xref: /openbmc/linux/sound/soc/codecs/cs4270.c (revision 95e9fd10)
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 
33 /*
34  * The codec isn't really big-endian or little-endian, since the I2S
35  * interface requires data to be sent serially with the MSbit first.
36  * However, to support BE and LE I2S devices, we specify both here.  That
37  * way, ALSA will always match the bit patterns.
38  */
39 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
40 			SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
41 			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
42 			SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
43 			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
44 			SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
45 
46 /* CS4270 registers addresses */
47 #define CS4270_CHIPID	0x01	/* Chip ID */
48 #define CS4270_PWRCTL	0x02	/* Power Control */
49 #define CS4270_MODE	0x03	/* Mode Control */
50 #define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
51 #define CS4270_TRANS	0x05	/* Transition Control */
52 #define CS4270_MUTE	0x06	/* Mute Control */
53 #define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
54 #define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
55 
56 #define CS4270_FIRSTREG	0x01
57 #define CS4270_LASTREG	0x08
58 #define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
59 #define CS4270_I2C_INCR	0x80
60 
61 /* Bit masks for the CS4270 registers */
62 #define CS4270_CHIPID_ID	0xF0
63 #define CS4270_CHIPID_REV	0x0F
64 #define CS4270_PWRCTL_FREEZE	0x80
65 #define CS4270_PWRCTL_PDN_ADC	0x20
66 #define CS4270_PWRCTL_PDN_DAC	0x02
67 #define CS4270_PWRCTL_PDN	0x01
68 #define CS4270_PWRCTL_PDN_ALL	\
69 	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
70 #define CS4270_MODE_SPEED_MASK	0x30
71 #define CS4270_MODE_1X		0x00
72 #define CS4270_MODE_2X		0x10
73 #define CS4270_MODE_4X		0x20
74 #define CS4270_MODE_SLAVE	0x30
75 #define CS4270_MODE_DIV_MASK	0x0E
76 #define CS4270_MODE_DIV1	0x00
77 #define CS4270_MODE_DIV15	0x02
78 #define CS4270_MODE_DIV2	0x04
79 #define CS4270_MODE_DIV3	0x06
80 #define CS4270_MODE_DIV4	0x08
81 #define CS4270_MODE_POPGUARD	0x01
82 #define CS4270_FORMAT_FREEZE_A	0x80
83 #define CS4270_FORMAT_FREEZE_B	0x40
84 #define CS4270_FORMAT_LOOPBACK	0x20
85 #define CS4270_FORMAT_DAC_MASK	0x18
86 #define CS4270_FORMAT_DAC_LJ	0x00
87 #define CS4270_FORMAT_DAC_I2S	0x08
88 #define CS4270_FORMAT_DAC_RJ16	0x18
89 #define CS4270_FORMAT_DAC_RJ24	0x10
90 #define CS4270_FORMAT_ADC_MASK	0x01
91 #define CS4270_FORMAT_ADC_LJ	0x00
92 #define CS4270_FORMAT_ADC_I2S	0x01
93 #define CS4270_TRANS_ONE_VOL	0x80
94 #define CS4270_TRANS_SOFT	0x40
95 #define CS4270_TRANS_ZERO	0x20
96 #define CS4270_TRANS_INV_ADC_A	0x08
97 #define CS4270_TRANS_INV_ADC_B	0x10
98 #define CS4270_TRANS_INV_DAC_A	0x02
99 #define CS4270_TRANS_INV_DAC_B	0x04
100 #define CS4270_TRANS_DEEMPH	0x01
101 #define CS4270_MUTE_AUTO	0x20
102 #define CS4270_MUTE_ADC_A	0x08
103 #define CS4270_MUTE_ADC_B	0x10
104 #define CS4270_MUTE_POLARITY	0x04
105 #define CS4270_MUTE_DAC_A	0x01
106 #define CS4270_MUTE_DAC_B	0x02
107 
108 /* Power-on default values for the registers
109  *
110  * This array contains the power-on default values of the registers, with the
111  * exception of the "CHIPID" register (01h).  The lower four bits of that
112  * register contain the hardware revision, so it is treated as volatile.
