1.. SPDX-License-Identifier: GPL-2.0 2 3Kernel driver kfan 4================== 5 6Supported chips: 7 8 * KEBA fan controller (IP core in FPGA) 9 10 Prefix: 'kfan' 11 12Authors: 13 14 Gerhard Engleder <eg@keba.com> 15 Petar Bojanic <boja@keba.com> 16 17Description 18----------- 19 20The KEBA fan controller is an IP core for FPGAs, which monitors the health 21and controls the speed of a fan. The fan is typically used to cool the CPU 22and the whole device. E.g., the CP500 FPGA includes this IP core to monitor 23and control the fan of PLCs and the corresponding cp500 driver creates an 24auxiliary device for the kfan driver. 25 26This driver provides information about the fan health to user space. 27The user space shall be informed if the fan is removed or blocked. 28Additionally, the speed in RPM is reported for fans with tacho signal. 29 30For fan control PWM is supported. For PWM 255 equals 100%. None-regulable 31fans can be turned on with PWM 255 and turned off with PWM 0. 32 33====================== ==== =================================================== 34Attribute R/W Contents 35====================== ==== =================================================== 36fan1_fault R Fan fault 37fan1_input R Fan tachometer input (in RPM) 38pwm1 RW Fan target duty cycle (0..255) 39====================== ==== =================================================== 40