xref: /openbmc/linux/sound/soc/codecs/cs4270.c (revision c6fddb28)
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 #include <linux/gpio/consumer.h>
33 #include <linux/of_device.h>
34 
35 /*
36  * The codec isn't really big-endian or little-endian, since the I2S
37  * interface requires data to be sent serially with the MSbit first.
38  * However, to support BE and LE I2S devices, we specify both here.  That
39  * way, ALSA will always match the bit patterns.
40  */
41 #define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | \
42 			SNDRV_PCM_FMTBIT_S16_LE  | SNDRV_PCM_FMTBIT_S16_BE  | \
43 			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S18_3BE | \
44 			SNDRV_PCM_FMTBIT_S20_3LE | SNDRV_PCM_FMTBIT_S20_3BE | \
45 			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_3BE | \
46 			SNDRV_PCM_FMTBIT_S24_LE  | SNDRV_PCM_FMTBIT_S24_BE)
47 
48 /* CS4270 registers addresses */
49 #define CS4270_CHIPID	0x01	/* Chip ID */
50 #define CS4270_PWRCTL	0x02	/* Power Control */
51 #define CS4270_MODE	0x03	/* Mode Control */
52 #define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */
53 #define CS4270_TRANS	0x05	/* Transition Control */
54 #define CS4270_MUTE	0x06	/* Mute Control */
55 #define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */
56 #define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */
57 
58 #define CS4270_FIRSTREG	0x01
59 #define CS4270_LASTREG	0x08
60 #define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)
61 #define CS4270_I2C_INCR	0x80
62 
63 /* Bit masks for the CS4270 registers */
64 #define CS4270_CHIPID_ID	0xF0
65 #define CS4270_CHIPID_REV	0x0F
66 #define CS4270_PWRCTL_FREEZE	0x80
67 #define CS4270_PWRCTL_PDN_ADC	0x20
68 #define CS4270_PWRCTL_PDN_DAC	0x02
69 #define CS4270_PWRCTL_PDN	0x01
70 #define CS4270_PWRCTL_PDN_ALL	\
71 	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)
72 #define CS4270_MODE_SPEED_MASK	0x30
73 #define CS4270_MODE_1X		0x00
74 #define CS4270_MODE_2X		0x10
75 #define CS4270_MODE_4X		0x20
76 #define CS4270_MODE_SLAVE	0x30
77 #define CS4270_MODE_DIV_MASK	0x0E
78 #define CS4270_MODE_DIV1	0x00
79 #define CS4270_MODE_DIV15	0x02
80 #define CS4270_MODE_DIV2	0x04
81 #define CS4270_MODE_DIV3	0x06
82 #define CS4270_MODE_DIV4	0x08
83 #define CS4270_MODE_POPGUARD	0x01
84 #define CS4270_FORMAT_FREEZE_A	0x80
85 #define CS4270_FORMAT_FREEZE_B	0x40
86 #define CS4270_FORMAT_LOOPBACK	0x20
87 #define CS4270_FORMAT_DAC_MASK	0x18
88 #define CS4270_FORMAT_DAC_LJ	0x00
89 #define CS4270_FORMAT_DAC_I2S	0x08
90 #define CS4270_FORMAT_DAC_RJ16	0x18
91 #define CS4270_FORMAT_DAC_RJ24	0x10
92 #define CS4270_FORMAT_ADC_MASK	0x01
93 #define CS4270_FORMAT_ADC_LJ	0x00
94 #define CS4270_FORMAT_ADC_I2S	0x01
95 #define CS4270_TRANS_ONE_VOL	0x80
96 #define CS4270_TRANS_SOFT	0x40
97 #define CS4270_TRANS_ZERO	0x20
98 #define CS4270_TRANS_INV_ADC_A	0x08
99 #define CS4270_TRANS_INV_ADC_B	0x10
100 #define CS4270_TRANS_INV_DAC_A	0x02
101 #define CS4270_TRANS_INV_DAC_B	0x04
102 #define CS4270_TRANS_DEEMPH	0x01
103 #define CS4270_MUTE_AUTO	0x20
104 #define CS4270_MUTE_ADC_A	0x08
105 #define CS4270_MUTE_ADC_B	0x10
106 #define CS4270_MUTE_POLARITY	0x04
107 #define CS4270_MUTE_DAC_A	0x01
108 #define CS4270_MUTE_DAC_B	0x02
109 
110 /* Power-on default values for the registers
111  *
112  * This array contains the power-on default values of the registers, with the
113  * exception of the "CHIPID" register (01h).  The lower four bits of that
114  * register contain the hardware revision, so it is treated as volatile.
