text: /*
   * Copyright (c) 2013 - 2014, Freescale Semiconductor, Inc.
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without modification,
   * are permitted provided that the following conditions are met:
   *
   * o Redistributions of source code must retain the above copyright notice, this list
   *   of conditions and the following disclaimer.
   *
   * o 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.
   *
   * o Neither the name of Freescale Semiconductor, Inc. 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 HOLDER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include "fsl_pit_driver.h"
  #include "fsl_clock_manager.h"
  #include "fsl_interrupt_manager.h"
  
  #if FSL_FEATURE_SOC_PIT_COUNT
  
  /*******************************************************************************
   * Variables
   ******************************************************************************/
  
  /* pit source clock variable which will be updated in PIT_DRV_Init */
  uint64_t g_pitSourceClock;
  
  /* pit instance and channel number used by microseconds functions */
  uint8_t g_pitUsInstance;
  uint8_t g_pitUsChannel;
  
  /*******************************************************************************
   * Code
   ******************************************************************************/
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_Init
   * Description   : Initialize PIT module.
   * This function must be called before calling all the other PIT driver functions.
   * This function un-gates the PIT clock and enables the PIT module. The
   * isRunInDebug passed into function will affect all timer channels.
   *
   *END**************************************************************************/
  pit_status_t PIT_DRV_Init(uint32_t instance, bool isRunInDebug)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
  
      /* Un-gate pit clock*/
      CLOCK_SYS_EnablePitClock(instance);
  
      /* Enable PIT module clock*/
      PIT_HAL_Enable(base);
  
      /* Set timer run or stop in debug mode*/
      PIT_HAL_SetTimerRunInDebugCmd(base, isRunInDebug);
  
      /* Finally, update pit source clock frequency.*/
      g_pitSourceClock = CLOCK_SYS_GetPitFreq(instance);
  
      return kStatus_PIT_Success;
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_InitChannel
   * Description   : Initialize PIT channel.
   * This function initialize PIT timers by channel. Pass in timer number and its
   * config structure. Timers do not start counting by default after calling this
   * function. Function PIT_DRV_StartTimer must be called to start timer counting.
   * Call PIT_DRV_SetTimerPeriodByUs to re-set the period.
   *
   *END**************************************************************************/
  void PIT_DRV_InitChannel(uint32_t instance,
                           uint32_t channel,
                           const pit_user_config_t * config)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
  
      /* Set timer period.*/
      PIT_DRV_SetTimerPeriodByUs(instance, channel, config->periodUs);
  
      /* Enable or disable interrupt.*/
      PIT_HAL_SetIntCmd(base, channel, config->isInterruptEnabled);
  
      /* Configure NVIC*/
      if (config->isInterruptEnabled)
      {
          /* Enable PIT interrupt.*/
          INT_SYS_EnableIRQ(g_pitIrqId[channel]);
      }
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_Deinit
   * Description   : Disable PIT module and gate control
   * This function will disable all PIT interrupts and PIT clock. Then gate the
   * PIT clock control. pit_init must be called in order to use PIT again.
   *
   *END**************************************************************************/
  pit_status_t PIT_DRV_Deinit(uint32_t instance)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      uint32_t i;
  
      /* Exit if current instance is gated.*/
      if (!CLOCK_SYS_GetPitGateCmd(instance))
      {
          return kStatus_PIT_Fail;
      }
  
      /* Disable all PIT interrupts. Clear the chain bit if available */
      for (i=0; i < FSL_FEATURE_PIT_TIMER_COUNT; i++)
      {
          PIT_HAL_SetIntCmd(base, i, false);
          INT_SYS_DisableIRQ(g_pitIrqId[i]);
  #if FSL_FEATURE_PIT_HAS_CHAIN_MODE
          PIT_HAL_SetTimerChainCmd(base, i, false);
  #endif
      }
  
      /* Disable PIT module clock*/
      PIT_HAL_Disable(base);
  
