xref: /linux/sound/soc/codecs/cs4270.c (revision d39d0ed196aa1685bb24771e92f78633c66ac9cb)
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 #include "cs4270.h"
35 
36 /*
37  * The codec isn't really big-endian or little-endian, since the I2S
38  * interface requires data to be sent serially with the MSbit first.
39  * However, to support BE and LE I2S devices, we specify both here.  That
40  * way, ALSA will always match the bit patterns.
41  */
42 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
43 			SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
44 			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
45 			SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
46 			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
47 			SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
48 
49 /* CS4270 registers addresses */
50 #define CS4270_CHIPID	0x01	/* Chip ID */
51 #define CS4270_PWRCTL	0x02	/* Power Control */
52 #define CS4270_MODE	0x03	/* Mode Control */
53 #define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
54 #define CS4270_TRANS	0x05	/* Transition Control */
55 #define CS4270_MUTE	0x06	/* Mute Control */
56 #define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
57 #define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
58 
59 #define CS4270_FIRSTREG	0x01
60 #define CS4270_LASTREG	0x08
61 #define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
62 #define CS4270_I2C_INCR	0x80
63 
64 /* Bit masks for the CS4270 registers */
65 #define CS4270_CHIPID_ID	0xF0
66 #define CS4270_CHIPID_REV	0x0F
67 #define CS4270_PWRCTL_FREEZE	0x80
68 #define CS4270_PWRCTL_PDN_ADC	0x20
69 #define CS4270_PWRCTL_PDN_DAC	0x02
70 #define CS4270_PWRCTL_PDN	0x01
71 #define CS4270_PWRCTL_PDN_ALL	\
72 	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
73 #define CS4270_MODE_SPEED_MASK	0x30
74 #define CS4270_MODE_1X		0x00
75 #define CS4270_MODE_2X		0x10
76 #define CS4270_MODE_4X		0x20
77 #define CS4270_MODE_SLAVE	0x30
78 #define CS4270_MODE_DIV_MASK	0x0E
79 #define CS4270_MODE_DIV1	0x00
80 #define CS4270_MODE_DIV15	0x02
81 #define CS4270_MODE_DIV2	0x04
82 #define CS4270_MODE_DIV3	0x06
83 #define CS4270_MODE_DIV4	0x08
84 #define CS4270_MODE_POPGUARD	0x01
85 #define CS4270_FORMAT_FREEZE_A	0x80
86 #define CS4270_FORMAT_FREEZE_B	0x40
87 #define CS4270_FORMAT_LOOPBACK	0x20
88 #define CS4270_FORMAT_DAC_MASK	0x18
89 #define CS4270_FORMAT_DAC_LJ	0x00
90 #define CS4270_FORMAT_DAC_I2S	0x08
91 #define CS4270_FORMAT_DAC_RJ16	0x18
92 #define CS4270_FORMAT_DAC_RJ24	0x10
93 #define CS4270_FORMAT_ADC_MASK	0x01
94 #define CS4270_FORMAT_ADC_LJ	0x00
95 #define CS4270_FORMAT_ADC_I2S	0x01
96 #define CS4270_TRANS_ONE_VOL	0x80
97 #define CS4270_TRANS_SOFT	0x40
98 #define CS4270_TRANS_ZERO	0x20
99 #define CS4270_TRANS_INV_ADC_A	0x08
100 #define CS4270_TRANS_INV_ADC_B	0x10
101 #define CS4270_TRANS_INV_DAC_A	0x02
102 #define CS4270_TRANS_INV_DAC_B	0x04
103 #define CS4270_TRANS_DEEMPH	0x01
104 #define CS4270_MUTE_AUTO	0x20
105 #define CS4270_MUTE_ADC_A	0x08
106 #define CS4270_MUTE_ADC_B	0x10
107 #define CS4270_MUTE_POLARITY	0x04
108 #define CS4270_MUTE_DAC_A	0x01
109 #define CS4270_MUTE_DAC_B	0x02
110 
111 static const char *supply_names[] = {
112 	"va", "vd", "vlc"
113 };
114 
115 /* Private data for the CS4270 */
116 struct cs4270_private {
117 	struct snd_soc_codec codec;
118 	u8 reg_cache[CS4270_NUMREGS];
119 	unsigned int mclk; /* Input frequency of the MCLK pin */
120 	unsigned int mode; /* The mode (I2S or left-justified) */
121 	unsigned int slave_mode;
122 	unsigned int manual_mute;
123 
124 	/* power domain regulators */
125 	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
126 };
127 
128 /**
129  * struct cs4270_mode_ratios - clock ratio tables
130  * @ratio: the ratio of MCLK to the sample rate
131  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
132  *              this ratio
133  * @mclk: the Ratio Select bits to set in the Mode Control register for this
134  *        ratio
135  *
136  * The data for this chart is taken from Table 5 of the CS4270 reference
137  * manual.
