ownetu.c

sdcc是为51等小型嵌入式cpu设计的c语言编译器支持数种不同类型的cpu

#define DEBUG_OW_NETU 0
#if DEBUG_OW_NETU
#include <stdio.h>
#endif
//---------------------------------------------------------------------------
// Copyright (C) 2000 Dallas Semiconductor Corporation, All Rights Reserved.
// 
// 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 DALLAS SEMICONDUCTOR 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.
// 
// Except as contained in this notice, the name of Dallas Semiconductor 
// shall not be used except as stated in the Dallas Semiconductor 
// Branding Policy. 
//---------------------------------------------------------------------------
//
//  owNetU.C - Network functions for 1-Wire Net devices
//             using the DS2480/DS2480B (U) serial interface chip. 
//
//  Version: 2.00
//
//           1.02 -> 1.03  Removed caps in #includes for Linux capatibility
//           1.03 -> 2.00  Changed 'MLan' to 'ow'. Added support for 
//                         multiple ports.
//

#include "ownet.h"
#include "ds2480.h"

// globally used 
uchar SerialNum[MAX_PORTNUM][8];

// local variables for this module to hold search state information
static int LastDiscrepancy[MAX_PORTNUM];
static int LastFamilyDiscrepancy[MAX_PORTNUM];
static int LastDevice[MAX_PORTNUM];

//--------------------------------------------------------------------------
// The 'owFirst' finds the first device on the 1-Wire Net  This function 
// contains one parameter 'alarm_only'.  When 
// 'alarm_only' is TRUE (1) the find alarm command 0xEC is 
// sent instead of the normal search command 0xF0.
// Using the find alarm command 0xEC will limit the search to only
// 1-Wire devices that are in an 'alarm' state. 
//
// 'portnum'    - number 0 to MAX_PORTNUM-1.  This number is provided to
//                indicate the symbolic port number.
// 'do_reset'   - TRUE (1) perform reset before search, FALSE (0) do not
//                perform reset before search. 
// 'alarm_only' - TRUE (1) the find alarm command 0xEC is 
//                sent instead of the normal search command 0xF0
//
// Returns:   TRUE (1) : when a 1-Wire device was found and it's 
//                       Serial Number placed in the global SerialNum
//            FALSE (0): There are no devices on the 1-Wire Net.
// 
int owFirst(int portnum, int do_reset, int alarm_only)
{
   // reset the search state
   LastDiscrepancy[portnum] = 0;
   LastDevice[portnum] = FALSE;
   LastFamilyDiscrepancy[portnum] = 0; 

   return owNext(portnum, do_reset, alarm_only);
}

//--------------------------------------------------------------------------
// The 'owNext' function does a general search.  This function
// continues from the previos search state. The search state
// can be reset by using the 'owFirst' function.
// This function contains one parameter 'alarm_only'.  
// When 'alarm_only' is TRUE (1) the find alarm command 
// 0xEC is sent instead of the normal search command 0xF0.
// Using the find alarm command 0xEC will limit the search to only
// 1-Wire devices that are in an 'alarm' state. 
//
// 'portnum'    - number 0 to MAX_PORTNUM-1.  This number was provided to
//                OpenCOM to indicate the port number.
// 'do_reset'   - TRUE (1) perform reset before search, FALSE (0) do not
//                perform reset before search. 
// 'alarm_only' - TRUE (1) the find alarm command 0xEC is 
//                sent instead of the normal search command 0xF0
//
// Returns:   TRUE (1) : when a 1-Wire device was found and it's 
//                       Serial Number placed in the global SerialNum
//            FALSE (0): when no new device was found.  Either the
//                       last search was the last device or there
//                       are no devices on the 1-Wire Net.
// 
int owNext(int portnum, int do_reset, int alarm_only)
{
   int i,tmp_last_desc,pos;
   uchar tmp_serial_num[8];
   uchar readbuffer[20],sendpacket[40];
   int sendlen=0;
   uchar lastcrc8;

   // if the last call was the last one 
   if (LastDevice[portnum])
   {
      // reset the search
      LastDiscrepancy[portnum] = 0;
      LastDevice[portnum] = FALSE;
      LastFamilyDiscrepancy[portnum] = 0;  
#if DEBUG_OW_NETU
      printf ("owNext: no (more) devices\n");
#endif
      return FALSE;
   }

   // check if reset first is requested
   if (do_reset)
   {
      // reset the 1-wire 
      // if there are no parts on 1-wire, return FALSE
      if (!owTouchReset(portnum))
      {
         // reset the search
         LastDiscrepancy[portnum] = 0;        
         LastFamilyDiscrepancy[portnum] = 0; 
         return FALSE;
      }
   }

   // build the command stream
   // call a function that may add the change mode command to the buff
   // check if correct mode 
   if (UMode[portnum] != MODSEL_DATA)
   {
      UMode[portnum] = MODSEL_DATA;
      sendpacket[sendlen++] = MODE_DATA;
   }

