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