- always initialize selector of voltage signaling standard.
Various versions of U-boot leaves voltage signaling standard settings
for PMUIO2 domain in different state. Always initialize it
into expected state.
- start the driver as early as possible, the IO domains should be
initialized before other drivers are attached.
- rename RK3399 register to its name founds in TRM.
This is the second part of fixes for serial port corruption observed after
DT 5.6 import.
Reviewed by: manu
MFC after: 1 week