FreeRTOS/Demo/IA32_flat_GCC_Galileo_Gen_2/Support_Files/HPET.c

/*--------------------------------------------------------------------
 Copyright(c) 2015 Intel Corporation. All rights reserved.

 Redistribution and use in source and binary forms, with or without
 modification, are permitted provided that the following conditions
 are met:

 * Redistributions of source code must retain the above copyright
 notice, this list of conditions and the following disclaimer.
 * 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.
 * Neither the name of Intel Corporation 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, 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.
 --------------------------------------------------------------------*/

/*-----------------------------------------------------------------------
 * Any required includes
 *------------------------------------------------------------------------
 */
#include "FreeRTOS.h"
#include "task.h"
#include "portmacro.h"
#include "galileo_support.h"

/*-----------------------------------------------------------------------
 * Function prototypes
 *------------------------------------------------------------------------
 */
#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	static void vHPETIRQHandler0(void);
#endif
#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	void vHPETIRQHandler1(void);
#endif
#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	static void vHPETIRQHandler2(void);
#endif

/*-----------------------------------------------------------------------
 * Always inline HPET ISR related routines (even with no optimization),
 * This is done for speed reasons to keep the ISR as fast as possible.
 *------------------------------------------------------------------------
 */
#if (hpetHPET_TIMER_IN_USE)
	static inline void vSetTVS( uint32_t ) __attribute__((always_inline));
	static inline void vSetHPETComparator( uint32_t, uint64_t ) __attribute__((always_inline));
	static inline uint64_t ullReadHPETCounters( void ) __attribute__((always_inline));
	static inline void vHPET_ISR (uint32_t) __attribute__((always_inline));
#endif

/*-----------------------------------------------------------------------
 * Global variables
 *------------------------------------------------------------------------
 */
volatile uint32_t hpet_general_status;
volatile uint32_t ulHPETTimerNumber [3] = {0, 1, 2};
volatile uint32_t ulHPETTotalInterrupts [3] = {0, 0, 0};
volatile uint32_t ulHPETElapsedSeconds [3] = {0, 0, 0};
volatile uint32_t ulHPETInterruptFrequency [3] = {0, 0, 0};
volatile uint32_t ulHPETTicksToInterrupt [3] = {0, 0, 0};
struct hpet_info PrintInfo[3] =
{
	{0, 0, 0, 0, 0, 0, 0},
	{1, 0, 0, 0, 0, 0, 0},
	{2, 0, 0, 0, 0, 0, 0},
};

/*-----------------------------------------------------------------------
 * Static variables
 *------------------------------------------------------------------------
 */
#if (hpetHPET_TIMER_IN_USE)
	static uint32_t hpet_general_id;
	static uint32_t hpet_counter_tick_period;
#endif

/*-----------------------------------------------------------------------
 * General HPET functions
 *------------------------------------------------------------------------
 */
#if (hpetHPET_TIMER_IN_USE)
static void vClearHPETCounters( void )
{
	hpetHPET_MAIN_CTR_LOW = 0UL;
	hpetHPET_MAIN_CTR_HIGH = 0UL;
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
void vClearHPETElapsedSeconds( void )
{
	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		ulHPETElapsedSeconds[0] = 0UL;
		ulHPETTotalInterrupts [0] = 0UL;
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		ulHPETElapsedSeconds[1] = 0UL;
		ulHPETTotalInterrupts [1] = 0UL;
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	{
		ulHPETElapsedSeconds[2] = 0UL;
		ulHPETTotalInterrupts [2] = 0UL;
	}
	#endif
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static inline void vSetTVS( uint32_t TimerNumber )
{
	volatile uint32_t hpet_cfg = 0UL;
	const uint32_t uiTVS = (1UL << 6UL);

