// SPDX-License-Identifier: GPL-2.0+

#include <linux/bits.h>
#include <linux/gpio/consumer.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>

enum {
	MT6370_IDX_DSVBOOST = 0,
	MT6370_IDX_DSVPOS,
	MT6370_IDX_DSVNEG,
	MT6370_IDX_VIBLDO,
	MT6370_MAX_IDX
};

#define MT6370_REG_LDO_CFG	0x180
#define MT6370_REG_LDO_VOUT	0x181
#define MT6370_REG_DB_CTRL1	0x1B0
#define MT6370_REG_DB_CTRL2	0x1B1
#define MT6370_REG_DB_VBST	0x1B2
#define MT6370_REG_DB_VPOS	0x1B3
#define MT6370_REG_DB_VNEG	0x1B4
#define MT6370_REG_LDO_STAT	0x1DC
#define MT6370_REG_DB_STAT	0x1DF

#define MT6370_LDOOMS_MASK	BIT(7)
#define MT6370_LDOEN_MASK	BIT(7)
#define MT6370_LDOVOUT_MASK	GENMASK(3, 0)
#define MT6370_DBPERD_MASK	(BIT(7) | BIT(4))
#define MT6370_DBEXTEN_MASK	BIT(0)
#define MT6370_DBVPOSEN_MASK	BIT(6)
#define MT6370_DBVPOSDISG_MASK	BIT(5)
#define MT6370_DBVNEGEN_MASK	BIT(3)
#define MT6370_DBVNEGDISG_MASK	BIT(2)
#define MT6370_DBALLON_MASK	(MT6370_DBVPOSEN_MASK | MT6370_DBVNEGEN_MASK)
#define MT6370_DBSLEW_MASK	GENMASK(7, 6)
#define MT6370_DBVOUT_MASK	GENMASK(5, 0)
#define MT6370_LDOOC_EVT_MASK	BIT(7)
#define MT6370_POSSCP_EVT_MASK	BIT(7)
#define MT6370_NEGSCP_EVT_MASK	BIT(6)
#define MT6370_BSTOCP_EVT_MASK	BIT(5)
#define MT6370_POSOCP_EVT_MASK	BIT(4)
#define MT6370_NEGOCP_EVT_MASK	BIT(3)

#define MT6370_LDO_MINUV	1600000
#define MT6370_LDO_STPUV	200000
#define MT6370_LDO_N_VOLT	13
#define MT6370_DBVBOOST_MINUV	4000000
#define MT6370_DBVBOOST_STPUV	50000
#define MT6370_DBVBOOST_N_VOLT	45
#define MT6370_DBVOUT_MINUV	4000000
#define MT6370_DBVOUT_STPUV	50000
#define MT6370_DBVOUT_N_VOLT	41

struct mt6370_priv {
	struct device *dev;
	struct regmap *regmap;
	struct regulator_dev *rdev[MT6370_MAX_IDX];
	bool use_external_ctrl;
};

static const unsigned int mt6370_vpos_ramp_tbl[] = { 8540, 5840, 4830, 3000 };
static const unsigned int mt6370_vneg_ramp_tbl[] = { 10090, 6310, 5050, 3150 };

static int mt6370_get_error_flags(struct regulator_dev *rdev,
				  unsigned int *flags)
{
	struct regmap *regmap = rdev_get_regmap(rdev);
	unsigned int stat_reg, stat, rpt_flags = 0;
	int rid = rdev_get_id(rdev), ret;

	if (rid == MT6370_IDX_VIBLDO)
		stat_reg = MT6370_REG_LDO_STAT;
	else
		stat_reg = MT6370_REG_DB_STAT;

	ret = regmap_read(regmap, stat_reg, &stat);
	if (ret)
		return ret;

	switch (rid) {
	case MT6370_IDX_DSVBOOST:
		if (stat & MT6370_BSTOCP_EVT_MASK)
			rpt_flags |= REGULATOR_ERROR_OVER_CURRENT;
		break;
	case MT6370_IDX_DSVPOS:
		if (stat & MT6370_POSSCP_EVT_MASK)
			rpt_flags |= REGULATOR_ERROR_UNDER_VOLTAGE;

		if (stat & MT6370_POSOCP_EVT_MASK)
			rpt_flags |= REGULATOR_ERROR_OVER_CURRENT;
		break;
	case MT6370_IDX_DSVNEG:
		if (stat & MT6370_NEGSCP_EVT_MASK)
			rpt_flags |= REGULATOR_ERROR_UNDER_VOLTAGE;

		if (stat & MT6370_NEGOCP_EVT_MASK)
			rpt_flags |= REGULATOR_ERROR_OVER_CURRENT;
		break;
	default:
		if (stat & MT6370_LDOOC_EVT_MASK)
			rpt_flags |= REGULATOR_ERROR_OVER_CURRENT;
		break;
	}

