// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  acpi_ac.c - ACPI AC Adapter Driver (Revision: 27)
 *
 *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
 *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
 */

#define pr_fmt(fmt) "ACPI: AC: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/dmi.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/string_choices.h>
#include <linux/acpi.h>
#include <acpi/battery.h>

#define ACPI_AC_CLASS                   "ac_adapter"
#define ACPI_AC_DEVICE_NAME             "AC Adapter"
#define ACPI_AC_FILE_STATE              "state"
#define ACPI_AC_NOTIFY_STATUS           0x80
#define ACPI_AC_STATUS_OFFLINE          0x00
#define ACPI_AC_STATUS_ONLINE           0x01
#define ACPI_AC_STATUS_UNKNOWN          0xFF

MODULE_AUTHOR("Paul Diefenbaugh");
MODULE_DESCRIPTION("ACPI AC Adapter Driver");
MODULE_LICENSE("GPL");

static int acpi_ac_probe(struct platform_device *pdev);
static void acpi_ac_remove(struct platform_device *pdev);

static void acpi_ac_notify(acpi_handle handle, u32 event, void *data);

static const struct acpi_device_id ac_device_ids[] = {
        {"ACPI0003", 0},
        {"", 0},
};
MODULE_DEVICE_TABLE(acpi, ac_device_ids);

#ifdef CONFIG_PM_SLEEP
static int acpi_ac_resume(struct device *dev);
#endif
static SIMPLE_DEV_PM_OPS(acpi_ac_pm, NULL, acpi_ac_resume);

static int ac_sleep_before_get_state_ms;
static int ac_only;

struct acpi_ac {
        struct power_supply *charger;
        struct power_supply_desc charger_desc;
        struct acpi_device *device;
        unsigned long long state;
        struct notifier_block battery_nb;
};

#define to_acpi_ac(x) power_supply_get_drvdata(x)

/* AC Adapter Management */
static int acpi_ac_get_state(struct acpi_ac *ac)
{
        acpi_status status = AE_OK;

        if (!ac)
                return -EINVAL;

        if (ac_only) {
                ac->state = 1;
                return 0;
        }

        status = acpi_evaluate_integer(ac->device->handle, "_PSR", NULL,
                                       &ac->state);
        if (ACPI_FAILURE(status)) {
                acpi_handle_info(ac->device->handle,
                                "Error reading AC Adapter state: %s\n",
                                acpi_format_exception(status));
                ac->state = ACPI_AC_STATUS_UNKNOWN;
                return -ENODEV;
        }

        return 0;
}

/* sysfs I/F */
static int get_ac_property(struct power_supply *psy,
                           enum power_supply_property psp,
                           union power_supply_propval *val)
{
        struct acpi_ac *ac = to_acpi_ac(psy);

        if (!ac)
                return -ENODEV;

        if (acpi_ac_get_state(ac))
                return -ENODEV;

        switch (psp) {
        case POWER_SUPPLY_PROP_ONLINE:
                val->intval = ac->state;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static const enum power_supply_property ac_props[] = {
        POWER_SUPPLY_PROP_ONLINE,
};

/* Driver Model */
static void acpi_ac_notify(acpi_handle handle, u32 event, void *data)
{
        struct acpi_ac *ac = data;
        struct acpi_device *adev = ac->device;

        switch (event) {
        default:
                acpi_handle_debug(adev->handle, "Unsupported event [0x%x]\n",
                                  event);
                fallthrough;
        case ACPI_AC_NOTIFY_STATUS:
        case ACPI_NOTIFY_BUS_CHECK:
        case ACPI_NOTIFY_DEVICE_CHECK:
                /*
                 * A buggy BIOS may notify AC first and then sleep for
                 * a specific time before doing actual operations in the
                 * EC event handler (_Qxx). This will cause the AC state
                 * reported by the ACPI event to be incorrect, so wait for a
                 * specific time for the EC event handler to make progress.
                 */
                if (ac_sleep_before_get_state_ms > 0)
                        msleep(ac_sleep_before_get_state_ms);

                acpi_ac_get_state(ac);
                acpi_bus_generate_netlink_event(adev->pnp.device_class,
                                                  dev_name(&adev->dev), event,
                                                  (u32) ac->state);
                acpi_notifier_call_chain(adev, event, (u32) ac->state);
                power_supply_changed(ac->charger);
        }
}

static int acpi_ac_battery_notify(struct notifier_block *nb,
                                  unsigned long action, void *data)
{
        struct acpi_ac *ac = container_of(nb, struct acpi_ac, battery_nb);
        struct acpi_bus_event *event = (struct acpi_bus_event *)data;

