Colony

/**

 * Copyright (c) 2009 Colony Project

 *

 * Permission is hereby granted, free of charge, to any person

 * obtaining a copy of this software and associated documentation

 * files (the "Software"), to deal in the Software without

 * restriction, including without limitation the rights to use,

 * copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the

 * Software is furnished to do so, subject to the following

 * conditions:

 *

 * The above copyright notice and this permission notice shall be

 * included in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,

 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES

 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND

 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,

 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING

 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR

 * OTHER DEALINGS IN THE SOFTWARE.

 **/

/**

 * @file wireless.c

 * @brief Wireless library

 *

 * Implementation of high level wireless communication.

 *

 * @author Colony Project, CMU Robotics Club

 **/

#include <string.h>

#include "wl_defs.h"

#include "wireless.h"

#include "xbee.h"

// this is the common wireless file

/**

 * @addtogroup wireless Wireless

 * @{

 **/

/* holds pointers to all normal-priority packet handlers

   group handler located at index of group number

   group numbers with handlers undefined are NULL

 */

void (*handlers[WL_NUM_PACKET_GROUPS])(void);

/**

 * initialization function:

 * set up xbee communication and packet handler infrastructure

 *

 * @return 0 on success, or error code

 **/

int8_t wl_init(void) {

    // check for duplicate initialization

    if(init_flag == INIT_YES) {

        return WL_ERROR_INIT_ALREADY_INITD;

    }

    // set flag for checking duplicate initializations

    init_flag = INIT_YES;

    // reset packet handler array

    memset(wl_packet_handlers, sizeof(PacketGroupHandler)*MAX_PACKET_GROUPS, 0);

    // initialize xbee

    if(xbee_init() == -1) {

        return WL_ERROR_INIT_FAILED;

    }

    // do we need a timer handler?

    //rtc_init(HALF_SECOND, &timer_handler); 

    return WL_SUCCESS;

}

/**

 * termination function:

 * end xbee communication, deregister all handlers, etc

 *

 * @return 0 on success, or error code

 **/

int8_t wl_terminate(void) {

    // check to see if wireless library has been initialized

    if(init_flag == INIT_NO) {

        return WL_ERROR_LIBRARY_NOT_INITD;

    }

    // reset packet handler array

    memset(wl_packet_handlers, sizeof(PacketGroupHandler)*MAX_PACKET_GROUPS, 0);

    if(xbee_terminate() != WL_SUCCESS) {

        return WL_ERROR_TERMINATION_FAILED;

    }

    return WL_SUCCESS;

}

/**

 * function to register new packet handlers (for non-default groups only)

 *

 * @param group the packet group number of the packets to handle with this function

 * @param func the function pointer to the user-specified packet handler

 * @param priority flag to set the priority of the function handler

 *

 * @return 0 on success, or error code

 **/

int8_t wl_register_handler(uint8_t group, FNPTR, uint8_t priority) {

    // check to see if wireless library has been initialized

    if(init_flag == INIT_NO) {

        return WL_ERROR_LIBRARY_NOT_INITD;

    }

    // packet group number exceeds available packets groups   

    // or packet group handler already exists

    if(group >= MAX_PACKET_GROUPS || group == 0

        || wl_packet_handlers[group].FUNC != NULL) {

        return WL_ERROR_FAILED_REGISTRATION;

    }

    // save packet handler function pointer and priority

    wl_packet_handlers[group].FUNC = FUNC;

    wl_packet_handlers[group].priority = priority;

    return WL_SUCCESS;

}

/**

 * function to unregister existing packet handlers (for non-default groups only)

 *

 * @param group the packet group number of the handler to unregister

 *

 * @return 0 on success, or error code

 **/

int8_t wl_unregister_handler(uint8_t group) {

    // check to see if wireless library has been initialized

    if(init_flag == INIT_NO) {

        return WL_ERROR_LIBRARY_NOT_INITD;

    }

    // packet group number exceeds available packets groups

    if(group >= MAX_PACKET_GROUPS) {

        return WL_ERROR_FAILED_UNREGISTRATION;

    }

    // packet group handler does not exists

    if(wl_packet_handlers[group].FUNC == NULL) {

        return WL_ERROR_FAILED_UNREGISTRATION;

    }

    // clear packet group information

    wl_packet_handlers[group].FUNC = NULL;

    wl_packet_handlers[group].priority = NORMAL_PRIORITY;

    return WL_SUCCESS;

}

/**@} **/ //end defgroup

// Define all private functions down here