1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  Airplane mode button for AMD, HP & Xiaomi laptops
4 *
5 *  Copyright (C) 2014-2017 Alex Hung <alex.hung@canonical.com>
6 *  Copyright (C) 2021 Advanced Micro Devices
7 */
8
9#include <linux/kernel.h>
10#include <linux/module.h>
11#include <linux/init.h>
12#include <linux/input.h>
13#include <linux/platform_device.h>
14#include <linux/acpi.h>
15#include <acpi/acpi_bus.h>
16
17MODULE_LICENSE("GPL");
18MODULE_AUTHOR("Alex Hung");
19MODULE_ALIAS("acpi*:HPQ6001:*");
20MODULE_ALIAS("acpi*:WSTADEF:*");
21MODULE_ALIAS("acpi*:AMDI0051:*");
22
23struct wl_button {
24	struct input_dev *input_dev;
25	char phys[32];
26};
27
28static const struct acpi_device_id wl_ids[] = {
29	{"HPQ6001", 0},
30	{"WSTADEF", 0},
31	{"AMDI0051", 0},
32	{"", 0},
33};
34
35static int wireless_input_setup(struct acpi_device *device)
36{
37	struct wl_button *button = acpi_driver_data(device);
38	int err;
39
40	button->input_dev = input_allocate_device();
41	if (!button->input_dev)
42		return -ENOMEM;
43
44	snprintf(button->phys, sizeof(button->phys), "%s/input0", acpi_device_hid(device));
45
46	button->input_dev->name = "Wireless hotkeys";
47	button->input_dev->phys = button->phys;
48	button->input_dev->id.bustype = BUS_HOST;
49	button->input_dev->evbit[0] = BIT(EV_KEY);
50	set_bit(KEY_RFKILL, button->input_dev->keybit);
51
52	err = input_register_device(button->input_dev);
53	if (err)
54		goto err_free_dev;
55
56	return 0;
57
58err_free_dev:
59	input_free_device(button->input_dev);
60	return err;
61}
62
63static void wireless_input_destroy(struct acpi_device *device)
64{
65	struct wl_button *button = acpi_driver_data(device);
66
67	input_unregister_device(button->input_dev);
68	kfree(button);
69}
70
71static void wl_notify(struct acpi_device *acpi_dev, u32 event)
72{
73	struct wl_button *button = acpi_driver_data(acpi_dev);
74
75	if (event != 0x80) {
76		pr_info("Received unknown event (0x%x)\n", event);
77		return;
78	}
79
80	input_report_key(button->input_dev, KEY_RFKILL, 1);
81	input_sync(button->input_dev);
82	input_report_key(button->input_dev, KEY_RFKILL, 0);
83	input_sync(button->input_dev);
84}
85
86static int wl_add(struct acpi_device *device)
87{
88	struct wl_button *button;
89	int err;
90
91	button = kzalloc(sizeof(struct wl_button), GFP_KERNEL);
92	if (!button)
93		return -ENOMEM;
94
95	device->driver_data = button;
96
97	err = wireless_input_setup(device);
98	if (err) {
99		pr_err("Failed to setup wireless hotkeys\n");
100		kfree(button);
101	}
102
103	return err;
104}
105
106static void wl_remove(struct acpi_device *device)
107{
108	wireless_input_destroy(device);
109}
110
111static struct acpi_driver wl_driver = {
112	.name	= "wireless-hotkey",
113	.owner	= THIS_MODULE,
114	.ids	= wl_ids,
115	.ops	= {
116		.add	= wl_add,
117		.remove	= wl_remove,
118		.notify	= wl_notify,
119	},
120};
121
122module_acpi_driver(wl_driver);
123