Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wirel...

[mv-sheeva.git] / Documentation / hwmon / pc87427

diff --git a/Documentation/hwmon/pc87427 b/Documentation/hwmon/pc87427
index db5cc1227a83949a50146cbe01dd887c8610bcea..8fdd08c9e48b5ceac48b100ee4cedbdf78fcc242 100644 (file)
--- a/Documentation/hwmon/pc87427
+++ b/Documentation/hwmon/pc87427
@@ -18,10 +18,11 @@ Description
 
 The National Semiconductor Super I/O chip includes complete hardware
 monitoring capabilities. It can monitor up to 18 voltages, 8 fans and
 
 The National Semiconductor Super I/O chip includes complete hardware
 monitoring capabilities. It can monitor up to 18 voltages, 8 fans and

-6 temperature sensors. Only the fans are supported at the moment.
+6 temperature sensors. Only the fans and temperatures are supported at
+the moment, voltages aren't.

 
 

-This chip also has fan controlling features, which are not yet supported
-by this driver either.
+This chip also has fan controlling features (up to 4 PWM outputs),
+which are partly supported by this driver.

 
 The driver assumes that no more than one chip is present, which seems
 reasonable.
 
 The driver assumes that no more than one chip is present, which seems
 reasonable.


@@ -36,3 +37,23 @@ signal. Speeds down to 83 RPM can be measured.
 An alarm is triggered if the rotation speed drops below a programmable
 limit. Another alarm is triggered if the speed is too low to be measured
 (including stalled or missing fan).
 An alarm is triggered if the rotation speed drops below a programmable
 limit. Another alarm is triggered if the speed is too low to be measured
 (including stalled or missing fan).

+
+
+Fan Speed Control
+-----------------
+
+Fan speed can be controlled by PWM outputs. There are 4 possible modes:
+always off, always on, manual and automatic. The latter isn't supported
+by the driver: you can only return to that mode if it was the original
+setting, and the configuration interface is missing.
+
+
+Temperature Monitoring
+----------------------
+
+The PC87427 relies on external sensors (following the SensorPath
+standard), so the resolution and range depend on the type of sensor
+connected. The integer part can be 8-bit or 9-bit, and can be signed or
+not. I couldn't find a way to figure out the external sensor data
+temperature format, so user-space adjustment (typically by a factor 2)
+may be required.