// SPDX-License-Identifier: GPL-2.0
//
// Copyright (c) 2022 Collabora Ltd.
// Author: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
//
// Based on mt6323-regulator.c,
//     Copyright (c) 2016 MediaTek Inc.
//

#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/mt6397/core.h>
#include <linux/mfd/mt6332/registers.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/mt6332-regulator.h>
#include <linux/regulator/of_regulator.h>

#define MT6332_LDO_MODE_NORMAL  0
#define MT6332_LDO_MODE_LP      1

/*
 * MT6332 regulators information
 *
 * @desc: standard fields of regulator description.
 * @qi: Mask for query enable signal status of regulators
 * @vselon_reg: Register sections for hardware control mode of bucks
 * @vselctrl_reg: Register for controlling the buck control mode.
 * @vselctrl_mask: Mask for query buck's voltage control mode.
 * @status_reg: Register for regulator enable status where qi unavailable
 * @status_mask: Mask for querying regulator enable status
 */
struct mt6332_regulator_info {
        struct regulator_desc desc;
        u32 qi;
        u32 vselon_reg;
        u32 vselctrl_reg;
        u32 vselctrl_mask;
        u32 modeset_reg;
        u32 modeset_mask;
        u32 status_reg;
        u32 status_mask;
};

#define MT6332_BUCK(match, vreg, min, max, step, volt_ranges, enreg,    \
                vosel, vosel_mask, voselon, vosel_ctrl)                 \
[MT6332_ID_##vreg] = {                                                  \
        .desc = {                                                       \
                .name = #vreg,                                          \
                .of_match = of_match_ptr(match),                        \
                .ops = &mt6332_buck_volt_range_ops,                     \
                .type = REGULATOR_VOLTAGE,                              \
                .id = MT6332_ID_##vreg,                                 \
                .owner = THIS_MODULE,                                   \
                .n_voltages = (max - min)/step + 1,                     \
                .linear_ranges = volt_ranges,                           \
                .n_linear_ranges = ARRAY_SIZE(volt_ranges),             \
                .vsel_reg = vosel,                                      \
                .vsel_mask = vosel_mask,                                \
                .enable_reg = enreg,                                    \
                .enable_mask = BIT(0),                                  \
        },                                                              \
        .qi = BIT(13),                                                  \
        .vselon_reg = voselon,                                          \
        .vselctrl_reg = vosel_ctrl,                                     \
        .vselctrl_mask = BIT(1),                                        \
        .status_mask = 0,                                               \
}

#define MT6332_LDO_LINEAR(match, vreg, min, max, step, volt_ranges,     \
                          enreg, vosel, vosel_mask, voselon,            \
                          vosel_ctrl, _modeset_reg, _modeset_mask)      \
[MT6332_ID_##vreg] = {                                                  \
        .desc = {                                                       \
                .name = #vreg,                                          \
                .of_match = of_match_ptr(match),                        \
                .ops = &mt6332_ldo_volt_range_ops,                      \
                .type = REGULATOR_VOLTAGE,                              \
                .id = MT6332_ID_##vreg,                                 \
                .owner = THIS_MODULE,                                   \
                .n_voltages = (max - min)/step + 1,                     \
                .linear_ranges = volt_ranges,                           \
                .n_linear_ranges = ARRAY_SIZE(volt_ranges),             \
                .vsel_reg = vosel,                                      \
                .vsel_mask = vosel_mask,                                \
                .enable_reg = enreg,                                    \
                .enable_mask = BIT(0),                                  \
        },                                                              \
        .qi = BIT(15),                                                  \
        .vselon_reg = voselon,                                          \
        .vselctrl_reg = vosel_ctrl,                                     \
        .vselctrl_mask = BIT(1),                                        \
        .modeset_reg = _modeset_reg,                                    \
        .modeset_mask = _modeset_mask,                                  \
        .status_mask = 0,                                               \
}

#define MT6332_LDO_AO(match, vreg, ldo_volt_table, vosel, vosel_mask)   \
[MT6332_ID_##vreg] = {                                                  \
        .desc = {                                                       \
                .name = #vreg,                                          \
                .of_match = of_match_ptr(match),                        \
                .ops = &mt6332_volt_table_ao_ops,                       \
                .type = REGULATOR_VOLTAGE,                              \
                .id = MT6332_ID_##vreg,                                 \
                .owner = THIS_MODULE,                                   \
                .n_voltages = ARRAY_SIZE(ldo_volt_table),               \
                .volt_table = ldo_volt_table,                           \
                .vsel_reg = vosel,                                      \
                .vsel_mask = vosel_mask,                                \
        },                                                              \
}