	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		if (TimerNumber == 0)
		{
			hpet_cfg = hpetHPET_TMR0_CONFIG_LOW | uiTVS;
			hpetHPET_TMR0_CONFIG_LOW = hpet_cfg;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		if (TimerNumber == 1)
		{
			hpet_cfg = hpetHPET_TMR1_CONFIG_LOW | uiTVS;
			hpetHPET_TMR1_CONFIG_LOW = hpet_cfg;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	{
		if (TimerNumber == 2)
		{
			hpet_cfg = hpetHPET_TMR2_CONFIG_LOW | uiTVS;
			hpetHPET_TMR2_CONFIG_LOW = hpet_cfg;
		}
	}
	#endif
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static inline void vSetHPETComparator( uint32_t TimerNumber, uint64_t Value )
{
	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		if (TimerNumber == 0)
		{
			vSetTVS(TimerNumber);
			hpetHPET_TMR0_COMPARATOR_LOW = (uint32_t)(Value & 0xFFFFFFFFULL);
			vSetTVS(TimerNumber);
			hpetHPET_TMR0_COMPARATOR_HIGH = (uint32_t)((Value >> 32UL) & 0xFFFFFFFFULL);
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		if (TimerNumber == 1)
		{
			vSetTVS(TimerNumber);
			hpetHPET_TMR1_COMPARATOR_LOW = (uint32_t)(Value & 0xFFFFFFFFULL);
			vSetTVS(TimerNumber);
			hpetHPET_TMR1_COMPARATOR_HIGH = (uint32_t)((Value >> 32UL) & 0xFFFFFFFFULL);
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	{
		if (TimerNumber == 2)
		{
			vSetTVS(TimerNumber);
			hpetHPET_TMR2_COMPARATOR_LOW = (uint32_t)(Value & 0xFFFFFFFFULL);
			vSetTVS(TimerNumber);
			hpetHPET_TMR2_COMPARATOR_HIGH = (uint32_t)((Value >> 32UL) & 0xFFFFFFFFULL);
		}
	}
	#endif
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static inline uint64_t ullReadHPETCounters( void )
{
	volatile uint64_t Counters = (uint64_t)
	(((uint64_t)hpetHPET_MAIN_CTR_HIGH << 32UL) |
	(uint64_t)hpetHPET_MAIN_CTR_LOW);
	return Counters;
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static void vStopHPETTimer( uint32_t ClearCounters )
{
	uint32_t hpet_cfg = 0UL;

	/* Clear configuration enable bit */
	hpet_cfg = hpetHPET_GENERAL_CONFIGURATION;
	hpet_cfg &= ~hpetHPET_CFG_ENABLE;
	hpetHPET_GENERAL_CONFIGURATION = hpet_cfg;

	/* Clear counters */
	if (ClearCounters)
		vClearHPETCounters();
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static void vStartHPETTimer( void )
{
	uint32_t hpet_cfg = 0UL;
	uint8_t  LegacyMode = TRUE; // See table in doc # 329676 page 867

	hpet_general_status = hpetHPET_GENERAL_STATUS;

	if (hpet_general_status != 0x0UL)
		hpetHPET_GENERAL_STATUS = hpet_general_status;

	hpet_cfg = hpetHPET_GENERAL_CONFIGURATION;
	hpet_cfg |= hpetHPET_CFG_ENABLE;

	if(LegacyMode != FALSE)
		hpet_cfg |= hpetHPET_CFG_LEGACY;
	else
		hpet_cfg &= ~hpetHPET_CFG_LEGACY;

	hpetHPET_GENERAL_CONFIGURATION = hpet_cfg;
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static void vConfigureHPETTimer( uint32_t TimerNumber, uint32_t PeriodicMode  )
{
	uint32_t hpet_cfg = 0UL;				// Configuration data
	uint8_t  IRQNumber = 0;					// Hardware ISR number
	uint8_t  Triggering = 0;				// Level or Edge sensitive

	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		if (TimerNumber == 0)
		{
			IRQNumber = TIMER0_IRQ;
			Triggering = TIMER0_TRIGGERING;
			hpet_cfg = hpetHPET_TMR0_CONFIG_LOW;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		if (TimerNumber == 1)
		{
			IRQNumber = TIMER1_IRQ;
			Triggering = TIMER1_TRIGGERING;
			hpet_cfg = hpetHPET_TMR1_CONFIG_LOW;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	{
		if (TimerNumber == 2)
		{
			IRQNumber = TIMER2_IRQ;
			Triggering = TIMER2_TRIGGERING;
			hpet_cfg = hpetHPET_TMR2_CONFIG_LOW;
		}
	}
	#endif

