These changes support extended mode operation for the ADT7461 which will
allow temperature readings from -64..191 degC instead of the current
limited range of 0..127 degC. I decided to split up the changes so
that the first patch doesn't affect functionality, but just makes
preparations needed to make the second patch easier to follow.
This is the second version of the patch, which addresses the feedback
from Jean Delvare. Changes from v1:
* Force inline the *_from_reg() functions
* Convert "? :" code to if/then
* Don't force enabling of extended mode -- just use it if
the chip is already in that mode
* Use unsigned integers for adt7461 conversion functions
* Clarified up comments as requested
* Fix off-by-one errors in extended mode conversion functions
I verified that patch 1/2 does not change the functionality by
comparing the output of both the macros and the new static functions
over a large range of values. For the extended mode conversions, I
verified the following register->temperature conversions (and vice
versa) to make sure all the corner cases are right:
Temperature 1-byte 2-byte
-------- ------ ------
-65000 0x00 0x0000
-64500 0x00 0x0000
-64000 0x00 0x0000
-63750 0x00 0x0040
-63500 0x01 0x0080
-63250 0x01 0x00c0
-63000 0x01 0x0100
-62750 0x01 0x0140
-62500 0x02 0x0180
-62250 0x02 0x01c0
-62000 0x02 0x0200
-250 0x40 0x3fc0
0 0x40 0x4000
250 0x40 0x4040
500 0x41 0x4080
750 0x41 0x40c0
1000 0x41 0x4100
1250 0x41 0x4140
1500 0x42 0x4180
1750 0x42 0x41c0
2000 0x42 0x4200
190750 0xff 0xfec0
191000 0xff 0xff00
191250 0xff 0xff40
191500 0xff 0xff80
191750 0xff 0xffc0
192000 0xff 0xffc0
--
Nate Case <ncase at xes-inc.com>
