xref: /openbmc/linux/sound/soc/codecs/cs4270.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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/platform_device.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 
34 /*
35  * The codec isn't really big-endian or little-endian, since the I2S
36  * interface requires data to be sent serially with the MSbit first.
37  * However, to support BE and LE I2S devices, we specify both here.  That
38  * way, ALSA will always match the bit patterns.
39  */
40 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
41 			SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
42 			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
43 			SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
44 			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
45 			SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
46 
47 /* CS4270 registers addresses */
48 #define CS4270_CHIPID	0x01	/* Chip ID */
49 #define CS4270_PWRCTL	0x02	/* Power Control */
50 #define CS4270_MODE	0x03	/* Mode Control */
51 #define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
52 #define CS4270_TRANS	0x05	/* Transition Control */
53 #define CS4270_MUTE	0x06	/* Mute Control */
54 #define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
55 #define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
56 
57 #define CS4270_FIRSTREG	0x01
58 #define CS4270_LASTREG	0x08
59 #define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
60 #define CS4270_I2C_INCR	0x80
61 
62 /* Bit masks for the CS4270 registers */
63 #define CS4270_CHIPID_ID	0xF0
64 #define CS4270_CHIPID_REV	0x0F
65 #define CS4270_PWRCTL_FREEZE	0x80
66 #define CS4270_PWRCTL_PDN_ADC	0x20
67 #define CS4270_PWRCTL_PDN_DAC	0x02
68 #define CS4270_PWRCTL_PDN	0x01
69 #define CS4270_PWRCTL_PDN_ALL	\
70 	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
71 #define CS4270_MODE_SPEED_MASK	0x30
72 #define CS4270_MODE_1X		0x00
73 #define CS4270_MODE_2X		0x10
74 #define CS4270_MODE_4X		0x20
75 #define CS4270_MODE_SLAVE	0x30
76 #define CS4270_MODE_DIV_MASK	0x0E
77 #define CS4270_MODE_DIV1	0x00
78 #define CS4270_MODE_DIV15	0x02
79 #define CS4270_MODE_DIV2	0x04
80 #define CS4270_MODE_DIV3	0x06
81 #define CS4270_MODE_DIV4	0x08
82 #define CS4270_MODE_POPGUARD	0x01
83 #define CS4270_FORMAT_FREEZE_A	0x80
84 #define CS4270_FORMAT_FREEZE_B	0x40
85 #define CS4270_FORMAT_LOOPBACK	0x20
86 #define CS4270_FORMAT_DAC_MASK	0x18
87 #define CS4270_FORMAT_DAC_LJ	0x00
88 #define CS4270_FORMAT_DAC_I2S	0x08
89 #define CS4270_FORMAT_DAC_RJ16	0x18
90 #define CS4270_FORMAT_DAC_RJ24	0x10
91 #define CS4270_FORMAT_ADC_MASK	0x01
92 #define CS4270_FORMAT_ADC_LJ	0x00
93 #define CS4270_FORMAT_ADC_I2S	0x01
94 #define CS4270_TRANS_ONE_VOL	0x80
95 #define CS4270_TRANS_SOFT	0x40
96 #define CS4270_TRANS_ZERO	0x20
97 #define CS4270_TRANS_INV_ADC_A	0x08
98 #define CS4270_TRANS_INV_ADC_B	0x10
99 #define CS4270_TRANS_INV_DAC_A	0x02
100 #define CS4270_TRANS_INV_DAC_B	0x04
101 #define CS4270_TRANS_DEEMPH	0x01
102 #define CS4270_MUTE_AUTO	0x20
103 #define CS4270_MUTE_ADC_A	0x08
104 #define CS4270_MUTE_ADC_B	0x10
105 #define CS4270_MUTE_POLARITY	0x04
106 #define CS4270_MUTE_DAC_A	0x01
107 #define CS4270_MUTE_DAC_B	0x02
108 
109 static const char *supply_names[] = {
110 	"va", "vd", "vlc"
111 };
112 
113 /* Private data for the CS4270 */
114 struct cs4270_private {
115 	enum snd_soc_control_type control_type;
116 	void *control_data;
117 	u8 reg_cache[CS4270_NUMREGS];
118 	unsigned int mclk; /* Input frequency of the MCLK pin */
119 	unsigned int mode; /* The mode (I2S or left-justified) */
120 	unsigned int slave_mode;
121 	unsigned int manual_mute;
122 
123 	/* power domain regulators */
124 	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
125 };
126 
127 /**
128  * struct cs4270_mode_ratios - clock ratio tables
129  * @ratio: the ratio of MCLK to the sample rate
130  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
131  *              this ratio
132  * @mclk: the Ratio Select bits to set in the Mode Control register for this
133  *        ratio
134  *
135  * The data for this chart is taken from Table 5 of the CS4270 reference
136  * manual.
