+ uint32_t timeout;
+
+ /* Disable watchdog */
+ WDT_MR = BV(WDT_WDDIS);
+
+ /* Set wait states for flash access, needed for higher CPU clock rates */
+ EEFC0_FMR = EEFC_FMR_FWS(3);
+#ifdef EEFC1_FMR
+ EEFC1_FMR = EEFC_FMR_FWS(3);
+#endif
+
+ // Initialize main oscillator
+ if (!(CKGR_MOR & BV(CKGR_MOR_MOSCSEL)))
+ {
+ CKGR_MOR = CKGR_MOR_KEY(0x37) | CKGR_MOR_MOSCXTST(0x8)
+ | BV(CKGR_MOR_MOSCRCEN) | BV(CKGR_MOR_MOSCXTEN);
+ timeout = CLOCK_TIMEOUT;
+ while (!(PMC_SR & BV(PMC_SR_MOSCXTS)) && --timeout);
+ }
+
+ // Switch to external oscillator
+ CKGR_MOR = CKGR_MOR_KEY(0x37) | CKGR_MOR_MOSCXTST(0x8)
+ | BV(CKGR_MOR_MOSCRCEN) | BV(CKGR_MOR_MOSCXTEN) | BV(CKGR_MOR_MOSCSEL);
+ timeout = CLOCK_TIMEOUT;
+ while (!(PMC_SR & BV(PMC_SR_MOSCXTS)) && --timeout);
+
+ // Initialize and enable PLL clock
+ CKGR_PLLR = evaluate_pll() | BV(CKGR_PLLR_STUCKTO1) | CKGR_PLLR_PLLCOUNT(0x2);
+ timeout = CLOCK_TIMEOUT;
+ while (!(PMC_SR & BV(PMC_SR_LOCK)) && --timeout);
+
+ PMC_MCKR = PMC_MCKR_CSS_MAIN_CLK;
+ timeout = CLOCK_TIMEOUT;
+ while (!(PMC_SR & BV(PMC_SR_MCKRDY)) && --timeout);
+
+ PMC_MCKR = PMC_MCKR_CSS_PLL_CLK;
+ timeout = CLOCK_TIMEOUT;
+ while (!(PMC_SR & BV(PMC_SR_MCKRDY)) && --timeout);
+
+ /* Enable clock on PIO for inputs */
+ // TODO: move this in gpio_init() for better power management?
+ pmc_periphEnable(PIOA_ID);
+ pmc_periphEnable(PIOB_ID);
+ pmc_periphEnable(PIOC_ID);
+#ifdef PIOF_ID
+ pmc_periphEnable(PIOD_ID);
+ pmc_periphEnable(PIOE_ID);
+ pmc_periphEnable(PIOF_ID);
+#endif