root/drivers/regulator/rt4831-regulator.c
// SPDX-License-Identifier: GPL-2.0-only

#include <linux/bitops.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#include <linux/regulator/driver.h>

enum {
        DSV_OUT_VLCM = 0,
        DSV_OUT_VPOS,
        DSV_OUT_VNEG,
        DSV_OUT_MAX
};

#define RT4831_REG_DSVEN        0x09
#define RT4831_REG_VLCM         0x0c
#define RT4831_REG_VPOS         0x0d
#define RT4831_REG_VNEG         0x0e
#define RT4831_REG_FLAGS        0x0f

#define RT4831_VOLT_MASK        GENMASK(5, 0)
#define RT4831_DSVMODE_SHIFT    5
#define RT4831_DSVMODE_MASK     GENMASK(7, 5)
#define RT4831_POSADEN_MASK     BIT(4)
#define RT4831_NEGADEN_MASK     BIT(3)
#define RT4831_POSEN_MASK       BIT(2)
#define RT4831_NEGEN_MASK       BIT(1)

#define RT4831_OTP_MASK         BIT(6)
#define RT4831_LCMOVP_MASK      BIT(5)
#define RT4831_VPOSSCP_MASK     BIT(3)
#define RT4831_VNEGSCP_MASK     BIT(2)

#define DSV_MODE_NORMAL         (0x4 << RT4831_DSVMODE_SHIFT)
#define DSV_MODE_BYPASS         (0x6 << RT4831_DSVMODE_SHIFT)
#define STEP_UV                 50000
#define VLCM_MIN_UV             4000000
#define VLCM_MAX_UV             7150000
#define VLCM_N_VOLTAGES         ((VLCM_MAX_UV - VLCM_MIN_UV) / STEP_UV + 1)
#define VPN_MIN_UV              4000000
#define VPN_MAX_UV              6500000
#define VPN_N_VOLTAGES          ((VPN_MAX_UV - VPN_MIN_UV) / STEP_UV + 1)

static int rt4831_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
{
        struct regmap *regmap = rdev_get_regmap(rdev);
        int rid = rdev_get_id(rdev);
        unsigned int val, events = 0;
        int ret;

        ret = regmap_read(regmap, RT4831_REG_FLAGS, &val);
        if (ret)
                return ret;

        if (val & RT4831_OTP_MASK)
                events |= REGULATOR_ERROR_OVER_TEMP;

        if (rid == DSV_OUT_VLCM && (val & RT4831_LCMOVP_MASK))
                events |= REGULATOR_ERROR_OVER_CURRENT;

        if (rid == DSV_OUT_VPOS && (val & RT4831_VPOSSCP_MASK))
                events |= REGULATOR_ERROR_OVER_CURRENT;

        if (rid == DSV_OUT_VNEG && (val & RT4831_VNEGSCP_MASK))
                events |= REGULATOR_ERROR_OVER_CURRENT;

        *flags = events;
        return 0;
}

static const struct regulator_ops rt4831_dsvlcm_ops = {
        .list_voltage = regulator_list_voltage_linear,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_bypass = regulator_set_bypass_regmap,
        .get_bypass = regulator_get_bypass_regmap,
        .get_error_flags = rt4831_get_error_flags,
};

static const struct regulator_ops rt4831_dsvpn_ops = {
        .list_voltage = regulator_list_voltage_linear,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_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,
        .get_error_flags = rt4831_get_error_flags,
};

