linux/drivers/regulator/da9121-regulator.c

// SPDX-License-Identifier: GPL-2.0-only
//
// DA9121 Single-channel dual-phase 10A buck converter
//
// Copyright (C) 2020 Axis Communications AB
//
// DA9130 Single-channel dual-phase 10A buck converter (Automotive)
// DA9217 Single-channel dual-phase  6A buck converter
// DA9122 Dual-channel single-phase  5A buck converter
// DA9131 Dual-channel single-phase  5A buck converter (Automotive)
// DA9220 Dual-channel single-phase  3A buck converter
// DA9132 Dual-channel single-phase  3A buck converter (Automotive)
//
// Copyright (C) 2020 Dialog Semiconductor

#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/driver.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/regulator/da9121.h>

#include "da9121-regulator.h"

/* Chip data */
struct da9121 {
	struct device *dev;
	struct da9121_pdata *pdata;
	struct regmap *regmap;
	struct regulator_dev *rdev[DA9121_IDX_MAX];
	int variant_id;
};

/* Define ranges for different variants, enabling translation to/from
 * registers. Maximums give scope to allow for transients.
 */
struct da9121_range {
	int val_min;
	int val_max;
	int val_stp;
	int reg_min;
	int reg_max;
};

struct da9121_range da9121_10A_2phase_current = {
	.val_min =  7000000,
	.val_max = 20000000,
	.val_stp =  1000000,
	.reg_min = 1,
	.reg_max = 14,
};

struct da9121_range da9121_6A_2phase_current = {
	.val_min =  7000000,
	.val_max = 12000000,
	.val_stp =  1000000,
	.reg_min = 1,
	.reg_max = 6,
};

struct da9121_range da9121_5A_1phase_current = {
	.val_min =  3500000,
	.val_max = 10000000,
	.val_stp =   500000,
	.reg_min = 1,
	.reg_max = 14,
};

struct da9121_range da9121_3A_1phase_current = {
	.val_min = 3500000,
	.val_max = 6000000,
	.val_stp =  500000,
	.reg_min = 1,
	.reg_max = 6,
};

struct da9121_variant_info {
	int num_bucks;
	int num_phases;
	struct da9121_range *current_range;
};

static const struct da9121_variant_info variant_parameters[] = {
	{ 1, 2, &da9121_10A_2phase_current },	//DA9121_TYPE_DA9121_DA9130
	{ 2, 1, &da9121_3A_1phase_current  },	//DA9121_TYPE_DA9220_DA9132
	{ 2, 1, &da9121_5A_1phase_current  },	//DA9121_TYPE_DA9122_DA9131
	{ 1, 2, &da9121_6A_2phase_current  },	//DA9121_TYPE_DA9217
};

struct da9121_field {
	unsigned int reg;
	unsigned int msk;
};

static const struct da9121_field da9121_current_field[2] = {
	{ DA9121_REG_BUCK_BUCK1_2, DA9121_MASK_BUCK_BUCKx_2_CHx_ILIM },
	{ DA9xxx_REG_BUCK_BUCK2_2, DA9121_MASK_BUCK_BUCKx_2_CHx_ILIM },
};

static const struct da9121_field da9121_mode_field[2] = {
	{ DA9121_REG_BUCK_BUCK1_4, DA9121_MASK_BUCK_BUCKx_4_CHx_A_MODE },
	{ DA9xxx_REG_BUCK_BUCK2_4, DA9121_MASK_BUCK_BUCKx_4_CHx_A_MODE },
};

static int da9121_get_current_limit(struct regulator_dev *rdev)
{
	struct da9121 *chip = rdev_get_drvdata(rdev);
	int id = rdev_get_id(rdev);
	struct da9121_range *range =
		variant_parameters[chip->variant_id].current_range;
	unsigned int val = 0;
	int ret = 0;

	ret = regmap_read(chip->regmap, da9121_current_field[id].reg, &val);
	if (ret < 0) {
		dev_err(chip->dev, "Cannot read BUCK register: %d\n", ret);
		goto error;
	}

