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);