arm925t: Fix CONFIG_SYS_HZ to 1000

Let CONFIG_SYS_HZ to have value of 1000 effectively fixing all users of
get_timer.

Changes since original version:
* Set PTV=2 (divisor 8) for boards using 12MHz timer clock source to
  improve timer resolution.

Signed-off-by: Ladislav Michl <ladis@linux-mips.org>

1 files changed, 24 insertions, 64 deletions

diff --git a/cpu/arm925t/interrupts.c b/cpu/arm925t/interrupts.c
index e5c77f7a0f..ec2a9789d3 100644
--- a/cpu/arm925t/interrupts.c
+++ b/cpu/arm925t/interrupts.c
@@ -1,4 +1,7 @@
 /*
+ * (C) Copyright 2009
+ * 2N Telekomunikace, <www.2n.cz>
+ *
  * (C) Copyright 2003
  * Texas Instruments, <www.ti.com>
  *
@@ -37,7 +40,8 @@
 #include <configs/omap1510.h>
 #include <asm/io.h>
 
-#define TIMER_LOAD_VAL 0xffffffff
+#define TIMER_LOAD_VAL	0xffffffff
+#define TIMER_CLOCK	(CONFIG_SYS_CLK_FREQ / (2 << CONFIG_SYS_PTV))
 
 static uint32_t timestamp;
 static uint32_t lastdec;
@@ -79,85 +83,41 @@ void set_timer (ulong t)
 /* delay x useconds AND preserve advance timestamp value */
 void udelay (unsigned long usec)
 {
-	ulong tmo, tmp;
-
-	if (usec >= 1000) {		/* if "big" number, spread normalization to seconds */
-		tmo = usec / 1000;	/* start to normalize for usec to ticks per sec */
-		tmo *= CONFIG_SYS_HZ;	/* find number of "ticks" to wait to achieve target */
-		tmo /= 1000;		/* finish normalize. */
-	} else {			/* else small number, don't kill it prior to HZ multiply */
-		tmo = usec * CONFIG_SYS_HZ;
-		tmo /= (1000*1000);
+	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;
 	}
-
-	tmp = get_timer (0);		/* get current timestamp */
-	if ((tmo + tmp + 1) < tmp)	/* if setting this fordward will roll time stamp */
-		reset_timer_masked ();	/* reset "advancing" timestamp to 0, set lastdec value */
-	else
-		tmo += tmp;		/* else, set advancing stamp wake up time */
-
-	while (get_timer_masked () < tmo) /* loop till event */
-		/*NOP*/;
 }
 
 void reset_timer_masked (void)
 {
 	/* reset time */
-	lastdec = __raw_readl(CONFIG_SYS_TIMERBASE + READ_TIM);
+	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);
-
-	if (lastdec >= now) {		/* normal mode (non roll) */
-		/* normal mode */
-		timestamp += lastdec - now; /* move stamp fordward with absoulte diff ticks */
-	} 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;
-	}
+	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;
 }
 
-/* waits specified delay value and resets timestamp */
-void udelay_masked (unsigned long usec)
-{
-#ifdef CONFIG_INNOVATOROMAP1510
-	#define LOOPS_PER_MSEC 60 /* tuned on omap1510 */
-	volatile int i, time_remaining = LOOPS_PER_MSEC*usec;
-	for (i=time_remaining; i>0; i--) { }
-#else
-
-	ulong tmo;
-	ulong endtime;
-	signed long diff;
-
-	if (usec >= 1000) {		/* if "big" number, spread normalization to seconds */
-		tmo = usec / 1000;	/* start to normalize for usec to ticks per sec */
-		tmo *= CONFIG_SYS_HZ;	/* find number of "ticks" to wait to achieve target */
-		tmo /= 1000;		/* finish normalize. */
-	} else {			/* else small number, don't kill it prior to HZ multiply */
-		tmo = usec * CONFIG_SYS_HZ;
-		tmo /= (1000*1000);
-	}
-
-	endtime = get_timer_masked () + tmo;
-
-	do {
-		ulong now = get_timer_masked ();
-		diff = endtime - now;
-	} while (diff >= 0);
-#endif
-}
-
 /*
  * This function is derived from PowerPC code (read timebase as long long).
  * On ARM it just returns the timer value.