freebsd-skq/sys/dev/mk48txx
Marius Strobl 6b1c98e2be - Some of the upper bits of the time related (seconds, minutes, etc.)
registers are control bits or depending on the model contain additional
  time bits with a different meaning than the lower ones. In order to
  only read the desired time bits and not change the upper bits on write
  use appropriate masks in the gettime and settime function respectively.
  Due to the polarity of the stop oscillator bit and the fact that the
  century bits aren't used on sparc64 not masking them didn't cause
  problems so far.
- Fix two off-by-one errors in the handling of the day of week. The
  genclock code represents the dow as 0 - 6 with 0 being Sunday but the
  mk48txx use 1 - 7 with 1 being Sunday. In the settime function when
  writing the dow to the clock the range wasn't adjusted accordingly but
  the clock apparently played along nicely otherwise the second bug in
  the gettime function which mapped 1 - 7 to 0 - 6 but with 0 meaning
  Saturday would have been triggered. Fixing these makes the date being
  stored in the same format Sun/Solaris uses and cures the "Invalid time
  in real time clock. Check and reset the date immediately!" when the
  date was set under Solaris prior to booting FreeBSD/sparc64. [1]
  Looking at other clock drivers/code e.g. FreeBSD/alpha the former "bug",
  i.e. storing the dow as 0 - 6 even when the clock uses 1 - 7, seems to
  be common but might be on purpose for compatibility when multi-booting
  with other OS which do the same. So it might make sense to add a flag
  to handle the dow off-by-one for use of this driver on platforms other
  than sparc64.
- Check the state of the battery on mk48txx that support this in the
  attach function.
- Add a note that use of the century bit should be implemented but isn't
  required at the moment because it isn't used on sparc64.

Problem noted by:	joerg [1]
MT5 candidate.
2004-09-19 21:38:11 +00:00
..
mk48txx.c - Some of the upper bits of the time related (seconds, minutes, etc.) 2004-09-19 21:38:11 +00:00
mk48txxreg.h - Some of the upper bits of the time related (seconds, minutes, etc.) 2004-09-19 21:38:11 +00:00