[PATCH V5 0/3] hwmon: pwm-fan: Add RPM support

[Stefan Wahren]

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 V5:
- address Guenter's and Robin's comments:
  - use of_property_read_u32 to get pulses-per-revolution
  - call platform_get_irq ealier to avoid glitches on the regulator
  - simplify pwm_fan_attrs_visible

Changes in V4:
- remove copy & paste artifact in dt-binding example
- switch to u64 for rpm calculation
- drop overflow handling and init atomic
- handle 0 not as valid irq
- reduce range of pulses_per_revolution
- handle probe defer of platform_get_irq
- delete timer properly in bail-out path

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          |  21 +++-
 Documentation/hwmon/pwm-fan                        |   3 +
 drivers/hwmon/pwm-fan.c                            | 107 ++++++++++++++++++++-
 3 files changed, 126 insertions(+), 5 deletions(-)

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2.7.4