        /*
         * On HP Pavilion dv6-6179er AC status notifications aren't triggered
         * when adapter is plugged/unplugged. However, battery status
         * notifications are triggered when battery starts charging or
         * discharging. Re-reading AC status triggers lost AC notifications,
         * if AC status has changed.
         */
        if (strcmp(event->device_class, ACPI_BATTERY_CLASS) == 0 &&
            event->type == ACPI_BATTERY_NOTIFY_STATUS)
                acpi_ac_get_state(ac);

        return NOTIFY_OK;
}

static int __init thinkpad_e530_quirk(const struct dmi_system_id *d)
{
        ac_sleep_before_get_state_ms = 1000;
        return 0;
}

static int __init ac_only_quirk(const struct dmi_system_id *d)
{
        ac_only = 1;
        return 0;
}

/* Please keep this list alphabetically sorted */
static const struct dmi_system_id ac_dmi_table[]  __initconst = {
        {
                /* Kodlix GK45 returning incorrect state */
                .callback = ac_only_quirk,
                .matches = {
                        DMI_MATCH(DMI_PRODUCT_NAME, "GK45"),
                },
        },
        {
                /* Lenovo Thinkpad e530, see comment in acpi_ac_notify() */
                .callback = thinkpad_e530_quirk,
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "32597CG"),
                },
        },
        {},
};

static int acpi_ac_probe(struct platform_device *pdev)
{
        struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
        struct power_supply_config psy_cfg = {};
        struct acpi_ac *ac;
        int result;

        ac = kzalloc_obj(struct acpi_ac);
        if (!ac)
                return -ENOMEM;

        ac->device = adev;
        strscpy(acpi_device_name(adev), ACPI_AC_DEVICE_NAME);
        strscpy(acpi_device_class(adev), ACPI_AC_CLASS);

        platform_set_drvdata(pdev, ac);

        result = acpi_ac_get_state(ac);
        if (result)
                goto err_release_ac;

        psy_cfg.drv_data = ac;

        ac->charger_desc.name = acpi_device_bid(adev);
        ac->charger_desc.type = POWER_SUPPLY_TYPE_MAINS;
        ac->charger_desc.properties = ac_props;
        ac->charger_desc.num_properties = ARRAY_SIZE(ac_props);
        ac->charger_desc.get_property = get_ac_property;
        ac->charger = power_supply_register(&pdev->dev,
                                            &ac->charger_desc, &psy_cfg);
        if (IS_ERR(ac->charger)) {
                result = PTR_ERR(ac->charger);
                goto err_release_ac;
        }

        pr_info("%s [%s] (%s-line)\n", acpi_device_name(adev),
                acpi_device_bid(adev), str_on_off(ac->state));

        ac->battery_nb.notifier_call = acpi_ac_battery_notify;
        register_acpi_notifier(&ac->battery_nb);

        result = acpi_dev_install_notify_handler(adev, ACPI_ALL_NOTIFY,
                                                 acpi_ac_notify, ac);
        if (result)
                goto err_unregister;

        return 0;

err_unregister:
        power_supply_unregister(ac->charger);
        unregister_acpi_notifier(&ac->battery_nb);
err_release_ac:
        kfree(ac);

        return result;
}

#ifdef CONFIG_PM_SLEEP
static int acpi_ac_resume(struct device *dev)
{
        struct acpi_ac *ac = dev_get_drvdata(dev);
        unsigned int old_state;

        old_state = ac->state;
        if (acpi_ac_get_state(ac))
                return 0;
        if (old_state != ac->state)
                power_supply_changed(ac->charger);

        return 0;
}
#else
#define acpi_ac_resume NULL
#endif

static void acpi_ac_remove(struct platform_device *pdev)
{
        struct acpi_ac *ac = platform_get_drvdata(pdev);

        acpi_dev_remove_notify_handler(ac->device, ACPI_ALL_NOTIFY,
                                       acpi_ac_notify);
        power_supply_unregister(ac->charger);
        unregister_acpi_notifier(&ac->battery_nb);

        kfree(ac);
}

static struct platform_driver acpi_ac_driver = {
        .probe = acpi_ac_probe,
        .remove = acpi_ac_remove,
        .driver = {
                .name = "ac",
                .acpi_match_table = ac_device_ids,
                .pm = &acpi_ac_pm,
        },
};

static int __init acpi_ac_init(void)
{
        int result;

        if (acpi_disabled)
                return -ENODEV;

        if (acpi_quirk_skip_acpi_ac_and_battery())
                return -ENODEV;

        dmi_check_system(ac_dmi_table);

        result = platform_driver_register(&acpi_ac_driver);
        if (result < 0)
                return -ENODEV;

        return 0;
}

static void __exit acpi_ac_exit(void)
{
        platform_driver_unregister(&acpi_ac_driver);
}
module_init(acpi_ac_init);
module_exit(acpi_ac_exit);