diff options
Diffstat (limited to 'arch/arm/cpu/arm926ejs/mb86r0x/timer.c')
| -rw-r--r-- | arch/arm/cpu/arm926ejs/mb86r0x/timer.c | 142 | 
1 files changed, 142 insertions, 0 deletions
| diff --git a/arch/arm/cpu/arm926ejs/mb86r0x/timer.c b/arch/arm/cpu/arm926ejs/mb86r0x/timer.c new file mode 100644 index 000000000..9175b71d1 --- /dev/null +++ b/arch/arm/cpu/arm926ejs/mb86r0x/timer.c @@ -0,0 +1,142 @@ +/* + * (C) Copyright 2007-2008 + * Stelian Pop <stelian.pop@leadtechdesign.com> + * Lead Tech Design <www.leadtechdesign.com> + * + * (C) Copyright 2010 + * Matthias Weisser, Graf-Syteco <weisserm@arcor.de> + * + * 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 <div64.h> +#include <common.h> +#include <asm/io.h> +#include <asm/arch/hardware.h> + +#define TIMER_LOAD_VAL	0xffffffff +#define TIMER_FREQ	(CONFIG_MB86R0x_IOCLK  / 256) + +static unsigned long long timestamp; +static ulong lastdec; + +static inline unsigned long long tick_to_time(unsigned long long tick) +{ +	tick *= CONFIG_SYS_HZ; +	do_div(tick, TIMER_FREQ); + +	return tick; +} + +static inline unsigned long long usec_to_tick(unsigned long long usec) +{ +	usec *= TIMER_FREQ; +	do_div(usec, 1000000); + +	return usec; +} + +/* nothing really to do with interrupts, just starts up a counter. */ +int timer_init(void) +{ +	struct mb86r0x_timer * timer = (struct mb86r0x_timer *) +					MB86R0x_TIMER_BASE; +	ulong ctrl = readl(&timer->control); + +	writel(TIMER_LOAD_VAL, &timer->load); + +	ctrl |= MB86R0x_TIMER_ENABLE | MB86R0x_TIMER_PRS_8S | +		MB86R0x_TIMER_SIZE_32; + +	writel(ctrl, &timer->control); + +	reset_timer_masked(); + +	return 0; +} + +/* + * timer without interrupts + */ +unsigned long long get_ticks(void) +{ +	struct mb86r0x_timer * timer = (struct mb86r0x_timer *) +					MB86R0x_TIMER_BASE; +	ulong now = readl(&timer->value); + +	if (now <= lastdec) { +		/* normal mode (non roll) */ +		/* move stamp forward with absolut diff ticks */ +		timestamp += lastdec - now; +	} else { +		/* we have rollover of incrementer */ +		timestamp += lastdec + TIMER_LOAD_VAL - now; +	} +	lastdec = now; +	return timestamp; +} + +void reset_timer_masked(void) +{ +	struct mb86r0x_timer * timer = (struct mb86r0x_timer *) +					MB86R0x_TIMER_BASE; + +	/* capture current value time */ +	lastdec = readl(&timer->value); +	timestamp = 0; /* start "advancing" time stamp from 0 */ +} + +ulong get_timer_masked(void) +{ +	return tick_to_time(get_ticks()); +} + +void __udelay(unsigned long usec) +{ +	unsigned long long tmp; +	ulong tmo; + +	tmo = usec_to_tick(usec); +	tmp = get_ticks();			/* get current timestamp */ + +	while ((get_ticks() - tmp) < tmo)	/* loop till event */ +		 /*NOP*/; +} + +void reset_timer(void) +{ +	reset_timer_masked(); +} + +ulong get_timer(ulong base) +{ +	return get_timer_masked() - base; +} + +/* + * This function is derived from PowerPC code (timebase clock frequency). + * On ARM it returns the number of timer ticks per second. + */ +ulong get_tbclk(void) +{ +	ulong tbclk; + +	tbclk = TIMER_FREQ; +	return tbclk; +} |