138  *
139  * This table is used to determine how to program the Mode Control register.
140  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
141  * rates the CS4270 currently supports.
142  *
143  * @speed_mode is the corresponding bit pattern to be written to the
144  * MODE bits of the Mode Control Register
145  *
146  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
147  * the Mode Control Register.
148  *
149  * In situations where a single ratio is represented by multiple speed
150  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
151  * double-speed instead of quad-speed.  However, the CS4270 errata states
152  * that divide-By-1.5 can cause failures, so we avoid that mode where
153  * possible.
154  *
155  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
156  * work if Vd is 3.3V.  If this effects you, select the
157  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
158  * never select any sample rates that require divide-by-1.5.
159  */
160 struct cs4270_mode_ratios {
161 	unsigned int ratio;
162 	u8 speed_mode;
163 	u8 mclk;
164 };
165 
166 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
167 	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
168 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
169 	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
170 #endif
171 	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
172 	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
173 	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
174 	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
175 	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
176 	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
177 	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
178 };
179 
180 /* The number of MCLK/LRCK ratios supported by the CS4270 */
181 #define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
182 
183 /**
184  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
185  * @codec_dai: the codec DAI
186  * @clk_id: the clock ID (ignored)
187  * @freq: the MCLK input frequency
188  * @dir: the clock direction (ignored)
189  *
190  * This function is used to tell the codec driver what the input MCLK
191  * frequency is.
192  *
193  * The value of MCLK is used to determine which sample rates are supported
194  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
195  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
196  *
197  * This function calculates the nine ratios and determines which ones match
198  * a standard sample rate.  If there's a match, then it is added to the list
199  * of supported sample rates.
200  *
201  * This function must be called by the machine driver's 'startup' function,
202  * otherwise the list of supported sample rates will not be available in
203  * time for ALSA.
204  *
205  * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
206  * theoretically possible sample rates to be enabled. Call it again with a
207  * proper value set one the external clock is set (most probably you would do
208  * that from a machine's driver 'hw_param' hook.
209  */
210 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
211 				 int clk_id, unsigned int freq, int dir)
212 {
213 	struct snd_soc_codec *codec = codec_dai->codec;
214 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
215 	unsigned int rates = 0;
216 	unsigned int rate_min = -1;
217 	unsigned int rate_max = 0;
218 	unsigned int i;
219 
220 	cs4270->mclk = freq;
221 
222 	if (cs4270->mclk) {
223 		for (i = 0; i < NUM_MCLK_RATIOS; i++) {
224 			unsigned int rate = freq / cs4270_mode_ratios[i].ratio;
225 			rates |= snd_pcm_rate_to_rate_bit(rate);
226 			if (rate < rate_min)
227 				rate_min = rate;
228 			if (rate > rate_max)
229 				rate_max = rate;
230 		}
231 		/* FIXME: soc should support a rate list */
232 		rates &= ~SNDRV_PCM_RATE_KNOT;
233 
234 		if (!rates) {
235 			dev_err(codec->dev, "could not find a valid sample rate\n");
236 			return -EINVAL;
237 		}
238 	} else {
239 		/* enable all possible rates */
240 		rates = SNDRV_PCM_RATE_8000_192000;
241 		rate_min = 8000;
242 		rate_max = 192000;
243 	}
244 
245 	codec_dai->playback.rates = rates;
246 	codec_dai->playback.rate_min = rate_min;
247 	codec_dai->playback.rate_max = rate_max;
248 
249 	codec_dai->capture.rates = rates;
250 	codec_dai->capture.rate_min = rate_min;
251 	codec_dai->capture.rate_max = rate_max;
252 
253 	return 0;
254 }
255 
256 /**
257  * cs4270_set_dai_fmt - configure the codec for the selected audio format
258  * @codec_dai: the codec DAI
259  * @format: a SND_SOC_DAIFMT_x value indicating the data format
260  *
261  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
262  * codec accordingly.
