// SPDX-License-Identifier: GPL-2.0
//
// Driver for TPS65219 Push Button
//
// Copyright (C) 2022 BayLibre Incorporated - https://www.baylibre.com/

#include <linux/init.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/mfd/tps65219.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/slab.h>

struct tps65219_pwrbutton {
        struct device *dev;
        struct input_dev *idev;
        char phys[32];
};

static irqreturn_t tps65219_pb_push_irq(int irq, void *_pwr)
{
        struct tps65219_pwrbutton *pwr = _pwr;

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

        return IRQ_HANDLED;
}

static irqreturn_t tps65219_pb_release_irq(int irq, void *_pwr)
{
        struct tps65219_pwrbutton *pwr = _pwr;

        input_report_key(pwr->idev, KEY_POWER, 0);
        input_sync(pwr->idev);

        return IRQ_HANDLED;
}

static int tps65219_pb_probe(struct platform_device *pdev)
{
        struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent);
        struct device *dev = &pdev->dev;
        struct tps65219_pwrbutton *pwr;
        struct input_dev *idev;
        int error;
        int push_irq;
        int release_irq;

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

        idev = devm_input_allocate_device(dev);
        if (!idev)
                return -ENOMEM;

        idev->name = pdev->name;
        snprintf(pwr->phys, sizeof(pwr->phys), "%s/input0",
                 pdev->name);
        idev->phys = pwr->phys;
        idev->id.bustype = BUS_I2C;

        input_set_capability(idev, EV_KEY, KEY_POWER);

        pwr->dev = dev;
        pwr->idev = idev;
        device_init_wakeup(dev, true);

        push_irq = platform_get_irq(pdev, 0);
        if (push_irq < 0)
                return -EINVAL;

        release_irq = platform_get_irq(pdev, 1);
        if (release_irq < 0)
                return -EINVAL;

        error = devm_request_threaded_irq(dev, push_irq, NULL,
                                          tps65219_pb_push_irq,
                                          IRQF_ONESHOT,
                                          dev->init_name, pwr);
        if (error) {
                dev_err(dev, "failed to request push IRQ #%d: %d\n", push_irq,
                        error);
                return error;
        }

        error = devm_request_threaded_irq(dev, release_irq, NULL,
                                          tps65219_pb_release_irq,
                                          IRQF_ONESHOT,
                                          dev->init_name, pwr);
        if (error) {
                dev_err(dev, "failed to request release IRQ #%d: %d\n",
                        release_irq, error);
                return error;
        }

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

        /* Enable interrupts for the pushbutton */
        regmap_clear_bits(tps->regmap, TPS65219_REG_MASK_CONFIG,
                          TPS65219_REG_MASK_INT_FOR_PB_MASK);

        /* Set PB/EN/VSENSE pin to be a pushbutton */
        regmap_update_bits(tps->regmap, TPS65219_REG_MFP_2_CONFIG,
                           TPS65219_MFP_2_EN_PB_VSENSE_MASK, TPS65219_MFP_2_PB);

        return 0;
}

static void tps65219_pb_remove(struct platform_device *pdev)
{
        struct tps65219 *tps = dev_get_drvdata(pdev->dev.parent);
        int ret;

        /* Disable interrupt for the pushbutton */
        ret = regmap_set_bits(tps->regmap, TPS65219_REG_MASK_CONFIG,
                              TPS65219_REG_MASK_INT_FOR_PB_MASK);
        if (ret)
                dev_warn(&pdev->dev, "Failed to disable irq (%pe)\n", ERR_PTR(ret));
}

static const struct platform_device_id tps65219_pwrbtn_id_table[] = {
        { "tps65219-pwrbutton", },
        { /* sentinel */ }
};
MODULE_DEVICE_TABLE(platform, tps65219_pwrbtn_id_table);

static struct platform_driver tps65219_pb_driver = {
        .probe = tps65219_pb_probe,
        .remove = tps65219_pb_remove,
        .driver = {
                .name = "tps65219_pwrbutton",
        },
        .id_table = tps65219_pwrbtn_id_table,
};
module_platform_driver(tps65219_pb_driver);

MODULE_DESCRIPTION("TPS65219 Power Button");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Markus Schneider-Pargmann <msp@baylibre.com");