115  */
116 static const struct reg_default cs4270_reg_defaults[] = {
117 	{ 2, 0x00 },
118 	{ 3, 0x30 },
119 	{ 4, 0x00 },
120 	{ 5, 0x60 },
121 	{ 6, 0x20 },
122 	{ 7, 0x00 },
123 	{ 8, 0x00 },
124 };
125 
126 static const char *supply_names[] = {
127 	"va", "vd", "vlc"
128 };
129 
130 /* Private data for the CS4270 */
131 struct cs4270_private {
132 	struct regmap *regmap;
133 	unsigned int mclk; /* Input frequency of the MCLK pin */
134 	unsigned int mode; /* The mode (I2S or left-justified) */
135 	unsigned int slave_mode;
136 	unsigned int manual_mute;
137 
138 	/* power domain regulators */
139 	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];
140 
141 	/* reset gpio */
142 	struct gpio_desc *reset_gpio;
143 };
144 
145 static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {
146 SND_SOC_DAPM_INPUT("AINL"),
147 SND_SOC_DAPM_INPUT("AINR"),
148 
149 SND_SOC_DAPM_OUTPUT("AOUTL"),
150 SND_SOC_DAPM_OUTPUT("AOUTR"),
151 };
152 
153 static const struct snd_soc_dapm_route cs4270_dapm_routes[] = {
154 	{ "Capture", NULL, "AINL" },
155 	{ "Capture", NULL, "AINR" },
156 
157 	{ "AOUTL", NULL, "Playback" },
158 	{ "AOUTR", NULL, "Playback" },
159 };
160 
161 /**
162  * struct cs4270_mode_ratios - clock ratio tables
163  * @ratio: the ratio of MCLK to the sample rate
164  * @speed_mode: the Speed Mode bits to set in the Mode Control register for
165  *              this ratio
166  * @mclk: the Ratio Select bits to set in the Mode Control register for this
167  *        ratio
168  *
169  * The data for this chart is taken from Table 5 of the CS4270 reference
170  * manual.
171  *
172  * This table is used to determine how to program the Mode Control register.
173  * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling
174  * rates the CS4270 currently supports.
175  *
176  * @speed_mode is the corresponding bit pattern to be written to the
177  * MODE bits of the Mode Control Register
178  *
179  * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of
180  * the Mode Control Register.
181  *
182  * In situations where a single ratio is represented by multiple speed
183  * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick
184  * double-speed instead of quad-speed.  However, the CS4270 errata states
185  * that divide-By-1.5 can cause failures, so we avoid that mode where
186  * possible.
187  *
188  * Errata: There is an errata for the CS4270 where divide-by-1.5 does not
189  * work if Vd is 3.3V.  If this effects you, select the
190  * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will
191  * never select any sample rates that require divide-by-1.5.
192  */
193 struct cs4270_mode_ratios {
194 	unsigned int ratio;
195 	u8 speed_mode;
196 	u8 mclk;
197 };
198 
199 static struct cs4270_mode_ratios cs4270_mode_ratios[] = {
200 	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},
201 #ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA
202 	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},
203 #endif
204 	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},
205 	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},
206 	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},
207 	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},
208 	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},
209 	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},
210 	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}
211 };
212 
213 /* The number of MCLK/LRCK ratios supported by the CS4270 */
214 #define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)
215 
216 static bool cs4270_reg_is_readable(struct device *dev, unsigned int reg)
217 {
218 	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);
219 }
220 
221 static bool cs4270_reg_is_volatile(struct device *dev, unsigned int reg)
222 {
223 	/* Unreadable registers are considered volatile */
224 	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
225 		return true;
226 
227 	return reg == CS4270_CHIPID;
228 }
229 
230 /**
231  * cs4270_set_dai_sysclk - determine the CS4270 samples rates.
232  * @codec_dai: the codec DAI
233  * @clk_id: the clock ID (ignored)
234  * @freq: the MCLK input frequency
235  * @dir: the clock direction (ignored)
236  *
237  * This function is used to tell the codec driver what the input MCLK
238  * frequency is.
239  *
240  * The value of MCLK is used to determine which sample rates are supported
241  * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine
242  * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.
243  *
244  * This function calculates the nine ratios and determines which ones match
245  * a standard sample rate.  If there's a match, then it is added to the list
246  * of supported sample rates.
