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_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);