   // search command
   if (alarm_only)
      sendpacket[sendlen++] = 0xEC; // issue the alarming search command 
   else
      sendpacket[sendlen++] = 0xF0; // issue the search command 

   // change back to command mode
   UMode[portnum] = MODSEL_COMMAND;
   sendpacket[sendlen++] = MODE_COMMAND;

   // search mode on
   sendpacket[sendlen++] = (uchar)(CMD_COMM | FUNCTSEL_SEARCHON | USpeed[portnum]);

   // change back to data mode
   UMode[portnum] = MODSEL_DATA;
   sendpacket[sendlen++] = MODE_DATA;

   // set the temp Last Descrep to none
   tmp_last_desc = 0xFF;  

   // add the 16 bytes of the search
   pos = sendlen;
   for (i = 0; i < 16; i++)
      sendpacket[sendlen++] = 0;

   // only modify bits if not the first search
   if (LastDiscrepancy[portnum] != 0xFF)
   {
      // set the bits in the added buffer
      for (i = 0; i < 64; i++)
      {
         // before last discrepancy
         if (i < (LastDiscrepancy[portnum] - 1)) 
               bitacc(WRITE_FUNCTION,
                   bitacc(READ_FUNCTION,0,i,&SerialNum[portnum][0]), 
                   (short)(i * 2 + 1), 
                   &sendpacket[pos]);
         // at last discrepancy
         else if (i == (LastDiscrepancy[portnum] - 1)) 
                bitacc(WRITE_FUNCTION,1, 
                   (short)(i * 2 + 1), 
                   &sendpacket[pos]);
         // after last discrepancy so leave zeros
      }
   }

   // change back to command mode
   UMode[portnum] = MODSEL_COMMAND;
   sendpacket[sendlen++] = MODE_COMMAND;

   // search OFF
   sendpacket[sendlen++] = (uchar)(CMD_COMM | FUNCTSEL_SEARCHOFF | USpeed[portnum]);

   // flush the buffers
   FlushCOM(portnum);

   // send the packet 
   if (WriteCOM(portnum,sendlen,sendpacket)) 
   {
      // read back the 1 byte response 
      if (ReadCOM(portnum,17,readbuffer) == 17)
      {
         // interpret the bit stream
         for (i = 0; i < 64; i++)
         {
            // get the SerialNum bit
            bitacc(WRITE_FUNCTION,
                   bitacc(READ_FUNCTION,0,(short)(i * 2 + 1),&readbuffer[1]),
                   i,
                   &tmp_serial_num[0]);
            // check LastDiscrepancy
            if ((bitacc(READ_FUNCTION,0,(short)(i * 2),&readbuffer[1]) == 1) &&
                (bitacc(READ_FUNCTION,0,(short)(i * 2 + 1),&readbuffer[1]) == 0))
            {
               tmp_last_desc = i + 1;  
               // check LastFamilyDiscrepancy
               if (i < 8)
                  LastFamilyDiscrepancy[portnum] = i + 1; 
            }
         }

         // do dowcrc
         setcrc8(portnum,0);
         for (i = 0; i < 8; i++)
            lastcrc8 = docrc8(portnum,tmp_serial_num[i]);

         // check results 
         if ((lastcrc8 != 0) || (LastDiscrepancy[portnum] == 63) || (tmp_serial_num[0] == 0))
         {
            // error during search 
            // reset the search
            LastDiscrepancy[portnum] = 0;
            LastDevice[portnum] = FALSE;
            LastFamilyDiscrepancy[portnum] = 0;        
#if DEBUG_OW_NETU
	    printf ("owNext: check results failed\n");
#endif
            return FALSE;
         }
         // successful search
         else
         {
            // check for lastone
            if ((tmp_last_desc == LastDiscrepancy[portnum]) || (tmp_last_desc == 0xFF))
               LastDevice[portnum] = TRUE;

            // copy the SerialNum to the buffer
            for (i = 0; i < 8; i++)
               SerialNum[portnum][i] = tmp_serial_num[i];
         
            // set the count
            LastDiscrepancy[portnum] = tmp_last_desc;
            return TRUE;
         }
      } else {
#if DEBUG_OW_NETU
	printf ("owNext: ReadCOM failed\n");
#endif
      }
   } else {
#if DEBUG_OW_NETU
     printf ("owNext: WriteCOM failed\n");
#endif
   }

   // an error occured so re-sync with DS2480
   DS2480Detect(portnum);

   // reset the search
   LastDiscrepancy[portnum] = 0;
   LastDevice[portnum] = FALSE;
   LastFamilyDiscrepancy[portnum] = 0;          

   return FALSE;
}

//--------------------------------------------------------------------------
// The 'owSerialNum' function either reads or sets the SerialNum buffer 
// that is used in the search functions 'owFirst' and 'owNext'.