diff options
Diffstat (limited to 'Documentation/hwmon/pc87427')
| -rw-r--r-- | Documentation/hwmon/pc87427 | 31 |
1 files changed, 26 insertions, 5 deletions
diff --git a/Documentation/hwmon/pc87427 b/Documentation/hwmon/pc87427 index d1ebbe510f3..c313eb66e08 100644 --- a/Documentation/hwmon/pc87427 +++ b/Documentation/hwmon/pc87427 @@ -7,7 +7,7 @@ Supported chips: Addresses scanned: none, address read from Super I/O config space Datasheet: No longer available -Author: Jean Delvare <khali@linux-fr.org> +Author: Jean Delvare <jdelvare@suse.de> Thanks to Amir Habibi at Candelis for setting up a test system, and to Michael Kress for testing several iterations of this driver. @@ -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 -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. @@ -34,5 +35,25 @@ Fan rotation speeds are reported as 14-bit values from a gated clock 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 to be measured +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. |