tree 733eac5a54db173832434f10542b836621557b8e
parent 2ca66a74ee4874e121ac398fe83759df73e48065
author Matt Spinler <spinler@us.ibm.com> 1690914314 +0000
committer Andrew Geissler <geissonator@yahoo.com> 1691085442 +0000

meta-ibm: Use gpioset in reset-fan-watchdog

The reset-fan-watchdog service needs to toggle a GPIO in order to unlock
the fan watchdog circuit so fans can be controlled after the watchdog
has expired and locked them at high speed. This gets called on every
power on to bring the fans under control again in case the watchdog had
expired on the previous boot.

This was done previously using a custom application which used libgpiod
under the covers, which was written before gpioset was around.

Now that gpioset is available, just use it instead to toggle the GPIO so
there's less custom code we have to worry about maintaining.

The actual minimum timing requirement of the toggle is around 5ns, so
the 1us being used by all the config files meets that.

Tested:
Expired the watchdog by stopping the fan-watchdog service, then powered
off and back on and made sure the fans can still be controlled.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: Ibd36ff17e83b57d521364f0092dfa1f5abf34856