Kernel driver kfan

Supported chips:

• KEBA fan controller (IP core in FPGA)

  Prefix: ‘kfan’

Authors:

Gerhard Engleder <eg@keba.com> Petar Bojanic <boja@keba.com>

Description

The KEBA fan controller is an IP core for FPGAs, which monitors the health and controls the speed of a fan. The fan is typically used to cool the CPU and the whole device. E.g., the CP500 FPGA includes this IP core to monitor and control the fan of PLCs and the corresponding cp500 driver creates an auxiliary device for the kfan driver.

This driver provides information about the fan health to user space. The user space shall be informed if the fan is removed or blocked. Additionally, the speed in RPM is reported for fans with tacho signal.

For fan control PWM is supported. For PWM 255 equals 100%. None-regulable fans can be turned on with PWM 255 and turned off with PWM 0.

Attribute	R/W	Contents
fan1_fault	R	Fan fault
fan1_input	R	Fan tachometer input (in RPM)
pwm1	RW	Fan target duty cycle (0..255)