// SPDX-License-Identifier: GPL-2.0-only
/*
 * LP8755 High Performance Power Management Unit : System Interface Driver
 * (based on rev. 0.26)
 * Copyright 2012 Texas Instruments
 *
 * Author: Daniel(Geon Si) Jeong <daniel.jeong@ti.com>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/uaccess.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/platform_data/lp8755.h>

#define LP8755_REG_BUCK0        0x00
#define LP8755_REG_BUCK1        0x03
#define LP8755_REG_BUCK2        0x04
#define LP8755_REG_BUCK3        0x01
#define LP8755_REG_BUCK4        0x05
#define LP8755_REG_BUCK5        0x02
#define LP8755_REG_MAX          0xFF

#define LP8755_BUCK_EN_M        BIT(7)
#define LP8755_BUCK_LINEAR_OUT_MAX      0x76
#define LP8755_BUCK_VOUT_M      0x7F

struct lp8755_mphase {
        int nreg;
        int buck_num[LP8755_BUCK_MAX];
};

struct lp8755_chip {
        struct device *dev;
        struct regmap *regmap;
        struct lp8755_platform_data *pdata;

        int irq;
        unsigned int irqmask;

        int mphase;
        struct regulator_dev *rdev[LP8755_BUCK_MAX];
};

static int lp8755_buck_enable_time(struct regulator_dev *rdev)
{
        int ret;
        unsigned int regval;
        enum lp8755_bucks id = rdev_get_id(rdev);

        ret = regmap_read(rdev->regmap, 0x12 + id, &regval);
        if (ret < 0) {
                dev_err(&rdev->dev, "i2c access error %s\n", __func__);
                return ret;
        }
        return (regval & 0xff) * 100;
}

static int lp8755_buck_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
        int ret;
        unsigned int regbval = 0x0;
        enum lp8755_bucks id = rdev_get_id(rdev);
        struct lp8755_chip *pchip = rdev_get_drvdata(rdev);

        switch (mode) {
        case REGULATOR_MODE_FAST:
                /* forced pwm mode */
                regbval = (0x01 << id);
                break;
        case REGULATOR_MODE_NORMAL:
                /* enable automatic pwm/pfm mode */
                ret = regmap_update_bits(rdev->regmap, 0x08 + id, 0x20, 0x00);
                if (ret < 0)
                        goto err_i2c;
                break;
        case REGULATOR_MODE_IDLE:
                /* enable automatic pwm/pfm/lppfm mode */
                ret = regmap_update_bits(rdev->regmap, 0x08 + id, 0x20, 0x20);
                if (ret < 0)
                        goto err_i2c;

                ret = regmap_update_bits(rdev->regmap, 0x10, 0x01, 0x01);
                if (ret < 0)
                        goto err_i2c;
                break;
        default:
                dev_err(pchip->dev, "Not supported buck mode %s\n", __func__);
                /* forced pwm mode */
                regbval = (0x01 << id);
        }

        ret = regmap_update_bits(rdev->regmap, 0x06, 0x01 << id, regbval);
        if (ret < 0)
                goto err_i2c;
        return ret;
err_i2c:
        dev_err(&rdev->dev, "i2c access error %s\n", __func__);
        return ret;
}

static unsigned int lp8755_buck_get_mode(struct regulator_dev *rdev)
{
        int ret;
        unsigned int regval;
        enum lp8755_bucks id = rdev_get_id(rdev);

        ret = regmap_read(rdev->regmap, 0x06, &regval);
        if (ret < 0)
                goto err_i2c;

        /* mode fast means forced pwm mode */
        if (regval & (0x01 << id))
                return REGULATOR_MODE_FAST;

        ret = regmap_read(rdev->regmap, 0x08 + id, &regval);
        if (ret < 0)
                goto err_i2c;

        /* mode idle means automatic pwm/pfm/lppfm mode */
        if (regval & 0x20)
                return REGULATOR_MODE_IDLE;