#define MT6332_LDO(match, vreg, ldo_volt_table, enreg, enbit, vosel,    \
                   vosel_mask, _modeset_reg, _modeset_mask)             \
[MT6332_ID_##vreg] = {                                                  \
        .desc = {                                                       \
                .name = #vreg,                                          \
                .of_match = of_match_ptr(match),                        \
                .ops = &mt6332_volt_table_ops,                          \
                .type = REGULATOR_VOLTAGE,                              \
                .id = MT6332_ID_##vreg,                                 \
                .owner = THIS_MODULE,                                   \
                .n_voltages = ARRAY_SIZE(ldo_volt_table),               \
                .volt_table = ldo_volt_table,                           \
                .vsel_reg = vosel,                                      \
                .vsel_mask = vosel_mask,                                \
                .enable_reg = enreg,                                    \
                .enable_mask = BIT(enbit),                              \
        },                                                              \
        .qi = BIT(15),                                                  \
        .modeset_reg = _modeset_reg,                                    \
        .modeset_mask = _modeset_mask,                                  \
        .status_mask = 0,                                               \
}

#define MT6332_REG_FIXED(match, vreg, enreg, enbit, qibit, volt, stbit) \
[MT6332_ID_##vreg] = {                                                  \
        .desc = {                                                       \
                .name = #vreg,                                          \
                .of_match = of_match_ptr(match),                        \
                .ops = &mt6332_volt_fixed_ops,                          \
                .type = REGULATOR_VOLTAGE,                              \
                .id = MT6332_ID_##vreg,                                 \
                .owner = THIS_MODULE,                                   \
                .n_voltages = 1,                                        \
                .enable_reg = enreg,                                    \
                .enable_mask = BIT(enbit),                              \
                .min_uV = volt,                                         \
        },                                                              \
        .qi = BIT(qibit),                                               \
        .status_reg = MT6332_EN_STATUS0,                                \
        .status_mask = BIT(stbit),                                      \
}

static const struct linear_range boost_volt_range[] = {
        REGULATOR_LINEAR_RANGE(3500000, 0, 0x7f, 31250),
};

static const struct linear_range buck_volt_range[] = {
        REGULATOR_LINEAR_RANGE(700000, 0, 0x7f, 6250),
};

static const struct linear_range buck_pa_volt_range[] = {
        REGULATOR_LINEAR_RANGE(500000, 0, 0x3f, 50000),
};

static const struct linear_range buck_rf_volt_range[] = {
        REGULATOR_LINEAR_RANGE(1050000, 0, 0x7f, 9375),
};

static const unsigned int ldo_volt_table1[] = {
        2800000, 3000000, 0, 3200000
};

static const unsigned int ldo_volt_table2[] = {
        1200000, 1300000, 1400000, 1500000, 1600000, 1700000, 1800000, 1800000,
};

static int mt6332_get_status(struct regulator_dev *rdev)
{
        struct mt6332_regulator_info *info = rdev_get_drvdata(rdev);
        u32 reg, en_mask, regval;
        int ret;

        if (info->qi > 0) {
                reg = info->desc.enable_reg;
                en_mask = info->qi;
        } else {
                reg = info->status_reg;
                en_mask = info->status_mask;
        }

        ret = regmap_read(rdev->regmap, reg, &regval);
        if (ret != 0) {
                dev_err(&rdev->dev, "Failed to get enable reg: %d\n", ret);
                return ret;
        }

        return (regval & en_mask) ? REGULATOR_STATUS_ON : REGULATOR_STATUS_OFF;
}

static int mt6332_ldo_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
        struct mt6332_regulator_info *info = rdev_get_drvdata(rdev);
        int val;

        switch (mode) {
        case REGULATOR_MODE_STANDBY:
                val = MT6332_LDO_MODE_LP;
                break;
        case REGULATOR_MODE_NORMAL:
                val = MT6332_LDO_MODE_NORMAL;
                break;
        default:
                return -EINVAL;
        }

