// SPDX-License-Identifier: GPL-2.0+
/*
 * Copyright (c) 2023 Neil Armstrong <neil.armstrong@linaro.org>
 */
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mfd/rk808.h>
#include <linux/regmap.h>
#include <linux/module.h>
#include <linux/reboot.h>
#include <linux/i2c.h>

/*
 * The Odroid Go Ultra has 2 PMICs:
 * - RK818 (manages the battery and USB-C power supply)
 * - RK817
 * Both PMICs feeds power to the S922X SoC, so they must be powered-off in sequence.
 * Vendor does power-off the RK817 first, then the RK818 so here we follow this sequence.
 */

struct odroid_go_ultra_poweroff_data {
        struct device *dev;
        struct device *rk817;
        struct device *rk818;
};

static int odroid_go_ultra_poweroff_prepare(struct sys_off_data *data)
{
        struct odroid_go_ultra_poweroff_data *poweroff_data = data->cb_data;
        struct regmap *rk817, *rk818;
        int ret;

        /* RK817 Regmap */
        rk817 = dev_get_regmap(poweroff_data->rk817, NULL);
        if (!rk817) {
                dev_err(poweroff_data->dev, "failed to get rk817 regmap\n");
                return notifier_from_errno(-EINVAL);
        }

        /* RK818 Regmap */
        rk818 = dev_get_regmap(poweroff_data->rk818, NULL);
        if (!rk818) {
                dev_err(poweroff_data->dev, "failed to get rk818 regmap\n");
                return notifier_from_errno(-EINVAL);
        }

        dev_info(poweroff_data->dev, "Setting PMICs for power off");

        /* RK817 */
        ret = regmap_update_bits(rk817, RK817_SYS_CFG(3), DEV_OFF, DEV_OFF);
        if (ret) {
                dev_err(poweroff_data->dev, "failed to poweroff rk817\n");
                return notifier_from_errno(ret);
        }

        /* RK818 */
        ret = regmap_update_bits(rk818, RK818_DEVCTRL_REG, DEV_OFF, DEV_OFF);
        if (ret) {
                dev_err(poweroff_data->dev, "failed to poweroff rk818\n");
                return notifier_from_errno(ret);
        }

        return NOTIFY_OK;
}

static void odroid_go_ultra_poweroff_put_pmic_device(void *data)
{
        struct device *dev = data;

        put_device(dev);
}

static int odroid_go_ultra_poweroff_get_pmic_device(struct device *dev, const char *compatible,
                                                    struct device **pmic)
{
        struct device_node *pmic_node;
        struct i2c_client *pmic_client;

        pmic_node = of_find_compatible_node(NULL, NULL, compatible);
        if (!pmic_node)
                return -ENODEV;

        pmic_client = of_find_i2c_device_by_node(pmic_node);
        of_node_put(pmic_node);
        if (!pmic_client)
                return -EPROBE_DEFER;

        *pmic = &pmic_client->dev;

        return devm_add_action_or_reset(dev, odroid_go_ultra_poweroff_put_pmic_device, *pmic);
}

static int odroid_go_ultra_poweroff_probe(struct platform_device *pdev)
{
        struct odroid_go_ultra_poweroff_data *poweroff_data;
        int ret;

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

        dev_set_drvdata(&pdev->dev, poweroff_data);

        /* RK818 PMIC Device */
        ret = odroid_go_ultra_poweroff_get_pmic_device(&pdev->dev, "rockchip,rk818",
                                                       &poweroff_data->rk818);
        if (ret)
                return dev_err_probe(&pdev->dev, ret, "failed to get rk818 mfd data\n");

        /* RK817 PMIC Device */
        ret = odroid_go_ultra_poweroff_get_pmic_device(&pdev->dev, "rockchip,rk817",
                                                       &poweroff_data->rk817);
        if (ret)
                return dev_err_probe(&pdev->dev, ret, "failed to get rk817 mfd data\n");

        /* Register as SYS_OFF_MODE_POWER_OFF_PREPARE because regmap_update_bits may sleep */
        ret = devm_register_sys_off_handler(&pdev->dev,
                                            SYS_OFF_MODE_POWER_OFF_PREPARE,
                                            SYS_OFF_PRIO_DEFAULT,
                                            odroid_go_ultra_poweroff_prepare,
                                            poweroff_data);
        if (ret)
                return dev_err_probe(&pdev->dev, ret, "failed to register sys-off handler\n");

        dev_info(&pdev->dev, "Registered Power-Off handler\n");

        return 0;
}
static struct platform_device *pdev;

static struct platform_driver odroid_go_ultra_poweroff_driver = {
        .driver = {
                .name   = "odroid-go-ultra-poweroff",
        },
        .probe = odroid_go_ultra_poweroff_probe,
};

static int __init odroid_go_ultra_poweroff_init(void)
{
        int ret;

        /* Only create when running on the Odroid Go Ultra device */
        if (!of_device_is_compatible(of_root, "hardkernel,odroid-go-ultra"))
                return -ENODEV;

        ret = platform_driver_register(&odroid_go_ultra_poweroff_driver);
        if (ret)
                return ret;

        pdev = platform_device_register_resndata(NULL, "odroid-go-ultra-poweroff", -1,
                                                 NULL, 0, NULL, 0);

        if (IS_ERR(pdev)) {
                platform_driver_unregister(&odroid_go_ultra_poweroff_driver);
                return PTR_ERR(pdev);
        }

        return 0;
}

static void __exit odroid_go_ultra_poweroff_exit(void)
{
        /* Only delete when running on the Odroid Go Ultra device */
        if (!of_device_is_compatible(of_root, "hardkernel,odroid-go-ultra"))
                return;

        platform_device_unregister(pdev);
        platform_driver_unregister(&odroid_go_ultra_poweroff_driver);
}

module_init(odroid_go_ultra_poweroff_init);
module_exit(odroid_go_ultra_poweroff_exit);

MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");
MODULE_DESCRIPTION("Odroid Go Ultra poweroff driver");
MODULE_LICENSE("GPL");