        /* mode normal means automatic pwm/pfm mode */
        return REGULATOR_MODE_NORMAL;

err_i2c:
        dev_err(&rdev->dev, "i2c access error %s\n", __func__);
        return 0;
}

static const unsigned int lp8755_buck_ramp_table[] = {
        30000, 15000, 7500, 3800, 1900, 940, 470, 230
};

static const struct regulator_ops lp8755_buck_ops = {
        .map_voltage = regulator_map_voltage_linear,
        .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,
        .enable_time = lp8755_buck_enable_time,
        .set_mode = lp8755_buck_set_mode,
        .get_mode = lp8755_buck_get_mode,
        .set_ramp_delay = regulator_set_ramp_delay_regmap,
};

#define lp8755_rail(_id) "lp8755_buck"#_id
#define lp8755_buck_init(_id)\
{\
        .constraints = {\
                .name = lp8755_rail(_id),\
                .valid_ops_mask = REGULATOR_CHANGE_VOLTAGE,\
                .min_uV = 500000,\
                .max_uV = 1675000,\
        },\
}

static struct regulator_init_data lp8755_reg_default[LP8755_BUCK_MAX] = {
        [LP8755_BUCK0] = lp8755_buck_init(0),
        [LP8755_BUCK1] = lp8755_buck_init(1),
        [LP8755_BUCK2] = lp8755_buck_init(2),
        [LP8755_BUCK3] = lp8755_buck_init(3),
        [LP8755_BUCK4] = lp8755_buck_init(4),
        [LP8755_BUCK5] = lp8755_buck_init(5),
};

static const struct lp8755_mphase mphase_buck[MPHASE_CONF_MAX] = {
        { 3, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK5 } },
        { 6, { LP8755_BUCK0, LP8755_BUCK1, LP8755_BUCK2, LP8755_BUCK3,
               LP8755_BUCK4, LP8755_BUCK5 } },
        { 5, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK4,
               LP8755_BUCK5} },
        { 4, { LP8755_BUCK0, LP8755_BUCK3, LP8755_BUCK4, LP8755_BUCK5} },
        { 3, { LP8755_BUCK0, LP8755_BUCK4, LP8755_BUCK5} },
        { 2, { LP8755_BUCK0, LP8755_BUCK5} },
        { 1, { LP8755_BUCK0} },
        { 2, { LP8755_BUCK0, LP8755_BUCK3} },
        { 4, { LP8755_BUCK0, LP8755_BUCK2, LP8755_BUCK3, LP8755_BUCK5} },
};

static int lp8755_init_data(struct lp8755_chip *pchip)
{
        unsigned int regval;
        int ret, icnt, buck_num;
        struct lp8755_platform_data *pdata = pchip->pdata;

        /* read back  muti-phase configuration */
        ret = regmap_read(pchip->regmap, 0x3D, &regval);
        if (ret < 0)
                goto out_i2c_error;
        pchip->mphase = regval & 0x0F;

        /* set default data based on multi-phase config */
        for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
                buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
                pdata->buck_data[buck_num] = &lp8755_reg_default[buck_num];
        }
        return ret;

out_i2c_error:
        dev_err(pchip->dev, "i2c access error %s\n", __func__);
        return ret;
}

#define lp8755_buck_desc(_id)\
{\
        .name = lp8755_rail(_id),\
        .id   = LP8755_BUCK##_id,\
        .ops  = &lp8755_buck_ops,\
        .n_voltages = LP8755_BUCK_LINEAR_OUT_MAX+1,\
        .uV_step = 10000,\
        .min_uV = 500000,\
        .type = REGULATOR_VOLTAGE,\
        .owner = THIS_MODULE,\
        .enable_reg = LP8755_REG_BUCK##_id,\
        .enable_mask = LP8755_BUCK_EN_M,\
        .vsel_reg = LP8755_REG_BUCK##_id,\
        .vsel_mask = LP8755_BUCK_VOUT_M,\
        .ramp_reg = (LP8755_BUCK##_id) + 0x7,\
        .ramp_mask = 0x7,\
        .ramp_delay_table = lp8755_buck_ramp_table,\
        .n_ramp_values = ARRAY_SIZE(lp8755_buck_ramp_table),\
}

