drivers/regulator/fan53555.c - third_party/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 //
 // FAN53555 Fairchild Digitally Programmable TinyBuck Regulator Driver.
 //
 // Supported Part Numbers:
 // FAN53555UC00X/01X/03X/04X/05X
 //
 // Copyright (c) 2012 Marvell Technology Ltd.
 // Yunfan Zhang <yfzhang@marvell.com>

 #include <linux/bits.h>
 #include <linux/err.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/param.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/regulator/driver.h>
 #include <linux/regulator/fan53555.h>
 #include <linux/regulator/machine.h>
 #include <linux/regulator/of_regulator.h>
 #include <linux/slab.h>

 /* Voltage setting */
 #define FAN53555_VSEL0		0x00
 #define FAN53555_VSEL1		0x01
 /* Control register */
 #define FAN53555_CONTROL	0x02
 /* IC Type */
 #define FAN53555_ID1		0x03
 /* IC mask version */
 #define FAN53555_ID2		0x04
 /* Monitor register */
 #define FAN53555_MONITOR	0x05

 /* VSEL bit definitions */
 #define VSEL_BUCK_EN	(1 << 7)
 #define VSEL_MODE		(1 << 6)
 /* Chip ID and Verison */
 #define DIE_ID		0x0F	/* ID1 */
 #define DIE_REV		0x0F	/* ID2 */
 /* Control bit definitions */
 #define CTL_OUTPUT_DISCHG	(1 << 7)
 #define CTL_SLEW_MASK		(0x7 << 4)
 #define CTL_SLEW_SHIFT		4
 #define CTL_RESET			(1 << 2)
 #define CTL_MODE_VSEL0_MODE	BIT(0)
 #define CTL_MODE_VSEL1_MODE	BIT(1)

 #define FAN53555_NVOLTAGES	64	/* Numbers of voltages */
 #define FAN53526_NVOLTAGES	128

 enum fan53555_vendor {
 	FAN53526_VENDOR_FAIRCHILD = 0,
 	FAN53555_VENDOR_FAIRCHILD,
 	FAN53555_VENDOR_SILERGY,
 };

 enum {
 	FAN53526_CHIP_ID_01 = 1,
 };

 enum {
 	FAN53526_CHIP_REV_08 = 8,
 };

 /* IC Type */
 enum {
 	FAN53555_CHIP_ID_00 = 0,
 	FAN53555_CHIP_ID_01,
 	FAN53555_CHIP_ID_02,
 	FAN53555_CHIP_ID_03,
 	FAN53555_CHIP_ID_04,
 	FAN53555_CHIP_ID_05,
 	FAN53555_CHIP_ID_08 = 8,
 };

 /* IC mask revision */
 enum {
 	FAN53555_CHIP_REV_00 = 0x3,
 	FAN53555_CHIP_REV_13 = 0xf,
 };

 enum {
 	SILERGY_SYR82X = 8,
 };

 struct fan53555_device_info {
 	enum fan53555_vendor vendor;
 	struct device *dev;
 	struct regulator_desc desc;
 	struct regulator_init_data *regulator;
 	/* IC Type and Rev */
 	int chip_id;
 	int chip_rev;
 	/* Voltage setting register */
 	unsigned int vol_reg;
 	unsigned int sleep_reg;
 	/* Voltage range and step(linear) */
 	unsigned int vsel_min;
 	unsigned int vsel_step;
 	unsigned int vsel_count;
 	/* Mode */
 	unsigned int mode_reg;
 	unsigned int mode_mask;
 	/* Sleep voltage cache */
 	unsigned int sleep_vol_cache;
 };

 static int fan53555_set_suspend_voltage(struct regulator_dev *rdev, int uV)
 {
 	struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 	int ret;

 	if (di->sleep_vol_cache == uV)
 		return 0;
 	ret = regulator_map_voltage_linear(rdev, uV, uV);
 	if (ret < 0)
 		return ret;
 	ret = regmap_update_bits(rdev->regmap, di->sleep_reg,
 				 di->desc.vsel_mask, ret);
 	if (ret < 0)
 		return ret;
 	/* Cache the sleep voltage setting.
 	 * Might not be the real voltage which is rounded */
 	di->sleep_vol_cache = uV;

 	return 0;
 }

 static int fan53555_set_suspend_enable(struct regulator_dev *rdev)
 {
 	struct fan53555_device_info *di = rdev_get_drvdata(rdev);

 	return regmap_update_bits(rdev->regmap, di->sleep_reg,
 				  VSEL_BUCK_EN, VSEL_BUCK_EN);
 }

 static int fan53555_set_suspend_disable(struct regulator_dev *rdev)
 {
 	struct fan53555_device_info *di = rdev_get_drvdata(rdev);