137  *
138  * This table is used to determine how to program the Mode Control register.
139  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
140  * rates the CS4270 currently supports.
141  *
142  * @speed_mode is the corresponding bit pattern to be written to the
143  * MODE bits of the Mode Control Register
144  *
145  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
146  * the Mode Control Register.
147  *
148  * In situations where a single ratio is represented by multiple speed
149  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
150  * double-speed instead of quad-speed.  However, the CS4270 errata states
151  * that divide-By-1.5 can cause failures, so we avoid that mode where
152  * possible.
153  *
154  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
155  * work if Vd is 3.3V.  If this effects you, select the
156  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
157  * never select any sample rates that require divide-by-1.5.
158  */
159 struct cs4270_mode_ratios {
160 	unsigned int ratio;
161 	u8 speed_mode;
162 	u8 mclk;
163 };
164 
165 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
166 	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
167 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
168 	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
169 #endif
170 	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
171 	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
172 	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
173 	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
174 	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
175 	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
176 	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
177 };
178 
179 /* The number of MCLK/LRCK ratios supported by the CS4270 */
180 #define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
181 
182 /**
183  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
184  * @codec_dai: the codec DAI
185  * @clk_id: the clock ID (ignored)
186  * @freq: the MCLK input frequency
187  * @dir: the clock direction (ignored)
188  *
189  * This function is used to tell the codec driver what the input MCLK
190  * frequency is.
191  *
192  * The value of MCLK is used to determine which sample rates are supported
193  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
194  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
195  *
196  * This function calculates the nine ratios and determines which ones match
197  * a standard sample rate.  If there's a match, then it is added to the list
198  * of supported sample rates.
199  *
200  * This function must be called by the machine driver's 'startup' function,
201  * otherwise the list of supported sample rates will not be available in
202  * time for ALSA.
203  *
204  * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
205  * theoretically possible sample rates to be enabled. Call it again with a
206  * proper value set one the external clock is set (most probably you would do
207  * that from a machine's driver 'hw_param' hook.
208  */
209 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
210 				 int clk_id, unsigned int freq, int dir)
211 {
212 	struct snd_soc_codec *codec = codec_dai->codec;
213 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
214 
215 	cs4270->mclk = freq;
216 	return 0;
217 }
218 
219 /**
220  * cs4270_set_dai_fmt - configure the codec for the selected audio format
221  * @codec_dai: the codec DAI
222  * @format: a SND_SOC_DAIFMT_x value indicating the data format
223  *
224  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
225  * codec accordingly.
226  *
227  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
228  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
229  * data for playback only, but ASoC currently does not support different
230  * formats for playback vs. record.
231  */
232 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
233 			      unsigned int format)
234 {
235 	struct snd_soc_codec *codec = codec_dai->codec;
236 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
237 	int ret = 0;
238 
239 	/* set DAI format */
240 	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
241 	case SND_SOC_DAIFMT_I2S:
242 	case SND_SOC_DAIFMT_LEFT_J:
243 		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
244 		break;
245 	default:
246 		dev_err(codec->dev, "invalid dai format\n");
247 		ret = -EINVAL;
248 	}
249 
250 	/* set master/slave audio interface */
251 	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
252 	case SND_SOC_DAIFMT_CBS_CFS:
253 		cs4270->slave_mode = 1;
254 		break;
255 	case SND_SOC_DAIFMT_CBM_CFM:
256 		cs4270->slave_mode = 0;
257 		break;
258 	default:
259 		/* all other modes are unsupported by the hardware */
260 		ret = -EINVAL;
261 	}
262 
263 	return ret;
264 }
265 
266 /**
267  * cs4270_fill_cache - pre-fill the CS4270 register cache.
268  * @codec: the codec for this CS4270
269  *
270  * This function fills in the CS4270 register cache by reading the register
271  * values from the hardware.
272  *
273  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
274  * After the initial read to pre-fill the cache, the CS4270 never updates
275  * the register values, so we won't have a cache coherency problem.
276  *
277  * We use the auto-increment feature of the CS4270 to read all registers in
278  * one shot.