	if (val < range->reg_min) {
		ret = -EACCES;
		goto error;
	}

	if (val > range->reg_max) {
		ret = -EINVAL;
		goto error;
	}

	return range->val_min + (range->val_stp * (val - range->reg_min));
error:
	return ret;
}

static int da9121_ceiling_selector(struct regulator_dev *rdev,
		int min, int max,
		unsigned int *selector)
{
	struct da9121 *chip = rdev_get_drvdata(rdev);
	struct da9121_range *range =
		variant_parameters[chip->variant_id].current_range;
	unsigned int level;
	unsigned int i = 0;
	unsigned int sel = 0;
	int ret = 0;

	if (range->val_min > max || range->val_max < min) {
		dev_err(chip->dev,
			"Requested current out of regulator capability\n");
		ret = -EINVAL;
		goto error;
	}

	level = range->val_max;
	for (i = range->reg_max; i >= range->reg_min; i--) {
		if (level <= max) {
			sel = i;
			break;
		}
		level -= range->val_stp;
	}

	if (level < min) {
		dev_err(chip->dev,
			"Best match falls below minimum requested current\n");
		ret = -EINVAL;
		goto error;
	}

	*selector = sel;
error:
	return ret;
}

static int da9121_set_current_limit(struct regulator_dev *rdev,
				int min_ua, int max_ua)
{
	struct da9121 *chip = rdev_get_drvdata(rdev);
	int id = rdev_get_id(rdev);
	struct da9121_range *range =
		variant_parameters[chip->variant_id].current_range;
	unsigned int sel = 0;
	int ret = 0;

	if (min_ua < range->val_min ||
	    max_ua > range->val_max) {
		ret = -EINVAL;
		goto error;
	}

	ret = da9121_ceiling_selector(rdev, min_ua, max_ua, &sel);
	if (ret < 0)
		goto error;

	ret = regmap_update_bits(chip->regmap,
				da9121_current_field[id].reg,
				da9121_current_field[id].msk,
				(unsigned int)sel);
	if (ret < 0)
		dev_err(chip->dev, "Cannot update BUCK current limit, err: %d\n", ret);

error:
	return ret;
}

static unsigned int da9121_map_mode(unsigned int mode)
{
	switch (mode) {
	case DA9121_BUCK_MODE_FORCE_PWM:
		return REGULATOR_MODE_FAST;
	case DA9121_BUCK_MODE_FORCE_PWM_SHEDDING:
		return REGULATOR_MODE_NORMAL;
	case DA9121_BUCK_MODE_AUTO:
		return REGULATOR_MODE_IDLE;
	case DA9121_BUCK_MODE_FORCE_PFM:
		return REGULATOR_MODE_STANDBY;
	default:
		return -EINVAL;
	}
}

static int da9121_buck_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
	struct da9121 *chip = rdev_get_drvdata(rdev);
	int id = rdev_get_id(rdev);
	unsigned int val;

	switch (mode) {
	case REGULATOR_MODE_FAST:
		val = DA9121_BUCK_MODE_FORCE_PWM;
		break;
	case REGULATOR_MODE_NORMAL:
		val = DA9121_BUCK_MODE_FORCE_PWM_SHEDDING;
		break;
	case REGULATOR_MODE_IDLE:
		val = DA9121_BUCK_MODE_AUTO;
		break;
	case REGULATOR_MODE_STANDBY:
		val = DA9121_BUCK_MODE_FORCE_PFM;
		break;
	default:
		return -EINVAL;
	}

	return regmap_update_bits(chip->regmap,
				  da9121_mode_field[id].reg,
				  da9121_mode_field[id].msk,
				  val);
}

static unsigned int da9121_buck_get_mode(struct regulator_dev *rdev)
{
	struct da9121 *chip = rdev_get_drvdata(rdev);
	int id = rdev_get_id(rdev);
	unsigned int val;
	int ret = 0;

