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	if (err)
89		pr_err("Failed to setup hp wireless hotkeys\n");
90
91	return err;
92}
93
94static int hpwl_remove(struct acpi_device *device)
95{
96	hp_wireless_input_destroy();
97	return 0;
98}
99
100static struct acpi_driver hpwl_driver = {
101	.name	= "hp-wireless",
102	.owner	= THIS_MODULE,
103	.ids	= hpwl_ids,
104	.ops	= {
105		.add	= hpwl_add,
106		.remove	= hpwl_remove,
107		.notify	= hpwl_notify,
108	},
109};
110
111static int __init hpwl_init(void)
112{
113	int err;
114
115	pr_info("Initializing HPQ6001 module\n");
116	err = acpi_bus_register_driver(&hpwl_driver);
117	if (err) {
118		pr_err("Unable to register HP wireless control driver.\n");
119		goto error_acpi_register;
120	}
121
122	return 0;
123
124error_acpi_register:
125	return err;
126}
127
128static void __exit hpwl_exit(void)
129{
130	pr_info("Exiting HPQ6001 module\n");
131	acpi_bus_unregister_driver(&hpwl_driver);
132}
133
134module_init(hpwl_init);
135module_exit(hpwl_exit);
136