static const struct regulator_desc lp8755_regulators[] = {
        lp8755_buck_desc(0),
        lp8755_buck_desc(1),
        lp8755_buck_desc(2),
        lp8755_buck_desc(3),
        lp8755_buck_desc(4),
        lp8755_buck_desc(5),
};

static int lp8755_regulator_init(struct lp8755_chip *pchip)
{
        int ret, icnt, buck_num;
        struct lp8755_platform_data *pdata = pchip->pdata;
        struct regulator_config rconfig = { };

        rconfig.regmap = pchip->regmap;
        rconfig.dev = pchip->dev;
        rconfig.driver_data = pchip;

        for (icnt = 0; icnt < mphase_buck[pchip->mphase].nreg; icnt++) {
                buck_num = mphase_buck[pchip->mphase].buck_num[icnt];
                rconfig.init_data = pdata->buck_data[buck_num];
                rconfig.of_node = pchip->dev->of_node;
                pchip->rdev[buck_num] =
                    devm_regulator_register(pchip->dev,
                                    &lp8755_regulators[buck_num], &rconfig);
                if (IS_ERR(pchip->rdev[buck_num])) {
                        ret = PTR_ERR(pchip->rdev[buck_num]);
                        pchip->rdev[buck_num] = NULL;
                        dev_err(pchip->dev, "regulator init failed: buck %d\n",
                                buck_num);
                        return ret;
                }
        }

        return 0;
}

static irqreturn_t lp8755_irq_handler(int irq, void *data)
{
        int ret, icnt;
        unsigned int flag0, flag1;
        struct lp8755_chip *pchip = data;

        /* read flag0 register */
        ret = regmap_read(pchip->regmap, 0x0D, &flag0);
        if (ret < 0)
                goto err_i2c;
        /* clear flag register to pull up int. pin */
        ret = regmap_write(pchip->regmap, 0x0D, 0x00);
        if (ret < 0)
                goto err_i2c;

        /* sent power fault detection event to specific regulator */
        for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
                if ((flag0 & (0x4 << icnt))
                    && (pchip->irqmask & (0x04 << icnt))
                    && (pchip->rdev[icnt] != NULL)) {
                        regulator_notifier_call_chain(pchip->rdev[icnt],
                                                      LP8755_EVENT_PWR_FAULT,
                                                      NULL);
                }

        /* read flag1 register */
        ret = regmap_read(pchip->regmap, 0x0E, &flag1);
        if (ret < 0)
                goto err_i2c;
        /* clear flag register to pull up int. pin */
        ret = regmap_write(pchip->regmap, 0x0E, 0x00);
        if (ret < 0)
                goto err_i2c;

        /* send OCP event to all regulator devices */
        if ((flag1 & 0x01) && (pchip->irqmask & 0x01))
                for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
                        if (pchip->rdev[icnt] != NULL) {
                                regulator_notifier_call_chain(pchip->rdev[icnt],
                                                              LP8755_EVENT_OCP,
                                                              NULL);
                        }