263  *
264  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
265  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
266  * data for playback only, but ASoC currently does not support different
267  * formats for playback vs. record.
268  */
269 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
270 			      unsigned int format)
271 {
272 	struct snd_soc_codec *codec = codec_dai->codec;
273 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
274 	int ret = 0;
275 
276 	/* set DAI format */
277 	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
278 	case SND_SOC_DAIFMT_I2S:
279 	case SND_SOC_DAIFMT_LEFT_J:
280 		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
281 		break;
282 	default:
283 		dev_err(codec->dev, "invalid dai format\n");
284 		ret = -EINVAL;
285 	}
286 
287 	/* set master/slave audio interface */
288 	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
289 	case SND_SOC_DAIFMT_CBS_CFS:
290 		cs4270->slave_mode = 1;
291 		break;
292 	case SND_SOC_DAIFMT_CBM_CFM:
293 		cs4270->slave_mode = 0;
294 		break;
295 	default:
296 		/* all other modes are unsupported by the hardware */
297 		ret = -EINVAL;
298 	}
299 
300 	return ret;
301 }
302 
303 /**
304  * cs4270_fill_cache - pre-fill the CS4270 register cache.
305  * @codec: the codec for this CS4270
306  *
307  * This function fills in the CS4270 register cache by reading the register
308  * values from the hardware.
309  *
310  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
311  * After the initial read to pre-fill the cache, the CS4270 never updates
312  * the register values, so we won't have a cache coherency problem.
313  *
314  * We use the auto-increment feature of the CS4270 to read all registers in
315  * one shot.
316  */
317 static int cs4270_fill_cache(struct snd_soc_codec *codec)
318 {
319 	u8 *cache = codec->reg_cache;
320 	struct i2c_client *i2c_client = codec->control_data;
321 	s32 length;
322 
323 	length = i2c_smbus_read_i2c_block_data(i2c_client,
324 		CS4270_FIRSTREG | CS4270_I2C_INCR, CS4270_NUMREGS, cache);
325 
326 	if (length != CS4270_NUMREGS) {
327 		dev_err(codec->dev, "i2c read failure, addr=0x%x\n",
328 		       i2c_client->addr);
329 		return -EIO;
330 	}
331 
332 	return 0;
333 }
334 
335 /**
336  * cs4270_read_reg_cache - read from the CS4270 register cache.
337  * @codec: the codec for this CS4270
338  * @reg: the register to read
339  *
340  * This function returns the value for a given register.  It reads only from
341  * the register cache, not the hardware itself.
342  *
343  * This CS4270 registers are cached to avoid excessive I2C I/O operations.
344  * After the initial read to pre-fill the cache, the CS4270 never updates
345  * the register values, so we won't have a cache coherency problem.
346  */
347 static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec,
348 	unsigned int reg)
349 {
350 	u8 *cache = codec->reg_cache;
351 
352 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
353 		return -EIO;
354 
355 	return cache[reg - CS4270_FIRSTREG];
356 }
357 
358 /**
359  * cs4270_i2c_write - write to a CS4270 register via the I2C bus.
360  * @codec: the codec for this CS4270
361  * @reg: the register to write
362  * @value: the value to write to the register
363  *
364  * This function writes the given value to the given CS4270 register, and
365  * also updates the register cache.