 	return regmap_update_bits(rdev->regmap, di->sleep_reg,
 				  VSEL_BUCK_EN, 0);
 }

 static int fan53555_set_mode(struct regulator_dev *rdev, unsigned int mode)
 {
 	struct fan53555_device_info *di = rdev_get_drvdata(rdev);

 	switch (mode) {
 	case REGULATOR_MODE_FAST:
 		regmap_update_bits(rdev->regmap, di->mode_reg,
 				   di->mode_mask, di->mode_mask);
 		break;
 	case REGULATOR_MODE_NORMAL:
 		regmap_update_bits(rdev->regmap, di->vol_reg, di->mode_mask, 0);
 		break;
 	default:
 		return -EINVAL;
 	}
 	return 0;
 }

 static unsigned int fan53555_get_mode(struct regulator_dev *rdev)
 {
 	struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 	unsigned int val;
 	int ret = 0;

 	ret = regmap_read(rdev->regmap, di->mode_reg, &val);
 	if (ret < 0)
 		return ret;
 	if (val & di->mode_mask)
 		return REGULATOR_MODE_FAST;
 	else
 		return REGULATOR_MODE_NORMAL;
 }

 static const int slew_rates[] = {
 	64000,
 	32000,
 	16000,
 	 8000,
 	 4000,
 	 2000,
 	 1000,
 	  500,
 };

 static int fan53555_set_ramp(struct regulator_dev *rdev, int ramp)
 {
 	struct fan53555_device_info *di = rdev_get_drvdata(rdev);
 	int regval = -1, i;

 	for (i = 0; i < ARRAY_SIZE(slew_rates); i++) {
 		if (ramp <= slew_rates[i])
 			regval = i;
 		else
 			break;
 	}

 	if (regval < 0) {
 		dev_err(di->dev, "unsupported ramp value %d\n", ramp);
 		return -EINVAL;
 	}

 	return regmap_update_bits(rdev->regmap, FAN53555_CONTROL,
 				  CTL_SLEW_MASK, regval << CTL_SLEW_SHIFT);
 }

 static const struct regulator_ops fan53555_regulator_ops = {
 	.set_voltage_sel = regulator_set_voltage_sel_regmap,
 	.get_voltage_sel = regulator_get_voltage_sel_regmap,
 	.set_voltage_time_sel = regulator_set_voltage_time_sel,
 	.map_voltage = regulator_map_voltage_linear,
 	.list_voltage = regulator_list_voltage_linear,
 	.set_suspend_voltage = fan53555_set_suspend_voltage,
 	.enable = regulator_enable_regmap,
 	.disable = regulator_disable_regmap,
 	.is_enabled = regulator_is_enabled_regmap,
 	.set_mode = fan53555_set_mode,
 	.get_mode = fan53555_get_mode,
 	.set_ramp_delay = fan53555_set_ramp,
 	.set_suspend_enable = fan53555_set_suspend_enable,
 	.set_suspend_disable = fan53555_set_suspend_disable,
 };

 static int fan53526_voltages_setup_fairchild(struct fan53555_device_info *di)
 {
 	/* Init voltage range and step */
 	switch (di->chip_id) {
 	case FAN53526_CHIP_ID_01:
 		switch (di->chip_rev) {
 		case FAN53526_CHIP_REV_08:
 			di->vsel_min = 600000;
 			di->vsel_step = 6250;
 			break;
 		default:
 			dev_err(di->dev,
 				"Chip ID %d with rev %d not supported!\n",
 				di->chip_id, di->chip_rev);
 			return -EINVAL;
 		}
 		break;
 	default:
 		dev_err(di->dev,
 			"Chip ID %d not supported!\n", di->chip_id);
 		return -EINVAL;
 	}

 	di->vsel_count = FAN53526_NVOLTAGES;

 	return 0;
 }

 static int fan53555_voltages_setup_fairchild(struct fan53555_device_info *di)
 {
 	/* Init voltage range and step */
 	switch (di->chip_id) {
 	case FAN53555_CHIP_ID_00:
 		switch (di->chip_rev) {
 		case FAN53555_CHIP_REV_00:
 			di->vsel_min = 600000;
 			di->vsel_step = 10000;
 			break;
 		case FAN53555_CHIP_REV_13:
 			di->vsel_min = 800000;
 			di->vsel_step = 10000;
 			break;
 		default:
 			dev_err(di->dev,
 				"Chip ID %d with rev %d not supported!\n",
 				di->chip_id, di->chip_rev);
 			return -EINVAL;
 		}
 		break;
 	case FAN53555_CHIP_ID_01:
 	case FAN53555_CHIP_ID_03:
 	case FAN53555_CHIP_ID_05:
 	case FAN53555_CHIP_ID_08:
 		di->vsel_min = 600000;
 		di->vsel_step = 10000;
 		break;
 	case FAN53555_CHIP_ID_04:
 		di->vsel_min = 603000;
 		di->vsel_step = 12826;
 		break;
 	default:
 		dev_err(di->dev,
 			"Chip ID %d not supported!\n", di->chip_id);
 		return -EINVAL;
 	}

