drivers/platform/x86/wireless-hotkey.c

   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 <[email protected]>
   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 struct wl_button {
  24         struct input_dev *input_dev;
  25         char phys[32];
  26 };
  27
  28 static const struct acpi_device_id wl_ids[] = {
  29         {"HPQ6001", 0},
  30         {"WSTADEF", 0},
  31         {"AMDI0051", 0},
  32         {"", 0},
  33 };
  34
  35 static 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
  58 err_free_dev:
  59         input_free_device(button->input_dev);
  60         return err;
  61 }
  62
  63 static 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
  71 static 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
  86 static 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
 106 static void wl_remove(struct acpi_device *device)
 107 {
 108         wireless_input_destroy(device);
 109 }
 110
 111 static 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
 122 module_acpi_driver(wl_driver);