366  *
367  * Note that we don't use the hw_write function pointer of snd_soc_codec.
368  * That's because it's too clunky: the hw_write_t prototype does not match
369  * i2c_smbus_write_byte_data(), and it's just another layer of overhead.
370  */
371 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
372 			    unsigned int value)
373 {
374 	u8 *cache = codec->reg_cache;
375 
376 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
377 		return -EIO;
378 
379 	/* Only perform an I2C operation if the new value is different */
380 	if (cache[reg - CS4270_FIRSTREG] != value) {
381 		struct i2c_client *client = codec->control_data;
382 		if (i2c_smbus_write_byte_data(client, reg, value)) {
383 			dev_err(codec->dev, "i2c write failed\n");
384 			return -EIO;
385 		}
386 
387 		/* We've written to the hardware, so update the cache */
388 		cache[reg - CS4270_FIRSTREG] = value;
389 	}
390 
391 	return 0;
392 }
393 
394 /**
395  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
396  * @substream: the audio stream
397  * @params: the hardware parameters to set
398  * @dai: the SOC DAI (ignored)
399  *
400  * This function programs the hardware with the values provided.
401  * Specifically, the sample rate and the data format.
402  *
403  * The .ops functions are used to provide board-specific data, like input
404  * frequencies, to this driver.  This function takes that information,
405  * combines it with the hardware parameters provided, and programs the
406  * hardware accordingly.
407  */
408 static int cs4270_hw_params(struct snd_pcm_substream *substream,
409 			    struct snd_pcm_hw_params *params,
410 			    struct snd_soc_dai *dai)
411 {
412 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
413 	struct snd_soc_device *socdev = rtd->socdev;
414 	struct snd_soc_codec *codec = socdev->card->codec;
415 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
416 	int ret;
417 	unsigned int i;
418 	unsigned int rate;
419 	unsigned int ratio;
420 	int reg;
421 
422 	/* Figure out which MCLK/LRCK ratio to use */
423 
424 	rate = params_rate(params);	/* Sampling rate, in Hz */
425 	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
426 
427 	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
428 		if (cs4270_mode_ratios[i].ratio == ratio)
429 			break;
430 	}
431 
432 	if (i == NUM_MCLK_RATIOS) {
433 		/* We did not find a matching ratio */
434 		dev_err(codec->dev, "could not find matching ratio\n");
435 		return -EINVAL;
436 	}
437 
438 	/* Set the sample rate */
439 
440 	reg = snd_soc_read(codec, CS4270_MODE);
441 	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
442 	reg |= cs4270_mode_ratios[i].mclk;
443 
444 	if (cs4270->slave_mode)
445 		reg |= CS4270_MODE_SLAVE;
446 	else
447 		reg |= cs4270_mode_ratios[i].speed_mode;
448 
449 	ret = snd_soc_write(codec, CS4270_MODE, reg);
450 	if (ret < 0) {
451 		dev_err(codec->dev, "i2c write failed\n");
452 		return ret;
453 	}
454 
455 	/* Set the DAI format */
456 
457 	reg = snd_soc_read(codec, CS4270_FORMAT);
458 	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
459 
460 	switch (cs4270->mode) {
461 	case SND_SOC_DAIFMT_I2S:
462 		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
463 		break;
464 	case SND_SOC_DAIFMT_LEFT_J:
465 		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
466 		break;
467 	default:
468 		dev_err(codec->dev, "unknown dai format\n");
469 		return -EINVAL;
470 	}
471 
472 	ret = snd_soc_write(codec, CS4270_FORMAT, reg);
473 	if (ret < 0) {
474 		dev_err(codec->dev, "i2c write failed\n");
475 		return ret;
476 	}
477 
478 	return ret;
479 }
480 
481 /**
482  * cs4270_dai_mute - enable/disable the CS4270 external mute
483  * @dai: the SOC DAI
484  * @mute: 0 = disable mute, 1 = enable mute
485  *
486  * This function toggles the mute bits in the MUTE register.  The CS4270's
487  * mute capability is intended for external muting circuitry, so if the
488  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
489  * then this function will do nothing.
