root/drivers/regulator/tps51632-regulator.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * tps51632-regulator.c -- TI TPS51632
 *
 * Regulator driver for TPS51632 3-2-1 Phase D-Cap Step Down Driverless
 * Controller with serial VID control and DVFS.
 *
 * Copyright (c) 2012, NVIDIA Corporation.
 *
 * Author: Laxman Dewangan <ldewangan@nvidia.com>
 */

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/init.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/driver.h>
#include <linux/regulator/machine.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regulator/tps51632-regulator.h>
#include <linux/slab.h>

/* Register definitions */
#define TPS51632_VOLTAGE_SELECT_REG             0x0
#define TPS51632_VOLTAGE_BASE_REG               0x1
#define TPS51632_OFFSET_REG                     0x2
#define TPS51632_IMON_REG                       0x3
#define TPS51632_VMAX_REG                       0x4
#define TPS51632_DVFS_CONTROL_REG               0x5
#define TPS51632_POWER_STATE_REG                0x6
#define TPS51632_SLEW_REGS                      0x7
#define TPS51632_FAULT_REG                      0x14

#define TPS51632_MAX_REG                        0x15

#define TPS51632_VOUT_MASK                      0x7F
#define TPS51632_VOUT_OFFSET_MASK               0x1F
#define TPS51632_VMAX_MASK                      0x7F
#define TPS51632_VMAX_LOCK                      0x80

/* TPS51632_DVFS_CONTROL_REG */
#define TPS51632_DVFS_PWMEN                     0x1
#define TPS51632_DVFS_STEP_20                   0x2
#define TPS51632_DVFS_VMAX_PG                   0x4
#define TPS51632_DVFS_PWMRST                    0x8
#define TPS51632_DVFS_OCA_EN                    0x10
#define TPS51632_DVFS_FCCM                      0x20

/* TPS51632_POWER_STATE_REG */
#define TPS51632_POWER_STATE_MASK               0x03
#define TPS51632_POWER_STATE_MULTI_PHASE_CCM    0x0
#define TPS51632_POWER_STATE_SINGLE_PHASE_CCM   0x1
#define TPS51632_POWER_STATE_SINGLE_PHASE_DCM   0x2

#define TPS51632_MIN_VOLTAGE                    500000
#define TPS51632_MAX_VOLTAGE                    1520000
#define TPS51632_VOLTAGE_STEP_10mV              10000
#define TPS51632_VOLTAGE_STEP_20mV              20000
#define TPS51632_MAX_VSEL                       0x7F
#define TPS51632_MIN_VSEL                       0x19
#define TPS51632_DEFAULT_RAMP_DELAY             6000
#define TPS51632_VOLT_VSEL(uV)                                  \
                (DIV_ROUND_UP(uV - TPS51632_MIN_VOLTAGE,        \
                        TPS51632_VOLTAGE_STEP_10mV) +           \
                        TPS51632_MIN_VSEL)

/* TPS51632 chip information */
struct tps51632_chip {
        struct device *dev;
        struct regulator_desc desc;
        struct regulator_dev *rdev;
        struct regmap *regmap;
};

static int tps51632_dcdc_set_ramp_delay(struct regulator_dev *rdev,
                int ramp_delay)
{
        struct tps51632_chip *tps = rdev_get_drvdata(rdev);
        int bit;
        int ret;

        if (ramp_delay == 0)
                bit = 0;
        else
                bit = DIV_ROUND_UP(ramp_delay, 6000) - 1;

        ret = regmap_write(tps->regmap, TPS51632_SLEW_REGS, BIT(bit));
        if (ret < 0)
                dev_err(tps->dev, "SLEW reg write failed, err %d\n", ret);
        return ret;
}

static const struct regulator_ops tps51632_dcdc_ops = {
        .get_voltage_sel        = regulator_get_voltage_sel_regmap,
        .set_voltage_sel        = regulator_set_voltage_sel_regmap,
        .list_voltage           = regulator_list_voltage_linear,
        .set_voltage_time_sel   = regulator_set_voltage_time_sel,
        .set_ramp_delay         = tps51632_dcdc_set_ramp_delay,
};

static int tps51632_init_dcdc(struct tps51632_chip *tps,
                struct tps51632_regulator_platform_data *pdata)
{
        int ret;
        uint8_t control = 0;
        int vsel;

