Re: [U-Boot] [PATCH v2] arm925t: Fix CONFIG_SYS_HZ to 1000

22 Apr 2009

Ladislav Michl wrote:
...
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
Acked-by: Dirk Behme dirk.behme@googlemail.com
...

diff --git a/cpu/arm925t/interrupts.c b/cpu/arm925t/interrupts.c
index e5c77f7..ec2a978 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.

diff --git a/include/configs/SX1.h b/include/configs/SX1.h
index caa6592..6149276 100644
--- a/include/configs/SX1.h
+++ b/include/configs/SX1.h
@@ -135,12 +135,12 @@
#define CONFIG_SYS_LOAD_ADDR		0x10000000	/* default load address */
-/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
+/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.

This time is further subdivided by a local divisor.

*/
 #define CONFIG_SYS_TIMERBASE	OMAP1510_TIMER1_BASE	/* use timer 1 */
-#define CONFIG_SYS_PTV		7	/* 2^(PTV+1), divide by 256 */
-#define CONFIG_SYS_HZ		((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
+#define CONFIG_SYS_PTV		2	/* Divisor: 2^(PTV+1) => 8 */
+#define CONFIG_SYS_HZ		1000
/*-----------------------------------------------------------------------

Stack sizes

diff --git a/include/configs/netstar.h b/include/configs/netstar.h
index 39560de..5cfee66 100644
--- a/include/configs/netstar.h
+++ b/include/configs/netstar.h
@@ -222,12 +222,12 @@
#define CONFIG_SYS_LOAD_ADDR		PHYS_SDRAM_1 + 0x400000	/* default load address */
-/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
+/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.

This time is further subdivided by a local divisor.

*/
 #define CONFIG_SYS_TIMERBASE		OMAP1510_TIMER1_BASE
-#define CONFIG_SYS_PTV			7		/* 2^(pvt+1), divide by 256 */
-#define CONFIG_SYS_HZ			((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
+#define CONFIG_SYS_PTV			7
+#define CONFIG_SYS_HZ			1000
#define OMAP5910_DPLL_DIV	1
 #define OMAP5910_DPLL_MUL	((CONFIG_SYS_CLK_FREQ * \
diff --git a/include/configs/omap1510inn.h b/include/configs/omap1510inn.h
index 6c1c5ec..8408209 100644
--- a/include/configs/omap1510inn.h
+++ b/include/configs/omap1510inn.h
@@ -132,12 +132,12 @@
#define CONFIG_SYS_LOAD_ADDR		0x10000000	/* default load address */
-/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
+/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.

This time is further subdivided by a local divisor.

*/
 #define CONFIG_SYS_TIMERBASE	OMAP1510_TIMER1_BASE	/* use timer 1 */
-#define CONFIG_SYS_PTV		7	/* 2^(PTV+1), divide by 256 */
-#define CONFIG_SYS_HZ		((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
+#define CONFIG_SYS_PTV		2	/* Divisor: 2^(PTV+1) => 8 */
+#define CONFIG_SYS_HZ		1000
/*-----------------------------------------------------------------------

Stack sizes

diff --git a/include/configs/voiceblue.h b/include/configs/voiceblue.h
index 3f97843..aa8efaa 100644
--- a/include/configs/voiceblue.h
+++ b/include/configs/voiceblue.h
@@ -210,12 +210,12 @@
 #define CONFIG_SYS_MEMTEST_START	PHYS_SDRAM_1
 #define CONFIG_SYS_MEMTEST_END		PHYS_SDRAM_1 + PHYS_SDRAM_1_SIZE - PHYS_SDRAM_1_RESERVED
-/* The 1510 has 3 timers, they can be driven by the RefClk (12Mhz) or by DPLL1.
+/* The 1510 has 3 timers, they can be driven by the RefClk (12MHz) or by DPLL1.

This time is further subdivided by a local divisor.

*/
 #define CONFIG_SYS_TIMERBASE	OMAP1510_TIMER1_BASE
 #define CONFIG_SYS_PTV		7	/* 2^(PTV+1), divide by 256 */
-#define CONFIG_SYS_HZ		((CONFIG_SYS_CLK_FREQ)/(2 << CONFIG_SYS_PTV))
+#define CONFIG_SYS_HZ		1000
#define OMAP5910_DPLL_DIV	1
 #define OMAP5910_DPLL_MUL	((CONFIG_SYS_CLK_FREQ * \

    