 	di->vsel_count = FAN53555_NVOLTAGES;

 	return 0;
 }

 static int fan53555_voltages_setup_silergy(struct fan53555_device_info *di)
 {
 	/* Init voltage range and step */
 	switch (di->chip_id) {
 	case SILERGY_SYR82X:
 		di->vsel_min = 712500;
 		di->vsel_step = 12500;
 		break;
 	default:
 		dev_err(di->dev,
 			"Chip ID %d not supported!\n", di->chip_id);
 		return -EINVAL;
 	}

 	di->vsel_count = FAN53555_NVOLTAGES;

 	return 0;
 }

 /* For 00,01,03,05 options:
  * VOUT = 0.60V + NSELx * 10mV, from 0.60 to 1.23V.
  * For 04 option:
  * VOUT = 0.603V + NSELx * 12.826mV, from 0.603 to 1.411V.
  * */
 static int fan53555_device_setup(struct fan53555_device_info *di,
 				struct fan53555_platform_data *pdata)
 {
 	int ret = 0;

 	/* Setup voltage control register */
 	switch (pdata->sleep_vsel_id) {
 	case FAN53555_VSEL_ID_0:
 		di->sleep_reg = FAN53555_VSEL0;
 		di->vol_reg = FAN53555_VSEL1;
 		break;
 	case FAN53555_VSEL_ID_1:
 		di->sleep_reg = FAN53555_VSEL1;
 		di->vol_reg = FAN53555_VSEL0;
 		break;
 	default:
 		dev_err(di->dev, "Invalid VSEL ID!\n");
 		return -EINVAL;
 	}

 	/* Setup mode control register */
 	switch (di->vendor) {
 	case FAN53526_VENDOR_FAIRCHILD:
 		di->mode_reg = FAN53555_CONTROL;

 		switch (pdata->sleep_vsel_id) {
 		case FAN53555_VSEL_ID_0:
 			di->mode_mask = CTL_MODE_VSEL1_MODE;
 			break;
 		case FAN53555_VSEL_ID_1:
 			di->mode_mask = CTL_MODE_VSEL0_MODE;
 			break;
 		}
 		break;
 	case FAN53555_VENDOR_FAIRCHILD:
 	case FAN53555_VENDOR_SILERGY:
 		di->mode_reg = di->vol_reg;
 		di->mode_mask = VSEL_MODE;
 		break;
 	default:
 		dev_err(di->dev, "vendor %d not supported!\n", di->vendor);
 		return -EINVAL;
 	}

 	/* Setup voltage range */
 	switch (di->vendor) {
 	case FAN53526_VENDOR_FAIRCHILD:
 		ret = fan53526_voltages_setup_fairchild(di);
 		break;
 	case FAN53555_VENDOR_FAIRCHILD:
 		ret = fan53555_voltages_setup_fairchild(di);
 		break;
 	case FAN53555_VENDOR_SILERGY:
 		ret = fan53555_voltages_setup_silergy(di);
 		break;
 	default:
 		dev_err(di->dev, "vendor %d not supported!\n", di->vendor);
 		return -EINVAL;
 	}

 	return ret;
 }

 static int fan53555_regulator_register(struct fan53555_device_info *di,
 			struct regulator_config *config)
 {
 	struct regulator_desc *rdesc = &di->desc;
 	struct regulator_dev *rdev;

 	rdesc->name = "fan53555-reg";
 	rdesc->supply_name = "vin";
 	rdesc->ops = &fan53555_regulator_ops;
 	rdesc->type = REGULATOR_VOLTAGE;
 	rdesc->n_voltages = di->vsel_count;
 	rdesc->enable_reg = di->vol_reg;
 	rdesc->enable_mask = VSEL_BUCK_EN;
 	rdesc->min_uV = di->vsel_min;
 	rdesc->uV_step = di->vsel_step;
 	rdesc->vsel_reg = di->vol_reg;
 	rdesc->vsel_mask = di->vsel_count - 1;
 	rdesc->owner = THIS_MODULE;

 	rdev = devm_regulator_register(di->dev, &di->desc, config);
 	return PTR_ERR_OR_ZERO(rdev);
 }

 static const struct regmap_config fan53555_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 8,
 };

 static struct fan53555_platform_data *fan53555_parse_dt(struct device *dev,
 					      struct device_node *np,
 					      const struct regulator_desc *desc)
 {
 	struct fan53555_platform_data *pdata;
 	int ret;
 	u32 tmp;

