Subversion Repositories openrisc

//==========================================================================
//
//      devs/watchdog/powerpc/mpc5xx/watchdog_mpc5xx.cxx
//
//      Watchdog implementation for MPC5XX
//
//==========================================================================
// ####ECOSGPLCOPYRIGHTBEGIN####                                            
// -------------------------------------------                              
// This file is part of eCos, the Embedded Configurable Operating System.   
// Copyright (C) 1998, 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
//
// eCos is free software; you can redistribute it and/or modify it under    
// the terms of the GNU General Public License as published by the Free     
// Software Foundation; either version 2 or (at your option) any later      
// version.                                                                 
//
// eCos is distributed in the hope that it will be useful, but WITHOUT      
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or    
// FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License    
// for more details.                                                        
//
// You should have received a copy of the GNU General Public License        
// along with eCos; if not, write to the Free Software Foundation, Inc.,    
// 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.            
//
// As a special exception, if other files instantiate templates or use      
// macros or inline functions from this file, or you compile this file      
// and link it with other works to produce a work based on this file,       
// this file does not by itself cause the resulting work to be covered by   
// the GNU General Public License. However the source code for this file    
// must still be made available in accordance with section (3) of the GNU   
// General Public License v2.                                               
//
// This exception does not invalidate any other reasons why a work based    
// on this file might be covered by the GNU General Public License.         
// -------------------------------------------                              
// ####ECOSGPLCOPYRIGHTEND####                                              
//==========================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):    Bob Koninckx
// Contributors: Bob Koninckx
// Date:         2003-05-18
// Purpose:      Watchdog class implementation
// Description:  Contains an implementation of the Watchdog class for use
//               with the mpc5xx watchdog timer.
//
//####DESCRIPTIONEND####
//
//==========================================================================
 
#include <pkgconf/system.h>             // system configuration file
#include <pkgconf/watchdog.h>           // configuration for this package
 
#include <cyg/infra/cyg_trac.h>         // tracing macros
 
#include <cyg/hal/hal_io.h>             // IO register access
#include <cyg/hal/hal_arch.h>           // Register definitions
 
#include <cyg/io/watchdog.hxx>          // watchdog API
 
// -------------------------------------------------------------------------
// MPC5xx SYPCR register bit definitions
#define MPC5XX_SYPCR_SWTC 0xffff0000
#define MPC5XX_SYPCR_SWP  0x00000001
#define MPC5XX_SYPCR_SWRI 0x00000002
#define MPC5XX_SYPCR_SWE  0x00000004
#define MPC5XX_SYPCR_SWF  0x00000008
 
// -------------------------------------------------------------------------
// Constructor
 
void
Cyg_Watchdog::init_hw(void)
{
    CYG_REPORT_FUNCTION();
 
    cyg_uint32 sypcr;
	HAL_READ_UINT32(CYGARC_REG_IMM_SYPCR, sypcr);
 
    resolution = (sypcr & MPC5XX_SYPCR_SWTC) >> 16;
	if(sypcr & MPC5XX_SYPCR_SWP)
	  resolution *= 2048;
 
	// Now we have it in ticks, convert to nanoseconds
	// This holds for a system clock of 40 Mhz (25 nanosecond ticks) which is normal
	// for the MPC5xx
	resolution *= 25;
 
    CYG_REPORT_RETURN();
}
 
// -------------------------------------------------------------------------
// Start the watchdog running.
// On powerpc, the watchdog is enabled by default. If the watchdog package
// is present, board setup does not disable it, so, nothing special to be
// done here.
void
Cyg_Watchdog::start(void)
{
    CYG_REPORT_FUNCTION();
 
    CYG_REPORT_RETURN();
}
 
// -------------------------------------------------------------------------
// Reset watchdog timer. This needs to be called regularly to prevent
// the watchdog firing.
 
void
Cyg_Watchdog::reset()
{    
    CYG_REPORT_FUNCTION();
 
    cyg_uint16 swsr;
	swsr = 0x556c;
	HAL_WRITE_UINT16(CYGARC_REG_IMM_SWSR, swsr);
	swsr = 0xaa39;
	HAL_WRITE_UINT16(CYGARC_REG_IMM_SWSR, swsr);
 
    CYG_REPORT_RETURN();
}
 
// -------------------------------------------------------------------------
// EOF watchdog_mpc5xx.cxx