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

#include <linux/bitops.h>
#include <linux/bitfield.h>
#include <linux/util_macros.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/mod_devicetable.h>

/* Register */
#define RTQ2208_REG_GLOBAL_INT1			0x12
#define RTQ2208_REG_FLT_RECORDBUCK_CB		0x18
#define RTQ2208_REG_GLOBAL_INT1_MASK		0x1D
#define RTQ2208_REG_FLT_MASKBUCK_CB		0x1F
#define RTQ2208_REG_BUCK_C_CFG0			0x32
#define RTQ2208_REG_BUCK_B_CFG0			0x42
#define RTQ2208_REG_BUCK_A_CFG0			0x52
#define RTQ2208_REG_BUCK_D_CFG0			0x62
#define RTQ2208_REG_BUCK_G_CFG0			0x72
#define RTQ2208_REG_BUCK_F_CFG0			0x82
#define RTQ2208_REG_BUCK_E_CFG0			0x92
#define RTQ2208_REG_BUCK_H_CFG0			0xA2
#define RTQ2208_REG_LDO1_CFG			0xB1
#define RTQ2208_REG_LDO2_CFG			0xC1

/* Mask */
#define RTQ2208_BUCK_NR_MTP_SEL_MASK		GENMASK(7, 0)
#define RTQ2208_BUCK_EN_NR_MTP_SEL0_MASK	BIT(0)
#define RTQ2208_BUCK_EN_NR_MTP_SEL1_MASK	BIT(1)
#define RTQ2208_BUCK_RSPUP_MASK			GENMASK(6, 4)
#define RTQ2208_BUCK_RSPDN_MASK			GENMASK(2, 0)
#define RTQ2208_BUCK_NRMODE_MASK		BIT(5)
#define RTQ2208_BUCK_STRMODE_MASK		BIT(5)
#define RTQ2208_BUCK_EN_STR_MASK		BIT(0)
#define RTQ2208_LDO_EN_STR_MASK			BIT(7)
#define RTQ2208_EN_DIS_MASK			BIT(0)
#define RTQ2208_BUCK_RAMP_SEL_MASK		GENMASK(2, 0)
#define RTQ2208_HD_INT_MASK			BIT(0)

/* Size */
#define RTQ2208_VOUT_MAXNUM			256
#define RTQ2208_BUCK_NUM_IRQ_REGS		5
#define RTQ2208_STS_NUM_IRQ_REGS		2

/* Value */
#define RTQ2208_RAMP_VALUE_MIN_uV		500
#define RTQ2208_RAMP_VALUE_MAX_uV		64000

#define RTQ2208_BUCK_MASK(uv_irq, ov_irq)	(1 << ((uv_irq) % 8) | 1 << ((ov_irq) % 8))

enum {
	RTQ2208_BUCK_B = 0,
	RTQ2208_BUCK_C,
	RTQ2208_BUCK_D,
	RTQ2208_BUCK_A,
	RTQ2208_BUCK_F,
	RTQ2208_BUCK_G,
	RTQ2208_BUCK_H,
	RTQ2208_BUCK_E,
	RTQ2208_LDO2,
	RTQ2208_LDO1,
	RTQ2208_LDO_MAX,
};

enum {
	RTQ2208_AUTO_MODE = 0,
	RTQ2208_FCCM,
};

struct rtq2208_regulator_desc {
	struct regulator_desc desc;
	unsigned int mtp_sel_reg;
	unsigned int mtp_sel_mask;
	unsigned int mode_reg;
	unsigned int mode_mask;
	unsigned int suspend_config_reg;
	unsigned int suspend_enable_mask;
	unsigned int suspend_mode_mask;
};

struct rtq2208_rdev_map {
	struct regulator_dev *rdev[RTQ2208_LDO_MAX];
	struct regmap *regmap;
	struct device *dev;
};