	ret = regmap_read(chip->regmap, da9121_mode_field[id].reg, &val);
	if (ret < 0) {
		dev_err(chip->dev, "Cannot read BUCK register: %d\n", ret);
		return -EINVAL;
	}

	return da9121_map_mode(val & da9121_mode_field[id].msk);
}

static const struct regulator_ops da9121_buck_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.list_voltage = regulator_list_voltage_linear,
	.get_current_limit = da9121_get_current_limit,
	.set_current_limit = da9121_set_current_limit,
	.set_mode = da9121_buck_set_mode,
	.get_mode = da9121_buck_get_mode,
};

static struct of_regulator_match da9121_matches[] = {
	[DA9121_IDX_BUCK1] = { .name = "buck1" },
	[DA9121_IDX_BUCK2] = { .name = "buck2" },
};

static int da9121_of_parse_cb(struct device_node *np,
				const struct regulator_desc *desc,
				struct regulator_config *config)
{
	struct da9121 *chip = config->driver_data;
	struct da9121_pdata *pdata;
	struct gpio_desc *ena_gpiod;

	if (chip->pdata == NULL) {
		pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL);
		if (!pdata)
			return -ENOMEM;
	} else {
		pdata = chip->pdata;
	}

	pdata->num_buck++;

	if (pdata->num_buck > variant_parameters[chip->variant_id].num_bucks) {
		dev_err(chip->dev, "Error: excessive regulators for device\n");
		return -ENODEV;
	}

	ena_gpiod = fwnode_gpiod_get_index(of_fwnode_handle(np), "enable", 0,
						GPIOD_OUT_HIGH |
						GPIOD_FLAGS_BIT_NONEXCLUSIVE,
						"da9121-enable");
	if (!IS_ERR(ena_gpiod))
		config->ena_gpiod = ena_gpiod;

	if (variant_parameters[chip->variant_id].num_bucks == 2) {
		uint32_t ripple_cancel;
		uint32_t ripple_reg;
		int ret;

		if (of_property_read_u32(da9121_matches[pdata->num_buck].of_node,
				"dlg,ripple-cancel", &ripple_cancel)) {
			if (pdata->num_buck > 1)
				ripple_reg = DA9xxx_REG_BUCK_BUCK2_7;
			else
				ripple_reg = DA9121_REG_BUCK_BUCK1_7;

			ret = regmap_update_bits(chip->regmap, ripple_reg,
				DA9xxx_MASK_BUCK_BUCKx_7_CHx_RIPPLE_CANCEL,
				ripple_cancel);
			if (ret < 0)
				dev_err(chip->dev, "Cannot set ripple mode, err: %d\n", ret);
		}
	}

	return 0;
}

#define DA9121_MIN_MV		300
#define DA9121_MAX_MV		1900
#define DA9121_STEP_MV		10
#define DA9121_MIN_SEL		(DA9121_MIN_MV / DA9121_STEP_MV)
#define DA9121_N_VOLTAGES	(((DA9121_MAX_MV - DA9121_MIN_MV) / DA9121_STEP_MV) \
				 + 1 + DA9121_MIN_SEL)

static const struct regulator_desc da9121_reg = {
	.id = DA9121_IDX_BUCK1,
	.name = "da9121",
	.of_match = "buck1",
	.of_parse_cb = da9121_of_parse_cb,
	.owner = THIS_MODULE,
	.regulators_node = of_match_ptr("regulators"),
	.of_map_mode = da9121_map_mode,
	.ops = &da9121_buck_ops,
	.type = REGULATOR_VOLTAGE,
	.n_voltages = DA9121_N_VOLTAGES,
	.min_uV = DA9121_MIN_MV * 1000,
	.uV_step = DA9121_STEP_MV * 1000,
	.linear_min_sel = DA9121_MIN_SEL,
	.vsel_reg = DA9121_REG_BUCK_BUCK1_5,
	.vsel_mask = DA9121_MASK_BUCK_BUCKx_5_CHx_A_VOUT,
	.enable_reg = DA9121_REG_BUCK_BUCK1_0,
	.enable_mask = DA9121_MASK_BUCK_BUCKx_0_CHx_EN,
	/* Default value of BUCK_BUCK1_0.CH1_SRC_DVC_UP */
	.ramp_delay = 20000,
	/* tBUCK_EN */
	.enable_time = 20,
};

