// SPDX-License-Identifier: GPL-2.0+
//
// Regulator driver for DA9055 PMIC
//
// Copyright(c) 2012 Dialog Semiconductor Ltd.
//
// Author: David Dajun Chen <dchen@diasemi.com>

#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/of.h>
#include <linux/regulator/of_regulator.h>

#include <linux/mfd/da9055/core.h>
#include <linux/mfd/da9055/reg.h>
#include <linux/mfd/da9055/pdata.h>

#define DA9055_MIN_UA           0
#define DA9055_MAX_UA           3

#define DA9055_LDO_MODE_SYNC    0
#define DA9055_LDO_MODE_SLEEP   1

#define DA9055_BUCK_MODE_SLEEP  1
#define DA9055_BUCK_MODE_SYNC   2
#define DA9055_BUCK_MODE_AUTO   3

/* DA9055 REGULATOR IDs */
#define DA9055_ID_BUCK1 0
#define DA9055_ID_BUCK2 1
#define DA9055_ID_LDO1          2
#define DA9055_ID_LDO2          3
#define DA9055_ID_LDO3          4
#define DA9055_ID_LDO4          5
#define DA9055_ID_LDO5          6
#define DA9055_ID_LDO6          7

/* DA9055 BUCK current limit */
static const unsigned int da9055_current_limits[] = {
        500000, 600000, 700000, 800000
};

struct da9055_conf_reg {
        int reg;
        int sel_mask;
        int en_mask;
};

struct da9055_volt_reg {
        int reg_a;
        int reg_b;
        int sl_shift;
        int v_mask;
};

struct da9055_mode_reg {
        int reg;
        int mask;
        int shift;
};

struct da9055_regulator_info {
        struct regulator_desc reg_desc;
        struct da9055_conf_reg conf;
        struct da9055_volt_reg volt;
        struct da9055_mode_reg mode;
};

struct da9055_regulator {
        struct da9055 *da9055;
        const struct da9055_regulator_info *info;
        struct regulator_dev *rdev;
        enum gpio_select reg_rselect;
};

static unsigned int da9055_buck_get_mode(struct regulator_dev *rdev)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;
        int ret, mode = 0;

        ret = da9055_reg_read(regulator->da9055, info->mode.reg);
        if (ret < 0)
                return ret;

        switch ((ret & info->mode.mask) >> info->mode.shift) {
        case DA9055_BUCK_MODE_SYNC:
                mode = REGULATOR_MODE_FAST;
                break;
        case DA9055_BUCK_MODE_AUTO:
                mode = REGULATOR_MODE_NORMAL;
                break;
        case DA9055_BUCK_MODE_SLEEP:
                mode = REGULATOR_MODE_STANDBY;
                break;
        }

        return mode;
}

static int da9055_buck_set_mode(struct regulator_dev *rdev,
                                        unsigned int mode)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;
        int val = 0;

        switch (mode) {
        case REGULATOR_MODE_FAST:
                val = DA9055_BUCK_MODE_SYNC << info->mode.shift;
                break;
        case REGULATOR_MODE_NORMAL:
                val = DA9055_BUCK_MODE_AUTO << info->mode.shift;
                break;
        case REGULATOR_MODE_STANDBY:
                val = DA9055_BUCK_MODE_SLEEP << info->mode.shift;
                break;
        }

        return da9055_reg_update(regulator->da9055, info->mode.reg,
                                 info->mode.mask, val);
}

static unsigned int da9055_ldo_get_mode(struct regulator_dev *rdev)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;
        int ret;

        ret = da9055_reg_read(regulator->da9055, info->volt.reg_b);
        if (ret < 0)
                return ret;

        if (ret >> info->volt.sl_shift)
                return REGULATOR_MODE_STANDBY;
        else
                return REGULATOR_MODE_NORMAL;
}

static int da9055_ldo_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;
        struct da9055_volt_reg volt = info->volt;
        int val = 0;

        switch (mode) {
        case REGULATOR_MODE_NORMAL:
        case REGULATOR_MODE_FAST:
                val = DA9055_LDO_MODE_SYNC;
                break;
        case REGULATOR_MODE_STANDBY:
                val = DA9055_LDO_MODE_SLEEP;
                break;
        }

        return da9055_reg_update(regulator->da9055, volt.reg_b,
                                 1 << volt.sl_shift,
                                 val << volt.sl_shift);
}

static int da9055_regulator_get_voltage_sel(struct regulator_dev *rdev)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;
        struct da9055_volt_reg volt = info->volt;
        int ret, sel;

        /*
         * There are two voltage register set A & B for voltage ramping but
         * either one of then can be active therefore we first determine
         * the active register set.
         */
        ret = da9055_reg_read(regulator->da9055, info->conf.reg);
        if (ret < 0)
                return ret;

        ret &= info->conf.sel_mask;