/* set Normal Auto/FCCM mode */
static int rtq2208_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
	const struct rtq2208_regulator_desc *rdesc =
		(const struct rtq2208_regulator_desc *)rdev->desc;
	unsigned int val, shift;

	switch (mode) {
	case REGULATOR_MODE_NORMAL:
		val = RTQ2208_AUTO_MODE;
		break;
	case REGULATOR_MODE_FAST:
		val = RTQ2208_FCCM;
		break;
	default:
		return -EINVAL;
	}

	shift = ffs(rdesc->mode_mask) - 1;
	return regmap_update_bits(rdev->regmap, rdesc->mode_reg,
				  rdesc->mode_mask, val << shift);
}

static unsigned int rtq2208_get_mode(struct regulator_dev *rdev)
{
	const struct rtq2208_regulator_desc *rdesc =
		(const struct rtq2208_regulator_desc *)rdev->desc;
	unsigned int mode_val;
	int ret;

	ret = regmap_read(rdev->regmap, rdesc->mode_reg, &mode_val);
	if (ret)
		return REGULATOR_MODE_INVALID;

	return (mode_val & rdesc->mode_mask) ? REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
}

static int rtq2208_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
{
	const struct regulator_desc *desc = rdev->desc;
	unsigned int sel = 0, val;

	ramp_delay = max(ramp_delay, RTQ2208_RAMP_VALUE_MIN_uV);
	ramp_delay = min(ramp_delay, RTQ2208_RAMP_VALUE_MAX_uV);

	ramp_delay /= RTQ2208_RAMP_VALUE_MIN_uV;

	/*
	 * fls(ramp_delay) - 1: doing LSB shift, let it starts from 0
	 *
	 * RTQ2208_BUCK_RAMP_SEL_MASK - sel: doing descending order shifting.
	 * Because the relation of seleltion and value is like that
	 *
	 * seletion: value
	 * 000: 64mv
	 * 001: 32mv
	 * ...
	 * 111: 0.5mv
	 *
	 * For example, if I would like to select 64mv, the fls(ramp_delay) - 1 will be 0b111,
	 * and I need to use 0b111 - sel to do the shifting
	 */

	sel = fls(ramp_delay) - 1;
	sel = RTQ2208_BUCK_RAMP_SEL_MASK - sel;

	val = FIELD_PREP(RTQ2208_BUCK_RSPUP_MASK, sel) | FIELD_PREP(RTQ2208_BUCK_RSPDN_MASK, sel);

	return regmap_update_bits(rdev->regmap, desc->ramp_reg,
				  RTQ2208_BUCK_RSPUP_MASK | RTQ2208_BUCK_RSPDN_MASK, val);
}

static int rtq2208_set_suspend_enable(struct regulator_dev *rdev)
{
	const struct rtq2208_regulator_desc *rdesc =
		(const struct rtq2208_regulator_desc *)rdev->desc;

	return regmap_set_bits(rdev->regmap, rdesc->suspend_config_reg, rdesc->suspend_enable_mask);
}

static int rtq2208_set_suspend_disable(struct regulator_dev *rdev)
{
	const struct rtq2208_regulator_desc *rdesc =
		(const struct rtq2208_regulator_desc *)rdev->desc;

	return regmap_update_bits(rdev->regmap, rdesc->suspend_config_reg, rdesc->suspend_enable_mask, 0);
}

static int rtq2208_set_suspend_mode(struct regulator_dev *rdev, unsigned int mode)
{
	const struct rtq2208_regulator_desc *rdesc =
		(const struct rtq2208_regulator_desc *)rdev->desc;
	unsigned int val, shift;

	switch (mode) {
	case REGULATOR_MODE_NORMAL:
		val = RTQ2208_AUTO_MODE;
		break;
	case REGULATOR_MODE_FAST:
		val = RTQ2208_FCCM;
		break;
	default:
		return -EINVAL;
	}

	shift = ffs(rdesc->suspend_mode_mask) - 1;

	return regmap_update_bits(rdev->regmap, rdesc->suspend_config_reg,
			rdesc->suspend_mode_mask, val << shift);
}

static const struct regulator_ops rtq2208_regulator_buck_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.list_voltage = regulator_list_voltage_linear_range,
	.set_voltage_sel = regulator_set_voltage_sel_regmap,
	.get_voltage_sel = regulator_get_voltage_sel_regmap,
	.set_mode = rtq2208_set_mode,
	.get_mode = rtq2208_get_mode,
	.set_ramp_delay = rtq2208_set_ramp_delay,
	.set_active_discharge = regulator_set_active_discharge_regmap,
	.set_suspend_enable = rtq2208_set_suspend_enable,
	.set_suspend_disable = rtq2208_set_suspend_disable,
	.set_suspend_mode = rtq2208_set_suspend_mode,
};