 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
 	if (!pdata)
 		return NULL;

 	pdata->regulator = of_get_regulator_init_data(dev, np, desc);

 	ret = of_property_read_u32(np, "fcs,suspend-voltage-selector",
 				   &tmp);
 	if (!ret)
 		pdata->sleep_vsel_id = tmp;

 	return pdata;
 }

 static const struct of_device_id fan53555_dt_ids[] = {
 	{
 		.compatible = "fcs,fan53526",
 		.data = (void *)FAN53526_VENDOR_FAIRCHILD,
 	}, {
 		.compatible = "fcs,fan53555",
 		.data = (void *)FAN53555_VENDOR_FAIRCHILD
 	}, {
 		.compatible = "silergy,syr827",
 		.data = (void *)FAN53555_VENDOR_SILERGY,
 	}, {
 		.compatible = "silergy,syr828",
 		.data = (void *)FAN53555_VENDOR_SILERGY,
 	},
 	{ }
 };
 MODULE_DEVICE_TABLE(of, fan53555_dt_ids);

 static int fan53555_regulator_probe(struct i2c_client *client,
 				const struct i2c_device_id *id)
 {
 	struct device_node *np = client->dev.of_node;
 	struct fan53555_device_info *di;
 	struct fan53555_platform_data *pdata;
 	struct regulator_config config = { };
 	struct regmap *regmap;
 	unsigned int val;
 	int ret;

 	di = devm_kzalloc(&client->dev, sizeof(struct fan53555_device_info),
 					GFP_KERNEL);
 	if (!di)
 		return -ENOMEM;

 	pdata = dev_get_platdata(&client->dev);
 	if (!pdata)
 		pdata = fan53555_parse_dt(&client->dev, np, &di->desc);

 	if (!pdata || !pdata->regulator) {
 		dev_err(&client->dev, "Platform data not found!\n");
 		return -ENODEV;
 	}

 	di->regulator = pdata->regulator;
 	if (client->dev.of_node) {
 		di->vendor =
 			(unsigned long)of_device_get_match_data(&client->dev);
 	} else {
 		/* if no ramp constraint set, get the pdata ramp_delay */
 		if (!di->regulator->constraints.ramp_delay) {
 			if (pdata->slew_rate >= ARRAY_SIZE(slew_rates)) {
 				dev_err(&client->dev, "Invalid slew_rate\n");
 				return -EINVAL;
 			}

 			di->regulator->constraints.ramp_delay
 					= slew_rates[pdata->slew_rate];
 		}

 		di->vendor = id->driver_data;
 	}

 	regmap = devm_regmap_init_i2c(client, &fan53555_regmap_config);
 	if (IS_ERR(regmap)) {
 		dev_err(&client->dev, "Failed to allocate regmap!\n");
 		return PTR_ERR(regmap);
 	}
 	di->dev = &client->dev;
 	i2c_set_clientdata(client, di);
 	/* Get chip ID */
 	ret = regmap_read(regmap, FAN53555_ID1, &val);
 	if (ret < 0) {
 		dev_err(&client->dev, "Failed to get chip ID!\n");
 		return ret;
 	}
 	di->chip_id = val & DIE_ID;
 	/* Get chip revision */
 	ret = regmap_read(regmap, FAN53555_ID2, &val);
 	if (ret < 0) {
 		dev_err(&client->dev, "Failed to get chip Rev!\n");
 		return ret;
 	}
 	di->chip_rev = val & DIE_REV;
 	dev_info(&client->dev, "FAN53555 Option[%d] Rev[%d] Detected!\n",
 				di->chip_id, di->chip_rev);
 	/* Device init */
 	ret = fan53555_device_setup(di, pdata);
 	if (ret < 0) {
 		dev_err(&client->dev, "Failed to setup device!\n");
 		return ret;
 	}
 	/* Register regulator */
 	config.dev = di->dev;
 	config.init_data = di->regulator;
 	config.regmap = regmap;
 	config.driver_data = di;
 	config.of_node = np;

 	ret = fan53555_regulator_register(di, &config);
 	if (ret < 0)
 		dev_err(&client->dev, "Failed to register regulator!\n");
 	return ret;

 }

 static const struct i2c_device_id fan53555_id[] = {
 	{
 		.name = "fan53526",
 		.driver_data = FAN53526_VENDOR_FAIRCHILD
 	}, {
 		.name = "fan53555",
 		.driver_data = FAN53555_VENDOR_FAIRCHILD
 	}, {
 		.name = "syr827",
 		.driver_data = FAN53555_VENDOR_SILERGY
 	}, {
 		.name = "syr828",
 		.driver_data = FAN53555_VENDOR_SILERGY
 	},
 	{ },
 };
 MODULE_DEVICE_TABLE(i2c, fan53555_id);

 static struct i2c_driver fan53555_regulator_driver = {
 	.driver = {
 		.name = "fan53555-regulator",
 		.of_match_table = of_match_ptr(fan53555_dt_ids),
 	},
 	.probe = fan53555_regulator_probe,
 	.id_table = fan53555_id,
 };

 module_i2c_driver(fan53555_regulator_driver);

