xref: /linux/Documentation/hwmon/qnap-mcu-hwmon.rst (revision e814f3fd16acfb7f9966773953de8f740a1e3202)
1.. SPDX-License-Identifier: GPL-2.0-or-later
2
3Kernel driver qnap-mcu-hwmon
4============================
5
6This driver enables the use of the hardware monitoring and fan control
7of the MCU used on some QNAP network attached storage devices.
8
9Author: Heiko Stuebner <heiko@sntech.de>
10
11Description
12-----------
13
14The driver implements a simple interface for driving the fan controlled by
15setting its PWM output value and exposes the fan rpm and case-temperature
16to user space through hwmon's sysfs interface.
17
18The fan rotation speed returned via the optional 'fan1_input' is calculated
19inside the MCU device.
20
21The driver provides the following sensor accesses in sysfs:
22
23=============== ======= =======================================================
24fan1_input	ro	fan tachometer speed in RPM
25pwm1		rw	relative speed (0-255), 255=max. speed.
26temp1_input	ro	Measured temperature in millicelsius
27=============== ======= =======================================================
28