root/drivers/regulator/rt5739.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Device driver for RT5739 regulator
 *
 * Copyright (C) 2023 Richtek Technology Corp.
 *
 * Author: ChiYuan Huang <cy_huang@richtek.com>
 */

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

#define RT5739_AUTO_MODE        0
#define RT5739_FPWM_MODE        1

#define RT5739_REG_NSEL0        0x00
#define RT5739_REG_NSEL1        0x01
#define RT5739_REG_CNTL1        0x02
#define RT5739_REG_ID1          0x03
#define RT5739_REG_ID2          0x04
#define RT5739_REG_MON          0x05
#define RT5739_REG_CNTL2        0x06
#define RT5739_REG_CNTL4        0x08

#define RT5739_VSEL_MASK        GENMASK(7, 0)
#define RT5739_MODEVSEL1_MASK   BIT(1)
#define RT5739_MODEVSEL0_MASK   BIT(0)
#define RT5739_VID_MASK         GENMASK(7, 5)
#define RT5739_DID_MASK         GENMASK(3, 0)
#define RT5739_ACTD_MASK        BIT(7)
#define RT5739_ENVSEL1_MASK     BIT(1)
#define RT5739_ENVSEL0_MASK     BIT(0)

#define RT5733_CHIPDIE_ID       0x1
#define RT5733_VOLT_MINUV       270000
#define RT5733_VOLT_MAXUV       1401250
#define RT5733_VOLT_STPUV       6250
#define RT5733_N_VOLTS          182

#define RT5739_VOLT_MINUV       300000
#define RT5739_VOLT_MAXUV       1300000
#define RT5739_VOLT_STPUV       5000
#define RT5739_N_VOLTS          201
#define RT5739_I2CRDY_TIMEUS    1000

static int rt5739_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mask, val;

        if (desc->vsel_reg == RT5739_REG_NSEL0)
                mask = RT5739_MODEVSEL0_MASK;
        else
                mask = RT5739_MODEVSEL1_MASK;

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

        return regmap_update_bits(regmap, RT5739_REG_CNTL1, mask, val);
}

static unsigned int rt5739_get_mode(struct regulator_dev *rdev)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mask, val;
        int ret;

        if (desc->vsel_reg == RT5739_REG_NSEL0)
                mask = RT5739_MODEVSEL0_MASK;
        else
                mask = RT5739_MODEVSEL1_MASK;

        ret = regmap_read(regmap, RT5739_REG_CNTL1, &val);
        if (ret)
                return REGULATOR_MODE_INVALID;

        if (val & mask)
                return REGULATOR_MODE_FAST;

        return REGULATOR_MODE_NORMAL;
}

static int rt5739_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 reg, vsel;
        int max_uV;

        max_uV = desc->min_uV + desc->uV_step * (desc->n_voltages - 1);

        if (uV < desc->min_uV || uV > max_uV)
                return -EINVAL;

        if (desc->vsel_reg == RT5739_REG_NSEL0)
                reg = RT5739_REG_NSEL1;
        else
                reg = RT5739_REG_NSEL0;

        vsel = (uV - desc->min_uV) / desc->uV_step;
        return regmap_write(regmap, reg, vsel);
}

static int rt5739_set_suspend_enable(struct regulator_dev *rdev)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mask;

        if (desc->vsel_reg == RT5739_REG_NSEL0)
                mask = RT5739_ENVSEL1_MASK;
        else
                mask = RT5739_ENVSEL0_MASK;

        return regmap_update_bits(regmap, desc->enable_reg, mask, mask);
}

static int rt5739_set_suspend_disable(struct regulator_dev *rdev)
{
        const struct regulator_desc *desc = rdev->desc;
        struct regmap *regmap = rdev_get_regmap(rdev);
        unsigned int mask;

        if (desc->vsel_reg == RT5739_REG_NSEL0)
                mask = RT5739_ENVSEL1_MASK;
        else
                mask = RT5739_ENVSEL0_MASK;

        return regmap_update_bits(regmap, desc->enable_reg, mask, 0);
}

static int rt5739_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 mask, val;

        if (desc->vsel_reg == RT5739_REG_NSEL0)
                mask = RT5739_MODEVSEL1_MASK;
        else
                mask = RT5739_MODEVSEL0_MASK;

