-/*
- * Hah! We'll see if this works (switching from usecs to nsecs).
- */
-static unsigned long tmu_timer_get_frequency(void)
-{
- u32 freq;
- struct timespec ts1, ts2;
- unsigned long diff_nsec;
- unsigned long factor;
-
- /* Setup the timer: We don't want to generate interrupts, just
- * have it count down at its natural rate.
- */
- ctrl_outb(0, TMU_TSTR);
-#if !defined(CONFIG_CPU_SUBTYPE_SH7300) && !defined(CONFIG_CPU_SUBTYPE_SH7760)
- ctrl_outb(TMU_TOCR_INIT, TMU_TOCR);
-#endif
- ctrl_outw(TMU0_TCR_CALIB, TMU0_TCR);
- ctrl_outl(0xffffffff, TMU0_TCOR);
- ctrl_outl(0xffffffff, TMU0_TCNT);
-
- rtc_get_time(&ts2);
-
- do {
- rtc_get_time(&ts1);
- } while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec);
-
- /* actually start the timer */
- ctrl_outb(TMU_TSTR_INIT, TMU_TSTR);
-
- do {
- rtc_get_time(&ts2);
- } while (ts1.tv_nsec == ts2.tv_nsec && ts1.tv_sec == ts2.tv_sec);
-
- freq = 0xffffffff - ctrl_inl(TMU0_TCNT);
- if (ts2.tv_nsec < ts1.tv_nsec) {
- ts2.tv_nsec += 1000000000;
- ts2.tv_sec--;
- }
-
- diff_nsec = (ts2.tv_sec - ts1.tv_sec) * 1000000000 + (ts2.tv_nsec - ts1.tv_nsec);
-
- /* this should work well if the RTC has a precision of n Hz, where
- * n is an integer. I don't think we have to worry about the other
- * cases. */
- factor = (1000000000 + diff_nsec/2) / diff_nsec;
-
- if (factor * diff_nsec > 1100000000 ||
- factor * diff_nsec < 900000000)
- panic("weird RTC (diff_nsec %ld)", diff_nsec);
-
- return freq * factor;
-}
-