- Add function to parse RDH FIS for use in implementing AT_READREG.
- Correct and clean up some structure definitions.
- Sprinkle a bit of const.
- Remove dependency on <dev/ic/wdcreg.h>, WDCTL_4BIT doesn't seem
to be specified by any recent ATA standard, and it seems to make
no difference in practice.
- Stop using WDSD_IBM, these bits have been obsolete since before SATA.
siisata:
- Implement AT_READREG.
- Reap now-unneeded <dev/ic/wdcreg.h>.
- Whitespace and slight debug code cleanup.
- Some possibly-uncessary code reordering.
ahcisata:
- Implement AT_READREG.
- Reap now-unneeded <dev/ic/wdcreg.h>.