| Kernel driver pc87427 | |
| ===================== | |
| Supported chips: | |
| * National Semiconductor PC87427 | |
| Prefix: 'pc87427' | |
| Addresses scanned: none, address read from Super I/O config space | |
| Datasheet: No longer available | |
| Author: Jean Delvare <khali@linux-fr.org> | |
| Thanks to Amir Habibi at Candelis for setting up a test system, and to | |
| Michael Kress for testing several iterations of this driver. | |
| 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. | |
| This chip also has fan controlling features, which are not yet supported | |
| by this driver either. | |
| The driver assumes that no more than one chip is present, which seems | |
| reasonable. | |
| Fan Monitoring | |
| -------------- | |
| 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 | |
| (including stalled or missing fan). |