On 08/08/2012 07:30 AM, Rob Herring wrote: > On 08/08/2012 04:52 AM, Leela Krishna Amudala wrote: >> Hello All, >> >> I came across that to set power to an LCD, few panels require a pull >> up/pull down operation on single GPIO line >> and few panels need some gpio line setting sequence with some delay in >> between. ... >> Putting the sequence in dts file like below for an LCD which requires >> gpio sequence >> lcd-reset-gpio = <&gpx1 5 1 3 0>, (3 - for pull up) >> <&gpx1 5 1 1 0>, (1 - for pull down) >> <&gpx1 5 1 3 0>; (3 - for pull up) >> delay = x; >> >> and only one gpio entry in the case of LCD which doesn't require gpio >> sequence setting >> lcd-reset-gpio = <&gpx1 5 1 3 0>, (3 - pull up) >> >> The 4 arguments in the above handle denotes >> >> <[phandle of the gpio controller node] >> [pin number within the gpio controller] >> [mux function] >> [pull up/down] >> [drive strength]>
Mux function, pull-up/down and drive-strength should be handled by the pinctrl subsystem, and associated DT bindings. I suppose the proposal in the "runtime interpreted power sequences" thread could be extended to have an action for activating a particular pinctrl state too. _______________________________________________ devicetree-discuss mailing list [email protected] https://lists.ozlabs.org/listinfo/devicetree-discuss
