// SPDX-License-Identifier: GPL-2.0-only
/*
 * Asus Wireless Radio Control Driver
 *
 * Copyright (C) 2015-2016 Endless Mobile, Inc.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/acpi.h>
#include <linux/input.h>
#include <linux/pci_ids.h>
#include <linux/platform_device.h>
#include <linux/leds.h>

struct hswc_params {
        u8 on;
        u8 off;
        u8 status;
};

struct asus_wireless_data {
        struct input_dev *idev;
        struct acpi_device *adev;
        const struct hswc_params *hswc_params;
        struct workqueue_struct *wq;
        struct work_struct led_work;
        struct led_classdev led;
        int led_state;
};

static const struct hswc_params atk4001_id_params = {
        .on = 0x0,
        .off = 0x1,
        .status = 0x2,
};

static const struct hswc_params atk4002_id_params = {
        .on = 0x5,
        .off = 0x4,
        .status = 0x2,
};

static const struct acpi_device_id device_ids[] = {
        {"ATK4001", (kernel_ulong_t)&atk4001_id_params},
        {"ATK4002", (kernel_ulong_t)&atk4002_id_params},
        {"", 0},
};
MODULE_DEVICE_TABLE(acpi, device_ids);

static acpi_status asus_wireless_method(acpi_handle handle, const char *method,
                                        int param, u64 *ret)
{
        struct acpi_object_list p;
        union acpi_object obj;
        acpi_status s;

        acpi_handle_debug(handle, "Evaluating method %s, parameter %#x\n",
                          method, param);
        obj.type = ACPI_TYPE_INTEGER;
        obj.integer.value = param;
        p.count = 1;
        p.pointer = &obj;

        s = acpi_evaluate_integer(handle, (acpi_string) method, &p, ret);
        if (ACPI_FAILURE(s))
                acpi_handle_err(handle,
                                "Failed to eval method %s, param %#x (%d)\n",
                                method, param, s);
        else
                acpi_handle_debug(handle, "%s returned %#llx\n", method, *ret);

        return s;
}

static enum led_brightness led_state_get(struct led_classdev *led)
{
        struct asus_wireless_data *data;
        acpi_status s;
        u64 ret;

        data = container_of(led, struct asus_wireless_data, led);
        s = asus_wireless_method(acpi_device_handle(data->adev), "HSWC",
                                 data->hswc_params->status, &ret);
        if (ACPI_SUCCESS(s) && ret == data->hswc_params->on)
                return LED_FULL;
        return LED_OFF;
}

static void led_state_update(struct work_struct *work)
{
        struct asus_wireless_data *data;
        u64 ret;

        data = container_of(work, struct asus_wireless_data, led_work);
        asus_wireless_method(acpi_device_handle(data->adev), "HSWC",
                             data->led_state, &ret);
}

static void led_state_set(struct led_classdev *led, enum led_brightness value)
{
        struct asus_wireless_data *data;

        data = container_of(led, struct asus_wireless_data, led);
        data->led_state = value == LED_OFF ? data->hswc_params->off :
                                             data->hswc_params->on;
        queue_work(data->wq, &data->led_work);
}

static void asus_wireless_notify(acpi_handle handle, u32 event, void *context)
{
        struct asus_wireless_data *data = context;
        struct acpi_device *adev = data->adev;

        dev_dbg(&adev->dev, "event=%#x\n", event);
        if (event != 0x88) {
                dev_notice(&adev->dev, "Unknown ASHS event: %#x\n", event);
                return;
        }
        input_report_key(data->idev, KEY_RFKILL, 1);
        input_sync(data->idev);
        input_report_key(data->idev, KEY_RFKILL, 0);
        input_sync(data->idev);
}

static int asus_wireless_probe(struct platform_device *pdev)
{
        struct acpi_device *adev = ACPI_COMPANION(&pdev->dev);
        struct asus_wireless_data *data;
        const struct acpi_device_id *id;
        int err;

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

        platform_set_drvdata(pdev, data);

        data->adev = adev;

        data->idev = devm_input_allocate_device(&pdev->dev);
        if (!data->idev)
                return -ENOMEM;
        data->idev->name = "Asus Wireless Radio Control";
        data->idev->phys = "asus-wireless/input0";
        data->idev->id.bustype = BUS_HOST;
        data->idev->id.vendor = PCI_VENDOR_ID_ASUSTEK;
        set_bit(EV_KEY, data->idev->evbit);
        set_bit(KEY_RFKILL, data->idev->keybit);
        err = input_register_device(data->idev);
        if (err)
                return err;

        id = acpi_match_acpi_device(device_ids, adev);
        if (!id)
                return 0;

        data->hswc_params = (const struct hswc_params *)id->driver_data;

        data->wq = create_singlethread_workqueue("asus_wireless_workqueue");
        if (!data->wq)
                return -ENOMEM;
        INIT_WORK(&data->led_work, led_state_update);
        data->led.name = "asus-wireless::airplane";
        data->led.brightness_set = led_state_set;
        data->led.brightness_get = led_state_get;
        data->led.flags = LED_CORE_SUSPENDRESUME;
        data->led.max_brightness = 1;
        data->led.default_trigger = "rfkill-none";
        err = devm_led_classdev_register(&pdev->dev, &data->led);
        if (err)
                goto err;

        err = acpi_dev_install_notify_handler(adev, ACPI_DEVICE_NOTIFY,
                                              asus_wireless_notify, data);
        if (err) {
                devm_led_classdev_unregister(&pdev->dev, &data->led);
                goto err;
        }
        return 0;

err:
        destroy_workqueue(data->wq);
        return err;
}

static void asus_wireless_remove(struct platform_device *pdev)
{
        struct asus_wireless_data *data = platform_get_drvdata(pdev);

        acpi_dev_remove_notify_handler(data->adev, ACPI_DEVICE_NOTIFY,
                                       asus_wireless_notify);
        if (data->wq) {
                devm_led_classdev_unregister(&pdev->dev, &data->led);
                destroy_workqueue(data->wq);
        }
}

static struct platform_driver asus_wireless_driver = {
        .probe = asus_wireless_probe,
        .remove = asus_wireless_remove,
        .driver = {
                .name = "Asus Wireless Radio Control Driver",
                .acpi_match_table = device_ids,
        },
};
module_platform_driver(asus_wireless_driver);

MODULE_DESCRIPTION("Asus Wireless Radio Control Driver");
MODULE_AUTHOR("João Paulo Rechi Vita <jprvita@gmail.com>");
MODULE_LICENSE("GPL");