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 #include <linux/kernel.h>
  21 #include <linux/module.h>
  22 #include <linux/init.h>
  23 #include <linux/types.h>
  24 #include <acpi/acpi_bus.h>
  25 #include <acpi/acpi_drivers.h>
  26
  27 MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
  28 MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
  29 MODULE_LICENSE("GPL");
  30
  31
  32 static int toshiba_bt_rfkill_add(struct acpi_device *device);
  33 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type);
  34 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);
  35 static int toshiba_bt_resume(struct acpi_device *device);
  36
  37 static const struct acpi_device_id bt_device_ids[] = {
  38         { "TOS6205", 0},
  39         { "", 0},
  40 };
  41 MODULE_DEVICE_TABLE(acpi, bt_device_ids);
  42
  43 static struct acpi_driver toshiba_bt_rfkill_driver = {
  44         .name =         "Toshiba BT",
  45         .class =        "Toshiba",
  46         .ids =          bt_device_ids,
  47         .ops =          {
  48                                 .add =          toshiba_bt_rfkill_add,
  49                                 .remove =       toshiba_bt_rfkill_remove,
  50                                 .notify =       toshiba_bt_rfkill_notify,
  51                                 .resume =       toshiba_bt_resume,
  52                         },
  53         .owner =        THIS_MODULE,
  54 };
  55
  56
  57 static int toshiba_bluetooth_enable(acpi_handle handle)
  58 {
  59         acpi_status res1, res2;
  60         u64 result;
  61
  62         /*
  63          * Query ACPI to verify RFKill switch is set to 'on'.
  64          * If not, we return silently, no need to report it as
  65          * an error.
  66          */
  67         res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
  68         if (ACPI_FAILURE(res1))
  69                 return res1;
  70         if (!(result & 0x01))
  71                 return 0;
  72
  73         printk(KERN_INFO "toshiba_bluetooth: Re-enabling Toshiba Bluetooth\n");
  74         res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
  75         res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
  76         if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
  77                 return 0;
  78
  79         printk(KERN_WARNING "toshiba_bluetooth: Failed to re-enable "
  80                "Toshiba Bluetooth\n");
  81
  82         return -ENODEV;
  83 }
  84
  85 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
  86 {
  87         toshiba_bluetooth_enable(device->handle);
  88 }
  89
  90 static int toshiba_bt_resume(struct acpi_device *device)
  91 {
  92         return toshiba_bluetooth_enable(device->handle);
  93 }
  94
  95 static int toshiba_bt_rfkill_add(struct acpi_device *device)
  96 {
  97         acpi_status status;
  98         u64 bt_present;
  99         int result = -ENODEV;
 100
 101         /*
 102          * Some Toshiba laptops may have a fake TOS6205 device in
 103          * their ACPI BIOS, so query the _STA method to see if there
 104          * is really anything there, before trying to enable it.
 105          */
 106         status = acpi_evaluate_integer(device->handle, "_STA", NULL,
 107                                        &bt_present);
 108
 109         if (!ACPI_FAILURE(status) && bt_present) {
 110                 printk(KERN_INFO "Detected Toshiba ACPI Bluetooth device - "
 111                       "installing RFKill handler\n");
 112                 result = toshiba_bluetooth_enable(device->handle);
 113         }
 114
 115         return result;
 116 }
 117
 118 static int __init toshiba_bt_rfkill_init(void)
 119 {
 120         int result;
 121
 122         result = acpi_bus_register_driver(&toshiba_bt_rfkill_driver);
 123         if (result < 0) {
 124                 ACPI_DEBUG_PRINT((ACPI_DB_ERROR,
 125                                   "Error registering driver\n"));
 126                 return result;
 127         }
 128
 129         return 0;
 130 }
 131
 132 static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type)
 133 {
 134         /* clean up */
 135         return 0;
 136 }
 137
 138 static void __exit toshiba_bt_rfkill_exit(void)
 139 {
 140         acpi_bus_unregister_driver(&toshiba_bt_rfkill_driver);
 141 }
 142
 143 module_init(toshiba_bt_rfkill_init);
 144 module_exit(toshiba_bt_rfkill_exit);