root/drivers/regulator/aw37503-regulator.c
// SPDX-License-Identifier: GPL-2.0
//
// AWINIC AW37503 Regulator Driver
//
// Copyright (C) 2023 awinic. All Rights Reserved
//
// Author: <like@awinic.com>

#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/regmap.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>

#define AW37503_REG_VPOS                0x00
#define AW37503_REG_VNEG                0x01
#define AW37503_REG_APPS                0x03
#define AW37503_REG_CONTROL             0x04
#define AW37503_REG_WPRTEN              0x21

#define AW37503_VOUT_MASK               0x1F
#define AW37503_VOUT_N_VOLTAGE          0x15
#define AW37503_VOUT_VMIN               4000000
#define AW37503_VOUT_VMAX               6000000
#define AW37503_VOUT_STEP               100000

#define AW37503_REG_APPS_DIS_VPOS       BIT(1)
#define AW37503_REG_APPS_DIS_VNEG       BIT(0)

#define AW37503_REGULATOR_ID_VPOS       0
#define AW37503_REGULATOR_ID_VNEG       1
#define AW37503_MAX_REGULATORS          2

struct aw37503_reg_pdata {
        struct gpio_desc *en_gpiod;
        int ena_gpio_state;
};

struct aw37503_regulator {
        struct device *dev;
        struct aw37503_reg_pdata reg_pdata[AW37503_MAX_REGULATORS];
};

static int aw37503_regulator_enable(struct regulator_dev *rdev)
{
        struct aw37503_regulator *chip = rdev_get_drvdata(rdev);
        int id = rdev_get_id(rdev);
        struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[id];
        int ret;

        if (!IS_ERR(rpdata->en_gpiod)) {
                gpiod_set_value_cansleep(rpdata->en_gpiod, 1);
                rpdata->ena_gpio_state = 1;
        }

        /* Hardware automatically enable discharge bit in enable */
        if (rdev->constraints->active_discharge ==
                        REGULATOR_ACTIVE_DISCHARGE_DISABLE) {
                ret = regulator_set_active_discharge_regmap(rdev, false);
                if (ret < 0) {
                        dev_err(chip->dev, "Failed to disable active discharge: %d\n",
                                ret);
                        return ret;
                }
        }

        return 0;
}

static int aw37503_regulator_disable(struct regulator_dev *rdev)
{
        struct aw37503_regulator *chip = rdev_get_drvdata(rdev);
        int id = rdev_get_id(rdev);
        struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[id];

        if (!IS_ERR(rpdata->en_gpiod)) {
                gpiod_set_value_cansleep(rpdata->en_gpiod, 0);
                rpdata->ena_gpio_state = 0;
        }

        return 0;
}

static int aw37503_regulator_is_enabled(struct regulator_dev *rdev)
{
        struct aw37503_regulator *chip = rdev_get_drvdata(rdev);
        int id = rdev_get_id(rdev);
        struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[id];

        if (!IS_ERR(rpdata->en_gpiod))
                return rpdata->ena_gpio_state;

        return 1;
}

static const struct regulator_ops aw37503_regulator_ops = {
        .enable = aw37503_regulator_enable,
        .disable = aw37503_regulator_disable,
        .is_enabled = aw37503_regulator_is_enabled,
        .list_voltage = regulator_list_voltage_linear,
        .map_voltage = regulator_map_voltage_linear,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .set_active_discharge = regulator_set_active_discharge_regmap,
};

static int aw37503_of_parse_cb(struct device_node *np,
                                const struct regulator_desc *desc,
                                struct regulator_config *config)
{
        struct aw37503_regulator *chip = config->driver_data;
        struct aw37503_reg_pdata *rpdata = &chip->reg_pdata[desc->id];
        int ret;

        rpdata->en_gpiod = devm_fwnode_gpiod_get(chip->dev, of_fwnode_handle(np),
                                                 "enable", GPIOD_OUT_LOW,
                                                 "enable");

        if (IS_ERR(rpdata->en_gpiod)) {
                ret = PTR_ERR(rpdata->en_gpiod);