        /* send OVP event to all regulator devices */
        if ((flag1 & 0x02) && (pchip->irqmask & 0x02))
                for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
                        if (pchip->rdev[icnt] != NULL) {
                                regulator_notifier_call_chain(pchip->rdev[icnt],
                                                              LP8755_EVENT_OVP,
                                                              NULL);
                        }
        return IRQ_HANDLED;

err_i2c:
        dev_err(pchip->dev, "i2c access error %s\n", __func__);
        return IRQ_NONE;
}

static int lp8755_int_config(struct lp8755_chip *pchip)
{
        int ret;
        unsigned int regval;

        if (pchip->irq == 0) {
                dev_warn(pchip->dev, "not use interrupt : %s\n", __func__);
                return 0;
        }

        ret = regmap_read(pchip->regmap, 0x0F, &regval);
        if (ret < 0) {
                dev_err(pchip->dev, "i2c access error %s\n", __func__);
                return ret;
        }

        pchip->irqmask = regval;
        return devm_request_threaded_irq(pchip->dev, pchip->irq, NULL,
                                         lp8755_irq_handler,
                                         IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
                                         "lp8755-irq", pchip);
}

static const struct regmap_config lp8755_regmap = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = LP8755_REG_MAX,
};

static int lp8755_probe(struct i2c_client *client)
{
        int ret, icnt;
        struct lp8755_chip *pchip;
        struct lp8755_platform_data *pdata = dev_get_platdata(&client->dev);

        if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
                dev_err(&client->dev, "i2c functionality check fail.\n");
                return -EOPNOTSUPP;
        }

        pchip = devm_kzalloc(&client->dev,
                             sizeof(struct lp8755_chip), GFP_KERNEL);
        if (!pchip)
                return -ENOMEM;

        pchip->dev = &client->dev;
        pchip->regmap = devm_regmap_init_i2c(client, &lp8755_regmap);
        if (IS_ERR(pchip->regmap)) {
                ret = PTR_ERR(pchip->regmap);
                dev_err(&client->dev, "fail to allocate regmap %d\n", ret);
                return ret;
        }
        i2c_set_clientdata(client, pchip);

        if (pdata != NULL) {
                pchip->pdata = pdata;
                pchip->mphase = pdata->mphase;
        } else {
                pchip->pdata = devm_kzalloc(pchip->dev,
                                            sizeof(struct lp8755_platform_data),
                                            GFP_KERNEL);
                if (!pchip->pdata)
                        return -ENOMEM;
                ret = lp8755_init_data(pchip);
                if (ret < 0) {
                        dev_err(&client->dev, "fail to initialize chip\n");
                        return ret;
                }
        }

        ret = lp8755_regulator_init(pchip);
        if (ret < 0) {
                dev_err(&client->dev, "fail to initialize regulators\n");
                goto err;
        }

        pchip->irq = client->irq;
        ret = lp8755_int_config(pchip);
        if (ret < 0) {
                dev_err(&client->dev, "fail to irq config\n");
                goto err;
        }

        return ret;

err:
        /* output disable */
        for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
                regmap_write(pchip->regmap, icnt, 0x00);

        return ret;
}

static void lp8755_remove(struct i2c_client *client)
{
        int icnt;
        struct lp8755_chip *pchip = i2c_get_clientdata(client);

        for (icnt = 0; icnt < LP8755_BUCK_MAX; icnt++)
                regmap_write(pchip->regmap, icnt, 0x00);
}

static const struct i2c_device_id lp8755_id[] = {
        { LP8755_NAME },
        {}
};

MODULE_DEVICE_TABLE(i2c, lp8755_id);

static struct i2c_driver lp8755_i2c_driver = {
        .driver = {
                   .name = LP8755_NAME,
                   .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                   },
        .probe = lp8755_probe,
        .remove = lp8755_remove,
        .id_table = lp8755_id,
};

static int __init lp8755_init(void)
{
        return i2c_add_driver(&lp8755_i2c_driver);
}

subsys_initcall(lp8755_init);

static void __exit lp8755_exit(void)
{
        i2c_del_driver(&lp8755_i2c_driver);
}

module_exit(lp8755_exit);

MODULE_DESCRIPTION("Texas Instruments lp8755 driver");
MODULE_AUTHOR("Daniel Jeong <daniel.jeong@ti.com>");
MODULE_LICENSE("GPL v2");