drivers/platform/x86/toshiba_bluetooth.c

   1 /*
   2  * Toshiba Bluetooth Enable Driver
   3  *
   4  * Copyright (C) 2009 Jes Sorensen <Jes.Sorensen@gmail.com>
   5  *
   6  * Thanks to Matthew Garrett for background info on ACPI innards which
   7  * normal people aren't meant to understand :-)
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License version 2 as
  11  * published by the Free Software Foundation.
  12  *
  13  * Note the Toshiba Bluetooth RFKill switch seems to be a strange
  14  * fish. It only provides a BT event when the switch is flipped to
  15  * the 'on' position. When flipping it to 'off', the USB device is
  16  * simply pulled away underneath us, without any BT event being
  17  * delivered.
  18  */
  19
  20 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  21
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/init.h>
  25 #include <linux/types.h>
  26 #include <acpi/acpi_bus.h>
  27 #include <acpi/acpi_drivers.h>
  28
  29 MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
  30 MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
  31 MODULE_LICENSE("GPL");
  32
  33
  34 static int toshiba_bt_rfkill_add(struct acpi_device *device);
  35 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type);
  36 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);
  37 static int toshiba_bt_resume(struct acpi_device *device);
  38
  39 static const struct acpi_device_id bt_device_ids[] = {
  40         { "TOS6205", 0},
  41         { "", 0},
  42 };
  43 MODULE_DEVICE_TABLE(acpi, bt_device_ids);
  44
  45 static struct acpi_driver toshiba_bt_rfkill_driver = {
  46         .name =         "Toshiba BT",
  47         .class =        "Toshiba",
  48         .ids =          bt_device_ids,
  49         .ops =          {
  50                                 .add =          toshiba_bt_rfkill_add,
  51                                 .remove =       toshiba_bt_rfkill_remove,
  52                                 .notify =       toshiba_bt_rfkill_notify,
  53                                 .resume =       toshiba_bt_resume,
  54                         },
  55         .owner =        THIS_MODULE,
  56 };
  57
  58
  59 static int toshiba_bluetooth_enable(acpi_handle handle)
  60 {
  61         acpi_status res1, res2;
  62         u64 result;
  63
  64         /*
  65          * Query ACPI to verify RFKill switch is set to 'on'.
  66          * If not, we return silently, no need to report it as
  67          * an error.
  68          */
  69         res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
  70         if (ACPI_FAILURE(res1))
  71                 return res1;
  72         if (!(result & 0x01))
  73                 return 0;
  74
  75         pr_info("Re-enabling Toshiba Bluetooth\n");
  76         res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
  77         res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
  78         if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
  79                 return 0;
  80
  81         pr_warn("Failed to re-enable Toshiba Bluetooth\n");
  82
  83         return -ENODEV;
  84 }
  85
  86 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
  87 {
  88         toshiba_bluetooth_enable(device->handle);
  89 }
  90
  91 static int toshiba_bt_resume(struct acpi_device *device)
  92 {
  93         return toshiba_bluetooth_enable(device->handle);
  94 }
  95
  96 static int toshiba_bt_rfkill_add(struct acpi_device *device)
  97 {
  98         acpi_status status;
  99         u64 bt_present;
 100         int result = -ENODEV;
 101
 102         /*
 103          * Some Toshiba laptops may have a fake TOS6205 device in
 104          * their ACPI BIOS, so query the _STA method to see if there
 105          * is really anything there, before trying to enable it.
 106          */
 107         status = acpi_evaluate_integer(device->handle, "_STA", NULL,
 108                                        &bt_present);
 109
 110         if (!ACPI_FAILURE(status) && bt_present) {
 111                 pr_info("Detected Toshiba ACPI Bluetooth device - "
 112                         "installing RFKill handler\n");
 113                 result = toshiba_bluetooth_enable(device->handle);
 114         }
 115
 116         return result;
 117 }
 118
 119 static int __init toshiba_bt_rfkill_init(void)
 120 {
 121         int result;
 122
 123         result = acpi_bus_register_driver(&toshiba_bt_rfkill_driver);
 124         if (result < 0) {
 125                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 126                                   "Error registering driver\n"));
 127                 return result;
 128         }
 129
 130         return 0;
 131 }
 132
 133 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type)
 134 {
 135         /* clean up */
 136         return 0;
 137 }
 138
 139 static void __exit toshiba_bt_rfkill_exit(void)
 140 {
 141         acpi_bus_unregister_driver(&toshiba_bt_rfkill_driver);
 142 }
 143
 144 module_init(toshiba_bt_rfkill_init);
 145 module_exit(toshiba_bt_rfkill_exit);