root/drivers/regulator/rt8092.c
// SPDX-License-Identifier: GPL-2.0+
//
// Copyright (c) 2025 Richtek Technology Corp.
//
// Author: ChiYuan Huang <cy_huang@richtek.com>

#include <linux/bitfield.h>
#include <linux/bits.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>

#define RT8092_REG_MNTRPT       0x00
#define RT8092_REG_VOUTH        0x10
#define RT8092_REG_VOUTL        0x11
#define RT8092_REG_PWMMODE      0x14
#define RT8092_REG_EVENT        0x18
#define RT8092_REG_VBANKH       0x1C
#define RT8092_REG_VBANKL       0x1D
#define RT8092_REG_VBOUND       0x1E

#define RT8092_TSDEVT_MASK      BIT(7)
#define RT8092_PGEVT_MASK       BIT(0)
#define RT8092_VSEL_MASK        GENMASK(6, 0)
#define RT8092_VOUTEN_MASK      BIT(7)
#define RT8092_FPWML_MASK       BIT(7)
#define RT8092_FPWMH_MASK       BIT(6)
#define RT8092_OCPEVT_MASK      BIT(7)
#define RT8092_SCPEVT_MASK      BIT(4)
#define RT8092_VINUVEVT_MASK    BIT(1)
#define RT8092_VBANK_MASK       GENMASK(1, 0)

#define RT8092_MODE_AUTO        0
#define RT8092_MODE_FPWM        1
#define RT8092_VOUT_BASEUV      303125
#define RT8092_VOUT_STEPUV      3125
#define RT8092_VOUT_MINSEL      15
#define RT8092_NUM_VOLTS        128
#define RT8092_INITSS_US        400

static int rt8092_get_vbank_index(struct regmap *regmap, bool vsel_high, unsigned int *vbank_idx)
{
        unsigned int vbank_reg = vsel_high ? RT8092_REG_VBANKH : RT8092_REG_VBANKL;
        unsigned int index;
        int ret;

        ret = regmap_read(regmap, vbank_reg, &index);
        if (ret)
                return ret;

        *vbank_idx = FIELD_GET(RT8092_VBANK_MASK, index);
        return 0;
}

static int rt8092_set_operating_mode(struct regulator_dev *rdev, unsigned int mode)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mode_mask, mode_val;

        mode_mask = desc->vsel_reg == RT8092_REG_VOUTH ? RT8092_FPWMH_MASK : RT8092_FPWML_MASK;

        switch (mode) {
        case REGULATOR_MODE_FAST:
                mode_val = mode_mask;
                break;
        case REGULATOR_MODE_NORMAL:
                mode_val = 0;
                break;
        default:
                return -EINVAL;
        }

        return regmap_update_bits(regmap, RT8092_REG_PWMMODE, mode_mask, mode_val);
}

static unsigned int rt8092_get_operating_mode(struct regulator_dev *rdev)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mode_mask, mode_val;
        int ret;

        mode_mask = desc->vsel_reg == RT8092_REG_VOUTH ? RT8092_FPWMH_MASK : RT8092_FPWML_MASK;

        ret = regmap_read(regmap, RT8092_REG_PWMMODE, &mode_val);
        if (ret)
                return REGULATOR_MODE_INVALID;

        return mode_val & mode_mask ? REGULATOR_MODE_FAST : REGULATOR_MODE_NORMAL;
}

static int rt8092_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
{
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mntrpt, evtrpt, events = 0;
        int ret;

        ret = regmap_read(regmap, RT8092_REG_MNTRPT, &mntrpt);
        if (ret)
                return ret;

        ret = regmap_read(regmap, RT8092_REG_EVENT, &evtrpt);
        if (ret)
                return ret;

        if (!(mntrpt & RT8092_PGEVT_MASK) || evtrpt & RT8092_VINUVEVT_MASK)
                events |= REGULATOR_ERROR_UNDER_VOLTAGE;

        if (mntrpt & RT8092_TSDEVT_MASK)
                events |= REGULATOR_ERROR_OVER_TEMP;

        if (evtrpt & RT8092_OCPEVT_MASK)
                events |= REGULATOR_ERROR_OVER_CURRENT;

        if (evtrpt & RT8092_SCPEVT_MASK)
                events |= REGULATOR_ERROR_FAIL;

        *flags = events;
        return 0;
}


static int rt8092_set_suspend_voltage(struct regulator_dev *rdev, int uV)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int vsel_reg, vsel_val, vbank_idx;
        bool vsel_high;
        int ret;

        vsel_reg = desc->vsel_reg == RT8092_REG_VOUTH ? RT8092_REG_VOUTL : RT8092_REG_VOUTH;
        vsel_high = desc->vsel_reg == RT8092_REG_VOUTH;

        ret = rt8092_get_vbank_index(regmap, vsel_high, &vbank_idx);
        if (ret)
                return ret;

