[V3,0/3] hwmon: pwm-fan: Add RPM support

Message

Stefan Wahren March 22, 2019, 8:24 a.m. UTC

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(-)