// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2025 by Aurelien Jarno
 */

#include <linux/bits.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/reboot.h>

/* Power Control Register 2 */
#define PWR_CTRL2               0x7e
#define PWR_CTRL2_SHUTDOWN      BIT(2)  /* Shutdown request */
#define PWR_CTRL2_RST           BIT(1)  /* Reset request */

static int spacemit_p1_pwroff_handler(struct sys_off_data *data)
{
        struct regmap *regmap = data->cb_data;
        int ret;

        /* Put the PMIC into shutdown state */
        ret = regmap_set_bits(regmap, PWR_CTRL2, PWR_CTRL2_SHUTDOWN);
        if (ret) {
                dev_err(data->dev, "shutdown failed: %d\n", ret);
                return notifier_from_errno(ret);
        }

        return NOTIFY_DONE;
}

static int spacemit_p1_restart_handler(struct sys_off_data *data)
{
        struct regmap *regmap = data->cb_data;
        int ret;

        /* Put the PMIC into reset state */
        ret = regmap_set_bits(regmap, PWR_CTRL2, PWR_CTRL2_RST);
        if (ret) {
                dev_err(data->dev, "restart failed: %d\n", ret);
                return notifier_from_errno(ret);
        }

        return NOTIFY_DONE;
}

static int spacemit_p1_reboot_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct regmap *regmap;
        int ret;

        regmap = dev_get_regmap(dev->parent, NULL);
        if (!regmap)
                return -ENODEV;

        ret = devm_register_power_off_handler(dev, &spacemit_p1_pwroff_handler,
                                              regmap);
        if (ret)
                return dev_err_probe(dev, ret,
                                     "Failed to register power off handler\n");

        ret = devm_register_restart_handler(dev, spacemit_p1_restart_handler,
                                            regmap);
        if (ret)
                return dev_err_probe(dev, ret,
                                     "Failed to register restart handler\n");

        return 0;
}

static const struct platform_device_id spacemit_p1_reboot_id_table[] = {
        { "spacemit-p1-reboot", },
        { /* sentinel */ },
};
MODULE_DEVICE_TABLE(platform, spacemit_p1_reboot_id_table);

static struct platform_driver spacemit_p1_reboot_driver = {
        .driver = {
                .name = "spacemit-p1-reboot",
        },
        .probe = spacemit_p1_reboot_probe,
        .id_table = spacemit_p1_reboot_id_table,
};
module_platform_driver(spacemit_p1_reboot_driver);

MODULE_DESCRIPTION("SpacemiT P1 reboot/poweroff driver");
MODULE_LICENSE("GPL");