static const struct regulator_desc da9220_reg[2] = {
	{
		.id = DA9121_IDX_BUCK1,
		.name = "DA9220/DA9132 BUCK1",
		.of_match = "buck1",
		.of_parse_cb = da9121_of_parse_cb,
		.owner = THIS_MODULE,
		.regulators_node = of_match_ptr("regulators"),
		.of_map_mode = da9121_map_mode,
		.ops = &da9121_buck_ops,
		.type = REGULATOR_VOLTAGE,
		.n_voltages = DA9121_N_VOLTAGES,
		.min_uV = DA9121_MIN_MV * 1000,
		.uV_step = DA9121_STEP_MV * 1000,
		.linear_min_sel = DA9121_MIN_SEL,
		.enable_reg = DA9121_REG_BUCK_BUCK1_0,
		.enable_mask = DA9121_MASK_BUCK_BUCKx_0_CHx_EN,
		.vsel_reg = DA9121_REG_BUCK_BUCK1_5,
		.vsel_mask = DA9121_MASK_BUCK_BUCKx_5_CHx_A_VOUT,
	},
	{
		.id = DA9121_IDX_BUCK2,
		.name = "DA9220/DA9132 BUCK2",
		.of_match = "buck2",
		.of_parse_cb = da9121_of_parse_cb,
		.owner = THIS_MODULE,
		.regulators_node = of_match_ptr("regulators"),
		.of_map_mode = da9121_map_mode,
		.ops = &da9121_buck_ops,
		.type = REGULATOR_VOLTAGE,
		.n_voltages = DA9121_N_VOLTAGES,
		.min_uV = DA9121_MIN_MV * 1000,
		.uV_step = DA9121_STEP_MV * 1000,
		.linear_min_sel = DA9121_MIN_SEL,
		.enable_reg = DA9xxx_REG_BUCK_BUCK2_0,
		.enable_mask = DA9121_MASK_BUCK_BUCKx_0_CHx_EN,
		.vsel_reg = DA9xxx_REG_BUCK_BUCK2_5,
		.vsel_mask = DA9121_MASK_BUCK_BUCKx_5_CHx_A_VOUT,
	}
};

static const struct regulator_desc da9122_reg[2] = {
	{
		.id = DA9121_IDX_BUCK1,
		.name = "DA9122/DA9131 BUCK1",
		.of_match = "buck1",
		.of_parse_cb = da9121_of_parse_cb,
		.owner = THIS_MODULE,
		.regulators_node = of_match_ptr("regulators"),
		.of_map_mode = da9121_map_mode,
		.ops = &da9121_buck_ops,
		.type = REGULATOR_VOLTAGE,
		.n_voltages = DA9121_N_VOLTAGES,
		.min_uV = DA9121_MIN_MV * 1000,
		.uV_step = DA9121_STEP_MV * 1000,
		.linear_min_sel = DA9121_MIN_SEL,
		.enable_reg = DA9121_REG_BUCK_BUCK1_0,
		.enable_mask = DA9121_MASK_BUCK_BUCKx_0_CHx_EN,
		.vsel_reg = DA9121_REG_BUCK_BUCK1_5,
		.vsel_mask = DA9121_MASK_BUCK_BUCKx_5_CHx_A_VOUT,
	},
	{
		.id = DA9121_IDX_BUCK2,
		.name = "DA9122/DA9131 BUCK2",
		.of_match = "buck2",
		.of_parse_cb = da9121_of_parse_cb,
		.owner = THIS_MODULE,
		.regulators_node = of_match_ptr("regulators"),
		.of_map_mode = da9121_map_mode,
		.ops = &da9121_buck_ops,
		.type = REGULATOR_VOLTAGE,
		.n_voltages = DA9121_N_VOLTAGES,
		.min_uV = DA9121_MIN_MV * 1000,
		.uV_step = DA9121_STEP_MV * 1000,
		.linear_min_sel = DA9121_MIN_SEL,
		.enable_reg = DA9xxx_REG_BUCK_BUCK2_0,
		.enable_mask = DA9121_MASK_BUCK_BUCKx_0_CHx_EN,
		.vsel_reg = DA9xxx_REG_BUCK_BUCK2_5,
		.vsel_mask = DA9121_MASK_BUCK_BUCKx_5_CHx_A_VOUT,
	}
};