	/* Modify configuration */
	if (PeriodicMode != FALSE)
	{
		hpet_cfg |= hpetHPET_TN_ENABLE | hpetHPET_TN_PERIODIC | hpetHPET_TN_SETVAL |
		hpetHPET_TN_32BIT | ((IRQNumber & 0x1F) << 9UL);
	}
	else
	{
		hpet_cfg |= hpetHPET_TN_ENABLE | hpetHPET_TN_SETVAL |
		hpetHPET_TN_32BIT | ((IRQNumber & 0x1F) << 9UL);
	}

	/* Setup triggering bit */
	if (Triggering != hpetHPET_INT_EDGE)
		hpet_cfg |= (1UL << 1UL);
	else
		hpet_cfg &= ~(1UL << 1UL);

	/* write-out configuration */
	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
		if (TimerNumber == 0)
		{
			hpetHPET_TMR0_CONFIG_LOW = hpet_cfg;
		}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
		if (TimerNumber == 1)
		{
			hpetHPET_TMR1_CONFIG_LOW = hpet_cfg;
		}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
		if (TimerNumber == 2)
		{
			hpetHPET_TMR2_CONFIG_LOW = hpet_cfg;
		}
	#endif
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static void vGetHPETCapabilitiesAndStatus( void )
{
	/* Get HPET capabilities and ID */
	hpet_general_id = hpetHPET_GENERAL_ID;

	/* Invalid vendor ID - Should be Intel (0x8086") */
	if ((hpet_general_id >> 16) != 0x8086UL)
	{
		configASSERT( 0 );
	}

	/* Get number of ns/tick - default is 69.841279 */
	hpet_counter_tick_period = hpetHPET_COUNTER_TICK_PERIOD;

	/* General status of HPET -  bit 0 = T0, bit 1 = T1 and bit 2 = T2.
	 * In level triggered mode 1 means interrupt is active */
	hpet_general_status = hpetHPET_GENERAL_STATUS;
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static void vCheckHPETIRQCapabilities( uint32_t TimerNumber)
{
	uint32_t hpet_cfg_h = 0UL;
	uint32_t hpet_cfg_l = 0UL;
	uint32_t IRQNumber = 0UL;
	uint32_t Triggering = hpetHPET_INT_EDGE;

	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		if (TimerNumber == 0)
		{
			IRQNumber = TIMER0_IRQ;
			Triggering = TIMER0_TRIGGERING;
			hpet_cfg_h = hpetHPET_TMR0_CONFIG_HIGH;
			hpet_cfg_l = hpetHPET_TMR0_CONFIG_LOW;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		if (TimerNumber == 1)
		{
			IRQNumber = TIMER1_IRQ;
			Triggering = TIMER1_TRIGGERING;
			hpet_cfg_h = hpetHPET_TMR1_CONFIG_HIGH;
			hpet_cfg_l = hpetHPET_TMR1_CONFIG_LOW;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	{
		if (TimerNumber == 2)
		{
			IRQNumber = TIMER2_IRQ;
			Triggering = TIMER2_TRIGGERING;
			hpet_cfg_h = hpetHPET_TMR2_CONFIG_HIGH;
			hpet_cfg_l = hpetHPET_TMR2_CONFIG_LOW;
		}
	}
	#endif

	/* Setup configuration register */
	hpet_cfg_l |= hpetHPET_TN_ENABLE | hpetHPET_TN_PERIODIC |
	hpetHPET_TN_32BIT | ((IRQNumber & 0x1F) << 9UL);

	/* Setup triggering bit */
	if (Triggering != hpetHPET_INT_EDGE)
		hpet_cfg_l |= (1UL << 1UL);
	else
		hpet_cfg_l &= ~(1UL << 1UL);

