//=============================================================================
//
//      external_timer.c - Cyclone Diagnostics
//
//=============================================================================
//####COPYRIGHTBEGIN####
//                                                                          
// -------------------------------------------                              
// The contents of this file are subject to the Red Hat eCos Public License 
// Version 1.1 (the "License"); you may not use this file except in         
// compliance with the License.  You may obtain a copy of the License at    
// http://www.redhat.com/                                                   
//                                                                          
// Software distributed under the License is distributed on an "AS IS"      
// basis, WITHOUT WARRANTY OF ANY KIND, either express or implied.  See the 
// License for the specific language governing rights and limitations under 
// the License.                                                             
//                                                                          
// The Original Code is eCos - Embedded Configurable Operating System,      
// released September 30, 1998.                                             
//                                                                          
// The Initial Developer of the Original Code is Red Hat.                   
// Portions created by Red Hat are                                          
// Copyright (C) 2001 Red Hat, Inc.                             
// All Rights Reserved.                                                     
// -------------------------------------------                              
//                                                                          
//####COPYRIGHTEND####
//=============================================================================
//#####DESCRIPTIONBEGIN####
//
// Author(s):   Scott Coulter, Jeff Frazier, Eric Breeden
// Contributors:
// Date:        2001-01-25
// Purpose:     
// Description: 
//
//####DESCRIPTIONEND####
//
//===========================================================================*/

#include "iq80310.h"


extern int enable_external_interrupt (int int_id);
extern int disable_external_interrupt (int int_id);

extern int isr_connect(int int_num, void (*handler)(int), int arg);
extern int isr_disconnect(int int_num);


/* 01/05/01 jwf */
/* extern void _restart_tmr(); */


volatile int timer_ticks;


/* interrupt handler for the PAL-based external timer */
void ext_timer_handler (int arg)
{
	/* increment tick counter */
	timer_ticks++;

	/* to clear the timer interrupt, clear the timer interrupt
	   enable, then re-set the int. enable bit */
/* 01/05/01 jwf */
/*	_restart_tmr(); */

	EXT_TIMER_INT_DISAB();
	EXT_TIMER_INT_ENAB();

	return;
}


/* timer count must be written 8 bits at a time */
void write_timer_count (UINT32 count)
{
	UINT8 cnt_word;

	/* first ensure that there are only 22 bits of count data */
	count &= 0x003fffff;

	/* grab least significant 8 bits of timer value */
	cnt_word = (UINT8)(count & 0xff);
	*TIMER_LA0_REG_ADDR = cnt_word;

	/* grab next 8 bits of timer value */
	count = (count >> 8);
	cnt_word = (UINT8)(count & 0xff);
	*TIMER_LA1_REG_ADDR = cnt_word;

	/* grab last 6 bits of timer value */
	count = (count >> 8);
	cnt_word = (UINT8)(count & 0x3f);
	*TIMER_LA2_REG_ADDR = cnt_word;

	return;
}

/* timer must be read 6 bits at a time */
UINT32 read_timer_count (void)
{
	UINT8 timer_cnt0, timer_cnt1, timer_cnt2, timer_cnt3;
	UINT8 timer_byte0, timer_byte1, timer_byte2;
	UINT32 count;

	/* first read latches the count */
	timer_cnt0 = (*TIMER_LA0_REG_ADDR & TIMER_COUNT_MASK);
	timer_cnt1 = (*TIMER_LA1_REG_ADDR & TIMER_COUNT_MASK);
	timer_cnt2 = (*TIMER_LA2_REG_ADDR & TIMER_COUNT_MASK);
	timer_cnt3 = (*TIMER_LA3_REG_ADDR & 0xf);	/* only 4 bits in most sig. */