static const struct regulator_desc da9217_reg = {
	.id = DA9121_IDX_BUCK1,
	.name = "DA9217 BUCK1",
	.of_match = "buck1",
	.of_parse_cb = da9121_of_parse_cb,
	.owner = THIS_MODULE,
	.regulators_node = of_match_ptr("regulators"),
	.of_map_mode = da9121_map_mode,
	.ops = &da9121_buck_ops,
	.type = REGULATOR_VOLTAGE,
	.n_voltages = DA9121_N_VOLTAGES,
	.min_uV = DA9121_MIN_MV * 1000,
	.uV_step = DA9121_STEP_MV * 1000,
	.linear_min_sel = DA9121_MIN_SEL,
	.enable_reg = DA9121_REG_BUCK_BUCK1_0,
	.enable_mask = DA9121_MASK_BUCK_BUCKx_0_CHx_EN,
	.vsel_reg = DA9121_REG_BUCK_BUCK1_5,
	.vsel_mask = DA9121_MASK_BUCK_BUCKx_5_CHx_A_VOUT,
};

static const struct regulator_desc *local_da9121_regulators[][DA9121_IDX_MAX] = {
	[DA9121_TYPE_DA9121_DA9130] = { &da9121_reg, NULL },
	[DA9121_TYPE_DA9220_DA9132] = { &da9220_reg[0], &da9220_reg[1] },
	[DA9121_TYPE_DA9122_DA9131] = { &da9122_reg[0], &da9122_reg[1] },
	[DA9121_TYPE_DA9217] = { &da9217_reg, NULL },
};

static int da9121_set_regulator_config(struct da9121 *chip)
{
	struct regulator_config config = { };
	unsigned int max_matches = variant_parameters[chip->variant_id].num_bucks;
	int ret = 0;
	int i;

	for (i = 0; i < max_matches; i++) {
		const struct regulator_desc *regl_desc =
			local_da9121_regulators[chip->variant_id][i];

		config.dev = chip->dev;
		config.driver_data = chip;
		config.regmap = chip->regmap;

		chip->rdev[i] = devm_regulator_register(chip->dev,
					regl_desc, &config);
		if (IS_ERR(chip->rdev[i])) {
			dev_err(chip->dev, "Failed to register regulator %s, %d/%d\n",
				regl_desc->name, (i+1), max_matches);
			ret = PTR_ERR(chip->rdev[i]);
			goto error;
		}
	}

error:
	return ret;
}

/* DA9121 chip register model */
static const struct regmap_range da9121_1ch_readable_ranges[] = {
	regmap_reg_range(DA9121_REG_SYS_STATUS_0, DA9121_REG_SYS_MASK_3),
	regmap_reg_range(DA9121_REG_SYS_CONFIG_2, DA9121_REG_SYS_CONFIG_3),
	regmap_reg_range(DA9121_REG_SYS_GPIO0_0, DA9121_REG_SYS_GPIO2_1),
	regmap_reg_range(DA9121_REG_BUCK_BUCK1_0, DA9121_REG_BUCK_BUCK1_6),
	regmap_reg_range(DA9121_REG_OTP_DEVICE_ID, DA9121_REG_OTP_CONFIG_ID),
};

