/*

   *  button.c - ACPI Button Driver

   *
   *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   *
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   *
   *  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.
   *
   *  You should have received a copy of the GNU General Public License along
   *  with this program; if not, write to the Free Software Foundation, Inc.,
   *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
   *
   * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   */
  
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/init.h>

  #include <linux/types.h>
  #include <linux/proc_fs.h>
  #include <linux/seq_file.h>

  #include <linux/input.h>

  #include <linux/slab.h>

  #include <acpi/acpi_bus.h>
  #include <acpi/acpi_drivers.h>

  #define PREFIX "ACPI: "

  #define ACPI_BUTTON_CLASS		"button"

  #define ACPI_BUTTON_FILE_INFO		"info"
  #define ACPI_BUTTON_FILE_STATE		"state"
  #define ACPI_BUTTON_TYPE_UNKNOWN	0x00

  #define ACPI_BUTTON_NOTIFY_STATUS	0x80
  
  #define ACPI_BUTTON_SUBCLASS_POWER	"power"

  #define ACPI_BUTTON_HID_POWER		"PNP0C0C"

  #define ACPI_BUTTON_DEVICE_NAME_POWER	"Power Button"

  #define ACPI_BUTTON_TYPE_POWER		0x01

  
  #define ACPI_BUTTON_SUBCLASS_SLEEP	"sleep"
  #define ACPI_BUTTON_HID_SLEEP		"PNP0C0E"

  #define ACPI_BUTTON_DEVICE_NAME_SLEEP	"Sleep Button"

  #define ACPI_BUTTON_TYPE_SLEEP		0x03

  
  #define ACPI_BUTTON_SUBCLASS_LID	"lid"
  #define ACPI_BUTTON_HID_LID		"PNP0C0D"
  #define ACPI_BUTTON_DEVICE_NAME_LID	"Lid Switch"
  #define ACPI_BUTTON_TYPE_LID		0x05
  
  #define _COMPONENT		ACPI_BUTTON_COMPONENT

  ACPI_MODULE_NAME("button");

  MODULE_AUTHOR("Paul Diefenbaugh");

  MODULE_DESCRIPTION("ACPI Button Driver");

  MODULE_LICENSE("GPL");

  static const struct acpi_device_id button_device_ids[] = {
  	{ACPI_BUTTON_HID_LID,    0},
  	{ACPI_BUTTON_HID_SLEEP,  0},
  	{ACPI_BUTTON_HID_SLEEPF, 0},
  	{ACPI_BUTTON_HID_POWER,  0},
  	{ACPI_BUTTON_HID_POWERF, 0},
  	{"", 0},
  };
  MODULE_DEVICE_TABLE(acpi, button_device_ids);

  static int acpi_button_add(struct acpi_device *device);
  static int acpi_button_remove(struct acpi_device *device, int type);

  static int acpi_button_resume(struct acpi_device *device);

  static void acpi_button_notify(struct acpi_device *device, u32 event);

  
  static struct acpi_driver acpi_button_driver = {

  	.name = "button",

  	.class = ACPI_BUTTON_CLASS,

  	.ids = button_device_ids,

  	.ops = {
  		.add = acpi_button_add,

  		.resume = acpi_button_resume,

  		.remove = acpi_button_remove,

  		.notify = acpi_button_notify,

  	},

  };
  
  struct acpi_button {

  	unsigned int type;
  	struct input_dev *input;
  	char phys[32];			/* for input device */

  	unsigned long pushed;

  	bool wakeup_enabled;

  };

  static BLOCKING_NOTIFIER_HEAD(acpi_lid_notifier);
  static struct acpi_device *lid_device;

