diff options
Diffstat (limited to 'cpu/arm920t/s3c24x0/interrupts.c')
| -rw-r--r-- | cpu/arm920t/s3c24x0/interrupts.c | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/cpu/arm920t/s3c24x0/interrupts.c b/cpu/arm920t/s3c24x0/interrupts.c new file mode 100644 index 0000000..92298b0 --- /dev/null +++ b/cpu/arm920t/s3c24x0/interrupts.c @@ -0,0 +1,180 @@ +/* + * (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, <gj@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> +#if defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB) + +#include <arm920t.h> +#if defined(CONFIG_S3C2400) +#include <s3c2400.h> +#elif defined(CONFIG_S3C2410) +#include <s3c2410.h> +#endif + +extern void reset_cpu(ulong addr); +int timer_load_val = 0; + +/* macro to read the 16 bit timer */ +static inline ulong READ_TIMER(void) +{ + S3C24X0_TIMERS * const timers = S3C24X0_GetBase_TIMERS(); + + return (timers->TCNTO4 & 0xffff); +} + +static ulong timestamp; +static ulong lastdec; + +int interrupt_init (void) +{ + S3C24X0_TIMERS * const timers = S3C24X0_GetBase_TIMERS(); + + /* use PWM Timer 4 because it has no output */ + /* prescaler for Timer 4 is 16 */ + timers->TCFG0 = 0x0f00; + if (timer_load_val == 0) + { + /* + * for 10 ms clock period @ PCLK with 4 bit divider = 1/2 + * (default) and prescaler = 16. Should be 10390 + * @33.25MHz and 15625 @ 50 MHz + */ + timer_load_val = get_PCLK()/(2 * 16 * 100); + } + /* load value for 10 ms timeout */ + lastdec = timers->TCNTB4 = timer_load_val; + /* auto load, manual update of Timer 4 */ + timers->TCON = (timers->TCON & ~0x0700000) | 0x600000; + /* auto load, start Timer 4 */ + timers->TCON = (timers->TCON & ~0x0700000) | 0x500000; + 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; + ulong start = get_timer(0); + + tmo = usec / 1000; + tmo *= (timer_load_val * 100); + tmo /= 1000; + + while ((ulong)(get_timer_masked () - start) < tmo) + /*NOP*/; +} + +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; + + tmo = usec / 1000; + tmo *= (timer_load_val * 100); + tmo /= 1000; + + reset_timer_masked (); + + while (get_timer_masked () < tmo) + /*NOP*/; +} + +/* + * 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; + +#if defined(CONFIG_SMDK2400) || defined(CONFIG_TRAB) + tbclk = timer_load_val * 100; +#elif defined(CONFIG_SMDK2410) || defined(CONFIG_VCMA9) + tbclk = CFG_HZ; +#else +# error "tbclk not configured" +#endif + + return tbclk; +} + +#endif /* defined(CONFIG_S3C2400) || defined (CONFIG_S3C2410) || defined (CONFIG_TRAB) */ |