static const struct regmap_access_table da9121_1ch_readable_table = {
	.yes_ranges = da9121_1ch_readable_ranges,
	.n_yes_ranges = ARRAY_SIZE(da9121_1ch_readable_ranges),
};

static const struct regmap_range da9121_2ch_readable_ranges[] = {
	regmap_reg_range(DA9121_REG_SYS_STATUS_0, DA9121_REG_SYS_MASK_3),
	regmap_reg_range(DA9121_REG_SYS_CONFIG_2, DA9121_REG_SYS_CONFIG_3),
	regmap_reg_range(DA9121_REG_SYS_GPIO0_0, DA9121_REG_SYS_GPIO2_1),
	regmap_reg_range(DA9121_REG_BUCK_BUCK1_0, DA9121_REG_BUCK_BUCK1_7),
	regmap_reg_range(DA9xxx_REG_BUCK_BUCK2_0, DA9xxx_REG_BUCK_BUCK2_7),
	regmap_reg_range(DA9121_REG_OTP_DEVICE_ID, DA9121_REG_OTP_CONFIG_ID),
};

static const struct regmap_access_table da9121_2ch_readable_table = {
	.yes_ranges = da9121_2ch_readable_ranges,
	.n_yes_ranges = ARRAY_SIZE(da9121_2ch_readable_ranges),
};

static const struct regmap_range da9121_1ch_writeable_ranges[] = {
	regmap_reg_range(DA9121_REG_SYS_EVENT_0, DA9121_REG_SYS_MASK_3),
	regmap_reg_range(DA9121_REG_SYS_CONFIG_2, DA9121_REG_SYS_CONFIG_3),
	regmap_reg_range(DA9121_REG_SYS_GPIO0_0, DA9121_REG_SYS_GPIO2_1),
	regmap_reg_range(DA9121_REG_BUCK_BUCK1_0, DA9121_REG_BUCK_BUCK1_2),
	regmap_reg_range(DA9121_REG_BUCK_BUCK1_4, DA9121_REG_BUCK_BUCK1_6),
};

static const struct regmap_access_table da9121_1ch_writeable_table = {
	.yes_ranges = da9121_1ch_writeable_ranges,
	.n_yes_ranges = ARRAY_SIZE(da9121_1ch_writeable_ranges),
};

static const struct regmap_range da9121_2ch_writeable_ranges[] = {
	regmap_reg_range(DA9121_REG_SYS_EVENT_0, DA9121_REG_SYS_MASK_3),
	regmap_reg_range(DA9121_REG_SYS_CONFIG_2, DA9121_REG_SYS_CONFIG_3),
	regmap_reg_range(DA9121_REG_SYS_GPIO0_0, DA9121_REG_SYS_GPIO2_1),
	regmap_reg_range(DA9121_REG_BUCK_BUCK1_0, DA9121_REG_BUCK_BUCK1_2),
	regmap_reg_range(DA9121_REG_BUCK_BUCK1_4, DA9121_REG_BUCK_BUCK1_7),
	regmap_reg_range(DA9xxx_REG_BUCK_BUCK2_0, DA9xxx_REG_BUCK_BUCK2_2),
	regmap_reg_range(DA9xxx_REG_BUCK_BUCK2_4, DA9xxx_REG_BUCK_BUCK2_7),
};

static const struct regmap_access_table da9121_2ch_writeable_table = {
	.yes_ranges = da9121_2ch_writeable_ranges,
	.n_yes_ranges = ARRAY_SIZE(da9121_2ch_writeable_ranges),
};


static const struct regmap_range da9121_volatile_ranges[] = {
	regmap_reg_range(DA9121_REG_SYS_STATUS_0, DA9121_REG_SYS_EVENT_2),
	regmap_reg_range(DA9121_REG_SYS_GPIO0_0, DA9121_REG_SYS_GPIO2_1),
	regmap_reg_range(DA9121_REG_BUCK_BUCK1_0, DA9121_REG_BUCK_BUCK1_6),
};

static const struct regmap_access_table da9121_volatile_table = {
	.yes_ranges = da9121_volatile_ranges,
	.n_yes_ranges = ARRAY_SIZE(da9121_volatile_ranges),
};

