root/drivers/regulator/da9210-regulator.c
// SPDX-License-Identifier: GPL-2.0+
//
// da9210-regulator.c - Regulator device driver for DA9210
// Copyright (C) 2013  Dialog Semiconductor Ltd.

#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/of.h>
#include <linux/regulator/of_regulator.h>
#include <linux/regmap.h>

#include "da9210-regulator.h"

struct da9210 {
        struct regulator_dev *rdev;
        struct regmap *regmap;
};

static const struct regmap_config da9210_regmap_config = {
        .reg_bits = 8,
        .val_bits = 8,
};

static const struct regulator_ops da9210_buck_ops = {
        .enable = regulator_enable_regmap,
        .disable = regulator_disable_regmap,
        .is_enabled = regulator_is_enabled_regmap,
        .set_voltage_sel = regulator_set_voltage_sel_regmap,
        .get_voltage_sel = regulator_get_voltage_sel_regmap,
        .list_voltage = regulator_list_voltage_linear,
        .set_current_limit = regulator_set_current_limit_regmap,
        .get_current_limit = regulator_get_current_limit_regmap,
};

/* Default limits measured in millivolts and milliamps */
#define DA9210_MIN_MV           300
#define DA9210_MAX_MV           1570
#define DA9210_STEP_MV          10

/* Current limits for buck (uA) indices corresponds with register values */
static const unsigned int da9210_buck_limits[] = {
        1600000, 1800000, 2000000, 2200000, 2400000, 2600000, 2800000, 3000000,
        3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000, 4600000
};

static const struct regulator_desc da9210_reg = {
        .name = "DA9210",
        .id = 0,
        .ops = &da9210_buck_ops,
        .type = REGULATOR_VOLTAGE,
        .n_voltages = ((DA9210_MAX_MV - DA9210_MIN_MV) / DA9210_STEP_MV) + 1,
        .min_uV = (DA9210_MIN_MV * 1000),
        .uV_step = (DA9210_STEP_MV * 1000),
        .vsel_reg = DA9210_REG_VBUCK_A,
        .vsel_mask = DA9210_VBUCK_MASK,
        .enable_reg = DA9210_REG_BUCK_CONT,
        .enable_mask = DA9210_BUCK_EN,
        .owner = THIS_MODULE,
        .curr_table = da9210_buck_limits,
        .n_current_limits = ARRAY_SIZE(da9210_buck_limits),
        .csel_reg = DA9210_REG_BUCK_ILIM,
        .csel_mask = DA9210_BUCK_ILIM_MASK,
};

static irqreturn_t da9210_irq_handler(int irq, void *data)
{
        struct da9210 *chip = data;
        unsigned int val, handled = 0;
        int error, ret = IRQ_NONE;

        error = regmap_read(chip->regmap, DA9210_REG_EVENT_B, &val);
        if (error < 0)
                goto error_i2c;

        if (val & DA9210_E_OVCURR) {
                regulator_notifier_call_chain(chip->rdev,
                                              REGULATOR_EVENT_OVER_CURRENT,
                                              NULL);
                handled |= DA9210_E_OVCURR;
        }
        if (val & DA9210_E_NPWRGOOD) {
                regulator_notifier_call_chain(chip->rdev,
                                              REGULATOR_EVENT_UNDER_VOLTAGE,
                                              NULL);
                handled |= DA9210_E_NPWRGOOD;
        }
        if (val & (DA9210_E_TEMP_WARN | DA9210_E_TEMP_CRIT)) {
                regulator_notifier_call_chain(chip->rdev,
                                              REGULATOR_EVENT_OVER_TEMP, NULL);
                handled |= val & (DA9210_E_TEMP_WARN | DA9210_E_TEMP_CRIT);
        }
        if (val & DA9210_E_VMAX) {
                regulator_notifier_call_chain(chip->rdev,
                                              REGULATOR_EVENT_REGULATION_OUT,
                                              NULL);
                handled |= DA9210_E_VMAX;
        }

        if (handled) {
                /* Clear handled events */
                error = regmap_write(chip->regmap, DA9210_REG_EVENT_B, handled);
                if (error < 0)
                        goto error_i2c;

                ret = IRQ_HANDLED;
        }

        return ret;

error_i2c:
        dev_err(regmap_get_device(chip->regmap), "I2C error : %d\n", error);
        return ret;
}

/*
 * I2C driver interface functions
 */

static const struct of_device_id __maybe_unused da9210_dt_ids[] = {
        { .compatible = "dlg,da9210", },
        { }
};
MODULE_DEVICE_TABLE(of, da9210_dt_ids);

static int da9210_i2c_probe(struct i2c_client *i2c)
{
        struct da9210 *chip;
        struct device *dev = &i2c->dev;
        struct da9210_pdata *pdata = dev_get_platdata(dev);
        struct regulator_dev *rdev = NULL;
        struct regulator_config config = { };
        int error;

        chip = devm_kzalloc(&i2c->dev, sizeof(struct da9210), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        chip->regmap = devm_regmap_init_i2c(i2c, &da9210_regmap_config);
        if (IS_ERR(chip->regmap)) {
                error = PTR_ERR(chip->regmap);
                dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
                        error);
                return error;
        }

        config.dev = &i2c->dev;
        config.init_data = pdata ? &pdata->da9210_constraints :
                of_get_regulator_init_data(dev, dev->of_node, &da9210_reg);
        config.driver_data = chip;
        config.regmap = chip->regmap;
        config.of_node = dev->of_node;

        /* Mask all interrupt sources to deassert interrupt line */
        error = regmap_write(chip->regmap, DA9210_REG_MASK_A, ~0);
        if (!error)
                error = regmap_write(chip->regmap, DA9210_REG_MASK_B, ~0);
        if (error) {
                dev_err(&i2c->dev, "Failed to write to mask reg: %d\n", error);
                return error;
        }

        rdev = devm_regulator_register(&i2c->dev, &da9210_reg, &config);
        if (IS_ERR(rdev)) {
                dev_err(&i2c->dev, "Failed to register DA9210 regulator\n");
                return PTR_ERR(rdev);
        }

        chip->rdev = rdev;
        if (i2c->irq) {
                error = devm_request_threaded_irq(&i2c->dev, i2c->irq, NULL,
                                                  da9210_irq_handler,
                                                  IRQF_TRIGGER_LOW |
                                                  IRQF_ONESHOT | IRQF_SHARED,
                                                  "da9210", chip);
                if (error) {
                        dev_err(&i2c->dev, "Failed to request IRQ%u: %d\n",
                                i2c->irq, error);
                        return error;
                }

                error = regmap_update_bits(chip->regmap, DA9210_REG_MASK_B,
                                         DA9210_M_OVCURR | DA9210_M_NPWRGOOD |
                                         DA9210_M_TEMP_WARN |
                                         DA9210_M_TEMP_CRIT | DA9210_M_VMAX, 0);
                if (error < 0) {
                        dev_err(&i2c->dev, "Failed to update mask reg: %d\n",
                                error);
                        return error;
                }
        } else {
                dev_warn(&i2c->dev, "No IRQ configured\n");
        }

        i2c_set_clientdata(i2c, chip);

        return 0;
}

static const struct i2c_device_id da9210_i2c_id[] = {
        { "da9210" },
        {}
};

MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);

static struct i2c_driver da9210_regulator_driver = {
        .driver = {
                .name = "da9210",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
                .of_match_table = of_match_ptr(da9210_dt_ids),
        },
        .probe = da9210_i2c_probe,
        .id_table = da9210_i2c_id,
};

module_i2c_driver(da9210_regulator_driver);

MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
MODULE_LICENSE("GPL v2");