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1/*2 * CS4270 ALSA SoC (ASoC) codec driver3 *4 * Author: Timur Tabi <timur@freescale.com>5 *6 * Copyright 2007-2009 Freescale Semiconductor, Inc.  This file is licensed7 * under the terms of the GNU General Public License version 2.  This8 * program is licensed "as is" without any warranty of any kind, whether9 * 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 SPI17 * - Support for master and slave mode18 * - The machine driver's 'startup' function must call19 *   cs4270_set_dai_sysclk() with the value of MCLK.20 * - Only I2S and left-justified modes are supported21 * - Power management is supported22 */23 24#include <linux/mod_devicetable.h>25#include <linux/module.h>26#include <linux/slab.h>27#include <sound/core.h>28#include <sound/soc.h>29#include <sound/initval.h>30#include <linux/i2c.h>31#include <linux/delay.h>32#include <linux/regulator/consumer.h>33#include <linux/gpio/consumer.h>34 35#define CS4270_FORMATS (SNDRV_PCM_FMTBIT_S8      | SNDRV_PCM_FMTBIT_S16_LE  | \36			SNDRV_PCM_FMTBIT_S18_3LE | SNDRV_PCM_FMTBIT_S20_3LE | \37			SNDRV_PCM_FMTBIT_S24_3LE | SNDRV_PCM_FMTBIT_S24_LE)38 39/* CS4270 registers addresses */40#define CS4270_CHIPID	0x01	/* Chip ID */41#define CS4270_PWRCTL	0x02	/* Power Control */42#define CS4270_MODE	0x03	/* Mode Control */43#define CS4270_FORMAT	0x04	/* Serial Format, ADC/DAC Control */44#define CS4270_TRANS	0x05	/* Transition Control */45#define CS4270_MUTE	0x06	/* Mute Control */46#define CS4270_VOLA	0x07	/* DAC Channel A Volume Control */47#define CS4270_VOLB	0x08	/* DAC Channel B Volume Control */48 49#define CS4270_FIRSTREG	0x0150#define CS4270_LASTREG	0x0851#define CS4270_NUMREGS	(CS4270_LASTREG - CS4270_FIRSTREG + 1)52#define CS4270_I2C_INCR	0x8053 54/* Bit masks for the CS4270 registers */55#define CS4270_CHIPID_ID	0xF056#define CS4270_CHIPID_REV	0x0F57#define CS4270_PWRCTL_FREEZE	0x8058#define CS4270_PWRCTL_PDN_ADC	0x2059#define CS4270_PWRCTL_PDN_DAC	0x0260#define CS4270_PWRCTL_PDN	0x0161#define CS4270_PWRCTL_PDN_ALL	\62	(CS4270_PWRCTL_PDN_ADC | CS4270_PWRCTL_PDN_DAC | CS4270_PWRCTL_PDN)63#define CS4270_MODE_SPEED_MASK	0x3064#define CS4270_MODE_1X		0x0065#define CS4270_MODE_2X		0x1066#define CS4270_MODE_4X		0x2067#define CS4270_MODE_SLAVE	0x3068#define CS4270_MODE_DIV_MASK	0x0E69#define CS4270_MODE_DIV1	0x0070#define CS4270_MODE_DIV15	0x0271#define CS4270_MODE_DIV2	0x0472#define CS4270_MODE_DIV3	0x0673#define CS4270_MODE_DIV4	0x0874#define CS4270_MODE_POPGUARD	0x0175#define CS4270_FORMAT_FREEZE_A	0x8076#define CS4270_FORMAT_FREEZE_B	0x4077#define CS4270_FORMAT_LOOPBACK	0x2078#define CS4270_FORMAT_DAC_MASK	0x1879#define CS4270_FORMAT_DAC_LJ	0x0080#define CS4270_FORMAT_DAC_I2S	0x0881#define CS4270_FORMAT_DAC_RJ16	0x1882#define CS4270_FORMAT_DAC_RJ24	0x1083#define CS4270_FORMAT_ADC_MASK	0x0184#define CS4270_FORMAT_ADC_LJ	0x0085#define CS4270_FORMAT_ADC_I2S	0x0186#define CS4270_TRANS_ONE_VOL	0x8087#define CS4270_TRANS_SOFT	0x4088#define CS4270_TRANS_ZERO	0x2089#define CS4270_TRANS_INV_ADC_A	0x0890#define CS4270_TRANS_INV_ADC_B	0x1091#define CS4270_TRANS_INV_DAC_A	0x0292#define CS4270_TRANS_INV_DAC_B	0x0493#define CS4270_TRANS_DEEMPH	0x0194#define CS4270_MUTE_AUTO	0x2095#define CS4270_MUTE_ADC_A	0x0896#define CS4270_MUTE_ADC_B	0x1097#define CS4270_MUTE_POLARITY	0x0498#define CS4270_MUTE_DAC_A	0x0199#define CS4270_MUTE_DAC_B	0x02100 101/* Power-on default values for the registers102 *103 * This array contains the power-on default values of the registers, with the104 * exception of the "CHIPID" register (01h).  