        val <<= ffs(info->modeset_mask) - 1;

        return regmap_update_bits(rdev->regmap, info->modeset_reg,
                                  info->modeset_mask, val);
}

static unsigned int mt6332_ldo_get_mode(struct regulator_dev *rdev)
{
        struct mt6332_regulator_info *info = rdev_get_drvdata(rdev);
        unsigned int val;
        int ret;

        ret = regmap_read(rdev->regmap, info->modeset_reg, &val);
        if (ret < 0)
                return ret;

        val &= info->modeset_mask;
        val >>= ffs(info->modeset_mask) - 1;

        return (val & BIT(0)) ? REGULATOR_MODE_STANDBY : REGULATOR_MODE_NORMAL;
}

static const struct regulator_ops mt6332_buck_volt_range_ops = {
        .list_voltage = regulator_list_voltage_linear_range,
        .map_voltage = regulator_map_voltage_linear_range,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_voltage_time_sel = regulator_set_voltage_time_sel,
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .get_status = mt6332_get_status,
};

static const struct regulator_ops mt6332_ldo_volt_range_ops = {
        .list_voltage = regulator_list_voltage_linear_range,
        .map_voltage = regulator_map_voltage_linear_range,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_voltage_time_sel = regulator_set_voltage_time_sel,
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .get_status = mt6332_get_status,
        .set_mode = mt6332_ldo_set_mode,
        .get_mode = mt6332_ldo_get_mode,
};

static const struct regulator_ops mt6332_volt_table_ops = {
        .list_voltage = regulator_list_voltage_table,
        .map_voltage = regulator_map_voltage_iterate,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_voltage_time_sel = regulator_set_voltage_time_sel,
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .get_status = mt6332_get_status,
        .set_mode = mt6332_ldo_set_mode,
        .get_mode = mt6332_ldo_get_mode,
};

static const struct regulator_ops mt6332_volt_table_ao_ops = {
        .list_voltage = regulator_list_voltage_table,
        .map_voltage = regulator_map_voltage_iterate,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_voltage_time_sel = regulator_set_voltage_time_sel,
};

static const struct regulator_ops mt6332_volt_fixed_ops = {
        .list_voltage = regulator_list_voltage_linear,
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .get_status = mt6332_get_status,
};

/* The array is indexed by id(MT6332_ID_XXX) */
static struct mt6332_regulator_info mt6332_regulators[] = {
        MT6332_BUCK("buck-vdram", VDRAM, 700000, 1493750, 6250, buck_volt_range,
                    MT6332_EN_STATUS0, MT6332_VDRAM_CON11, GENMASK(6, 0),
                    MT6332_VDRAM_CON12, MT6332_VDRAM_CON7),
        MT6332_BUCK("buck-vdvfs2", VDVFS2, 700000, 1312500, 6250, buck_volt_range,
                    MT6332_VDVFS2_CON9, MT6332_VDVFS2_CON11, GENMASK(6, 0),
                    MT6332_VDVFS2_CON12, MT6332_VDVFS2_CON7),
        MT6332_BUCK("buck-vpa", VPA, 500000, 3400000, 50000, buck_pa_volt_range,
                    MT6332_VPA_CON9, MT6332_VPA_CON11, GENMASK(5, 0),
                    MT6332_VPA_CON12, MT6332_VPA_CON7),
        MT6332_BUCK("buck-vrf18a", VRF1, 1050000, 2240625, 9375, buck_rf_volt_range,
                    MT6332_VRF1_CON9, MT6332_VRF1_CON11, GENMASK(6, 0),
                    MT6332_VRF1_CON12, MT6332_VRF1_CON7),
        MT6332_BUCK("buck-vrf18b", VRF2, 1050000, 2240625, 9375, buck_rf_volt_range,
                    MT6332_VRF2_CON9, MT6332_VRF2_CON11, GENMASK(6, 0),
                    MT6332_VRF2_CON12, MT6332_VRF2_CON7),
        MT6332_BUCK("buck-vsbst", VSBST, 3500000, 7468750, 31250, boost_volt_range,
                    MT6332_VSBST_CON8, MT6332_VSBST_CON12, GENMASK(6, 0),
                    MT6332_VSBST_CON13, MT6332_VSBST_CON8),
        MT6332_LDO("ldo-vauxb32", VAUXB32, ldo_volt_table1, MT6332_LDO_CON1, 10,
                   MT6332_LDO_CON9, GENMASK(6, 5), MT6332_LDO_CON1, GENMASK(1, 0)),
        MT6332_REG_FIXED("ldo-vbif28", VBIF28, MT6332_LDO_CON2, 10, 0, 2800000, 1),
        MT6332_REG_FIXED("ldo-vusb33", VUSB33, MT6332_LDO_CON3, 10, 0, 3300000, 2),
        MT6332_LDO_LINEAR("ldo-vsram", VSRAM_DVFS2, 700000, 1493750, 6250, buck_volt_range,
                          MT6332_EN_STATUS0, MT6332_LDO_CON8, GENMASK(15, 9),
                          MT6332_VDVFS2_CON23, MT6332_VDVFS2_CON22,
                          MT6332_LDO_CON5, GENMASK(1, 0)),
        MT6332_LDO_AO("ldo-vdig18", VDIG18, ldo_volt_table2, MT6332_LDO_CON12, GENMASK(11, 9)),
};