/* DA9121 regmap config for 1 channel variants */
static struct regmap_config da9121_1ch_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = DA9121_REG_OTP_CONFIG_ID,
	.rd_table = &da9121_1ch_readable_table,
	.wr_table = &da9121_1ch_writeable_table,
	.volatile_table = &da9121_volatile_table,
	.cache_type = REGCACHE_RBTREE,
};

/* DA9121 regmap config for 2 channel variants */
static struct regmap_config da9121_2ch_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = DA9121_REG_OTP_CONFIG_ID,
	.rd_table = &da9121_2ch_readable_table,
	.wr_table = &da9121_2ch_writeable_table,
	.volatile_table = &da9121_volatile_table,
	.cache_type = REGCACHE_RBTREE,
};

static int da9121_check_device_type(struct i2c_client *i2c, struct da9121 *chip)
{
	u32 device_id;
	u8 chip_id = chip->variant_id;
	u32 variant_id;
	u8 variant_mrc, variant_vrc;
	char *type;
	const char *name;
	bool config_match = false;
	int ret = 0;

	ret = regmap_read(chip->regmap, DA9121_REG_OTP_DEVICE_ID, &device_id);
	if (ret < 0) {
		dev_err(chip->dev, "Cannot read device ID: %d\n", ret);
		goto error;
	}

	ret = regmap_read(chip->regmap, DA9121_REG_OTP_VARIANT_ID, &variant_id);
	if (ret < 0) {
		dev_err(chip->dev, "Cannot read variant ID: %d\n", ret);
		goto error;
	}

	if (device_id != DA9121_DEVICE_ID) {
		dev_err(chip->dev, "Invalid device ID: 0x%02x\n", device_id);
		ret = -ENODEV;
		goto error;
	}

	variant_vrc = variant_id & DA9121_MASK_OTP_VARIANT_ID_VRC;

	switch (variant_vrc) {
	case DA9121_VARIANT_VRC:
		type = "DA9121/DA9130";
		config_match = (chip_id == DA9121_TYPE_DA9121_DA9130);
		break;
	case DA9220_VARIANT_VRC:
		type = "DA9220/DA9132";
		config_match = (chip_id == DA9121_TYPE_DA9220_DA9132);
		break;
	case DA9122_VARIANT_VRC:
		type = "DA9122/DA9131";
		config_match = (chip_id == DA9121_TYPE_DA9122_DA9131);
		break;
	case DA9217_VARIANT_VRC:
		type = "DA9217";
		config_match = (chip_id == DA9121_TYPE_DA9217);
		break;
	default:
		type = "Unknown";
		break;
	}

	dev_info(chip->dev,
		 "Device detected (device-ID: 0x%02X, var-ID: 0x%02X, %s)\n",
		 device_id, variant_id, type);

	if (!config_match) {
		dev_err(chip->dev, "Device tree configuration '%s' does not match detected device.\n", name);
		ret = -EINVAL;
		goto error;
	}

	variant_mrc = (variant_id & DA9121_MASK_OTP_VARIANT_ID_MRC)
			>> DA9121_SHIFT_OTP_VARIANT_ID_MRC;

	if ((device_id == DA9121_DEVICE_ID) &&
	    (variant_mrc < DA9121_VARIANT_MRC_BASE)) {
		dev_err(chip->dev,
			"Cannot support variant MRC: 0x%02X\n", variant_mrc);
		ret = -EINVAL;
	}
error:
	return ret;
}

static int da9121_assign_chip_model(struct i2c_client *i2c,
			struct da9121 *chip)
{
	struct regmap_config *regmap;
	int ret = 0;

	chip->dev = &i2c->dev;

	switch (chip->variant_id) {
	case DA9121_TYPE_DA9121_DA9130:
		fallthrough;
	case DA9121_TYPE_DA9217:
		regmap = &da9121_1ch_regmap_config;
		break;
	case DA9121_TYPE_DA9122_DA9131:
		fallthrough;
	case DA9121_TYPE_DA9220_DA9132:
		regmap = &da9121_2ch_regmap_config;
		break;
	}

