// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2014, National Instruments Corp. All rights reserved.
 *
 * Driver for NI Ettus Research USRP E3x0 Button Driver
 */

#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/of.h>
#include <linux/slab.h>

static irqreturn_t e3x0_button_release_handler(int irq, void *data)
{
        struct input_dev *idev = data;

        input_report_key(idev, KEY_POWER, 0);
        input_sync(idev);

        return IRQ_HANDLED;
}

static irqreturn_t e3x0_button_press_handler(int irq, void *data)
{
        struct input_dev *idev = data;

        input_report_key(idev, KEY_POWER, 1);
        pm_wakeup_event(idev->dev.parent, 0);
        input_sync(idev);

        return IRQ_HANDLED;
}

static int e3x0_button_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);

        if (device_may_wakeup(dev))
                enable_irq_wake(platform_get_irq_byname(pdev, "press"));

        return 0;
}

static int e3x0_button_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);

        if (device_may_wakeup(dev))
                disable_irq_wake(platform_get_irq_byname(pdev, "press"));

        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(e3x0_button_pm_ops,
                                e3x0_button_suspend, e3x0_button_resume);

static int e3x0_button_probe(struct platform_device *pdev)
{
        struct input_dev *input;
        int irq_press, irq_release;
        int error;

        irq_press = platform_get_irq_byname(pdev, "press");
        if (irq_press < 0)
                return irq_press;

        irq_release = platform_get_irq_byname(pdev, "release");
        if (irq_release < 0)
                return irq_release;

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

        input->name = "NI Ettus Research USRP E3x0 Button Driver";
        input->phys = "e3x0_button/input0";
        input->dev.parent = &pdev->dev;

        input_set_capability(input, EV_KEY, KEY_POWER);

        error = devm_request_irq(&pdev->dev, irq_press,
                                 e3x0_button_press_handler, 0,
                                 "e3x0-button", input);
        if (error) {
                dev_err(&pdev->dev, "Failed to request 'press' IRQ#%d: %d\n",
                        irq_press, error);
                return error;
        }

        error = devm_request_irq(&pdev->dev, irq_release,
                                 e3x0_button_release_handler, 0,
                                 "e3x0-button", input);
        if (error) {
                dev_err(&pdev->dev, "Failed to request 'release' IRQ#%d: %d\n",
                        irq_release, error);
                return error;
        }

        error = input_register_device(input);
        if (error) {
                dev_err(&pdev->dev, "Can't register input device: %d\n", error);
                return error;
        }

        device_init_wakeup(&pdev->dev, 1);
        return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id e3x0_button_match[] = {
        { .compatible = "ettus,e3x0-button", },
        { }
};
MODULE_DEVICE_TABLE(of, e3x0_button_match);
#endif

static struct platform_driver e3x0_button_driver = {
        .driver         = {
                .name   = "e3x0-button",
                .of_match_table = of_match_ptr(e3x0_button_match),
                .pm     = pm_sleep_ptr(&e3x0_button_pm_ops),
        },
        .probe          = e3x0_button_probe,
};

module_platform_driver(e3x0_button_driver);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Moritz Fischer <moritz.fischer@ettus.com>");
MODULE_DESCRIPTION("NI Ettus Research USRP E3x0 Button driver");
MODULE_ALIAS("platform:e3x0-button");