	*flags = rpt_flags;
	return 0;
}

static const struct regulator_ops mt6370_dbvboost_ops = {
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.list_voltage = regulator_list_voltage_linear,
	.get_bypass = regulator_get_bypass_regmap,
	.set_bypass = regulator_set_bypass_regmap,
	.get_error_flags = mt6370_get_error_flags,
};

static const struct regulator_ops mt6370_dbvout_ops = {
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.list_voltage = regulator_list_voltage_linear,
	.is_enabled = regulator_is_enabled_regmap,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.set_active_discharge = regulator_set_active_discharge_regmap,
	.set_ramp_delay = regulator_set_ramp_delay_regmap,
	.get_error_flags = mt6370_get_error_flags,
};

static const struct regulator_ops mt6370_ldo_ops = {
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.list_voltage = regulator_list_voltage_linear,
	.is_enabled = regulator_is_enabled_regmap,
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.set_active_discharge = regulator_set_active_discharge_regmap,
	.get_error_flags = mt6370_get_error_flags,
};

static int mt6370_of_parse_cb(struct device_node *np,
			      const struct regulator_desc *desc,
			      struct regulator_config *config)
{
	struct mt6370_priv *priv = config->driver_data;
	struct gpio_desc *enable_gpio;
	int ret;

	enable_gpio = fwnode_gpiod_get_index(of_fwnode_handle(np), "enable", 0,
					     GPIOD_OUT_HIGH |
					     GPIOD_FLAGS_BIT_NONEXCLUSIVE,
					     desc->name);
	if (IS_ERR(enable_gpio)) {
		config->ena_gpiod = NULL;
		return 0;
	}

	/*
	 * RG control by default
	 * Only if all are using external pin, change all by external control
	 */
	if (priv->use_external_ctrl) {
		ret = regmap_update_bits(priv->regmap, MT6370_REG_DB_CTRL1,
					 MT6370_DBEXTEN_MASK,
					 MT6370_DBEXTEN_MASK);
		if (ret)
			return ret;
	}

	config->ena_gpiod = enable_gpio;
	priv->use_external_ctrl = true;
	return 0;
}

static const struct regulator_desc mt6370_regulator_descs[] = {
	{
		.name = "mt6370-dsv-vbst",
		.of_match = of_match_ptr("dsvbst"),
		.regulators_node = of_match_ptr("regulators"),
		.id = MT6370_IDX_DSVBOOST,
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
		.ops = &mt6370_dbvboost_ops,
		.min_uV = MT6370_DBVBOOST_MINUV,
		.uV_step = MT6370_DBVBOOST_STPUV,
		.n_voltages = MT6370_DBVBOOST_N_VOLT,
		.vsel_reg = MT6370_REG_DB_VBST,
		.vsel_mask = MT6370_DBVOUT_MASK,
		.bypass_reg = MT6370_REG_DB_CTRL1,
		.bypass_mask = MT6370_DBPERD_MASK,
		.bypass_val_on = MT6370_DBPERD_MASK,
	},
	{
		.name = "mt6370-dsv-vpos",
		.of_match = of_match_ptr("dsvpos"),
		.regulators_node = of_match_ptr("regulators"),
		.id = MT6370_IDX_DSVPOS,
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
		.of_parse_cb = mt6370_of_parse_cb,
		.ops = &mt6370_dbvout_ops,
		.min_uV = MT6370_DBVOUT_MINUV,
		.uV_step = MT6370_DBVOUT_STPUV,
		.n_voltages = MT6370_DBVOUT_N_VOLT,
		.vsel_reg = MT6370_REG_DB_VPOS,
		.vsel_mask = MT6370_DBVOUT_MASK,
		.enable_reg = MT6370_REG_DB_CTRL2,
		.enable_mask = MT6370_DBVPOSEN_MASK,
		.ramp_reg = MT6370_REG_DB_VPOS,
		.ramp_mask = MT6370_DBSLEW_MASK,
		.ramp_delay_table = mt6370_vpos_ramp_tbl,
		.n_ramp_values = ARRAY_SIZE(mt6370_vpos_ramp_tbl),
		.active_discharge_reg = MT6370_REG_DB_CTRL2,
		.active_discharge_mask = MT6370_DBVPOSDISG_MASK,
		.active_discharge_on = MT6370_DBVPOSDISG_MASK,
	},
	{
		.name = "mt6370-dsv-vneg",
		.of_match = of_match_ptr("dsvneg"),
		.regulators_node = of_match_ptr("regulators"),
		.id = MT6370_IDX_DSVNEG,
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
		.of_parse_cb = mt6370_of_parse_cb,
		.ops = &mt6370_dbvout_ops,
		.min_uV = MT6370_DBVOUT_MINUV,
		.uV_step = MT6370_DBVOUT_STPUV,
		.n_voltages = MT6370_DBVOUT_N_VOLT,
		.vsel_reg = MT6370_REG_DB_VNEG,
		.vsel_mask = MT6370_DBVOUT_MASK,
		.enable_reg = MT6370_REG_DB_CTRL2,
		.enable_mask = MT6370_DBVNEGEN_MASK,
		.ramp_reg = MT6370_REG_DB_VNEG,
		.ramp_mask = MT6370_DBSLEW_MASK,
		.ramp_delay_table = mt6370_vneg_ramp_tbl,
		.n_ramp_values = ARRAY_SIZE(mt6370_vneg_ramp_tbl),
		.active_discharge_reg = MT6370_REG_DB_CTRL2,
		.active_discharge_mask = MT6370_DBVNEGDISG_MASK,
		.active_discharge_on = MT6370_DBVNEGDISG_MASK,
	},
	{
		.name = "mt6370-vib-ldo",
		.of_match = of_match_ptr("vibldo"),
		.regulators_node = of_match_ptr("regulators"),
		.id = MT6370_IDX_VIBLDO,
		.type = REGULATOR_VOLTAGE,
		.owner = THIS_MODULE,
		.ops = &mt6370_ldo_ops,
		.min_uV = MT6370_LDO_MINUV,
		.uV_step = MT6370_LDO_STPUV,
		.n_voltages = MT6370_LDO_N_VOLT,
		.vsel_reg = MT6370_REG_LDO_VOUT,
		.vsel_mask = MT6370_LDOVOUT_MASK,
		.enable_reg = MT6370_REG_LDO_VOUT,
		.enable_mask = MT6370_LDOEN_MASK,
		.active_discharge_reg = MT6370_REG_LDO_CFG,
		.active_discharge_mask = MT6370_LDOOMS_MASK,
		.active_discharge_on = MT6370_LDOOMS_MASK,
	}
};