113  *
114  * Also note that on the CS4270, the first readable register is 1, but ASoC
115  * assumes the first register is 0.  Therfore, the array must have an entry for
116  * register 0, but we use cs4270_reg_is_readable() to tell ASoC that it can't
117  * be read.
118  */
119 static const u8 cs4270_default_reg_cache[CS4270_LASTREG + 1] = {
120 	0x00, 0x00, 0x00, 0x30, 0x00, 0x60, 0x20, 0x00, 0x00
121 };
122 
123 static const char *supply_names[] = {
124 	"va", "vd", "vlc"
125 };
126 
127 /* Private data for the CS4270 */
128 struct cs4270_private {
129 	enum snd_soc_control_type control_type;
130 	unsigned int mclk; /* Input frequency of the MCLK pin */
131 	unsigned int mode; /* The mode (I2S or left-justified) */
132 	unsigned int slave_mode;
133 	unsigned int manual_mute;
134 
135 	/* power domain regulators */
136 	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
137 };
138 
139 /**
140  * struct cs4270_mode_ratios - clock ratio tables
141  * @ratio: the ratio of MCLK to the sample rate
142  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
143  *              this ratio
144  * @mclk: the Ratio Select bits to set in the Mode Control register for this
145  *        ratio
146  *
147  * The data for this chart is taken from Table 5 of the CS4270 reference
148  * manual.
149  *
150  * This table is used to determine how to program the Mode Control register.
151  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
152  * rates the CS4270 currently supports.
153  *
154  * @speed_mode is the corresponding bit pattern to be written to the
155  * MODE bits of the Mode Control Register
156  *
157  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
158  * the Mode Control Register.
159  *
160  * In situations where a single ratio is represented by multiple speed
161  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
162  * double-speed instead of quad-speed.  However, the CS4270 errata states
163  * that divide-By-1.5 can cause failures, so we avoid that mode where
164  * possible.
165  *
166  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
167  * work if Vd is 3.3V.  If this effects you, select the
168  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
169  * never select any sample rates that require divide-by-1.5.
170  */
171 struct cs4270_mode_ratios {
172 	unsigned int ratio;
173 	u8 speed_mode;
174 	u8 mclk;
175 };
176 
177 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
178 	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
179 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
180 	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
181 #endif
182 	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
183 	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
184 	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
185 	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
186 	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
187 	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
188 	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
189 };
190 
191 /* The number of MCLK/LRCK ratios supported by the CS4270 */
192 #define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
193 
194 static int cs4270_reg_is_readable(struct snd_soc_codec *codec, unsigned int reg)
195 {
196 	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);
197 }
198 
199 static int cs4270_reg_is_volatile(struct snd_soc_codec *codec, unsigned int reg)
200 {
201 	/* Unreadable registers are considered volatile */
202 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
203 		return 1;
204 
205 	return reg == CS4270_CHIPID;
206 }
207 
208 /**
209  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
210  * @codec_dai: the codec DAI
211  * @clk_id: the clock ID (ignored)
212  * @freq: the MCLK input frequency
213  * @dir: the clock direction (ignored)
214  *
215  * This function is used to tell the codec driver what the input MCLK
216  * frequency is.
217  *
218  * The value of MCLK is used to determine which sample rates are supported
219  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
220  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
221  *
222  * This function calculates the nine ratios and determines which ones match
223  * a standard sample rate.  If there's a match, then it is added to the list
224  * of supported sample rates.
225  *
226  * This function must be called by the machine driver's 'startup' function,
227  * otherwise the list of supported sample rates will not be available in
228  * time for ALSA.
229  *
230  * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
231  * theoretically possible sample rates to be enabled. Call it again with a
232  * proper value set one the external clock is set (most probably you would do
233  * that from a machine's driver 'hw_param' hook.
