/*-----------------------------------------------------------------------
  The ECB is a rack controller from Risoe based on a Z80 processor. 
  This module provides some functions for communicating with such a
  device. This is the implementation file. 

  WARNING: This contains code which may be endian dependent!

  copyright: see file COPYRIGHT

  Mark Koennecke, January 2002, with some bits taken from the original 
  tascom code.
  -------------------------------------------------------------------------*/
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <tcl.h>
#include "fortify.h"
#include "sics.h"
#include "ecb.h"
#include "ecb.i"
/*------------- private defines and error codes ------------------------*/
#define ACKN ('\6') /* Acknowledge character */
#define READ_BYTES 3
#define WRITE_BYTES 4
#define ECB_BYTES 65536L

typedef union           /* Used to swap bytes in 'address' and 'byte_count' */
  {
    unsigned short word;
    struct
      { 
        unsigned char msb;      /* Most significant byte */
        unsigned char lsb;      /* Least significant byte */
      }b;
  }Swap;
/* ------- error codes */
#define ECBILLEGALFUNC -100
#define ECBOVERFLOW    -101

/*----------------------------------------------------------------------*/
static int ecbSendFunc(pECB self, int func){
  unsigned char function, response;
  int count, status;

  /*
    send function code
  */
  function = (unsigned char)func;
  count = 1;
  status = GPIBsend(self->gpib,self->ecbDeviceID,&function,count);
  if(status < 0){
    self->lastError = status;
    return 0;
  }

  /*
    read acknowledge byte
  */
  status = GPIBread(self->gpib,self->ecbDeviceID,&response,count);
  if(status < 0){
    self->lastError = status;
    return 0;
  }
  if(response != ACKN){
    self->lastError = ECBILLEGALFUNC;
    return 0;
  }
  return 1;
}
/*-----------------------------------------------------------------------*/
int ecbExecute(pECB self, int func, Z80_reg in, Z80_reg *out){
  int count, status;

  assert(self != NULL);
  assert(self->gpib != NULL);
  self->lastError = 0;

  /*
    send function code
  */
  status = ecbSendFunc(self,func);
  if(status <= 0){
    return status;
  }

  /*
    send input register 
  */
  count = 4;
  status = GPIBsend(self->gpib,self->ecbDeviceID, &in, count);
  if(status < 0){
    self->lastError = status;
    return 0;
  }

  /*
    read result register
  */
  status = GPIBread(self->gpib,self->ecbDeviceID, out, count);
  if(status < 0){
    self->lastError = status;
    return 0;
  }

  return 1;  
}
/*----------------------------------------------------------------------*/
static int ecbPrepareIO(pECB self, int func, unsigned short address,
			unsigned short byteCount){
  Swap save, adr, count;
  int status, bytes;

  if(byteCount > ECB_BYTES){
    self->lastError = ECBOVERFLOW;
    return 0;
  }

  /*
    Swap address and byteCount?? This may be a portability issue!
    This may not be necessary on some platforms
  */
  save.word = address;            /* Swap address bytes */
  adr.b.lsb = save.b.msb;
  adr.b.msb = save.b.lsb;
  save.word = byteCount;     /* Swap byte count bytes */
  count.b.lsb = save.b.msb;
  count.b.msb = save.b.lsb;

  status = ecbSendFunc(self,func);
  if(status <= 0){
    return status;
  }

  /*
    send address 
  */
  bytes = 2;
  status = GPIBsend(self->gpib,self->ecbDeviceID,&adr,bytes);
  if(status < 0){
    self->lastError = status;
    return 0;
  }

  /*
    send byte count
  */
  status = GPIBsend(self->gpib,self->ecbDeviceID,&count,bytes);
  if(status < 0){
    self->lastError = status;
    return 0;
  }

  return 1;
}
/*-----------------------------------------------------------------------*/
int ecbRead(pECB self, unsigned short address, 
	    void *buffer, int byteCount){

  int status, count;

  assert(self != NULL);
  assert(self->gpib != NULL);
  self->lastError = 0;

  status = ecbPrepareIO(self,READ_BYTES,address,(unsigned short)byteCount);
  if(status <= 0){
    return 0;
  }