247  *
248  * This function must be called by the machine driver's 'startup' function,
249  * otherwise the list of supported sample rates will not be available in
250  * time for ALSA.
251  *
252  * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause
253  * theoretically possible sample rates to be enabled. Call it again with a
254  * proper value set one the external clock is set (most probably you would do
255  * that from a machine's driver 'hw_param' hook.
256  */
257 static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,
258 				 int clk_id, unsigned int freq, int dir)
259 {
260 	struct snd_soc_component *component = codec_dai->component;
261 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
262 
263 	cs4270->mclk = freq;
264 	return 0;
265 }
266 
267 /**
268  * cs4270_set_dai_fmt - configure the codec for the selected audio format
269  * @codec_dai: the codec DAI
270  * @format: a SND_SOC_DAIFMT_x value indicating the data format
271  *
272  * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the
273  * codec accordingly.
274  *
275  * Currently, this function only supports SND_SOC_DAIFMT_I2S and
276  * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified
277  * data for playback only, but ASoC currently does not support different
278  * formats for playback vs. record.
279  */
280 static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,
281 			      unsigned int format)
282 {
283 	struct snd_soc_component *component = codec_dai->component;
284 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
285 
286 	/* set DAI format */
287 	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {
288 	case SND_SOC_DAIFMT_I2S:
289 	case SND_SOC_DAIFMT_LEFT_J:
290 		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;
291 		break;
292 	default:
293 		dev_err(component->dev, "invalid dai format\n");
294 		return -EINVAL;
295 	}
296 
297 	/* set master/slave audio interface */
298 	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {
299 	case SND_SOC_DAIFMT_CBS_CFS:
300 		cs4270->slave_mode = 1;
301 		break;
302 	case SND_SOC_DAIFMT_CBM_CFM:
303 		cs4270->slave_mode = 0;
304 		break;
305 	default:
306 		/* all other modes are unsupported by the hardware */
307 		dev_err(component->dev, "Unknown master/slave configuration\n");
308 		return -EINVAL;
309 	}
310 
311 	return 0;
312 }
313 
314 /**
315  * cs4270_hw_params - program the CS4270 with the given hardware parameters.
316  * @substream: the audio stream
317  * @params: the hardware parameters to set
318  * @dai: the SOC DAI (ignored)
319  *
320  * This function programs the hardware with the values provided.
321  * Specifically, the sample rate and the data format.
322  *
323  * The .ops functions are used to provide board-specific data, like input
324  * frequencies, to this driver.  This function takes that information,
325  * combines it with the hardware parameters provided, and programs the
326  * hardware accordingly.
327  */
328 static int cs4270_hw_params(struct snd_pcm_substream *substream,
329 			    struct snd_pcm_hw_params *params,
330 			    struct snd_soc_dai *dai)
331 {
332 	struct snd_soc_component *component = dai->component;
333 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
334 	int ret;
335 	unsigned int i;
336 	unsigned int rate;
337 	unsigned int ratio;
338 	int reg;
339 
340 	/* Figure out which MCLK/LRCK ratio to use */
341 
342 	rate = params_rate(params);	/* Sampling rate, in Hz */
343 	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */
344 
345 	for (i = 0; i < NUM_MCLK_RATIOS; i++) {
346 		if (cs4270_mode_ratios[i].ratio == ratio)
347 			break;
348 	}
349 
350 	if (i == NUM_MCLK_RATIOS) {
351 		/* We did not find a matching ratio */
352 		dev_err(component->dev, "could not find matching ratio\n");
353 		return -EINVAL;
354 	}
355 
356 	/* Set the sample rate */
357 
358 	reg = snd_soc_component_read32(component, CS4270_MODE);
359 	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);
360 	reg |= cs4270_mode_ratios[i].mclk;
361 
362 	if (cs4270->slave_mode)
363 		reg |= CS4270_MODE_SLAVE;
364 	else
365 		reg |= cs4270_mode_ratios[i].speed_mode;
366 
367 	ret = snd_soc_component_write(component, CS4270_MODE, reg);
368 	if (ret < 0) {
369 		dev_err(component->dev, "i2c write failed\n");
370 		return ret;
371 	}
372 
373 	/* Set the DAI format */
374 
375 	reg = snd_soc_component_read32(component, CS4270_FORMAT);
376 	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);
377 
378 	switch (cs4270->mode) {
379 	case SND_SOC_DAIFMT_I2S:
380 		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;
381 		break;
382 	case SND_SOC_DAIFMT_LEFT_J:
383 		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;
384 		break;
385 	default:
386 		dev_err(component->dev, "unknown dai format\n");
387 		return -EINVAL;
388 	}
389 
390 	ret = snd_soc_component_write(component, CS4270_FORMAT, reg);
391 	if (ret < 0) {
392 		dev_err(component->dev, "i2c write failed\n");
393 		return ret;
394 	}
395 
396 	return ret;
397 }
398 
399 /**
400  * cs4270_dai_mute - enable/disable the CS4270 external mute
401  * @dai: the SOC DAI
402  * @mute: 0 = disable mute, 1 = enable mute
403  *
404  * This function toggles the mute bits in the MUTE register.  The CS4270's
405  * mute capability is intended for external muting circuitry, so if the
406  * board does not have the MUTEA or MUTEB pins connected to such circuitry,
407  * then this function will do nothing.
