keytag.c

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#include "keytag.h"

#include <kern/kfile.h>

#include <drv/timer.h>
#include <drv/ser.h>

#include <cfg/macros.h>
#include <cfg/debug.h>

static void keytag_clearPkt(struct TagPacket *pkt)
{
    pkt->sync = false;
    pkt->len = 0;
}

void keytag_init(struct TagPacket *pkt, struct KFile *comm, struct KFile *tag)
{
    keytag_clearPkt(pkt);
    pkt->host = comm;
    pkt->tag = tag;
}

void keytag_poll(struct TagPacket *pkt)
{
    int c;

    /* Get all chars from buffer */
    while ((c = kfile_getc(pkt->tag)) != EOF)
    {
        /* Search for STX char in received chars */
        if (c == TAG_STX)
        {
            /* When STX is found a new packet begins */
            if (pkt->sync)
                kprintf("TAG double sync!\n");
            keytag_clearPkt(pkt);
            pkt->sync = true;
        }
        else if (pkt->sync)
        {
            /* Check for end of packet */
            if (c == TAG_ETX)
            {
                pkt->buf[TAG_MAX_PRINT_CHARS] = '\x0';
                /* Write read TAG on communication serial */
                kfile_printf(pkt->host, "tag %s", pkt->buf);
                pkt->sync = false;
            }
            else
            {
                /* Check for buffer overflow */
                if (pkt->len >= TAG_MAX_LEN)
                {
                    kprintf("TAG buffer overflow\n");
                    pkt->sync = false;
                }
                else
                {
                    /* Add every char after STX to tag reading buffer */
                    if (pkt->sync)
                    {
                        pkt->buf[pkt->len] = c;
                        pkt->len++;
                    }
                }
            }
        }
    }
    if (kfile_error(pkt->tag) != 0)
    {
        kprintf("Error %08x\n", kfile_error(pkt->tag));
        kfile_clearerr(pkt->tag);
    }

}