1Kernel driver pc87427 2===================== 3 4Supported chips: 5 * National Semiconductor PC87427 6 Prefix: 'pc87427' 7 Addresses scanned: none, address read from Super I/O config space 8 Datasheet: No longer available 9 10Author: Jean Delvare <khali@linux-fr.org> 11 12Thanks to Amir Habibi at Candelis for setting up a test system, and to 13Michael Kress for testing several iterations of this driver. 14 15 16Description 17----------- 18 19The National Semiconductor Super I/O chip includes complete hardware 20monitoring capabilities. It can monitor up to 18 voltages, 8 fans and 216 temperature sensors. Only the fans are supported at the moment. 22 23This chip also has fan controlling features, which are not yet supported 24by this driver either. 25 26The driver assumes that no more than one chip is present, which seems 27reasonable. 28 29 30Fan Monitoring 31-------------- 32 33Fan rotation speeds are reported as 14-bit values from a gated clock 34signal. Speeds down to 83 RPM can be measured. 35 36An alarm is triggered if the rotation speed drops below a programmable 37limit. Another alarm is triggered if the speed is too low to to be measured 38(including stalled or missing fan). 39