// SPDX-License-Identifier: GPL-2.0-only
/*
 * Regulator driver for National Semiconductors LP3972 PMIC chip
 *
 * Based on lp3971.c
 */

#include <linux/bug.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/lp3972.h>
#include <linux/slab.h>

struct lp3972 {
        struct device *dev;
        struct mutex io_lock;
        struct i2c_client *i2c;
};

/* LP3972 Control Registers */
#define LP3972_SCR_REG          0x07
#define LP3972_OVER1_REG        0x10
#define LP3972_OVSR1_REG        0x11
#define LP3972_OVER2_REG        0x12
#define LP3972_OVSR2_REG        0x13
#define LP3972_VCC1_REG         0x20
#define LP3972_ADTV1_REG        0x23
#define LP3972_ADTV2_REG        0x24
#define LP3972_AVRC_REG         0x25
#define LP3972_CDTC1_REG        0x26
#define LP3972_CDTC2_REG        0x27
#define LP3972_SDTV1_REG        0x29
#define LP3972_SDTV2_REG        0x2A
#define LP3972_MDTV1_REG        0x32
#define LP3972_MDTV2_REG        0x33
#define LP3972_L2VCR_REG        0x39
#define LP3972_L34VCR_REG       0x3A
#define LP3972_SCR1_REG         0x80
#define LP3972_SCR2_REG         0x81
#define LP3972_OEN3_REG         0x82
#define LP3972_OSR3_REG         0x83
#define LP3972_LOER4_REG        0x84
#define LP3972_B2TV_REG         0x85
#define LP3972_B3TV_REG         0x86
#define LP3972_B32RC_REG        0x87
#define LP3972_ISRA_REG         0x88
#define LP3972_BCCR_REG         0x89
#define LP3972_II1RR_REG        0x8E
#define LP3972_II2RR_REG        0x8F

#define LP3972_SYS_CONTROL1_REG         LP3972_SCR1_REG
/* System control register 1 initial value,
 * bits 5, 6 and 7 are EPROM programmable */
#define SYS_CONTROL1_INIT_VAL           0x02
#define SYS_CONTROL1_INIT_MASK          0x1F

#define LP3972_VOL_CHANGE_REG           LP3972_VCC1_REG
#define LP3972_VOL_CHANGE_FLAG_GO       0x01
#define LP3972_VOL_CHANGE_FLAG_MASK     0x03

/* LDO output enable mask */
#define LP3972_OEN3_L1EN        BIT(0)
#define LP3972_OVER2_LDO2_EN    BIT(2)
#define LP3972_OVER2_LDO3_EN    BIT(3)
#define LP3972_OVER2_LDO4_EN    BIT(4)
#define LP3972_OVER1_S_EN       BIT(2)

static const unsigned int ldo1_voltage_map[] = {
        1700000, 1725000, 1750000, 1775000, 1800000, 1825000, 1850000, 1875000,
        1900000, 1925000, 1950000, 1975000, 2000000,
};

static const unsigned int ldo23_voltage_map[] = {
        1800000, 1900000, 2000000, 2100000, 2200000, 2300000, 2400000, 2500000,
        2600000, 2700000, 2800000, 2900000, 3000000, 3100000, 3200000, 3300000,
};

static const unsigned int ldo4_voltage_map[] = {
        1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000, 1350000,
        1400000, 1500000, 1800000, 1900000, 2500000, 2800000, 3000000, 3300000,
};

static const unsigned int ldo5_voltage_map[] = {
              0,       0,       0,       0,       0,  850000,  875000,  900000,
         925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
        1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
        1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,
};

static const unsigned int buck1_voltage_map[] = {
         725000,  750000,  775000,  800000,  825000,  850000,  875000,  900000,
         925000,  950000,  975000, 1000000, 1025000, 1050000, 1075000, 1100000,
        1125000, 1150000, 1175000, 1200000, 1225000, 1250000, 1275000, 1300000,
        1325000, 1350000, 1375000, 1400000, 1425000, 1450000, 1475000, 1500000,
};

static const unsigned int buck23_voltage_map[] = {
              0,  800000,  850000,  900000,  950000, 1000000, 1050000, 1100000,
        1150000, 1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000,
        1550000, 1600000, 1650000, 1700000, 1800000, 1900000, 2500000, 2800000,
        3000000, 3300000,
};

static const int ldo_output_enable_mask[] = {
        LP3972_OEN3_L1EN,
        LP3972_OVER2_LDO2_EN,
        LP3972_OVER2_LDO3_EN,
        LP3972_OVER2_LDO4_EN,
        LP3972_OVER1_S_EN,
};

