai format\n");
378 		return -EINVAL;
379 	}
380 
381 	ret = snd_soc_component_write(component, CS4270_FORMAT, reg);
382 	if (ret < 0) {
383 		dev_err(component->dev, "i2c write failed\n");
384 		return ret;
385 	}
386 
387 	return ret;
388 }
389 
390 /**
391  * cs4270_dai_mute - enable/disable the CS4270 external mute
392  * @dai: the SOC DAI
393  * @mute: 0 = disable mute, 1 = enable mute
394  * @direction: (ignored)
395  *
396  * This function toggles the mute bits in the MUTE register.  The CS4270's
397  * mute capability is intended for external muting circuitry, so if the
398  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
399  * then this function will do nothing.
400  */
401 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute, int direction)
402 {
403 	struct snd_soc_component *component = dai->component;
404 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
405 	int reg6;
406 
407 	reg6 = snd_soc_component_read(component, CS4270_MUTE);
408 
409 	if (mute)
410 		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
411 	else {
412 		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
413 		reg6 |= cs4270->manual_mute;
414 	}
415 
416 	return snd_soc_component_write(component, CS4270_MUTE, reg6);
417 }
418 
419 /**
420  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
421  * 			 alsa control.
422  * @kcontrol: mixer control
423  * @ucontrol: control element information
424  *
425  * This function basically passes the arguments on to the generic
426  * snd_soc_put_volsw() function and saves the mute information in
427  * our private data structure. This is because we want to prevent
428  * cs4270_dai_mute() neglecting the user's decision to manually
429  * mute the codec's output.
430  *
431  * Returns 0 for success.
432  */
433 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
434 				struct snd_ctl_elem_value *ucontrol)
435 {
436 	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);
437 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
438 	int left = !ucontrol->value.integer.value[0];
439 	int right = !ucontrol->value.integer.value[1];
440 
441 	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
442 			      (right ? CS4270_MUTE_DAC_B : 0);
443 
444 	return snd_soc_put_volsw(kcontrol, ucontrol);
445 }
446 
447 /* A list of non-DAPM controls that the CS4270 supports */
448 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
449 	SOC_DOUBLE_R("Master Playback Volume",
450 		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
451 	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
452 	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
453 	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
454 	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
455 	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
456 	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
457 	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
458 	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
459 		snd_soc_get_volsw, cs4270_soc_put_mute),
460 };
461 
462 static const struct snd_soc_dai_ops cs4270_dai_ops = {
463 	.hw_params	= cs4270_hw_params,
464 	.set_sysclk	= cs4270_set_dai_sysclk,
465 	.set_fmt	= cs4270_set_dai_fmt,
466 	.mute_stream	= cs4270_dai_mute,
467 	.no_capture_mute = 1,
468 };
469 
470 static struct snd_soc_dai_driver cs4270_dai = {
471 	.name = "cs4270-hifi",
472 	.playback = {
473 		.stream_name = "Playback",
474 		.channels_min = 2,
475 		.channels_max = 2,
476 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
477 		.rate_min = 4000,
478 		.rate_max = 216000,
479 		.formats = CS4270_FORMATS,
480 	},
481 	.capture = {
482 		.stream_name = "Capture",
483 		.channels_min = 2,
484 		.channels_max = 2,
485 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
486 		.rate_min = 4000,
487 		.rate_max = 216000,
488 		.formats = CS4270_FORMATS,
489 	},
490 	.ops = &cs4270_dai_ops,
491 };
492 
493 /**
494  * cs4270_probe - ASoC probe function
495  * @component: ASoC component
496  *
497  * This function is called when ASoC has all the pieces it needs to
498  * instantiate a sound driver.
499  */
500 static int cs4270_probe(struct snd_soc_component *component)
501 {
502 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
503 	int ret;
504 
505 	/* Disable auto-mute.  This feature appears to be buggy.  In some
506 	 * situations, auto-mute will not deactivate when it should, so we want
507 	 * this feature disabled by default.  An application (e.g. alsactl) can
508 	 * re-enabled it by using the controls.
