- u32 count;
- unsigned long res, tmp;
- unsigned long r0;
-
- /* Last jiffy when do_fast_gettimeoffset() was called. */
- static unsigned long last_jiffies=0;
- unsigned long quotient;
-
- /*
- * Cached "1/(clocks per usec)*2^32" value.
- * It has to be recalculated once each jiffy.
- */
- static unsigned long cached_quotient=0;
-
- tmp = jiffies;
-
- quotient = cached_quotient;
-
- if (tmp && last_jiffies != tmp) {
- last_jiffies = tmp;
- if (last_jiffies != 0) {
- r0 = div64_32(timerhi, timerlo, tmp);
- quotient = div64_32(USECS_PER_JIFFY, USECS_PER_JIFFY_FRAC, r0);
- cached_quotient = quotient;
- }
- }
-
- /* Get last timer tick in absolute kernel time */
- count = read_c0_count();
-
- /* .. relative to previous jiffy (32 bits is enough) */
- count -= timerlo;
-
- __asm__("multu\t%1,%2\n\t"
- "mfhi\t%0"
- : "=r" (res)
- : "r" (count), "r" (quotient)
- : "hi", "lo", GCC_REG_ACCUM);
-
- /*
- * Due to possible jiffies inconsistencies, we need to check
- * the result so that we'll get a timer that is monotonic.
- */
- if (res >= USECS_PER_JIFFY)
- res = USECS_PER_JIFFY-1;
-
- return res;
-}
-
-#ifdef CONFIG_PM
-static unsigned long do_fast_pm_gettimeoffset(void)
-{
- unsigned long pc0;
- unsigned long offset;
-
- pc0 = au_readl(SYS_TOYREAD);
- au_sync();
- offset = pc0 - last_pc0;
- if (offset > 2*MATCH20_INC) {
- printk("huge offset %x, last_pc0 %x last_match20 %x pc0 %x\n",
- (unsigned)offset, (unsigned)last_pc0,
- (unsigned)last_match20, (unsigned)pc0);
- }
- offset = (unsigned long)((offset * 305) / 10);
- return offset;
-}
-#endif
-
-void au1xxx_timer_setup(struct irqaction *irq)
-{
- unsigned int est_freq;
- extern unsigned long (*do_gettimeoffset)(void);
- extern void au1k_wait(void);