  /*
    actual read
  */
  status = GPIBread(self->gpib,self->ecbDeviceID, buffer, byteCount);
  if(status  < 0){
    self->lastError = status;
    return 0;
  }

  return 1;
}
/*----------------------------------------------------------------------*/
int ecbWrite(pECB self, unsigned short address, 
	    void *buffer, int byteCount){

  int status, count;

  assert(self != NULL);
  assert(self->gpib != NULL);
  self->lastError = 0;

  status = ecbPrepareIO(self,WRITE_BYTES,address,(unsigned short)byteCount);
  if(status <= 0){
    return 0;
  }

  /*
    actual read
  */
  status = GPIBsend(self->gpib,self->ecbDeviceID, buffer, byteCount);
  if(status  < 0){
    self->lastError = status;
    return 0;
  }

  return 1;
}
/*-----------------------------------------------------------------------*/
void ecbErrorDescription(pECB self, char *buffer, int maxBuffer){
  int positive;

  switch(self->lastError){
  case ECBILLEGALFUNC:
    strncpy(buffer,"Illegal ECB function called",maxBuffer);
    return;
  case ECBOVERFLOW:
    strncpy(buffer,
     "You tried to copy more then 64K onto the poor ECB, REFUSED!",
	    maxBuffer);
    return;
  }

  /*
    GPIB error codes
  */
  GPIBerrorDescription(self->gpib,self->lastError,buffer, maxBuffer);
}
/*----------------------------------------------------------------------*/
void ecbClear(pECB self){
  GPIBclear(self->gpib, self->ecbDeviceID);
}
/*-----------------------------------------------------------------------*/
int fixECBError(pECB self){
  int pos;

  switch(self->lastError){
  case ECBILLEGALFUNC:
  case ECBOVERFLOW:
    return HWFault;
  }

  /*
    GPIB error
  */
  pos = -self->lastError;
  switch(pos){
  case GPIBEABO:
    return HWRedo;
  default:
    return HWFault;
  }
}
/*------------------------------------------------------------------------*/
int ECBAction(SConnection *pCon, SicsInterp *pSics, void *pData,
	      int argc, char *argv[]){
  pECB self = (pECB)pData;
  Z80_reg in, out;
  char pBuffer[80], pError[132];
  int status, iVal, func;

  assert(self != NULL);

  /*
    Only managers will be allowed to wrestle directly with ECB
    controllers.
  */
  if(!SCMatchRights(pCon,usMugger)){
    return 0;
  }

  if(argc < 2){
    SCWrite(pCon,"ERROR: keyword required for ECB",eError);
    return 0;
  }

  strtolower(argv[1]);
  if(strcmp(argv[1],"func") == 0){
    if(argc < 7){
      SCWrite(pCon,"ERROR: require function code and four register values",
	      eError);
      return 0;
    }
    status = Tcl_GetInt(pSics->pTcl, argv[2],&func);
    if(status != TCL_OK){
      SCWrite(pCon,"ERROR: failed to convert argument to int",eError);
      return 0;
    }
    status = Tcl_GetInt(pSics->pTcl, argv[3],&iVal);
    if(status != TCL_OK){
      SCWrite(pCon,"ERROR: failed to convert argument to int",eError);
      return 0;
    }
    in.d = (unsigned char)iVal;
    status = Tcl_GetInt(pSics->pTcl, argv[4],&iVal);
    if(status != TCL_OK){
      SCWrite(pCon,"ERROR: failed to convert argument to int",eError);
      return 0;
    }
    in.e = (unsigned char)iVal;
    status = Tcl_GetInt(pSics->pTcl, argv[5],&iVal);
    if(status != TCL_OK){
      SCWrite(pCon,"ERROR: failed to convert argument to int",eError);
      return 0;
    }
    in.b = (unsigned char)iVal;
    status = Tcl_GetInt(pSics->pTcl, argv[6],&iVal);
    if(status != TCL_OK){
      SCWrite(pCon,"ERROR: failed to convert argument to int",eError);
      return 0;
    }
    in.c = (unsigned char)iVal;

