nuttx/net/utils/net_dsec2tick.c

/****************************************************************************
 * net/utils/net_dsec2tick.c
 *
 *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
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 *
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 *    distribution.
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 *    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
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 ****************************************************************************/

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

#include <nuttx/config.h>
#include <nuttx/clock.h>

#include "utils/utils.h"

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

/****************************************************************************
 * Name: net_dsec2tick
 *
 * Description:
 *   Convert a decisecond value to a system clock ticks.  Used by IGMP logic.
 *
 * Input Parameters:
 *   dsec The decisecond value to convert
 *
 * Returned Value:
 *   The decisecond value expressed as system clock ticks
 *
 ****************************************************************************/

unsigned int net_dsec2tick(int dsec)
{
  /* Convert the deci-second comparison value to clock ticks.  The CLK_TCK
   * value is the number of clock ticks per second; decisecs argument is the
   * maximum delay in 100's of milliseconds.  CLK_TCK/10 is then the number
   * of clock ticks in 100 milliseconds.
   */

  return CLK_TCK * dsec / 10;
}