diff options
Diffstat (limited to 'lib_mips')
| -rw-r--r-- | lib_mips/time.c | 31 |
1 files changed, 25 insertions, 6 deletions
diff --git a/lib_mips/time.c b/lib_mips/time.c index fe36530..1e92789 100644 --- a/lib_mips/time.c +++ b/lib_mips/time.c @@ -24,31 +24,50 @@ #include <common.h> #include <asm/mipsregs.h> +static unsigned long timestamp; + +/* how many counter cycles in a jiffy */ +#define CYCLES_PER_JIFFY (CFG_MIPS_TIMER_FREQ + CFG_HZ / 2) / CFG_HZ + /* * timer without interrupts */ int timer_init(void) { - write_c0_compare(0); - write_c0_count(0); + /* Set up the timer for the first expiration. */ + timestamp = 0; + write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY); return 0; } void reset_timer(void) { - write_c0_count(0); + timestamp = 0; + write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY); } ulong get_timer(ulong base) { - return read_c0_count() - base; + unsigned int count; + unsigned int expirelo = read_c0_compare(); + + /* Check to see if we have missed any timestamps. */ + count = read_c0_count(); + while ((count - expirelo) < 0x7fffffff) { + expirelo += CYCLES_PER_JIFFY; + timestamp++; + } + write_c0_compare(expirelo); + + return (timestamp - base); } void set_timer(ulong t) { - write_c0_count(t); + timestamp = t; + write_c0_compare(read_c0_count() + CYCLES_PER_JIFFY); } void udelay(unsigned long usec) @@ -66,7 +85,7 @@ void udelay(unsigned long usec) */ unsigned long long get_ticks(void) { - return read_c0_count(); + return get_timer(0); } /* |