static const struct regulator_ops rtq2208_regulator_ldo_ops = {
	.enable = regulator_enable_regmap,
	.disable = regulator_disable_regmap,
	.is_enabled = regulator_is_enabled_regmap,
	.set_active_discharge = regulator_set_active_discharge_regmap,
	.set_suspend_enable = rtq2208_set_suspend_enable,
	.set_suspend_disable = rtq2208_set_suspend_disable,
};

static unsigned int rtq2208_of_map_mode(unsigned int mode)
{
	switch (mode) {
	case RTQ2208_AUTO_MODE:
		return REGULATOR_MODE_NORMAL;
	case RTQ2208_FCCM:
		return REGULATOR_MODE_FAST;
	default:
		return REGULATOR_MODE_INVALID;
	}
}

static int rtq2208_init_irq_mask(struct rtq2208_rdev_map *rdev_map, unsigned int *buck_masks)
{
	unsigned char buck_clr_masks[5] = {0x33, 0x33, 0x33, 0x33, 0x33},
		      sts_clr_masks[2] = {0xE7, 0xF7}, sts_masks[2] = {0xE6, 0xF6};
	int ret;

	/* write clear all buck irq once */
	ret = regmap_bulk_write(rdev_map->regmap, RTQ2208_REG_FLT_RECORDBUCK_CB, buck_clr_masks, 5);
	if (ret)
		return dev_err_probe(rdev_map->dev, ret, "Failed to clr buck irqs\n");

	/* write clear general irq once */
	ret = regmap_bulk_write(rdev_map->regmap, RTQ2208_REG_GLOBAL_INT1, sts_clr_masks, 2);
	if (ret)
		return dev_err_probe(rdev_map->dev, ret, "Failed to clr general irqs\n");

	/* unmask buck ov/uv irq */
	ret = regmap_bulk_write(rdev_map->regmap, RTQ2208_REG_FLT_MASKBUCK_CB, buck_masks, 5);
	if (ret)
		return dev_err_probe(rdev_map->dev, ret, "Failed to unmask buck irqs\n");

	/* unmask needed general irq */
	return regmap_bulk_write(rdev_map->regmap, RTQ2208_REG_GLOBAL_INT1_MASK, sts_masks, 2);
}

static irqreturn_t rtq2208_irq_handler(int irqno, void *devid)
{
	unsigned char buck_flags[RTQ2208_BUCK_NUM_IRQ_REGS], sts_flags[RTQ2208_STS_NUM_IRQ_REGS];
	int ret = 0, i, uv_bit, ov_bit;
	struct rtq2208_rdev_map *rdev_map = devid;
	struct regulator_dev *rdev;

	if (!rdev_map)
		return IRQ_NONE;

	/* read irq event */
	ret = regmap_bulk_read(rdev_map->regmap, RTQ2208_REG_FLT_RECORDBUCK_CB,
				buck_flags, ARRAY_SIZE(buck_flags));
	if (ret)
		return IRQ_NONE;

	ret = regmap_bulk_read(rdev_map->regmap, RTQ2208_REG_GLOBAL_INT1,
				sts_flags, ARRAY_SIZE(sts_flags));
	if (ret)
		return IRQ_NONE;

	/* clear irq event */
	ret = regmap_bulk_write(rdev_map->regmap, RTQ2208_REG_FLT_RECORDBUCK_CB,
				buck_flags, ARRAY_SIZE(buck_flags));
	if (ret)
		return IRQ_NONE;

	ret = regmap_bulk_write(rdev_map->regmap, RTQ2208_REG_GLOBAL_INT1,
				sts_flags, ARRAY_SIZE(sts_flags));
	if (ret)
		return IRQ_NONE;

	for (i = 0; i < RTQ2208_LDO_MAX; i++) {
		if (!rdev_map->rdev[i])
			continue;

		rdev = rdev_map->rdev[i];
		/* uv irq */
		uv_bit = (i & 1) ? 4 : 0;
		if (buck_flags[i >> 1] & (1 << uv_bit))
			regulator_notifier_call_chain(rdev,
					REGULATOR_EVENT_UNDER_VOLTAGE, NULL);
		/* ov irq */
		ov_bit = uv_bit + 1;
		if (buck_flags[i >> 1] & (1 << ov_bit))
			regulator_notifier_call_chain(rdev,
					REGULATOR_EVENT_REGULATION_OUT, NULL);

