// SPDX-License-Identifier: GPL-2.0
//
// Copyright (C) 2018 BayLibre SAS
// Author: Bartosz Golaszewski <bgolaszewski@baylibre.com>
//
// ONKEY driver for MAXIM 77650/77651 charger/power-supply.

#include <linux/i2c.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/mfd/max77650.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>

#define MAX77650_ONKEY_MODE_MASK        BIT(3)
#define MAX77650_ONKEY_MODE_PUSH        0x00
#define MAX77650_ONKEY_MODE_SLIDE       BIT(3)

struct max77650_onkey {
        struct input_dev *input;
        unsigned int code;
};

static irqreturn_t max77650_onkey_falling(int irq, void *data)
{
        struct max77650_onkey *onkey = data;

        input_report_key(onkey->input, onkey->code, 0);
        input_sync(onkey->input);

        return IRQ_HANDLED;
}

static irqreturn_t max77650_onkey_rising(int irq, void *data)
{
        struct max77650_onkey *onkey = data;

        input_report_key(onkey->input, onkey->code, 1);
        input_sync(onkey->input);

        return IRQ_HANDLED;
}

static int max77650_onkey_probe(struct platform_device *pdev)
{
        int irq_r, irq_f, error, mode;
        struct max77650_onkey *onkey;
        struct device *dev, *parent;
        struct regmap *map;
        unsigned int type;

        dev = &pdev->dev;
        parent = dev->parent;

        map = dev_get_regmap(parent, NULL);
        if (!map)
                return -ENODEV;

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

        error = device_property_read_u32(dev, "linux,code", &onkey->code);
        if (error)
                onkey->code = KEY_POWER;

        if (device_property_read_bool(dev, "maxim,onkey-slide")) {
                mode = MAX77650_ONKEY_MODE_SLIDE;
                type = EV_SW;
        } else {
                mode = MAX77650_ONKEY_MODE_PUSH;
                type = EV_KEY;
        }

        error = regmap_update_bits(map, MAX77650_REG_CNFG_GLBL,
                                   MAX77650_ONKEY_MODE_MASK, mode);
        if (error)
                return error;

        irq_f = platform_get_irq_byname(pdev, "nEN_F");
        if (irq_f < 0)
                return irq_f;

        irq_r = platform_get_irq_byname(pdev, "nEN_R");
        if (irq_r < 0)
                return irq_r;

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

        onkey->input->name = "max77650_onkey";
        onkey->input->phys = "max77650_onkey/input0";
        onkey->input->id.bustype = BUS_I2C;
        input_set_capability(onkey->input, type, onkey->code);

        error = devm_request_any_context_irq(dev, irq_f, max77650_onkey_falling,
                                             IRQF_ONESHOT, "onkey-down", onkey);
        if (error < 0)
                return error;

        error = devm_request_any_context_irq(dev, irq_r, max77650_onkey_rising,
                                             IRQF_ONESHOT, "onkey-up", onkey);
        if (error < 0)
                return error;

        return input_register_device(onkey->input);
}

static const struct of_device_id max77650_onkey_of_match[] = {
        { .compatible = "maxim,max77650-onkey" },
        { }
};
MODULE_DEVICE_TABLE(of, max77650_onkey_of_match);

static struct platform_driver max77650_onkey_driver = {
        .driver = {
                .name = "max77650-onkey",
                .of_match_table = max77650_onkey_of_match,
        },
        .probe = max77650_onkey_probe,
};
module_platform_driver(max77650_onkey_driver);

MODULE_DESCRIPTION("MAXIM 77650/77651 ONKEY driver");
MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:max77650-onkey");