root/drivers/power/reset/tps65086-restart.c
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2021 Emil Renner Berthing
 */

#include <linux/mfd/tps65086.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>

static int tps65086_restart_notify(struct sys_off_data *data)
{
        struct tps65086 *tps65086 = data->cb_data;
        int ret;

        ret = regmap_write(tps65086->regmap, TPS65086_FORCESHUTDN, 1);
        if (ret) {
                dev_err(tps65086->dev, "%s: error writing to tps65086 pmic: %d\n",
                        __func__, ret);
                return NOTIFY_DONE;
        }

        /* give it a little time */
        mdelay(200);

        WARN_ON(1);

        return NOTIFY_DONE;
}

static int tps65086_restart_probe(struct platform_device *pdev)
{
        struct tps65086 *tps65086 = dev_get_drvdata(pdev->dev.parent);

        return devm_register_sys_off_handler(&pdev->dev,
                                             SYS_OFF_MODE_RESTART,
                                             SYS_OFF_PRIO_HIGH,
                                             tps65086_restart_notify,
                                             tps65086);
}

static const struct platform_device_id tps65086_restart_id_table[] = {
        { "tps65086-reset", },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, tps65086_restart_id_table);

static struct platform_driver tps65086_restart_driver = {
        .driver = {
                .name = "tps65086-restart",
        },
        .probe = tps65086_restart_probe,
        .id_table = tps65086_restart_id_table,
};
module_platform_driver(tps65086_restart_driver);

MODULE_AUTHOR("Emil Renner Berthing <kernel@esmil.dk>");
MODULE_DESCRIPTION("TPS65086 restart driver");