// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Generic GPIO beeper driver
 *
 * Copyright (C) 2013-2014 Alexander Shiyan <shc_work@mail.ru>
 */

#include <linux/input.h>
#include <linux/module.h>
#include <linux/gpio/consumer.h>
#include <linux/of.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>

#define BEEPER_MODNAME          "gpio-beeper"

struct gpio_beeper {
        struct work_struct      work;
        struct gpio_desc        *desc;
        bool                    beeping;
};

static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on)
{
        gpiod_set_value_cansleep(beep->desc, on);
}

static void gpio_beeper_work(struct work_struct *work)
{
        struct gpio_beeper *beep = container_of(work, struct gpio_beeper, work);

        gpio_beeper_toggle(beep, beep->beeping);
}

static int gpio_beeper_event(struct input_dev *dev, unsigned int type,
                             unsigned int code, int value)
{
        struct gpio_beeper *beep = input_get_drvdata(dev);

        if (type != EV_SND || code != SND_BELL)
                return -ENOTSUPP;

        if (value < 0)
                return -EINVAL;

        beep->beeping = value;
        /* Schedule work to actually turn the beeper on or off */
        schedule_work(&beep->work);

        return 0;
}

static void gpio_beeper_close(struct input_dev *input)
{
        struct gpio_beeper *beep = input_get_drvdata(input);

        cancel_work_sync(&beep->work);
        gpio_beeper_toggle(beep, false);
}

static int gpio_beeper_probe(struct platform_device *pdev)
{
        struct gpio_beeper *beep;
        struct input_dev *input;

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

        beep->desc = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW);
        if (IS_ERR(beep->desc))
                return PTR_ERR(beep->desc);

        input = devm_input_allocate_device(&pdev->dev);
        if (!input)
                return -ENOMEM;

        INIT_WORK(&beep->work, gpio_beeper_work);

        input->name             = pdev->name;
        input->id.bustype       = BUS_HOST;
        input->id.vendor        = 0x0001;
        input->id.product       = 0x0001;
        input->id.version       = 0x0100;
        input->close            = gpio_beeper_close;
        input->event            = gpio_beeper_event;

        input_set_capability(input, EV_SND, SND_BELL);

        input_set_drvdata(input, beep);

        return input_register_device(input);
}

#ifdef CONFIG_OF
static const struct of_device_id gpio_beeper_of_match[] = {
        { .compatible = "gpio-beeper", },
        { }
};
MODULE_DEVICE_TABLE(of, gpio_beeper_of_match);
#endif

static struct platform_driver gpio_beeper_platform_driver = {
        .driver = {
                .name           = BEEPER_MODNAME,
                .of_match_table = of_match_ptr(gpio_beeper_of_match),
        },
        .probe  = gpio_beeper_probe,
};
module_platform_driver(gpio_beeper_platform_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("Generic GPIO beeper driver");