diff options
| author | Pavel Machek <pavel@denx.de> | 2014-07-13 13:14:27 +0200 |
|---|---|---|
| committer | Tom Rini <trini@ti.com> | 2014-07-22 07:44:26 -0400 |
| commit | fccacd3b4cffb5b3d50fe5e68ceb3604138041df (patch) | |
| tree | 84fecdb17b2bacfd33519d0cbbbd8c1fb5ae4d1e /lib | |
| parent | 288afdc9b97f00fa8422ea065e135f8423441cd7 (diff) | |
lib/time.c cleanups
As I initially suspected overflow in time handling, I took a detailed
look at lib/time.c. This adds comments about units being used, reduces
amount of type casting being done, and makes __udelay() always wait at
least one tick. (Current code could do no delaying at all for short
delays).
Signed-off-by: Pavel Machek <pavel@denx.de>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/time.c | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/lib/time.c b/lib/time.c index 73c3b6ad7ff..c7b026498be 100644 --- a/lib/time.c +++ b/lib/time.c @@ -15,12 +15,13 @@ #endif #ifndef CONFIG_WD_PERIOD -# define CONFIG_WD_PERIOD (10 * 1000 * 1000) /* 10 seconds default*/ +# define CONFIG_WD_PERIOD (10 * 1000 * 1000) /* 10 seconds default */ #endif DECLARE_GLOBAL_DATA_PTR; #ifdef CONFIG_SYS_TIMER_RATE +/* Returns tick rate in ticks per second */ ulong notrace get_tbclk(void) { return CONFIG_SYS_TIMER_RATE; @@ -51,9 +52,10 @@ unsigned long long __weak notrace get_ticks(void) return ((unsigned long long)gd->timebase_h << 32) | gd->timebase_l; } -static unsigned long long notrace tick_to_time(uint64_t tick) +/* Returns time in milliseconds */ +static unsigned long long notrace tick_to_time(unsigned long long tick) { - unsigned int div = get_tbclk(); + ulong div = get_tbclk(); tick *= CONFIG_SYS_HZ; do_div(tick, div); @@ -65,6 +67,7 @@ int __weak timer_init(void) return 0; } +/* Returns time in milliseconds */ ulong __weak get_timer(ulong base) { return tick_to_time(get_ticks()) - base; @@ -74,9 +77,10 @@ unsigned long __weak notrace timer_get_us(void) { return tick_to_time(get_ticks() * 1000); } + static unsigned long long usec_to_tick(unsigned long usec) { - uint64_t tick = usec; + unsigned long long tick = usec; tick *= get_tbclk(); do_div(tick, 1000000); return tick; @@ -85,12 +89,10 @@ static unsigned long long usec_to_tick(unsigned long usec) void __weak __udelay(unsigned long usec) { unsigned long long tmp; - ulong tmo; - tmo = usec_to_tick(usec); - tmp = get_ticks() + tmo; /* get current timestamp */ + tmp = get_ticks() + usec_to_tick(usec); /* get current timestamp */ - while (get_ticks() < tmp) /* loop till event */ + while (get_ticks() < tmp+1) /* loop till event */ /*NOP*/; } |