// SPDX-License-Identifier: GPL-2.0+
/*
 * Poweroff & reset driver for Actions Semi ATC260x PMICs
 *
 * Copyright (c) 2020 Cristian Ciocaltea <cristian.ciocaltea@gmail.com>
 */

#include <linux/delay.h>
#include <linux/mfd/atc260x/core.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/reboot.h>
#include <linux/regmap.h>

struct atc260x_pwrc {
        struct device *dev;
        struct regmap *regmap;
        int (*do_poweroff)(const struct atc260x_pwrc *pwrc, bool restart);
};

static int atc2603c_do_poweroff(const struct atc260x_pwrc *pwrc, bool restart)
{
        int ret, deep_sleep = 0;
        uint reg_mask, reg_val;

        /* S4-Deep Sleep Mode is NOT available for WALL/USB power */
        if (!restart && !power_supply_is_system_supplied()) {
                deep_sleep = 1;
                dev_info(pwrc->dev, "Enabling S4-Deep Sleep Mode");
        }

        /* Update wakeup sources */
        reg_val = ATC2603C_PMU_SYS_CTL0_ONOFF_LONG_WK_EN |
                  (restart ? ATC2603C_PMU_SYS_CTL0_RESET_WK_EN
                           : ATC2603C_PMU_SYS_CTL0_ONOFF_SHORT_WK_EN);

        ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL0,
                                 ATC2603C_PMU_SYS_CTL0_WK_ALL, reg_val);
        if (ret)
                dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);

        /* Update power mode */
        reg_mask = ATC2603C_PMU_SYS_CTL3_EN_S2 | ATC2603C_PMU_SYS_CTL3_EN_S3;

        ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL3, reg_mask,
                                 deep_sleep ? 0 : ATC2603C_PMU_SYS_CTL3_EN_S3);
        if (ret) {
                dev_err(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
                return ret;
        }

        /* Trigger poweroff / restart sequence */
        reg_mask = restart ? ATC2603C_PMU_SYS_CTL0_RESTART_EN
                           : ATC2603C_PMU_SYS_CTL1_EN_S1;
        reg_val = restart ? ATC2603C_PMU_SYS_CTL0_RESTART_EN : 0;

        ret = regmap_update_bits(pwrc->regmap,
                                 restart ? ATC2603C_PMU_SYS_CTL0 : ATC2603C_PMU_SYS_CTL1,
                                 reg_mask, reg_val);
        if (ret) {
                dev_err(pwrc->dev, "failed to write SYS_CTL%d: %d\n",
                        restart ? 0 : 1, ret);
                return ret;
        }

        /* Wait for trigger completion */
        mdelay(200);

        return 0;
}

static int atc2609a_do_poweroff(const struct atc260x_pwrc *pwrc, bool restart)
{
        int ret, deep_sleep = 0;
        uint reg_mask, reg_val;

        /* S4-Deep Sleep Mode is NOT available for WALL/USB power */
        if (!restart && !power_supply_is_system_supplied()) {
                deep_sleep = 1;
                dev_info(pwrc->dev, "Enabling S4-Deep Sleep Mode");
        }

        /* Update wakeup sources */
        reg_val = ATC2609A_PMU_SYS_CTL0_ONOFF_LONG_WK_EN |
                  (restart ? ATC2609A_PMU_SYS_CTL0_RESET_WK_EN
                           : ATC2609A_PMU_SYS_CTL0_ONOFF_SHORT_WK_EN);

        ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL0,
                                 ATC2609A_PMU_SYS_CTL0_WK_ALL, reg_val);
        if (ret)
                dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);

        /* Update power mode */
        reg_mask = ATC2609A_PMU_SYS_CTL3_EN_S2 | ATC2609A_PMU_SYS_CTL3_EN_S3;

        ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL3, reg_mask,
                                 deep_sleep ? 0 : ATC2609A_PMU_SYS_CTL3_EN_S3);
        if (ret) {
                dev_err(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);
                return ret;
        }

        /* Trigger poweroff / restart sequence */
        reg_mask = restart ? ATC2609A_PMU_SYS_CTL0_RESTART_EN
                           : ATC2609A_PMU_SYS_CTL1_EN_S1;
        reg_val = restart ? ATC2609A_PMU_SYS_CTL0_RESTART_EN : 0;

        ret = regmap_update_bits(pwrc->regmap,
                                 restart ? ATC2609A_PMU_SYS_CTL0 : ATC2609A_PMU_SYS_CTL1,
                                 reg_mask, reg_val);
        if (ret) {
                dev_err(pwrc->dev, "failed to write SYS_CTL%d: %d\n",
                        restart ? 0 : 1, ret);
                return ret;
        }