509 	 */
510 	ret = snd_soc_component_update_bits(component, CS4270_MUTE, CS4270_MUTE_AUTO, 0);
511 	if (ret < 0) {
512 		dev_err(component->dev, "i2c write failed\n");
513 		return ret;
514 	}
515 
516 	/* Disable automatic volume control.  The hardware enables, and it
517 	 * causes volume change commands to be delayed, sometimes until after
518 	 * playback has started.  An application (e.g. alsactl) can
519 	 * re-enabled it by using the controls.
520 	 */
521 	ret = snd_soc_component_update_bits(component, CS4270_TRANS,
522 		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);
523 	if (ret < 0) {
524 		dev_err(component->dev, "i2c write failed\n");
525 		return ret;
526 	}
527 
528 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
529 				    cs4270->supplies);
530 
531 	return ret;
532 }
533 
534 /**
535  * cs4270_remove - ASoC remove function
536  * @component: ASoC component
537  *
538  * This function is the counterpart to cs4270_probe().
539  */
540 static void cs4270_remove(struct snd_soc_component *component)
541 {
542 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
543 
544 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
545 };
546 
547 #ifdef CONFIG_PM
548 
549 /* This suspend/resume implementation can handle both - a simple standby
550  * where the codec remains powered, and a full suspend, where the voltage
551  * domain the codec is connected to is teared down and/or any other hardware
552  * reset condition is asserted.
553  *
554  * The codec's own power saving features are enabled in the suspend callback,
555  * and all registers are written back to the hardware when resuming.
556  */
557 
558 static int cs4270_soc_suspend(struct snd_soc_component *component)
559 {
560 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
561 	int reg, ret;
562 
563 	reg = snd_soc_component_read(component, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
564 	if (reg < 0)
565 		return reg;
566 
567 	ret = snd_soc_component_write(component, CS4270_PWRCTL, reg);
568 	if (ret < 0)
569 		return ret;
570 
571 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
572 			       cs4270->supplies);
573 
574 	return 0;
575 }
576 
577 static int cs4270_soc_resume(struct snd_soc_component *component)
578 {
579 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
580 	int reg, ret;
581 
582 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
583 				    cs4270->supplies);
584 	if (ret != 0)
585 		return ret;
586 
587 	/* In case the device was put to hard reset during sleep, we need to
588 	 * wait 500ns here before any I2C communication. */
589 	ndelay(500);
590 
591 	/* first restore the entire register cache ... */
592 	regcache_sync(cs4270->regmap);
593 
594 	/* ... then disable the power-down bits */
595 	reg = snd_soc_component_read(component, CS4270_PWRCTL);
596 	reg &= ~CS4270_PWRCTL_PDN_ALL;
597 
598 	return snd_soc_component_write(component, CS4270_PWRCTL, reg);
599 }
600 #else
601 #define cs4270_soc_suspend	NULL
602 #define cs4270_soc_resume	NULL
603 #endif /* CONFIG_PM */
604 
605 /*
606  * ASoC codec driver structure
607  */
608 static const struct snd_soc_component_driver soc_component_device_cs4270 = {
609 	.probe			= cs4270_probe,
610 	.remove			= cs4270_remove,
611 	.suspend		= cs4270_soc_suspend,
612 	.resume			= cs4270_soc_resume,
613 	.controls		= cs4270_snd_controls,
614 	.num_controls		= ARRAY_SIZE(cs4270_snd_controls),
615 	.dapm_widgets		= cs4270_dapm_widgets,
616 	.num_dapm_widgets	= ARRAY_SIZE(cs4270_dapm_widgets),
617 	.dapm_routes		= cs4270_dapm_routes,
618 	.num_dapm_routes	= ARRAY_SIZE(cs4270_dapm_routes),
619 	.idle_bias_on		= 1,
620 	.use_pmdown_time	= 1,
621 	.endianness		= 1,
622 };
623 
624 /*
625  * cs4270_of_match - the device tree bindings
626  */
627 static const struct of_device_id cs4270_of_match[] = {
628 	{ .compatible = "cirrus,cs4270", },
629 	{ }
630 };
631 MODULE_DEVICE_TABLE(of, cs4270_of_match);
632 
633 static const struct regmap_config cs4270_regmap = {
634 	.reg_bits =		8,
635 	.val_bits =		8,
636 	.max_register =		CS4270_LASTREG,
637 	.reg_defaults =		cs4270_reg_defaults,
638 	.num_reg_defaults =	ARRAY_SIZE(cs4270_reg_defaults),
639 	.cache_type =		REGCACHE_MAPLE,
640 	.write_flag_mask =	CS4270_I2C_INCR,
641 
642 	.readable_reg =		cs4270_reg_is_readable,
643 	.volatile_reg =		cs4270_reg_is_volatile,
644 };
645 
646 /**
647  * cs4270_i2c_remove - deinitialize the I2C interface of the CS4270
648  * @i2c_client: the I2C client object
649  *
650  * This function puts the chip into low power mode when the i2c device
651  * is removed.