234  */
235 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
236 				 int clk_id, unsigned int freq, int dir)
237 {
238 	struct snd_soc_codec *codec = codec_dai->codec;
239 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
240 
241 	cs4270->mclk = freq;
242 	return 0;
243 }
244 
245 /**
246  * cs4270_set_dai_fmt - configure the codec for the selected audio format
247  * @codec_dai: the codec DAI
248  * @format: a SND_SOC_DAIFMT_x value indicating the data format
249  *
250  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
251  * codec accordingly.
252  *
253  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
254  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
255  * data for playback only, but ASoC currently does not support different
256  * formats for playback vs. record.
257  */
258 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
259 			      unsigned int format)
260 {
261 	struct snd_soc_codec *codec = codec_dai->codec;
262 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
263 
264 	/* set DAI format */
265 	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
266 	case SND_SOC_DAIFMT_I2S:
267 	case SND_SOC_DAIFMT_LEFT_J:
268 		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
269 		break;
270 	default:
271 		dev_err(codec->dev, "invalid dai format\n");
272 		return -EINVAL;
273 	}
274 
275 	/* set master/slave audio interface */
276 	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
277 	case SND_SOC_DAIFMT_CBS_CFS:
278 		cs4270->slave_mode = 1;
279 		break;
280 	case SND_SOC_DAIFMT_CBM_CFM:
281 		cs4270->slave_mode = 0;
282 		break;
283 	default:
284 		/* all other modes are unsupported by the hardware */
285 		dev_err(codec->dev, "Unknown master/slave configuration\n");
286 		return -EINVAL;
287 	}
288 
289 	return 0;
290 }
291 
292 /**
293  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
294  * @substream: the audio stream
295  * @params: the hardware parameters to set
296  * @dai: the SOC DAI (ignored)
297  *
298  * This function programs the hardware with the values provided.
299  * Specifically, the sample rate and the data format.
300  *
301  * The .ops functions are used to provide board-specific data, like input
302  * frequencies, to this driver.  This function takes that information,
303  * combines it with the hardware parameters provided, and programs the
304  * hardware accordingly.
305  */
306 static int cs4270_hw_params(struct snd_pcm_substream *substream,
307 			    struct snd_pcm_hw_params *params,
308 			    struct snd_soc_dai *dai)
309 {
310 	struct snd_soc_codec *codec = dai->codec;
311 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
312 	int ret;
313 	unsigned int i;
314 	unsigned int rate;
315 	unsigned int ratio;
316 	int reg;
317 
318 	/* Figure out which MCLK/LRCK ratio to use */
319 
320 	rate = params_rate(params);	/* Sampling rate, in Hz */
321 	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
322 
323 	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
324 		if (cs4270_mode_ratios[i].ratio == ratio)
325 			break;
326 	}
327 
328 	if (i == NUM_MCLK_RATIOS) {
329 		/* We did not find a matching ratio */
330 		dev_err(codec->dev, "could not find matching ratio\n");
331 		return -EINVAL;
332 	}
333 
334 	/* Set the sample rate */
335 
336 	reg = snd_soc_read(codec, CS4270_MODE);
337 	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
338 	reg |= cs4270_mode_ratios[i].mclk;
339 
340 	if (cs4270->slave_mode)
341 		reg |= CS4270_MODE_SLAVE;
342 	else
343 		reg |= cs4270_mode_ratios[i].speed_mode;
344 
345 	ret = snd_soc_write(codec, CS4270_MODE, reg);
346 	if (ret < 0) {
347 		dev_err(codec->dev, "i2c write failed\n");
348 		return ret;
349 	}
350 
351 	/* Set the DAI format */
352 
353 	reg = snd_soc_read(codec, CS4270_FORMAT);
354 	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
355 
356 	switch (cs4270->mode) {
357 	case SND_SOC_DAIFMT_I2S:
358 		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
359 		break;
360 	case SND_SOC_DAIFMT_LEFT_J:
361 		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
362 		break;
363 	default:
364 		dev_err(codec->dev, "unknown dai format\n");
365 		return -EINVAL;
366 	}
367 
368 	ret = snd_soc_write(codec, CS4270_FORMAT, reg);
369 	if (ret < 0) {
370 		dev_err(codec->dev, "i2c write failed\n");
371 		return ret;
372 	}
373 
374 	return ret;
375 }
376 
377 /**
378  * cs4270_dai_mute - enable/disable the CS4270 external mute
379  * @dai: the SOC DAI
380  * @mute: 0 = disable mute, 1 = enable mute
381  *
382  * This function toggles the mute bits in the MUTE register.  The CS4270's
383  * mute capability is intended for external muting circuitry, so if the
384  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
385  * then this function will do nothing.