 MODULE_AUTHOR("Yunfan Zhang <yfzhang@marvell.com>");
 MODULE_DESCRIPTION("FAN53555 regulator driver");
 MODULE_LICENSE("GPL v2");
	// SPDX-License-Identifier: GPL-2.0
	//
	// FAN53555 Fairchild Digitally Programmable TinyBuck Regulator Driver.
	//
	// Supported Part Numbers:
	// FAN53555UC00X/01X/03X/04X/05X
	//
	// Copyright (c) 2012 Marvell Technology Ltd.
	// Yunfan Zhang <yfzhang@marvell.com>

	#include <linux/bits.h>
	#include <linux/err.h>
	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/param.h>
	#include <linux/platform_device.h>
	#include <linux/regmap.h>
	#include <linux/regulator/driver.h>
	#include <linux/regulator/fan53555.h>
	#include <linux/regulator/machine.h>
	#include <linux/regulator/of_regulator.h>
	#include <linux/slab.h>

	/* Voltage setting */
	#define FAN53555_VSEL0 0x00
	#define FAN53555_VSEL1 0x01
	/* Control register */
	#define FAN53555_CONTROL 0x02
	/* IC Type */
	#define FAN53555_ID1 0x03
	/* IC mask version */
	#define FAN53555_ID2 0x04
	/* Monitor register */
	#define FAN53555_MONITOR 0x05

	/* VSEL bit definitions */
	#define VSEL_BUCK_EN (1 << 7)
	#define VSEL_MODE (1 << 6)
	/* Chip ID and Verison */
	#define DIE_ID 0x0F /* ID1 */
	#define DIE_REV 0x0F /* ID2 */
	/* Control bit definitions */
	#define CTL_OUTPUT_DISCHG (1 << 7)
	#define CTL_SLEW_MASK (0x7 << 4)
	#define CTL_SLEW_SHIFT 4
	#define CTL_RESET (1 << 2)
	#define CTL_MODE_VSEL0_MODE BIT(0)
	#define CTL_MODE_VSEL1_MODE BIT(1)

	#define FAN53555_NVOLTAGES 64 /* Numbers of voltages */
	#define FAN53526_NVOLTAGES 128

	enum fan53555_vendor {
	FAN53526_VENDOR_FAIRCHILD = 0,
	FAN53555_VENDOR_FAIRCHILD,
	FAN53555_VENDOR_SILERGY,
	};

	enum {
	FAN53526_CHIP_ID_01 = 1,
	};

	enum {
	FAN53526_CHIP_REV_08 = 8,
	};

	/* IC Type */
	enum {
	FAN53555_CHIP_ID_00 = 0,
	FAN53555_CHIP_ID_01,
	FAN53555_CHIP_ID_02,
	FAN53555_CHIP_ID_03,
	FAN53555_CHIP_ID_04,
	FAN53555_CHIP_ID_05,
	FAN53555_CHIP_ID_08 = 8,
	};

	/* IC mask revision */
	enum {
	FAN53555_CHIP_REV_00 = 0x3,
	FAN53555_CHIP_REV_13 = 0xf,
	};

	enum {
	SILERGY_SYR82X = 8,
	};

	struct fan53555_device_info {
	enum fan53555_vendor vendor;
	struct device *dev;
	struct regulator_desc desc;
	struct regulator_init_data *regulator;
	/* IC Type and Rev */
	int chip_id;
	int chip_rev;
	/* Voltage setting register */
	unsigned int vol_reg;
	unsigned int sleep_reg;
	/* Voltage range and step(linear) */
	unsigned int vsel_min;
	unsigned int vsel_step;
	unsigned int vsel_count;
	/* Mode */
	unsigned int mode_reg;
	unsigned int mode_mask;
	/* Sleep voltage cache */
	unsigned int sleep_vol_cache;
	};

	static int fan53555_set_suspend_voltage(struct regulator_dev *rdev, int uV)
	{
	struct fan53555_device_info *di = rdev_get_drvdata(rdev);
	int ret;

	if (di->sleep_vol_cache == uV)
	return 0;
	ret = regulator_map_voltage_linear(rdev, uV, uV);
	if (ret < 0)
	return ret;
	ret = regmap_update_bits(rdev->regmap, di->sleep_reg,
	di->desc.vsel_mask, ret);
	if (ret < 0)
	return ret;
	/* Cache the sleep voltage setting.
	* Might not be the real voltage which is rounded */
	di->sleep_vol_cache = uV;