static int mt6332_set_buck_vosel_reg(struct platform_device *pdev)
{
        struct mt6397_chip *mt6332 = dev_get_drvdata(pdev->dev.parent);
        int i;
        u32 regval;

        for (i = 0; i < MT6332_ID_VREG_MAX; i++) {
                if (mt6332_regulators[i].vselctrl_reg) {
                        if (regmap_read(mt6332->regmap,
                                mt6332_regulators[i].vselctrl_reg,
                                &regval) < 0) {
                                dev_err(&pdev->dev,
                                        "Failed to read buck ctrl\n");
                                return -EIO;
                        }

                        if (regval & mt6332_regulators[i].vselctrl_mask) {
                                mt6332_regulators[i].desc.vsel_reg =
                                mt6332_regulators[i].vselon_reg;
                        }
                }
        }

        return 0;
}

static int mt6332_regulator_probe(struct platform_device *pdev)
{
        struct mt6397_chip *mt6332 = dev_get_drvdata(pdev->dev.parent);
        struct regulator_config config = {};
        struct regulator_dev *rdev;
        int i;
        u32 reg_value;

        /* Query buck controller to select activated voltage register part */
        if (mt6332_set_buck_vosel_reg(pdev))
                return -EIO;

        /* Read PMIC chip revision to update constraints and voltage table */
        if (regmap_read(mt6332->regmap, MT6332_HWCID, &reg_value) < 0) {
                dev_err(&pdev->dev, "Failed to read Chip ID\n");
                return -EIO;
        }
        reg_value &= GENMASK(7, 0);

        dev_info(&pdev->dev, "Chip ID = 0x%x\n", reg_value);

        /*
         * ChipID 0x10 is "MT6332 E1", has a different voltage table and
         * it's currently not supported in this driver. Upon detection of
         * this ID, refuse to register the regulators, as we will wrongly
         * interpret the VSEL for this revision, potentially overvolting
         * some device.
         */
        if (reg_value == 0x10) {
                dev_err(&pdev->dev, "Chip version not supported. Bailing out.\n");
                return -EINVAL;
        }

        for (i = 0; i < MT6332_ID_VREG_MAX; i++) {
                config.dev = &pdev->dev;
                config.driver_data = &mt6332_regulators[i];
                config.regmap = mt6332->regmap;
                rdev = devm_regulator_register(&pdev->dev,
                                &mt6332_regulators[i].desc, &config);
                if (IS_ERR(rdev)) {
                        dev_err(&pdev->dev, "failed to register %s\n",
                                mt6332_regulators[i].desc.name);
                        return PTR_ERR(rdev);
                }
        }
        return 0;
}

static const struct platform_device_id mt6332_platform_ids[] = {
        {"mt6332-regulator", 0},
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(platform, mt6332_platform_ids);

static struct platform_driver mt6332_regulator_driver = {
        .driver = {
                .name = "mt6332-regulator",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .probe = mt6332_regulator_probe,
        .id_table = mt6332_platform_ids,
};

module_platform_driver(mt6332_regulator_driver);

MODULE_AUTHOR("AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>");
MODULE_DESCRIPTION("Regulator Driver for MediaTek MT6332 PMIC");
MODULE_LICENSE("GPL");