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-rw-r--r--arch/arm/cpu/arm920t/a320/timer.c134
1 files changed, 50 insertions, 84 deletions
diff --git a/arch/arm/cpu/arm920t/a320/timer.c b/arch/arm/cpu/arm920t/a320/timer.c
index 443d31d..4bfcef2 100644
--- a/arch/arm/cpu/arm920t/a320/timer.c
+++ b/arch/arm/cpu/arm920t/a320/timer.c
@@ -18,20 +18,35 @@
*/
#include <common.h>
+#include <div64.h>
#include <asm/io.h>
#include <faraday/ftpmu010.h>
#include <faraday/fttmr010.h>
-static ulong timestamp;
-static ulong lastdec;
-
-static struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+DECLARE_GLOBAL_DATA_PTR;
#define TIMER_CLOCK 32768
#define TIMER_LOAD_VAL 0xffffffff
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+ tick *= CONFIG_SYS_HZ;
+ do_div(tick, gd->timer_rate_hz);
+
+ return tick;
+}
+
+static inline unsigned long long usec_to_tick(unsigned long long usec)
+{
+ usec *= gd->timer_rate_hz;
+ do_div(usec, 1000000);
+
+ return usec;
+}
+
int timer_init(void)
{
+ struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
unsigned int cr;
debug("%s()\n", __func__);
@@ -59,106 +74,57 @@ int timer_init(void)
cr |= FTTMR010_TM3_ENABLE;
writel(cr, &tmr->cr);
- /* init the timestamp and lastdec value */
- reset_timer_masked();
+ gd->timer_rate_hz = TIMER_CLOCK;
+ gd->tbu = gd->tbl = 0;
return 0;
}
/*
- * timer without interrupts
- */
-
-/*
- * reset time
- */
-void reset_timer_masked(void)
-{
- /* capure current decrementer value time */
- lastdec = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
- timestamp = 0; /* start "advancing" time stamp from 0 */
-
- debug("%s(): lastdec = %lx\n", __func__, lastdec);
-}
-
-/*
- * return timer ticks
- */
-ulong get_timer_masked(void)
-{
- /* current tick value */
- ulong now = readl(&tmr->timer3_counter) / (TIMER_CLOCK / CONFIG_SYS_HZ);
-
- debug("%s(): now = %lx, lastdec = %lx\n", __func__, now, lastdec);
-
- if (lastdec >= now) {
- /*
- * normal mode (non roll)
- * move stamp fordward with absoulte diff ticks
- */
- timestamp += lastdec - now;
- } else {
- /*
- * we have overflow of the count down timer
- *
- * nts = ts + ld + (TLV - now)
- * ts=old stamp, ld=time that passed before passing through -1
- * (TLV-now) amount of time after passing though -1
- * nts = new "advancing time stamp"...it could also roll and
- * cause problems.
- */
- timestamp += lastdec + TIMER_LOAD_VAL - now;
- }
-
- lastdec = now;
-
- debug("%s() returns %lx\n", __func__, timestamp);
-
- return timestamp;
-}
-
-/*
- * return difference between timer ticks and base
+ * Get the current 64 bit timer tick count
*/
-ulong get_timer(ulong base)
+unsigned long long get_ticks(void)
{
- debug("%s(%lx)\n", __func__, base);
- return get_timer_masked() - base;
+ struct fttmr010 *tmr = (struct fttmr010 *)CONFIG_FTTMR010_BASE;
+ ulong now = TIMER_LOAD_VAL - readl(&tmr->timer3_counter);
+
+ /* increment tbu if tbl has rolled over */
+ if (now < gd->tbl)
+ gd->tbu++;
+ gd->tbl = now;
+ return (((unsigned long long)gd->tbu) << 32) | gd->tbl;
}
-/* delay x useconds AND preserve advance timestamp value */
void __udelay(unsigned long usec)
{
- long tmo = usec * (TIMER_CLOCK / 1000) / 1000;
- unsigned long now, last = readl(&tmr->timer3_counter);
-
- debug("%s(%lu)\n", __func__, usec);
- while (tmo > 0) {
- now = readl(&tmr->timer3_counter);
- if (now > last) /* count down timer overflow */
- tmo -= TIMER_LOAD_VAL + last - now;
- else
- tmo -= last - now;
- last = now;
- }
+ unsigned long long start;
+ ulong tmo;
+
+ start = get_ticks(); /* get current timestamp */
+ tmo = usec_to_tick(usec); /* convert usecs to ticks */
+ while ((get_ticks() - start) < tmo)
+ ; /* loop till time has passed */
}
/*
- * This function is derived from PowerPC code (read timebase as long long).
- * On ARM it just returns the timer value.
+ * get_timer(base) can be used to check for timeouts or
+ * to measure elasped time relative to an event:
+ *
+ * ulong start_time = get_timer(0) sets start_time to the current
+ * time value.
+ * get_timer(start_time) returns the time elapsed since then.
+ *
+ * The time is used in CONFIG_SYS_HZ units!
*/
-unsigned long long get_ticks(void)
+ulong get_timer(ulong base)
{
- debug("%s()\n", __func__);
- return get_timer(0);
+ return tick_to_time(get_ticks()) - base;
}
/*
- * This function is derived from PowerPC code (timebase clock frequency).
- * On ARM it returns the number of timer ticks per second.
+ * Return the number of timer ticks per second.
*/
ulong get_tbclk(void)
{
- debug("%s()\n", __func__);
- return CONFIG_SYS_HZ;
+ return gd->timer_rate_hz;
}