// SPDX-License-Identifier: GPL-2.0
/*
 * Topstar Laptop ACPI Extras driver
 *
 * Copyright (c) 2009 Herton Ronaldo Krzesinski <herton@mandriva.com.br>
 * Copyright (c) 2018 Guillaume Douézan-Grard
 *
 * Implementation inspired by existing x86 platform drivers, in special
 * asus/eepc/fujitsu-laptop, thanks to their authors.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/input.h>
#include <linux/input/sparse-keymap.h>
#include <linux/leds.h>
#include <linux/platform_device.h>

#define TOPSTAR_LAPTOP_CLASS "topstar"

struct topstar_laptop {
        struct acpi_device *device;
        struct platform_device *platform;
        struct input_dev *input;
        struct led_classdev led;
};

/*
 * LED
 */

static enum led_brightness topstar_led_get(struct led_classdev *led)
{
        return led->brightness;
}

static int topstar_led_set(struct led_classdev *led,
                enum led_brightness state)
{
        struct topstar_laptop *topstar = container_of(led,
                        struct topstar_laptop, led);

        struct acpi_object_list params;
        union acpi_object in_obj;
        unsigned long long int ret;
        acpi_status status;

        params.count = 1;
        params.pointer = &in_obj;
        in_obj.type = ACPI_TYPE_INTEGER;
        in_obj.integer.value = 0x83;

        /*
         * Topstar ACPI returns 0x30001 when the LED is ON and 0x30000 when it
         * is OFF.
         */
        status = acpi_evaluate_integer(topstar->device->handle,
                        "GETX", &params, &ret);
        if (ACPI_FAILURE(status))
                return -1;

        /*
         * FNCX(0x83) toggles the LED (more precisely, it is supposed to
         * act as an hardware switch and disconnect the WLAN adapter but
         * it seems to be faulty on some models like the Topstar U931
         * Notebook).
         */
        if ((ret == 0x30001 && state == LED_OFF)
                        || (ret == 0x30000 && state != LED_OFF)) {
                status = acpi_execute_simple_method(topstar->device->handle,
                                "FNCX", 0x83);
                if (ACPI_FAILURE(status))
                        return -1;
        }

        return 0;
}

static int topstar_led_init(struct topstar_laptop *topstar)
{
        topstar->led = (struct led_classdev) {
                .default_trigger = "rfkill0",
                .brightness_get = topstar_led_get,
                .brightness_set_blocking = topstar_led_set,
                .name = TOPSTAR_LAPTOP_CLASS "::wlan",
        };

        return led_classdev_register(&topstar->platform->dev, &topstar->led);
}

static void topstar_led_exit(struct topstar_laptop *topstar)
{
        led_classdev_unregister(&topstar->led);
}

/*
 * Input
 */

static const struct key_entry topstar_keymap[] = {
        { KE_KEY, 0x80, { KEY_BRIGHTNESSUP } },
        { KE_KEY, 0x81, { KEY_BRIGHTNESSDOWN } },
        { KE_KEY, 0x83, { KEY_VOLUMEUP } },
        { KE_KEY, 0x84, { KEY_VOLUMEDOWN } },
        { KE_KEY, 0x85, { KEY_MUTE } },
        { KE_KEY, 0x86, { KEY_SWITCHVIDEOMODE } },
        { KE_KEY, 0x87, { KEY_F13 } }, /* touchpad enable/disable key */
        { KE_KEY, 0x88, { KEY_WLAN } },
        { KE_KEY, 0x8a, { KEY_WWW } },
        { KE_KEY, 0x8b, { KEY_MAIL } },
        { KE_KEY, 0x8c, { KEY_MEDIA } },

        /* Known non hotkey events don't handled or that we don't care yet */
        { KE_IGNORE, 0x82, }, /* backlight event */
        { KE_IGNORE, 0x8e, },
        { KE_IGNORE, 0x8f, },
        { KE_IGNORE, 0x90, },

        /*
         * 'G key' generate two event codes, convert to only
         * one event/key code for now, consider replacing by
         * a switch (3G switch - SW_3G?)
         */
        { KE_KEY, 0x96, { KEY_F14 } },
        { KE_KEY, 0x97, { KEY_F14 } },

        { KE_END, 0 }
};

static void topstar_input_notify(struct topstar_laptop *topstar, int event)
{
        if (!sparse_keymap_report_event(topstar->input, event, 1, true))
                pr_info("unknown event = 0x%02x\n", event);
}

static int topstar_input_init(struct topstar_laptop *topstar)
{
        struct input_dev *input;
        int err;

        input = input_allocate_device();
        if (!input)
                return -ENOMEM;

        input->name = "Topstar Laptop extra buttons";
        input->phys = TOPSTAR_LAPTOP_CLASS "/input0";
        input->id.bustype = BUS_HOST;
        input->dev.parent = &topstar->platform->dev;

        err = sparse_keymap_setup(input, topstar_keymap, NULL);
        if (err) {
                pr_err("Unable to setup input device keymap\n");
                goto err_free_dev;
        }

        err = input_register_device(input);
        if (err) {
                pr_err("Unable to register input device\n");
                goto err_free_dev;
        }

        topstar->input = input;
        return 0;

err_free_dev:
        input_free_device(input);
        return err;
}

static void topstar_input_exit(struct topstar_laptop *topstar)
{
        input_unregister_device(topstar->input);
}

