root/drivers/regulator/mpq7920.c
// SPDX-License-Identifier: GPL-2.0+
//
// mpq7920.c  - regulator driver for mps mpq7920
//
// Copyright 2019 Monolithic Power Systems, Inc
//
// Author: Saravanan Sekar <sravanhome@gmail.com>

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>
#include <linux/i2c.h>
#include <linux/regmap.h>
#include "mpq7920.h"

#define MPQ7920_BUCK_VOLT_RANGE \
        ((MPQ7920_VOLT_MAX - MPQ7920_BUCK_VOLT_MIN)/MPQ7920_VOLT_STEP + 1)
#define MPQ7920_LDO_VOLT_RANGE \
        ((MPQ7920_VOLT_MAX - MPQ7920_LDO_VOLT_MIN)/MPQ7920_VOLT_STEP + 1)

#define MPQ7920BUCK(_name, _id, _ilim)                                  \
        [MPQ7920_BUCK ## _id] = {                                       \
                .id = MPQ7920_BUCK ## _id,                              \
                .name = _name,                                          \
                .of_match = _name,                                      \
                .regulators_node = "regulators",                        \
                .of_parse_cb = mpq7920_parse_cb,                        \
                .ops = &mpq7920_buck_ops,                               \
                .min_uV = MPQ7920_BUCK_VOLT_MIN,                        \
                .uV_step = MPQ7920_VOLT_STEP,                           \
                .n_voltages = MPQ7920_BUCK_VOLT_RANGE,                  \
                .curr_table = _ilim,                                    \
                .n_current_limits = ARRAY_SIZE(_ilim),                  \
                .csel_reg = MPQ7920_BUCK ##_id## _REG_C,                \
                .csel_mask = MPQ7920_MASK_BUCK_ILIM,                    \
                .enable_reg = MPQ7920_REG_REGULATOR_EN,                 \
                .enable_mask = BIT(MPQ7920_REGULATOR_EN_OFFSET -        \
                                         MPQ7920_BUCK ## _id),          \
                .vsel_reg = MPQ7920_BUCK ##_id## _REG_A,                \
                .vsel_mask = MPQ7920_MASK_VREF,                         \
                .active_discharge_on    = MPQ7920_DISCHARGE_ON,         \
                .active_discharge_reg   = MPQ7920_BUCK ##_id## _REG_B,  \
                .active_discharge_mask  = MPQ7920_MASK_DISCHARGE,       \
                .soft_start_reg         = MPQ7920_BUCK ##_id## _REG_C,  \
                .soft_start_mask        = MPQ7920_MASK_SOFTSTART,       \
                .owner                  = THIS_MODULE,                  \
        }

#define MPQ7920LDO(_name, _id, _ops, _ilim, _ilim_sz, _creg, _cmask)    \
        [MPQ7920_LDO ## _id] = {                                        \
                .id = MPQ7920_LDO ## _id,                               \
                .name = _name,                                          \
                .of_match = _name,                                      \
                .regulators_node = "regulators",                        \
                .ops = _ops,                                            \
                .min_uV = MPQ7920_LDO_VOLT_MIN,                         \
                .uV_step = MPQ7920_VOLT_STEP,                           \
                .n_voltages = MPQ7920_LDO_VOLT_RANGE,                   \
                .vsel_reg = MPQ7920_LDO ##_id## _REG_A,                 \
                .vsel_mask = MPQ7920_MASK_VREF,                         \
                .curr_table = _ilim,                                    \
                .n_current_limits = _ilim_sz,                           \
                .csel_reg = _creg,                                      \
                .csel_mask = _cmask,                                    \
                .enable_reg = (_id == 1) ? 0 : MPQ7920_REG_REGULATOR_EN,\
                .enable_mask = BIT(MPQ7920_REGULATOR_EN_OFFSET -        \
                                        MPQ7920_LDO ##_id + 1),         \
                .active_discharge_on    = MPQ7920_DISCHARGE_ON,         \
                .active_discharge_mask  = MPQ7920_MASK_DISCHARGE,       \
                .active_discharge_reg   = MPQ7920_LDO ##_id## _REG_B,   \
                .type                   = REGULATOR_VOLTAGE,            \
                .owner                  = THIS_MODULE,                  \
        }

