// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2016, Fuzhou Rockchip Electronics Co., Ltd
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/reboot.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/reboot-mode.h>

struct syscon_reboot_mode {
        struct regmap *map;
        struct reboot_mode_driver reboot;
        u32 offset;
        u32 mask;
};

static int syscon_reboot_mode_write(struct reboot_mode_driver *reboot,
                                    unsigned int magic)
{
        struct syscon_reboot_mode *syscon_rbm;
        int ret;

        syscon_rbm = container_of(reboot, struct syscon_reboot_mode, reboot);

        ret = regmap_update_bits(syscon_rbm->map, syscon_rbm->offset,
                                 syscon_rbm->mask, magic);
        if (ret < 0)
                dev_err(reboot->dev, "update reboot mode bits failed\n");

        return ret;
}

static int syscon_reboot_mode_probe(struct platform_device *pdev)
{
        int ret;
        struct syscon_reboot_mode *syscon_rbm;

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

        syscon_rbm->reboot.dev = &pdev->dev;
        syscon_rbm->reboot.write = syscon_reboot_mode_write;
        syscon_rbm->mask = 0xffffffff;

        syscon_rbm->map = syscon_node_to_regmap(pdev->dev.parent->of_node);
        if (IS_ERR(syscon_rbm->map))
                return PTR_ERR(syscon_rbm->map);

        if (of_property_read_u32(pdev->dev.of_node, "offset",
            &syscon_rbm->offset))
                return -EINVAL;

        of_property_read_u32(pdev->dev.of_node, "mask", &syscon_rbm->mask);

        ret = devm_reboot_mode_register(&pdev->dev, &syscon_rbm->reboot);
        if (ret)
                dev_err(&pdev->dev, "can't register reboot mode\n");

        return ret;
}

static const struct of_device_id syscon_reboot_mode_of_match[] = {
        { .compatible = "syscon-reboot-mode" },
        {}
};
MODULE_DEVICE_TABLE(of, syscon_reboot_mode_of_match);

static struct platform_driver syscon_reboot_mode_driver = {
        .probe = syscon_reboot_mode_probe,
        .driver = {
                .name = "syscon-reboot-mode",
                .of_match_table = syscon_reboot_mode_of_match,
        },
};
module_platform_driver(syscon_reboot_mode_driver);

MODULE_AUTHOR("Andy Yan <andy.yan@rock-chips.com");
MODULE_DESCRIPTION("SYSCON reboot mode driver");
MODULE_LICENSE("GPL v2");