490  */
491 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
492 {
493 	struct snd_soc_codec *codec = dai->codec;
494 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
495 	int reg6;
496 
497 	reg6 = snd_soc_read(codec, CS4270_MUTE);
498 
499 	if (mute)
500 		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
501 	else {
502 		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
503 		reg6 |= cs4270->manual_mute;
504 	}
505 
506 	return snd_soc_write(codec, CS4270_MUTE, reg6);
507 }
508 
509 /**
510  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
511  * 			 alsa control.
512  * @kcontrol: mixer control
513  * @ucontrol: control element information
514  *
515  * This function basically passes the arguments on to the generic
516  * snd_soc_put_volsw() function and saves the mute information in
517  * our private data structure. This is because we want to prevent
518  * cs4270_dai_mute() neglecting the user's decision to manually
519  * mute the codec's output.
520  *
521  * Returns 0 for success.
522  */
523 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
524 				struct snd_ctl_elem_value *ucontrol)
525 {
526 	struct snd_soc_codec *codec = snd_kcontrol_chip(kcontrol);
527 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
528 	int left = !ucontrol->value.integer.value[0];
529 	int right = !ucontrol->value.integer.value[1];
530 
531 	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
532 			      (right ? CS4270_MUTE_DAC_B : 0);
533 
534 	return snd_soc_put_volsw(kcontrol, ucontrol);
535 }
536 
537 /* A list of non-DAPM controls that the CS4270 supports */
538 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
539 	SOC_DOUBLE_R("Master Playback Volume",
540 		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
541 	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
542 	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
543 	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
544 	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
545 	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
546 	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
547 	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
548 	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
549 		snd_soc_get_volsw, cs4270_soc_put_mute),
550 };
551 
552 /*
553  * cs4270_codec - global variable to store codec for the ASoC probe function
554  *
555  * If struct i2c_driver had a private_data field, we wouldn't need to use
556  * cs4270_codec.  This is the only way to pass the codec structure from
557  * cs4270_i2c_probe() to cs4270_probe().  Unfortunately, there is no good
558  * way to synchronize these two functions.  cs4270_i2c_probe() can be called
559  * multiple times before cs4270_probe() is called even once.  So for now, we
560  * also only allow cs4270_i2c_probe() to be run once.  That means that we do
561  * not support more than one cs4270 device in the system, at least for now.
562  */
563 static struct snd_soc_codec *cs4270_codec;
564 
565 static struct snd_soc_dai_ops cs4270_dai_ops = {
566 	.hw_params	= cs4270_hw_params,
567 	.set_sysclk	= cs4270_set_dai_sysclk,
568 	.set_fmt	= cs4270_set_dai_fmt,
569 	.digital_mute	= cs4270_dai_mute,
570 };
571 
572 struct snd_soc_dai cs4270_dai = {
573 	.name = "cs4270",
574 	.playback = {
575 		.stream_name = "Playback",
576 		.channels_min = 1,
577 		.channels_max = 2,
578 		.rates = 0,
579 		.formats = CS4270_FORMATS,
580 	},
581 	.capture = {
582 		.stream_name = "Capture",
583 		.channels_min = 1,
584 		.channels_max = 2,
585 		.rates = 0,
586 		.formats = CS4270_FORMATS,
587 	},
588 	.ops = &cs4270_dai_ops,
589 };
590 EXPORT_SYMBOL_GPL(cs4270_dai);
591 
592 /**
593  * cs4270_probe - ASoC probe function
594  * @pdev: platform device
595  *
596  * This function is called when ASoC has all the pieces it needs to
597  * instantiate a sound driver.
