+#if defined(CONFIG_SAMA5D2)
+ /* Enable a measurement of the external oscillator */
+ tmp = readl(&pmc->mcfr);
+ tmp |= AT91_PMC_MCFR_CCSS_XTAL_OSC;
+ tmp |= AT91_PMC_MCFR_RCMEAS;
+ writel(tmp, &pmc->mcfr);
+
+ while (!(readl(&pmc->mcfr) & AT91_PMC_MCFR_MAINRDY))
+ ;
+
+ if (!(readl(&pmc->mcfr) & AT91_PMC_MCFR_MAINF_MASK))
+ hang();
+#endif
+