        /* Get the voltage for the active register set A/B */
        if (ret == DA9055_REGUALTOR_SET_A)
                ret = da9055_reg_read(regulator->da9055, volt.reg_a);
        else
                ret = da9055_reg_read(regulator->da9055, volt.reg_b);

        if (ret < 0)
                return ret;

        sel = (ret & volt.v_mask);
        return sel;
}

static int da9055_regulator_set_voltage_sel(struct regulator_dev *rdev,
                                            unsigned int selector)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;
        int ret;

        /*
         * Regulator register set A/B is not selected through GPIO therefore
         * we use default register set A for voltage ramping.
         */
        if (regulator->reg_rselect == NO_GPIO) {
                /* Select register set A */
                ret = da9055_reg_update(regulator->da9055, info->conf.reg,
                                        info->conf.sel_mask, DA9055_SEL_REG_A);
                if (ret < 0)
                        return ret;

                /* Set the voltage */
                return da9055_reg_update(regulator->da9055, info->volt.reg_a,
                                         info->volt.v_mask, selector);
        }

        /*
         * Here regulator register set A/B is selected through GPIO.
         * Therefore we first determine the selected register set A/B and
         * then set the desired voltage for that register set A/B.
         */
        ret = da9055_reg_read(regulator->da9055, info->conf.reg);
        if (ret < 0)
                return ret;

        ret &= info->conf.sel_mask;

        /* Set the voltage */
        if (ret == DA9055_REGUALTOR_SET_A)
                return da9055_reg_update(regulator->da9055, info->volt.reg_a,
                                         info->volt.v_mask, selector);
        else
                return da9055_reg_update(regulator->da9055, info->volt.reg_b,
                                         info->volt.v_mask, selector);
}

static int da9055_regulator_set_suspend_voltage(struct regulator_dev *rdev,
                                                int uV)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;
        int ret;

        /* Select register set B for suspend voltage ramping. */
        if (regulator->reg_rselect == NO_GPIO) {
                ret = da9055_reg_update(regulator->da9055, info->conf.reg,
                                        info->conf.sel_mask, DA9055_SEL_REG_B);
                if (ret < 0)
                        return ret;
        }

        ret = regulator_map_voltage_linear(rdev, uV, uV);
        if (ret < 0)
                return ret;

        return da9055_reg_update(regulator->da9055, info->volt.reg_b,
                                 info->volt.v_mask, ret);
}

static int da9055_suspend_enable(struct regulator_dev *rdev)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;

        /* Select register set B for voltage ramping. */
        if (regulator->reg_rselect == NO_GPIO)
                return da9055_reg_update(regulator->da9055, info->conf.reg,
                                        info->conf.sel_mask, DA9055_SEL_REG_B);
        else
                return 0;
}

static int da9055_suspend_disable(struct regulator_dev *rdev)
{
        struct da9055_regulator *regulator = rdev_get_drvdata(rdev);
        const struct da9055_regulator_info *info = regulator->info;

        /* Diselect register set B. */
        if (regulator->reg_rselect == NO_GPIO)
                return da9055_reg_update(regulator->da9055, info->conf.reg,
                                        info->conf.sel_mask, DA9055_SEL_REG_A);
        else
                return 0;
}

static const struct regulator_ops da9055_buck_ops = {
        .get_mode = da9055_buck_get_mode,
        .set_mode = da9055_buck_set_mode,

        .get_current_limit = regulator_get_current_limit_regmap,
        .set_current_limit = regulator_set_current_limit_regmap,

        .get_voltage_sel = da9055_regulator_get_voltage_sel,
        .set_voltage_sel = da9055_regulator_set_voltage_sel,
        .list_voltage = regulator_list_voltage_linear,
        .map_voltage = regulator_map_voltage_linear,
        .is_enabled = regulator_is_enabled_regmap,
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,

        .set_suspend_voltage = da9055_regulator_set_suspend_voltage,
        .set_suspend_enable = da9055_suspend_enable,
        .set_suspend_disable = da9055_suspend_disable,
        .set_suspend_mode = da9055_buck_set_mode,
};

static const struct regulator_ops da9055_ldo_ops = {
        .get_mode = da9055_ldo_get_mode,
        .set_mode = da9055_ldo_set_mode,

        .get_voltage_sel = da9055_regulator_get_voltage_sel,
        .set_voltage_sel = da9055_regulator_set_voltage_sel,
        .list_voltage = regulator_list_voltage_linear,
        .map_voltage = regulator_map_voltage_linear,
        .is_enabled = regulator_is_enabled_regmap,
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,

        .set_suspend_voltage = da9055_regulator_set_suspend_voltage,
        .set_suspend_enable = da9055_suspend_enable,
        .set_suspend_disable = da9055_suspend_disable,
        .set_suspend_mode = da9055_ldo_set_mode,