static const int ldo_output_enable_addr[] = {
        LP3972_OEN3_REG,
        LP3972_OVER2_REG,
        LP3972_OVER2_REG,
        LP3972_OVER2_REG,
        LP3972_OVER1_REG,
};

static const int ldo_vol_ctl_addr[] = {
        LP3972_MDTV1_REG,
        LP3972_L2VCR_REG,
        LP3972_L34VCR_REG,
        LP3972_L34VCR_REG,
        LP3972_SDTV1_REG,
};

static const int buck_vol_enable_addr[] = {
        LP3972_OVER1_REG,
        LP3972_OEN3_REG,
        LP3972_OEN3_REG,
};

static const int buck_base_addr[] = {
        LP3972_ADTV1_REG,
        LP3972_B2TV_REG,
        LP3972_B3TV_REG,
};

#define LP3972_LDO_OUTPUT_ENABLE_MASK(x) (ldo_output_enable_mask[x])
#define LP3972_LDO_OUTPUT_ENABLE_REG(x) (ldo_output_enable_addr[x])

/*      LDO voltage control registers shift:
        LP3972_LDO1 -> 0, LP3972_LDO2 -> 4
        LP3972_LDO3 -> 0, LP3972_LDO4 -> 4
        LP3972_LDO5 -> 0
*/
#define LP3972_LDO_VOL_CONTR_SHIFT(x) (((x) & 1) << 2)
#define LP3972_LDO_VOL_CONTR_REG(x) (ldo_vol_ctl_addr[x])
#define LP3972_LDO_VOL_CHANGE_SHIFT(x) ((x) ? 4 : 6)

#define LP3972_LDO_VOL_MASK(x) (((x) % 4) ? 0x0f : 0x1f)
#define LP3972_LDO_VOL_MIN_IDX(x) (((x) == 4) ? 0x05 : 0x00)
#define LP3972_LDO_VOL_MAX_IDX(x) ((x) ? (((x) == 4) ? 0x1f : 0x0f) : 0x0c)

#define LP3972_BUCK_VOL_ENABLE_REG(x) (buck_vol_enable_addr[x])
#define LP3972_BUCK_VOL1_REG(x) (buck_base_addr[x])
#define LP3972_BUCK_VOL_MASK 0x1f

static int lp3972_i2c_read(struct i2c_client *i2c, char reg, int count,
        u16 *dest)
{
        int ret;

        if (count != 1)
                return -EIO;
        ret = i2c_smbus_read_byte_data(i2c, reg);
        if (ret < 0)
                return ret;

        *dest = ret;
        return 0;
}

static int lp3972_i2c_write(struct i2c_client *i2c, char reg, int count,
        const u16 *src)
{
        if (count != 1)
                return -EIO;
        return i2c_smbus_write_byte_data(i2c, reg, *src);
}

static u8 lp3972_reg_read(struct lp3972 *lp3972, u8 reg)
{
        u16 val = 0;

        mutex_lock(&lp3972->io_lock);

        lp3972_i2c_read(lp3972->i2c, reg, 1, &val);

        dev_dbg(lp3972->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
                (unsigned)val & 0xff);

        mutex_unlock(&lp3972->io_lock);

        return val & 0xff;
}

static int lp3972_set_bits(struct lp3972 *lp3972, u8 reg, u16 mask, u16 val)
{
        u16 tmp;
        int ret;

        mutex_lock(&lp3972->io_lock);

        ret = lp3972_i2c_read(lp3972->i2c, reg, 1, &tmp);
        if (ret == 0) {
                tmp = (tmp & ~mask) | val;
                ret = lp3972_i2c_write(lp3972->i2c, reg, 1, &tmp);
                dev_dbg(lp3972->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
                        (unsigned)val & 0xff);
        }
        mutex_unlock(&lp3972->io_lock);

        return ret;
}

static int lp3972_ldo_is_enabled(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int ldo = rdev_get_id(dev) - LP3972_LDO1;
        u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);
        u16 val;

        val = lp3972_reg_read(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo));
        return !!(val & mask);
}

static int lp3972_ldo_enable(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int ldo = rdev_get_id(dev) - LP3972_LDO1;
        u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);

        return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
                                mask, mask);
}

static int lp3972_ldo_disable(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int ldo = rdev_get_id(dev) - LP3972_LDO1;
        u16 mask = LP3972_LDO_OUTPUT_ENABLE_MASK(ldo);

        return lp3972_set_bits(lp3972, LP3972_LDO_OUTPUT_ENABLE_REG(ldo),
                                mask, 0);
}

static int lp3972_ldo_get_voltage_sel(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int ldo = rdev_get_id(dev) - LP3972_LDO1;
        u16 mask = LP3972_LDO_VOL_MASK(ldo);
        u16 val, reg;

        reg = lp3972_reg_read(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo));
        val = (reg >> LP3972_LDO_VOL_CONTR_SHIFT(ldo)) & mask;

        return val;
}

static int lp3972_ldo_set_voltage_sel(struct regulator_dev *dev,
                                      unsigned int selector)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int ldo = rdev_get_id(dev) - LP3972_LDO1;
        int shift, ret;

        shift = LP3972_LDO_VOL_CONTR_SHIFT(ldo);
        ret = lp3972_set_bits(lp3972, LP3972_LDO_VOL_CONTR_REG(ldo),
                LP3972_LDO_VOL_MASK(ldo) << shift, selector << shift);

        if (ret)
                return ret;

