nuttx/sched/wdog/wd_gettime.c

/********************************************************************************
 * sched/wdog/wd_gettime.c
 *
 *   Copyright (C) 2007, 2009, 2014-2015 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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 ********************************************************************************/

/********************************************************************************
 * Included Files
 ********************************************************************************/

#include <nuttx/config.h>

#include <nuttx/wdog.h>
#include <arch/irq.h>

#include "wdog/wdog.h"

/********************************************************************************
 * Pre-processor Definitions
 ********************************************************************************/

/********************************************************************************
 * Private Types
 ********************************************************************************/

/********************************************************************************
 * Global Variables
 ********************************************************************************/

/********************************************************************************
 * Private Variables
 ********************************************************************************/

/********************************************************************************
 * Private Functions
 ********************************************************************************/

/********************************************************************************
 * Public Functions
 ********************************************************************************/

/********************************************************************************
 * Name: wd_gettime
 *
 * Description:
 *   This function returns the time remaining before the specified watchdog
 *   expires.
 *
 * Parameters:
 *   wdog = watchdog ID
 *
 * Return Value:
 *   The time in system ticks remaining until the watchdog time expires.  Zero
 *   means either that wdog is not valid or that the wdog has already expired.
 *
 * Assumptions:
 *
 ********************************************************************************/

int wd_gettime(WDOG_ID wdog)
{
  irqstate_t flags;

  /* Verify the wdog */

  flags = irqsave();
  if (wdog && WDOG_ISACTIVE(wdog))
    {
      /* Traverse the watchdog list accumulating lag times until we find the wdog
       * that we are looking for
       */

      FAR struct wdog_s *curr;
      int delay = 0;

      for (curr = (FAR struct wdog_s *)g_wdactivelist.head; curr; curr = curr->next)
        {
          delay += curr->lag;
          if (curr == wdog)
            {
              irqrestore(flags);
              return delay;
            }
        }
    }

  irqrestore(flags);
  return 0;
}