toshiba_bluetooth.c

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/*
 * Toshiba Bluetooth Enable Driver
 *
 * Copyright (C) 2009 Jes Sorensen <[email protected]>
 *
 * Thanks to Matthew Garrett for background info on ACPI innards which
 * normal people aren't meant to understand :-)
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Note the Toshiba Bluetooth RFKill switch seems to be a strange
 * fish. It only provides a BT event when the switch is flipped to
 * the 'on' position. When flipping it to 'off', the USB device is
 * simply pulled away underneath us, without any BT event being
 * delivered.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <acpi/acpi_bus.h>
#include <acpi/acpi_drivers.h>

MODULE_AUTHOR("Jes Sorensen <[email protected]>");
MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
MODULE_LICENSE("GPL");


static int toshiba_bt_rfkill_add(struct acpi_device *device);
static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type);
static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event);

static const struct acpi_device_id bt_device_ids[] = {
    { "TOS6205", 0},
    { "", 0},
};
MODULE_DEVICE_TABLE(acpi, bt_device_ids);

#ifdef CONFIG_PM_SLEEP
static int toshiba_bt_resume(struct device *dev);
#endif
static SIMPLE_DEV_PM_OPS(toshiba_bt_pm, NULL, toshiba_bt_resume);

static struct acpi_driver toshiba_bt_rfkill_driver = {
    .name =     "Toshiba BT",
    .class =    "Toshiba",
    .ids =      bt_device_ids,
    .ops =      {
                .add =      toshiba_bt_rfkill_add,
                .remove =   toshiba_bt_rfkill_remove,
                .notify =   toshiba_bt_rfkill_notify,
            },
    .owner =    THIS_MODULE,
    .drv.pm =   &toshiba_bt_pm,
};


static int toshiba_bluetooth_enable(acpi_handle handle)
{
    acpi_status res1, res2;
    u64 result;

    /*
     * Query ACPI to verify RFKill switch is set to 'on'.
     * If not, we return silently, no need to report it as
     * an error.
     */
    res1 = acpi_evaluate_integer(handle, "BTST", NULL, &result);
    if (ACPI_FAILURE(res1))
        return res1;
    if (!(result & 0x01))
        return 0;

    pr_info("Re-enabling Toshiba Bluetooth\n");
    res1 = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
    res2 = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
    if (!ACPI_FAILURE(res1) || !ACPI_FAILURE(res2))
        return 0;

    pr_warn("Failed to re-enable Toshiba Bluetooth\n");

    return -ENODEV;
}

static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
{
    toshiba_bluetooth_enable(device->handle);
}

#ifdef CONFIG_PM_SLEEP
static int toshiba_bt_resume(struct device *dev)
{
    return toshiba_bluetooth_enable(to_acpi_device(dev)->handle);
}
#endif

static int toshiba_bt_rfkill_add(struct acpi_device *device)
{
    acpi_status status;
    u64 bt_present;
    int result = -ENODEV;

    /*
     * Some Toshiba laptops may have a fake TOS6205 device in
     * their ACPI BIOS, so query the _STA method to see if there
     * is really anything there, before trying to enable it.
     */
    status = acpi_evaluate_integer(device->handle, "_STA", NULL,
                       &bt_present);

    if (!ACPI_FAILURE(status) && bt_present) {
        pr_info("Detected Toshiba ACPI Bluetooth device - "
            "installing RFKill handler\n");
        result = toshiba_bluetooth_enable(device->handle);
    }

    return result;
}

static int toshiba_bt_rfkill_remove(struct acpi_device *device, int type)
{
    /* clean up */
    return 0;
}

module_acpi_driver(toshiba_bt_rfkill_driver);