        if (!pdata->enable_pwm_dvfs)
                goto skip_pwm_config;

        control |= TPS51632_DVFS_PWMEN;
        vsel = TPS51632_VOLT_VSEL(pdata->base_voltage_uV);
        ret = regmap_write(tps->regmap, TPS51632_VOLTAGE_BASE_REG, vsel);
        if (ret < 0) {
                dev_err(tps->dev, "BASE reg write failed, err %d\n", ret);
                return ret;
        }

        if (pdata->dvfs_step_20mV)
                control |= TPS51632_DVFS_STEP_20;

        if (pdata->max_voltage_uV) {
                unsigned int vmax;
                /**
                 * TPS51632 hw behavior: VMAX register can be write only
                 * once as it get locked after first write. The lock get
                 * reset only when device is power-reset.
                 * Write register only when lock bit is not enabled.
                 */
                ret = regmap_read(tps->regmap, TPS51632_VMAX_REG, &vmax);
                if (ret < 0) {
                        dev_err(tps->dev, "VMAX read failed, err %d\n", ret);
                        return ret;
                }
                if (!(vmax & TPS51632_VMAX_LOCK)) {
                        vsel = TPS51632_VOLT_VSEL(pdata->max_voltage_uV);
                        ret = regmap_write(tps->regmap, TPS51632_VMAX_REG,
                                        vsel);
                        if (ret < 0) {
                                dev_err(tps->dev,
                                        "VMAX write failed, err %d\n", ret);
                                return ret;
                        }
                }
        }

skip_pwm_config:
        ret = regmap_write(tps->regmap, TPS51632_DVFS_CONTROL_REG, control);
        if (ret < 0)
                dev_err(tps->dev, "DVFS reg write failed, err %d\n", ret);
        return ret;
}

static bool is_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case TPS51632_OFFSET_REG:
        case TPS51632_FAULT_REG:
        case TPS51632_IMON_REG:
                return true;
        default:
                return false;
        }
}

static bool is_read_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case 0x08 ... 0x0F:
                return false;
        default:
                return true;
        }
}

static bool is_write_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case TPS51632_VOLTAGE_SELECT_REG:
        case TPS51632_VOLTAGE_BASE_REG:
        case TPS51632_VMAX_REG:
        case TPS51632_DVFS_CONTROL_REG:
        case TPS51632_POWER_STATE_REG:
        case TPS51632_SLEW_REGS:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config tps51632_regmap_config = {
        .reg_bits               = 8,
        .val_bits               = 8,
        .writeable_reg          = is_write_reg,
        .readable_reg           = is_read_reg,
        .volatile_reg           = is_volatile_reg,
        .max_register           = TPS51632_MAX_REG - 1,
        .cache_type             = REGCACHE_MAPLE,
};

#if defined(CONFIG_OF)
static const struct of_device_id tps51632_of_match[] = {
        { .compatible = "ti,tps51632",},
        {},
};
MODULE_DEVICE_TABLE(of, tps51632_of_match);

static struct tps51632_regulator_platform_data *
        of_get_tps51632_platform_data(struct device *dev,
                                      const struct regulator_desc *desc)
{
        struct tps51632_regulator_platform_data *pdata;
        struct device_node *np = dev->of_node;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return NULL;

        pdata->reg_init_data = of_get_regulator_init_data(dev, dev->of_node,
                                                          desc);
        if (!pdata->reg_init_data) {
                dev_err(dev, "Not able to get OF regulator init data\n");
                return NULL;
        }

        pdata->enable_pwm_dvfs =
                        of_property_read_bool(np, "ti,enable-pwm-dvfs");
        pdata->dvfs_step_20mV = of_property_read_bool(np, "ti,dvfs-step-20mV");

        pdata->base_voltage_uV = pdata->reg_init_data->constraints.min_uV ? :
                                        TPS51632_MIN_VOLTAGE;
        pdata->max_voltage_uV = pdata->reg_init_data->constraints.max_uV ? :
                                        TPS51632_MAX_VOLTAGE;
        return pdata;
}
#else
static struct tps51632_regulator_platform_data *
        of_get_tps51632_platform_data(struct device *dev,
                                      const struct regulator_desc *desc)
{
        return NULL;
}
#endif

