xref: /linux/drivers/platform/x86/wireless-hotkey.c (revision c532de5a67a70f8533d495f8f2aaa9a0491c3ad0)
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 
17 MODULE_DESCRIPTION("Airplane mode button for AMD, HP & Xiaomi laptops");
18 MODULE_LICENSE("GPL");
19 MODULE_AUTHOR("Alex Hung");
20 MODULE_ALIAS("acpi*:HPQ6001:*");
21 MODULE_ALIAS("acpi*:WSTADEF:*");
22 MODULE_ALIAS("acpi*:AMDI0051:*");
23 MODULE_ALIAS("acpi*:LGEX0815:*");
24 
25 struct wl_button {
26 	struct input_dev *input_dev;
27 	char phys[32];
28 };
29 
30 static const struct acpi_device_id wl_ids[] = {
31 	{"HPQ6001", 0},
32 	{"WSTADEF", 0},
33 	{"AMDI0051", 0},
34 	{"LGEX0815", 0},
35 	{"", 0},
36 };
37 
38 static int wireless_input_setup(struct acpi_device *device)
39 {
40 	struct wl_button *button = acpi_driver_data(device);
41 	int err;
42 
43 	button->input_dev = input_allocate_device();
44 	if (!button->input_dev)
45 		return -ENOMEM;
46 
47 	snprintf(button->phys, sizeof(button->phys), "%s/input0", acpi_device_hid(device));
48 
49 	button->input_dev->name = "Wireless hotkeys";
50 	button->input_dev->phys = button->phys;
51 	button->input_dev->id.bustype = BUS_HOST;
52 	button->input_dev->evbit[0] = BIT(EV_KEY);
53 	set_bit(KEY_RFKILL, button->input_dev->keybit);
54 
55 	err = input_register_device(button->input_dev);
56 	if (err)
57 		goto err_free_dev;
58 
59 	return 0;
60 
61 err_free_dev:
62 	input_free_device(button->input_dev);
63 	return err;
64 }
65 
66 static void wireless_input_destroy(struct acpi_device *device)
67 {
68 	struct wl_button *button = acpi_driver_data(device);
69 
70 	input_unregister_device(button->input_dev);
71 	kfree(button);
72 }
73 
74 static void wl_notify(struct acpi_device *acpi_dev, u32 event)
75 {
76 	struct wl_button *button = acpi_driver_data(acpi_dev);
77 
78 	if (event != 0x80) {
79 		pr_info("Received unknown event (0x%x)\n", event);
80 		return;
81 	}
82 
83 	input_report_key(button->input_dev, KEY_RFKILL, 1);
84 	input_sync(button->input_dev);
85 	input_report_key(button->input_dev, KEY_RFKILL, 0);
86 	input_sync(button->input_dev);
87 }
88 
89 static int wl_add(struct acpi_device *device)
90 {
91 	struct wl_button *button;
92 	int err;
93 
94 	button = kzalloc(sizeof(struct wl_button), GFP_KERNEL);
95 	if (!button)
96 		return -ENOMEM;
97 
98 	device->driver_data = button;
99 
100 	err = wireless_input_setup(device);
101 	if (err) {
102 		pr_err("Failed to setup wireless hotkeys\n");
103 		kfree(button);
104 	}
105 
106 	return err;
107 }
108 
109 static void wl_remove(struct acpi_device *device)
110 {
111 	wireless_input_destroy(device);
112 }
113 
114 static struct acpi_driver wl_driver = {
115 	.name	= "wireless-hotkey",
116 	.ids	= wl_ids,
117 	.ops	= {
118 		.add	= wl_add,
119 		.remove	= wl_remove,
120 		.notify	= wl_notify,
121 	},
122 };
123 
124 module_acpi_driver(wl_driver);
125