/*
   * OnKey device driver for DA9063 and DA9062 PMICs
   * Copyright (C) 2015  Dialog Semiconductor Ltd.
   *
   * This program is free software; you can redistribute it and/or
   * modify it under the terms of the GNU General Public License
   * as published by the Free Software Foundation; either version 2
   * of the License, or (at your option) any later version.
   *
   * 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/errno.h>
  #include <linux/input.h>
  #include <linux/interrupt.h>
  #include <linux/platform_device.h>
  #include <linux/workqueue.h>
  #include <linux/regmap.h>
  #include <linux/of.h>
  #include <linux/mfd/da9063/core.h>
  #include <linux/mfd/da9063/pdata.h>
  #include <linux/mfd/da9063/registers.h>
  #include <linux/mfd/da9062/core.h>
  #include <linux/mfd/da9062/registers.h>
  
  struct da906x_chip_config {
  	/* REGS */
  	int onkey_status;
  	int onkey_pwr_signalling;
  	int onkey_fault_log;
  	int onkey_shutdown;
  	/* MASKS */
  	int onkey_nonkey_mask;
  	int onkey_nonkey_lock_mask;
  	int onkey_key_reset_mask;
  	int onkey_shutdown_mask;
  	/* NAMES */
  	const char *name;
  };
  
  struct da9063_onkey {
  	struct delayed_work work;
  	struct input_dev *input;
  	struct device *dev;
  	struct regmap *regmap;
  	const struct da906x_chip_config *config;
  	char phys[32];
  	bool key_power;
  };
  
  static const struct da906x_chip_config da9063_regs = {
  	/* REGS */
  	.onkey_status = DA9063_REG_STATUS_A,
  	.onkey_pwr_signalling = DA9063_REG_CONTROL_B,
  	.onkey_fault_log = DA9063_REG_FAULT_LOG,
  	.onkey_shutdown = DA9063_REG_CONTROL_F,
  	/* MASKS */
  	.onkey_nonkey_mask = DA9063_NONKEY,
  	.onkey_nonkey_lock_mask = DA9063_NONKEY_LOCK,
  	.onkey_key_reset_mask = DA9063_KEY_RESET,
  	.onkey_shutdown_mask = DA9063_SHUTDOWN,
  	/* NAMES */
  	.name = DA9063_DRVNAME_ONKEY,
  };
  
  static const struct da906x_chip_config da9062_regs = {
  	/* REGS */
  	.onkey_status = DA9062AA_STATUS_A,
  	.onkey_pwr_signalling = DA9062AA_CONTROL_B,
  	.onkey_fault_log = DA9062AA_FAULT_LOG,
  	.onkey_shutdown = DA9062AA_CONTROL_F,
  	/* MASKS */
  	.onkey_nonkey_mask = DA9062AA_NONKEY_MASK,
  	.onkey_nonkey_lock_mask = DA9062AA_NONKEY_LOCK_MASK,
  	.onkey_key_reset_mask = DA9062AA_KEY_RESET_MASK,
  	.onkey_shutdown_mask = DA9062AA_SHUTDOWN_MASK,
  	/* NAMES */
  	.name = "da9062-onkey",
  };
  
  static const struct of_device_id da9063_compatible_reg_id_table[] = {
  	{ .compatible = "dlg,da9063-onkey", .data = &da9063_regs },
  	{ .compatible = "dlg,da9062-onkey", .data = &da9062_regs },
  	{ },
  };
  
  static void da9063_poll_on(struct work_struct *work)
  {
  	struct da9063_onkey *onkey = container_of(work,
  						struct da9063_onkey,
  						work.work);
  	const struct da906x_chip_config *config = onkey->config;
  	unsigned int val;
  	int fault_log = 0;
  	bool poll = true;
  	int error;
  
  	/* Poll to see when the pin is released */
  	error = regmap_read(onkey->regmap,
  			    config->onkey_status,
  			    &val);
  	if (error) {
  		dev_err(onkey->dev,
  			"Failed to read ON status: %d
  ", error);
  		goto err_poll;
  	}
  
  	if (!(val & config->onkey_nonkey_mask)) {
  		error = regmap_update_bits(onkey->regmap,
  					   config->onkey_pwr_signalling,
  					   config->onkey_nonkey_lock_mask,
  					   0);
  		if (error) {
  			dev_err(onkey->dev,
  				"Failed to reset the Key Delay %d
  ", error);
  			goto err_poll;
  		}
  
  		input_report_key(onkey->input, KEY_POWER, 0);
  		input_sync(onkey->input);
  
  		poll = false;
  	}
  
  	/*
  	 * If the fault log KEY_RESET is detected, then clear it
  	 * and shut down the system.
  	 */
  	error = regmap_read(onkey->regmap,
  			    config->onkey_fault_log,
  			    &fault_log);
  	if (error) {
  		dev_warn(&onkey->input->dev,
  			 "Cannot read FAULT_LOG: %d
  ", error);
  	} else if (fault_log & config->onkey_key_reset_mask) {
  		error = regmap_write(onkey->regmap,
  				     config->onkey_fault_log,
  				     config->onkey_key_reset_mask);
  		if (error) {
  			dev_warn(&onkey->input->dev,
  				 "Cannot reset KEY_RESET fault log: %d
  ",
  				 error);
  		} else {
  			/* at this point we do any S/W housekeeping
  			 * and then send shutdown command
  			 */
  			dev_dbg(&onkey->input->dev,
  				"Sending SHUTDOWN to DA9063 ...
  ");
  			error = regmap_write(onkey->regmap,
  					     config->onkey_shutdown,
  					     config->onkey_shutdown_mask);
  			if (error)
  				dev_err(&onkey->input->dev,
  					"Cannot SHUTDOWN DA9063: %d
  ",
  					error);
  		}
  	}
  