408  */
409 static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute)
410 {
411 	struct snd_soc_component *component = dai->component;
412 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
413 	int reg6;
414 
415 	reg6 = snd_soc_component_read32(component, CS4270_MUTE);
416 
417 	if (mute)
418 		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;
419 	else {
420 		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);
421 		reg6 |= cs4270->manual_mute;
422 	}
423 
424 	return snd_soc_component_write(component, CS4270_MUTE, reg6);
425 }
426 
427 /**
428  * cs4270_soc_put_mute - put callback for the 'Master Playback switch'
429  * 			 alsa control.
430  * @kcontrol: mixer control
431  * @ucontrol: control element information
432  *
433  * This function basically passes the arguments on to the generic
434  * snd_soc_put_volsw() function and saves the mute information in
435  * our private data structure. This is because we want to prevent
436  * cs4270_dai_mute() neglecting the user's decision to manually
437  * mute the codec's output.
438  *
439  * Returns 0 for success.
440  */
441 static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,
442 				struct snd_ctl_elem_value *ucontrol)
443 {
444 	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);
445 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
446 	int left = !ucontrol->value.integer.value[0];
447 	int right = !ucontrol->value.integer.value[1];
448 
449 	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |
450 			      (right ? CS4270_MUTE_DAC_B : 0);
451 
452 	return snd_soc_put_volsw(kcontrol, ucontrol);
453 }
454 
455 /* A list of non-DAPM controls that the CS4270 supports */
456 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
457 	SOC_DOUBLE_R("Master Playback Volume",
458 		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),
459 	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),
460 	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),
461 	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),
462 	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),
463 	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),
464 	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),
465 	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),
466 	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,
467 		snd_soc_get_volsw, cs4270_soc_put_mute),
468 };
469 
470 static const struct snd_soc_dai_ops cs4270_dai_ops = {
471 	.hw_params	= cs4270_hw_params,
472 	.set_sysclk	= cs4270_set_dai_sysclk,
473 	.set_fmt	= cs4270_set_dai_fmt,
474 	.digital_mute	= cs4270_dai_mute,
475 };
476 
477 static struct snd_soc_dai_driver cs4270_dai = {
478 	.name = "cs4270-hifi",
479 	.playback = {
480 		.stream_name = "Playback",
481 		.channels_min = 2,
482 		.channels_max = 2,
483 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
484 		.rate_min = 4000,
485 		.rate_max = 216000,
486 		.formats = CS4270_FORMATS,
487 	},
488 	.capture = {
489 		.stream_name = "Capture",
490 		.channels_min = 2,
491 		.channels_max = 2,
492 		.rates = SNDRV_PCM_RATE_CONTINUOUS,
493 		.rate_min = 4000,
494 		.rate_max = 216000,
495 		.formats = CS4270_FORMATS,
496 	},
497 	.ops = &cs4270_dai_ops,
498 };
499 
500 /**
501  * cs4270_probe - ASoC probe function
502  * @pdev: platform device
503  *
504  * This function is called when ASoC has all the pieces it needs to
505  * instantiate a sound driver.
506  */
507 static int cs4270_probe(struct snd_soc_component *component)
508 {
509 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
510 	int ret;
511 
512 	/* Disable auto-mute.  This feature appears to be buggy.  In some
513 	 * situations, auto-mute will not deactivate when it should, so we want
514 	 * this feature disabled by default.  An application (e.g. alsactl) can
515 	 * re-enabled it by using the controls.
