This adds a short description for the new RPM support of the pwm-fan driver. Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx> --- Documentation/hwmon/pwm-fan | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/Documentation/hwmon/pwm-fan b/Documentation/hwmon/pwm-fan index 18529d2..a1ba34c 100644 --- a/Documentation/hwmon/pwm-fan +++ b/Documentation/hwmon/pwm-fan @@ -15,3 +15,7 @@ The driver implements a simple interface for driving a fan connected to a PWM output. It uses the generic PWM interface, thus it can be used with a range of SoCs. The driver exposes the fan to the user space through the hwmon's sysfs interface. + +The measured fan rotation speed returned via 'fan1_input' is derived +from the sampled interrupts from the tachometer signal by assuming +a 2 pulse-per-revolution fan. -- 2.7.4