598  */
599 static int cs4270_probe(struct platform_device *pdev)
600 {
601 	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
602 	struct snd_soc_codec *codec = cs4270_codec;
603 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
604 	int i, ret;
605 
606 	/* Connect the codec to the socdev.  snd_soc_new_pcms() needs this. */
607 	socdev->card->codec = codec;
608 
609 	/* Register PCMs */
610 	ret = snd_soc_new_pcms(socdev, SNDRV_DEFAULT_IDX1, SNDRV_DEFAULT_STR1);
611 	if (ret < 0) {
612 		dev_err(codec->dev, "failed to create pcms\n");
613 		return ret;
614 	}
615 
616 	/* Add the non-DAPM controls */
617 	ret = snd_soc_add_controls(codec, cs4270_snd_controls,
618 				ARRAY_SIZE(cs4270_snd_controls));
619 	if (ret < 0) {
620 		dev_err(codec->dev, "failed to add controls\n");
621 		goto error_free_pcms;
622 	}
623 
624 	/* get the power supply regulators */
625 	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
626 		cs4270->supplies[i].supply = supply_names[i];
627 
628 	ret = regulator_bulk_get(codec->dev, ARRAY_SIZE(cs4270->supplies),
629 				 cs4270->supplies);
630 	if (ret < 0)
631 		goto error_free_pcms;
632 
633 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
634 				    cs4270->supplies);
635 	if (ret < 0)
636 		goto error_free_regulators;
637 
638 	return 0;
639 
640 error_free_regulators:
641 	regulator_bulk_free(ARRAY_SIZE(cs4270->supplies),
642 			    cs4270->supplies);
643 
644 error_free_pcms:
645 	snd_soc_free_pcms(socdev);
646 
647 	return ret;
648 }
649 
650 /**
651  * cs4270_remove - ASoC remove function
652  * @pdev: platform device
653  *
654  * This function is the counterpart to cs4270_probe().
655  */
656 static int cs4270_remove(struct platform_device *pdev)
657 {
658 	struct snd_soc_device *socdev = platform_get_drvdata(pdev);
659 	struct snd_soc_codec *codec = cs4270_codec;
660 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
661 
662 	snd_soc_free_pcms(socdev);
663 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
664 	regulator_bulk_free(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
665 
666 	return 0;
667 };
668 
669 /**
670  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
671  * @i2c_client: the I2C client object
672  * @id: the I2C device ID (ignored)
673  *
674  * This function is called whenever the I2C subsystem finds a device that
675  * matches the device ID given via a prior call to i2c_add_driver().
676  */
677 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
678 	const struct i2c_device_id *id)
679 {
680 	struct snd_soc_codec *codec;
681 	struct cs4270_private *cs4270;
682 	unsigned int reg;
683 	int ret;
684 
685 	/* For now, we only support one cs4270 device in the system.  See the
686 	 * comment for cs4270_codec.
687 	 */
688 	if (cs4270_codec) {
689 		dev_err(&i2c_client->dev, "ignoring CS4270 at addr %X\n",
690 		       i2c_client->addr);
691 		dev_err(&i2c_client->dev, "only one per board allowed\n");
692 		/* Should we return something other than ENODEV here? */
693 		return -ENODEV;
694 	}
695 
696 	/* Verify that we have a CS4270 */
697 
698 	ret = i2c_smbus_read_byte_data(i2c_client, CS4270_CHIPID);
699 	if (ret < 0) {
700 		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
701 		       i2c_client->addr);
702 		return ret;
703 	}
704 	/* The top four bits of the chip ID should be 1100. */
705 	if ((ret & 0xF0) != 0xC0) {
706 		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
707 		       i2c_client->addr);
708 		return -ENODEV;
709 	}
710 
711 	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
712 		i2c_client->addr);
713 	dev_info(&i2c_client->dev, "hardware revision %X\n", ret & 0xF);
714 
715 	/* Allocate enough space for the snd_soc_codec structure
716 	   and our private data together. */
717 	cs4270 = kzalloc(sizeof(struct cs4270_private), GFP_KERNEL);
718 	if (!cs4270) {
719 		dev_err(&i2c_client->dev, "could not allocate codec\n");
720 		return -ENOMEM;
721 	}
722 	codec = &cs4270->codec;
723 
724 	mutex_init(&codec->mutex);
725 	INIT_LIST_HEAD(&codec->dapm_widgets);
726 	INIT_LIST_HEAD(&codec->dapm_paths);
727 
728 	codec->dev = &i2c_client->dev;
729 	codec->name = "CS4270";
730 	codec->owner = THIS_MODULE;
731 	codec->dai = &cs4270_dai;
732 	codec->num_dai = 1;
733 	snd_soc_codec_set_drvdata(codec, cs4270);
734 	codec->control_data = i2c_client;
735 	codec->read = cs4270_read_reg_cache;
736 	codec->write = cs4270_i2c_write;
737 	codec->reg_cache = cs4270->reg_cache;
738 	codec->reg_cache_size = CS4270_NUMREGS;
739 
740 	/* The I2C interface is set up, so pre-fill our register cache */
741 
742 	ret = cs4270_fill_cache(codec);
743 	if (ret < 0) {
744 		dev_err(&i2c_client->dev, "failed to fill register cache\n");
745 		goto error_free_codec;
746 	}
747 
748 	/* Disable auto-mute.  This feature appears to be buggy.  In some
749 	 * situations, auto-mute will not deactivate when it should, so we want
750 	 * this feature disabled by default.  An application (e.g. alsactl) can
751 	 * re-enabled it by using the controls.