279  */
280 static int cs4270_fill_cache(struct snd_soc_codec *codec)
281 {
282 	u8 *cache = codec->reg_cache;
283 	struct i2c_client *i2c_client = codec->control_data;
284 	s32 length;
285 
286 	length = i2c_smbus_read_i2c_block_data(i2c_client,
287 		CS4270_FIRSTREG | CS4270_I2C_INCR, CS4270_NUMREGS, cache);
288 
289 	if (length != CS4270_NUMREGS) {
290 		dev_err(codec->dev, "i2c read failure, addr=0x%x\n",
291 		       i2c_client->addr);
292 		return -EIO;
293 	}
294 
295 	return 0;
296 }
297 
298 /**
299  * cs4270_read_reg_cache - read from the CS4270 register cache.
300  * @codec: the codec for this CS4270
301  * @reg: the register to read
302  *
303  * This function returns the value for a given register.  It reads only from
304  * the register cache, not the hardware itself.
305  *
306  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
307  * After the initial read to pre-fill the cache, the CS4270 never updates
308  * the register values, so we won't have a cache coherency problem.
309  */
310 static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec,
311 	unsigned int reg)
312 {
313 	u8 *cache = codec->reg_cache;
314 
315 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
316 		return -EIO;
317 
318 	return cache[reg - CS4270_FIRSTREG];
319 }
320 
321 /**
322  * cs4270_i2c_write - write to a CS4270 register via the I2C bus.
323  * @codec: the codec for this CS4270
324  * @reg: the register to write
325  * @value: the value to write to the register
326  *
327  * This function writes the given value to the given CS4270 register, and
328  * also updates the register cache.
329  *
330  * Note that we don't use the hw_write function pointer of snd_soc_codec.
331  * That's because it's too clunky: the hw_write_t prototype does not match
332  * i2c_smbus_write_byte_data(), and it's just another layer of overhead.
333  */
334 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
335 			    unsigned int value)
336 {
337 	u8 *cache = codec->reg_cache;
338 
339 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
340 		return -EIO;
341 
342 	/* Only perform an I2C operation if the new value is different */
343 	if (cache[reg - CS4270_FIRSTREG] != value) {
344 		struct i2c_client *client = codec->control_data;
345 		if (i2c_smbus_write_byte_data(client, reg, value)) {
346 			dev_err(codec->dev, "i2c write failed\n");
347 			return -EIO;
348 		}
349 
350 		/* We've written to the hardware, so update the cache */
351 		cache[reg - CS4270_FIRSTREG] = value;
352 	}
353 
354 	return 0;
355 }
356 
357 /**
358  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
359  * @substream: the audio stream
360  * @params: the hardware parameters to set
361  * @dai: the SOC DAI (ignored)
362  *
363  * This function programs the hardware with the values provided.
364  * Specifically, the sample rate and the data format.
365  *
366  * The .ops functions are used to provide board-specific data, like input
367  * frequencies, to this driver.  This function takes that information,
368  * combines it with the hardware parameters provided, and programs the
369  * hardware accordingly.
370  */
371 static int cs4270_hw_params(struct snd_pcm_substream *substream,
372 			    struct snd_pcm_hw_params *params,
373 			    struct snd_soc_dai *dai)
374 {
375 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
376 	struct snd_soc_codec *codec = rtd->codec;
377 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
378 	int ret;
379 	unsigned int i;
380 	unsigned int rate;
381 	unsigned int ratio;
382 	int reg;
383 
384 	/* Figure out which MCLK/LRCK ratio to use */
385 
386 	rate = params_rate(params);	/* Sampling rate, in Hz */
387 	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
388 
389 	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
390 		if (cs4270_mode_ratios[i].ratio == ratio)
391 			break;
392 	}
393 
394 	if (i == NUM_MCLK_RATIOS) {
395 		/* We did not find a matching ratio */
396 		dev_err(codec->dev, "could not find matching ratio\n");
397 		return -EINVAL;
398 	}
399 
400 	/* Set the sample rate */
401 
402 	reg = snd_soc_read(codec, CS4270_MODE);
403 	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
404 	reg |= cs4270_mode_ratios[i].mclk;
405 
406 	if (cs4270->slave_mode)
407 		reg |= CS4270_MODE_SLAVE;
408 	else
409 		reg |= cs4270_mode_ratios[i].speed_mode;
410 
411 	ret = snd_soc_write(codec, CS4270_MODE, reg);
412 	if (ret < 0) {
413 		dev_err(codec->dev, "i2c write failed\n");
414 		return ret;
415 	}
416 
417 	/* Set the DAI format */
418 
419 	reg = snd_soc_read(codec, CS4270_FORMAT);
420 	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
421 
422 	switch (cs4270->mode) {
423 	case SND_SOC_DAIFMT_I2S:
424 		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
425 		break;
426 	case SND_SOC_DAIFMT_LEFT_J:
427 		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
428 		break;
429 	default:
430 		dev_err(codec->dev, "unknown dai format\n");
431 		return -EINVAL;
432 	}
433 
434 	ret = snd_soc_write(codec, CS4270_FORMAT, reg);
435 	if (ret < 0) {
436 		dev_err(codec->dev, "i2c write failed\n");
437 		return ret;
438 	}
439 
440 	return ret;
441 }
442 
443 /**
444  * cs4270_dai_mute - enable/disable the CS4270 external mute
445  * @dai: the SOC DAI
446  * @mute: 0 = disable mute, 1 = enable mute
447  *
448  * This function toggles the mute bits in the MUTE register.  The CS4270's
449  * mute capability is intended for external muting circuitry, so if the
450  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
451  * then this function will do nothing.