enum mpq7920_regulators {
        MPQ7920_BUCK1,
        MPQ7920_BUCK2,
        MPQ7920_BUCK3,
        MPQ7920_BUCK4,
        MPQ7920_LDO1, /* LDORTC */
        MPQ7920_LDO2,
        MPQ7920_LDO3,
        MPQ7920_LDO4,
        MPQ7920_LDO5,
        MPQ7920_MAX_REGULATORS,
};

struct mpq7920_regulator_info {
        struct regmap *regmap;
        struct regulator_desc *rdesc;
};

static const struct regmap_config mpq7920_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
        .max_register = 0x25,
};

/* Current limits array (in uA)
 * ILIM1 & ILIM3
 */
static const unsigned int mpq7920_I_limits1[] = {
        4600000, 6600000, 7600000, 9300000
};

/* ILIM2 & ILIM4 */
static const unsigned int mpq7920_I_limits2[] = {
        2700000, 3900000, 5100000, 6100000
};

/* LDO4 & LDO5 */
static const unsigned int mpq7920_I_limits3[] = {
        300000, 700000
};

static int mpq7920_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay);
static int mpq7920_parse_cb(struct device_node *np,
                                const struct regulator_desc *rdesc,
                                struct regulator_config *config);

/* RTCLDO not controllable, always ON */
static const struct regulator_ops mpq7920_ldortc_ops = {
        .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,
};

static const struct regulator_ops mpq7920_ldo_wo_current_ops = {
        .enable                 = regulator_enable_regmap,
        .disable                = regulator_disable_regmap,
        .is_enabled             = regulator_is_enabled_regmap,
        .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 const struct regulator_ops mpq7920_ldo_ops = {
        .enable                 = regulator_enable_regmap,
        .disable                = regulator_disable_regmap,
        .is_enabled             = regulator_is_enabled_regmap,
        .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,
        .get_current_limit      = regulator_get_current_limit_regmap,
        .set_current_limit      = regulator_set_current_limit_regmap,
};

static const struct regulator_ops mpq7920_buck_ops = {
        .enable                 = regulator_enable_regmap,
        .disable                = regulator_disable_regmap,
        .is_enabled             = regulator_is_enabled_regmap,
        .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,
        .set_soft_start         = regulator_set_soft_start_regmap,
        .set_ramp_delay         = mpq7920_set_ramp_delay,
};

static struct regulator_desc mpq7920_regulators_desc[MPQ7920_MAX_REGULATORS] = {
        MPQ7920BUCK("buck1", 1, mpq7920_I_limits1),
        MPQ7920BUCK("buck2", 2, mpq7920_I_limits2),
        MPQ7920BUCK("buck3", 3, mpq7920_I_limits1),
        MPQ7920BUCK("buck4", 4, mpq7920_I_limits2),
        MPQ7920LDO("ldortc", 1, &mpq7920_ldortc_ops, NULL, 0, 0, 0),
        MPQ7920LDO("ldo2", 2, &mpq7920_ldo_wo_current_ops, NULL, 0, 0, 0),
        MPQ7920LDO("ldo3", 3, &mpq7920_ldo_wo_current_ops, NULL, 0, 0, 0),
        MPQ7920LDO("ldo4", 4, &mpq7920_ldo_ops, mpq7920_I_limits3,
                        ARRAY_SIZE(mpq7920_I_limits3), MPQ7920_LDO4_REG_B,
                        MPQ7920_MASK_LDO_ILIM),
        MPQ7920LDO("ldo5", 5, &mpq7920_ldo_ops, mpq7920_I_limits3,
                        ARRAY_SIZE(mpq7920_I_limits3), MPQ7920_LDO5_REG_B,
                        MPQ7920_MASK_LDO_ILIM),
};