static irqreturn_t mt6370_scp_handler(int irq, void *data)
{
	struct regulator_dev *rdev = data;

	regulator_notifier_call_chain(rdev, REGULATOR_EVENT_UNDER_VOLTAGE,
				      NULL);
	return IRQ_HANDLED;
}

static irqreturn_t mt6370_ocp_handler(int irq, void *data)
{
	struct regulator_dev *rdev = data;

	regulator_notifier_call_chain(rdev, REGULATOR_EVENT_OVER_CURRENT, NULL);
	return IRQ_HANDLED;
}

static int mt6370_regulator_irq_register(struct mt6370_priv *priv)
{
	struct platform_device *pdev = to_platform_device(priv->dev);
	static const struct {
		const char *name;
		int rid;
		irq_handler_t handler;
	} mt6370_irqs[] = {
		{ "db_vpos_scp", MT6370_IDX_DSVPOS, mt6370_scp_handler },
		{ "db_vneg_scp", MT6370_IDX_DSVNEG, mt6370_scp_handler },
		{ "db_vbst_ocp", MT6370_IDX_DSVBOOST, mt6370_ocp_handler },
		{ "db_vpos_ocp", MT6370_IDX_DSVPOS,  mt6370_ocp_handler },
		{ "db_vneg_ocp", MT6370_IDX_DSVNEG, mt6370_ocp_handler },
		{ "ldo_oc", MT6370_IDX_VIBLDO, mt6370_ocp_handler }
	};
	struct regulator_dev *rdev;
	int i, irq, ret;

	for (i = 0; i < ARRAY_SIZE(mt6370_irqs); i++) {
		irq = platform_get_irq_byname(pdev, mt6370_irqs[i].name);

		rdev = priv->rdev[mt6370_irqs[i].rid];

		ret = devm_request_threaded_irq(priv->dev, irq, NULL,
						mt6370_irqs[i].handler, 0,
						mt6370_irqs[i].name, rdev);
		if (ret) {
			dev_err(priv->dev,
				"Failed to register (%d) interrupt\n", i);
			return ret;
		}
	}

	return 0;
}

static int mt6370_regualtor_register(struct mt6370_priv *priv)
{
	struct regulator_dev *rdev;
	struct regulator_config cfg = {};
	struct device *parent = priv->dev->parent;
	int i;

	cfg.dev = parent;
	cfg.driver_data = priv;

	for (i = 0; i < MT6370_MAX_IDX; i++) {
		rdev = devm_regulator_register(priv->dev,
					       mt6370_regulator_descs + i,
					       &cfg);
		if (IS_ERR(rdev)) {
			dev_err(priv->dev,
				"Failed to register (%d) regulator\n", i);
			return PTR_ERR(rdev);
		}

		priv->rdev[i] = rdev;
	}

	return 0;
}

static int mt6370_regulator_probe(struct platform_device *pdev)
{
	struct mt6370_priv *priv;
	int ret;

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->dev = &pdev->dev;

	priv->regmap = dev_get_regmap(pdev->dev.parent, NULL);
	if (!priv->regmap) {
		dev_err(&pdev->dev, "Failed to init regmap\n");
		return -ENODEV;
	}

	ret = mt6370_regualtor_register(priv);
	if (ret)
		return ret;

	return mt6370_regulator_irq_register(priv);
}

static const struct platform_device_id mt6370_devid_table[] = {
	{ "mt6370-regulator", 0},
	{}
};
MODULE_DEVICE_TABLE(platform, mt6370_devid_table);

static struct platform_driver mt6370_regulator_driver = {
	.driver = {
		.name = "mt6370-regulator",
		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
	},
	.id_table = mt6370_devid_table,
	.probe = mt6370_regulator_probe,
};
module_platform_driver(mt6370_regulator_driver);

MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
MODULE_DESCRIPTION("Mediatek MT6370 Regulator Driver");
MODULE_LICENSE("GPL v2"