  /* --------------------------------------------------------------------------
                                FS Interface (/proc)
     -------------------------------------------------------------------------- */

  static struct proc_dir_entry *acpi_button_dir;

  static struct proc_dir_entry *acpi_lid_dir;

  static int acpi_button_state_seq_show(struct seq_file *seq, void *offset)
  {

  	struct acpi_device *device = seq->private;

  	acpi_status status;

  	unsigned long long state;

  	status = acpi_evaluate_integer(device->handle, "_LID", NULL, &state);

  	seq_printf(seq, "state:      %s
  ",
  		   ACPI_FAILURE(status) ? "unsupported" :
  			(state ? "open" : "closed"));

  	return 0;

  }
  
  static int acpi_button_state_open_fs(struct inode *inode, struct file *file)
  {
  	return single_open(file, acpi_button_state_seq_show, PDE(inode)->data);
  }

  static const struct file_operations acpi_button_state_fops = {
  	.owner = THIS_MODULE,
  	.open = acpi_button_state_open_fs,
  	.read = seq_read,
  	.llseek = seq_lseek,
  	.release = single_release,
  };

  static int acpi_button_add_fs(struct acpi_device *device)

  {

  	struct acpi_button *button = acpi_driver_data(device);

  	struct proc_dir_entry *entry = NULL;

  	int ret = 0;

  	/* procfs I/F for ACPI lid device only */
  	if (button->type != ACPI_BUTTON_TYPE_LID)
  		return 0;
  
  	if (acpi_button_dir || acpi_lid_dir) {
  		printk(KERN_ERR PREFIX "More than one Lid device found!
  ");
  		return -EEXIST;

  	}

  	/* create /proc/acpi/button */
  	acpi_button_dir = proc_mkdir(ACPI_BUTTON_CLASS, acpi_root_dir);
  	if (!acpi_button_dir)

  		return -ENODEV;

  	/* create /proc/acpi/button/lid */
  	acpi_lid_dir = proc_mkdir(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
  	if (!acpi_lid_dir) {
  		ret = -ENODEV;
  		goto remove_button_dir;
  	}

  	/* create /proc/acpi/button/lid/LID/ */
  	acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device), acpi_lid_dir);
  	if (!acpi_device_dir(device)) {
  		ret = -ENODEV;
  		goto remove_lid_dir;
  	}

  	/* create /proc/acpi/button/lid/LID/state */
  	entry = proc_create_data(ACPI_BUTTON_FILE_STATE,
  				 S_IRUGO, acpi_device_dir(device),
  				 &acpi_button_state_fops, device);
  	if (!entry) {
  		ret = -ENODEV;
  		goto remove_dev_dir;

  	}

  done:
  	return ret;
  
  remove_dev_dir:
  	remove_proc_entry(acpi_device_bid(device),
  			  acpi_lid_dir);
  	acpi_device_dir(device) = NULL;
  remove_lid_dir:
  	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
  remove_button_dir:
  	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);
  	goto done;

  }

  static int acpi_button_remove_fs(struct acpi_device *device)

  {

  	struct acpi_button *button = acpi_driver_data(device);

  	if (button->type != ACPI_BUTTON_TYPE_LID)
  		return 0;

  	remove_proc_entry(ACPI_BUTTON_FILE_STATE,
  			  acpi_device_dir(device));
  	remove_proc_entry(acpi_device_bid(device),
  			  acpi_lid_dir);
  	acpi_device_dir(device) = NULL;
  	remove_proc_entry(ACPI_BUTTON_SUBCLASS_LID, acpi_button_dir);
  	remove_proc_entry(ACPI_BUTTON_CLASS, acpi_root_dir);

  	return 0;

  }

  /* --------------------------------------------------------------------------
                                  Driver Interface
     -------------------------------------------------------------------------- */

  int acpi_lid_notifier_register(struct notifier_block *nb)
  {
  	return blocking_notifier_chain_register(&acpi_lid_notifier, nb);
  }
  EXPORT_SYMBOL(acpi_lid_notifier_register);
  
  int acpi_lid_notifier_unregister(struct notifier_block *nb)
  {
  	return blocking_notifier_chain_unregister(&acpi_lid_notifier, nb);
  }
  EXPORT_SYMBOL(acpi_lid_notifier_unregister);
  
  int acpi_lid_open(void)
  {
  	acpi_status status;
  	unsigned long long state;

  	if (!lid_device)
  		return -ENODEV;

  	status = acpi_evaluate_integer(lid_device->handle, "_LID", NULL,
  				       &state);
  	if (ACPI_FAILURE(status))
  		return -ENODEV;
  
  	return !!state;
  }
  EXPORT_SYMBOL(acpi_lid_open);

  static int acpi_lid_send_state(struct acpi_device *device)

