On 2/18/19 11:18 PM, Harald Geyer wrote: > Marek Vasut writes: >> So what about >> >> gpios-states : Initial state of GPIO pins in "gpios" array, set on >> system start and retained until consumer changes the state. 0: LOW, 1: >> HIGH. Default is LOW if nothing else is specified. > > No. "retained until consumer changes the state" is promising more then > is guaranteed. > > From the explanations provided by Mark it is clear that this property > is an artifact of the implementation in linux. I think we should document > is as such. How about: > > gpios-states : On operating systems, that don't support reading back gpio > values in output mode (most notably linux), this array > provides the state of GPIO pins set when requesting them > from the gpio controller.
That's good. > Systems, that are capable of > preserving state when requesting the lines, are free to > ignore this property. Are they ? I think there are systems which depend on preconfiguring the GPIO according to this property. > 0: LOW, 1: HIGH. Default is LOW if > nothing else is specified. > > HTH, > Harald > -- Best regards, Marek Vasut