// SPDX-License-Identifier: GPL-2.0-only
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/module.h>

#include <linux/platform_device.h>
#include <linux/err.h>
#include <linux/leds.h>

#include <linux/io.h>
#include <linux/dmi.h>

#include <linux/i8042.h>

#define CLEVO_MAIL_LED_OFF              0x0084
#define CLEVO_MAIL_LED_BLINK_1HZ        0x008A
#define CLEVO_MAIL_LED_BLINK_0_5HZ      0x0083

MODULE_AUTHOR("Márton Németh <nm127@freemail.hu>");
MODULE_DESCRIPTION("Clevo mail LED driver");
MODULE_LICENSE("GPL");

static bool nodetect;
module_param_named(nodetect, nodetect, bool, 0);
MODULE_PARM_DESC(nodetect, "Skip DMI hardware detection");

static struct platform_device *pdev;

static int __init clevo_mail_led_dmi_callback(const struct dmi_system_id *id)
{
        pr_info("'%s' found\n", id->ident);
        return 1;
}

/*
 * struct clevo_mail_led_dmi_table - List of known good models
 *
 * Contains the known good models this driver is compatible with.
 * When adding a new model try to be as strict as possible. This
 * makes it possible to keep the false positives (the model is
 * detected as working, but in reality it is not) as low as
 * possible.
 */
static const struct dmi_system_id clevo_mail_led_dmi_table[] __initconst = {
        {
                .callback = clevo_mail_led_dmi_callback,
                .ident = "Clevo D410J",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "VIA"),
                        DMI_MATCH(DMI_PRODUCT_NAME, "K8N800"),
                        DMI_MATCH(DMI_PRODUCT_VERSION, "VT8204B")
                }
        },
        {
                .callback = clevo_mail_led_dmi_callback,
                .ident = "Clevo M5x0N",
                .matches = {
                        DMI_MATCH(DMI_SYS_VENDOR, "CLEVO Co."),
                        DMI_MATCH(DMI_PRODUCT_NAME, "M5x0N")
                }
        },
        {
                .callback = clevo_mail_led_dmi_callback,
                .ident = "Clevo M5x0V",
                .matches = {
                        DMI_MATCH(DMI_BOARD_VENDOR, "CLEVO Co. "),
                        DMI_MATCH(DMI_BOARD_NAME, "M5X0V "),
                        DMI_MATCH(DMI_PRODUCT_VERSION, "VT6198")
                }
        },
        {
                .callback = clevo_mail_led_dmi_callback,
                .ident = "Clevo D400P",
                .matches = {
                        DMI_MATCH(DMI_BOARD_VENDOR, "Clevo"),
                        DMI_MATCH(DMI_BOARD_NAME, "D400P"),
                        DMI_MATCH(DMI_BOARD_VERSION, "Rev.A"),
                        DMI_MATCH(DMI_PRODUCT_VERSION, "0106")
                }
        },
        {
                .callback = clevo_mail_led_dmi_callback,
                .ident = "Clevo D410V",
                .matches = {
                        DMI_MATCH(DMI_BOARD_VENDOR, "Clevo, Co."),
                        DMI_MATCH(DMI_BOARD_NAME, "D400V/D470V"),
                        DMI_MATCH(DMI_BOARD_VERSION, "SS78B"),
                        DMI_MATCH(DMI_PRODUCT_VERSION, "Rev. A1")
                }
        },
        { }
};
MODULE_DEVICE_TABLE(dmi, clevo_mail_led_dmi_table);

static void clevo_mail_led_set(struct led_classdev *led_cdev,
                                enum led_brightness value)
{
        i8042_lock_chip();

        if (value == LED_OFF)
                i8042_command(NULL, CLEVO_MAIL_LED_OFF);
        else if (value <= LED_HALF)
                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ);
        else
                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_1HZ);

        i8042_unlock_chip();

}

static int clevo_mail_led_blink(struct led_classdev *led_cdev,
                                unsigned long *delay_on,
                                unsigned long *delay_off)
{
        int status = -EINVAL;

        i8042_lock_chip();

        if (*delay_on == 0 /* ms */ && *delay_off == 0 /* ms */) {
                /* Special case: the leds subsystem requested us to
                 * chose one user friendly blinking of the LED, and
                 * start it. Let's blink the led slowly (0.5Hz).
                 */
                *delay_on = 1000; /* ms */
                *delay_off = 1000; /* ms */
                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ);
                status = 0;

        } else if (*delay_on == 500 /* ms */ && *delay_off == 500 /* ms */) {
                /* blink the led with 1Hz */
                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_1HZ);
                status = 0;

        } else if (*delay_on == 1000 /* ms */ && *delay_off == 1000 /* ms */) {
                /* blink the led with 0.5Hz */
                i8042_command(NULL, CLEVO_MAIL_LED_BLINK_0_5HZ);
                status = 0;

        } else {
                pr_debug("clevo_mail_led_blink(..., %lu, %lu),"
                       " returning -EINVAL (unsupported)\n",
                       *delay_on, *delay_off);
        }

        i8042_unlock_chip();

        return status;
}

static struct led_classdev clevo_mail_led = {
        .name                   = "clevo::mail",
        .brightness_set         = clevo_mail_led_set,
        .blink_set              = clevo_mail_led_blink,
        .flags                  = LED_CORE_SUSPENDRESUME,
};

static int __init clevo_mail_led_probe(struct platform_device *pdev)
{
        return led_classdev_register(&pdev->dev, &clevo_mail_led);
}

static int clevo_mail_led_remove(struct platform_device *pdev)
{
        led_classdev_unregister(&clevo_mail_led);
        return 0;
}

static struct platform_driver clevo_mail_led_driver = {
        .remove         = clevo_mail_led_remove,
        .driver         = {
                .name           = KBUILD_MODNAME,
        },
};

static int __init clevo_mail_led_init(void)
{
        int error = 0;
        int count = 0;

        /* Check with the help of DMI if we are running on supported hardware */
        if (!nodetect) {
                count = dmi_check_system(clevo_mail_led_dmi_table);
        } else {
                count = 1;
                pr_err("Skipping DMI detection. "
                       "If the driver works on your hardware please "
                       "report model and the output of dmidecode in tracker "
                       "at http://sourceforge.net/projects/clevo-mailled/\n");
        }

        if (!count)
                return -ENODEV;

        pdev = platform_device_register_simple(KBUILD_MODNAME, -1, NULL, 0);
        if (!IS_ERR(pdev)) {
                error = platform_driver_probe(&clevo_mail_led_driver,
                                              clevo_mail_led_probe);
                if (error) {
                        pr_err("Can't probe platform driver\n");
                        platform_device_unregister(pdev);
                }
        } else
                error = PTR_ERR(pdev);

        return error;
}

static void __exit clevo_mail_led_exit(void)
{
        platform_device_unregister(pdev);
        platform_driver_unregister(&clevo_mail_led_driver);

        clevo_mail_led_set(NULL, LED_OFF);
}

module_init(clevo_mail_led_init);
module_exit(clevo_mail_led_exit);