516 	 */
517 	ret = snd_soc_component_update_bits(component, CS4270_MUTE, CS4270_MUTE_AUTO, 0);
518 	if (ret < 0) {
519 		dev_err(component->dev, "i2c write failed\n");
520 		return ret;
521 	}
522 
523 	/* Disable automatic volume control.  The hardware enables, and it
524 	 * causes volume change commands to be delayed, sometimes until after
525 	 * playback has started.  An application (e.g. alsactl) can
526 	 * re-enabled it by using the controls.
527 	 */
528 	ret = snd_soc_component_update_bits(component, CS4270_TRANS,
529 		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);
530 	if (ret < 0) {
531 		dev_err(component->dev, "i2c write failed\n");
532 		return ret;
533 	}
534 
535 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
536 				    cs4270->supplies);
537 
538 	return ret;
539 }
540 
541 /**
542  * cs4270_remove - ASoC remove function
543  * @pdev: platform device
544  *
545  * This function is the counterpart to cs4270_probe().
546  */
547 static void cs4270_remove(struct snd_soc_component *component)
548 {
549 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
550 
551 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);
552 };
553 
554 #ifdef CONFIG_PM
555 
556 /* This suspend/resume implementation can handle both - a simple standby
557  * where the codec remains powered, and a full suspend, where the voltage
558  * domain the codec is connected to is teared down and/or any other hardware
559  * reset condition is asserted.
560  *
561  * The codec's own power saving features are enabled in the suspend callback,
562  * and all registers are written back to the hardware when resuming.
563  */
564 
565 static int cs4270_soc_suspend(struct snd_soc_component *component)
566 {
567 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
568 	int reg, ret;
569 
570 	reg = snd_soc_component_read32(component, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;
571 	if (reg < 0)
572 		return reg;
573 
574 	ret = snd_soc_component_write(component, CS4270_PWRCTL, reg);
575 	if (ret < 0)
576 		return ret;
577 
578 	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),
579 			       cs4270->supplies);
580 
581 	return 0;
582 }
583 
584 static int cs4270_soc_resume(struct snd_soc_component *component)
585 {
586 	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);
587 	int reg, ret;
588 
589 	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),
590 				    cs4270->supplies);
591 	if (ret != 0)
592 		return ret;
593 
594 	/* In case the device was put to hard reset during sleep, we need to
595 	 * wait 500ns here before any I2C communication. */
596 	ndelay(500);
597 
598 	/* first restore the entire register cache ... */
599 	regcache_sync(cs4270->regmap);
600 
601 	/* ... then disable the power-down bits */
602 	reg = snd_soc_component_read32(component, CS4270_PWRCTL);
603 	reg &= ~CS4270_PWRCTL_PDN_ALL;
604 
605 	return snd_soc_component_write(component, CS4270_PWRCTL, reg);
606 }
607 #else
608 #define cs4270_soc_suspend	NULL
609 #define cs4270_soc_resume	NULL
610 #endif /* CONFIG_PM */
611 
612 /*
613  * ASoC codec driver structure
614  */
615 static const struct snd_soc_component_driver soc_component_device_cs4270 = {
616 	.probe			= cs4270_probe,
617 	.remove			= cs4270_remove,
618 	.suspend		= cs4270_soc_suspend,
619 	.resume			= cs4270_soc_resume,
620 	.controls		= cs4270_snd_controls,
621 	.num_controls		= ARRAY_SIZE(cs4270_snd_controls),
622 	.dapm_widgets		= cs4270_dapm_widgets,
623 	.num_dapm_widgets	= ARRAY_SIZE(cs4270_dapm_widgets),
624 	.dapm_routes		= cs4270_dapm_routes,
625 	.num_dapm_routes	= ARRAY_SIZE(cs4270_dapm_routes),
626 	.idle_bias_on		= 1,
627 	.use_pmdown_time	= 1,
628 	.endianness		= 1,
629 	.non_legacy_dai_naming	= 1,
630 };
631 
632 /*
633  * cs4270_of_match - the device tree bindings
634  */
635 static const struct of_device_id cs4270_of_match[] = {
636 	{ .compatible = "cirrus,cs4270", },
637 	{ }
638 };
639 MODULE_DEVICE_TABLE(of, cs4270_of_match);
640 
641 static const struct regmap_config cs4270_regmap = {
642 	.reg_bits =		8,
643 	.val_bits =		8,
644 	.max_register =		CS4270_LASTREG,
645 	.reg_defaults =		cs4270_reg_defaults,
646 	.num_reg_defaults =	ARRAY_SIZE(cs4270_reg_defaults),
647 	.cache_type =		REGCACHE_RBTREE,
648 	.write_flag_mask =	CS4270_I2C_INCR,
649 
650 	.readable_reg =		cs4270_reg_is_readable,
651 	.volatile_reg =		cs4270_reg_is_volatile,
652 };
653 
654 /**
655  * cs4270_i2c_remove - deinitialize the I2C interface of the CS4270
656  * @i2c_client: the I2C client object
657  *
658  * This function puts the chip into low power mode when the i2c device
659  * is removed.
