diff options
Diffstat (limited to 'cpu/arm926ejs/davinci/timer.c')
| -rw-r--r-- | cpu/arm926ejs/davinci/timer.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/cpu/arm926ejs/davinci/timer.c b/cpu/arm926ejs/davinci/timer.c index c6b1dda51..4a1a54dcf 100644 --- a/cpu/arm926ejs/davinci/timer.c +++ b/cpu/arm926ejs/davinci/timer.c @@ -61,6 +61,11 @@ davinci_timer *timer = (davinci_timer *)CFG_TIMERBASE; #define TIMER_LOAD_VAL (CFG_HZ_CLOCK / CFG_HZ) #define READ_TIMER timer->tim34 +/* Timer runs with CFG_HZ_CLOCK, currently 27MHz. To avoid wrap + around of timestamp already after min ~159s, divide it, e.g. by 16. + timestamp will then wrap around all min ~42min */ +#define DIV(x) ((x) >> 4) + static ulong timestamp; static ulong lastinc; @@ -101,20 +106,20 @@ void udelay(unsigned long usec) void reset_timer_masked(void) { - lastinc = READ_TIMER; + lastinc = DIV(READ_TIMER); timestamp = 0; } ulong get_timer_raw(void) { - ulong now = READ_TIMER; + ulong now = DIV(READ_TIMER); if (now >= lastinc) { /* normal mode */ timestamp += now - lastinc; } else { /* overflow ... */ - timestamp += now + TIMER_LOAD_VAL - lastinc; + timestamp += now + DIV(TIMER_LOAD_VAL) - lastinc; } lastinc = now; return timestamp; @@ -122,7 +127,7 @@ ulong get_timer_raw(void) ulong get_timer_masked(void) { - return(get_timer_raw() / TIMER_LOAD_VAL); + return(get_timer_raw() / DIV(TIMER_LOAD_VAL)); } void udelay_masked(unsigned long usec) |