752 	 */
753 
754 	reg = cs4270_read_reg_cache(codec, CS4270_MUTE);
755 	reg &= ~CS4270_MUTE_AUTO;
756 	ret = cs4270_i2c_write(codec, CS4270_MUTE, reg);
757 	if (ret < 0) {
758 		dev_err(&i2c_client->dev, "i2c write failed\n");
759 		return ret;
760 	}
761 
762 	/* Disable automatic volume control.  The hardware enables, and it
763 	 * causes volume change commands to be delayed, sometimes until after
764 	 * playback has started.  An application (e.g. alsactl) can
765 	 * re-enabled it by using the controls.
766 	 */
767 
768 	reg = cs4270_read_reg_cache(codec, CS4270_TRANS);
769 	reg &= ~(CS4270_TRANS_SOFT | CS4270_TRANS_ZERO);
770 	ret = cs4270_i2c_write(codec, CS4270_TRANS, reg);
771 	if (ret < 0) {
772 		dev_err(&i2c_client->dev, "i2c write failed\n");
773 		return ret;
774 	}
775 
776 	/* Initialize the DAI. Normally, we'd prefer to have a kmalloc'd DAI
777 	 * structure for each CS4270 device, but the machine driver needs to
778 	 * have a pointer to the DAI structure, so for now it must be a global
779 	 * variable.
780 	 */
781 	cs4270_dai.dev = &i2c_client->dev;
782 
783 	/* Register the DAI.  If all the other ASoC driver have already
784 	 * registered, then this will call our probe function, so
785 	 * cs4270_codec needs to be ready.
786 	 */
787 	cs4270_codec = codec;
788 	ret = snd_soc_register_dai(&cs4270_dai);
789 	if (ret < 0) {
790 		dev_err(&i2c_client->dev, "failed to register DAIe\n");
791 		goto error_free_codec;
792 	}
793 
794 	i2c_set_clientdata(i2c_client, cs4270);
795 
796 	return 0;
797 
798 error_free_codec:
799 	kfree(cs4270);
800 	cs4270_codec = NULL;
801 	cs4270_dai.dev = NULL;
802 
803 	return ret;
804 }
805 
806 /**
807  * cs4270_i2c_remove - remove an I2C device
808  * @i2c_client: the I2C client object
809  *
810  * This function is the counterpart to cs4270_i2c_probe().
811  */
812 static int cs4270_i2c_remove(struct i2c_client *i2c_client)
813 {
814 	struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client);
815 
816 	kfree(cs4270);
817 	cs4270_codec = NULL;
818 	cs4270_dai.dev = NULL;
819 
820 	return 0;
821 }
822 
823 /*
824  * cs4270_id - I2C device IDs supported by this driver
825  */
826 static struct i2c_device_id cs4270_id[] = {
827 	{"cs4270", 0},
828 	{}
829 };
830 MODULE_DEVICE_TABLE(i2c, cs4270_id);
831 
832 #ifdef CONFIG_PM
833 
834 /* This suspend/resume implementation can handle both - a simple standby
835  * where the codec remains powered, and a full suspend, where the voltage
836  * domain the codec is connected to is teared down and/or any other hardware
837  * reset condition is asserted.