452  */
453 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
454 {
455 	struct snd_soc_codec *codec = dai->codec;
456 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
457 	int reg6;
458 
459 	reg6 = snd_soc_read(codec, CS4270_MUTE);
460 
461 	if (mute)
462 		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
463 	else {
464 		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
465 		reg6 |= cs4270->manual_mute;
466 	}
467 
468 	return snd_soc_write(codec, CS4270_MUTE, reg6);
469 }
470 
471 /**
472  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
473  * 			 alsa control.
474  * @kcontrol: mixer control
475  * @ucontrol: control element information
476  *
477  * This function basically passes the arguments on to the generic
478  * snd_soc_put_volsw() function and saves the mute information in
479  * our private data structure. This is because we want to prevent
480  * cs4270_dai_mute() neglecting the user's decision to manually
481  * mute the codec's output.
482  *
483  * Returns 0 for success.
484  */
485 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
486 				struct snd_ctl_elem_value *ucontrol)
487 {
488 	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
489 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
490 	int left = !ucontrol->value.integer.value[0];
491 	int right = !ucontrol->value.integer.value[1];
492 
493 	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
494 			      (right ? CS4270_MUTE_DAC_B : 0);
495 
496 	return snd_soc_put_volsw(kcontrol, ucontrol);
497 }
498 
499 /* A list of non-DAPM controls that the CS4270 supports */
500 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
501 	SOC_DOUBLE_R("Master Playback Volume",
502 		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
503 	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
504 	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
505 	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
506 	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
507 	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
508 	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
509 	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
510 	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
511 		snd_soc_get_volsw, cs4270_soc_put_mute),
512 };
513 
514 static struct snd_soc_dai_ops cs4270_dai_ops = {
515 	.hw_params	= cs4270_hw_params,
516 	.set_sysclk	= cs4270_set_dai_sysclk,
517 	.set_fmt	= cs4270_set_dai_fmt,
518 	.digital_mute	= cs4270_dai_mute,
519 };
520 
521 static struct snd_soc_dai_driver cs4270_dai = {
522 	.name = "cs4270-hifi",
523 	.playback = {
524 		.stream_name = "Playback",
525 		.channels_min = 1,
526 		.channels_max = 2,
527 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
528 		.rate_min = 4000,
529 		.rate_max = 216000,
530 		.formats = CS4270_FORMATS,
531 	},
532 	.capture = {
533 		.stream_name = "Capture",
534 		.channels_min = 1,
535 		.channels_max = 2,
536 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
537 		.rate_min = 4000,
538 		.rate_max = 216000,
539 		.formats = CS4270_FORMATS,
540 	},
541 	.ops = &cs4270_dai_ops,
542 };
543 
544 /**
545  * cs4270_probe - ASoC probe function
546  * @pdev: platform device
547  *
548  * This function is called when ASoC has all the pieces it needs to
549  * instantiate a sound driver.
550  */
551 static int cs4270_probe(struct snd_soc_codec *codec)
552 {
553 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
554 	int i, ret, reg;
555 
556 	codec->control_data = cs4270->control_data;
557 
558 	/* The I2C interface is set up, so pre-fill our register cache */
559 
560 	ret = cs4270_fill_cache(codec);
561 	if (ret < 0) {
562 		dev_err(codec->dev, "failed to fill register cache\n");
563 		return ret;
564 	}
565 
566 	/* Disable auto-mute.  This feature appears to be buggy.  In some
567 	 * situations, auto-mute will not deactivate when it should, so we want
568 	 * this feature disabled by default.  An application (e.g. alsactl) can
569 	 * re-enabled it by using the controls.
