source: mainline/uspace/drv/vhc/addrmgm.c@ ad104e0

/*
 * Copyright (c) 2010 Vojtech Horky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup usb
 * @{
 */
/** @file
 * @brief Address management.
 */

#include <usb/usb.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <str_error.h>
#include <fibril_synch.h>

#include "vhcd.h"
#include "conn.h"

#define ADDRESS_COUNT 100
#define DEFAULT_ADDRESS 0

typedef struct {
        usb_address_t address;
        bool available;
} address_info_t;

static address_info_t dev_address[ADDRESS_COUNT];
fibril_mutex_t address_guard;

typedef struct {
        fibril_mutex_t condvar_guard;
        fibril_condvar_t condvar;
        bool available;
} reservable_address_info_t;

static reservable_address_info_t default_address;

void address_init(void)
{
        usb_address_t i;
        for (i = 0; i < ADDRESS_COUNT; i++) {
                dev_address[i].address = i + 1;
                dev_address[i].available = true;
        }

        fibril_mutex_initialize(&address_guard);
        fibril_mutex_initialize(&default_address.condvar_guard);
        fibril_condvar_initialize(&default_address.condvar);
}

int reserve_default_address(device_t *dev)
{
        fibril_mutex_lock(&default_address.condvar_guard);
        while (!default_address.available) {
                fibril_condvar_wait(&default_address.condvar,
                    &default_address.condvar_guard);
        }
        fibril_mutex_unlock(&default_address.condvar_guard);

        return EOK;
}

int release_default_address(device_t *dev)
{
        fibril_mutex_lock(&default_address.condvar_guard);
        default_address.available = true;
        fibril_condvar_signal(&default_address.condvar);
        fibril_mutex_unlock(&default_address.condvar_guard);

        return EOK;
}

int request_address(device_t *dev, usb_address_t *address)
{
        fibril_mutex_lock(&address_guard);
        usb_address_t i;
        bool found = false;
        for (i = 0; i < ADDRESS_COUNT; i++) {
                if (dev_address[i].available) {
                        dev_address[i].available = false;
                        *address = dev_address[i].address;
                        found = true;
                        break;
                }
        }
        fibril_mutex_unlock(&address_guard);

        if (!found) {
                return ELIMIT;
        } else {
                return EOK;
        }
}

int release_address(device_t *dev, usb_address_t address)
{
        if (address == DEFAULT_ADDRESS) {
                return EPERM;
        }

        int rc = EPERM;

        fibril_mutex_lock(&address_guard);
        usb_address_t i;
        for (i = 0; i < ADDRESS_COUNT; i++) {
                if (dev_address[i].address == address) {
                        if (dev_address[i].available) {
                                rc = ENOENT;
                                break;
                        }

                        dev_address[i].available = true;
                        rc = EOK;
                        break;
                }
        }
        fibril_mutex_unlock(&address_guard);

        return rc;
}

/**
 * @}
 */