Cut and paste this URL to share the unmodified register and value:
https://regviz.com/r/Silicon Labs/EFR32BG22C222F352GN32/CMU_NS/DPLLREFCLKCTRL#0x0
CLKSEL=DISABLED
No Description
Clock Select
0 (DISABLED): DPLLREFCLK is not clocked
1 (HFXO): HFXO is clocking DPLLREFCLK
2 (LFXO): LFXO is clocking DPLLREFCLK
3 (CLKIN0): CLKIN0 is clocking DPLLREFCLK
https://github.com/cmsis-svd/cmsis-svd-data