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_DESCRIPTION("Airplane mode button for AMD, HP & Xiaomi laptops");
 18MODULE_LICENSE("GPL");
 19MODULE_AUTHOR("Alex Hung");
 20MODULE_ALIAS("acpi*:HPQ6001:*");
 21MODULE_ALIAS("acpi*:WSTADEF:*");
 22MODULE_ALIAS("acpi*:AMDI0051:*");
 23MODULE_ALIAS("acpi*:LGEX0815:*");
 24
 25struct wl_button {
 26	struct input_dev *input_dev;
 27	char phys[32];
 28};
 29
 30static const struct acpi_device_id wl_ids[] = {
 31	{"HPQ6001", 0},
 32	{"WSTADEF", 0},
 33	{"AMDI0051", 0},
 34	{"LGEX0815", 0},
 35	{"", 0},
 36};
 37
 38static 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
 61err_free_dev:
 62	input_free_device(button->input_dev);
 63	return err;
 64}
 65
 66static 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
 74static 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
 89static 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
109static void wl_remove(struct acpi_device *device)
110{
111	wireless_input_destroy(device);
112}
113
114static 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
124module_acpi_driver(wl_driver);