The lower four bits of that105 * register contain the hardware revision, so it is treated as volatile.106 */107static const struct reg_default cs4270_reg_defaults[] = {108	{ 2, 0x00 },109	{ 3, 0x30 },110	{ 4, 0x00 },111	{ 5, 0x60 },112	{ 6, 0x20 },113	{ 7, 0x00 },114	{ 8, 0x00 },115};116 117static const char *supply_names[] = {118	"va", "vd", "vlc"119};120 121/* Private data for the CS4270 */122struct cs4270_private {123	struct regmap *regmap;124	unsigned int mclk; /* Input frequency of the MCLK pin */125	unsigned int mode; /* The mode (I2S or left-justified) */126	unsigned int slave_mode;127	unsigned int manual_mute;128 129	/* power domain regulators */130	struct regulator_bulk_data supplies[ARRAY_SIZE(supply_names)];131 132	/* reset gpio */133	struct gpio_desc *reset_gpio;134};135 136static const struct snd_soc_dapm_widget cs4270_dapm_widgets[] = {137SND_SOC_DAPM_INPUT("AINL"),138SND_SOC_DAPM_INPUT("AINR"),139 140SND_SOC_DAPM_OUTPUT("AOUTL"),141SND_SOC_DAPM_OUTPUT("AOUTR"),142};143 144static const struct snd_soc_dapm_route cs4270_dapm_routes[] = {145	{ "Capture", NULL, "AINL" },146	{ "Capture", NULL, "AINR" },147 148	{ "AOUTL", NULL, "Playback" },149	{ "AOUTR", NULL, "Playback" },150};151 152/**153 * struct cs4270_mode_ratios - clock ratio tables154 * @ratio: the ratio of MCLK to the sample rate155 * @speed_mode: the Speed Mode bits to set in the Mode Control register for156 *              this ratio157 * @mclk: the Ratio Select bits to set in the Mode Control register for this158 *        ratio159 *160 * The data for this chart is taken from Table 5 of the CS4270 reference161 * manual.162 *163 * This table is used to determine how to program the Mode Control register.164 * It is also used by cs4270_set_dai_sysclk() to tell ALSA which sampling165 * rates the CS4270 currently supports.166 *167 * @speed_mode is the corresponding bit pattern to be written to the168 * MODE bits of the Mode Control Register169 *170 * @mclk is the corresponding bit pattern to be wirten to the MCLK bits of171 * the Mode Control Register.172 *173 * In situations where a single ratio is represented by multiple speed174 * modes, we favor the slowest speed.  E.g, for a ratio of 128, we pick175 * double-speed instead of quad-speed.  However, the CS4270 errata states176 * that divide-By-1.5 can cause failures, so we avoid that mode where177 * possible.178 *179 * Errata: There is an errata for the CS4270 where divide-by-1.5 does not180 * work if Vd is 3.3V.  If this effects you, select the181 * CONFIG_SND_SOC_CS4270_VD33_ERRATA Kconfig option, and the driver will182 * never select any sample rates that require divide-by-1.5.183 */184struct cs4270_mode_ratios {185	unsigned int ratio;186	u8 speed_mode;187	u8 mclk;188};189 190static struct cs4270_mode_ratios cs4270_mode_ratios[] = {191	{64, CS4270_MODE_4X, CS4270_MODE_DIV1},192#ifndef CONFIG_SND_SOC_CS4270_VD33_ERRATA193	{96, CS4270_MODE_4X, CS4270_MODE_DIV15},194#endif195	{128, CS4270_MODE_2X, CS4270_MODE_DIV1},196	{192, CS4270_MODE_4X, CS4270_MODE_DIV3},197	{256, CS4270_MODE_1X, CS4270_MODE_DIV1},198	{384, CS4270_MODE_2X, CS4270_MODE_DIV3},199	{512, CS4270_MODE_1X, CS4270_MODE_DIV2},200	{768, CS4270_MODE_1X, CS4270_MODE_DIV3},201	{1024, CS4270_MODE_1X, CS4270_MODE_DIV4}202};203 204/* The number of MCLK/LRCK ratios supported by the CS4270 */205#define NUM_MCLK_RATIOS		ARRAY_SIZE(cs4270_mode_ratios)206 207static bool cs4270_reg_is_readable(struct device *dev, unsigned int reg)208{209	return (reg >= CS4270_FIRSTREG) && (reg <= CS4270_LASTREG);210}211 212static bool cs4270_reg_is_volatile(struct device *dev, unsigned int reg)213{214	/* Unreadable registers are considered volatile */215	if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))216		return true;217 218	return reg == CS4270_CHIPID;219}220 221/**222 * cs4270_set_dai_sysclk - determine the CS4270 samples rates.223 * @codec_dai: the codec DAI224 * @clk_id: the clock ID (ignored)225 * @freq: the MCLK input frequency226 * @dir: the clock direction (ignored)227 *228 * This function is used to tell the codec driver what the input MCLK229 * frequency is.230 *231 * The value of MCLK is used to determine which sample rates are supported232 * by the CS4270.  The ratio of MCLK / Fs must be equal to one of nine233 * supported values - 64, 96, 128, 192, 256, 384, 512, 768, and 1024.234 *235 * This function calculates the nine ratios and determines which ones match236 * a standard sample rate.  If there's a match, then it is added to the list237 * of supported sample rates.238 *239 * This function must be called by the machine driver's 'startup' function,240 * otherwise the list of supported sample rates will not be available in241 * time for ALSA.242 *243 * For setups with variable MCLKs, pass 0 as 'freq' argument. This will cause244 * theoretically possible sample rates to be enabled. Call it again with a245 * proper value set one the external clock is set (most probably you would do246 * that from a machine's driver 'hw_param' hook.247 */248static int cs4270_set_dai_sysclk(struct snd_soc_dai *codec_dai,249				 int clk_id, unsigned int freq, int dir)250{251	struct snd_soc_component *component = codec_dai->component;252	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);253 254	cs4270->mclk = freq;255	return 0;256}257 258/**259 * cs4270_set_dai_fmt - configure the codec for the selected audio format260 * @codec_dai: the codec DAI261 * @format: a SND_SOC_DAIFMT_x value indicating the data format262 *263 * This function takes a bitmask of SND_SOC_DAIFMT_x bits and programs the264 * codec accordingly.265 *266 * Currently, this function only supports SND_SOC_DAIFMT_I2S and267 * SND_SOC_DAIFMT_LEFT_J.  The CS4270 codec also supports right-justified268 * data for playback only, but ASoC currently does not support different269 * formats for playback vs. record.270 */271static int cs4270_set_dai_fmt(struct snd_soc_dai *codec_dai,272			      unsigned int format)273{274	struct snd_soc_component *component = codec_dai->component;275	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);276 277	/* set DAI format */278	switch (format & SND_SOC_DAIFMT_FORMAT_MASK) {279	case SND_SOC_DAIFMT_I2S:280	case SND_SOC_DAIFMT_LEFT_J:281		cs4270->mode = format & SND_SOC_DAIFMT_FORMAT_MASK;282		break;283	default:284		dev_err(component->dev, "invalid dai format\n");285		return -EINVAL;286	}287 288	/* set master/slave audio interface */289	switch (format & SND_SOC_DAIFMT_MASTER_MASK) {290	case SND_SOC_DAIFMT_CBS_CFS:291		cs4270->slave_mode = 1;292		break;293	case SND_SOC_DAIFMT_CBM_CFM:294		cs4270->slave_mode = 0;295		break;296	default:297		/* all other modes are unsupported by the hardware */298		dev_err(component->dev, "Unknown master/slave configuration\n");299		return -EINVAL;300	}301 302	return 0;303}304 305/**306 * cs4270_hw_params - program the CS4270 with the given hardware parameters.307 * @substream: the audio stream308 * @params: the hardware parameters to set309 * @dai: the SOC DAI (ignored)310 *311 * This function programs the hardware with the values provided.312 * Specifically, the sample rate and the data format.313 *314 * The .ops functions are used to provide board-specific data, like input315 * frequencies, to this driver.  