386  */
387 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
388 {
389 	struct snd_soc_codec *codec = dai->codec;
390 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
391 	int reg6;
392 
393 	reg6 = snd_soc_read(codec, CS4270_MUTE);
394 
395 	if (mute)
396 		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
397 	else {
398 		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
399 		reg6 |= cs4270->manual_mute;
400 	}
401 
402 	return snd_soc_write(codec, CS4270_MUTE, reg6);
403 }
404 
405 /**
406  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
407  * 			 alsa control.
408  * @kcontrol: mixer control
409  * @ucontrol: control element information
410  *
411  * This function basically passes the arguments on to the generic
412  * snd_soc_put_volsw() function and saves the mute information in
413  * our private data structure. This is because we want to prevent
414  * cs4270_dai_mute() neglecting the user's decision to manually
415  * mute the codec's output.
416  *
417  * Returns 0 for success.
418  */
419 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
420 				struct snd_ctl_elem_value *ucontrol)
421 {
422 	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
423 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
424 	int left = !ucontrol->value.integer.value[0];
425 	int right = !ucontrol->value.integer.value[1];
426 
427 	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
428 			      (right ? CS4270_MUTE_DAC_B : 0);
429 
430 	return snd_soc_put_volsw(kcontrol, ucontrol);
431 }
432 
433 /* A list of non-DAPM controls that the CS4270 supports */
434 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
435 	SOC_DOUBLE_R("Master Playback Volume",
436 		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
437 	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
438 	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
439 	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
440 	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
441 	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
442 	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
443 	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
444 	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
445 		snd_soc_get_volsw, cs4270_soc_put_mute),
446 };
447 
448 static const struct snd_soc_dai_ops cs4270_dai_ops = {
449 	.hw_params	= cs4270_hw_params,
450 	.set_sysclk	= cs4270_set_dai_sysclk,
451 	.set_fmt	= cs4270_set_dai_fmt,
452 	.digital_mute	= cs4270_dai_mute,
453 };
454 
455 static struct snd_soc_dai_driver cs4270_dai = {
456 	.name = "cs4270-hifi",
457 	.playback = {
458 		.stream_name = "Playback",
459 		.channels_min = 1,
460 		.channels_max = 2,
461 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
462 		.rate_min = 4000,
463 		.rate_max = 216000,
464 		.formats = CS4270_FORMATS,
465 	},
466 	.capture = {
467 		.stream_name = "Capture",
468 		.channels_min = 1,
469 		.channels_max = 2,
470 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
471 		.rate_min = 4000,
472 		.rate_max = 216000,
473 		.formats = CS4270_FORMATS,
474 	},
475 	.ops = &cs4270_dai_ops,
476 };
477 
478 /**
479  * cs4270_probe - ASoC probe function
480  * @pdev: platform device
481  *
482  * This function is called when ASoC has all the pieces it needs to
483  * instantiate a sound driver.
484  */
485 static int cs4270_probe(struct snd_soc_codec *codec)
486 {
487 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
488 	int i, ret;
489 
490 	/* Tell ASoC what kind of I/O to use to read the registers.  ASoC will
491 	 * then do the I2C transactions itself.