570 	 */
571 
572 	reg = cs4270_read_reg_cache(codec, CS4270_MUTE);
573 	reg &= ~CS4270_MUTE_AUTO;
574 	ret = cs4270_i2c_write(codec, CS4270_MUTE, reg);
575 	if (ret < 0) {
576 		dev_err(codec->dev, "i2c write failed\n");
577 		return ret;
578 	}
579 
580 	/* Disable automatic volume control.  The hardware enables, and it
581 	 * causes volume change commands to be delayed, sometimes until after
582 	 * playback has started.  An application (e.g. alsactl) can
583 	 * re-enabled it by using the controls.
584 	 */
585 
586 	reg = cs4270_read_reg_cache(codec, CS4270_TRANS);
587 	reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO);
588 	ret = cs4270_i2c_write(codec, CS4270_TRANS, reg);
589 	if (ret < 0) {
590 		dev_err(codec->dev, "i2c write failed\n");
591 		return ret;
592 	}
593 
594 	/* Add the non-DAPM controls */
595 	ret = snd_soc_add_controls(codec, cs4270_snd_controls,
596 				ARRAY_SIZE(cs4270_snd_controls));
597 	if (ret < 0) {
598 		dev_err(codec->dev, "failed to add controls\n");
599 		return ret;
600 	}
601 
602 	/* get the power supply regulators */
603 	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
604 		cs4270->supplies[i].supply = supply_names[i];
605 
606 	ret = regulator_bulk_get(codec->dev, ARRAY_SIZE(cs4270->supplies),
607 				 cs4270->supplies);
608 	if (ret < 0)
609 		return ret;
610 
611 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
612 				    cs4270->supplies);
613 	if (ret < 0)
614 		goto error_free_regulators;
615 
616 	return 0;
617 
618 error_free_regulators:
619 	regulator_bulk_free(ARRAY_SIZE(cs4270->supplies),
620 			    cs4270->supplies);
621 
622 	return ret;
623 }
624 
625 /**
626  * cs4270_remove - ASoC remove function
627  * @pdev: platform device
628  *
629  * This function is the counterpart to cs4270_probe().
630  */
631 static int cs4270_remove(struct snd_soc_codec *codec)
632 {
633 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
634 
635 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
636 	regulator_bulk_free(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
637 
638 	return 0;
639 };
640 
641 #ifdef CONFIG_PM
642 
643 /* This suspend/resume implementation can handle both - a simple standby
644  * where the codec remains powered, and a full suspend, where the voltage
645  * domain the codec is connected to is teared down and/or any other hardware
646  * reset condition is asserted.
647  *
648  * The codec's own power saving features are enabled in the suspend callback,
649  * and all registers are written back to the hardware when resuming.
650  */
651 
652 static int cs4270_soc_suspend(struct snd_soc_codec *codec, pm_message_t mesg)
653 {
654 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
655 	int reg, ret;
656 
657 	reg = snd_soc_read(codec, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
658 	if (reg < 0)
659 		return reg;
660 
661 	ret = snd_soc_write(codec, CS4270_PWRCTL, reg);
662 	if (ret < 0)
663 		return ret;
664 
665 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
666 			       cs4270->supplies);
667 
668 	return 0;
669 }
670 
671 static int cs4270_soc_resume(struct snd_soc_codec *codec)
672 {
673 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
674 	struct i2c_client *i2c_client = codec->control_data;
675 	int reg;
676 
677 	regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
678 			      cs4270->supplies);
679 
680 	/* In case the device was put to hard reset during sleep, we need to
681 	 * wait 500ns here before any I2C communication. */
682 	ndelay(500);
683 
684 	/* first restore the entire register cache ... */
685 	for (reg = CS4270_FIRSTREG; reg <= CS4270_LASTREG; reg++) {
686 		u8 val = snd_soc_read(codec, reg);
687 
688 		if (i2c_smbus_write_byte_data(i2c_client, reg, val)) {
689 			dev_err(codec->dev, "i2c write failed\n");
690 			return -EIO;
691 		}
692 	}
693 
694 	/* ... then disable the power-down bits */
695 	reg = snd_soc_read(codec, CS4270_PWRCTL);
696 	reg &= ~CS4270_PWRCTL_PDN_ALL;
697 
698 	return snd_soc_write(codec, CS4270_PWRCTL, reg);
699 }
700 #else
701 #define cs4270_soc_suspend	NULL
702 #define cs4270_soc_resume	NULL
703 #endif /* CONFIG_PM */
704 
705 /*
706  * ASoC codec device structure
707  *
708  * Assign this variable to the codec_dev field of the machine driver's
709  * snd_soc_device structure.
