// SPDX-License-Identifier: GPL-2.0
//
// AWINIC AW37503 Regulator Driver
//
// Copyright (C) 2023 awinic. All Rights Reserved
//
// Author: <like@awinic.com>

#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>

#define AW37503_REG_VPOS		0x00
#define AW37503_REG_VNEG		0x01
#define AW37503_REG_APPS		0x03
#define AW37503_REG_CONTROL		0x04
#define AW37503_REG_WPRTEN		0x21

#define AW37503_VOUT_MASK		0x1F
#define AW37503_VOUT_N_VOLTAGE		0x15
#define AW37503_VOUT_VMIN		4000000
#define AW37503_VOUT_VMAX		6000000
#define AW37503_VOUT_STEP		100000

#define AW37503_REG_APPS_DIS_VPOS	BIT(1)
#define AW37503_REG_APPS_DIS_VNEG	BIT(0)

#define AW37503_REGULATOR_ID_VPOS	0
#define AW37503_REGULATOR_ID_VNEG	1
#define AW37503_MAX_REGULATORS		2

struct aw37503_reg_pdata {
	struct gpio_desc *en_gpiod;
	int ena_gpio_state;
};

struct aw37503_regulator {
	struct device *dev;
	struct aw37503_reg_pdata reg_pdata[AW37503_MAX_REGULATORS];
};

static int aw37503_regulator_enable(struct regulator_dev *rdev)
{
	struct aw37503_regulator *chip = rdev_get_drvdata(rdev);
	int id = rdev_get_id(rdev);
	struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[id];
	int ret;

	if (!IS_ERR(rpdata->en_gpiod)) {
		gpiod_set_value_cansleep(rpdata->en_gpiod, 1);
		rpdata->ena_gpio_state = 1;
	}

	/* Hardware automatically enable discharge bit in enable */
	if (rdev->constraints->active_discharge ==
			REGULATOR_ACTIVE_DISCHARGE_DISABLE) {
		ret = regulator_set_active_discharge_regmap(rdev, false);
		if (ret < 0) {
			dev_err(chip->dev, "Failed to disable active discharge: %d\n",
				ret);
			return ret;
		}
	}

	return 0;
}

static int aw37503_regulator_disable(struct regulator_dev *rdev)
{
	struct aw37503_regulator *chip = rdev_get_drvdata(rdev);
	int id = rdev_get_id(rdev);
	struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[id];

	if (!IS_ERR(rpdata->en_gpiod)) {
		gpiod_set_value_cansleep(rpdata->en_gpiod, 0);
		rpdata->ena_gpio_state = 0;
	}

	return 0;
}

static int aw37503_regulator_is_enabled(struct regulator_dev *rdev)
{
	struct aw37503_regulator *chip = rdev_get_drvdata(rdev);
	int id = rdev_get_id(rdev);
	struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[id];

	if (!IS_ERR(rpdata->en_gpiod))
		return rpdata->ena_gpio_state;

	return 1;
}

static const struct regulator_ops aw37503_regulator_ops = {
	.enable = aw37503_regulator_enable,
	.disable = aw37503_regulator_disable,
	.is_enabled = aw37503_regulator_is_enabled,
	.list_voltage = regulator_list_voltage_linear,
	.map_voltage = regulator_map_voltage_linear,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.set_active_discharge = regulator_set_active_discharge_regmap,
};

static int aw37503_of_parse_cb(struct device_node *np,
				const struct regulator_desc *desc,
				struct regulator_config *config)
{
	struct aw37503_regulator *chip = config->driver_data;
	struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[desc->id];
	int ret;

	rpdata->en_gpiod = devm_fwnode_gpiod_get(chip->dev, of_fwnode_handle(np),
						 "enable", GPIOD_OUT_LOW,
						 "enable");

	if (IS_ERR(rpdata->en_gpiod)) {
		ret = PTR_ERR(rpdata->en_gpiod);