  {

  	struct acpi_button *button = acpi_driver_data(device);

  	unsigned long long state;

  	acpi_status status;

  	int ret;

  	status = acpi_evaluate_integer(device->handle, "_LID", NULL, &state);

  	if (ACPI_FAILURE(status))
  		return -ENODEV;

  	/* input layer checks if event is redundant */
  	input_report_switch(button->input, SW_LID, !state);

  	input_sync(button->input);

  	if (state)
  		pm_wakeup_event(&device->dev, 0);

  	ret = blocking_notifier_call_chain(&acpi_lid_notifier, state, device);
  	if (ret == NOTIFY_DONE)
  		ret = blocking_notifier_call_chain(&acpi_lid_notifier, state,
  						   device);

  	if (ret == NOTIFY_DONE || ret == NOTIFY_OK) {
  		/*
  		 * It is also regarded as success if the notifier_chain
  		 * returns NOTIFY_OK or NOTIFY_DONE.
  		 */
  		ret = 0;
  	}

  	return ret;

  }

  static void acpi_button_notify(struct acpi_device *device, u32 event)

  {

  	struct acpi_button *button = acpi_driver_data(device);

  	struct input_dev *input;

  	switch (event) {

  	case ACPI_FIXED_HARDWARE_EVENT:
  		event = ACPI_BUTTON_NOTIFY_STATUS;
  		/* fall through */

  	case ACPI_BUTTON_NOTIFY_STATUS:

  		input = button->input;

  		if (button->type == ACPI_BUTTON_TYPE_LID) {

  			acpi_lid_send_state(device);

  		} else {
  			int keycode = test_bit(KEY_SLEEP, input->keybit) ?
  						KEY_SLEEP : KEY_POWER;
  
  			input_report_key(input, keycode, 1);
  			input_sync(input);
  			input_report_key(input, keycode, 0);

  			input_sync(input);

  
  			pm_wakeup_event(&device->dev, 0);

  		}

  		acpi_bus_generate_proc_event(device, event, ++button->pushed);

  		break;
  	default:
  		ACPI_DEBUG_PRINT((ACPI_DB_INFO,

  				  "Unsupported event [0x%x]
  ", event));

  		break;
  	}

  }

  static int acpi_button_resume(struct acpi_device *device)
  {

  	struct acpi_button *button = acpi_driver_data(device);

  	if (button->type == ACPI_BUTTON_TYPE_LID)

  		return acpi_lid_send_state(device);

  	return 0;
  }

  static int acpi_button_add(struct acpi_device *device)
  {

  	struct acpi_button *button;
  	struct input_dev *input;

  	const char *hid = acpi_device_hid(device);
  	char *name, *class;

  	int error;

  	button = kzalloc(sizeof(struct acpi_button), GFP_KERNEL);

  	if (!button)

  		return -ENOMEM;

  	device->driver_data = button;

  	button->input = input = input_allocate_device();
  	if (!input) {
  		error = -ENOMEM;
  		goto err_free_button;
  	}

  	name = acpi_device_name(device);
  	class = acpi_device_class(device);

  	if (!strcmp(hid, ACPI_BUTTON_HID_POWER) ||
  	    !strcmp(hid, ACPI_BUTTON_HID_POWERF)) {

  		button->type = ACPI_BUTTON_TYPE_POWER;

  		strcpy(name, ACPI_BUTTON_DEVICE_NAME_POWER);
  		sprintf(class, "%s/%s",

  			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_POWER);

