diff options
Diffstat (limited to 'cpu/lh7a40x/timer.c')
| -rw-r--r-- | cpu/lh7a40x/timer.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/cpu/lh7a40x/timer.c b/cpu/lh7a40x/timer.c new file mode 100644 index 0000000..f0baf14 --- /dev/null +++ b/cpu/lh7a40x/timer.c @@ -0,0 +1,194 @@ +/* + * (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 <arm920t.h> +#include <lh7a40x.h> + +static ulong timer_load_val = 0; + +/* macro to read the 16 bit timer */ +static inline ulong READ_TIMER(void) +{ + lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR; + lh7a40x_timer_t* timer = &timers->timer1; + + return (timer->value & 0x0000ffff); +} + +static ulong timestamp; +static ulong lastdec; + +int timer_init (void) +{ + lh7a40x_timers_t* timers = LH7A40X_TIMERS_PTR; + lh7a40x_timer_t* timer = &timers->timer1; + + /* a periodic timer using the 508kHz source */ + timer->control = (TIMER_PER | TIMER_CLK508K); + + if (timer_load_val == 0) { + /* + * 10ms period with 508.469kHz clock = 5084 + */ + timer_load_val = CONFIG_SYS_HZ/100; + } + + /* load value for 10 ms timeout */ + lastdec = timer->load = timer_load_val; + + /* auto load, start timer */ + timer->control = timer->control | TIMER_EN; + timestamp = 0; + + 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; +} + +void udelay (unsigned long usec) +{ + ulong tmo,tmp; + + /* normalize */ + if (usec >= 1000) { + tmo = usec / 1000; + tmo *= CONFIG_SYS_HZ; + tmo /= 1000; + } + else { + if (usec > 1) { + tmo = usec * CONFIG_SYS_HZ; + tmo /= (1000*1000); + } + else + tmo = 1; + } + + /* check for rollover during this delay */ + tmp = get_timer (0); + if ((tmp + tmo) < tmp ) + reset_timer_masked(); /* timer would roll over */ + else + tmo += tmp; + + while (get_timer_masked () < tmo); +} + +void reset_timer_masked (void) +{ + /* reset time */ + lastdec = READ_TIMER(); + timestamp = 0; +} + +ulong get_timer_masked (void) +{ + ulong now = READ_TIMER(); + + if (lastdec >= now) { + /* normal mode */ + timestamp += (lastdec - now); + } else { + /* we have an overflow ... */ + timestamp += ((lastdec + timer_load_val) - now); + } + lastdec = now; + + return timestamp; +} + +void udelay_masked (unsigned long usec) +{ + ulong tmo; + ulong endtime; + signed long diff; + + /* normalize */ + if (usec >= 1000) { + tmo = usec / 1000; + tmo *= CONFIG_SYS_HZ; + tmo /= 1000; + } else { + if (usec > 1) { + tmo = usec * CONFIG_SYS_HZ; + tmo /= (1000*1000); + } else { + tmo = 1; + } + } + + endtime = get_timer_masked () + tmo; + + do { + ulong now = get_timer_masked (); + diff = endtime - now; + } while (diff >= 0); +} + +/* + * 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) +{ + ulong tbclk; + + tbclk = timer_load_val * 100; + + return tbclk; +} |