at91sam9/at91cap: fix CONFIG_SYS_HZ to 1000
The timer has been rewrote with a precision at ~0,18%
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Tested-by: Sergey Lapin <slapin@ossfans.org>
Tested-by: Eric BENARD <ebenard@free.fr>
diff --git a/cpu/arm926ejs/at91/timer.c b/cpu/arm926ejs/at91/timer.c
index fec545b..c84cb5e 100644
--- a/cpu/arm926ejs/at91/timer.c
+++ b/cpu/arm926ejs/at91/timer.c
@@ -27,7 +27,9 @@
#include <asm/arch/at91_pit.h>
#include <asm/arch/at91_pmc.h>
#include <asm/arch/at91_rstc.h>
+#include <asm/arch/clk.h>
#include <asm/arch/io.h>
+#include <div64.h>
/*
* We're using the AT91CAP9/SAM9 PITC in 32 bit mode, by
@@ -36,11 +38,26 @@
#define TIMER_LOAD_VAL 0xfffff
#define READ_RESET_TIMER at91_sys_read(AT91_PIT_PIVR)
#define READ_TIMER at91_sys_read(AT91_PIT_PIIR)
-#define TIMER_FREQ (AT91C_MASTER_CLOCK << 4)
-#define TICKS_TO_USEC(ticks) ((ticks) / 6)
-ulong get_timer_masked(void);
-ulong resettime;
+static ulong timestamp;
+static ulong lastinc;
+static ulong timer_freq;
+
+static inline unsigned long long tick_to_time(unsigned long long tick)
+{
+ tick *= CONFIG_SYS_HZ;
+ do_div(tick, timer_freq);
+
+ return tick;
+}
+
+static inline unsigned long long usec_to_tick(unsigned long long usec)
+{
+ usec *= timer_freq;
+ do_div(usec, 1000000);
+
+ return usec;
+}
/* nothing really to do with interrupts, just starts up a counter. */
int timer_init(void)
@@ -56,41 +73,49 @@
reset_timer_masked();
+ timer_freq = get_mck_clk_rate() >> 4;
+
return 0;
}
/*
* timer without interrupts
*/
-
-static inline ulong get_timer_raw(void)
+unsigned long long get_ticks(void)
{
ulong now = READ_TIMER;
- if (now >= resettime)
- return now - resettime;
- else
- return 0xFFFFFFFFUL - (resettime - now) ;
+ if (now >= lastinc) /* normal mode (non roll) */
+ /* move stamp forward with absolut diff ticks */
+ timestamp += (now - lastinc);
+ else /* we have rollover of incrementer */
+ timestamp += (0xFFFFFFFF - lastinc) + now;
+ lastinc = now;
+ return timestamp;
}
void reset_timer_masked(void)
{
- resettime = READ_TIMER;
+ /* reset time */
+ lastinc = READ_TIMER; /* capture current incrementer value time */
+ timestamp = 0; /* start "advancing" time stamp from 0 */
}
ulong get_timer_masked(void)
{
- return TICKS_TO_USEC(get_timer_raw());
-
+ return tick_to_time(get_ticks());
}
-void udelay_masked(unsigned long usec)
+void udelay(unsigned long usec)
{
- ulong tmp;
+ unsigned long long tmp;
+ ulong tmo;
- tmp = get_timer(0);
- while (get_timer(tmp) < usec) /* our timer works in usecs */
- ; /* NOP */
+ tmo = usec_to_tick(usec);
+ tmp = get_ticks() + tmo; /* get current timestamp */
+
+ while (get_ticks() < tmp) /* loop till event */
+ /*NOP*/;
}
void reset_timer(void)
@@ -100,26 +125,7 @@
ulong get_timer(ulong base)
{
- ulong now = get_timer_masked();
-
- if (now >= base)
- return now - base;
- else
- return TICKS_TO_USEC(0xFFFFFFFFUL) - (base - now) ;
-}
-
-void udelay(unsigned long usec)
-{
- udelay_masked(usec);
-}
-
-/*
- * 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);
+ return get_timer_masked () - base;
}
/*