    status = ecbExecute(self,func,in,&out);
    if(status != 1){
      ecbErrorDescription(self,pBuffer,79);
      sprintf(pError,"ERROR: %s", pBuffer);
      SCWrite(pCon,pError,eError);
      return 0;
    }
    sprintf(pBuffer,"%x %x %x %x",
	    out.d, out.e, out.c, out.c);
    SCWrite(pCon,pBuffer,eValue);
    return 1;
  } else {
    SCWrite(pCon,"ERROR: ECB does not understand keyword", eError);
    return 0;
  }
}
/*---------------------------------------------------------------------*/
int ecbAssignEncoder(pECB self, int encoder, int motorNumber){

  if(encoder <= 0 || encoder > 3){
    return 0;
  }

  self->encoder[encoder-1] = motorNumber;
  self->encoderDirty = 1;
  return 1;
}
/*----------------------------------------------------------------------*/
int ecbLoadEncoder(pECB self){
  Z80_reg in, out;
  int status;

  if(self->encoderDirty != 1){
    /*
      no need to do it if no change 
    */
    return 1;
  }

  if(self->encoder[0] != 0){
    in.d = self->encoder[0];
  }else {
    in.d = 0;
  }
  if(self->encoder[1] != 0){
    in.e = self->encoder[1];
  }else {
    in.e = 0;
  }
  if(self->encoder[2] != 0){
    in.b = self->encoder[2];
  }else {
    in.b = 0;
  }
  in.c = 1;

  status = ecbExecute(self,152,in,&out);
  return status;
}
/*-----------------------------------------------------------------------*/
void ECBKill(void *pData){
  pECB self = (pECB)pData;
  
  if(self == NULL){
    return;
  }

  /*
    Detaching here may be dangerous: If the GPIB has been deleted first, 
    this makes a core dump. Best is the GPIB keeps a list of attached
    things and cleans them itself.
    
    GPIBdetach(self->gpib,self->ecbDeviceID);
  */  
  if(self->pDes){
    DeleteDescriptor(self->pDes);
  }
  free(self);
}
/*----------------------------------------------------------------------
MakeECB name gpibcontroller boardNo gpib-address
  -----------------------------------------------------------------------*/
int MakeECB(SConnection *pCon, SicsInterp *pSics, void *pData,
	    int argc, char *argv[]){
  pECB self = NULL;
  int address, status, boardNo;
  pGPIB gpib = NULL;
  char pError[132];

  /*
    we need a name, the GPIB controller and an address on the GPIB bus for 
    the ECB  as arguments
  */
  if(argc < 5){
    SCWrite(pCon,"ERROR: insufficient arguments to MakeECB",eError);
    return 0;
  }
  gpib = FindCommandData(pSics,argv[2],"GPIB");
  if(gpib == NULL){
    sprintf(pError,"ERROR: no GPIB controller %s found", argv[2]);
    SCWrite(pCon,pError,eError);
    return 0;
  }
  status = Tcl_GetInt(pSics->pTcl,argv[3], &boardNo);
  if(status != TCL_OK){
    sprintf(pError,"ERROR: failed to convert %s to integer",argv[3]);
    SCWrite(pCon,pError,eError);
    return 0;
  }
  status = Tcl_GetInt(pSics->pTcl,argv[4], &address);
  if(status != TCL_OK){
    sprintf(pError,"ERROR: failed to convert %s to integer",argv[4]);
    SCWrite(pCon,pError,eError);
    return 0;
  }
  if(address < 0 || address > 30){
    SCWrite(pCon,"ERROR: invalid GPIB address specified",eError);
    return 0;
  }

  self = (pECB)malloc(sizeof(ECB));
  if(self == NULL){
    SCWrite(pCon,"ERROR: no memory to allocate ECB",eError);
    return 0;
  }
  memset(self,0,sizeof(ECB));
  self->pDes = CreateDescriptor("ECB");
  if(self->pDes == NULL){
    SCWrite(pCon,"ERROR: no memory to allocate ECB",eError);
    return 0;
  }
  self->gpib = gpib;
  self->boardNumber = boardNo;
  self->ecbAddress = address;
  self->ecbDeviceID =GPIBattach(self->gpib,self->boardNumber, 
				self->ecbAddress,0,
				13,0,1);
  if(self->ecbDeviceID <= 0){
    SCWrite(pCon,"ERROR: failed to initialize ECB connection",
	    eError);
    ECBKill(self);
    return 0;
  }
  AddCommand(pSics,argv[1],ECBAction,ECBKill,self);
  return 1;
}