710  */
711 static struct snd_soc_codec_driver soc_codec_device_cs4270 = {
712 	.probe =	cs4270_probe,
713 	.remove =	cs4270_remove,
714 	.suspend =	cs4270_soc_suspend,
715 	.resume =	cs4270_soc_resume,
716 	.read = cs4270_read_reg_cache,
717 	.write = cs4270_i2c_write,
718 	.reg_cache_size = CS4270_NUMREGS,
719 	.reg_word_size = sizeof(u8),
720 };
721 
722 /**
723  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
724  * @i2c_client: the I2C client object
725  * @id: the I2C device ID (ignored)
726  *
727  * This function is called whenever the I2C subsystem finds a device that
728  * matches the device ID given via a prior call to i2c_add_driver().
729  */
730 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
731 	const struct i2c_device_id *id)
732 {
733 	struct cs4270_private *cs4270;
734 	int ret;
735 
736 	/* Verify that we have a CS4270 */
737 
738 	ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID);
739 	if (ret < 0) {
740 		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
741 		       i2c_client->addr);
742 		return ret;
743 	}
744 	/* The top four bits of the chip ID should be 1100. */
745 	if ((ret & 0xF0) != 0xC0) {
746 		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
747 		       i2c_client->addr);
748 		return -ENODEV;
749 	}
750 
751 	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
752 		i2c_client->addr);
753 	dev_info(&i2c_client->dev, "hardware revision %X\n", ret & 0xF);
754 
755 	cs4270 = kzalloc(sizeof(struct cs4270_private), GFP_KERNEL);
756 	if (!cs4270) {
757 		dev_err(&i2c_client->dev, "could not allocate codec\n");
758 		return -ENOMEM;
759 	}
760 
761 	i2c_set_clientdata(i2c_client, cs4270);
762 	cs4270->control_data = i2c_client;
763 	cs4270->control_type = SND_SOC_I2C;
764 
765 	ret = snd_soc_register_codec(&i2c_client->dev,
766 			&soc_codec_device_cs4270, &cs4270_dai, 1);
767 	if (ret < 0)
768 		kfree(cs4270);
769 	return ret;
770 }
771 
772 /**
773  * cs4270_i2c_remove - remove an I2C device
774  * @i2c_client: the I2C client object
775  *
776  * This function is the counterpart to cs4270_i2c_probe().
777  */
778 static int cs4270_i2c_remove(struct i2c_client *i2c_client)
779 {
780 	snd_soc_unregister_codec(&i2c_client->dev);
781 	kfree(i2c_get_clientdata(i2c_client));
782 	return 0;
783 }
784 
785 /*
786  * cs4270_id - I2C device IDs supported by this driver
787  */
788 static struct i2c_device_id cs4270_id[] = {
789 	{"cs4270", 0},
790 	{}
791 };
792 MODULE_DEVICE_TABLE(i2c, cs4270_id);
793 
794 /*
795  * cs4270_i2c_driver - I2C device identification
796  *
797  * This structure tells the I2C subsystem how to identify and support a
798  * given I2C device type.
799  */
800 static struct i2c_driver cs4270_i2c_driver = {
801 	.driver = {
802 		.name = "cs4270-codec",
803 		.owner = THIS_MODULE,
804 	},
805 	.id_table = cs4270_id,
806 	.probe = cs4270_i2c_probe,
807 	.remove = cs4270_i2c_remove,
808 };
809 
810 static int __init cs4270_init(void)
811 {
812 	pr_info("Cirrus Logic CS4270 ALSA SoC Codec Driver\n");
813 
814 	return i2c_add_driver(&cs4270_i2c_driver);
815 }
816 module_init(cs4270_init);
817 
818 static void __exit cs4270_exit(void)
819 {
820 	i2c_del_driver(&cs4270_i2c_driver);
821 }
822 module_exit(cs4270_exit);
823 
824 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
825 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
826 MODULE_LICENSE("GPL");
827