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

        return regmap_update_bits(regmap, RT5739_REG_CNTL1, mask, val);
}

static const struct regulator_ops rt5739_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_active_discharge = regulator_set_active_discharge_regmap,
        .set_mode = rt5739_set_mode,
        .get_mode = rt5739_get_mode,
        .set_suspend_voltage = rt5739_set_suspend_voltage,
        .set_suspend_enable = rt5739_set_suspend_enable,
        .set_suspend_disable = rt5739_set_suspend_disable,
        .set_suspend_mode = rt5739_set_suspend_mode,
};

static unsigned int rt5739_of_map_mode(unsigned int mode)
{
        switch (mode) {
        case RT5739_AUTO_MODE:
                return REGULATOR_MODE_NORMAL;
        case RT5739_FPWM_MODE:
                return REGULATOR_MODE_FAST;
        default:
                return REGULATOR_MODE_INVALID;
        }
}

static void rt5739_init_regulator_desc(struct regulator_desc *desc,
                                       bool vsel_active_high, u8 did)
{
        /* Fixed */
        desc->name = "rt5739-regulator";
        desc->owner = THIS_MODULE;
        desc->ops = &rt5739_regulator_ops;
        desc->vsel_mask = RT5739_VSEL_MASK;
        desc->enable_reg = RT5739_REG_CNTL2;
        desc->active_discharge_reg = RT5739_REG_CNTL1;
        desc->active_discharge_mask = RT5739_ACTD_MASK;
        desc->active_discharge_on = RT5739_ACTD_MASK;
        desc->of_map_mode = rt5739_of_map_mode;

        /* Assigned by vsel level */
        if (vsel_active_high) {
                desc->vsel_reg = RT5739_REG_NSEL1;
                desc->enable_mask = RT5739_ENVSEL1_MASK;
        } else {
                desc->vsel_reg = RT5739_REG_NSEL0;
                desc->enable_mask = RT5739_ENVSEL0_MASK;
        }

        /* Assigned by CHIPDIE ID */
        switch (did) {
        case RT5733_CHIPDIE_ID:
                desc->n_voltages = RT5733_N_VOLTS;
                desc->min_uV = RT5733_VOLT_MINUV;
                desc->uV_step = RT5733_VOLT_STPUV;
                break;
        default:
                desc->n_voltages = RT5739_N_VOLTS;
                desc->min_uV = RT5739_VOLT_MINUV;
                desc->uV_step = RT5739_VOLT_STPUV;
                break;
        }
}

static bool rt5739_volatile_reg(struct device *dev, unsigned int reg)
{
        return reg == RT5739_REG_MON;
}

static const struct regmap_config rt5739_regmap_config = {
        .name = "rt5739",
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = RT5739_REG_CNTL4,
        .cache_type = REGCACHE_MAPLE,
        .volatile_reg = rt5739_volatile_reg,
};

static int rt5739_probe(struct i2c_client *i2c)
{
        struct device *dev = &i2c->dev;
        struct regulator_desc *desc;
        struct regmap *regmap;
        struct gpio_desc *enable_gpio;
        struct regulator_config cfg = {};
        struct regulator_dev *rdev;
        bool vsel_acth;
        unsigned int vid;
        int ret;

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

        enable_gpio = devm_gpiod_get_optional(dev, "enable", GPIOD_OUT_HIGH);
        if (IS_ERR(enable_gpio))
                return dev_err_probe(dev, PTR_ERR(enable_gpio), "Failed to get 'enable' gpio\n");
        else if (enable_gpio)
                usleep_range(RT5739_I2CRDY_TIMEUS, RT5739_I2CRDY_TIMEUS + 1000);

        regmap = devm_regmap_init_i2c(i2c, &rt5739_regmap_config);
        if (IS_ERR(regmap))
                return dev_err_probe(dev, PTR_ERR(regmap), "Failed to init regmap\n");

        ret = regmap_read(regmap, RT5739_REG_ID1, &vid);
        if (ret)
                return dev_err_probe(dev, ret, "Failed to read VID\n");

        /* RT5739: (VID & MASK) must be 0 */
        if (vid & RT5739_VID_MASK)
                return dev_err_probe(dev, -ENODEV, "Incorrect VID (0x%02x)\n", vid);

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

        rt5739_init_regulator_desc(desc, vsel_acth, vid & RT5739_DID_MASK);

        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 rt5739_device_table[] = {
        { .compatible = "richtek,rt5733" },
        { .compatible = "richtek,rt5739" },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rt5739_device_table);

static struct i2c_driver rt5739_driver = {
        .driver = {
                .name = "rt5739",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = rt5739_device_table,
        },
        .probe = rt5739_probe,
};
module_i2c_driver(rt5739_driver);

MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
MODULE_DESCRIPTION("Richtek RT5739 regulator driver");
MODULE_LICENSE("GPL");