static int tps51632_probe(struct i2c_client *client)
{
        struct tps51632_regulator_platform_data *pdata;
        struct regulator_dev *rdev;
        struct tps51632_chip *tps;
        int ret;
        struct regulator_config config = { };

        tps = devm_kzalloc(&client->dev, sizeof(*tps), GFP_KERNEL);
        if (!tps)
                return -ENOMEM;

        tps->dev = &client->dev;
        tps->desc.name = client->name;
        tps->desc.id = 0;
        tps->desc.ramp_delay = TPS51632_DEFAULT_RAMP_DELAY;
        tps->desc.min_uV = TPS51632_MIN_VOLTAGE;
        tps->desc.uV_step = TPS51632_VOLTAGE_STEP_10mV;
        tps->desc.linear_min_sel = TPS51632_MIN_VSEL;
        tps->desc.n_voltages = TPS51632_MAX_VSEL + 1;
        tps->desc.ops = &tps51632_dcdc_ops;
        tps->desc.type = REGULATOR_VOLTAGE;
        tps->desc.owner = THIS_MODULE;

        pdata = dev_get_platdata(&client->dev);
        if (!pdata && client->dev.of_node)
                pdata = of_get_tps51632_platform_data(&client->dev, &tps->desc);
        if (!pdata) {
                dev_err(&client->dev, "No Platform data\n");
                return -EINVAL;
        }

        if (pdata->enable_pwm_dvfs) {
                if ((pdata->base_voltage_uV < TPS51632_MIN_VOLTAGE) ||
                    (pdata->base_voltage_uV > TPS51632_MAX_VOLTAGE)) {
                        dev_err(&client->dev, "Invalid base_voltage_uV setting\n");
                        return -EINVAL;
                }

                if ((pdata->max_voltage_uV) &&
                    ((pdata->max_voltage_uV < TPS51632_MIN_VOLTAGE) ||
                     (pdata->max_voltage_uV > TPS51632_MAX_VOLTAGE))) {
                        dev_err(&client->dev, "Invalid max_voltage_uV setting\n");
                        return -EINVAL;
                }
        }

        if (pdata->enable_pwm_dvfs)
                tps->desc.vsel_reg = TPS51632_VOLTAGE_BASE_REG;
        else
                tps->desc.vsel_reg = TPS51632_VOLTAGE_SELECT_REG;
        tps->desc.vsel_mask = TPS51632_VOUT_MASK;

        tps->regmap = devm_regmap_init_i2c(client, &tps51632_regmap_config);
        if (IS_ERR(tps->regmap)) {
                ret = PTR_ERR(tps->regmap);
                dev_err(&client->dev, "regmap init failed, err %d\n", ret);
                return ret;
        }
        i2c_set_clientdata(client, tps);

        ret = tps51632_init_dcdc(tps, pdata);
        if (ret < 0) {
                dev_err(tps->dev, "Init failed, err = %d\n", ret);
                return ret;
        }

        /* Register the regulators */
        config.dev = &client->dev;
        config.init_data = pdata->reg_init_data;
        config.driver_data = tps;
        config.regmap = tps->regmap;
        config.of_node = client->dev.of_node;

        rdev = devm_regulator_register(&client->dev, &tps->desc, &config);
        if (IS_ERR(rdev)) {
                dev_err(tps->dev, "regulator register failed\n");
                return PTR_ERR(rdev);
        }

        tps->rdev = rdev;
        return 0;
}

static const struct i2c_device_id tps51632_id[] = {
        {.name = "tps51632",},
        {},
};

MODULE_DEVICE_TABLE(i2c, tps51632_id);

static struct i2c_driver tps51632_i2c_driver = {
        .driver = {
                .name = "tps51632",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = of_match_ptr(tps51632_of_match),
        },
        .probe = tps51632_probe,
        .id_table = tps51632_id,
};

static int __init tps51632_init(void)
{
        return i2c_add_driver(&tps51632_i2c_driver);
}
subsys_initcall(tps51632_init);

static void __exit tps51632_cleanup(void)
{
        i2c_del_driver(&tps51632_i2c_driver);
}
module_exit(tps51632_cleanup);

MODULE_AUTHOR("Laxman Dewangan <ldewangan@nvidia.com>");
MODULE_DESCRIPTION("TPS51632 voltage regulator driver");
MODULE_LICENSE("GPL v2");