	/* now build up the count value */
	timer_byte0 = (((timer_cnt0 & 0x20) >> 1) | (timer_cnt0 & 0x1f));
	timer_byte1 = (((timer_cnt1 & 0x20) >> 1) | (timer_cnt1 & 0x1f));
	timer_byte2 = (((timer_cnt2 & 0x20) >> 1) | (timer_cnt2 & 0x1f));

	count = ((timer_cnt3 << 18) | (timer_byte2 << 12) | (timer_byte1 << 6) |
			  timer_byte0);

	return (count);
}


/* 12/18/00 jwf */
/* This test reads the timer la0-la3 registers on the fly while an up count is in progress. */
void counter_test (void)
{

	unsigned char TmrLa0Write=0xff; /* ff max, b0-b7, b0-b7 contain timer load data */	
	unsigned char TmrLa1Write=0xff; /* ff max, b8-b15, b0-b7 contain timer load data  */
	unsigned char TmrLa2Write=0x3f; /* 3f max, b16-b21, b0-b5 contain timer load data  */
	unsigned char TmrLa3Write=0x00; /* x - don't care */
	
	unsigned long int TmrLa0Read=0;	
	unsigned long int TmrLa1Read=0;
	unsigned long int TmrLa2Read=0;
	unsigned long int TmrLa3Read=0;

	unsigned long int temp3=0;
	unsigned long int temp4=0;

	unsigned long int CntInit=0;

	unsigned long int CurrentCount;
	unsigned long int LastCount;
	unsigned long int LastLastCount;
	
	char Error = FALSE;	/* This flag indicates a test pass(FALSE) or fail(TRUE) condition */

	unsigned long int sample;
	unsigned long int index;

	const int MAX_N_PASSES = 10;										/* N times the counter shall wrap around */
	const unsigned long int MAX_N_SAMPLES = 65536;						/* N samples to cover the full range of count, 0x3fffff/0x40 = 0xffff <--> 65535d, use 65536 to guarantee a counter wrap around occurs */
	unsigned long int MAX_N_SIZE = MAX_N_PASSES * MAX_N_SAMPLES * 4;	/* allocate 4 bytes per sample for a 0x0 - 0x3fffff count range to hold contents of registers LA0-LA3 */
	unsigned char *data;

	// Arbitrarily pick a spot in memory.
	// RedBoot won't ever use more than 1MB.
	data = (unsigned char *) MEMBASE_DRAM + (1*1024*1024);	/* sample storage area */

	if( data != NULL )
	{
		printf( "Allocated %d bytes\n", MAX_N_SIZE );

			/* load control data to disable timer enable b0=0 and timer disable interrupt b1=0, write to timer enable port */
		EXT_TIMER_INT_DISAB();
		EXT_TIMER_CNT_DISAB();

			/* write timer la0 port count data */
		*TIMER_LA0_REG_ADDR = TmrLa0Write;

			/* write timer la1 port count data */
		*TIMER_LA1_REG_ADDR = TmrLa1Write;

			/*  write timer la2 port count data */
		*TIMER_LA2_REG_ADDR = TmrLa2Write;

			/*  write timer la3 port count data */
		*TIMER_LA3_REG_ADDR = TmrLa3Write;

		CntInit = TmrLa0Write + (TmrLa1Write << 8 ) + (TmrLa2Write << 16 );

		printf("Timer load data = 0x%x\n", CntInit );

		printf("Reading Timer registers LA0-LA3 on the fly...\n");

			/* load control data to enable timer counter and write control data to start the counter */
		EXT_TIMER_CNT_ENAB();

			/* sample the timer counter on the fly and store LA0-3 register contents in an array */
		for ( sample=0, index=0 ; sample < ( MAX_N_PASSES * MAX_N_SAMPLES ) ; sample++, index += 4)

		{

				/* read LSB register first to latch 22 bits data into four la registers */
			data[index]   = *TIMER_LA0_REG_ADDR;	/* bits 0 1 2 3 4 6 contain count data b0-b5 */		

			data[index+1] = *TIMER_LA1_REG_ADDR;	/* bits 0 1 2 3 4 6 contain count data b6-b11 */

			data[index+2] = *TIMER_LA2_REG_ADDR;	/* bits 0 1 2 3 4 6 contain count data b12-b17 */

			data[index+3] = *TIMER_LA3_REG_ADDR;	/* bits 0 1 2 3 contain count data b18-b21 */
		
		}

		printf("Checking for errors...\n" );

