On Thu, Sep 17, 2020 at 02:03:46AM -0700, Trent Piepho wrote: > On Mon, Sep 14, 2020 at 3:44 AM Drew Fustini <drew@xxxxxxxxxxxxxxx> wrote: > > > > + > > +When #pinctrl-cells = 2, then setting a pin for a device could be done with: > > + > > + pinctrl-single,pins = <0xdc 0x30 0x07>; > > + > > +Where 0x30 is the pin configuration value and 0x07 is the pin mux mode value. > > +See the device example and static board pins example below for more information. > > Pin configuration and mux mode don't mean anything in pinctrl-single. > On another machine, mux mode might not be programmed this way or even > exist. Or the location of bits would probably be different, and this > would seem to imply the 0x07 would get shifted to the correct location > for where the pin mux setting was on that machine's pinctrl registers. > > It seems like it would be better to explain the values are ORed together. I descirbed it as seoerate values as I did not want to prescribe what the pcs driver would do with those values. But, yes, it is a just an OR operation, so I could change the language to reflect tat. > What is the purpose of this change anyway? It seems like in the end > it just does what it did before. The data is now split into two cells > in the device tree, but why? These changes were a result of desire to seperate pinconf and pinmux. Tony raised the idea in a thread at the end of May [1]. Tony wrote: > Only slightly related, but we should really eventually move omaps to use > #pinctrl-cells = <2> (or 3) instead of 1, and pass the pinconf seprately > from the mux mode. We already treat them separately with the new > AM33XX_PADCONF macro, so we'd only have to change one SoC at a time to > use updated #pinctrl-cells. But I think pinctrl-single might need some > changes before we can do that. thanks, drew [1] https://lore.kernel.org/linux-omap/20200527165122.GL37466@xxxxxxxxxxx/
