/*
 * Milkymist SoC (Software)
 * Copyright (C) 2012 Sebastien Bourdeauducq
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 3 of the License.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <hw/timer.h>
#include <hw/id.h>

#include "timer.h"

unsigned int get_system_frequency(void)
{
	return (CSR_ID_FREQ3 << 24)
		|(CSR_ID_FREQ2 << 16)
		|(CSR_ID_FREQ1 << 8)
		|CSR_ID_FREQ0;
}

void timer_enable(int en)
{
	CSR_TIMER0_EN = en;
}

unsigned int timer_get(void)
{
	return (CSR_TIMER0_COUNT3 << 24)
		|(CSR_TIMER0_COUNT2 << 16)
		|(CSR_TIMER0_COUNT1 << 8)
		|CSR_TIMER0_COUNT0;
}

void timer_set_counter(unsigned int value)
{
	CSR_TIMER0_COUNT3 = (value & 0xff000000) >> 24;
	CSR_TIMER0_COUNT2 = (value & 0x00ff0000) >> 16;
	CSR_TIMER0_COUNT1 = (value & 0x0000ff00) >> 8;
	CSR_TIMER0_COUNT0 = value & 0x000000ff;
}

void timer_set_reload(unsigned int value)
{
	CSR_TIMER0_RELOAD3 = (value & 0xff000000) >> 24;
	CSR_TIMER0_RELOAD2 = (value & 0x00ff0000) >> 16;
	CSR_TIMER0_RELOAD1 = (value & 0x0000ff00) >> 8;
	CSR_TIMER0_RELOAD0 = value & 0x000000ff;
}

void busy_wait(unsigned int ds)
{
	timer_enable(0);
	timer_set_reload(0);
	timer_set_counter(get_system_frequency()/10*ds);
	timer_enable(1);
	while(timer_get());
}