xref: /linux/Documentation/hwmon/pwm-fan.rst (revision 87c9c16317882dd6dbbc07e349bc3223e14f3244)
1Kernel driver pwm-fan
2=====================
3
4This driver enables the use of a PWM module to drive a fan. It uses the
5generic PWM interface thus it is hardware independent. It can be used on
6many SoCs, as long as the SoC supplies a PWM line driver that exposes
7the generic PWM API.
8
9Author: Kamil Debski <k.debski@samsung.com>
10
11Description
12-----------
13
14The driver implements a simple interface for driving a fan connected to
15a PWM output. It uses the generic PWM interface, thus it can be used with
16a range of SoCs. The driver exposes the fan to the user space through
17the hwmon's sysfs interface.
18
19The fan rotation speed returned via the optional 'fan1_input' is extrapolated
20from the sampled interrupts from the tachometer signal within 1 second.
21