660  */
661 static int cs4270_i2c_remove(struct i2c_client *i2c_client)
662 {
663 	struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client);
664 
665 	gpiod_set_value_cansleep(cs4270->reset_gpio, 0);
666 
667 	return 0;
668 }
669 
670 /**
671  * cs4270_i2c_probe - initialize the I2C interface of the CS4270
672  * @i2c_client: the I2C client object
673  * @id: the I2C device ID (ignored)
674  *
675  * This function is called whenever the I2C subsystem finds a device that
676  * matches the device ID given via a prior call to i2c_add_driver().
677  */
678 static int cs4270_i2c_probe(struct i2c_client *i2c_client,
679 	const struct i2c_device_id *id)
680 {
681 	struct cs4270_private *cs4270;
682 	unsigned int val;
683 	int ret, i;
684 
685 	cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),
686 			      GFP_KERNEL);
687 	if (!cs4270)
688 		return -ENOMEM;
689 
690 	/* get the power supply regulators */
691 	for (i = 0; i < ARRAY_SIZE(supply_names); i++)
692 		cs4270->supplies[i].supply = supply_names[i];
693 
694 	ret = devm_regulator_bulk_get(&i2c_client->dev,
695 				      ARRAY_SIZE(cs4270->supplies),
696 				      cs4270->supplies);
697 	if (ret < 0)
698 		return ret;
699 
700 	/* reset the device */
701 	cs4270->reset_gpio = devm_gpiod_get_optional(&i2c_client->dev, "reset",
702 						     GPIOD_OUT_LOW);
703 	if (IS_ERR(cs4270->reset_gpio)) {
704 		dev_dbg(&i2c_client->dev, "Error getting CS4270 reset GPIO\n");
705 		return PTR_ERR(cs4270->reset_gpio);
706 	}
707 
708 	if (cs4270->reset_gpio) {
709 		dev_dbg(&i2c_client->dev, "Found reset GPIO\n");
710 		gpiod_set_value_cansleep(cs4270->reset_gpio, 1);
711 	}
712 
713 	/* Sleep 500ns before i2c communications */
714 	ndelay(500);
715 
716 	cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);
717 	if (IS_ERR(cs4270->regmap))
718 		return PTR_ERR(cs4270->regmap);
719 
720 	/* Verify that we have a CS4270 */
721 	ret = regmap_read(cs4270->regmap, CS4270_CHIPID, &val);
722 	if (ret < 0) {
723 		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",
724 		       i2c_client->addr);
725 		return ret;
726 	}
727 	/* The top four bits of the chip ID should be 1100. */
728 	if ((val & 0xF0) != 0xC0) {
729 		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",
730 		       i2c_client->addr);
731 		return -ENODEV;
732 	}
733 
734 	dev_info(&i2c_client->dev, "found device at i2c address %X\n",
735 		i2c_client->addr);
736 	dev_info(&i2c_client->dev, "hardware revision %X\n", val & 0xF);
737 
738 	i2c_set_clientdata(i2c_client, cs4270);
739 
740 	ret = devm_snd_soc_register_component(&i2c_client->dev,
741 			&soc_component_device_cs4270, &cs4270_dai, 1);
742 	return ret;
743 }
744 
745 /*
746  * cs4270_id - I2C device IDs supported by this driver
747  */
748 static const struct i2c_device_id cs4270_id[] = {
749 	{"cs4270", 0},
750 	{}
751 };
752 MODULE_DEVICE_TABLE(i2c, cs4270_id);
753 
754 /*
755  * cs4270_i2c_driver - I2C device identification
756  *
757  * This structure tells the I2C subsystem how to identify and support a
758  * given I2C device type.
759  */
760 static struct i2c_driver cs4270_i2c_driver = {
761 	.driver = {
762 		.name = "cs4270",
763 		.of_match_table = cs4270_of_match,
764 	},
765 	.id_table = cs4270_id,
766 	.probe = cs4270_i2c_probe,
767 	.remove = cs4270_i2c_remove,
768 };
769 
770 module_i2c_driver(cs4270_i2c_driver);
771 
772 MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");
773 MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");
774 MODULE_LICENSE("GPL");
775