init_qtime.c

Centrality Atlas II development software

/*
 * $QNXLicenseC: 
 * Copyright 2007,2008, QNX Software Systems.  
 *  
 * Licensed under the Apache License, Version 2.0 (the "License"). You  
 * may not reproduce, modify or distribute this software except in  
 * compliance with the License. You may obtain a copy of the License  
 * at: http://www.apache.org/licenses/LICENSE-2.0  
 *  
 * Unless required by applicable law or agreed to in writing, software  
 * distributed under the License is distributed on an "AS IS" basis,  
 * WITHOUT WARRANTIES OF ANY KIND, either express or implied. 
 * 
 * This file may contain contributions from others, either as  
 * contributors under the License or as licensors under other terms.   
 * Please review this entire file for other proprietary rights or license  
 * notices, as well as the QNX Development Suite License Guide at  
 * http://licensing.qnx.com/license-guide/ for other information. 
 * $ 
 */





/*
 * TI OMAP specific timer support
 */

#include "startup.h"
#include "atlasii.h"

extern struct callout_rtn timer_load_atlasii;
extern struct callout_rtn timer_value_atlasii;
extern struct callout_rtn timer_reload_atlasii;

#define	ATLAS_CLOCK_SCALE	-15
#define   OST_TIMER_SIZE		0x40
static uintptr_t	timer_base;
extern unsigned long atlasii_clock(int OP) ;
	
static const struct callout_slot	timer_callouts[] = {
	{ CALLOUT_SLOT(timer_load, _atlasii) },
	{ CALLOUT_SLOT(timer_value, _atlasii) },
	{ CALLOUT_SLOT(timer_reload, _atlasii) },
};

static unsigned
timer_start_atlasii()
{
	out32(timer_base + 0x30, 1 );
	//TIMER_LATCH =1;
	return in32(timer_base + 0x34 );
}

static unsigned
timer_diff_atlasii(unsigned start)
{
	unsigned now;
	out32(timer_base + 0x30, 1 );
	now= in32(timer_base  + 0x34 );
	return start - now;
}

void
init_qtime()
{
	unsigned long timer_clock=atlasii_clock(1)>>1; //equal to sys clock/2
	struct qtime_entry	*qtime = alloc_qtime();
	
	/*
	 * Map the timer 0 registers
	 */
	timer_base = startup_io_map(OST_TIMER_SIZE, _OST_MODULE_BASE);

	/*clear any existing interrupt*/
	out32(timer_base +0x20, 0x3f);

	//We divide the sys clock to half to get os timer clock (DIV=(SYSCLK/TIMERCLK)/2-1)
	out32(timer_base +0x2C, 0);  

	//Enable TIMER_MATCH_0 timer interrupt
	out32(timer_base +0x24, 0x1);  
	//TIMER_INT_EN = 0x1;

	//clear Counter Low & Hi
	out32(timer_base +0x4, 0x0);  
	out32(timer_base +0x0, 0x0);  
	
	timer_start = timer_start_atlasii;
	timer_diff  = timer_diff_atlasii;

	qtime->intr = 28;

	qtime->timer_rate = ((uint64_t)1000000000000000ULL)/((uint64_t)timer_clock);
	qtime->timer_scale = ATLAS_CLOCK_SCALE;
	qtime->cycles_per_sec =timer_clock;

	add_callout_array(timer_callouts, sizeof(timer_callouts)); 
}