	/* Set these up for of_regulator_match call which may want .of_map_modes */
	da9121_matches[0].desc = local_da9121_regulators[chip->variant_id][0];
	da9121_matches[1].desc = local_da9121_regulators[chip->variant_id][1];

	chip->regmap = devm_regmap_init_i2c(i2c, regmap);
	if (IS_ERR(chip->regmap)) {
		ret = PTR_ERR(chip->regmap);
		dev_err(chip->dev, "Failed to configure a register map: %d\n",
			ret);
	}

	ret = da9121_check_device_type(i2c, chip);

	return ret;
}

static const struct of_device_id da9121_dt_ids[] = {
	{ .compatible = "dlg,da9121", .data = (void *) DA9121_TYPE_DA9121_DA9130 },
	{ .compatible = "dlg,da9130", .data = (void *) DA9121_TYPE_DA9121_DA9130 },
	{ .compatible = "dlg,da9217", .data = (void *) DA9121_TYPE_DA9217 },
	{ .compatible = "dlg,da9122", .data = (void *) DA9121_TYPE_DA9122_DA9131 },
	{ .compatible = "dlg,da9131", .data = (void *) DA9121_TYPE_DA9122_DA9131 },
	{ .compatible = "dlg,da9220", .data = (void *) DA9121_TYPE_DA9220_DA9132 },
	{ .compatible = "dlg,da9132", .data = (void *) DA9121_TYPE_DA9220_DA9132 },
	{ }
};
MODULE_DEVICE_TABLE(of, da9121_dt_ids);

static inline int da9121_of_get_id(struct device *dev)
{
	const struct of_device_id *id = of_match_device(da9121_dt_ids, dev);

	if (!id) {
		dev_err(dev, "%s: Failed\n", __func__);
		return -EINVAL;
	}
	return (uintptr_t)id->data;
}

static int da9121_i2c_probe(struct i2c_client *i2c,
			    const struct i2c_device_id *id)
{
	struct da9121 *chip;
	int ret = 0;

	chip = devm_kzalloc(&i2c->dev, sizeof(struct da9121), GFP_KERNEL);
	if (!chip) {
		ret = -ENOMEM;
		goto error;
	}

	chip->pdata = i2c->dev.platform_data;
	chip->variant_id = da9121_of_get_id(&i2c->dev);

	ret = da9121_assign_chip_model(i2c, chip);
	if (ret < 0)
		goto error;

	ret = da9121_set_regulator_config(chip);

error:
	return ret;
}

static const struct i2c_device_id da9121_i2c_id[] = {
	{"da9121", DA9121_TYPE_DA9121_DA9130},
	{"da9130", DA9121_TYPE_DA9121_DA9130},
	{"da9217", DA9121_TYPE_DA9217},
	{"da9122", DA9121_TYPE_DA9122_DA9131},
	{"da9131", DA9121_TYPE_DA9122_DA9131},
	{"da9220", DA9121_TYPE_DA9220_DA9132},
	{"da9132", DA9121_TYPE_DA9220_DA9132},
	{},
};
MODULE_DEVICE_TABLE(i2c, da9121_i2c_id);

static struct i2c_driver da9121_regulator_driver = {
	.driver = {
		.name = "da9121",
		.of_match_table = of_match_ptr(da9121_dt_ids),
	},
	.probe = da9121_i2c_probe,
	.id_table = da9121_i2c_id,
};

module_i2c_driver(da9121_regulator_driver);

MODULE_LICENSE("GPL v2");