// File: watchdog_sw_rst.c
//
// Samsung SMDK6410 SW_RST using watchdog timer support code.
//
#include
#include
#include
#include

// WTCON - control register, bit specifications
#define WTCON_PRESCALE(x) (((x)&0xff)<<8) // bit 15:8, prescale value, 0 <= (x) <= 27
#define WTCON_ENABLE (1<<5) // bit 5, enable watchdog timer
#define WTCON_CLK_DIV16 (0<<3)
#define WTCON_CLK_DIV32 (1<<3)
#define WTCON_CLK_DIV64 (2<<3)
#define WTCON_CLK_DIV128 (3<<3)
#define WTCON_INT_ENABLE (1<<2)
#define WTCON_RESET (1<<0)

// WTCNT - watchdog counter register
#define WTCNT_CNT(x) ((x)&0xffff)

// WTDAT - watchdog reload value register
#define WTDAT_CNT(x) ((x)&0xffff)

// WTCLRINT - watchdog interrupt clear register
#define WTCLRINT_CLEAR (1<<0)

// Watchdog Clock
// PCLK : 66MHz
// PCLK/PRESCALER : 66/66 = 1MHz
// PCLK/PRESCALER/DIVIDER : 1MHz/128 = 7.812 KHz
// MAX Counter = 0xffff = 65535
// Period = 65535/7812 =~ 8.4 sec
#define WD_PRESCALER (66-1)

//------------------------------------------------------------------------------
//
// Function: _OEMSWReset
//
// This is the function to reset S3C6410 using watchdog timer.
//
void _OEMSWReset(void)
{
  volatile S3C6410_WATCHDOG_REG *pWTDogReg = NULL; // VA for Watchdog base
  pWTDogReg = (S3C6410_WATCHDOG_REG *)OALPAtoVA(S3C6410_BASE_REG_PA_WATCHDOG, FALSE);
  if (!pWTDogReg)
  {
  OALMSG (OAL_ERROR, (L'Address of Watch Dog Base Not Defined, WatchDog not enabled!/r/n'));
  }
  else
  {
  pWTDogReg->WTCON = WTCON_PRESCALE(WD_PRESCALER) | WTCON_CLK_DIV128 | WTCON_RESET;
  pWTDogReg->WTDAT = WTDAT_CNT(0x1);
  pWTDogReg->WTCNT = WTCNT_CNT(0x1);
  pWTDogReg->WTCON |= WTCON_ENABLE;
  }
}