source: rtems/c/src/lib/libbsp/sparc/leon3/timer/watchdog.c @ 4a7d1026

/*  GPTIMER Watchdog timer routines. On some systems the first GPTIMER
 *  core's last Timer instance underflow signal is connected to system
 *  reset.
 *
 *  COPYRIGHT (c) 2012.
 *  Cobham Gaisler AB.
 *
 *  The license and distribution terms for this file may be
 *  found in the file LICENSE in this distribution or at
 *  http://www.rtems.org/license/LICENSE.
 */

#include <bsp.h>
#include <bsp/watchdog.h>
#include <grlib.h>

extern volatile struct gptimer_regs *LEON3_Timer_Regs;

struct gptimer_watchdog_priv {
  struct gptimer_regs *regs;
  struct gptimer_timer_regs *timer;
  int timerno;
};

struct gptimer_watchdog_priv bsp_watchdogs[1];
int bsp_watchdog_count = 0;

int bsp_watchdog_init(void)
{
  int timercnt;

  if (!LEON3_Timer_Regs)
    return 0;

  /* Get Watchdogs in system, this is implemented for one GPTIMER core
   * only.
   *
   * First watchdog is a special case, we can get the first timer core by
   * looking at LEON3_Timer_Regs, the watchdog within a timer core is
   * always the last timer. Unfortunately we can not know it the watchdog
   * functionality is available or not, we assume that it is if we
   * reached this function.
   */
  bsp_watchdogs[0].regs = (struct gptimer_regs *)LEON3_Timer_Regs;

  /* Find Timer that has watchdog functionality */
  timercnt = bsp_watchdogs[0].regs->cfg & 0x7;
  if (timercnt < 2) /* First timer system clock timer */
    return 0;

  bsp_watchdogs[0].timerno = timercnt - 1;
  bsp_watchdogs[0].timer = &bsp_watchdogs[0].regs->timer[bsp_watchdogs[0].timerno];

  bsp_watchdog_count = 1;
  return bsp_watchdog_count;
}

void bsp_watchdog_reload(int watchdog, unsigned int reload_value)
{
  if (bsp_watchdog_count == 0)
    bsp_watchdog_init();

  if (bsp_watchdog_count <= watchdog)
    return;

  /* Kick watchdog, and clear interrupt pending bit */
  bsp_watchdogs[watchdog].timer->reload = reload_value;
  bsp_watchdogs[watchdog].timer->ctrl =
    (GPTIMER_TIMER_CTRL_LD | GPTIMER_TIMER_CTRL_EN) |
    (bsp_watchdogs[watchdog].timer->ctrl & ~(1<<4));
}

void bsp_watchdog_stop(int watchdog)
{
  if (bsp_watchdog_count == 0)
    bsp_watchdog_init();

  if (bsp_watchdog_count <= watchdog)
    return;

  /* Stop watchdog timer */
  bsp_watchdogs[watchdog].timer->ctrl = 0;
}

/* Use watchdog timer to reset system */
void bsp_watchdog_system_reset(void)
{
  sparc_disable_interrupts();
  bsp_watchdog_reload(0, 1);
}