	/* Write then read back configuration */
	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		if (TimerNumber == 0)
		{
			hpetHPET_TMR0_CONFIG_HIGH = hpet_cfg_h;
			hpetHPET_TMR0_CONFIG_LOW = hpet_cfg_l;
			hpet_cfg_l = hpetHPET_TMR0_CONFIG_LOW;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		if (TimerNumber == 1)
		{
			hpetHPET_TMR1_CONFIG_HIGH = hpet_cfg_h;
			hpetHPET_TMR1_CONFIG_LOW = hpet_cfg_l;
			hpet_cfg_l = hpetHPET_TMR1_CONFIG_LOW;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	{
		if (TimerNumber == 2)
		{
			hpetHPET_TMR2_CONFIG_HIGH = hpet_cfg_h;
			hpetHPET_TMR2_CONFIG_LOW = hpet_cfg_l;
			hpet_cfg_l = hpetHPET_TMR2_CONFIG_LOW;
		}
	}
	#endif
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static uint32_t uiCalibrateHPETTimer(uint32_t TimerNumber, uint32_t Calibrate)
{
	uint32_t ticks_per_ms = 15422; // 1e-3/64.84127e-9 (denominator is hpet_counter_tick_period)
	if (Calibrate)
	{
		uint32_t uiRunningTotal = 0UL;
		uint32_t i = 0UL;
		for (i = 0; i < 5; i++)
			uiRunningTotal += uiCalibrateTimer(TimerNumber, hpetHPETIMER);
		ticks_per_ms = (uiRunningTotal / 5);
	}
	return ticks_per_ms;
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static void vSetupIOApic( uint32_t TimerNumber )
{
	uint8_t DeliveryMode = 1; 					// 0 means fixed (use ISR Vector)
	uint8_t DestinationMode = 0;  				// Used by local APIC for MSI
	uint8_t IRQPolarity = 1;					// 0 means active high, 1 = active low
	uint8_t InterruptMask = 0;					// 0 means allow interrupts
	uint8_t Triggering = hpetHPET_INT_EDGE;		// Level or Edge sensitive
	uint8_t IRQNumber = 0;						// Hardware IRQ number
	uint8_t ISRVector = 0;						// Desired ISR vector

	/* Select polarity and triggering */
	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		if (TimerNumber == 0)
		{
			IRQNumber = TIMER0_IRQ;
			ISRVector = hpetHPET_TIMER0_ISR_VECTOR;
			IRQPolarity = TIMER0_POLARITY;
			Triggering = TIMER0_TRIGGERING;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		if (TimerNumber == 1)
		{
			IRQNumber = TIMER1_IRQ;
			ISRVector = hpetHPET_TIMER1_ISR_VECTOR;
			IRQPolarity = TIMER1_POLARITY;
			Triggering = TIMER1_TRIGGERING;
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	{
		if (TimerNumber == 2)
		{
			IRQNumber = TIMER2_IRQ;
			ISRVector = hpetHPET_TIMER2_ISR_VECTOR;
			IRQPolarity = TIMER2_POLARITY;
			Triggering = TIMER2_TRIGGERING;
		}
	}
	#endif

	/* Data to write to RTE register Lower DW */
	uint32_t ConfigDataLDW = (uint32_t)(ISRVector | ((DeliveryMode & 0x07) << 8UL));

	/* Set or clear bits in configuration data */
	if (DestinationMode == 0)
		ConfigDataLDW &= ~(1UL << 11UL);
	else
		ConfigDataLDW |= (1UL << 11UL);

	if (IRQPolarity == 0)
		ConfigDataLDW &= ~(1UL << 13UL);
	else
		ConfigDataLDW |= (1UL << 13UL);

	if (Triggering != FALSE)
		ConfigDataLDW |= (1UL << 15UL);
	else
		ConfigDataLDW &= ~(1UL << 15UL);

	if (InterruptMask == 0)
		ConfigDataLDW &= ~(1UL << 16UL);
	else
		ConfigDataLDW |= (1UL << 16UL);

	/* Data to write to RTE register Upper DW */
	uint32_t LocalAPIC_DID = ((portAPIC_ID_REGISTER & 0xFF000000UL) >> 24UL); 	// get local APIC DID
	uint32_t LocalAPIC_EDID = ((portAPIC_ID_REGISTER & 0x00FF0000UL) >> 16UL);	// get local APIC Extended DID
	uint32_t ConfigDataUDW = (uint32_t)(((LocalAPIC_DID << 24UL) & 0xFF000000UL) |
	((LocalAPIC_EDID << 16UL) & 0x00FF0000UL));