		/* Ignore the error other than probe defer */
		if (ret == -EPROBE_DEFER)
			return ret;
		return 0;
	}

	return 0;
}

#define AW37503_REGULATOR_DESC(_id, _name)		\
	[AW37503_REGULATOR_ID_##_id] = {		\
		.name = "aw37503-"#_name,		\
		.supply_name = "vin",			\
		.id = AW37503_REGULATOR_ID_##_id,	\
		.of_match = of_match_ptr(#_name),	\
		.of_parse_cb = aw37503_of_parse_cb,	\
		.ops = &aw37503_regulator_ops,		\
		.n_voltages = AW37503_VOUT_N_VOLTAGE,	\
		.min_uV = AW37503_VOUT_VMIN,		\
		.uV_step = AW37503_VOUT_STEP,		\
		.enable_time = 500,			\
		.vsel_mask = AW37503_VOUT_MASK,	\
		.vsel_reg = AW37503_REG_##_id,		\
		.active_discharge_off = 0,			\
		.active_discharge_on = AW37503_REG_APPS_DIS_##_id, \
		.active_discharge_mask = AW37503_REG_APPS_DIS_##_id, \
		.active_discharge_reg = AW37503_REG_APPS, \
		.type = REGULATOR_VOLTAGE,		\
		.owner = THIS_MODULE,			\
	}

static const struct regulator_desc aw_regs_desc[AW37503_MAX_REGULATORS] = {
	AW37503_REGULATOR_DESC(VPOS, outp),
	AW37503_REGULATOR_DESC(VNEG, outn),
};

static const struct regmap_range aw37503_no_reg_ranges[] = {
	regmap_reg_range(AW37503_REG_CONTROL + 1,
			 AW37503_REG_WPRTEN - 1),
};

static const struct regmap_access_table aw37503_no_reg_table = {
	.no_ranges = aw37503_no_reg_ranges,
	.n_no_ranges = ARRAY_SIZE(aw37503_no_reg_ranges),
};

static const struct regmap_config aw37503_regmap_config = {
	.reg_bits	= 8,
	.val_bits	= 8,
	.max_register	= AW37503_REG_WPRTEN,
	.rd_table	= &aw37503_no_reg_table,
	.wr_table	= &aw37503_no_reg_table,
};

static int aw37503_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct aw37503_regulator *chip;
	struct regulator_dev *rdev;
	struct regmap *regmap;
	struct regulator_config config = { };
	int id;

	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
	if (!chip)
		return -ENOMEM;

	regmap = devm_regmap_init_i2c(client, &aw37503_regmap_config);
	if (IS_ERR(regmap))
		return dev_err_probe(dev, PTR_ERR(regmap),
				     "Failed to init regmap\n");

	i2c_set_clientdata(client, chip);
	chip->dev = dev;

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

	for (id = 0; id < AW37503_MAX_REGULATORS; ++id) {
		rdev = devm_regulator_register(dev, &aw_regs_desc[id],
					       &config);
		if (IS_ERR(rdev))
			return dev_err_probe(dev, PTR_ERR(rdev),
					     "Failed to register regulator %s\n",
					     aw_regs_desc[id].name);
	}
	return 0;
}

static const struct i2c_device_id aw37503_id[] = {
	{.name = "aw37503",},
	{},
};
MODULE_DEVICE_TABLE(i2c, aw37503_id);

static const struct of_device_id aw37503_of_match[] = {
	{.compatible = "awinic,aw37503",},
	{ /* Sentinel */ },
};

MODULE_DEVICE_TABLE(of, aw37503_of_match);

static struct i2c_driver aw37503_i2c_driver = {
	.driver = {
		.name = "aw37503",
		.of_match_table = aw37503_of_match,
	},
	.probe = aw37503_probe,
	.id_table = aw37503_id,
};

module_i2c_driver(aw37503_i2c_driver);

MODULE_DESCRIPTION("aw37503 regulator driver");
MODULE_AUTHOR("Alec Li <like@awinic.com>");
MODULE_LICENSE("GPL");