      /* Gate PIT clock control*/
      CLOCK_SYS_DisablePitClock(instance);
  
      return kStatus_PIT_Success;
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_StartTimer
   * Description   : Start timer counting.
   * After calling this function, timers load period value, count down to 0 and
   * then load the respective start value again. Each time a timer reaches 0,
   * it will generate a trigger pulse and set the timeout interrupt flag.
   *
   *END**************************************************************************/
  void PIT_DRV_StartTimer(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      PIT_HAL_StartTimer(base, channel);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_StopTimer
   * Description   : Stop timer counting.
   * This function will stop every timer counting. Timers will reload their periods
   * respectively after calling PIT_DRV_StartTimer next time.
   *
   *END**************************************************************************/
  void PIT_DRV_StopTimer(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      PIT_HAL_StopTimer(base, channel);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_SetTimerPeriodByUs
   * Description   : Set timer period in microseconds unit.
   * The period range depends on the frequency of PIT source clock. If required
   * period is out the range, try to use lifetime timer if applicable.
   * This function is only valid for one single channel. If channels are chained together,
   * the period here will make no sense.
   *
   *END**************************************************************************/
  void PIT_DRV_SetTimerPeriodByUs(uint32_t instance, uint32_t channel, uint32_t us)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      /* Calculate the count value, assign it to timer counter register.*/
      uint32_t count = (uint32_t)(us * g_pitSourceClock / 1000000U - 1U);
      PIT_HAL_SetTimerPeriodByCount(base, channel, count);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_GetTimerPeriodByUs
   * Description   : Gets the timer period in microseconds for one single channel.
   *
   *END**************************************************************************/
  uint32_t PIT_DRV_GetTimerPeriodByUs(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      /* Get current timer period by count.*/
      uint64_t currentPeriod = PIT_HAL_GetTimerPeriodByCount(base, channel);
  
      /* Convert count numbers to microseconds unit.*/
      currentPeriod = (currentPeriod + 1U) * 1000000U / g_pitSourceClock;
      return (uint32_t)currentPeriod ;
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_ReadTimerUs
   * Description   : Read current timer value in microseconds unit.
   * This function will return an absolute time stamp in the unit of microseconds.
   * One common use of this function is to measure the running time of part of
   * code. Just call this function at both the beginning and end of code, the time
   * difference between these two time stamp will be the running time (Need to
   * make sure the running time will not exceed the timer period). Also, the time
   * stamp returned is up-counting.
   *
   *END**************************************************************************/
  uint32_t PIT_DRV_ReadTimerUs(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      /* Get current timer count, and reverse it to up-counting.*/
      uint64_t currentTime = (~PIT_HAL_ReadTimerCount(base, channel));
  
      /* Convert count numbers to microseconds unit.*/
      currentTime = (currentTime * 1000000U) / g_pitSourceClock;
      return (uint32_t)currentTime;
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_SetTimerPeriodByCount
   * Description   : Sets the timer period in units of count.
   * Timers begin counting from the value set by this function.
   * The counter period of a running timer can be modified by first stopping
   * the timer, setting a new load value, and  starting the timer again. If
   * timers are not restarted, the new value is loaded after the next trigger
   * event.
   *
   *END**************************************************************************/
  void PIT_DRV_SetTimerPeriodByCount(uint32_t instance, uint32_t channel, uint32_t count)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
  
      PIT_HAL_SetTimerPeriodByCount(base, channel, count);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_GetTimerPeriodByCount
   * Description   : Returns the current timer period in units of count.
   *
   *END**************************************************************************/
  uint32_t PIT_DRV_GetTimerPeriodByCount(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
  
      return PIT_HAL_GetTimerPeriodByCount(base, channel);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_ReadTimerCount
   * Description   : Reads the current timer counting value.
   * This function returns the real-time timer counting value, in a range from 0
   * to a timer period.
   *
   *END**************************************************************************/
  uint32_t PIT_DRV_ReadTimerCount(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
  
      return PIT_HAL_ReadTimerCount(base, channel);
  }
  
  #if FSL_FEATURE_PIT_HAS_LIFETIME_TIMER
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_SetLifetimeTimerPeriodByUs
   * Description   : Set lifetime timer period (Timers must be chained).
   * Timer 1 must be chained with timer 0 before using lifetime timer. The period
   * range is restricted by "period * g_pitSourceClock < max of an uint64_t integer",
   * or it may cause a overflow and is not able to set correct period.
   *
   *END**************************************************************************/
  void PIT_DRV_SetLifetimeTimerPeriodByUs(uint32_t instance, uint64_t us)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      uint64_t lifeTimeCount;
  
      /* Calculate the counter value.*/
      lifeTimeCount = us * g_pitSourceClock / 1000000U - 1U;
  
      /* Assign to timers.*/
      PIT_HAL_SetTimerPeriodByCount(base, 0U, (uint32_t)lifeTimeCount);
      PIT_HAL_SetTimerPeriodByCount(base, 1U, (uint32_t)(lifeTimeCount >> 32U));
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_ReadLifetimeTimerUs
   * Description   : Read current lifetime value in microseconds unit.
   * Return an absolute time stamp in the unit of microseconds. The time stamp
   * value will not exceed the timer period. Also, the timer is up-counting.
   *
   *END**************************************************************************/
  uint64_t PIT_DRV_ReadLifetimeTimerUs(uint32_t instance)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
      /* Get current lifetime timer count, and reverse it to up-counting.*/
      uint64_t currentTime = (~PIT_HAL_ReadLifetimeTimerCount(base));
  