	return 0;
	}

	static int fan53555_set_suspend_enable(struct regulator_dev *rdev)
	{
	struct fan53555_device_info *di = rdev_get_drvdata(rdev);

	return regmap_update_bits(rdev->regmap, di->sleep_reg,
	VSEL_BUCK_EN, VSEL_BUCK_EN);
	}

	static int fan53555_set_suspend_disable(struct regulator_dev *rdev)
	{
	struct fan53555_device_info *di = rdev_get_drvdata(rdev);

	return regmap_update_bits(rdev->regmap, di->sleep_reg,
	VSEL_BUCK_EN, 0);
	}

	static int fan53555_set_mode(struct regulator_dev *rdev, unsigned int mode)
	{
	struct fan53555_device_info *di = rdev_get_drvdata(rdev);

	switch (mode) {
	case REGULATOR_MODE_FAST:
	regmap_update_bits(rdev->regmap, di->mode_reg,
	di->mode_mask, di->mode_mask);
	break;
	case REGULATOR_MODE_NORMAL:
	regmap_update_bits(rdev->regmap, di->vol_reg, di->mode_mask, 0);
	break;
	default:
	return -EINVAL;
	}
	return 0;
	}

	static unsigned int fan53555_get_mode(struct regulator_dev *rdev)
	{
	struct fan53555_device_info *di = rdev_get_drvdata(rdev);
	unsigned int val;
	int ret = 0;

	ret = regmap_read(rdev->regmap, di->mode_reg, &val);
	if (ret < 0)
	return ret;
	if (val & di->mode_mask)
	return REGULATOR_MODE_FAST;
	else
	return REGULATOR_MODE_NORMAL;
	}

	static const int slew_rates[] = {
	64000,
	32000,
	16000,
	8000,
	4000,
	2000,
	1000,
	500,
	};

	static int fan53555_set_ramp(struct regulator_dev *rdev, int ramp)
	{
	struct fan53555_device_info *di = rdev_get_drvdata(rdev);
	int regval = -1, i;

	for (i = 0; i < ARRAY_SIZE(slew_rates); i++) {
	if (ramp <= slew_rates[i])
	regval = i;
	else
	break;
	}

	if (regval < 0) {
	dev_err(di->dev, "unsupported ramp value %d\n", ramp);
	return -EINVAL;
	}

	return regmap_update_bits(rdev->regmap, FAN53555_CONTROL,
	CTL_SLEW_MASK, regval << CTL_SLEW_SHIFT);
	}

	static const struct regulator_ops fan53555_regulator_ops = {
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_time_sel = regulator_set_voltage_time_sel,
	.map_voltage = regulator_map_voltage_linear,
	.list_voltage = regulator_list_voltage_linear,
	.set_suspend_voltage = fan53555_set_suspend_voltage,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.set_mode = fan53555_set_mode,
	.get_mode = fan53555_get_mode,
	.set_ramp_delay = fan53555_set_ramp,
	.set_suspend_enable = fan53555_set_suspend_enable,
	.set_suspend_disable = fan53555_set_suspend_disable,
	};

	static int fan53526_voltages_setup_fairchild(struct fan53555_device_info *di)
	{
	/* Init voltage range and step */
	switch (di->chip_id) {
	case FAN53526_CHIP_ID_01:
	switch (di->chip_rev) {
	case FAN53526_CHIP_REV_08:
	di->vsel_min = 600000;
	di->vsel_step = 6250;
	break;
	default:
	dev_err(di->dev,
	"Chip ID %d with rev %d not supported!\n",
	di->chip_id, di->chip_rev);
	return -EINVAL;
	}
	break;
	default:
	dev_err(di->dev,
	"Chip ID %d not supported!\n", di->chip_id);
	return -EINVAL;
	}

	di->vsel_count = FAN53526_NVOLTAGES;

	return 0;
	}

	static int fan53555_voltages_setup_fairchild(struct fan53555_device_info *di)
	{
	/* Init voltage range and step */
	switch (di->chip_id) {
	case FAN53555_CHIP_ID_00:
	switch (di->chip_rev) {
	case FAN53555_CHIP_REV_00:
	di->vsel_min = 600000;
	di->vsel_step = 10000;
	break;
	case FAN53555_CHIP_REV_13:
	di->vsel_min = 800000;
	di->vsel_step = 10000;
	break;
	default:
	dev_err(di->dev,
	"Chip ID %d with rev %d not supported!\n",
	di->chip_id, di->chip_rev);
	return -EINVAL;
	}
	break;
	case FAN53555_CHIP_ID_01:
	case FAN53555_CHIP_ID_03:
	case FAN53555_CHIP_ID_05:
	case FAN53555_CHIP_ID_08:
	di->vsel_min = 600000;
	di->vsel_step = 10000;
	break;
	case FAN53555_CHIP_ID_04:
	di->vsel_min = 603000;
	di->vsel_step = 12826;
	break;
	default:
	dev_err(di->dev,
	"Chip ID %d not supported!\n", di->chip_id);
	return -EINVAL;
	}