	/* Setup IDX and WDW register to write RTE data */
	hpetIO_APIC_IDX = hpetIO_APIC_RTE_OFFSET + ((2 * IRQNumber) + 1);
	hpetIO_APIC_WDW = ConfigDataUDW;
	hpetIO_APIC_IDX = hpetIO_APIC_RTE_OFFSET + ((2 * IRQNumber) + 0);
	hpetIO_APIC_WDW = ConfigDataLDW;
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
static void vInitilizeHPETInterrupt( uint32_t TimerNumber )
{
	/* NOTE: In non-legacy mode interrupts are sent as MSI messages to LAPIC */

	uint32_t ticks_per_ms = 0UL;			// Get # ticks per ms
	uint32_t InterruptFrequency = 0UL;		// Get times per second to interrupt

	/* Stop the timers and reset the main counter */
	vStopHPETTimer(true);

	/* Initialise hardware */
	vSetupIOApic(TimerNumber);

	/* Register ISRs.  Purely for demonstration purposes, timer 0 and timer 2
	use the central interrupt entry code, so are installed using
	xPortRegisterCInterruptHandler(), while timer 1 uses its own interrupt
	entry code, so is installed using xPortInstallInterruptHandler().  For
	convenience the entry code for timer 1 is implemented at the bottom of
	RegTest.S.See
	http://www.freertos.org/RTOS_Intel_Quark_Galileo_GCC.html#interrupts for
	more information. */
	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	{
		if (TimerNumber == 0)
		{
			InterruptFrequency = hpetHPET_TIMER0_INTERRUPT_RATE;
			xPortRegisterCInterruptHandler( vHPETIRQHandler0, hpetHPET_TIMER0_ISR_VECTOR );
		}
	}
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	{
		if (TimerNumber == 1)
		{
		extern void vApplicationHPETTimer1Wrapper( void );

			InterruptFrequency = hpetHPET_TIMER1_INTERRUPT_RATE;
			xPortInstallInterruptHandler( vApplicationHPETTimer1Wrapper, hpetHPET_TIMER1_ISR_VECTOR );
		}
	}
	#endif
	#if ( hpetUSE_HPET_TIMER_NUMBER_2 == 1)
	{
		if (TimerNumber == 2)
		{
			configASSERT(TimerNumber == 2)
			InterruptFrequency = hpetHPET_TIMER2_INTERRUPT_RATE;
			xPortRegisterCInterruptHandler( vHPETIRQHandler2, hpetHPET_TIMER2_ISR_VECTOR );
		}
	}
	#endif

	/* Get calibrated ticks per millisecond before initialization. */
	ticks_per_ms = uiCalibrateHPETTimer(TimerNumber, TRUE);

	/* Check IRQ compatibility - will assert here if there is a problem. */
	vCheckHPETIRQCapabilities(TimerNumber);

	/* Get HPET capabilities and ID and status */
	vGetHPETCapabilitiesAndStatus();

	/* Sanity check for frequency */
	if ( InterruptFrequency < 1 )
		InterruptFrequency = 20;	// default is 50 ms interrupt rate

	/* Save interrupt frequency */
	ulHPETInterruptFrequency[TimerNumber] = InterruptFrequency;

	/* Calculate required number of ticks */
	uint32_t ticks = ( ticks_per_ms * 1000UL ) / ulHPETInterruptFrequency[TimerNumber];

	/* Save the number of ticks to interrupt */
	ulHPETTicksToInterrupt[TimerNumber] = ticks;

	/* Make sure counters are zeroed */
	vClearHPETCounters();

	/* Write out comparator value */
	vSetHPETComparator(TimerNumber, ticks);

	/* Set target timer non-periodic mode with first interrupt at tick */
	vConfigureHPETTimer(TimerNumber, FALSE);

	/* Start the timer */
	vStartHPETTimer();
}
#endif
/*-----------------------------------------------------------*/

