/* 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/input/pmic8xxx-pwrkey.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;
  }
  
  #ifdef CONFIG_PM_SLEEP
  static int 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 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;
  }
  #endif
  
  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;
  	const struct pm8xxx_pwrkey_platform_data *pdata =
  					dev_get_platdata(&pdev->dev);
  
  	if (!pdata) {
  		dev_err(&pdev->dev, "power key platform data not supplied
  ");
  		return -EINVAL;
  	}
  
  	if (pdata->kpd_trigger_delay_us > 62500) {
  		dev_err(&pdev->dev, "invalid power key trigger delay
  ");
  		return -EINVAL;
  	}
  
  	regmap = dev_get_regmap(pdev->dev.parent, NULL);
  	if (!regmap) {
  		dev_err(&pdev->dev, "failed to locate regmap for the device
  ");
  		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
  ");
  		return -ENOMEM;
  	}
  
  	input_set_capability(pwr, EV_KEY, KEY_POWER);
  
  	pwr->name = "pmic8xxx_pwrkey";
  	pwr->phys = "pmic8xxx_pwrkey/input0";
  
  	delay = (pdata->kpd_trigger_delay_us << 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
  ", err);
  		return err;
  	}
  
  	pon_cntl &= ~PON_CNTL_TRIG_DELAY_MASK;
  	pon_cntl |= (delay & PON_CNTL_TRIG_DELAY_MASK);
  	if (pdata->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
  ", 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
  ",
  			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
  ",
  			key_release_irq, err);
  		return err;
  	}
  
  	err = input_register_device(pwr);
  	if (err) {
  		dev_err(&pdev->dev, "Can't register power key: %d
  ", err);
  		return err;
  	}
  
  	platform_set_drvdata(pdev, pwrkey);
  	device_init_wakeup(&pdev->dev, pdata->wakeup);
  
  	return 0;
  }
  
  static int pmic8xxx_pwrkey_remove(struct platform_device *pdev)
  {
  	device_init_wakeup(&pdev->dev, 0);
  
  	return 0;
  }
  
  static struct platform_driver pmic8xxx_pwrkey_driver = {
  	.probe		= pmic8xxx_pwrkey_probe,
  	.remove		= pmic8xxx_pwrkey_remove,
  	.driver		= {
  		.name	= PM8XXX_PWRKEY_DEV_NAME,
  		.owner	= THIS_MODULE,
  		.pm	= &pm8xxx_pwr_key_pm_ops,
  	},
  };
  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>");