};

#define DA9055_LDO(_id, step, min, max, vbits, voffset) \
{\
        .reg_desc = {\
                .name = #_id,\
                .of_match = of_match_ptr(#_id),\
                .regulators_node = of_match_ptr("regulators"),\
                .ops = &da9055_ldo_ops,\
                .type = REGULATOR_VOLTAGE,\
                .id = DA9055_ID_##_id,\
                .n_voltages = (max - min) / step + 1 + (voffset), \
                .enable_reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
                .enable_mask = 1, \
                .min_uV = (min) * 1000,\
                .uV_step = (step) * 1000,\
                .linear_min_sel = (voffset),\
                .owner = THIS_MODULE,\
        },\
        .conf = {\
                .reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
                .sel_mask = (1 << 4),\
                .en_mask = 1,\
        },\
        .volt = {\
                .reg_a = DA9055_REG_VBCORE_A + DA9055_ID_##_id, \
                .reg_b = DA9055_REG_VBCORE_B + DA9055_ID_##_id, \
                .sl_shift = 7,\
                .v_mask = (1 << (vbits)) - 1,\
        },\
}

#define DA9055_BUCK(_id, step, min, max, vbits, voffset, mbits, sbits) \
{\
        .reg_desc = {\
                .name = #_id,\
                .of_match = of_match_ptr(#_id),\
                .regulators_node = of_match_ptr("regulators"),\
                .ops = &da9055_buck_ops,\
                .type = REGULATOR_VOLTAGE,\
                .id = DA9055_ID_##_id,\
                .n_voltages = (max - min) / step + 1 + (voffset), \
                .enable_reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
                .enable_mask = 1,\
                .min_uV = (min) * 1000,\
                .uV_step = (step) * 1000,\
                .linear_min_sel = (voffset),\
                .owner = THIS_MODULE,\
                .curr_table = da9055_current_limits,\
                .n_current_limits = ARRAY_SIZE(da9055_current_limits),\
                .csel_reg = DA9055_REG_BUCK_LIM,\
                .csel_mask = (mbits),\
        },\
        .conf = {\
                .reg = DA9055_REG_BCORE_CONT + DA9055_ID_##_id, \
                .sel_mask = (1 << 4),\
                .en_mask = 1,\
        },\
        .volt = {\
                .reg_a = DA9055_REG_VBCORE_A + DA9055_ID_##_id, \
                .reg_b = DA9055_REG_VBCORE_B + DA9055_ID_##_id, \
                .sl_shift = 7,\
                .v_mask = (1 << (vbits)) - 1,\
        },\
        .mode = {\
                .reg = DA9055_REG_BCORE_MODE,\
                .mask = (mbits),\
                .shift = (sbits),\
        },\
}

static const struct da9055_regulator_info da9055_regulator_info[] = {
        DA9055_BUCK(BUCK1, 25, 725, 2075, 6, 9, 0xc, 2),
        DA9055_BUCK(BUCK2, 25, 925, 2500, 6, 0, 3, 0),
        DA9055_LDO(LDO1, 50, 900, 3300, 6, 2),
        DA9055_LDO(LDO2, 50, 900, 3300, 6, 3),
        DA9055_LDO(LDO3, 50, 900, 3300, 6, 2),
        DA9055_LDO(LDO4, 50, 900, 3300, 6, 2),
        DA9055_LDO(LDO5, 50, 900, 2750, 6, 2),
        DA9055_LDO(LDO6, 20, 900, 3300, 7, 0),
};

/*
 * Configures regulator to be controlled either through GPIO 1 or 2.
 * GPIO can control regulator state and/or select the regulator register
 * set A/B for voltage ramping.
 */
static int da9055_gpio_init(struct device *dev,
                            struct da9055_regulator *regulator,
                            struct regulator_config *config,
                            struct da9055_pdata *pdata, int id)
{
        const struct da9055_regulator_info *info = regulator->info;
        struct gpio_desc *ren;
        struct gpio_desc *ena;
        struct gpio_desc *rsel;
        int ret = 0;

        /* Look for "regulator-enable-gpios" GPIOs in the regulator node */
        ren = devm_gpiod_get_optional(dev, "regulator-enable", GPIOD_IN);
        if (IS_ERR(ren))
                return PTR_ERR(ren);

        if (ren) {
                /* This GPIO is not optional at this point */
                ena = devm_gpiod_get(dev, "enable", GPIOD_OUT_HIGH);
                if (IS_ERR(ena))
                        return PTR_ERR(ena);

                config->ena_gpiod = ena;

                /*
                 * GPI pin is muxed with regulator to control the
                 * regulator state.
                 */
                gpiod_set_consumer_name(ren, "DA9055 ren GPI");