        /* VOUT  = (BASEUV + STEPUV * VSEL) * 2^vbank_idx */
        uV >>= vbank_idx;
        if (uV < RT8092_VOUT_BASEUV)
                return -EINVAL;

        vsel_val = (uV - RT8092_VOUT_BASEUV) / RT8092_VOUT_STEPUV;
        if (vsel_val < RT8092_VOUT_MINSEL || vsel_val >= RT8092_NUM_VOLTS)
                return -EINVAL;

        return regmap_update_bits(regmap, vsel_reg, RT8092_VSEL_MASK, vsel_val);
}

static int rt8092_set_suspend_enable(struct regulator_dev *rdev)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int enable_reg;

        enable_reg = desc->vsel_reg == RT8092_REG_VOUTH ? RT8092_REG_VOUTL : RT8092_REG_VOUTH;
        return regmap_set_bits(regmap, enable_reg, RT8092_VOUTEN_MASK);
}

static int rt8092_set_suspend_disable(struct regulator_dev *rdev)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int enable_reg;

        enable_reg = desc->vsel_reg == RT8092_REG_VOUTH ? RT8092_REG_VOUTL : RT8092_REG_VOUTH;
        return regmap_clear_bits(regmap, enable_reg, RT8092_VOUTEN_MASK);
}

static int rt8092_set_suspend_mode(struct regulator_dev *rdev, unsigned int mode)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mode_mask, mode_val;

        mode_mask = desc->vsel_reg == RT8092_REG_VOUTH ? RT8092_FPWML_MASK : RT8092_FPWMH_MASK;

        switch (mode) {
        case REGULATOR_MODE_FAST:
                mode_val = mode_mask;
                break;
        case REGULATOR_MODE_NORMAL:
                mode_val = 0;
                break;
        default:
                return -EINVAL;
        }

        return regmap_update_bits(regmap, RT8092_REG_PWMMODE, mode_mask, mode_val);
}

static const struct regulator_ops rt8092_regulator_ops = {
        .list_voltage = regulator_list_voltage_linear,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .set_mode = rt8092_set_operating_mode,
        .get_mode = rt8092_get_operating_mode,
        .get_error_flags = rt8092_get_error_flags,
        .set_suspend_voltage = rt8092_set_suspend_voltage,
        .set_suspend_enable = rt8092_set_suspend_enable,
        .set_suspend_disable = rt8092_set_suspend_disable,
        .set_suspend_mode = rt8092_set_suspend_mode,
};

static unsigned int rt8092_of_map_mode(unsigned int mode)
{
        switch (mode) {
        case RT8092_MODE_AUTO:
                return REGULATOR_MODE_NORMAL;
        case RT8092_MODE_FPWM:
                return REGULATOR_MODE_FAST;
        default:
                return REGULATOR_MODE_INVALID;
        }
}

static const struct regmap_config rt8092_regmap_cfg = {
        .name = "rt8092",
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = RT8092_REG_VBOUND,
};

static int rt8092_probe(struct i2c_client *i2c)
{
        unsigned int vbank_idx, min_uV, step_uV;
        struct regulator_config cfg = {};
        struct device *dev = &i2c->dev;
        struct regulator_desc *desc;
        struct regulator_dev *rdev;
        struct gpio_desc *enable;
        struct regmap *regmap;
        bool vsel_high;
        int ret;

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

        enable = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
        if (IS_ERR(enable))
                return dev_err_probe(dev, PTR_ERR(enable), "Failed get 'enable' gpio\n");

        regmap = devm_regmap_init_i2c(i2c, &rt8092_regmap_cfg);
        if (IS_ERR(regmap))
                return dev_err_probe(dev, PTR_ERR(regmap), "Failed to init regmap\n");

        vsel_high = device_property_read_bool(dev, "richtek,vsel-active-high");

        ret = rt8092_get_vbank_index(regmap, vsel_high, &vbank_idx);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to get VOUT bank index\n");

        /*
         * step VOUT = STEP_UV * 2^vbank_idx
         * min VOUT  = (BASEUV + STEPUV * VMIN_SEL) * 2^vbank_idx
         */
        step_uV = RT8092_VOUT_STEPUV << vbank_idx;
        min_uV = (RT8092_VOUT_BASEUV + RT8092_VOUT_STEPUV * RT8092_VOUT_MINSEL) << vbank_idx;

        desc->name = "rt8092";
        desc->owner = THIS_MODULE;
        desc->type = REGULATOR_VOLTAGE;
        desc->ops = &rt8092_regulator_ops;
        desc->n_voltages = RT8092_NUM_VOLTS;
        desc->min_uV = min_uV;
        desc->uV_step = step_uV;
        desc->linear_min_sel = RT8092_VOUT_MINSEL;
        desc->enable_reg = desc->vsel_reg = vsel_high ? RT8092_REG_VOUTH : RT8092_REG_VOUTL;
        desc->vsel_mask = RT8092_VSEL_MASK;
        desc->enable_mask = RT8092_VOUTEN_MASK;
        desc->enable_time = RT8092_INITSS_US;
        desc->of_map_mode = rt8092_of_map_mode;

        cfg.dev = dev;
        cfg.of_node = dev_of_node(dev);
        cfg.init_data = of_get_regulator_init_data(dev, dev_of_node(dev), desc);

        rdev = devm_regulator_register(dev, desc, &cfg);
        if (IS_ERR(rdev))
                return dev_err_probe(dev, PTR_ERR(rdev), "Failed to register regulator\n");

        return 0;
}

static const struct of_device_id rt8092_device_tables[] = {
        { .compatible = "richtek,rt8092" },
        {}
};
MODULE_DEVICE_TABLE(of, rt8092_device_tables);

static struct i2c_driver rt8092_driver = {
        .driver = {
                .name = "rt8092",
                .of_match_table = rt8092_device_tables,
        },
        .probe = rt8092_probe,
};
module_i2c_driver(rt8092_driver);

MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
MODULE_DESCRIPTION("Richtek RT8092 Regulator Driver");
MODULE_LICENSE("GPL");