	di->vsel_count = FAN53555_NVOLTAGES;

	return 0;
	}

	static int fan53555_voltages_setup_silergy(struct fan53555_device_info *di)
	{
	/* Init voltage range and step */
	switch (di->chip_id) {
	case SILERGY_SYR82X:
	di->vsel_min = 712500;
	di->vsel_step = 12500;
	break;
	default:
	dev_err(di->dev,
	"Chip ID %d not supported!\n", di->chip_id);
	return -EINVAL;
	}

	di->vsel_count = FAN53555_NVOLTAGES;

	return 0;
	}

	/* For 00,01,03,05 options:
	* VOUT = 0.60V + NSELx * 10mV, from 0.60 to 1.23V.
	* For 04 option:
	* VOUT = 0.603V + NSELx * 12.826mV, from 0.603 to 1.411V.
	* */
	static int fan53555_device_setup(struct fan53555_device_info *di,
	struct fan53555_platform_data *pdata)
	{
	int ret = 0;

	/* Setup voltage control register */
	switch (pdata->sleep_vsel_id) {
	case FAN53555_VSEL_ID_0:
	di->sleep_reg = FAN53555_VSEL0;
	di->vol_reg = FAN53555_VSEL1;
	break;
	case FAN53555_VSEL_ID_1:
	di->sleep_reg = FAN53555_VSEL1;
	di->vol_reg = FAN53555_VSEL0;
	break;
	default:
	dev_err(di->dev, "Invalid VSEL ID!\n");
	return -EINVAL;
	}

	/* Setup mode control register */
	switch (di->vendor) {
	case FAN53526_VENDOR_FAIRCHILD:
	di->mode_reg = FAN53555_CONTROL;

	switch (pdata->sleep_vsel_id) {
	case FAN53555_VSEL_ID_0:
	di->mode_mask = CTL_MODE_VSEL1_MODE;
	break;
	case FAN53555_VSEL_ID_1:
	di->mode_mask = CTL_MODE_VSEL0_MODE;
	break;
	}
	break;
	case FAN53555_VENDOR_FAIRCHILD:
	case FAN53555_VENDOR_SILERGY:
	di->mode_reg = di->vol_reg;
	di->mode_mask = VSEL_MODE;
	break;
	default:
	dev_err(di->dev, "vendor %d not supported!\n", di->vendor);
	return -EINVAL;
	}

	/* Setup voltage range */
	switch (di->vendor) {
	case FAN53526_VENDOR_FAIRCHILD:
	ret = fan53526_voltages_setup_fairchild(di);
	break;
	case FAN53555_VENDOR_FAIRCHILD:
	ret = fan53555_voltages_setup_fairchild(di);
	break;
	case FAN53555_VENDOR_SILERGY:
	ret = fan53555_voltages_setup_silergy(di);
	break;
	default:
	dev_err(di->dev, "vendor %d not supported!\n", di->vendor);
	return -EINVAL;
	}

	return ret;
	}

	static int fan53555_regulator_register(struct fan53555_device_info *di,
	struct regulator_config *config)
	{
	struct regulator_desc *rdesc = &di->desc;
	struct regulator_dev *rdev;

	rdesc->name = "fan53555-reg";
	rdesc->supply_name = "vin";
	rdesc->ops = &fan53555_regulator_ops;
	rdesc->type = REGULATOR_VOLTAGE;
	rdesc->n_voltages = di->vsel_count;
	rdesc->enable_reg = di->vol_reg;
	rdesc->enable_mask = VSEL_BUCK_EN;
	rdesc->min_uV = di->vsel_min;
	rdesc->uV_step = di->vsel_step;
	rdesc->vsel_reg = di->vol_reg;
	rdesc->vsel_mask = di->vsel_count - 1;
	rdesc->owner = THIS_MODULE;

	rdev = devm_regulator_register(di->dev, &di->desc, config);
	return PTR_ERR_OR_ZERO(rdev);
	}

	static const struct regmap_config fan53555_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	};

	static struct fan53555_platform_data fan53555_parse_dt(struct device dev,
	struct device_node *np,
	const struct regulator_desc *desc)
	{
	struct fan53555_platform_data *pdata;
	int ret;
	u32 tmp;

