kernel/drivers/platform/x86/hp-wireless.c

   1 /*
   2  *  hp-wireless button for Windows 8
   3  *
   4  *  Copyright (C) 2014 Alex Hung <alex.hung@canonical.com>
   5  *
   6  *  This program is free software; you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation; either version 2 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  This program is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License along
  17  *  with this program; if not, write to the Free Software Foundation, Inc.,
  18  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <linux/kernel.h>
  22 #include <linux/module.h>
  23 #include <linux/init.h>
  24 #include <linux/input.h>
  25 #include <linux/platform_device.h>
  26 #include <linux/acpi.h>
  27 #include <acpi/acpi_bus.h>
  28
  29 MODULE_LICENSE("GPL");
  30 MODULE_AUTHOR("Alex Hung");
  31 MODULE_ALIAS("acpi*:HPQ6001:*");
  32
  33 static struct input_dev *hpwl_input_dev;
  34
  35 static const struct acpi_device_id hpwl_ids[] = {
  36         {"HPQ6001", 0},
  37         {"", 0},
  38 };
  39
  40 static int hp_wireless_input_setup(void)
  41 {
  42         int err;
  43
  44         hpwl_input_dev = input_allocate_device();
  45         if (!hpwl_input_dev)
  46                 return -ENOMEM;
  47
  48         hpwl_input_dev->name = "HP Wireless hotkeys";
  49         hpwl_input_dev->phys = "hpq6001/input0";
  50         hpwl_input_dev->id.bustype = BUS_HOST;
  51         hpwl_input_dev->evbit[0] = BIT(EV_KEY);
  52         set_bit(KEY_RFKILL, hpwl_input_dev->keybit);
  53
  54         err = input_register_device(hpwl_input_dev);
  55         if (err)
  56                 goto err_free_dev;
  57
  58         return 0;
  59
  60 err_free_dev:
  61         input_free_device(hpwl_input_dev);
  62         return err;
  63 }
  64
  65 static void hp_wireless_input_destroy(void)
  66 {
  67         input_unregister_device(hpwl_input_dev);
  68 }
  69
  70 static void hpwl_notify(struct acpi_device *acpi_dev, u32 event)
  71 {
  72         if (event != 0x80) {
  73                 pr_info("Received unknown event (0x%x)\n", event);
  74                 return;
  75         }
  76
  77         input_report_key(hpwl_input_dev, KEY_RFKILL, 1);
  78         input_sync(hpwl_input_dev);
  79         input_report_key(hpwl_input_dev, KEY_RFKILL, 0);
  80         input_sync(hpwl_input_dev);
  81 }
  82
  83 static int hpwl_add(struct acpi_device *device)
  84 {
  85         int err;
  86
  87         err = hp_wireless_input_setup();
  88         if (err)
  89                 pr_err("Failed to setup hp wireless hotkeys\n");
  90
  91         return err;
  92 }
  93
  94 static int hpwl_remove(struct acpi_device *device)
  95 {
  96         hp_wireless_input_destroy();
  97         return 0;
  98 }
  99
 100 static struct acpi_driver hpwl_driver = {
 101         .name   = "hp-wireless",
 102         .owner  = THIS_MODULE,
 103         .ids    = hpwl_ids,
 104         .ops    = {
 105                 .add    = hpwl_add,
 106                 .remove = hpwl_remove,
 107                 .notify = hpwl_notify,
 108         },
 109 };
 110
 111 static int __init hpwl_init(void)
 112 {
 113         int err;
 114
 115         pr_info("Initializing HPQ6001 module\n");
 116         err = acpi_bus_register_driver(&hpwl_driver);
 117         if (err) {
 118                 pr_err("Unable to register HP wireless control driver.\n");
 119                 goto error_acpi_register;
 120         }
 121
 122         return 0;
 123
 124 error_acpi_register:
 125         return err;
 126 }
 127
 128 static void __exit hpwl_exit(void)
 129 {
 130         pr_info("Exiting HPQ6001 module\n");
 131         acpi_bus_unregister_driver(&hpwl_driver);
 132 }
 133
 134 module_init(hpwl_init);
 135 module_exit(hpwl_exit);