		/* hd irq */
		if (sts_flags[1] & RTQ2208_HD_INT_MASK)
			regulator_notifier_call_chain(rdev,
					REGULATOR_EVENT_OVER_TEMP, NULL);
	}

	return IRQ_HANDLED;
}

#define RTQ2208_REGULATOR_INFO(_name, _base) \
{ \
	.name = #_name, \
	.base = _base, \
}
#define BUCK_RG_BASE(_id)	RTQ2208_REG_BUCK_##_id##_CFG0
#define BUCK_RG_SHIFT(_base, _shift)	(_base + _shift)
#define LDO_RG_BASE(_id)	RTQ2208_REG_LDO##_id##_CFG
#define LDO_RG_SHIFT(_base, _shift)	(_base + _shift)
#define	VSEL_SHIFT(_sel)	(_sel ? 3 : 1)
#define MTP_SEL_MASK(_sel)	RTQ2208_BUCK_EN_NR_MTP_SEL##_sel##_MASK

static const struct linear_range rtq2208_vout_range[] = {
	REGULATOR_LINEAR_RANGE(400000, 0, 180, 5000),
	REGULATOR_LINEAR_RANGE(1310000, 181, 255, 10000),
};

static int rtq2208_of_get_fixed_voltage(struct device *dev,
					struct of_regulator_match *rtq2208_ldo_match, int n_fixed)
{
	struct device_node *np;
	struct of_regulator_match *match;
	struct rtq2208_regulator_desc *rdesc;
	struct regulator_init_data *init_data;
	int ret, i;

	if (!dev->of_node)
		return -ENODEV;

	np = of_get_child_by_name(dev->of_node, "regulators");
	if (!np)
		np = dev->of_node;

	ret = of_regulator_match(dev, np, rtq2208_ldo_match, n_fixed);

	of_node_put(np);

	if (ret < 0)
		return ret;

	for (i = 0; i < n_fixed; i++) {
		match = rtq2208_ldo_match + i;
		init_data = match->init_data;
		rdesc = (struct rtq2208_regulator_desc *)match->driver_data;

		if (!init_data || !rdesc)
			continue;

		if (init_data->constraints.min_uV == init_data->constraints.max_uV)
			rdesc->desc.fixed_uV = init_data->constraints.min_uV;
	}

	return 0;
}

static void rtq2208_init_regulator_desc(struct rtq2208_regulator_desc *rdesc, int mtp_sel,
					int idx, struct of_regulator_match *rtq2208_ldo_match, int *ldo_idx)
{
	struct regulator_desc *desc;
	static const struct {
		char *name;
		int base;
	} regulator_info[] = {
		RTQ2208_REGULATOR_INFO(buck-b, BUCK_RG_BASE(B)),
		RTQ2208_REGULATOR_INFO(buck-c, BUCK_RG_BASE(C)),
		RTQ2208_REGULATOR_INFO(buck-d, BUCK_RG_BASE(D)),
		RTQ2208_REGULATOR_INFO(buck-a, BUCK_RG_BASE(A)),
		RTQ2208_REGULATOR_INFO(buck-f, BUCK_RG_BASE(F)),
		RTQ2208_REGULATOR_INFO(buck-g, BUCK_RG_BASE(G)),
		RTQ2208_REGULATOR_INFO(buck-h, BUCK_RG_BASE(H)),
		RTQ2208_REGULATOR_INFO(buck-e, BUCK_RG_BASE(E)),
		RTQ2208_REGULATOR_INFO(ldo2, LDO_RG_BASE(2)),
		RTQ2208_REGULATOR_INFO(ldo1, LDO_RG_BASE(1)),
	}, *curr_info;

