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Diffstat (limited to 'Documentation/hwmon/kfan.rst')
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diff --git a/Documentation/hwmon/kfan.rst b/Documentation/hwmon/kfan.rst new file mode 100644 index 000000000000..ce02dddfb4b8 --- /dev/null +++ b/Documentation/hwmon/kfan.rst @@ -0,0 +1,39 @@ +.. 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) +====================== ==== =================================================== |