/*
 * Platform
 */

static struct platform_driver topstar_platform_driver = {
        .driver = {
                .name = TOPSTAR_LAPTOP_CLASS,
        },
};

static int topstar_platform_init(struct topstar_laptop *topstar)
{
        int err;

        topstar->platform = platform_device_alloc(TOPSTAR_LAPTOP_CLASS, PLATFORM_DEVID_NONE);
        if (!topstar->platform)
                return -ENOMEM;

        platform_set_drvdata(topstar->platform, topstar);

        err = platform_device_add(topstar->platform);
        if (err)
                goto err_device_put;

        return 0;

err_device_put:
        platform_device_put(topstar->platform);
        return err;
}

static void topstar_platform_exit(struct topstar_laptop *topstar)
{
        platform_device_unregister(topstar->platform);
}

/*
 * ACPI
 */

static int topstar_acpi_fncx_switch(struct acpi_device *device, bool state)
{
        acpi_status status;
        u64 arg = state ? 0x86 : 0x87;

        status = acpi_execute_simple_method(device->handle, "FNCX", arg);
        if (ACPI_FAILURE(status)) {
                pr_err("Unable to switch FNCX notifications\n");
                return -ENODEV;
        }

        return 0;
}

static void topstar_acpi_notify(struct acpi_device *device, u32 event)
{
        struct topstar_laptop *topstar = acpi_driver_data(device);
        static bool dup_evnt[2];
        bool *dup;

        /* 0x83 and 0x84 key events comes duplicated... */
        if (event == 0x83 || event == 0x84) {
                dup = &dup_evnt[event - 0x83];
                if (*dup) {
                        *dup = false;
                        return;
                }
                *dup = true;
        }

        topstar_input_notify(topstar, event);
}

static int topstar_acpi_init(struct topstar_laptop *topstar)
{
        return topstar_acpi_fncx_switch(topstar->device, true);
}

static void topstar_acpi_exit(struct topstar_laptop *topstar)
{
        topstar_acpi_fncx_switch(topstar->device, false);
}

/*
 * Enable software-based WLAN LED control on systems with defective
 * hardware switch.
 */
static bool led_workaround;

static int dmi_led_workaround(const struct dmi_system_id *id)
{
        led_workaround = true;
        return 0;
}

static const struct dmi_system_id topstar_dmi_ids[] = {
        {
                .callback = dmi_led_workaround,
                .ident = "Topstar U931/RVP7",
                .matches = {
                        DMI_MATCH(DMI_BOARD_NAME, "U931"),
                        DMI_MATCH(DMI_BOARD_VERSION, "RVP7"),
                },
        },
        {}
};

static int topstar_acpi_add(struct acpi_device *device)
{
        struct topstar_laptop *topstar;
        int err;

        dmi_check_system(topstar_dmi_ids);

        topstar = kzalloc_obj(struct topstar_laptop);
        if (!topstar)
                return -ENOMEM;

        strscpy(acpi_device_name(device), "Topstar TPSACPI");
        strscpy(acpi_device_class(device), TOPSTAR_LAPTOP_CLASS);
        device->driver_data = topstar;
        topstar->device = device;

        err = topstar_acpi_init(topstar);
        if (err)
                goto err_free;

        err = topstar_platform_init(topstar);
        if (err)
                goto err_acpi_exit;

        err = topstar_input_init(topstar);
        if (err)
                goto err_platform_exit;

        if (led_workaround) {
                err = topstar_led_init(topstar);
                if (err)
                        goto err_input_exit;
        }

        return 0;

err_input_exit:
        topstar_input_exit(topstar);
err_platform_exit:
        topstar_platform_exit(topstar);
err_acpi_exit:
        topstar_acpi_exit(topstar);
err_free:
        kfree(topstar);
        return err;
}

static void topstar_acpi_remove(struct acpi_device *device)
{
        struct topstar_laptop *topstar = acpi_driver_data(device);

        if (led_workaround)
                topstar_led_exit(topstar);

        topstar_input_exit(topstar);
        topstar_platform_exit(topstar);
        topstar_acpi_exit(topstar);

        kfree(topstar);
}

static const struct acpi_device_id topstar_device_ids[] = {
        { "TPS0001", 0 },
        { "TPSACPI01", 0 },
        { "", 0 },
};
MODULE_DEVICE_TABLE(acpi, topstar_device_ids);

static struct acpi_driver topstar_acpi_driver = {
        .name = "Topstar laptop ACPI driver",
        .class = TOPSTAR_LAPTOP_CLASS,
        .ids = topstar_device_ids,
        .ops = {
                .add = topstar_acpi_add,
                .remove = topstar_acpi_remove,
                .notify = topstar_acpi_notify,
        },
};

static int __init topstar_laptop_init(void)
{
        int ret;

        ret = platform_driver_register(&topstar_platform_driver);
        if (ret < 0)
                return ret;

        ret = acpi_bus_register_driver(&topstar_acpi_driver);
        if (ret < 0)
                goto err_driver_unreg;

        pr_info("ACPI extras driver loaded\n");
        return 0;

err_driver_unreg:
        platform_driver_unregister(&topstar_platform_driver);
        return ret;
}

static void __exit topstar_laptop_exit(void)
{
        acpi_bus_unregister_driver(&topstar_acpi_driver);
        platform_driver_unregister(&topstar_platform_driver);
}

module_init(topstar_laptop_init);
module_exit(topstar_laptop_exit);

MODULE_AUTHOR("Herton Ronaldo Krzesinski");
MODULE_AUTHOR("Guillaume Douézan-Grard");
MODULE_DESCRIPTION("Topstar Laptop ACPI Extras driver");
MODULE_LICENSE("GPL");