652  */
653 static void cs4270_i2c_remove(struct i2c_client *i2c_client)
654 {
655 	struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client);
656 
657 	gpiod_set_value_cansleep(cs4270->reset_gpio, 0);
658 }
659 
660 /**
661  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
662  * @i2c_client: the I2C client object
663  *
664  * This function is called whenever the I2C subsystem finds a device that
665  * matches the device ID given via a prior call to i2c_add_driver().
666  */
667 static int cs4270_i2c_probe(struct i2c_client *i2c_client)
668 {
669 	struct cs4270_private *cs4270;
670 	unsigned int val;
671 	int ret, i;
672 
673 	cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),
674 			      GFP_KERNEL);
675 	if (!cs4270)
676 		return -ENOMEM;
677 
678 	/* get the power supply regulators */
679 	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
680 		cs4270->supplies[i].supply = supply_names[i];
681 
682 	ret = devm_regulator_bulk_get(&i2c_client->dev,
683 				      ARRAY_SIZE(cs4270->supplies),
684 				      cs4270->supplies);
685 	if (ret < 0)
686 		return ret;
687 
688 	/* reset the device */
689 	cs4270->reset_gpio = devm_gpiod_get_optional(&i2c_client->dev, "reset",
690 						     GPIOD_OUT_LOW);
691 	if (IS_ERR(cs4270->reset_gpio)) {
692 		dev_dbg(&i2c_client->dev, "Error getting CS4270 reset GPIO\n");
693 		return PTR_ERR(cs4270->reset_gpio);
694 	}
695 
696 	if (cs4270->reset_gpio) {
697 		dev_dbg(&i2c_client->dev, "Found reset GPIO\n");
698 		gpiod_set_value_cansleep(cs4270->reset_gpio, 1);
699 	}
700 
701 	/* Sleep 500ns before i2c communications */
702 	ndelay(500);
703 
704 	cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);
705 	if (IS_ERR(cs4270->regmap))
706 		return PTR_ERR(cs4270->regmap);
707 
708 	/* Verify that we have a CS4270 */
709 	ret = regmap_read(cs4270->regmap, CS4270_CHIPID, &val);
710 	if (ret < 0) {
711 		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
712 		       i2c_client->addr);
713 		return ret;
714 	}
715 	/* The top four bits of the chip ID should be 1100. */
716 	if ((val & 0xF0) != 0xC0) {
717 		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
718 		       i2c_client->addr);
719 		return -ENODEV;
720 	}
721 
722 	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
723 		i2c_client->addr);
724 	dev_info(&i2c_client->dev, "hardware revision %X\n", val & 0xF);
725 
726 	i2c_set_clientdata(i2c_client, cs4270);
727 
728 	ret = devm_snd_soc_register_component(&i2c_client->dev,
729 			&soc_component_device_cs4270, &cs4270_dai, 1);
730 	return ret;
731 }
732 
733 /*
734  * cs4270_id - I2C device IDs supported by this driver
735  */
736 static const struct i2c_device_id cs4270_id[] = {
737 	{"cs4270"},
738 	{}
739 };
740 MODULE_DEVICE_TABLE(i2c, cs4270_id);
741 
742 /*
743  * cs4270_i2c_driver - I2C device identification
744  *
745  * This structure tells the I2C subsystem how to identify and support a
746  * given I2C device type.
747  */
748 static struct i2c_driver cs4270_i2c_driver = {
749 	.driver = {
750 		.name = "cs4270",
751 		.of_match_table = cs4270_of_match,
752 	},
753 	.id_table = cs4270_id,
754 	.probe = cs4270_i2c_probe,
755 	.remove = cs4270_i2c_remove,
756 };
757 
758 module_i2c_driver(cs4270_i2c_driver);
759 
760 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
761 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
762 MODULE_LICENSE("GPL");
763