This function takes that information,316 * combines it with the hardware parameters provided, and programs the317 * hardware accordingly.318 */319static int cs4270_hw_params(struct snd_pcm_substream *substream,320			    struct snd_pcm_hw_params *params,321			    struct snd_soc_dai *dai)322{323	struct snd_soc_component *component = dai->component;324	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);325	int ret;326	unsigned int i;327	unsigned int rate;328	unsigned int ratio;329	int reg;330 331	/* Figure out which MCLK/LRCK ratio to use */332 333	rate = params_rate(params);	/* Sampling rate, in Hz */334	ratio = cs4270->mclk / rate;	/* MCLK/LRCK ratio */335 336	for (i = 0; i < NUM_MCLK_RATIOS; i++) {337		if (cs4270_mode_ratios[i].ratio == ratio)338			break;339	}340 341	if (i == NUM_MCLK_RATIOS) {342		/* We did not find a matching ratio */343		dev_err(component->dev, "could not find matching ratio\n");344		return -EINVAL;345	}346 347	/* Set the sample rate */348 349	reg = snd_soc_component_read(component, CS4270_MODE);350	reg &= ~(CS4270_MODE_SPEED_MASK | CS4270_MODE_DIV_MASK);351	reg |= cs4270_mode_ratios[i].mclk;352 353	if (cs4270->slave_mode)354		reg |= CS4270_MODE_SLAVE;355	else356		reg |= cs4270_mode_ratios[i].speed_mode;357 358	ret = snd_soc_component_write(component, CS4270_MODE, reg);359	if (ret < 0) {360		dev_err(component->dev, "i2c write failed\n");361		return ret;362	}363 364	/* Set the DAI format */365 366	reg = snd_soc_component_read(component, CS4270_FORMAT);367	reg &= ~(CS4270_FORMAT_DAC_MASK | CS4270_FORMAT_ADC_MASK);368 369	switch (cs4270->mode) {370	case SND_SOC_DAIFMT_I2S:371		reg |= CS4270_FORMAT_DAC_I2S | CS4270_FORMAT_ADC_I2S;372		break;373	case SND_SOC_DAIFMT_LEFT_J:374		reg |= CS4270_FORMAT_DAC_LJ | CS4270_FORMAT_ADC_LJ;375		break;376	default:377		dev_err(component->dev, "unknown dai format\n");378		return -EINVAL;379	}380 381	ret = snd_soc_component_write(component, CS4270_FORMAT, reg);382	if (ret < 0) {383		dev_err(component->dev, "i2c write failed\n");384		return ret;385	}386 387	return ret;388}389 390/**391 * cs4270_dai_mute - enable/disable the CS4270 external mute392 * @dai: the SOC DAI393 * @mute: 0 = disable mute, 1 = enable mute394 * @direction: (ignored)395 *396 * This function toggles the mute bits in the MUTE register.  The CS4270's397 * mute capability is intended for external muting circuitry, so if the398 * board does not have the MUTEA or MUTEB pins connected to such circuitry,399 * then this function will do nothing.400 */401static int cs4270_dai_mute(struct snd_soc_dai *dai, int mute, int direction)402{403	struct snd_soc_component *component = dai->component;404	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);405	int reg6;406 407	reg6 = snd_soc_component_read(component, CS4270_MUTE);408 409	if (mute)410		reg6 |= CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B;411	else {412		reg6 &= ~(CS4270_MUTE_DAC_A | CS4270_MUTE_DAC_B);413		reg6 |= cs4270->manual_mute;414	}415 416	return snd_soc_component_write(component, CS4270_MUTE, reg6);417}418 419/**420 * cs4270_soc_put_mute - put callback for the 'Master Playback switch'421 * 			 alsa control.422 * @kcontrol: mixer control423 * @ucontrol: control element information424 *425 * This function basically passes the arguments on to