root/drivers/mfd/rn5t618.c
// SPDX-License-Identifier: GPL-2.0-only
/*
 * MFD core driver for Ricoh RN5T618 PMIC
 *
 * Copyright (C) 2014 Beniamino Galvani <b.galvani@gmail.com>
 * Copyright (C) 2016 Toradex AG
 */

#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/irq.h>
#include <linux/mfd/core.h>
#include <linux/mfd/rn5t618.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/regmap.h>

static const struct mfd_cell rn5t618_cells[] = {
        { .name = "rn5t618-regulator" },
        { .name = "rn5t618-wdt" },
};

static const struct mfd_cell rc5t619_cells[] = {
        { .name = "rn5t618-adc" },
        { .name = "rn5t618-power" },
        { .name = "rn5t618-regulator" },
        { .name = "rc5t619-rtc" },
        { .name = "rn5t618-wdt" },
};

static bool rn5t618_volatile_reg(struct device *dev, unsigned int reg)
{
        switch (reg) {
        case RN5T618_WATCHDOGCNT:
        case RN5T618_DCIRQ:
        case RN5T618_ILIMDATAH ... RN5T618_AIN0DATAL:
        case RN5T618_ADCCNT3:
        case RN5T618_IR_ADC1 ... RN5T618_IR_ADC3:
        case RN5T618_IR_GPR:
        case RN5T618_IR_GPF:
        case RN5T618_MON_IOIN:
        case RN5T618_INTMON:
        case RN5T618_RTC_CTRL1 ... RN5T618_RTC_CTRL2:
        case RN5T618_RTC_SECONDS ... RN5T618_RTC_YEAR:
        case RN5T618_CHGCTL1:
        case RN5T618_REGISET1 ... RN5T618_REGISET2:
        case RN5T618_CHGSTATE:
        case RN5T618_CHGCTRL_IRR ... RN5T618_CHGERR_MONI:
        case RN5T618_GCHGDET:
        case RN5T618_CONTROL ... RN5T618_CC_AVEREG0:
                return true;
        default:
                return false;
        }
}

static const struct regmap_config rn5t618_regmap_config = {
        .reg_bits       = 8,
        .val_bits       = 8,
        .volatile_reg   = rn5t618_volatile_reg,
        .max_register   = RN5T618_MAX_REG,
        .cache_type     = REGCACHE_MAPLE,
};

static const struct regmap_irq rc5t619_irqs[] = {
        REGMAP_IRQ_REG(RN5T618_IRQ_SYS, 0, BIT(0)),
        REGMAP_IRQ_REG(RN5T618_IRQ_DCDC, 0, BIT(1)),
        REGMAP_IRQ_REG(RN5T618_IRQ_RTC, 0, BIT(2)),
        REGMAP_IRQ_REG(RN5T618_IRQ_ADC, 0, BIT(3)),
        REGMAP_IRQ_REG(RN5T618_IRQ_GPIO, 0, BIT(4)),
        REGMAP_IRQ_REG(RN5T618_IRQ_CHG, 0, BIT(6)),
};

static const struct regmap_irq_chip rc5t619_irq_chip = {
        .name = "rc5t619",
        .irqs = rc5t619_irqs,
        .num_irqs = ARRAY_SIZE(rc5t619_irqs),
        .num_regs = 1,
        .status_base = RN5T618_INTMON,
        .unmask_base = RN5T618_INTEN,
};

static struct i2c_client *rn5t618_pm_power_off;
static struct notifier_block rn5t618_restart_handler;

static int rn5t618_irq_init(struct rn5t618 *rn5t618)
{
        const struct regmap_irq_chip *irq_chip = NULL;
        int ret;

        if (!rn5t618->irq)
                return 0;

        switch (rn5t618->variant) {
        case RC5T619:
                irq_chip = &rc5t619_irq_chip;
                break;
        default:
                dev_err(rn5t618->dev, "Currently no IRQ support for variant %d\n",
                        (int)rn5t618->variant);
                return -ENOENT;
        }

        ret = devm_regmap_add_irq_chip(rn5t618->dev, rn5t618->regmap,
                                       rn5t618->irq,
                                       IRQF_TRIGGER_LOW | IRQF_ONESHOT,
                                       0, irq_chip, &rn5t618->irq_data);
        if (ret)
                dev_err(rn5t618->dev, "Failed to register IRQ chip\n");

        return ret;
}

static void rn5t618_trigger_poweroff_sequence(bool repower)
{
        int ret;

        /* disable automatic repower-on */
        ret = i2c_smbus_read_byte_data(rn5t618_pm_power_off, RN5T618_REPCNT);
        if (ret < 0)
                goto err;

        ret &= ~RN5T618_REPCNT_REPWRON;
        if (repower)
                ret |= RN5T618_REPCNT_REPWRON;

        ret = i2c_smbus_write_byte_data(rn5t618_pm_power_off,
                                        RN5T618_REPCNT, (u8)ret);
        if (ret < 0)
                goto err;