#if (hpetHPET_TIMER_IN_USE)
void vInitializeAllHPETInterrupts( void )
{
	#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
		vInitilizeHPETInterrupt( 0 );
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
		vInitilizeHPETInterrupt( 1 );
	#endif
	#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
		vInitilizeHPETInterrupt( 2 );
	#endif
}
#endif
/*-----------------------------------------------------------*/

uint32_t uiCalibrateTimer( uint32_t TimerNumber, uint32_t TimerType)
{
	/*---------------------------------------------------------------------*/
	/* NOTE: If TimerType = LVTIMER then TimerNumber is ignored (PIT # 2   */
	/* is always used)                                                     */
	/*---------------------------------------------------------------------*/
	/*---------------------------------------------------------------------*/
	/* PIT (programmable interval timer) mode register Bit definitions     */
	/*----------------------------------------------------------------------
	 Mode register is at address 0x43:
	 Bits         Usage
	 6 and 7      Select channel :
	                 0 0 = Channel 0
	                 0 1 = Channel 1
	                 1 0 = Channel 2
	                 1 1 = Read-back command (8254 only)
	 4 and 5      Access mode :
	                 0 0 = Latch count value command
	                 0 1 = Access mode: lobyte only
	                 1 0 = Access mode: hibyte only
	                 1 1 = Access mode: lobyte/hibyte
	 1 to 3       Operating mode :
	                 0 0 0 = Mode 0 (interrupt on terminal count)
	                 0 0 1 = Mode 1 (hardware re-triggerable one-shot)
	                 0 1 0 = Mode 2 (rate generator)
	                 0 1 1 = Mode 3 (square wave generator)
	                 1 0 0 = Mode 4 (software triggered strobe)
	                 1 0 1 = Mode 5 (hardware triggered strobe)
	                 1 1 0 = Mode 2 (rate generator, same as 010b)
	                 1 1 1 = Mode 3 (square wave generator, same as 011b)
	 0            BCD/Binary mode: 0 = 16-bit binary, 1 = four-digit BCD
	----------------------------------------------------------------------*/

	/* Used to calculate LVT ticks */
	const uint32_t uiLargeNumber = 0x7fffffffUL;

	/* Default return value */
	uint32_t ticks = 0;

	/* Check timer type */
	switch (TimerType)
	{
		case hpetLVTIMER:
		case hpetHPETIMER:
			break;
		default:
			return ticks;
			break;
	}

	/* Set timeout counter to a very large value */
	uint64_t timeout_counter = (uint64_t) (uiLargeNumber * 4);

	/* Set PIT Ch2 to one-shot mode */
	uint32_t gate_register = ((inw(GATE_CONTROL) & 0xfd) | 0x01);
	outw(GATE_CONTROL, gate_register);
	outw(MODE_REGISTER, ONESHOT_MODE);

	/* Set counter for 10 ms - 1193180/100 Hz ~ 11932 */
	uint16_t pit_counter = 11932;
	outb(CHANNEL2_DATA, (char) (pit_counter & 0xff));
	outb(CHANNEL2_DATA, (char) ((pit_counter >> 8) & 0xff));

	/* Start target timer  */
	if (TimerType == hpetLVTIMER)
	{
		portAPIC_LVT_TIMER = portAPIC_TIMER_INT_VECTOR;
		portAPIC_TMRDIV = portAPIC_DIV_16;
	}
	else if (TimerType == hpetHPETIMER)
	{
		#if (hpetHPET_TIMER_IN_USE)
			// Initialize HPE timer
			vStopHPETTimer(TRUE);
			/* Write out comparator value - we don't want it to interrupt */
			vSetHPETComparator(TimerNumber, 0xFFFFFFFFUL);
			// Configure HPE timer for non-periodic mode
			vConfigureHPETTimer(TimerNumber, FALSE);
		#else
			( void ) TimerNumber;
		#endif
	}

	/* Reset PIT one-shot counter */
	gate_register = (inw(GATE_CONTROL) & 0xfe);
	outw(GATE_CONTROL, gate_register);
	gate_register |= 0x01;
	outw(GATE_CONTROL, gate_register);

	/* Setup target timer initial counts */
	if (TimerType == hpetLVTIMER)
	{
		portAPIC_TIMER_INITIAL_COUNT = uiLargeNumber;
	}
	else if (TimerType == hpetHPETIMER)
	{
		#if (hpetHPET_TIMER_IN_USE)
			vStartHPETTimer();
		#endif
	}