the generic426 * snd_soc_put_volsw() function and saves the mute information in427 * our private data structure. This is because we want to prevent428 * cs4270_dai_mute() neglecting the user's decision to manually429 * mute the codec's output.430 *431 * Returns 0 for success.432 */433static int cs4270_soc_put_mute(struct snd_kcontrol *kcontrol,434				struct snd_ctl_elem_value *ucontrol)435{436	struct snd_soc_component *component = snd_soc_kcontrol_component(kcontrol);437	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);438	int left = !ucontrol->value.integer.value[0];439	int right = !ucontrol->value.integer.value[1];440 441	cs4270->manual_mute = (left ? CS4270_MUTE_DAC_A : 0) |442			      (right ? CS4270_MUTE_DAC_B : 0);443 444	return snd_soc_put_volsw(kcontrol, ucontrol);445}446 447/* A list of non-DAPM controls that the CS4270 supports */448static const struct snd_kcontrol_new cs4270_snd_controls[] = {449	SOC_DOUBLE_R("Master Playback Volume",450		CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1),451	SOC_SINGLE("Digital Sidetone Switch", CS4270_FORMAT, 5, 1, 0),452	SOC_SINGLE("Soft Ramp Switch", CS4270_TRANS, 6, 1, 0),453	SOC_SINGLE("Zero Cross Switch", CS4270_TRANS, 5, 1, 0),454	SOC_SINGLE("De-emphasis filter", CS4270_TRANS, 0, 1, 0),455	SOC_SINGLE("Popguard Switch", CS4270_MODE, 0, 1, 1),456	SOC_SINGLE("Auto-Mute Switch", CS4270_MUTE, 5, 1, 0),457	SOC_DOUBLE("Master Capture Switch", CS4270_MUTE, 3, 4, 1, 1),458	SOC_DOUBLE_EXT("Master Playback Switch", CS4270_MUTE, 0, 1, 1, 1,459		snd_soc_get_volsw, cs4270_soc_put_mute),460};461 462static const struct snd_soc_dai_ops cs4270_dai_ops = {463	.hw_params	= cs4270_hw_params,464	.set_sysclk	= cs4270_set_dai_sysclk,465	.set_fmt	= cs4270_set_dai_fmt,466	.mute_stream	= cs4270_dai_mute,467	.no_capture_mute = 1,468};469 470static struct snd_soc_dai_driver cs4270_dai = {471	.name = "cs4270-hifi",472	.playback = {473		.stream_name = "Playback",474		.channels_min = 2,475		.channels_max = 2,476		.rates = SNDRV_PCM_RATE_CONTINUOUS,477		.rate_min = 4000,478		.rate_max = 216000,479		.formats = CS4270_FORMATS,480	},481	.capture = {482		.stream_name = "Capture",483		.channels_min = 2,484		.channels_max = 2,485		.rates = SNDRV_PCM_RATE_CONTINUOUS,486		.rate_min = 4000,487		.rate_max = 216000,488		.formats = CS4270_FORMATS,489	},490	.ops = &cs4270_dai_ops,491};492 493/**494 * cs4270_probe - ASoC probe function495 * @component: ASoC component496 *497 * This function is called when ASoC has all the pieces it needs to498 * instantiate a sound driver.499 */500static int cs4270_probe(struct snd_soc_component *component)501{502	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);503	int ret;504 505	/* Disable auto-mute.  This feature appears to be buggy.  In some506	 * situations, auto-mute will not deactivate when it should, so we want507	 * this feature disabled by default.  An application (e.g. alsactl) can508	 * re-enabled it by using the controls.509	 */510	ret = snd_soc_component_update_bits(component, CS4270_MUTE, CS4270_MUTE_AUTO, 0);511	if (ret < 0) {512		dev_err(component->dev, "i2c write failed\n");513		return ret;514	}515 516	/* Disable automatic volume control.  The hardware enables, and it517	 * causes volume change commands to be delayed, sometimes until after518	 * playback has started.  