// SPDX-License-Identifier: GPL-2.0
// Copyright (C) STMicroelectronics 2018
// Author: Pascal Paillet <p.paillet@st.com> for STMicroelectronics.

#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/mfd/stpmic1.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/property.h>
#include <linux/regmap.h>

/**
 * struct stpmic1_onkey - OnKey data
 * @input_dev:          pointer to input device
 * @irq_falling:        irq that we are hooked on to
 * @irq_rising:         irq that we are hooked on to
 */
struct stpmic1_onkey {
        struct input_dev *input_dev;
        int irq_falling;
        int irq_rising;
};

static irqreturn_t onkey_falling_irq(int irq, void *ponkey)
{
        struct stpmic1_onkey *onkey = ponkey;
        struct input_dev *input_dev = onkey->input_dev;

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

        return IRQ_HANDLED;
}

static irqreturn_t onkey_rising_irq(int irq, void *ponkey)
{
        struct stpmic1_onkey *onkey = ponkey;
        struct input_dev *input_dev = onkey->input_dev;

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

        return IRQ_HANDLED;
}

static int stpmic1_onkey_probe(struct platform_device *pdev)
{
        struct stpmic1 *pmic = dev_get_drvdata(pdev->dev.parent);
        struct device *dev = &pdev->dev;
        struct input_dev *input_dev;
        struct stpmic1_onkey *onkey;
        unsigned int val, reg = 0;
        int error;

        onkey = devm_kzalloc(dev, sizeof(*onkey), GFP_KERNEL);
        if (!onkey)
                return -ENOMEM;

        onkey->irq_falling = platform_get_irq_byname(pdev, "onkey-falling");
        if (onkey->irq_falling < 0)
                return onkey->irq_falling;

        onkey->irq_rising = platform_get_irq_byname(pdev, "onkey-rising");
        if (onkey->irq_rising < 0)
                return onkey->irq_rising;

        if (!device_property_read_u32(dev, "power-off-time-sec", &val)) {
                if (val > 0 && val <= 16) {
                        dev_dbg(dev, "power-off-time=%d seconds\n", val);
                        reg |= PONKEY_PWR_OFF;
                        reg |= ((16 - val) & PONKEY_TURNOFF_TIMER_MASK);
                } else {
                        dev_err(dev, "power-off-time-sec out of range\n");
                        return -EINVAL;
                }
        }

        if (device_property_present(dev, "st,onkey-clear-cc-flag"))
                reg |= PONKEY_CC_FLAG_CLEAR;

        error = regmap_update_bits(pmic->regmap, PKEY_TURNOFF_CR,
                                   PONKEY_TURNOFF_MASK, reg);
        if (error) {
                dev_err(dev, "PKEY_TURNOFF_CR write failed: %d\n", error);
                return error;
        }

        if (device_property_present(dev, "st,onkey-pu-inactive")) {
                error = regmap_update_bits(pmic->regmap, PADS_PULL_CR,
                                           PONKEY_PU_INACTIVE,
                                           PONKEY_PU_INACTIVE);
                if (error) {
                        dev_err(dev, "ONKEY Pads configuration failed: %d\n",
                                error);
                        return error;
                }
        }

        input_dev = devm_input_allocate_device(dev);
        if (!input_dev) {
                dev_err(dev, "Can't allocate Pwr Onkey Input Device\n");
                return -ENOMEM;
        }

        input_dev->name = "pmic_onkey";
        input_dev->phys = "pmic_onkey/input0";

        input_set_capability(input_dev, EV_KEY, KEY_POWER);

        onkey->input_dev = input_dev;

        /* interrupt is nested in a thread */
        error = devm_request_threaded_irq(dev, onkey->irq_falling, NULL,
                                          onkey_falling_irq, IRQF_ONESHOT,
                                          dev_name(dev), onkey);
        if (error) {
                dev_err(dev, "Can't get IRQ Onkey Falling: %d\n", error);
                return error;
        }

        error = devm_request_threaded_irq(dev, onkey->irq_rising, NULL,
                                          onkey_rising_irq, IRQF_ONESHOT,
                                          dev_name(dev), onkey);
        if (error) {
                dev_err(dev, "Can't get IRQ Onkey Rising: %d\n", error);
                return error;
        }

        error = input_register_device(input_dev);
        if (error) {
                dev_err(dev, "Can't register power button: %d\n", error);
                return error;
        }

        platform_set_drvdata(pdev, onkey);
        device_init_wakeup(dev, true);

        return 0;
}

static int stpmic1_onkey_suspend(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct stpmic1_onkey *onkey = platform_get_drvdata(pdev);

        if (device_may_wakeup(dev)) {
                enable_irq_wake(onkey->irq_falling);
                enable_irq_wake(onkey->irq_rising);
        }
        return 0;
}

static int stpmic1_onkey_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct stpmic1_onkey *onkey = platform_get_drvdata(pdev);

        if (device_may_wakeup(dev)) {
                disable_irq_wake(onkey->irq_falling);
                disable_irq_wake(onkey->irq_rising);
        }
        return 0;
}

static DEFINE_SIMPLE_DEV_PM_OPS(stpmic1_onkey_pm,
                                stpmic1_onkey_suspend,
                                stpmic1_onkey_resume);

static const struct of_device_id of_stpmic1_onkey_match[] = {
        { .compatible = "st,stpmic1-onkey" },
        { },
};

MODULE_DEVICE_TABLE(of, of_stpmic1_onkey_match);

static struct platform_driver stpmic1_onkey_driver = {
        .probe  = stpmic1_onkey_probe,
        .driver = {
                .name   = "stpmic1_onkey",
                .of_match_table = of_match_ptr(of_stpmic1_onkey_match),
                .pm     = pm_sleep_ptr(&stpmic1_onkey_pm),
        },
};
module_platform_driver(stpmic1_onkey_driver);

MODULE_DESCRIPTION("Onkey driver for STPMIC1");
MODULE_AUTHOR("Pascal Paillet <p.paillet@st.com>");
MODULE_LICENSE("GPL v2");