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_LICENSE("GPL");
18 MODULE_AUTHOR("Alex Hung");
19 MODULE_ALIAS("acpi*:HPQ6001:*");
20 MODULE_ALIAS("acpi*:WSTADEF:*");
21 MODULE_ALIAS("acpi*:AMDI0051:*");
22 
23 static struct input_dev *wl_input_dev;
24 
25 static const struct acpi_device_id wl_ids[] = {
26 	{"HPQ6001", 0},
27 	{"WSTADEF", 0},
28 	{"AMDI0051", 0},
29 	{"", 0},
30 };
31 
32 static int wireless_input_setup(void)
33 {
34 	int err;
35 
36 	wl_input_dev = input_allocate_device();
37 	if (!wl_input_dev)
38 		return -ENOMEM;
39 
40 	wl_input_dev->name = "Wireless hotkeys";
41 	wl_input_dev->phys = "hpq6001/input0";
42 	wl_input_dev->id.bustype = BUS_HOST;
43 	wl_input_dev->evbit[0] = BIT(EV_KEY);
44 	set_bit(KEY_RFKILL, wl_input_dev->keybit);
45 
46 	err = input_register_device(wl_input_dev);
47 	if (err)
48 		goto err_free_dev;
49 
50 	return 0;
51 
52 err_free_dev:
53 	input_free_device(wl_input_dev);
54 	return err;
55 }
56 
57 static void wireless_input_destroy(void)
58 {
59 	input_unregister_device(wl_input_dev);
60 }
61 
62 static void wl_notify(struct acpi_device *acpi_dev, u32 event)
63 {
64 	if (event != 0x80) {
65 		pr_info("Received unknown event (0x%x)\n", event);
66 		return;
67 	}
68 
69 	input_report_key(wl_input_dev, KEY_RFKILL, 1);
70 	input_sync(wl_input_dev);
71 	input_report_key(wl_input_dev, KEY_RFKILL, 0);
72 	input_sync(wl_input_dev);
73 }
74 
75 static int wl_add(struct acpi_device *device)
76 {
77 	int err;
78 
79 	err = wireless_input_setup();
80 	if (err)
81 		pr_err("Failed to setup wireless hotkeys\n");
82 
83 	return err;
84 }
85 
86 static int wl_remove(struct acpi_device *device)
87 {
88 	wireless_input_destroy();
89 	return 0;
90 }
91 
92 static struct acpi_driver wl_driver = {
93 	.name	= "wireless-hotkey",
94 	.owner	= THIS_MODULE,
95 	.ids	= wl_ids,
96 	.ops	= {
97 		.add	= wl_add,
98 		.remove	= wl_remove,
99 		.notify	= wl_notify,
100 	},
101 };
102 
103 module_acpi_driver(wl_driver);
104