An application (e.g. alsactl) can519	 * re-enabled it by using the controls.520	 */521	ret = snd_soc_component_update_bits(component, CS4270_TRANS,522		CS4270_TRANS_SOFT | CS4270_TRANS_ZERO, 0);523	if (ret < 0) {524		dev_err(component->dev, "i2c write failed\n");525		return ret;526	}527 528	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),529				    cs4270->supplies);530 531	return ret;532}533 534/**535 * cs4270_remove - ASoC remove function536 * @component: ASoC component537 *538 * This function is the counterpart to cs4270_probe().539 */540static void cs4270_remove(struct snd_soc_component *component)541{542	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);543 544	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies), cs4270->supplies);545};546 547#ifdef CONFIG_PM548 549/* This suspend/resume implementation can handle both - a simple standby550 * where the codec remains powered, and a full suspend, where the voltage551 * domain the codec is connected to is teared down and/or any other hardware552 * reset condition is asserted.553 *554 * The codec's own power saving features are enabled in the suspend callback,555 * and all registers are written back to the hardware when resuming.556 */557 558static int cs4270_soc_suspend(struct snd_soc_component *component)559{560	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);561	int reg, ret;562 563	reg = snd_soc_component_read(component, CS4270_PWRCTL) | CS4270_PWRCTL_PDN_ALL;564	if (reg < 0)565		return reg;566 567	ret = snd_soc_component_write(component, CS4270_PWRCTL, reg);568	if (ret < 0)569		return ret;570 571	regulator_bulk_disable(ARRAY_SIZE(cs4270->supplies),572			       cs4270->supplies);573 574	return 0;575}576 577static int cs4270_soc_resume(struct snd_soc_component *component)578{579	struct cs4270_private *cs4270 = snd_soc_component_get_drvdata(component);580	int reg, ret;581 582	ret = regulator_bulk_enable(ARRAY_SIZE(cs4270->supplies),583				    cs4270->supplies);584	if (ret != 0)585		return ret;586 587	/* In case the device was put to hard reset during sleep, we need to588	 * wait 500ns here before any I2C communication. */589	ndelay(500);590 591	/* first restore the entire register cache ... */592	regcache_sync(cs4270->regmap);593 594	/* ... then disable the power-down bits */595	reg = snd_soc_component_read(component, CS4270_PWRCTL);596	reg &= ~CS4270_PWRCTL_PDN_ALL;597 598	return snd_soc_component_write(component, CS4270_PWRCTL, reg);599}600#else601#define cs4270_soc_suspend	NULL602#define cs4270_soc_resume	NULL603#endif /* CONFIG_PM */604 605/*606 * ASoC codec driver structure607 */608static const struct snd_soc_component_driver soc_component_device_cs4270 = {609	.probe			= cs4270_probe,610	.remove			= cs4270_remove,611	.suspend		= cs4270_soc_suspend,612	.resume			= cs4270_soc_resume,613	.controls		= cs4270_snd_controls,614	.num_controls		= ARRAY_SIZE(cs4270_snd_controls),615	.dapm_widgets		= cs4270_dapm_widgets,616	.num_dapm_widgets	= ARRAY_SIZE(cs4270_dapm_widgets),617	.dapm_routes		= cs4270_dapm_routes,618	.num_dapm_routes	= ARRAY_SIZE(cs4270_dapm_routes),619	.idle_bias_on		= 1,620	.use_pmdown_time	= 1,621	.endianness		= 1,622};623 624/*625 * cs4270_of_match - the device tree bindings626 */627static const struct of_device_id cs4270_of_match[] = {628	{ .compatible = "cirrus,cs4270", },629	{ }630};631MODULE_DEVICE_TABLE(of, cs4270_of_match);632 633static const struct regmap_config cs4270_regmap = {634	.reg_bits =		8,635	.val_bits =		8,636	.max_register =		CS4270_LASTREG,637	.reg_defaults =		cs4270_reg_defaults,638	.num_reg_defaults =	ARRAY_SIZE(cs4270_reg_defaults),639	.cache_type =		REGCACHE_MAPLE,640	.write_flag_mask =	CS4270_I2C_INCR,641 642	.readable_reg =		cs4270_reg_is_readable,643	