// SPDX-License-Identifier: GPL-2.0-only
/*
 * 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 :-)
 */

#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>
#include <linux/rfkill.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");

struct toshiba_bluetooth_dev {
        struct acpi_device *acpi_dev;
        struct rfkill *rfk;

        bool killswitch;
        bool plugged;
        bool powered;
};

static int toshiba_bt_rfkill_add(struct acpi_device *device);
static void toshiba_bt_rfkill_remove(struct acpi_device *device);
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,
                        },
        .drv.pm =       &toshiba_bt_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\n");
                return -ENXIO;
        }

        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;
        }

        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;
}

/* Helper function */
static int toshiba_bluetooth_sync_status(struct toshiba_bluetooth_dev *bt_dev)
{
        int status;

        status = toshiba_bluetooth_status(bt_dev->acpi_dev->handle);
        if (status < 0) {
                pr_err("Could not sync bluetooth device status\n");
                return status;
        }

        bt_dev->killswitch = (status & BT_KILLSWITCH_MASK) ? true : false;
        bt_dev->plugged = (status & BT_PLUGGED_MASK) ? true : false;
        bt_dev->powered = (status & BT_POWER_MASK) ? true : false;

        pr_debug("Bluetooth status %d killswitch %d plugged %d powered %d\n",
                 status, bt_dev->killswitch, bt_dev->plugged, bt_dev->powered);

        return 0;
}

/* RFKill handlers */
static int bt_rfkill_set_block(void *data, bool blocked)
{
        struct toshiba_bluetooth_dev *bt_dev = data;
        int ret;

        ret = toshiba_bluetooth_sync_status(bt_dev);
        if (ret)
                return ret;

        if (!bt_dev->killswitch)
                return 0;

        if (blocked)
                ret = toshiba_bluetooth_disable(bt_dev->acpi_dev->handle);
        else
                ret = toshiba_bluetooth_enable(bt_dev->acpi_dev->handle);

        return ret;
}

static void bt_rfkill_poll(struct rfkill *rfkill, void *data)
{
        struct toshiba_bluetooth_dev *bt_dev = data;

        if (toshiba_bluetooth_sync_status(bt_dev))
                return;

        /*
         * 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.
         */
        rfkill_set_hw_state(bt_dev->rfk, !bt_dev->killswitch);
}

static const struct rfkill_ops rfk_ops = {
        .set_block = bt_rfkill_set_block,
        .poll = bt_rfkill_poll,
};

/* ACPI driver functions */
static void toshiba_bt_rfkill_notify(struct acpi_device *device, u32 event)
{
        struct toshiba_bluetooth_dev *bt_dev = acpi_driver_data(device);

        if (toshiba_bluetooth_sync_status(bt_dev))
                return;

        rfkill_set_hw_state(bt_dev->rfk, !bt_dev->killswitch);
}

#ifdef CONFIG_PM_SLEEP
static int toshiba_bt_resume(struct device *dev)
{
        struct toshiba_bluetooth_dev *bt_dev;
        int ret;

        bt_dev = acpi_driver_data(to_acpi_device(dev));

        ret = toshiba_bluetooth_sync_status(bt_dev);
        if (ret)
                return ret;

        rfkill_set_hw_state(bt_dev->rfk, !bt_dev->killswitch);

        return 0;
}
#endif

static int toshiba_bt_rfkill_add(struct acpi_device *device)
{
        struct toshiba_bluetooth_dev *bt_dev;
        int result;

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

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

        bt_dev = kzalloc_obj(*bt_dev);
        if (!bt_dev)
                return -ENOMEM;
        bt_dev->acpi_dev = device;
        device->driver_data = bt_dev;
        dev_set_drvdata(&device->dev, bt_dev);

        result = toshiba_bluetooth_sync_status(bt_dev);
        if (result) {
                kfree(bt_dev);
                return result;
        }

        bt_dev->rfk = rfkill_alloc("Toshiba Bluetooth",
                                   &device->dev,
                                   RFKILL_TYPE_BLUETOOTH,
                                   &rfk_ops,
                                   bt_dev);
        if (!bt_dev->rfk) {
                pr_err("Unable to allocate rfkill device\n");
                kfree(bt_dev);
                return -ENOMEM;
        }

        rfkill_set_hw_state(bt_dev->rfk, !bt_dev->killswitch);

        result = rfkill_register(bt_dev->rfk);
        if (result) {
                pr_err("Unable to register rfkill device\n");
                rfkill_destroy(bt_dev->rfk);
                kfree(bt_dev);
        }

        return result;
}

static void toshiba_bt_rfkill_remove(struct acpi_device *device)
{
        struct toshiba_bluetooth_dev *bt_dev = acpi_driver_data(device);

        /* clean up */
        if (bt_dev->rfk) {
                rfkill_unregister(bt_dev->rfk);
                rfkill_destroy(bt_dev->rfk);
        }

        kfree(bt_dev);

        toshiba_bluetooth_disable(device->handle);
}

module_acpi_driver(toshiba_bt_rfkill_driver);