Contrary to the gpio-fan the pwm-fan driver isn't easy to setup with pwmconfig/fancontrol because of the missing hwmon sysfs entry for actual revolutions per minute. This series adds this feature. Changes in V3: - rename property interrupt-ratio to pulses-per-revolution to avoid confusion with interrupt binding - handle error case pulses-per-revolution = 0 - bail out properly in case we are unable to request the irq Changes in V2: - address Guenter's comments: - improve description of interrupts - use atomic_t to avoid races of the pulse counter - measure sample time to make rpm more reliable under load - make sysfs entry fan1_input conditional - add dt-property to define interrupts per fan revolution - example for fan with RPM support Stefan Wahren (3): dt-bindings: hwmon: Add tachometer interrupt to pwm-fan Documentation: pwm-fan: Add description for RPM support hwmon: pwm-fan: Add RPM support via external interrupt .../devicetree/bindings/hwmon/pwm-fan.txt | 22 ++++- Documentation/hwmon/pwm-fan | 3 + drivers/hwmon/pwm-fan.c | 100 ++++++++++++++++++++- 3 files changed, 123 insertions(+), 2 deletions(-) -- 2.7.4