diff options
Diffstat (limited to 'arch/x86/cpu/sc520/sc520_timer.c')
| -rw-r--r-- | arch/x86/cpu/sc520/sc520_timer.c | 90 | 
1 files changed, 90 insertions, 0 deletions
| diff --git a/arch/x86/cpu/sc520/sc520_timer.c b/arch/x86/cpu/sc520/sc520_timer.c new file mode 100644 index 000000000..1bcfe67c9 --- /dev/null +++ b/arch/x86/cpu/sc520/sc520_timer.c @@ -0,0 +1,90 @@ +/* + * (C) Copyright 2008-2011 + * Graeme Russ, <graeme.russ@gmail.com> + * + * (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 + */ + +#include <common.h> +#include <asm/io.h> +#include <asm/interrupt.h> +#include <asm/ic/sc520.h> + +void sc520_timer_isr(void) +{ +	/* Ack the GP Timer Interrupt */ +	writeb(0x02, &sc520_mmcr->gptmrsta); +} + +int timer_init(void) +{ +	/* 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); + +	/* Map GP Timer 1 to Master PIC IR0  */ +	writeb(0x01, &sc520_mmcr->gp_tmr_int_map[1]); + +	/* Disable GP Timers 1 & 2 - Allow configuration writes */ +	writew(0x4000, &sc520_mmcr->gptmr1ctl); +	writew(0x4000, &sc520_mmcr->gptmr2ctl); + +	/* Reset GP Timers 1 & 2 */ +	writew(0x0000, &sc520_mmcr->gptmr1cnt); +	writew(0x0000, &sc520_mmcr->gptmr2cnt); + +	/* Setup GP Timer 2 as a 100kHz (10us) prescaler */ +	writew(83, &sc520_mmcr->gptmr2maxcmpa); +	writew(0xc001, &sc520_mmcr->gptmr2ctl); + +	/* Setup GP Timer 1 as a 1000 Hz (1ms) interrupt generator */ +	writew(100, &sc520_mmcr->gptmr1maxcmpa); +	writew(0xe009, &sc520_mmcr->gptmr1ctl); + +	unmask_irq (0); + +	/* Clear the GP Timer 1 status register to get the show rolling*/ +	writeb(0x02, &sc520_mmcr->gptmrsta); + +	return 0; +} + +/* Allow boards to override udelay implementation */ +void __udelay(unsigned long usec) +	__attribute__((weak, alias("sc520_udelay"))); + +void sc520_udelay(unsigned long usec) +{ +	int m = 0; +	long u; +	long temp; + +	temp = readw(&sc520_mmcr->swtmrmilli); +	temp = readw(&sc520_mmcr->swtmrmicro); + +	do { +		m += readw(&sc520_mmcr->swtmrmilli); +		u = readw(&sc520_mmcr->swtmrmicro) + (m * 1000); +	} while (u < usec); +} |