        /*
         * LDO1 and LDO5 support voltage control by either target voltage1
         * or target voltage2 register.
         * We use target voltage1 register for LDO1 and LDO5 in this driver.
         * We need to update voltage change control register(0x20) to enable
         * LDO1 and LDO5 to change to their programmed target values.
         */
        switch (ldo) {
        case LP3972_LDO1:
        case LP3972_LDO5:
                shift = LP3972_LDO_VOL_CHANGE_SHIFT(ldo);
                ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
                        LP3972_VOL_CHANGE_FLAG_MASK << shift,
                        LP3972_VOL_CHANGE_FLAG_GO << shift);
                if (ret)
                        return ret;

                ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
                        LP3972_VOL_CHANGE_FLAG_MASK << shift, 0);
                break;
        }

        return ret;
}

static const struct regulator_ops lp3972_ldo_ops = {
        .list_voltage = regulator_list_voltage_table,
        .map_voltage = regulator_map_voltage_ascend,
        .is_enabled = lp3972_ldo_is_enabled,
        .enable = lp3972_ldo_enable,
        .disable = lp3972_ldo_disable,
        .get_voltage_sel = lp3972_ldo_get_voltage_sel,
        .set_voltage_sel = lp3972_ldo_set_voltage_sel,
};

static int lp3972_dcdc_is_enabled(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int buck = rdev_get_id(dev) - LP3972_DCDC1;
        u16 mask = 1 << (buck * 2);
        u16 val;

        val = lp3972_reg_read(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck));
        return !!(val & mask);
}

static int lp3972_dcdc_enable(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int buck = rdev_get_id(dev) - LP3972_DCDC1;
        u16 mask = 1 << (buck * 2);
        u16 val;

        val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
                                mask, mask);
        return val;
}

static int lp3972_dcdc_disable(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int buck = rdev_get_id(dev) - LP3972_DCDC1;
        u16 mask = 1 << (buck * 2);
        u16 val;

        val = lp3972_set_bits(lp3972, LP3972_BUCK_VOL_ENABLE_REG(buck),
                                mask, 0);
        return val;
}

static int lp3972_dcdc_get_voltage_sel(struct regulator_dev *dev)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int buck = rdev_get_id(dev) - LP3972_DCDC1;
        u16 reg;

        reg = lp3972_reg_read(lp3972, LP3972_BUCK_VOL1_REG(buck));
        reg &= LP3972_BUCK_VOL_MASK;

        return reg;
}

static int lp3972_dcdc_set_voltage_sel(struct regulator_dev *dev,
                                       unsigned int selector)
{
        struct lp3972 *lp3972 = rdev_get_drvdata(dev);
        int buck = rdev_get_id(dev) - LP3972_DCDC1;
        int ret;

        ret = lp3972_set_bits(lp3972, LP3972_BUCK_VOL1_REG(buck),
                                LP3972_BUCK_VOL_MASK, selector);
        if (ret)
                return ret;

        if (buck != 0)
                return ret;

        ret = lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
                LP3972_VOL_CHANGE_FLAG_MASK, LP3972_VOL_CHANGE_FLAG_GO);
        if (ret)
                return ret;

        return lp3972_set_bits(lp3972, LP3972_VOL_CHANGE_REG,
                                LP3972_VOL_CHANGE_FLAG_MASK, 0);
}

static const struct regulator_ops lp3972_dcdc_ops = {
        .list_voltage = regulator_list_voltage_table,
        .map_voltage = regulator_map_voltage_ascend,
        .is_enabled = lp3972_dcdc_is_enabled,
        .enable = lp3972_dcdc_enable,
        .disable = lp3972_dcdc_disable,
        .get_voltage_sel = lp3972_dcdc_get_voltage_sel,
        .set_voltage_sel = lp3972_dcdc_set_voltage_sel,
};