      /* Convert count numbers to microseconds unit.*/
      /* Note: using currentTime * 1000 rather than 1000000 to avoid short time overflow. */
      return currentTime = (currentTime * 1000U) / (g_pitSourceClock / 1000U);
  }
  #endif /* FSL_FEATURE_PIT_HAS_LIFETIME_TIMER*/
  
  #if FSL_FEATURE_PIT_HAS_CHAIN_MODE
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_InitUs
   * Description   : Initializes two PIT channels to serve as a microseconds unit.
   * This function is in parallel with PIT_DRV_InitChannel, they will overwrite
   * each other. PIT_DRV_Init must be called before calling this function.
   * The microseconds unit will use two chained channels to simulate a lifetime
   * timer, the channel number passed in and the "channel -1" channel will be used.
   * Note:
   * 1. These two channels will be occupied and could not be used with other purposes.
   * 2. The channel number passed in must be greater than 0.
  
   *END**************************************************************************/
  void PIT_DRV_InitUs(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
      assert(channel > 0U);
  
      PIT_Type * base = g_pitBase[instance];
      g_pitUsInstance = instance;
      g_pitUsChannel = channel;
  
      PIT_HAL_SetTimerChainCmd(base, channel, true);
      PIT_HAL_SetTimerPeriodByCount(base, channel, 0xFFFFFFFFU);
      PIT_HAL_SetTimerPeriodByCount(base, channel - 1U, 0xFFFFFFFFU);
  
      PIT_HAL_StartTimer(base, channel);
      PIT_HAL_StartTimer(base, channel - 1U);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_GetUs
   * Description   : Get an absolute time stamp.
   * This function is useful to get elapsed time through calling this function in
   * time A, and then call it in time B. The elapsed time could be get by B-A, the
   * result may have 3-5 microseconds error depends on system clock frequency.
   *
   *END**************************************************************************/
  uint32_t PIT_DRV_GetUs(void)
  {
      PIT_Type * base = g_pitBase[g_pitUsInstance];
      /* Get current timer count, and reverse it to up-counting.*/
      uint64_t currentTime = ~(((uint64_t)PIT_HAL_ReadTimerCount(base, g_pitUsChannel) << 32U) +
                             PIT_HAL_ReadTimerCount(base, g_pitUsChannel - 1U));
  
      /* Convert count numbers to microseconds unit.*/
      return currentTime = (currentTime * 1000U) / (g_pitSourceClock / 1000U);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_DelayUs
   * Description   : Delay specific microseconds.
   * The delay will have a 3-5 microseconds error depends on system clock frequency.
   *
   *END**************************************************************************/
  void PIT_DRV_DelayUs(uint32_t us)
  {
      PIT_Type * base = g_pitBase[g_pitUsInstance];
  
      uint64_t x = us * g_pitSourceClock / 1000000;
      uint64_t timeToBe = ((uint64_t)PIT_HAL_ReadTimerCount(base, g_pitUsChannel) << 32U) +
                             PIT_HAL_ReadTimerCount(base, g_pitUsChannel - 1U) - x;
  
      while (((uint64_t)PIT_HAL_ReadTimerCount(base, g_pitUsChannel) << 32U) +
                        PIT_HAL_ReadTimerCount(base, g_pitUsChannel - 1U)
                        >= timeToBe)
      {}
  }
  
  #endif /* FSL_FEATURE_PIT_HAS_CHAIN_MODE */
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_ClearIntFlag
   * Description   : Clears the timer interrupt flag.
   *
   *END**************************************************************************/
  void PIT_DRV_ClearIntFlag(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
  
      PIT_HAL_ClearIntFlag(base, channel);
  }
  
  /*FUNCTION**********************************************************************
   *
   * Function Name : PIT_DRV_IsIntPending
   * Description   : Reads the current timer timeout flag.
   *
   *END**************************************************************************/
  bool PIT_DRV_IsIntPending(uint32_t instance, uint32_t channel)
  {
      assert(instance < PIT_INSTANCE_COUNT);
  
      PIT_Type * base = g_pitBase[instance];
  
      return PIT_HAL_IsIntPending(base, channel);
  }
  
  #endif /* FSL_FEATURE_SOC_PIT_COUNT */
  /*******************************************************************************
   * EOF
   ******************************************************************************/
  
  