838  *
839  * The codec's own power saving features are enabled in the suspend callback,
840  * and all registers are written back to the hardware when resuming.
841  */
842 
843 static int cs4270_soc_suspend(struct platform_device *pdev, pm_message_t mesg)
844 {
845 	struct snd_soc_codec *codec = cs4270_codec;
846 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
847 	int reg, ret;
848 
849 	reg = snd_soc_read(codec, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
850 	if (reg < 0)
851 		return reg;
852 
853 	ret = snd_soc_write(codec, CS4270_PWRCTL, reg);
854 	if (ret < 0)
855 		return ret;
856 
857 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
858 			       cs4270->supplies);
859 
860 	return 0;
861 }
862 
863 static int cs4270_soc_resume(struct platform_device *pdev)
864 {
865 	struct snd_soc_codec *codec = cs4270_codec;
866 	struct cs4270_private *cs4270 = snd_soc_codec_get_drvdata(codec);
867 	struct i2c_client *i2c_client = codec->control_data;
868 	int reg;
869 
870 	regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
871 			      cs4270->supplies);
872 
873 	/* In case the device was put to hard reset during sleep, we need to
874 	 * wait 500ns here before any I2C communication. */
875 	ndelay(500);
876 
877 	/* first restore the entire register cache ... */
878 	for (reg = CS4270_FIRSTREG; reg <= CS4270_LASTREG; reg++) {
879 		u8 val = snd_soc_read(codec, reg);
880 
881 		if (i2c_smbus_write_byte_data(i2c_client, reg, val)) {
882 			dev_err(codec->dev, "i2c write failed\n");
883 			return -EIO;
884 		}
885 	}
886 
887 	/* ... then disable the power-down bits */
888 	reg = snd_soc_read(codec, CS4270_PWRCTL);
889 	reg &= ~CS4270_PWRCTL_PDN_ALL;
890 
891 	return snd_soc_write(codec, CS4270_PWRCTL, reg);
892 }
893 #else
894 #define cs4270_soc_suspend	NULL
895 #define cs4270_soc_resume	NULL
896 #endif /* CONFIG_PM */
897 
898 /*
899  * cs4270_i2c_driver - I2C device identification
900  *
901  * This structure tells the I2C subsystem how to identify and support a
902  * given I2C device type.
903  */
904 static struct i2c_driver cs4270_i2c_driver = {
905 	.driver = {
906 		.name = "cs4270",
907 		.owner = THIS_MODULE,
908 	},
909 	.id_table = cs4270_id,
910 	.probe = cs4270_i2c_probe,
911 	.remove = cs4270_i2c_remove,
912 };
913 
914 /*
915  * ASoC codec device structure
916  *
917  * Assign this variable to the codec_dev field of the machine driver's
918  * snd_soc_device structure.
919  */
920 struct snd_soc_codec_device soc_codec_device_cs4270 = {
921 	.probe = 	cs4270_probe,
922 	.remove = 	cs4270_remove,
923 	.suspend =	cs4270_soc_suspend,
924 	.resume =	cs4270_soc_resume,
925 };
926 EXPORT_SYMBOL_GPL(soc_codec_device_cs4270);
927 
928 static int __init cs4270_init(void)
929 {
930 	pr_info("Cirrus Logic CS4270 ALSA SoC Codec Driver\n");
931 
932 	return i2c_add_driver(&cs4270_i2c_driver);
933 }
934 module_init(cs4270_init);
935 
936 static void __exit cs4270_exit(void)
937 {
938 	i2c_del_driver(&cs4270_i2c_driver);
939 }
940 module_exit(cs4270_exit);
941 
942 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
943 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
944 MODULE_LICENSE("GPL");
945