On 08/27/2013 12:40 AM, boris brezillon wrote: > On 27/08/2013 05:57, Stephen Warren wrote: >> On 08/26/2013 11:17 AM, boris brezillon wrote: >>> On 26/08/2013 18:53, Stephen Warren wrote: >>>> On 08/24/2013 03:37 PM, Boris BREZILLON wrote: >>>>> Add support for generic pin configuration to pinctrl-at91 driver. >>>>> diff --git >>>>> a/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt >>>>> b/Documentation/devicetree/bindings/pinctrl/atmel,at91-pinctrl.txt >>>>> Required properties for iomux controller: >>>>> -- compatible: "atmel,at91rm9200-pinctrl" >>>>> +- compatible: "atmel,at91rm9200-pinctrl" or >>>>> "atmel,at91sam9x5-pinctrl". >>>> You seem to also be adding a second chip name to the list here, >>>> which is >>>> more than the patch subject/description imply you're doing... >>> This is an update of the documentation: >>> "atmel,at91sam9x5-pinctrl" compatible is already used in the pinctrl >>> driver but the documention >>> was not updated. >>> >>> But I agree, this should not be part of this series. >>> >>>>> + Add "generic-pinconf" to the compatible string list to use the >>>>> generic pin >>>>> + configuration syntax. >>>> "generic-pinconf" is too generic of a compatible value for this binding >>>> to define. >>>> >>>> Instead, I think you want to either: >>>> >>>> a) >>>> >>>> Use compatible="atmel,at91rm9200-pinctrl" for the old binding, >>>> use compatible="atmel,at91rm9200-pinctrl-generic" for the new binding >>>> >>>> or: >>>> >>>> b) >>>> >>>> Define Boolean property atmel,generic-pinconf (perhaps a better name >>>> could be chosen?). If it's not present, parse the node assuming the old >>>> binding. If it is present, parse the node assuming the new binding. >>>> >>> Okay. >>> >>> I thought this property string could be generic as it may concern other >>> drivers too >>> (in order to keep compatibility with old dt ABI and add support the >>> generic pinconf binding). >>> >>> Anyway, I prefer the first proposition. >>> >>> pinctrl single driver is already using these names: >>> >>> |compatible = "pinctrl-single" for non generic pinconf binding >>> ||compatible = "pinconf-single" ||for generic pinconf binding| >>> >>> So I think we should use something similar: >>> >>> |compatible = "atmel,at91xx-pinctrl" for non generic pinconf binding >>> ||compatible = "|||atmel,at91xx-|pinconf" ||for generic pinconf binding| >>> >>> What do you think ? >> Hmmm. It is a little odd to switch out the compatible value and invent a >> new binding for the same HW. Isn't it possible to define both sets of >> properties in the binding, and have drivers look for either? >> > > Do you mean something like: > > atmel,pins = <xxx>; /* current dt binding */ > atmel,generic-pins = <yyy>; /* new dt binding */ > > If that's what you had in mind, it will be a little bit tricky to > handle, because AFAIK the pinconf_ops > callbacks do not give me any element I could use to deduce the type of > pinconf (generic or > native). > This implies I have to know early during the probe process which kind of > binding is in use. > > Please tell me if I missed some key points, and this can be easily done. It's probably most compatible to keep all the existing properties, and just add new properties for new features. -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
