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The KEBA fan controller is found in the system FPGA of KEBA PLC devices. It detects if the fan is removed or blocked. For fans with tacho signal the monitoring of the speed of the fan is supported. It also supports to regulate the speed of fans with PWM input. The auxiliary device for this driver is instantiated by the cp500 misc driver. Signed-off-by: Gerhard Engleder <eg@keba.com> Link: https://lore.kernel.org/r/20250425194823.54664-1-gerhard@engleder-embedded.com [groeck: Added various missing "break;" statements] Signed-off-by: Guenter Roeck <linux@roeck-us.net>
40 lines
1.3 KiB
ReStructuredText
40 lines
1.3 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
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Kernel driver kfan
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==================
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Supported chips:
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* KEBA fan controller (IP core in FPGA)
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Prefix: 'kfan'
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Authors:
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Gerhard Engleder <eg@keba.com>
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Petar Bojanic <boja@keba.com>
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Description
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-----------
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The KEBA fan controller is an IP core for FPGAs, which monitors the health
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and controls the speed of a fan. The fan is typically used to cool the CPU
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and the whole device. E.g., the CP500 FPGA includes this IP core to monitor
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and control the fan of PLCs and the corresponding cp500 driver creates an
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auxiliary device for the kfan driver.
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This driver provides information about the fan health to user space.
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The user space shall be informed if the fan is removed or blocked.
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Additionally, the speed in RPM is reported for fans with tacho signal.
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For fan control PWM is supported. For PWM 255 equals 100%. None-regulable
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fans can be turned on with PWM 255 and turned off with PWM 0.
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====================== ==== ===================================================
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Attribute R/W Contents
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====================== ==== ===================================================
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fan1_fault R Fan fault
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fan1_input R Fan tachometer input (in RPM)
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pwm1 RW Fan target duty cycle (0..255)
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====================== ==== ===================================================
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