	/* Wait for PIT counter to expire */
	for (;;)
	{
		gate_register = inw(GATE_CONTROL);
		if ((gate_register & 0x20) || (--timeout_counter == 0))
		{
			/* Stop target timer and exit loop */
			if (TimerType == hpetLVTIMER)
			{
				portAPIC_LVT_TIMER = portAPIC_DISABLE;
				break;
			}
			else if (TimerType == hpetHPETIMER)
			{
				#if (hpetHPET_TIMER_IN_USE)
					vStopHPETTimer(FALSE);
					break;
				#endif
			}
		}
	}

	/* Check for timeout */
	if (timeout_counter != 0)
	{
		if (TimerType == hpetLVTIMER)
		{
			/* Counter started at a large number so subtract counts */
			ticks = (uiLargeNumber - portAPIC_TIMER_CURRENT_COUNT);
			/* adjust ticks for 1 ms and divider ratio */
			ticks = ((((ticks << 4UL) * 100) / 1000) >> 4UL);
		}
		else if (TimerType == hpetHPETIMER)
		{
			#if (hpetHPET_TIMER_IN_USE)
				/* Read timer counter - we only need the low counter */
				ticks = (uint32_t)(ullReadHPETCounters() & 0xFFFFFFFFULL);
				/* Clear timer counter */
				vClearHPETCounters();
				/* Return 1 ms tick counts. Timed for 10 ms so just divide by 10 */
				ticks /= 10;
			#endif
		}
	}

	/* Return adjusted counts for a 1 ms interrupt rate.
	 * Should be approximately 25000 for LV Timer.
	 * Should be approximately 15000 for HPE Timers */
	return ticks;
}

/*-----------------------------------------------------------------------
 * Interrupt service functions
 *------------------------------------------------------------------------
 */
#if (hpetHPET_TIMER_IN_USE)
static inline void vHPET_ISR( uint32_t TimerNumber )
{
	/*-----------------------------------------------------------------*/
	/* Notes: In edge triggered mode, no need to clear int status bits.*/
	/*                                                                 */
	/* In non-periodic mode, comparator is added to current counts,    */
	/* do not clear main counters.                                     */
	/*-----------------------------------------------------------------*/
	__asm volatile( "cli" );

	/* Bump HPE timer interrupt count - available in a global variable */
	ulHPETTotalInterrupts[TimerNumber] += 1UL;

	/* Bump HPE timer elapsed seconds count - available in a global variable */
	if ((ulHPETTotalInterrupts[TimerNumber] %
		(ulHPETInterruptFrequency[TimerNumber] + 0UL)) == 0UL)
		ulHPETElapsedSeconds[TimerNumber] += 1UL;

	/* Reload comparators - a must do in non-periodic mode */
	uint64_t ullNewValue = (uint64_t)
	(ullReadHPETCounters() + (uint64_t)ulHPETTicksToInterrupt[TimerNumber]);
	vSetHPETComparator(TimerNumber, ullNewValue);

	__asm volatile( "sti" );
}
#endif
/*-----------------------------------------------------------*/

#if( hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
	extern void vApplicationHPETTimer0Handler( void );
	static void vHPETIRQHandler0( void )
	{
		vHPET_ISR( 0 );
		vApplicationHPETTimer0Handler();
		hpetIO_APIC_EOI = hpetHPET_TIMER0_ISR_VECTOR;
	}
#endif
/*-----------------------------------------------------------*/

#if( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
	extern void vApplicationHPETTimer1Handler( void );
	void vHPETIRQHandler1( void )
	{
		vHPET_ISR( 1 );
		vApplicationHPETTimer1Handler();
		hpetIO_APIC_EOI = hpetHPET_TIMER1_ISR_VECTOR;
	}
#endif
/*-----------------------------------------------------------*/

#if( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
	extern void vApplicationHPETTimer2Handler( void );
	static void vHPETIRQHandler2( void )
	{
		vHPET_ISR( 2 );
		vApplicationHPETTimer2Handler();
		hpetIO_APIC_EOI = hpetHPET_TIMER2_ISR_VECTOR;
	}
#endif

