On Wed, Nov 06, 2024 at 07:59:05PM +0100, Marek Vasut wrote: > Delta AFC0612DB-F00 fan has to be set to at least 30% PWM duty cycle > to spin up from a stopped state, and can be afterward throttled down to > lower PWM duty cycle. Introduce support for operating such fans which > need to start at higher PWM duty cycle first and can slow down next. > > Introduce two new DT properties, "fan-stop-to-start-percent" and > "fan-stop-to-start-us". The former describes the minimum percent > of fan RPM at which it will surely spin up from stopped state. This > value can be found in the fan datasheet and can be converted to PWM > duty cycle easily. The "fan-stop-to-start-us" describes the minimum > time in microseconds for which the fan has to be set to stopped state > start RPM for the fan to surely spin up. > > Adjust the PWM setting code such that if the PWM duty cycle is below > the minimum duty cycle needed by the fan to spin up from stopped state, > then first set the PWM duty cycle to the minimum duty cycle needed > by the fan to spin up from stopped state, then wait the time necessary > for the fan to spin up from stopped state, and finally set the PWM duty > cycle to the one desired by user. > > Signed-off-by: Marek Vasut <marex@xxxxxxx> Applied. Thanks, Guenter
