toshiba_bluetooth.c

/*
 * Toshiba Bluetooth Enable Driver
 *
 * Copyright (C) 2009 Jes Sorensen <Jes.Sorensen@gmail.com>
 * Copyright (C) 2015 Azael Avalos <coproscefalo@gmail.com>
 *
 * 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 <linux/acpi.h>

#define BT_KILLSWITCH_MASK  0x01
#define BT_PLUGGED_MASK     0x40
#define BT_POWER_MASK       0x80

MODULE_AUTHOR("Jes Sorensen <Jes.Sorensen@gmail.com>");
MODULE_DESCRIPTION("Toshiba Laptop ACPI Bluetooth Enable Driver");
MODULE_LICENSE("GPL");

static int toshiba_bluetooth_add(struct acpi_device *device);
static int toshiba_bluetooth_remove(struct acpi_device *device);
static void toshiba_bluetooth_notify(struct acpi_device *device, u32 event);

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

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

static struct acpi_driver toshiba_bluetooth_driver = {
    .name =     "Toshiba BT",
    .class =    "Toshiba",
    .ids =      toshiba_bluetooth_device_ids,
    .ops =      {
                .add =      toshiba_bluetooth_add,
                .remove =   toshiba_bluetooth_remove,
                .notify =   toshiba_bluetooth_notify,
            },
    .owner =    THIS_MODULE,
    .drv.pm =   &toshiba_bluetooth_pm,
};

static int toshiba_bluetooth_present(acpi_handle handle)
{
    acpi_status result;
    u64 bt_present;

    /*
     * 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.
     */
    result = acpi_evaluate_integer(handle, "_STA", NULL, &bt_present);
    if (ACPI_FAILURE(result)) {
        pr_err("ACPI call to query Bluetooth presence failed");
        return -ENXIO;
    } else if (!bt_present) {
        pr_info("Bluetooth device not present\n");
        return -ENODEV;
    }

    return 0;
}

static int toshiba_bluetooth_status(acpi_handle handle)
{
    acpi_status result;
    u64 status;

    result = acpi_evaluate_integer(handle, "BTST", NULL, &status);
    if (ACPI_FAILURE(result)) {
        pr_err("Could not get Bluetooth device status\n");
        return -ENXIO;
    }

    pr_info("Bluetooth status %llu\n", status);

    return status;
}

static int toshiba_bluetooth_enable(acpi_handle handle)
{
    acpi_status result;

    result = acpi_evaluate_object(handle, "AUSB", NULL, NULL);
    if (ACPI_FAILURE(result)) {
        pr_err("Could not attach USB Bluetooth device\n");
        return -ENXIO;
    }

    result = acpi_evaluate_object(handle, "BTPO", NULL, NULL);
    if (ACPI_FAILURE(result)) {
        pr_err("Could not power ON Bluetooth device\n");
        return -ENXIO;
    }

    return 0;
}

static int toshiba_bluetooth_disable(acpi_handle handle)
{
    acpi_status result;

    result = acpi_evaluate_object(handle, "BTPF", NULL, NULL);
    if (ACPI_FAILURE(result)) {
        pr_err("Could not power OFF Bluetooth device\n");
        return -ENXIO;
    }

    result = acpi_evaluate_object(handle, "DUSB", NULL, NULL);
    if (ACPI_FAILURE(result)) {
        pr_err("Could not detach USB Bluetooth device\n");
        return -ENXIO;
    }

    return 0;
}

static void toshiba_bluetooth_notify(struct acpi_device *device, u32 event)
{
    int status;

    pr_info("Received event %x\n", event);

    /* Query the status of the Bluetooth device */
    status = toshiba_bluetooth_status(device->handle);
    if (status < 0)
        pr_err("Error while querying Bluetooth status\n");

    pr_info("Switch status %x\n", status & BT_KILLSWITCH_MASK);
    pr_info("Power status %x\n", status & BT_POWER_MASK);
    pr_info("Plug status %x\n", status & BT_PLUGGED_MASK);

    /* TODO: Add event handling here depending on Bluetooth status */
}

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

static int toshiba_bluetooth_add(struct acpi_device *device)
{
    int result;

    result = toshiba_bluetooth_present(device->handle);
    if (result)
        return result;

    pr_info("Toshiba ACPI Bluetooth device driver\n");

    /* Enable the BT device */
    result = toshiba_bluetooth_enable(device->handle);
    if (result)
        return result;

    /* Query the status of the BT device */
    result = toshiba_bluetooth_status(device->handle);
    if (result < 0)
        return result;

    pr_info("Switch status %x\n", result & BT_KILLSWITCH_MASK);
    pr_info("Power status %x\n", result & BT_POWER_MASK);
    pr_info("Plug status %x\n", result & BT_PLUGGED_MASK);

    return 0;
}

static int toshiba_bluetooth_remove(struct acpi_device *device)
{
    /* Clean up */
    return toshiba_bluetooth_disable(device->handle);
}

module_acpi_driver(toshiba_bluetooth_driver);