.volatile_reg =		cs4270_reg_is_volatile,644};645 646/**647 * cs4270_i2c_remove - deinitialize the I2C interface of the CS4270648 * @i2c_client: the I2C client object649 *650 * This function puts the chip into low power mode when the i2c device651 * is removed.652 */653static void cs4270_i2c_remove(struct i2c_client *i2c_client)654{655	struct cs4270_private *cs4270 = i2c_get_clientdata(i2c_client);656 657	gpiod_set_value_cansleep(cs4270->reset_gpio, 0);658}659 660/**661 * cs4270_i2c_probe - initialize the I2C interface of the CS4270662 * @i2c_client: the I2C client object663 *664 * This function is called whenever the I2C subsystem finds a device that665 * matches the device ID given via a prior call to i2c_add_driver().666 */667static int cs4270_i2c_probe(struct i2c_client *i2c_client)668{669	struct cs4270_private *cs4270;670	unsigned int val;671	int ret, i;672 673	cs4270 = devm_kzalloc(&i2c_client->dev, sizeof(struct cs4270_private),674			      GFP_KERNEL);675	if (!cs4270)676		return -ENOMEM;677 678	/* get the power supply regulators */679	for (i = 0; i < ARRAY_SIZE(supply_names); i++)680		cs4270->supplies[i].supply = supply_names[i];681 682	ret = devm_regulator_bulk_get(&i2c_client->dev,683				      ARRAY_SIZE(cs4270->supplies),684				      cs4270->supplies);685	if (ret < 0)686		return ret;687 688	/* reset the device */689	cs4270->reset_gpio = devm_gpiod_get_optional(&i2c_client->dev, "reset",690						     GPIOD_OUT_LOW);691	if (IS_ERR(cs4270->reset_gpio)) {692		dev_dbg(&i2c_client->dev, "Error getting CS4270 reset GPIO\n");693		return PTR_ERR(cs4270->reset_gpio);694	}695 696	if (cs4270->reset_gpio) {697		dev_dbg(&i2c_client->dev, "Found reset GPIO\n");698		gpiod_set_value_cansleep(cs4270->reset_gpio, 1);699	}700 701	/* Sleep 500ns before i2c communications */702	ndelay(500);703 704	cs4270->regmap = devm_regmap_init_i2c(i2c_client, &cs4270_regmap);705	if (IS_ERR(cs4270->regmap))706		return PTR_ERR(cs4270->regmap);707 708	/* Verify that we have a CS4270 */709	ret = regmap_read(cs4270->regmap, CS4270_CHIPID, &val);710	if (ret < 0) {711		dev_err(&i2c_client->dev, "failed to read i2c at addr %X\n",712		       i2c_client->addr);713		return ret;714	}715	/* The top four bits of the chip ID should be 1100. */716	if ((val & 0xF0) != 0xC0) {717		dev_err(&i2c_client->dev, "device at addr %X is not a CS4270\n",718		       i2c_client->addr);719		return -ENODEV;720	}721 722	dev_info(&i2c_client->dev, "found device at i2c address %X\n",723		i2c_client->addr);724	dev_info(&i2c_client->dev, "hardware revision %X\n", val & 0xF);725 726	i2c_set_clientdata(i2c_client, cs4270);727 728	ret = devm_snd_soc_register_component(&i2c_client->dev,729			&soc_component_device_cs4270, &cs4270_dai, 1);730	return ret;731}732 733/*734 * cs4270_id - I2C device IDs supported by this driver735 */736static const struct i2c_device_id cs4270_id[] = {737	{"cs4270"},738	{}739};740MODULE_DEVICE_TABLE(i2c, cs4270_id);741 742/*743 * cs4270_i2c_driver - I2C device identification744 *745 * This structure tells the I2C subsystem how to identify and support a746 * given I2C device type.747 */748static struct i2c_driver cs4270_i2c_driver = {749	.driver = {750		.name = "cs4270",751		.of_match_table = cs4270_of_match,752	},753	.id_table = cs4270_id,754	.probe = cs4270_i2c_probe,755	.remove = cs4270_i2c_remove,756};757 758module_i2c_driver(cs4270_i2c_driver);759 760MODULE_AUTHOR("Timur Tabi <timur@freescale.com>");761MODULE_DESCRIPTION("Cirrus Logic CS4270 ALSA SoC Codec Driver");762MODULE_LICENSE("GPL");763