492 	 */
493 	ret = snd_soc_codec_set_cache_io(codec, 8, 8, cs4270->control_type);
494 	if (ret < 0) {
495 		dev_err(codec->dev, "failed to set cache I/O (ret=%i)\n", ret);
496 		return ret;
497 	}
498 
499 	/* Disable auto-mute.  This feature appears to be buggy.  In some
500 	 * situations, auto-mute will not deactivate when it should, so we want
501 	 * this feature disabled by default.  An application (e.g. alsactl) can
502 	 * re-enabled it by using the controls.
503 	 */
504 	ret = snd_soc_update_bits(codec, CS4270_MUTE, CS4270_MUTE_AUTO, 0);
505 	if (ret < 0) {
506 		dev_err(codec->dev, "i2c write failed\n");
507 		return ret;
508 	}
509 
510 	/* Disable automatic volume control.  The hardware enables, and it
511 	 * causes volume change commands to be delayed, sometimes until after
512 	 * playback has started.  An application (e.g. alsactl) can
513 	 * re-enabled it by using the controls.
514 	 */
515 	ret = snd_soc_update_bits(codec, CS4270_TRANS,
516 		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);
517 	if (ret < 0) {
518 		dev_err(codec->dev, "i2c write failed\n");
519 		return ret;
520 	}
521 
522 	/* Add the non-DAPM controls */
523 	ret = snd_soc_add_codec_controls(codec, cs4270_snd_controls,
524 				ARRAY_SIZE(cs4270_snd_controls));
525 	if (ret < 0) {
526 		dev_err(codec->dev, "failed to add controls\n");
527 		return ret;
528 	}
529 
530 	/* get the power supply regulators */
531 	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
532 		cs4270->supplies[i].supply = supply_names[i];
533 
534 	ret = regulator_bulk_get(codec->dev, ARRAY_SIZE(cs4270->supplies),
535 				 cs4270->supplies);
536 	if (ret < 0)
537 		return ret;
538 
539 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
540 				    cs4270->supplies);
541 	if (ret < 0)
542 		goto error_free_regulators;
543 
544 	return 0;
545 
546 error_free_regulators:
547 	regulator_bulk_free(ARRAY_SIZE(cs4270->supplies),
548 			    cs4270->supplies);
549 
550 	return ret;
551 }
552 
553 /**
554  * cs4270_remove - ASoC remove function
555  * @pdev: platform device
556  *
557  * This function is the counterpart to cs4270_probe().
558  */
559 static int cs4270_remove(struct snd_soc_codec *codec)
560 {
561 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
562 
563 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
564 	regulator_bulk_free(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
565 
566 	return 0;
567 };
568 
569 #ifdef CONFIG_PM
570 
571 /* This suspend/resume implementation can handle both - a simple standby
572  * where the codec remains powered, and a full suspend, where the voltage
573  * domain the codec is connected to is teared down and/or any other hardware
574  * reset condition is asserted.
575  *
576  * The codec's own power saving features are enabled in the suspend callback,
577  * and all registers are written back to the hardware when resuming.
578  */
579 
580 static int cs4270_soc_suspend(struct snd_soc_codec *codec)
581 {
582 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
583 	int reg, ret;
584 
585 	reg = snd_soc_read(codec, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
586 	if (reg < 0)
587 		return reg;
588 
589 	ret = snd_soc_write(codec, CS4270_PWRCTL, reg);
590 	if (ret < 0)
591 		return ret;
592 
593 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
594 			       cs4270->supplies);
595 
596 	return 0;
597 }
598 
599 static int cs4270_soc_resume(struct snd_soc_codec *codec)
600 {
601 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
602 	int reg, ret;
603 
604 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
605 				    cs4270->supplies);
606 	if (ret != 0)
607 		return ret;
608 
609 	/* In case the device was put to hard reset during sleep, we need to
610 	 * wait 500ns here before any I2C communication. */
611 	ndelay(500);
612 
613 	/* first restore the entire register cache ... */
614 	snd_soc_cache_sync(codec);
615 
616 	/* ... then disable the power-down bits */
617 	reg = snd_soc_read(codec, CS4270_PWRCTL);
618 	reg &= ~CS4270_PWRCTL_PDN_ALL;
619 
620 	return snd_soc_write(codec, CS4270_PWRCTL, reg);
621 }
622 #else
623 #define cs4270_soc_suspend	NULL
624 #define cs4270_soc_resume	NULL
625 #endif /* CONFIG_PM */
626 
627 /*
628  * ASoC codec driver structure
629  */
630 static const struct snd_soc_codec_driver soc_codec_device_cs4270 = {
631 	.probe =		cs4270_probe,
632 	.remove =		cs4270_remove,
633 	.suspend =		cs4270_soc_suspend,
634 	.resume =		cs4270_soc_resume,
635 	.volatile_register =	cs4270_reg_is_volatile,
636 	.readable_register =	cs4270_reg_is_readable,
637 	.reg_cache_size =	CS4270_LASTREG + 1,
638 	.reg_word_size =	sizeof(u8),
639 	.reg_cache_default =	cs4270_default_reg_cache,
640 };
641 
642 /**
643  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
644  * @i2c_client: the I2C client object
645  * @id: the I2C device ID (ignored)
646  *
647  * This function is called whenever the I2C subsystem finds a device that
648  * matches the device ID given via a prior call to i2c_add_driver().