/*-----------------------------------------------------------------------
 * Print HPET information functions
 *------------------------------------------------------------------------
 */
#if ((hpetHPET_PRINT_INFO == 1 ) && (hpetHPET_TIMER_IN_USE))
static void prvUpdateHPETInfoTask( void *pvParameters )
{
TickType_t xNextWakeTime, xBlockTime;
uint32_t TimerNumber;
uint8_t row, col, execute;
struct hpet_info *pi;

	/* Remove compiler warning about unused parameter. */
	( void ) pvParameters;

	/* Initialise xNextWakeTime - this only needs to be done once. */
	xNextWakeTime = xTaskGetTickCount();

	/* Set task blocking period. */
	xBlockTime = pdMS_TO_TICKS( 500 );

	for( ;; )
	{
		/* Place this task in the blocked state until it is time to run again. */
		vTaskDelayUntil( &xNextWakeTime, xBlockTime );

		/* Print all information */
		for (TimerNumber = 0; TimerNumber <= 2; TimerNumber++)
		{
			execute = pdFALSE;
			pi = &PrintInfo[TimerNumber];
			pi->timer_number = TimerNumber;
			pi->main_counter_h = hpetHPET_MAIN_CTR_HIGH;
			pi->main_counter_l = hpetHPET_MAIN_CTR_LOW;
			pi->total_interrupts = ulHPETTotalInterrupts[TimerNumber];
			pi->elapsed_seconds = ulHPETElapsedSeconds[TimerNumber];
			#if (hpetUSE_HPET_TIMER_NUMBER_0 == 1 )
				if(TimerNumber == 0)
				{
					row = 9 ; col = 1;
					pi->comparator_h = hpetHPET_TMR0_COMPARATOR_HIGH;
					pi->comparator_l = hpetHPET_TMR0_COMPARATOR_LOW;
					execute = pdTRUE;
				}
			#endif
			#if ( hpetUSE_HPET_TIMER_NUMBER_1 == 1 )
				if(TimerNumber == 1)
				{
					row = 13 ; col = 1;
					pi->comparator_h = hpetHPET_TMR1_COMPARATOR_HIGH;
					pi->comparator_l = hpetHPET_TMR1_COMPARATOR_LOW;
					execute = pdTRUE;
				}
			#endif
			#if ( hpetUSE_HPET_TIMER_NUMBER_2 == 1 )
				if(TimerNumber == 2)
				{
					row = 17 ; col = 1;
					pi->comparator_h = hpetHPET_TMR2_COMPARATOR_HIGH;
					pi->comparator_l = hpetHPET_TMR2_COMPARATOR_LOW;
					execute = pdTRUE;
				}
			#endif

			/* Print information on screen */
			if(execute == pdTRUE)
			{
				g_printf_rcc(row, col, ANSI_COLOR_WHITE,
				" HPE Timer Number = %d", pi->timer_number);
				g_printf_rcc(row+1, col, ANSI_COLOR_WHITE,
				" Timer Counters   = 0x%08x:%08x, Comparator      = 0x%08x:%08x",
				pi->main_counter_h, pi->main_counter_l,
				pi->comparator_h, pi->comparator_l);
				g_printf_rcc(row+2, col, ANSI_COLOR_WHITE,
				" Total Interrupts = 0x%08x           Elapsed Seconds = %u",
				pi->total_interrupts, pi->elapsed_seconds);
				g_printf_rcc(row+3, col, DEFAULT_SCREEN_COLOR , "\r");
			}
		}
	}
}
#endif
/*-----------------------------------------------------------*/

void vCreateHPETInfoUpdateTask( void  )
{
#if ((hpetHPET_PRINT_INFO == 1 ) && (hpetHPET_TIMER_IN_USE))
	/* Create the task that displays HPE timer information. */
	xTaskCreate( prvUpdateHPETInfoTask, "HPETInfo", (configMINIMAL_STACK_SIZE << 1),
	NULL, (tskIDLE_PRIORITY), NULL );
#endif
}
/*-----------------------------------------------------------*/