        /* start power-off sequence */
        ret = i2c_smbus_read_byte_data(rn5t618_pm_power_off, RN5T618_SLPCNT);
        if (ret < 0)
                goto err;

        ret |= RN5T618_SLPCNT_SWPWROFF;

        ret = i2c_smbus_write_byte_data(rn5t618_pm_power_off,
                                        RN5T618_SLPCNT, (u8)ret);
        if (ret < 0)
                goto err;

        return;

err:
        dev_alert(&rn5t618_pm_power_off->dev, "Failed to shutdown (err = %d)\n", ret);
}

static void rn5t618_power_off(void)
{
        rn5t618_trigger_poweroff_sequence(false);
}

static int rn5t618_restart(struct notifier_block *this,
                            unsigned long mode, void *cmd)
{
        rn5t618_trigger_poweroff_sequence(true);

        /*
         * Re-power factor detection on PMIC side is not instant. 1ms
         * proved to be enough time until reset takes effect.
         */
        mdelay(1);

        return NOTIFY_DONE;
}

static const struct of_device_id rn5t618_of_match[] = {
        { .compatible = "ricoh,rn5t567", .data = (void *)RN5T567 },
        { .compatible = "ricoh,rn5t618", .data = (void *)RN5T618 },
        { .compatible = "ricoh,rc5t619", .data = (void *)RC5T619 },
        { }
};
MODULE_DEVICE_TABLE(of, rn5t618_of_match);

static int rn5t618_i2c_probe(struct i2c_client *i2c)
{
        struct rn5t618 *priv;
        int ret;

        priv = devm_kzalloc(&i2c->dev, sizeof(*priv), GFP_KERNEL);
        if (!priv)
                return -ENOMEM;

        i2c_set_clientdata(i2c, priv);
        priv->variant = (long)i2c_get_match_data(i2c);
        priv->irq = i2c->irq;
        priv->dev = &i2c->dev;

        priv->regmap = devm_regmap_init_i2c(i2c, &rn5t618_regmap_config);
        if (IS_ERR(priv->regmap)) {
                ret = PTR_ERR(priv->regmap);
                dev_err(&i2c->dev, "regmap init failed: %d\n", ret);
                return ret;
        }

        if (priv->variant == RC5T619)
                ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_NONE,
                                           rc5t619_cells,
                                           ARRAY_SIZE(rc5t619_cells),
                                           NULL, 0, NULL);
        else
                ret = devm_mfd_add_devices(&i2c->dev, PLATFORM_DEVID_NONE,
                                           rn5t618_cells,
                                           ARRAY_SIZE(rn5t618_cells),
                                           NULL, 0, NULL);
        if (ret) {
                dev_err(&i2c->dev, "failed to add sub-devices: %d\n", ret);
                return ret;
        }

        rn5t618_pm_power_off = i2c;
        if (of_device_is_system_power_controller(i2c->dev.of_node)) {
                if (!pm_power_off)
                        pm_power_off = rn5t618_power_off;
                else
                        dev_warn(&i2c->dev, "Poweroff callback already assigned\n");
        }

        rn5t618_restart_handler.notifier_call = rn5t618_restart;
        rn5t618_restart_handler.priority = 192;

        ret = register_restart_handler(&rn5t618_restart_handler);
        if (ret) {
                dev_err(&i2c->dev, "cannot register restart handler, %d\n", ret);
                return ret;
        }

        return rn5t618_irq_init(priv);
}

static void rn5t618_i2c_remove(struct i2c_client *i2c)
{
        if (i2c == rn5t618_pm_power_off) {
                rn5t618_pm_power_off = NULL;
                pm_power_off = NULL;
        }

        unregister_restart_handler(&rn5t618_restart_handler);
}

static int __maybe_unused rn5t618_i2c_suspend(struct device *dev)
{
        struct rn5t618 *priv = dev_get_drvdata(dev);

        if (priv->irq)
                disable_irq(priv->irq);

        return 0;
}

static int __maybe_unused rn5t618_i2c_resume(struct device *dev)
{
        struct rn5t618 *priv = dev_get_drvdata(dev);

        if (priv->irq)
                enable_irq(priv->irq);

        return 0;
}

static SIMPLE_DEV_PM_OPS(rn5t618_i2c_dev_pm_ops,
                        rn5t618_i2c_suspend,
                        rn5t618_i2c_resume);

static struct i2c_driver rn5t618_i2c_driver = {
        .driver = {
                .name = "rn5t618",
                .of_match_table = rn5t618_of_match,
                .pm = &rn5t618_i2c_dev_pm_ops,
        },
        .probe = rn5t618_i2c_probe,
        .remove = rn5t618_i2c_remove,
};

module_i2c_driver(rn5t618_i2c_driver);

MODULE_AUTHOR("Beniamino Galvani <b.galvani@gmail.com>");
MODULE_DESCRIPTION("Ricoh RN5T567/618 MFD driver");
MODULE_LICENSE("GPL v2");