			/* Assemble and check recorded register data for errors */
		for ( sample=0, index=0 ; sample < ( MAX_N_PASSES * MAX_N_SAMPLES ) ; sample++, index += 4)

		{

				/* Assembles counter data that was read on the fly */
				/* xbxbbbbb */
				/* 01000000 = 0x40 */
				/* 00011111 = 0x1F */
			data[index] &= 0x7f;		/* mask all unused bits */
			temp3=data[index];
			temp4=data[index];
			temp3 &= 0x40;				/* isolate bit 6 */
			temp3 = temp3 >> 1;			/* shift bit 6 to bit 5 */
			temp4 &= 0x1f;				/* isolate bits 0-4 */
			TmrLa0Read = temp3 + temp4;

			data[index+1] &= 0x7f;		/* mask all unused bits */
			temp3=data[index+1];
			temp4=data[index+1];
			temp3 &= 0x40;				/* isolate bit 6 */
			temp3 = temp3 >> 1;			/* shift bit 6 to bit 5 */
			temp4 &= 0x1f;				/* isolate bits 0-4 */
			TmrLa1Read = temp3 + temp4;

			data[index+2] &= 0x7f;		/* mask all unused bits */
			temp3=data[index+2];
			temp4=data[index+2];
			temp3 &= 0x40;				/* isolate bit 6 */
			temp3 = temp3 >> 1;			/* shift bit 6 to bit 5 */
			temp4 &= 0x1f;				/* isolate bits 0-4 */
			TmrLa2Read = temp3 + temp4;

			data[index+3] &= 0x0f;		/* mask all unused bits */
			TmrLa3Read = data[index+3];

										/* sum timer count data */
			CurrentCount = TmrLa0Read + (TmrLa1Read << 6 ) + (TmrLa2Read << 12 ) + (TmrLa3Read << 18 );

			if ( sample == 0 )
			{
				LastLastCount = 0;
				LastCount = CurrentCount;
			}

			if (sample == 1 )

			{
				LastLastCount = LastCount;
				LastCount = CurrentCount;
			}

			if ( sample > 1 )	/* check for data anomaly, is count value read 2 samples ago greater than the count value read 1 sample ago */
			{
				/* print error value (LastCount) positioned in between the previous and current values */
				if ( ( LastLastCount > LastCount ) && ( CurrentCount > LastLastCount ) )	/* show error only, do not show a counter wrap around reading, print error value (LastCount) positioned in between the previous and current values */
				{
					printf("0x%x 0x%x 0x%x \n", LastLastCount, LastCount, CurrentCount );
					Error = TRUE;	/* set flag to error condition */
				}
				LastLastCount = LastCount;
				LastCount = CurrentCount;
			}

		}

			/* load control data to stop timer b0=0 and reset timer interrupt b1=0 */
		EXT_TIMER_CNT_DISAB();

	} /* end if( data != NULL ) */
	
	else	/* data = NULL */
	{
		printf( "Cannot allocate memory.\n" );
	}

	if ( Error == TRUE )
	{
		printf("Timer LA0-3 register read test FAILED.\n");
	}
	else
	{
		printf("Timer LA0-3 register read test PASSED.\n");
	}

} /* end counter_test() */


/* initialize timer for diagnostic use */
void init_external_timer()
{

	/* disable timer in case it was running */
	EXT_TIMER_INT_DISAB();
	EXT_TIMER_CNT_DISAB();

	timer_ticks = 0;

	/* connect the timer ISR */
	isr_connect (TIMER_INT_ID, ext_timer_handler, 0);

	/* enable the external interrupt */
	if (enable_external_interrupt(TIMER_INT_ID) != OK)
		printf("ERROR enabling EXT TIMER interrupt!\n");
}


/* uninitialize timer after diagnostics */
void uninit_external_timer()
{
	
	/* disable timer */
	EXT_TIMER_INT_DISAB();
	EXT_TIMER_CNT_DISAB();

	/* disable and disconnect timer interrupts */
	disable_external_interrupt(TIMER_INT_ID);
	isr_disconnect (TIMER_INT_ID);
}