	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
	if (!pdata)
	return NULL;

	pdata->regulator = of_get_regulator_init_data(dev, np, desc);

	ret = of_property_read_u32(np, "fcs,suspend-voltage-selector",
	&tmp);
	if (!ret)
	pdata->sleep_vsel_id = tmp;

	return pdata;
	}

	static const struct of_device_id fan53555_dt_ids[] = {
	{
	.compatible = "fcs,fan53526",
	.data = (void *)FAN53526_VENDOR_FAIRCHILD,
	}, {
	.compatible = "fcs,fan53555",
	.data = (void *)FAN53555_VENDOR_FAIRCHILD
	}, {
	.compatible = "silergy,syr827",
	.data = (void *)FAN53555_VENDOR_SILERGY,
	}, {
	.compatible = "silergy,syr828",
	.data = (void *)FAN53555_VENDOR_SILERGY,
	},
	{ }
	};
	MODULE_DEVICE_TABLE(of, fan53555_dt_ids);

	static int fan53555_regulator_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct device_node *np = client->dev.of_node;
	struct fan53555_device_info *di;
	struct fan53555_platform_data *pdata;
	struct regulator_config config = { };
	struct regmap *regmap;
	unsigned int val;
	int ret;

	di = devm_kzalloc(&client->dev, sizeof(struct fan53555_device_info),
	GFP_KERNEL);
	if (!di)
	return -ENOMEM;

	pdata = dev_get_platdata(&client->dev);
	if (!pdata)
	pdata = fan53555_parse_dt(&client->dev, np, &di->desc);

	if (!pdata \|\| !pdata->regulator) {
	dev_err(&client->dev, "Platform data not found!\n");
	return -ENODEV;
	}

	di->regulator = pdata->regulator;
	if (client->dev.of_node) {
	di->vendor =
	(unsigned long)of_device_get_match_data(&client->dev);
	} else {
	/* if no ramp constraint set, get the pdata ramp_delay */
	if (!di->regulator->constraints.ramp_delay) {
	if (pdata->slew_rate >= ARRAY_SIZE(slew_rates)) {
	dev_err(&client->dev, "Invalid slew_rate\n");
	return -EINVAL;
	}

	di->regulator->constraints.ramp_delay
	= slew_rates[pdata->slew_rate];
	}

	di->vendor = id->driver_data;
	}

	regmap = devm_regmap_init_i2c(client, &fan53555_regmap_config);
	if (IS_ERR(regmap)) {
	dev_err(&client->dev, "Failed to allocate regmap!\n");
	return PTR_ERR(regmap);
	}
	di->dev = &client->dev;
	i2c_set_clientdata(client, di);
	/* Get chip ID */
	ret = regmap_read(regmap, FAN53555_ID1, &val);
	if (ret < 0) {
	dev_err(&client->dev, "Failed to get chip ID!\n");
	return ret;
	}
	di->chip_id = val & DIE_ID;
	/* Get chip revision */
	ret = regmap_read(regmap, FAN53555_ID2, &val);
	if (ret < 0) {
	dev_err(&client->dev, "Failed to get chip Rev!\n");
	return ret;
	}
	di->chip_rev = val & DIE_REV;
	dev_info(&client->dev, "FAN53555 Option[%d] Rev[%d] Detected!\n",
	di->chip_id, di->chip_rev);
	/* Device init */
	ret = fan53555_device_setup(di, pdata);
	if (ret < 0) {
	dev_err(&client->dev, "Failed to setup device!\n");
	return ret;
	}
	/* Register regulator */
	config.dev = di->dev;
	config.init_data = di->regulator;
	config.regmap = regmap;
	config.driver_data = di;
	config.of_node = np;

	ret = fan53555_regulator_register(di, &config);
	if (ret < 0)
	dev_err(&client->dev, "Failed to register regulator!\n");
	return ret;

	}

	static const struct i2c_device_id fan53555_id[] = {
	{
	.name = "fan53526",
	.driver_data = FAN53526_VENDOR_FAIRCHILD
	}, {
	.name = "fan53555",
	.driver_data = FAN53555_VENDOR_FAIRCHILD
	}, {
	.name = "syr827",
	.driver_data = FAN53555_VENDOR_SILERGY
	}, {
	.name = "syr828",
	.driver_data = FAN53555_VENDOR_SILERGY
	},
	{ },
	};
	MODULE_DEVICE_TABLE(i2c, fan53555_id);

	static struct i2c_driver fan53555_regulator_driver = {
	.driver = {
	.name = "fan53555-regulator",
	.of_match_table = of_match_ptr(fan53555_dt_ids),
	},
	.probe = fan53555_regulator_probe,
	.id_table = fan53555_id,
	};

	module_i2c_driver(fan53555_regulator_driver);

	MODULE_AUTHOR("Yunfan Zhang <yfzhang@marvell.com>");
	MODULE_DESCRIPTION("FAN53555 regulator driver");
	MODULE_LICENSE("GPL v2");