static const struct regulator_desc regulators[] = {
        {
                .name = "LDO1",
                .id = LP3972_LDO1,
                .ops = &lp3972_ldo_ops,
                .n_voltages = ARRAY_SIZE(ldo1_voltage_map),
                .volt_table = ldo1_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
        {
                .name = "LDO2",
                .id = LP3972_LDO2,
                .ops = &lp3972_ldo_ops,
                .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
                .volt_table = ldo23_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
        {
                .name = "LDO3",
                .id = LP3972_LDO3,
                .ops = &lp3972_ldo_ops,
                .n_voltages = ARRAY_SIZE(ldo23_voltage_map),
                .volt_table = ldo23_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
        {
                .name = "LDO4",
                .id = LP3972_LDO4,
                .ops = &lp3972_ldo_ops,
                .n_voltages = ARRAY_SIZE(ldo4_voltage_map),
                .volt_table = ldo4_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
        {
                .name = "LDO5",
                .id = LP3972_LDO5,
                .ops = &lp3972_ldo_ops,
                .n_voltages = ARRAY_SIZE(ldo5_voltage_map),
                .volt_table = ldo5_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
        {
                .name = "DCDC1",
                .id = LP3972_DCDC1,
                .ops = &lp3972_dcdc_ops,
                .n_voltages = ARRAY_SIZE(buck1_voltage_map),
                .volt_table = buck1_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
        {
                .name = "DCDC2",
                .id = LP3972_DCDC2,
                .ops = &lp3972_dcdc_ops,
                .n_voltages = ARRAY_SIZE(buck23_voltage_map),
                .volt_table = buck23_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
        {
                .name = "DCDC3",
                .id = LP3972_DCDC3,
                .ops = &lp3972_dcdc_ops,
                .n_voltages = ARRAY_SIZE(buck23_voltage_map),
                .volt_table = buck23_voltage_map,
                .type = REGULATOR_VOLTAGE,
                .owner = THIS_MODULE,
        },
};

static int setup_regulators(struct lp3972 *lp3972,
        struct lp3972_platform_data *pdata)
{
        int i, err;

        /* Instantiate the regulators */
        for (i = 0; i < pdata->num_regulators; i++) {
                struct lp3972_regulator_subdev *reg = &pdata->regulators[i];
                struct regulator_config config = { };
                struct regulator_dev *rdev;

                config.dev = lp3972->dev;
                config.init_data = reg->initdata;
                config.driver_data = lp3972;

                rdev = devm_regulator_register(lp3972->dev,
                                               &regulators[reg->id], &config);
                if (IS_ERR(rdev)) {
                        err = PTR_ERR(rdev);
                        dev_err(lp3972->dev, "regulator init failed: %d\n",
                                err);
                        return err;
                }
        }

        return 0;
}

static int lp3972_i2c_probe(struct i2c_client *i2c)
{
        struct lp3972 *lp3972;
        struct lp3972_platform_data *pdata = dev_get_platdata(&i2c->dev);
        int ret;
        u16 val;

        if (!pdata) {
                dev_dbg(&i2c->dev, "No platform init data supplied\n");
                return -ENODEV;
        }

        lp3972 = devm_kzalloc(&i2c->dev, sizeof(struct lp3972), GFP_KERNEL);
        if (!lp3972)
                return -ENOMEM;

        lp3972->i2c = i2c;
        lp3972->dev = &i2c->dev;

        mutex_init(&lp3972->io_lock);

        /* Detect LP3972 */
        ret = lp3972_i2c_read(i2c, LP3972_SYS_CONTROL1_REG, 1, &val);
        if (ret == 0 &&
                (val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL) {
                ret = -ENODEV;
                dev_err(&i2c->dev, "chip reported: val = 0x%x\n", val);
        }
        if (ret < 0) {
                dev_err(&i2c->dev, "failed to detect device. ret = %d\n", ret);
                return ret;
        }

        ret = setup_regulators(lp3972, pdata);
        if (ret < 0)
                return ret;

        i2c_set_clientdata(i2c, lp3972);
        return 0;
}

static const struct i2c_device_id lp3972_i2c_id[] = {
        { "lp3972" },
        { }
};
MODULE_DEVICE_TABLE(i2c, lp3972_i2c_id);

static struct i2c_driver lp3972_i2c_driver = {
        .driver = {
                .name = "lp3972",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .probe = lp3972_i2c_probe,
        .id_table = lp3972_i2c_id,
};

static int __init lp3972_module_init(void)
{
        return i2c_add_driver(&lp3972_i2c_driver);
}
subsys_initcall(lp3972_module_init);

static void __exit lp3972_module_exit(void)
{
        i2c_del_driver(&lp3972_i2c_driver);
}
module_exit(lp3972_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Axel Lin <axel.lin@gmail.com>");
MODULE_DESCRIPTION("LP3972 PMIC driver");