bacnet_stack/ports/pic18f6720/dlmstp.c

/**************************************************************************
 *
 * Copyright (C) 2006 Steve Karg <skarg@users.sourceforge.net>
 *
 * SPDX-License-Identifier: MIT
 *
 *********************************************************************/
#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#if PRINT_ENABLED
#include <stdio.h>
#endif
#include "bacnet/bacdef.h"
#include "bacnet/datalink/mstp.h"
#include "bacnet/datalink/dlmstp.h"
#include "rs485.h"
#include "bacnet/npdu.h"
#include "bacnet/basic/services.h"

/* Number of MS/TP Packets Rx/Tx */
uint16_t MSTP_Packets = 0;

/* receive buffer */
#pragma udata MSTP_RxData
static DLMSTP_PACKET Receive_Buffer;
/* temp buffer for NPDU insertion */
/* local MS/TP port data - shared with RS-485 */
#pragma udata MSTP_PortData
volatile struct mstp_port_struct_t MSTP_Port;
#pragma udata

#define INCREMENT_AND_LIMIT_UINT16(x) \
    {                                 \
        if (x < 0xFFFF)               \
            x++;                      \
    }

void dlmstp_millisecond_timer(void)
{
    INCREMENT_AND_LIMIT_UINT16(MSTP_Port.SilenceTimer);
}

void dlmstp_reinit(void)
{
    RS485_Reinit();
    dlmstp_set_my_address(DEFAULT_MAC_ADDRESS);
    dlmstp_set_max_info_frames(DEFAULT_MAX_INFO_FRAMES);
    dlmstp_set_max_master(DEFAULT_MAX_MASTER);
}

void dlmstp_init(void)
{
    uint8_t data;

    /* initialize buffer */
    Receive_Buffer.ready = false;
    Receive_Buffer.pdu_len = 0;
    /* initialize hardware */
    RS485_Initialize();
    MSTP_Port.InputBuffer = &Receive_Buffer.pdu[0];
    MSTP_Init(&MSTP_Port);
}

void dlmstp_cleanup(void)
{
    /* nothing to do for static buffers */
}

/* returns number of bytes sent on success, zero on failure */
int dlmstp_send_pdu(BACNET_ADDRESS *dest, /* destination address */
    BACNET_NPDU_DATA *npdu_data, /* network information */
    uint8_t *pdu, /* any data to be sent - may be null */
    unsigned pdu_len)
{ /* number of bytes of data */
    int bytes_sent = 0;
    unsigned npdu_len = 0;
    uint8_t frame_type = 0;
    BACNET_ADDRESS src;
    unsigned i = 0; /* loop counter */

    if (MSTP_Port.TxReady == false) {
        if (npdu_data->data_expecting_reply)
            MSTP_Port.TxFrameType = FRAME_TYPE_BACNET_DATA_EXPECTING_REPLY;
        else
            MSTP_Port.TxFrameType = FRAME_TYPE_BACNET_DATA_NOT_EXPECTING_REPLY;

        /* load destination MAC address */
        if (dest && dest->mac_len) {
            MSTP_Port.TxDestination = dest->mac[0];
        } else {
            /* mac_len = 0 is a broadcast address */
            MSTP_Port.TxDestination = MSTP_BROADCAST_ADDRESS;
        }
        dlmstp_get_my_address(&src);
        if ((DLMSTP_HEADER_MAX + pdu_len) > DLMSTP_MPDU_MAX) {
            return -4;
        }
        bytes_sent = MSTP_Create_Frame((uint8_t *)&MSTP_Port.TxBuffer[0],
            sizeof(MSTP_Port.TxBuffer), MSTP_Port.TxFrameType,
            MSTP_Port.TxDestination, MSTP_Port.This_Station, pdu, pdu_len);
        MSTP_Port.TxLength = bytes_sent;
        MSTP_Port.TxReady = true;
        MSTP_Packets++;
    }

    return bytes_sent;
}

void dlmstp_task(void)
{
    bool bytes_remaining;
    bool received_frame;

    /* only do receive state machine while we don't have a frame */
    if ((MSTP_Port.ReceivedValidFrame == false) &&
        (MSTP_Port.ReceivedInvalidFrame == false)) {
        do {
            bytes_remaining = RS485_Check_UART_Data(&MSTP_Port);
            MSTP_Receive_Frame_FSM(&MSTP_Port);
            received_frame =
                MSTP_Port.ReceivedValidFrame || MSTP_Port.ReceivedInvalidFrame;
            if (received_frame)
                break;
        } while (bytes_remaining);
    }
    /* only do master state machine while rx is idle */
    if (MSTP_Port.receive_state == MSTP_RECEIVE_STATE_IDLE) {
        if (MSTP_Port.This_Station <= DEFAULT_MAX_MASTER) {
            while (MSTP_Master_Node_FSM(&MSTP_Port)) {
                /* do nothing while some states fast transition */
            };
        }
    }
    /* see if there is a packet available, and a place
       to put the reply (if necessary) and process it */
    if (Receive_Buffer.ready && !MSTP_Port.TxReady) {
        if (Receive_Buffer.pdu_len) {
            MSTP_Packets++;
            npdu_handler(&Receive_Buffer.address, &Receive_Buffer.pdu[0],
                Receive_Buffer.pdu_len);
        }
        Receive_Buffer.ready = false;
    }