/*
 * DVS ramp rate BUCK1 to BUCK4
 * 00-01: Reserved
 * 10: 8mV/us
 * 11: 4mV/us
 */
static int mpq7920_set_ramp_delay(struct regulator_dev *rdev, int ramp_delay)
{
        unsigned int ramp_val;

        if (ramp_delay > 8000 || ramp_delay < 0)
                return -EINVAL;

        if (ramp_delay <= 4000)
                ramp_val = 3;
        else
                ramp_val = 2;

        return regmap_update_bits(rdev->regmap, MPQ7920_REG_CTL0,
                                  MPQ7920_MASK_DVS_SLEWRATE, ramp_val << 6);
}

static int mpq7920_parse_cb(struct device_node *np,
                                const struct regulator_desc *desc,
                                struct regulator_config *config)
{
        uint8_t val;
        int ret;
        struct mpq7920_regulator_info *info = config->driver_data;
        struct regulator_desc *rdesc = &info->rdesc[desc->id];

        if (of_property_read_bool(np, "mps,buck-ovp-disable")) {
                regmap_update_bits(config->regmap,
                                MPQ7920_BUCK1_REG_B + (rdesc->id * 4),
                                MPQ7920_MASK_OVP, MPQ7920_OVP_DISABLE);
        }

        ret = of_property_read_u8(np, "mps,buck-phase-delay", &val);
        if (!ret) {
                regmap_update_bits(config->regmap,
                                MPQ7920_BUCK1_REG_C + (rdesc->id * 4),
                                MPQ7920_MASK_BUCK_PHASE_DEALY,
                                (val & 3) << 4);
        }

        ret = of_property_read_u8(np, "mps,buck-softstart", &val);
        if (!ret)
                rdesc->soft_start_val_on = (val & 3) << 2;

        return 0;
}

static void mpq7920_parse_dt(struct device *dev,
                 struct mpq7920_regulator_info *info)
{
        int ret;
        struct device_node *np = dev->of_node;
        uint8_t freq;

        np = of_get_child_by_name(np, "regulators");
        if (!np) {
                dev_err(dev, "missing 'regulators' subnode in DT\n");
                return;
        }

        ret = of_property_read_u8(np, "mps,switch-freq", &freq);
        if (!ret) {
                regmap_update_bits(info->regmap, MPQ7920_REG_CTL0,
                                        MPQ7920_MASK_SWITCH_FREQ,
                                        (freq & 3) << 4);
        }

        of_node_put(np);
}

static int mpq7920_i2c_probe(struct i2c_client *client)
{
        struct device *dev = &client->dev;
        struct mpq7920_regulator_info *info;
        struct regulator_config config = { NULL, };
        struct regulator_dev *rdev;
        struct regmap *regmap;
        int i;

        info = devm_kzalloc(dev, sizeof(struct mpq7920_regulator_info),
                                GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        info->rdesc = mpq7920_regulators_desc;
        regmap = devm_regmap_init_i2c(client, &mpq7920_regmap_config);
        if (IS_ERR(regmap)) {
                dev_err(dev, "Failed to allocate regmap!\n");
                return PTR_ERR(regmap);
        }

        i2c_set_clientdata(client, info);
        info->regmap = regmap;
        if (client->dev.of_node)
                mpq7920_parse_dt(&client->dev, info);

        config.dev = dev;
        config.regmap = regmap;
        config.driver_data = info;

        for (i = 0; i < MPQ7920_MAX_REGULATORS; i++) {
                rdev = devm_regulator_register(dev,
                                               &mpq7920_regulators_desc[i],
                                               &config);
                if (IS_ERR(rdev)) {
                        dev_err(dev, "Failed to register regulator!\n");
                        return PTR_ERR(rdev);
                }
        }

        return 0;
}

static const struct of_device_id mpq7920_of_match[] = {
        { .compatible = "mps,mpq7920"},
        {},
};
MODULE_DEVICE_TABLE(of, mpq7920_of_match);

static const struct i2c_device_id mpq7920_id[] = {
        { "mpq7920", },
        { },
};
MODULE_DEVICE_TABLE(i2c, mpq7920_id);

static struct i2c_driver mpq7920_regulator_driver = {
        .driver = {
                .name = "mpq7920",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = mpq7920_of_match,
        },
        .probe = mpq7920_i2c_probe,
        .id_table = mpq7920_id,
};
module_i2c_driver(mpq7920_regulator_driver);

MODULE_AUTHOR("Saravanan Sekar <sravanhome@gmail.com>");
MODULE_DESCRIPTION("MPQ7920 PMIC regulator driver");
MODULE_LICENSE("GPL");