                /*
                 * Let the regulator know that its state is controlled
                 * through GPI.
                 */
                ret = da9055_reg_update(regulator->da9055, info->conf.reg,
                                        DA9055_E_GPI_MASK,
                                        pdata->reg_ren[id]
                                        << DA9055_E_GPI_SHIFT);
                if (ret < 0)
                        return ret;
        }

        /* Look for "regulator-select-gpios" GPIOs in the regulator node */
        rsel = devm_gpiod_get_optional(dev, "regulator-select", GPIOD_IN);
        if (IS_ERR(rsel))
                return PTR_ERR(rsel);

        if (rsel) {
                regulator->reg_rselect = pdata->reg_rsel[id];

                /*
                 * GPI pin is muxed with regulator to select the
                 * regulator register set A/B for voltage ramping.
                 */
                gpiod_set_consumer_name(rsel, "DA9055 rsel GPI");

                /*
                 * Let the regulator know that its register set A/B
                 * will be selected through GPI for voltage ramping.
                 */
                ret = da9055_reg_update(regulator->da9055, info->conf.reg,
                                        DA9055_V_GPI_MASK,
                                        pdata->reg_rsel[id]
                                        << DA9055_V_GPI_SHIFT);
        }

        return ret;
}

static irqreturn_t da9055_ldo5_6_oc_irq(int irq, void *data)
{
        struct da9055_regulator *regulator = data;

        regulator_notifier_call_chain(regulator->rdev,
                                      REGULATOR_EVENT_OVER_CURRENT, NULL);

        return IRQ_HANDLED;
}

static inline const struct da9055_regulator_info *find_regulator_info(int id)
{
        const struct da9055_regulator_info *info;
        int i;

        for (i = 0; i < ARRAY_SIZE(da9055_regulator_info); i++) {
                info = &da9055_regulator_info[i];
                if (info->reg_desc.id == id)
                        return info;
        }

        return NULL;
}

static int da9055_regulator_probe(struct platform_device *pdev)
{
        struct regulator_config config = { };
        struct da9055_regulator *regulator;
        struct da9055 *da9055 = dev_get_drvdata(pdev->dev.parent);
        struct da9055_pdata *pdata = dev_get_platdata(da9055->dev);
        int ret, irq;

        regulator = devm_kzalloc(&pdev->dev, sizeof(struct da9055_regulator),
                                 GFP_KERNEL);
        if (!regulator)
                return -ENOMEM;

        regulator->info = find_regulator_info(pdev->id);
        if (regulator->info == NULL) {
                dev_err(&pdev->dev, "invalid regulator ID specified\n");
                return -EINVAL;
        }

        regulator->da9055 = da9055;
        config.dev = da9055->dev;
        config.driver_data = regulator;
        config.regmap = da9055->regmap;

        if (pdata)
                config.init_data = pdata->regulators[pdev->id];

        ret = da9055_gpio_init(&pdev->dev, regulator, &config, pdata, pdev->id);
        if (ret < 0)
                return ret;

        regulator->rdev = devm_regulator_register(&pdev->dev,
                                                  &regulator->info->reg_desc,
                                                  &config);
        if (IS_ERR(regulator->rdev)) {
                dev_err(&pdev->dev, "Failed to register regulator %s\n",
                        regulator->info->reg_desc.name);
                return PTR_ERR(regulator->rdev);
        }

        /* Only LDO 5 and 6 has got the over current interrupt */
        if (pdev->id == DA9055_ID_LDO5 || pdev->id ==  DA9055_ID_LDO6) {
                irq = platform_get_irq_byname(pdev, "REGULATOR");
                if (irq < 0)
                        return irq;

                ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
                                                da9055_ldo5_6_oc_irq,
                                                IRQF_TRIGGER_HIGH |
                                                IRQF_ONESHOT |
                                                IRQF_PROBE_SHARED,
                                                pdev->name, regulator);
                if (ret != 0) {
                        if (ret != -EBUSY) {
                                dev_err(&pdev->dev,
                                "Failed to request Regulator IRQ %d: %d\n",
                                irq, ret);
                                return ret;
                        }
                }
        }

        platform_set_drvdata(pdev, regulator);

        return 0;
}

static struct platform_driver da9055_regulator_driver = {
        .probe = da9055_regulator_probe,
        .driver = {
                .name = "da9055-regulator",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
};

static int __init da9055_regulator_init(void)
{
        return platform_driver_register(&da9055_regulator_driver);
}
subsys_initcall(da9055_regulator_init);

static void __exit da9055_regulator_exit(void)
{
        platform_driver_unregister(&da9055_regulator_driver);
}
module_exit(da9055_regulator_exit);

MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
MODULE_DESCRIPTION("Power Regulator driver for Dialog DA9055 PMIC");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da9055-regulator");