-unsigned long do_slow_gettimeoffset(void)
-{
- unsigned long count;
- unsigned long usec_count = 0;
-
- /* For the first call after boot */
- static unsigned long count_p = TIMER0_DIV;
- static unsigned long jiffies_p = 0;
-
- /* Cache volatile jiffies temporarily; we have IRQs turned off. */
- unsigned long jiffies_t;
-
- /* The timer interrupt comes from Etrax timer 0. In order to get
- * better precision, we check the current value. It might have
- * underflowed already though. */
- count = REG_RD(timer, regi_timer0, r_tmr0_data);
- jiffies_t = jiffies;
-
- /* Avoiding timer inconsistencies (they are rare, but they happen)
- * There is one problem that must be avoided here:
- * 1. the timer counter underflows
- */
- if( jiffies_t == jiffies_p ) {
- if( count > count_p ) {
- /* Timer wrapped, use new count and prescale.
- * Increase the time corresponding to one jiffy.
- */
- usec_count = 1000000/HZ;
- }
- } else
- jiffies_p = jiffies_t;
- count_p = count;
- /* Convert timer value to usec */
- /* 100 MHz timer, divide by 100 to get usec */
- usec_count += (TIMER0_DIV - count) / 100;
- return usec_count;
-}