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(d: device);
38 int err;
39
40 button->input_dev = input_allocate_device();
41 if (!button->input_dev)
42 return -ENOMEM;
43
44 snprintf(buf: button->phys, size: sizeof(button->phys), fmt: "%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, addr: 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(dev: 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(d: device);
66
67 input_unregister_device(button->input_dev);
68 kfree(objp: button);
69}
70
71static void wl_notify(struct acpi_device *acpi_dev, u32 event)
72{
73 struct wl_button *button = acpi_driver_data(d: 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(dev: button->input_dev, KEY_RFKILL, value: 1);
81 input_sync(dev: button->input_dev);
82 input_report_key(dev: button->input_dev, KEY_RFKILL, value: 0);
83 input_sync(dev: 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(size: 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(objp: 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

source code of linux/drivers/platform/x86/wireless-hotkey.c