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/*
* (C) Copyright 2002
* Daniel Engström, Omicron Ceti AB <daniel@omicron.se>.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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; either version 2 of
* the License, or (at your option) any later version.
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
/* stuff specific for the sc520, but independent of implementation */
#include <common.h>
#include <asm/interrupt.h>
#include <asm/ic/sc520.h>
void sc520_timer_isr(void)
{
/* Ack the GP Timer Interrupt */
write_mmcr_byte (SC520_GPTMRSTA, 0x02);
}
int timer_init(void)
{
/* Map GP Timer 1 to Master PIC IR0 */
write_mmcr_byte (SC520_GPTMR1MAP, 0x01);
/* Disable GP Timers 1 & 2 - Allow configuration writes */
write_mmcr_word (SC520_GPTMR1CTL, 0x4000);
write_mmcr_word (SC520_GPTMR2CTL, 0x4000);
/* Reset GP Timers 1 & 2 */
write_mmcr_word (SC520_GPTMR1CNT, 0x0000);
write_mmcr_word (SC520_GPTMR2CNT, 0x0000);
/* Setup GP Timer 2 as a 100kHz (10us) prescaler */
write_mmcr_word (SC520_GPTMR2MAXCMPA, 83);
write_mmcr_word (SC520_GPTMR2CTL, 0xc001);
/* Setup GP Timer 1 as a 1000 Hz (1ms) interrupt generator */
write_mmcr_word (SC520_GPTMR1MAXCMPA, 100);
write_mmcr_word (SC520_GPTMR1CTL, 0xe009);
/* Clear the GP Timers status register */
write_mmcr_byte (SC520_GPTMRSTA, 0x07);
/* Register the SC520 specific timer interrupt handler */
register_timer_isr (sc520_timer_isr);
/* Install interrupt handler for GP Timer 1 */
irq_install_handler (0, timer_isr, NULL);
unmask_irq (0);
return 0;
}
void udelay(unsigned long usec)
{
int m = 0;
long u;
read_mmcr_word (SC520_SWTMRMILLI);
read_mmcr_word (SC520_SWTMRMICRO);
do {
m += read_mmcr_word (SC520_SWTMRMILLI);
u = read_mmcr_word (SC520_SWTMRMICRO) + (m * 1000);
} while (u < usec);
}
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