/* 02/02/01 jwf */
/* delay_ms - delay specified number of milliseconds */
void delay_ms(int num_ms)
{
UINT32 count;
int num_ticks;

	timer_ticks = 0;

	if (num_ms < 10)
		num_ticks = 1;
	else
	{
		/* num_ms must be multiple of 10 - round up */
		num_ticks = num_ms / 10;
		if (num_ms % 10)
			num_ticks++; /* round up */
	}

	/* for the test we will setup the timer to generate a 10msec tick */
	count = EXT_TIMER_10MSEC_COUNT;

	/* write the initial count to the timer */
	write_timer_count (count);

	/* enable the interrupt at the timer */
	EXT_TIMER_INT_ENAB();

	/* enable the timer to count */
	EXT_TIMER_CNT_ENAB();

	while (timer_ticks < num_ticks)
		;
	
	/* disable timer */
	EXT_TIMER_INT_DISAB();
	EXT_TIMER_CNT_DISAB();

}


/* test the 32 bit timer inside the CPLD, U17 */
void timer_test (void)
{
	volatile int i;
	UINT32 count;

	
	/*****  Perform 10 second count at 100 ticks/sec ****/

	/* for the test we will setup the timer to generate a 10msec tick */
	count = EXT_TIMER_10MSEC_COUNT;

	/* write the initial count to the timer */
	write_timer_count (count);

	/* enable the interrupt at the timer */
	EXT_TIMER_INT_ENAB();

	/* enable the timer to count */
	EXT_TIMER_CNT_ENAB();

	printf ("Counting at %d Ticks Per Second.\n", TICKS_10MSEC);
	printf ("Numbers should appear on 1 second increments...\n");

	for (i = 0; i < 10; i++)
	{
		while (timer_ticks < TICKS_10MSEC)
			;
		printf ("%d ", i);
		timer_ticks = 0;
	}

	printf ("\nDone\n\n");

	/* disable timer */
	EXT_TIMER_INT_DISAB();
	EXT_TIMER_CNT_DISAB();

	
	/*****  Perform 10 second count at 200 ticks/sec ****/

	count = EXT_TIMER_5MSEC_COUNT;
	write_timer_count (count);

	timer_ticks = 0;

	/* enable the interrupt at the timer */
	EXT_TIMER_INT_ENAB();

	/* enable the timer to count */
	EXT_TIMER_CNT_ENAB();

	printf ("Counting at %d Ticks Per Second.\n", TICKS_5MSEC);
	printf ("Numbers should appear on 1 second increments...\n");

	for (i = 0; i < 10; i++)
	{
		while (timer_ticks < TICKS_5MSEC)
			;
		printf ("%d ", i);
		timer_ticks = 0;
	}

	printf ("\nDone\n\n");

	/* disable timer */
	EXT_TIMER_INT_DISAB();
	EXT_TIMER_CNT_DISAB();

/* 12/18/00 jwf */
	uninit_external_timer();	/* disable interrupt */
	counter_test();
	init_external_timer();		/* enable interrupt */

	printf("\nExternal Timer Test Done\n");

/* 12/18/00 jwf */
	printf("\n\nStrike <CR> to exit this test." );
	while (xgetchar() != 0x0d);

	return;

} /* end timer_test() */


/* 02/07/01 jwf */
/* Use the CPLD 22 bit timer to generate a variable delay time */
/* set up the timer to generate a t msec tick, where ( 0mS < t < 127mS ) */
/* count=(33MHZ)(t/1 timer interrupt) where ( 0x0 < count <= 0x3fffff ) */
/* set total number of timer interrupts to num_tmr_int */
/* generate t(delay)=(count)(num_tmr_int) */
void time_delay (UINT32 count, volatile int num_tmr_int)
{

	/* write the initial count to the timer */
	write_timer_count (count);

	/* enable the interrupt at the timer */
	EXT_TIMER_INT_ENAB();

	/* enable the timer to count */
	EXT_TIMER_CNT_ENAB();

	/* generate tmr_int timer interrupts */
	while (timer_ticks < num_tmr_int);

	timer_ticks = 0;

	/* disable timer */
	EXT_TIMER_INT_DISAB();
	EXT_TIMER_CNT_DISAB();

} /* end time_delay() */