	curr_info = regulator_info + idx;
	desc = &rdesc->desc;
	desc->name = curr_info->name;
	desc->of_match = of_match_ptr(curr_info->name);
	desc->regulators_node = of_match_ptr("regulators");
	desc->id = idx;
	desc->owner = THIS_MODULE;
	desc->type = REGULATOR_VOLTAGE;
	desc->enable_mask = mtp_sel ? MTP_SEL_MASK(1) : MTP_SEL_MASK(0);
	desc->active_discharge_on = RTQ2208_EN_DIS_MASK;
	desc->active_discharge_off = 0;
	desc->active_discharge_mask = RTQ2208_EN_DIS_MASK;

	rdesc->mode_mask = RTQ2208_BUCK_NRMODE_MASK;

	if (idx >= RTQ2208_BUCK_B && idx <= RTQ2208_BUCK_E) {
		/* init buck desc */
		desc->enable_reg = BUCK_RG_SHIFT(curr_info->base, 2);
		desc->ops = &rtq2208_regulator_buck_ops;
		desc->vsel_reg = curr_info->base + VSEL_SHIFT(mtp_sel);
		desc->vsel_mask = RTQ2208_BUCK_NR_MTP_SEL_MASK;
		desc->n_voltages = RTQ2208_VOUT_MAXNUM;
		desc->linear_ranges = rtq2208_vout_range;
		desc->n_linear_ranges = ARRAY_SIZE(rtq2208_vout_range);
		desc->ramp_reg = BUCK_RG_SHIFT(curr_info->base, 5);
		desc->active_discharge_reg = curr_info->base;
		desc->of_map_mode = rtq2208_of_map_mode;

		rdesc->mode_reg = BUCK_RG_SHIFT(curr_info->base, 2);
		rdesc->suspend_config_reg = BUCK_RG_SHIFT(curr_info->base, 4);
		rdesc->suspend_enable_mask = RTQ2208_BUCK_EN_STR_MASK;
		rdesc->suspend_mode_mask = RTQ2208_BUCK_STRMODE_MASK;
	} else {
		/* init ldo desc */
		desc->enable_reg = curr_info->base;
		desc->ops = &rtq2208_regulator_ldo_ops;
		desc->n_voltages = 1;
		desc->active_discharge_reg = LDO_RG_SHIFT(curr_info->base, 2);

		rtq2208_ldo_match[*ldo_idx].name = desc->name;
		rtq2208_ldo_match[*ldo_idx].driver_data = rdesc;
		rtq2208_ldo_match[(*ldo_idx)++].desc = desc;

		rdesc->suspend_config_reg = curr_info->base;
		rdesc->suspend_enable_mask = RTQ2208_LDO_EN_STR_MASK;
	}
}

static int rtq2208_parse_regulator_dt_data(int n_regulator, const unsigned int *regulator_idx_table,
		struct rtq2208_regulator_desc *rdesc[RTQ2208_LDO_MAX], struct device *dev)
{
	struct of_regulator_match rtq2208_ldo_match[2];
	int mtp_sel, ret, i, idx, ldo_idx = 0;

	/* get mtp_sel0 or mtp_sel1 */
	mtp_sel = device_property_read_bool(dev, "richtek,mtp-sel-high");

	for (i = 0; i < n_regulator; i++) {
		idx = regulator_idx_table[i];

		rdesc[i] = devm_kcalloc(dev, 1, sizeof(*rdesc[0]), GFP_KERNEL);
		if (!rdesc[i])
			return -ENOMEM;

		rtq2208_init_regulator_desc(rdesc[i], mtp_sel, idx, rtq2208_ldo_match, &ldo_idx);
	}

	/* init ldo fixed_uV */
	ret = rtq2208_of_get_fixed_voltage(dev, rtq2208_ldo_match, ldo_idx);
	if (ret)
		return dev_err_probe(dev, ret, "Failed to get ldo fixed_uV\n");

	return 0;

