tree e166c109e4d9da60aa1f6590c302042fff716729
parent 41bf870e6db130c6e467c70b6da96398066b8be7
author Henrik Rydberg <rydberg@euromail.se> 1342423090 +0200
committer Guenter Roeck <linux@roeck-us.net> 1342932525 -0700

hwmon: (applesmc) Allow negative temperature values

There are many userland reports of sensors with unreasonably small and
large temperatures. There seem to be several reasons for this:

Firstly, the major sensor type (sp78) is actually a signed number.
This explains why some sensors show very small or large values - they
are in fact all small, but of different sign.

Secondly, the other sensor type (1-hex) is not properly understood; it
may be that it is not a temperature after all.

Thirdly, some sensors are differential in nature, showing changes over
time rather than absolute numbers.  This explains why those values are
small and of varying sign.

This patch interprets the sp78 type as signed short, but keeps the
original scaling. For other types, -EINVAL is returned, since the
nature of those sensors is unknown.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>