  	} else if (!strcmp(hid, ACPI_BUTTON_HID_SLEEP) ||
  		   !strcmp(hid, ACPI_BUTTON_HID_SLEEPF)) {

  		button->type = ACPI_BUTTON_TYPE_SLEEP;

  		strcpy(name, ACPI_BUTTON_DEVICE_NAME_SLEEP);
  		sprintf(class, "%s/%s",

  			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_SLEEP);

  	} else if (!strcmp(hid, ACPI_BUTTON_HID_LID)) {

  		button->type = ACPI_BUTTON_TYPE_LID;

  		strcpy(name, ACPI_BUTTON_DEVICE_NAME_LID);
  		sprintf(class, "%s/%s",

  			ACPI_BUTTON_CLASS, ACPI_BUTTON_SUBCLASS_LID);

  	} else {

  		printk(KERN_ERR PREFIX "Unsupported hid [%s]
  ", hid);

  		error = -ENODEV;
  		goto err_free_input;

  	}

  	error = acpi_button_add_fs(device);
  	if (error)
  		goto err_free_input;

  	snprintf(button->phys, sizeof(button->phys), "%s/button/input0", hid);

  	input->name = name;

  	input->phys = button->phys;
  	input->id.bustype = BUS_HOST;
  	input->id.product = button->type;

  	input->dev.parent = &device->dev;

  	switch (button->type) {

  	case ACPI_BUTTON_TYPE_POWER:

  		input->evbit[0] = BIT_MASK(EV_KEY);

  		set_bit(KEY_POWER, input->keybit);

  		break;

  
  	case ACPI_BUTTON_TYPE_SLEEP:

  		input->evbit[0] = BIT_MASK(EV_KEY);

  		set_bit(KEY_SLEEP, input->keybit);

  		break;

  
  	case ACPI_BUTTON_TYPE_LID:

  		input->evbit[0] = BIT_MASK(EV_SW);

  		set_bit(SW_LID, input->swbit);

  		break;
  	}

  	error = input_register_device(input);
  	if (error)

  		goto err_remove_fs;

  	if (button->type == ACPI_BUTTON_TYPE_LID) {

  		acpi_lid_send_state(device);

  		/*
  		 * This assumes there's only one lid device, or if there are
  		 * more we only care about the last one...
  		 */
  		lid_device = device;
  	}

  
  	if (device->wakeup.flags.valid) {
  		/* Button's GPE is run-wake GPE */

  		acpi_enable_gpe(device->wakeup.gpe_device,

  				device->wakeup.gpe_number);

  		if (!device_may_wakeup(&device->dev)) {
  			device_set_wakeup_enable(&device->dev, true);
  			button->wakeup_enabled = true;
  		}

  	}

  	printk(KERN_INFO PREFIX "%s [%s]
  ", name, acpi_device_bid(device));

  	return 0;

   err_remove_fs:
  	acpi_button_remove_fs(device);
   err_free_input:
  	input_free_device(input);
   err_free_button:
  	kfree(button);
  	return error;

  }

  static int acpi_button_remove(struct acpi_device *device, int type)

  {

  	struct acpi_button *button = acpi_driver_data(device);

  	if (device->wakeup.flags.valid) {
  		acpi_disable_gpe(device->wakeup.gpe_device,

  				device->wakeup.gpe_number);

  		if (button->wakeup_enabled)
  			device_set_wakeup_enable(&device->dev, false);

  	}

  	acpi_button_remove_fs(device);

  	input_unregister_device(button->input);

  	kfree(button);

  	return 0;

  }

  static int __init acpi_button_init(void)

  {

  	return acpi_bus_register_driver(&acpi_button_driver);

  }

  static void __exit acpi_button_exit(void)

  {

  	acpi_bus_unregister_driver(&acpi_button_driver);

  }

  module_init(acpi_button_init);
  module_exit(acpi_button_exit);