  err_poll:
  	if (poll)
  		schedule_delayed_work(&onkey->work, msecs_to_jiffies(50));
  }
  
  static irqreturn_t da9063_onkey_irq_handler(int irq, void *data)
  {
  	struct da9063_onkey *onkey = data;
  	const struct da906x_chip_config *config = onkey->config;
  	unsigned int val;
  	int error;
  
  	error = regmap_read(onkey->regmap,
  			    config->onkey_status,
  			    &val);
  	if (onkey->key_power && !error && (val & config->onkey_nonkey_mask)) {
  		input_report_key(onkey->input, KEY_POWER, 1);
  		input_sync(onkey->input);
  		schedule_delayed_work(&onkey->work, 0);
  		dev_dbg(onkey->dev, "KEY_POWER pressed.
  ");
  	} else {
  		input_report_key(onkey->input, KEY_SLEEP, 1);
  		input_sync(onkey->input);
  		input_report_key(onkey->input, KEY_SLEEP, 0);
  		input_sync(onkey->input);
  		dev_dbg(onkey->dev, "KEY_SLEEP pressed.
  ");
  	}
  
  	return IRQ_HANDLED;
  }
  
  static void da9063_cancel_poll(void *data)
  {
  	struct da9063_onkey *onkey = data;
  
  	cancel_delayed_work_sync(&onkey->work);
  }
  
  static int da9063_onkey_probe(struct platform_device *pdev)
  {
  	struct da9063 *da9063 = dev_get_drvdata(pdev->dev.parent);
  	struct da9063_pdata *pdata = dev_get_platdata(da9063->dev);
  	struct da9063_onkey *onkey;
  	const struct of_device_id *match;
  	int irq;
  	int error;
  
  	match = of_match_node(da9063_compatible_reg_id_table,
  			      pdev->dev.of_node);
  	if (!match)
  		return -ENXIO;
  
  	onkey = devm_kzalloc(&pdev->dev, sizeof(struct da9063_onkey),
  			     GFP_KERNEL);
  	if (!onkey) {
  		dev_err(&pdev->dev, "Failed to allocate memory.
  ");
  		return -ENOMEM;
  	}
  
  	onkey->config = match->data;
  	onkey->dev = &pdev->dev;
  
  	onkey->regmap = dev_get_regmap(pdev->dev.parent, NULL);
  	if (!onkey->regmap) {
  		dev_err(&pdev->dev, "Parent regmap unavailable.
  ");
  		return -ENXIO;
  	}
  
  	if (pdata)
  		onkey->key_power = pdata->key_power;
  	else
  		onkey->key_power =
  			!of_property_read_bool(pdev->dev.of_node,
  					       "dlg,disable-key-power");
  
  	onkey->input = devm_input_allocate_device(&pdev->dev);
  	if (!onkey->input) {
  		dev_err(&pdev->dev, "Failed to allocated input device.
  ");
  		return -ENOMEM;
  	}
  
  	onkey->input->name = onkey->config->name;
  	snprintf(onkey->phys, sizeof(onkey->phys), "%s/input0",
  		 onkey->config->name);
  	onkey->input->phys = onkey->phys;
  	onkey->input->dev.parent = &pdev->dev;
  
  	if (onkey->key_power)
  		input_set_capability(onkey->input, EV_KEY, KEY_POWER);
  
  	input_set_capability(onkey->input, EV_KEY, KEY_SLEEP);
  
  	INIT_DELAYED_WORK(&onkey->work, da9063_poll_on);
  
  	error = devm_add_action(&pdev->dev, da9063_cancel_poll, onkey);
  	if (error) {
  		dev_err(&pdev->dev,
  			"Failed to add cancel poll action: %d
  ",
  			error);
  		return error;
  	}
  
  	irq = platform_get_irq_byname(pdev, "ONKEY");
  	if (irq < 0) {
  		error = irq;
  		dev_err(&pdev->dev, "Failed to get platform IRQ: %d
  ", error);
  		return error;
  	}
  
  	error = devm_request_threaded_irq(&pdev->dev, irq,
  					  NULL, da9063_onkey_irq_handler,
  					  IRQF_TRIGGER_LOW | IRQF_ONESHOT,
  					  "ONKEY", onkey);
  	if (error) {
  		dev_err(&pdev->dev,
  			"Failed to request IRQ %d: %d
  ", irq, error);
  		return error;
  	}
  
  	error = input_register_device(onkey->input);
  	if (error) {
  		dev_err(&pdev->dev,
  			"Failed to register input device: %d
  ", error);
  		return error;
  	}
  
  	platform_set_drvdata(pdev, onkey);
  	return 0;
  }
  
  static struct platform_driver da9063_onkey_driver = {
  	.probe	= da9063_onkey_probe,
  	.driver	= {
  		.name	= DA9063_DRVNAME_ONKEY,
  		.of_match_table = da9063_compatible_reg_id_table,
  	},
  };
  module_platform_driver(da9063_onkey_driver);
  
  MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
  MODULE_DESCRIPTION("Onkey device driver for Dialog DA9063 and DA9062");
  MODULE_LICENSE("GPL");
  MODULE_ALIAS("platform:" DA9063_DRVNAME_ONKEY);