On Tue, Sep 24, 2013 at 3:03 AM, Stephen Warren <swarren@xxxxxxxxxxxxx> wrote: > On 09/23/2013 05:50 AM, Laurent Pinchart wrote: >> On Monday 23 September 2013 08:18:52 Prabhakar Lad wrote: >>> On Fri, Sep 20, 2013 at 3:22 PM, Sylwester Nawrocki wrote: >>>> On 09/20/2013 10:11 AM, Prabhakar Lad wrote: >>>>> OK I will, just send out a fix up patch which fixes the mismatch between >>>>> names for the rc-cycle, and later send out a patch which removes the >>>>> platform data usage for next release with proper DT bindings. >>>> >>>> I think the binding need to be fully corrected now, I just meant to not >>>> touch the board file, i.e. leave non-dt support unchanged. >>> >>> Ok >>> >>>>> I'm OK with making regulator properties as optional, But still it would >>>>> change the meaning of what DT is, we know that the VDD/VDD_IO .. etc >>>>> pins are required properties (but still making them as optional) :-( >>>>> >>>>> I think there might several devices where this situation may arise so >>>>> just thinking of a alternative solution. >>>>> >>>>> say we have property 'software-regulator' which takes true/false(0/1) >>>>> If set to true we make the regulators as required property or else we >>>>> assume it is handled and ignore it ? >>>> >>>> I don't think this is a good idea. You would have to add a similar >>>> platform data flag for non-dt, it doesn't sound right. I can see two >>>> options here: >>>> >>>> 1. Make the regulator properties mandatory and, e.g. define a fixed >>>> voltage GPIO regulator in DT with an empty 'gpio' property. Then >>>> pass a phandle to that regulator in the adv7343 *-supply properties. >>>> For non-dt similarly a fixed voltage regulator(s) and voltage >>>> supplies would need to be defined in the board files. >>>> >>>> 2. Make the properties optional and use (devm_)regulator_get_optional() >>>> calls in the driver (a recently added function). I must admit I don't >>>> fully understand description of this function, it currently looks >>>> pretty much same as (devm_)regulator_get(). Thus the driver would >>>> need to be handling regulator supplies only when non ERR_PTR() is >>>> returned from regulator_get_optional() and otherwise assume a non >>>> critical error. There is already quite a few example occurrences of >>>> regulator_get_optional() usage. >>> >>> Thanks for pointing it I'll choose option 2 and post the patch. >> >> Isn't regulator_get_optional() intended for devices that can have supplies >> unconnected in normal use ? > > I believe so, yes. > Agreed >> The ADV7343 supplies are mandatory from a hardware >> point of view, so I think we should use regulator_get(). Otherwise the driver >> won't be able to tell the difference between a regulator that isn't present >> yet (for instance because the regulator device/driver hasn't been probed yet), >> which should result in deferred probing, and an always-on regulator that has >> been left out. > > So I think you want to make the supply properties mandatory in DT (since > some form of supply is mandatory in HW), yet make the driver support > broken DTs which don't have those properties, by error-checking the > return value from regulator_get(). You might want to put a note into DT > saying that a previous version of the binding didn't require those > supply properties, so they may be missing from older DTs. OK, I'll fix it and repost the patch. Regards, --Prabhakar -- 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