static const struct regulator_desc rt4831_regulator_descs[] = {
        {
                .name = "DSVLCM",
                .ops = &rt4831_dsvlcm_ops,
                .of_match = of_match_ptr("DSVLCM"),
                .regulators_node = of_match_ptr("regulators"),
                .type = REGULATOR_VOLTAGE,
                .id = DSV_OUT_VLCM,
                .n_voltages = VLCM_N_VOLTAGES,
                .min_uV = VLCM_MIN_UV,
                .uV_step = STEP_UV,
                .vsel_reg = RT4831_REG_VLCM,
                .vsel_mask = RT4831_VOLT_MASK,
                .bypass_reg = RT4831_REG_DSVEN,
                .bypass_mask = RT4831_DSVMODE_MASK,
                .bypass_val_on = DSV_MODE_BYPASS,
                .bypass_val_off = DSV_MODE_NORMAL,
                .owner = THIS_MODULE,
        },
        {
                .name = "DSVP",
                .ops = &rt4831_dsvpn_ops,
                .of_match = of_match_ptr("DSVP"),
                .regulators_node = of_match_ptr("regulators"),
                .type = REGULATOR_VOLTAGE,
                .id = DSV_OUT_VPOS,
                .n_voltages = VPN_N_VOLTAGES,
                .min_uV = VPN_MIN_UV,
                .uV_step = STEP_UV,
                .vsel_reg = RT4831_REG_VPOS,
                .vsel_mask = RT4831_VOLT_MASK,
                .enable_reg = RT4831_REG_DSVEN,
                .enable_mask = RT4831_POSEN_MASK,
                .active_discharge_reg = RT4831_REG_DSVEN,
                .active_discharge_mask = RT4831_POSADEN_MASK,
                .active_discharge_on = RT4831_POSADEN_MASK,
                .owner = THIS_MODULE,
        },
        {
                .name = "DSVN",
                .ops = &rt4831_dsvpn_ops,
                .of_match = of_match_ptr("DSVN"),
                .regulators_node = of_match_ptr("regulators"),
                .type = REGULATOR_VOLTAGE,
                .id = DSV_OUT_VNEG,
                .n_voltages = VPN_N_VOLTAGES,
                .min_uV = VPN_MIN_UV,
                .uV_step = STEP_UV,
                .vsel_reg = RT4831_REG_VNEG,
                .vsel_mask = RT4831_VOLT_MASK,
                .enable_reg = RT4831_REG_DSVEN,
                .enable_mask = RT4831_NEGEN_MASK,
                .active_discharge_reg = RT4831_REG_DSVEN,
                .active_discharge_mask = RT4831_NEGADEN_MASK,
                .active_discharge_on = RT4831_NEGADEN_MASK,
                .owner = THIS_MODULE,
        }
};

static int rt4831_regulator_probe(struct platform_device *pdev)
{
        struct regmap *regmap;
        struct regulator_dev *rdev;
        struct regulator_config config = {};
        int i, ret;

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

        /* Configure DSV mode to normal by default */
        ret = regmap_update_bits(regmap, RT4831_REG_DSVEN, RT4831_DSVMODE_MASK, DSV_MODE_NORMAL);
        if (ret) {
                dev_err(&pdev->dev, "Failed to configure dsv mode to normal\n");
                return ret;
        }

        config.dev = pdev->dev.parent;
        config.regmap = regmap;

        for (i = 0; i < DSV_OUT_MAX; i++) {
                rdev = devm_regulator_register(&pdev->dev, rt4831_regulator_descs + i, &config);
                if (IS_ERR(rdev)) {
                        dev_err(&pdev->dev, "Failed to register %d regulator\n", i);
                        return PTR_ERR(rdev);
                }
        }

        return 0;
}

static const struct platform_device_id rt4831_regulator_match[] = {
        { "rt4831-regulator", 0 },
        {}
};
MODULE_DEVICE_TABLE(platform, rt4831_regulator_match);

static struct platform_driver rt4831_regulator_driver = {
        .driver = {
                .name = "rt4831-regulator",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .id_table = rt4831_regulator_match,
        .probe = rt4831_regulator_probe,
};
module_platform_driver(rt4831_regulator_driver);

MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
MODULE_DESCRIPTION("Richtek RT4831 DSV Regulators driver");
MODULE_LICENSE("GPL v2");