// SPDX-License-Identifier: GPL-2.0-only
/*
 * CPCAP Power Button Input Driver
 *
 * Copyright (C) 2017 Sebastian Reichel <sre@kernel.org>
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/regmap.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/mfd/motorola-cpcap.h>

#define CPCAP_IRQ_ON 23
#define CPCAP_IRQ_ON_BITMASK (1 << (CPCAP_IRQ_ON % 16))

struct cpcap_power_button {
        struct regmap *regmap;
        struct input_dev *idev;
        struct device *dev;
};

static irqreturn_t powerbutton_irq(int irq, void *_button)
{
        struct cpcap_power_button *button = _button;
        int val;

        val = cpcap_sense_virq(button->regmap, irq);
        if (val < 0) {
                dev_err(button->dev, "irq read failed: %d", val);
                return IRQ_HANDLED;
        }

        pm_wakeup_event(button->dev, 0);
        input_report_key(button->idev, KEY_POWER, val);
        input_sync(button->idev);

        return IRQ_HANDLED;
}

static int cpcap_power_button_probe(struct platform_device *pdev)
{
        struct cpcap_power_button *button;
        int irq;
        int err;

        irq = platform_get_irq(pdev, 0);
        if (irq < 0)
                return irq;

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

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

        button->regmap = dev_get_regmap(pdev->dev.parent, NULL);
        if (!button->regmap)
                return -ENODEV;

        button->dev = &pdev->dev;

        button->idev->name = "cpcap-pwrbutton";
        button->idev->phys = "cpcap-pwrbutton/input0";
        input_set_capability(button->idev, EV_KEY, KEY_POWER);

        err = devm_request_threaded_irq(&pdev->dev, irq, NULL,
                powerbutton_irq, IRQF_ONESHOT, "cpcap_pwrbutton", button);
        if (err < 0) {
                dev_err(&pdev->dev, "IRQ request failed: %d\n", err);
                return err;
        }

        err = input_register_device(button->idev);
        if (err) {
                dev_err(&pdev->dev, "Input register failed: %d\n", err);
                return err;
        }

        device_init_wakeup(&pdev->dev, true);

        return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id cpcap_pwrbutton_dt_match_table[] = {
        { .compatible = "motorola,cpcap-pwrbutton" },
        {},
};
MODULE_DEVICE_TABLE(of, cpcap_pwrbutton_dt_match_table);
#endif

static struct platform_driver cpcap_power_button_driver = {
        .probe          = cpcap_power_button_probe,
        .driver         = {
                .name   = "cpcap-pwrbutton",
                .of_match_table = of_match_ptr(cpcap_pwrbutton_dt_match_table),
        },
};
module_platform_driver(cpcap_power_button_driver);

MODULE_ALIAS("platform:cpcap-pwrbutton");
MODULE_DESCRIPTION("CPCAP Power Button");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Sebastian Reichel <sre@kernel.org>");