649  */
650 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
651 	const struct i2c_device_id *id)
652 {
653 	struct cs4270_private *cs4270;
654 	int ret;
655 
656 	/* Verify that we have a CS4270 */
657 
658 	ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID);
659 	if (ret < 0) {
660 		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
661 		       i2c_client->addr);
662 		return ret;
663 	}
664 	/* The top four bits of the chip ID should be 1100. */
665 	if ((ret & 0xF0) != 0xC0) {
666 		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
667 		       i2c_client->addr);
668 		return -ENODEV;
669 	}
670 
671 	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
672 		i2c_client->addr);
673 	dev_info(&i2c_client->dev, "hardware revision %X\n", ret & 0xF);
674 
675 	cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),
676 			      GFP_KERNEL);
677 	if (!cs4270) {
678 		dev_err(&i2c_client->dev, "could not allocate codec\n");
679 		return -ENOMEM;
680 	}
681 
682 	i2c_set_clientdata(i2c_client, cs4270);
683 	cs4270->control_type = SND_SOC_I2C;
684 
685 	ret = snd_soc_register_codec(&i2c_client->dev,
686 			&soc_codec_device_cs4270, &cs4270_dai, 1);
687 	return ret;
688 }
689 
690 /**
691  * cs4270_i2c_remove - remove an I2C device
692  * @i2c_client: the I2C client object
693  *
694  * This function is the counterpart to cs4270_i2c_probe().
695  */
696 static int cs4270_i2c_remove(struct i2c_client *i2c_client)
697 {
698 	snd_soc_unregister_codec(&i2c_client->dev);
699 	return 0;
700 }
701 
702 /*
703  * cs4270_id - I2C device IDs supported by this driver
704  */
705 static const struct i2c_device_id cs4270_id[] = {
706 	{"cs4270", 0},
707 	{}
708 };
709 MODULE_DEVICE_TABLE(i2c, cs4270_id);
710 
711 /*
712  * cs4270_i2c_driver - I2C device identification
713  *
714  * This structure tells the I2C subsystem how to identify and support a
715  * given I2C device type.
716  */
717 static struct i2c_driver cs4270_i2c_driver = {
718 	.driver = {
719 		.name = "cs4270",
720 		.owner = THIS_MODULE,
721 	},
722 	.id_table = cs4270_id,
723 	.probe = cs4270_i2c_probe,
724 	.remove = cs4270_i2c_remove,
725 };
726 
727 static int __init cs4270_init(void)
728 {
729 	return i2c_add_driver(&cs4270_i2c_driver);
730 }
731 module_init(cs4270_init);
732 
733 static void __exit cs4270_exit(void)
734 {
735 	i2c_del_driver(&cs4270_i2c_driver);
736 }
737 module_exit(cs4270_exit);
738 
739 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
740 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
741 MODULE_LICENSE("GPL");
742