diff options
Diffstat (limited to 'cpu/arm925t/timer.c')
-rw-r--r-- | cpu/arm925t/timer.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/cpu/arm925t/timer.c b/cpu/arm925t/timer.c new file mode 100644 index 0000000..c16ef25 --- /dev/null +++ b/cpu/arm925t/timer.c @@ -0,0 +1,137 @@ +/* + * (C) Copyright 2009 + * 2N Telekomunikace, <www.2n.cz> + * + * (C) Copyright 2003 + * Texas Instruments, <www.ti.com> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Marius Groeger <mgroeger@sysgo.de> + * + * (C) Copyright 2002 + * Sysgo Real-Time Solutions, GmbH <www.elinos.com> + * Alex Zuepke <azu@sysgo.de> + * + * (C) Copyright 2002 + * Gary Jennejohn, DENX Software Engineering, <garyj@denx.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 <common.h> +#include <arm925t.h> +#include <configs/omap1510.h> +#include <asm/io.h> + +#define TIMER_LOAD_VAL 0xffffffff +#define TIMER_CLOCK (CONFIG_SYS_CLK_FREQ / (2 << CONFIG_SYS_PTV)) + +static uint32_t timestamp; +static uint32_t lastdec; + +/* nothing really to do with interrupts, just starts up a counter. */ +int timer_init (void) +{ + /* Start the decrementer ticking down from 0xffffffff */ + __raw_writel(TIMER_LOAD_VAL, CONFIG_SYS_TIMERBASE + LOAD_TIM); + __raw_writel(MPUTIM_ST | MPUTIM_AR | MPUTIM_CLOCK_ENABLE | + (CONFIG_SYS_PTV << MPUTIM_PTV_BIT), + CONFIG_SYS_TIMERBASE + CNTL_TIMER); + + /* init the timestamp and lastdec value */ + reset_timer_masked(); + + return 0; +} + +/* + * timer without interrupts + */ + +void reset_timer (void) +{ + reset_timer_masked (); +} + +ulong get_timer (ulong base) +{ + return get_timer_masked () - base; +} + +void set_timer (ulong t) +{ + timestamp = t; +} + +/* delay x useconds AND preserve advance timestamp value */ +void udelay (unsigned long usec) +{ + int32_t tmo = usec * (TIMER_CLOCK / 1000) / 1000; + uint32_t now, last = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM); + + while (tmo > 0) { + now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM); + if (last < now) /* count down timer underflow */ + tmo -= TIMER_LOAD_VAL - now + last; + else + tmo -= last - now; + last = now; + } +} + +void reset_timer_masked (void) +{ + /* reset time */ + lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) / + (TIMER_CLOCK / CONFIG_SYS_HZ); + timestamp = 0; /* start "advancing" time stamp from 0 */ +} + +ulong get_timer_masked (void) +{ + uint32_t now = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM) / + (TIMER_CLOCK / CONFIG_SYS_HZ); + if (lastdec < now) /* count down timer underflow */ + timestamp += TIMER_LOAD_VAL / (TIMER_CLOCK / CONFIG_SYS_HZ) - + now + lastdec; + else + timestamp += lastdec - now; + lastdec = now; + + return timestamp; +} + +/* + * This function is derived from PowerPC code (read timebase as long long). + * On ARM it just returns the timer value. + */ +unsigned long long get_ticks(void) +{ + return get_timer(0); +} + +/* + * 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) +{ + return CONFIG_SYS_HZ; +} |