}

/** different slave address corresponds different used bucks
 * slave address 0x10: BUCK[BCA FGE]
 * slave address 0x20: BUCK[BC FGHE]
 * slave address 0x40: BUCK[C G]
 */
static int rtq2208_regulator_check(int slave_addr, int *num,
				int *regulator_idx_table, unsigned int *buck_masks)
{
	static bool rtq2208_used_table[3][RTQ2208_LDO_MAX] = {
		/* BUCK[BCA FGE], LDO[12] */
		{1, 1, 0, 1, 1, 1, 0, 1, 1, 1},
		/* BUCK[BC FGHE], LDO[12]*/
		{1, 1, 0, 0, 1, 1, 1, 1, 1, 1},
		/* BUCK[C G], LDO[12] */
		{0, 1, 0, 0, 0, 1, 0, 0, 1, 1},
	};
	int i, idx = ffs(slave_addr >> 4) - 1;
	u8 mask;

	for (i = 0; i < RTQ2208_LDO_MAX; i++) {
		if (!rtq2208_used_table[idx][i])
			continue;

		regulator_idx_table[(*num)++] = i;

		mask = RTQ2208_BUCK_MASK(4 * i, 4 * i + 1);
		buck_masks[i >> 1] &= ~mask;
	}

	return 0;
}

static const struct regmap_config rtq2208_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = 0xEF,
};

static int rtq2208_probe(struct i2c_client *i2c)
{
	struct device *dev = &i2c->dev;
	struct regmap *regmap;
	struct rtq2208_regulator_desc *rdesc[RTQ2208_LDO_MAX];
	struct regulator_dev *rdev;
	struct regulator_config cfg;
	struct rtq2208_rdev_map *rdev_map;
	int i, ret = 0, idx, n_regulator = 0;
	unsigned int regulator_idx_table[RTQ2208_LDO_MAX],
		     buck_masks[RTQ2208_BUCK_NUM_IRQ_REGS] = {0x33, 0x33, 0x33, 0x33, 0x33};

	rdev_map = devm_kzalloc(dev, sizeof(struct rtq2208_rdev_map), GFP_KERNEL);
	if (!rdev_map)
		return -ENOMEM;

	regmap = devm_regmap_init_i2c(i2c, &rtq2208_regmap_config);
	if (IS_ERR(regmap))
		return dev_err_probe(dev, PTR_ERR(regmap), "Failed to allocate regmap\n");

	/* get needed regulator */
	ret = rtq2208_regulator_check(i2c->addr, &n_regulator, regulator_idx_table, buck_masks);
	if (ret)
		return dev_err_probe(dev, ret, "Failed to check used regulators\n");

	rdev_map->regmap = regmap;
	rdev_map->dev = dev;

	cfg.dev = dev;

	/* init regulator desc */
	ret = rtq2208_parse_regulator_dt_data(n_regulator, regulator_idx_table, rdesc, dev);
	if (ret)
		return ret;

	for (i = 0; i < n_regulator; i++) {
		idx = regulator_idx_table[i];

		/* register regulator */
		rdev = devm_regulator_register(dev, &rdesc[i]->desc, &cfg);
		if (IS_ERR(rdev))
			return PTR_ERR(rdev);

		rdev_map->rdev[idx] = rdev;
	}

	/* init interrupt mask */
	ret = rtq2208_init_irq_mask(rdev_map, buck_masks);
	if (ret)
		return ret;

	/* register interrupt */
	return devm_request_threaded_irq(dev, i2c->irq, NULL, rtq2208_irq_handler,
					IRQF_ONESHOT, dev_name(dev), rdev_map);
}

static const struct of_device_id rtq2208_device_tables[] = {
	{ .compatible = "richtek,rtq2208" },
	{}
};
MODULE_DEVICE_TABLE(of, rtq2208_device_tables);

static struct i2c_driver rtq2208_driver = {
	.driver = {
		.name = "rtq2208",
		.of_match_table = rtq2208_device_tables,
	},
	.probe = rtq2208_probe,
};
module_i2c_driver(rtq2208_driver);

MODULE_AUTHOR("Alina Yu <alina_yu@richtek.com>");
MODULE_DESCRIPTION("Richtek RTQ2208 Regulator Driver");
MODULE_LICENSE("GPL");