        /* Wait for trigger completion */
        mdelay(200);

        return 0;
}

static int atc2603c_init(const struct atc260x_pwrc *pwrc)
{
        int ret;

        /*
         * Delay transition from S2/S3 to S1 in order to avoid
         * DDR init failure in Bootloader.
         */
        ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL3,
                                 ATC2603C_PMU_SYS_CTL3_S2S3TOS1_TIMER_EN,
                                 ATC2603C_PMU_SYS_CTL3_S2S3TOS1_TIMER_EN);
        if (ret)
                dev_warn(pwrc->dev, "failed to write SYS_CTL3: %d\n", ret);

        /* Set wakeup sources */
        ret = regmap_update_bits(pwrc->regmap, ATC2603C_PMU_SYS_CTL0,
                                 ATC2603C_PMU_SYS_CTL0_WK_ALL,
                                 ATC2603C_PMU_SYS_CTL0_HDSW_WK_EN |
                                 ATC2603C_PMU_SYS_CTL0_ONOFF_LONG_WK_EN);
        if (ret)
                dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);

        return ret;
}

static int atc2609a_init(const struct atc260x_pwrc *pwrc)
{
        int ret;

        /* Set wakeup sources */
        ret = regmap_update_bits(pwrc->regmap, ATC2609A_PMU_SYS_CTL0,
                                 ATC2609A_PMU_SYS_CTL0_WK_ALL,
                                 ATC2609A_PMU_SYS_CTL0_HDSW_WK_EN |
                                 ATC2609A_PMU_SYS_CTL0_ONOFF_LONG_WK_EN);
        if (ret)
                dev_warn(pwrc->dev, "failed to write SYS_CTL0: %d\n", ret);

        return ret;
}

static int atc260x_pwrc_pm_handler(struct sys_off_data *data)
{
        struct atc260x_pwrc *pwrc = data->cb_data;

        pwrc->do_poweroff(pwrc, false);

        WARN_ONCE(1, "Unable to power off system\n");

        return NOTIFY_DONE;
}

static int atc260x_pwrc_restart_handler(struct sys_off_data *data)
{
        struct atc260x_pwrc *pwrc = data->cb_data;
        pwrc->do_poweroff(pwrc, true);

        return NOTIFY_DONE;
}

static int atc260x_pwrc_probe(struct platform_device *pdev)
{
        struct atc260x *atc260x = dev_get_drvdata(pdev->dev.parent);
        struct atc260x_pwrc *priv;
        int ret;

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

        priv->dev = &pdev->dev;
        priv->regmap = atc260x->regmap;

        switch (atc260x->ic_type) {
        case ATC2603C:
                priv->do_poweroff = atc2603c_do_poweroff;
                ret = atc2603c_init(priv);
                break;
        case ATC2609A:
                priv->do_poweroff = atc2609a_do_poweroff;
                ret = atc2609a_init(priv);
                break;
        default:
                dev_err(priv->dev,
                        "Poweroff not supported for ATC260x PMIC type: %u\n",
                        atc260x->ic_type);
                return -EINVAL;
        }

        if (ret)
                return ret;

        ret = devm_register_sys_off_handler(priv->dev,
                                            SYS_OFF_MODE_POWER_OFF,
                                            SYS_OFF_PRIO_DEFAULT,
                                            atc260x_pwrc_pm_handler,
                                            priv);
        if (ret)
                dev_err(priv->dev, "failed to register power-off handler: %d\n",
                        ret);

        ret = devm_register_sys_off_handler(priv->dev,
                                            SYS_OFF_MODE_RESTART,
                                            SYS_OFF_PRIO_HIGH,
                                            atc260x_pwrc_restart_handler,
                                            priv);
        if (ret)
                dev_err(priv->dev, "failed to register restart handler: %d\n",
                        ret);

        return ret;
}

static struct platform_driver atc260x_pwrc_driver = {
        .probe = atc260x_pwrc_probe,
        .driver = {
                .name = "atc260x-pwrc",
        },
};

module_platform_driver(atc260x_pwrc_driver);

MODULE_DESCRIPTION("Poweroff & reset driver for ATC260x PMICs");
MODULE_AUTHOR("Cristian Ciocaltea <cristian.ciocaltea@gmail.com>");
MODULE_LICENSE("GPL");