/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/input.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/log2.h>
#include <linux/of.h>

#define PON_CNTL_1 0x1C
#define PON_CNTL_PULL_UP BIT(7)
#define PON_CNTL_TRIG_DELAY_MASK (0x7)

/**
 * struct pmic8xxx_pwrkey - pmic8xxx pwrkey information
 * @key_press_irq: key press irq number
 */
struct pmic8xxx_pwrkey {
	int key_press_irq;
};

static irqreturn_t pwrkey_press_irq(int irq, void *_pwr)
{
	struct input_dev *pwr = _pwr;

	input_report_key(pwr, KEY_POWER, 1);
	input_sync(pwr);

	return IRQ_HANDLED;
}

static irqreturn_t pwrkey_release_irq(int irq, void *_pwr)
{
	struct input_dev *pwr = _pwr;

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

	return IRQ_HANDLED;
}

static int __maybe_unused pmic8xxx_pwrkey_suspend(struct device *dev)
{
	struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		enable_irq_wake(pwrkey->key_press_irq);

	return 0;
}

static int __maybe_unused pmic8xxx_pwrkey_resume(struct device *dev)
{
	struct pmic8xxx_pwrkey *pwrkey = dev_get_drvdata(dev);

	if (device_may_wakeup(dev))
		disable_irq_wake(pwrkey->key_press_irq);

	return 0;
}

static SIMPLE_DEV_PM_OPS(pm8xxx_pwr_key_pm_ops,
		pmic8xxx_pwrkey_suspend, pmic8xxx_pwrkey_resume);

static int pmic8xxx_pwrkey_probe(struct platform_device *pdev)
{
	struct input_dev *pwr;
	int key_release_irq = platform_get_irq(pdev, 0);
	int key_press_irq = platform_get_irq(pdev, 1);
	int err;
	unsigned int delay;
	unsigned int pon_cntl;
	struct regmap *regmap;
	struct pmic8xxx_pwrkey *pwrkey;
	u32 kpd_delay;
	bool pull_up;

	if (of_property_read_u32(pdev->dev.of_node, "debounce", &kpd_delay))
		kpd_delay = 15625;

	if (kpd_delay > 62500 || kpd_delay == 0) {
		dev_err(&pdev->dev, "invalid power key trigger delay\n");
		return -EINVAL;
	}

	pull_up = of_property_read_bool(pdev->dev.of_node, "pull-up");

	regmap = dev_get_regmap(pdev->dev.parent, NULL);
	if (!regmap) {
		dev_err(&pdev->dev, "failed to locate regmap for the device\n");
		return -ENODEV;
	}

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

	pwrkey->key_press_irq = key_press_irq;

	pwr = devm_input_allocate_device(&pdev->dev);
	if (!pwr) {
		dev_dbg(&pdev->dev, "Can't allocate power button\n");
		return -ENOMEM;
	}

	input_set_capability(pwr, EV_KEY, KEY_POWER);

	pwr->name = "pmic8xxx_pwrkey";
	pwr->phys = "pmic8xxx_pwrkey/input0";

	delay = (kpd_delay << 10) / USEC_PER_SEC;
	delay = 1 + ilog2(delay);

	err = regmap_read(regmap, PON_CNTL_1, &pon_cntl);
	if (err < 0) {
		dev_err(&pdev->dev, "failed reading PON_CNTL_1 err=%d\n", err);
		return err;
	}

	pon_cntl &= ~PON_CNTL_TRIG_DELAY_MASK;
	pon_cntl |= (delay & PON_CNTL_TRIG_DELAY_MASK);
	if (pull_up)
		pon_cntl |= PON_CNTL_PULL_UP;
	else
		pon_cntl &= ~PON_CNTL_PULL_UP;

	err = regmap_write(regmap, PON_CNTL_1, pon_cntl);
	if (err < 0) {
		dev_err(&pdev->dev, "failed writing PON_CNTL_1 err=%d\n", err);
		return err;
	}

	err = devm_request_irq(&pdev->dev, key_press_irq, pwrkey_press_irq,
			       IRQF_TRIGGER_RISING,
			       "pmic8xxx_pwrkey_press", pwr);
	if (err) {
		dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
			key_press_irq, err);
		return err;
	}

	err = devm_request_irq(&pdev->dev, key_release_irq, pwrkey_release_irq,
			       IRQF_TRIGGER_RISING,
			       "pmic8xxx_pwrkey_release", pwr);
	if (err) {
		dev_err(&pdev->dev, "Can't get %d IRQ for pwrkey: %d\n",
			key_release_irq, err);
		return err;
	}

	err = input_register_device(pwr);
	if (err) {
		dev_err(&pdev->dev, "Can't register power key: %d\n", err);
		return err;
	}

	platform_set_drvdata(pdev, pwrkey);
	device_init_wakeup(&pdev->dev, 1);

	return 0;
}

static int pmic8xxx_pwrkey_remove(struct platform_device *pdev)
{
	device_init_wakeup(&pdev->dev, 0);

	return 0;
}

static const struct of_device_id pm8xxx_pwr_key_id_table[] = {
	{ .compatible = "qcom,pm8058-pwrkey" },
	{ .compatible = "qcom,pm8921-pwrkey" },
	{ }
};
MODULE_DEVICE_TABLE(of, pm8xxx_pwr_key_id_table);

static struct platform_driver pmic8xxx_pwrkey_driver = {
	.probe		= pmic8xxx_pwrkey_probe,
	.remove		= pmic8xxx_pwrkey_remove,
	.driver		= {
		.name	= "pm8xxx-pwrkey",
		.pm	= &pm8xxx_pwr_key_pm_ops,
		.of_match_table = pm8xxx_pwr_key_id_table,
	},
};
module_platform_driver(pmic8xxx_pwrkey_driver);

MODULE_ALIAS("platform:pmic8xxx_pwrkey");
MODULE_DESCRIPTION("PMIC8XXX Power Key driver");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Trilok Soni <tsoni@codeaurora.org>");