    return;
}

void dlmstp_fill_bacnet_address(BACNET_ADDRESS *src, uint8_t mstp_address)
{
    int i = 0;

    if (mstp_address == MSTP_BROADCAST_ADDRESS) {
        /* mac_len = 0 if broadcast address */
        src->mac_len = 0;
        src->mac[0] = 0;
    } else {
        src->mac_len = 1;
        src->mac[0] = mstp_address;
    }
    /* fill with 0's starting with index 1; index 0 filled above */
    for (i = 1; i < MAX_MAC_LEN; i++) {
        src->mac[i] = 0;
    }
    src->net = 0;
    src->len = 0;
    for (i = 0; i < MAX_MAC_LEN; i++) {
        src->adr[i] = 0;
    }
}

/* for the MS/TP state machine to use for putting received data */
uint16_t dlmstp_put_receive(uint8_t src, /* source MS/TP address */
    uint8_t *pdu, /* PDU data */
    uint16_t pdu_len)
{ /* amount of PDU data */
    /* PDU is already in the Receive_Buffer */
    dlmstp_fill_bacnet_address(&Receive_Buffer.address, src);
    Receive_Buffer.pdu_len = pdu_len;
    Receive_Buffer.ready = true;
}

void dlmstp_set_my_address(uint8_t mac_address)
{
    /* Master Nodes can only have address 0-127 */
    if (mac_address <= 127) {
        MSTP_Port.This_Station = mac_address;
        /* FIXME: implement your data storage */
        /* I2C_Write_Byte(
           EEPROM_DEVICE_ADDRESS,
           mac_address,
           EEPROM_MSTP_MAC_ADDR); */
        if (mac_address > MSTP_Port.Nmax_master)
            dlmstp_set_max_master(mac_address);
    }

    return;
}

uint8_t dlmstp_my_address(void)
{
    return MSTP_Port.This_Station;
}

/* This parameter represents the value of the Max_Info_Frames property of */
/* the node's Device object. The value of Max_Info_Frames specifies the */
/* maximum number of information frames the node may send before it must */
/* pass the token. Max_Info_Frames may have different values on different */
/* nodes. This may be used to allocate more or less of the available link */
/* bandwidth to particular nodes. If Max_Info_Frames is not writable in a */
/* node, its value shall be 1. */
void dlmstp_set_max_info_frames(uint8_t max_info_frames)
{
    if (max_info_frames >= 1) {
        MSTP_Port.Nmax_info_frames = max_info_frames;
        /* FIXME: implement your data storage */
        /* I2C_Write_Byte(
           EEPROM_DEVICE_ADDRESS,
           (uint8_t)max_info_frames,
           EEPROM_MSTP_MAX_INFO_FRAMES_ADDR); */
    }

    return;
}

unsigned dlmstp_max_info_frames(void)
{
    return MSTP_Port.Nmax_info_frames;
}

/* This parameter represents the value of the Max_Master property of the */
/* node's Device object. The value of Max_Master specifies the highest */
/* allowable address for master nodes. The value of Max_Master shall be */
/* less than or equal to 127. If Max_Master is not writable in a node, */
/* its value shall be 127. */
void dlmstp_set_max_master(uint8_t max_master)
{
    if (max_master <= 127) {
        if (MSTP_Port.This_Station <= max_master) {
            MSTP_Port.Nmax_master = max_master;
            /* FIXME: implement your data storage */
            /* I2C_Write_Byte(
               EEPROM_DEVICE_ADDRESS,
               max_master,
               EEPROM_MSTP_MAX_MASTER_ADDR); */
        }
    }

    return;
}

uint8_t dlmstp_max_master(void)
{
    return MSTP_Port.Nmax_master;
}

void dlmstp_get_my_address(BACNET_ADDRESS *my_address)
{
    int i = 0; /* counter */

    my_address->mac_len = 1;
    my_address->mac[0] = MSTP_Port.This_Station;
    my_address->net = 0; /* local only, no routing */
    my_address->len = 0;
    for (i = 0; i < MAX_MAC_LEN; i++) {
        my_address->adr[i] = 0;
    }

    return;
}

void dlmstp_get_broadcast_address(BACNET_ADDRESS *dest)
{ /* destination address */
    int i = 0; /* counter */

    if (dest) {
        dest->mac_len = 1;
        dest->mac[0] = MSTP_BROADCAST_ADDRESS;
        dest->net = BACNET_BROADCAST_NETWORK;
        dest->len = 0; /* always zero when DNET is broadcast */
        for (i = 0; i < MAX_MAC_LEN; i++) {
            dest->adr[i] = 0;
        }
    }

    return;
}