On Tuesday, October 16, 2018, Rob Herring wrote: > > +Optional properties: > > + - gpio-controller > > + Include this in order to enable GPIO functionality. When included, > both > > + gpio_cells and gpio_ranges are then required. > > + - #gpio-cells > > + Must be 2 > > + - gpio-ranges > > + Expresses the total number GPIO ports/pins in this SoC > > Are these really optional? I guess in theory a board could use no GPIOs, > but that seems unlikely. They are 'optional' in the sense that if you don't include them in the DT, the driver still loads (just without any GPIO, but pinctrl still works). So, I was just documenting that fact. If you think I should just move these to required, let me know an I'm fine with that. (as in, DT documents HW, not software) > > +Sub-nodes > > +--------- > > + > > +The child nodes of the pin controller node describe a pin multiplexing > > +function or a GPIO controller alternatively. > > But the parent is already a GPIO controller. This needs to be fully > defined. Now that I read this, I think my wording was off (I was borrowing text for other files). How about this: The child nodes of the pin controller designate pins to be used for specific peripheral functions or as GPIO. Chris
