drivers/platform/x86/toshiba_bluetooth.c

   1 /*
   2  * Toshiba Bluetooth Enable Driver
   3  *
   4  * Copyright (C) 2009 Jes Sorensen <Jes.Sorensen@gmail.com>
   5  * Copyright (C) 2015 Azael Avalos <coproscefalo@gmail.com>
   6  *
   7  * Thanks to Matthew Garrett for background info on ACPI innards which
   8  * normal people aren't meant to understand :-)
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License version 2 as
  12  * published by the Free Software Foundation.
  13  *
  14  * Note the Toshiba Bluetooth RFKill switch seems to be a strange
  15  * fish. It only provides a BT event when the switch is flipped to
  16  * the 'on' position. When flipping it to 'off', the USB device is
  17  * simply pulled away underneath us, without any BT event being
  18  * delivered.
  19  */
  20
  21 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  22
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/init.h>
  26 #include <linux/types.h>
  27 #include <linux/acpi.h>
  28
  29 #define BT_KILLSWITCH_MASK      0x01
  30 #define BT_PLUGGED_MASK         0x40
  31 #define BT_POWER_MASK           0x80
  32
  33 MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
  34 MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
  35 MODULE_LICENSE("GPL");
  36
  37 static int toshiba_bt_rfkill_add(struct acpi_device *device);
  38 static int toshiba_bt_rfkill_remove(struct acpi_device *device);
  39 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);
  40
  41 static const struct acpi_device_id bt_device_ids[] = {
  42         { "TOS6205", 0},
  43         { "", 0},
  44 };
  45 MODULE_DEVICE_TABLE(acpi, bt_device_ids);
  46
  47 #ifdef CONFIG_PM_SLEEP
  48 static int toshiba_bt_resume(struct device *dev);
  49 #endif
  50 static SIMPLE_DEV_PM_OPS(toshiba_bt_pm, NULL, toshiba_bt_resume);
  51
  52 static struct acpi_driver toshiba_bt_rfkill_driver = {
  53         .name =         "Toshiba BT",
  54         .class =        "Toshiba",
  55         .ids =          bt_device_ids,
  56         .ops =          {
  57                                 .add =          toshiba_bt_rfkill_add,
  58                                 .remove =       toshiba_bt_rfkill_remove,
  59                                 .notify =       toshiba_bt_rfkill_notify,
  60                         },
  61         .owner =        THIS_MODULE,
  62         .drv.pm =       &toshiba_bt_pm,
  63 };
  64
  65 static int toshiba_bluetooth_present(acpi_handle handle)
  66 {
  67         acpi_status result;
  68         u64 bt_present;
  69
  70         /*
  71          * Some Toshiba laptops may have a fake TOS6205 device in
  72          * their ACPI BIOS, so query the _STA method to see if there
  73          * is really anything there.
  74          */
  75         result = acpi_evaluate_integer(handle, "_STA", NULL, &bt_present);
  76         if (ACPI_FAILURE(result)) {
  77                 pr_err("ACPI call to query Bluetooth presence failed");
  78                 return -ENXIO;
  79         } else if (!bt_present) {
  80                 pr_info("Bluetooth device not present\n");
  81                 return -ENODEV;
  82         }
  83
  84         return 0;
  85 }
  86
  87 static int toshiba_bluetooth_status(acpi_handle handle)
  88 {
  89         acpi_status result;
  90         u64 status;
  91
  92         result = acpi_evaluate_integer(handle, "BTST", NULL, &status);
  93         if (ACPI_FAILURE(result)) {
  94                 pr_err("Could not get Bluetooth device status\n");
  95                 return -ENXIO;
  96         }
  97
  98         pr_info("Bluetooth status %llu\n", status);
  99
 100         return status;
 101 }
 102
 103 static int toshiba_bluetooth_enable(acpi_handle handle)
 104 {
 105         acpi_status result;
 106         bool killswitch;
 107         bool powered;
 108         bool plugged;
 109         int status;
 110
 111         /*
 112          * Query ACPI to verify RFKill switch is set to 'on'.
 113          * If not, we return silently, no need to report it as
 114          * an error.
 115          */
 116         status = toshiba_bluetooth_status(handle);
 117         if (status < 0)
 118                 return status;
 119
 120         killswitch = (status & BT_KILLSWITCH_MASK) ? true : false;
 121         powered = (status & BT_POWER_MASK) ? true : false;
 122         plugged = (status & BT_PLUGGED_MASK) ? true : false;
 123
 124         if (!killswitch)
 125                 return 0;
 126         /*
 127          * This check ensures to only enable the device if it is powered
 128          * off or detached, as some recent devices somehow pass the killswitch
 129          * test, causing a loop enabling/disabling the device, see bug 93911.
 130          */
 131         if (powered || plugged)
 132                 return 0;
 133
 134         result = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
 135         if (ACPI_FAILURE(result)) {
 136                 pr_err("Could not attach USB Bluetooth device\n");
 137                 return -ENXIO;
 138         }
 139
 140         result = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
 141         if (ACPI_FAILURE(result)) {
 142                 pr_err("Could not power ON Bluetooth device\n");
 143                 return -ENXIO;
 144         }
 145
 146         return 0;
 147 }
 148
 149 static int toshiba_bluetooth_disable(acpi_handle handle)
 150 {
 151         acpi_status result;
 152
 153         result = acpi_evaluate_object(handle, "BTPF", NULL, NULL);
 154         if (ACPI_FAILURE(result)) {
 155                 pr_err("Could not power OFF Bluetooth device\n");
 156                 return -ENXIO;
 157         }
 158
 159         result = acpi_evaluate_object(handle, "DUSB", NULL, NULL);
 160         if (ACPI_FAILURE(result)) {
 161                 pr_err("Could not detach USB Bluetooth device\n");
 162                 return -ENXIO;
 163         }
 164
 165         return 0;
 166 }
 167
 168 static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
 169 {
 170         toshiba_bluetooth_enable(device->handle);
 171 }
 172
 173 #ifdef CONFIG_PM_SLEEP
 174 static int toshiba_bt_resume(struct device *dev)
 175 {
 176         return toshiba_bluetooth_enable(to_acpi_device(dev)->handle);
 177 }
 178 #endif
 179
 180 static int toshiba_bt_rfkill_add(struct acpi_device *device)
 181 {
 182         int result;
 183
 184         result = toshiba_bluetooth_present(device->handle);
 185         if (result)
 186                 return result;
 187
 188         pr_info("Toshiba ACPI Bluetooth device driver\n");
 189
 190         /* Enable the BT device */
 191         result = toshiba_bluetooth_enable(device->handle);
 192         if (result)
 193                 return result;
 194
 195         return result;
 196 }
 197
 198 static int toshiba_bt_rfkill_remove(struct acpi_device *device)
 199 {
 200         /* clean up */
 201         return toshiba_bluetooth_disable(device->handle);
 202 }
 203
 204 module_acpi_driver(toshiba_bt_rfkill_driver);