| .. SPDX-License-Identifier: GPL-2.0 |
| |
| 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) |
| ====================== ==== =================================================== |
