1/*
  2 *  hp-wireless button for Windows 8
  3 *
  4 *  Copyright (C) 2014 Alex Hung <alex.hung@canonical.com>
  5 *
  6 *  This program is free software; you can redistribute it and/or modify
  7 *  it under the terms of the GNU General Public License as published by
  8 *  the Free Software Foundation; either version 2 of the License, or
  9 *  (at your option) any later version.
 10 *
 11 *  This program is distributed in the hope that it will be useful,
 12 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 13 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 14 *  GNU General Public License for more details.
 15 *
 16 *  You should have received a copy of the GNU General Public License along
 17 *  with this program; if not, write to the Free Software Foundation, Inc.,
 18 *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 19 */
 20
 21#include <linux/kernel.h>
 22#include <linux/module.h>
 23#include <linux/init.h>
 24#include <linux/input.h>
 25#include <linux/platform_device.h>
 26#include <linux/acpi.h>
 27#include <acpi/acpi_bus.h>
 28
 29MODULE_LICENSE("GPL");
 30MODULE_AUTHOR("Alex Hung");
 31MODULE_ALIAS("acpi*:HPQ6001:*");
 32
 33static struct input_dev *hpwl_input_dev;
 34
 35static const struct acpi_device_id hpwl_ids[] = {
 36	{"HPQ6001", 0},
 37	{"", 0},
 38};
 39
 40static int hp_wireless_input_setup(void)
 41{
 42	int err;
 43
 44	hpwl_input_dev = input_allocate_device();
 45	if (!hpwl_input_dev)
 46		return -ENOMEM;
 47
 48	hpwl_input_dev->name = "HP Wireless hotkeys";
 49	hpwl_input_dev->phys = "hpq6001/input0";
 50	hpwl_input_dev->id.bustype = BUS_HOST;
 51	hpwl_input_dev->evbit[0] = BIT(EV_KEY);
 52	set_bit(KEY_RFKILL, hpwl_input_dev->keybit);
 53
 54	err = input_register_device(hpwl_input_dev);
 55	if (err)
 56		goto err_free_dev;
 57
 58	return 0;
 59
 60err_free_dev:
 61	input_free_device(hpwl_input_dev);
 62	return err;
 63}
 64
 65static void hp_wireless_input_destroy(void)
 66{
 67	input_unregister_device(hpwl_input_dev);
 68}
 69
 70static void hpwl_notify(struct acpi_device *acpi_dev, u32 event)
 71{
 72	if (event != 0x80) {
 73		pr_info("Received unknown event (0x%x)\n", event);
 74		return;
 75	}
 76
 77	input_report_key(hpwl_input_dev, KEY_RFKILL, 1);
 78	input_sync(hpwl_input_dev);
 79	input_report_key(hpwl_input_dev, KEY_RFKILL, 0);
 80	input_sync(hpwl_input_dev);
 81}
 82
 83static int hpwl_add(struct acpi_device *device)
 84{
 85	int err;
 86
 87	err = hp_wireless_input_setup();
 88	return err;
 89}
 90
 91static int hpwl_remove(struct acpi_device *device)
 92{
 93	hp_wireless_input_destroy();
 94	return 0;
 95}
 96
 97static struct acpi_driver hpwl_driver = {
 98	.name	= "hp-wireless",
 99	.owner	= THIS_MODULE,
100	.ids	= hpwl_ids,
101	.ops	= {
102		.add	= hpwl_add,
103		.remove	= hpwl_remove,
104		.notify	= hpwl_notify,
105	},
106};
107
108static int __init hpwl_init(void)
109{
110	int err;
111
112	pr_info("Initializing HPQ6001 module\n");
113	err = acpi_bus_register_driver(&hpwl_driver);
114	if (err) {
115		pr_err("Unable to register HP wireless control driver.\n");
116		goto error_acpi_register;
117	}
118
119	return 0;
120
121error_acpi_register:
122	return err;
123}
124
125static void __exit hpwl_exit(void)
126{
127	pr_info("Exiting HPQ6001 module\n");
128	acpi_bus_unregister_driver(&hpwl_driver);
129}
130
131module_init(hpwl_init);
132module_exit(hpwl_exit);