                /* Ignore the error other than probe defer */
                if (ret == -EPROBE_DEFER)
                        return ret;
                return 0;
        }

        return 0;
}

#define AW37503_REGULATOR_DESC(_id, _name)              \
        [AW37503_REGULATOR_ID_##_id] = {                \
                .name = "aw37503-"#_name,               \
                .supply_name = "vin",                   \
                .id = AW37503_REGULATOR_ID_##_id,       \
                .of_match = of_match_ptr(#_name),       \
                .of_parse_cb = aw37503_of_parse_cb,     \
                .ops = &aw37503_regulator_ops,          \
                .n_voltages = AW37503_VOUT_N_VOLTAGE,   \
                .min_uV = AW37503_VOUT_VMIN,            \
                .uV_step = AW37503_VOUT_STEP,           \
                .enable_time = 500,                     \
                .vsel_mask = AW37503_VOUT_MASK, \
                .vsel_reg = AW37503_REG_##_id,          \
                .active_discharge_off = 0,                      \
                .active_discharge_on = AW37503_REG_APPS_DIS_##_id, \
                .active_discharge_mask = AW37503_REG_APPS_DIS_##_id, \
                .active_discharge_reg = AW37503_REG_APPS, \
                .type = REGULATOR_VOLTAGE,              \
                .owner = THIS_MODULE,                   \
        }

static const struct regulator_desc aw_regs_desc[AW37503_MAX_REGULATORS] = {
        AW37503_REGULATOR_DESC(VPOS, outp),
        AW37503_REGULATOR_DESC(VNEG, outn),
};

static const struct regmap_range aw37503_no_reg_ranges[] = {
        regmap_reg_range(AW37503_REG_CONTROL + 1,
                         AW37503_REG_WPRTEN - 1),
};

static const struct regmap_access_table aw37503_no_reg_table = {
        .no_ranges = aw37503_no_reg_ranges,
        .n_no_ranges = ARRAY_SIZE(aw37503_no_reg_ranges),
};

static const struct regmap_config aw37503_regmap_config = {
        .reg_bits       = 8,
        .val_bits       = 8,
        .max_register   = AW37503_REG_WPRTEN,
        .rd_table       = &aw37503_no_reg_table,
        .wr_table       = &aw37503_no_reg_table,
};

static int aw37503_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct aw37503_regulator *chip;
        struct regulator_dev *rdev;
        struct regmap *regmap;
        struct regulator_config config = { };
        int id;

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

        regmap = devm_regmap_init_i2c(client, &aw37503_regmap_config);
        if (IS_ERR(regmap))
                return dev_err_probe(dev, PTR_ERR(regmap),
                                     "Failed to init regmap\n");

        i2c_set_clientdata(client, chip);
        chip->dev = dev;

        config.regmap = regmap;
        config.dev = dev;
        config.driver_data = chip;

        for (id = 0; id < AW37503_MAX_REGULATORS; ++id) {
                rdev = devm_regulator_register(dev, &aw_regs_desc[id],
                                               &config);
                if (IS_ERR(rdev))
                        return dev_err_probe(dev, PTR_ERR(rdev),
                                             "Failed to register regulator %s\n",
                                             aw_regs_desc[id].name);
        }
        return 0;
}

static const struct i2c_device_id aw37503_id[] = {
        {.name = "aw37503",},
        {},
};
MODULE_DEVICE_TABLE(i2c, aw37503_id);

static const struct of_device_id aw37503_of_match[] = {
        {.compatible = "awinic,aw37503",},
        { /* Sentinel */ },
};

MODULE_DEVICE_TABLE(of, aw37503_of_match);

static struct i2c_driver aw37503_i2c_driver = {
        .driver = {
                .name = "aw37503",
                .of_match_table = aw37503_of_match,
        },
        .probe = aw37503_probe,
        .id_table = aw37503_id,
};

module_i2c_driver(aw37503_i2c_driver);

MODULE_DESCRIPTION("aw37503 regulator driver");
MODULE_AUTHOR("Alec Li <like@awinic.com>");
MODULE_LICENSE("GPL");