Hi Rob & Laurent :) On 04/26/2018 12:05 AM, Laurent Pinchart wrote: > Hi Rob, > > On Wednesday, 25 April 2018 20:11:23 EEST Rob Herring wrote: >> On Wed, Apr 25, 2018 at 04:17:25PM +0300, Laurent Pinchart wrote: >>> On Wednesday, 25 April 2018 15:20:04 EEST Philippe CORNU wrote: >>>> On 04/25/2018 11:01 AM, Laurent Pinchart wrote: >>>>> On Wednesday, 25 April 2018 10:53:13 EEST Philippe Cornu wrote: >>>>>> Add optional power supplies using the description found in >>>>>> "SiI9022A/SiI9024A HDMI Transmitter Data Sheet (August 2016)". >>>>>> >>>>>> There is a single 1v2 supply voltage named vcc12 from which cvcc12 >>>>>> (digital core) and avcc12 (TMDS analog) are derived because according >>>>>> to this data sheet: >>>>>> "cvcc12 and avcc12 can be derived from the same power source" >>>>> >>>>> Shouldn't the power supplies be mandatory, as explained by Mark in >>>>> https://lists.freedesktop.org/archives/dri-devel/2018-April/172400.html >>>>> ? >>>> >>>> Laurent, >>>> Many thanks Laurent for your comment, I understood the merge of the two >>>> 1v2 power supplies but missed the "mandatory" part... maybe because this >>>> patch (with optional power supplies) already got the reviewed-by from >>>> Rob, I thought the discussion thread you pointed out was applicable >>>> "only" to totally new driver documentation. >>>> >>>> So, on my side, as a "new user" of sii902x IC, no problem to put these >>>> power supplies as mandatory instead of optional properties but I would >>>> like to be sure this is applicable to both old and new bindings doc : ) >>> >>> We obviously need to retain backward compatibility, so on the driver side >>> you need to treat those power supplies as optional. From a DT bindings >>> point of view, however, I think they should be mandatory for new DT. >> >> We don't really have a way to describe these 3 conditions (required for >> all, optional for all, and required for new). So generally we make >> additions optional. The exception sometimes is if we update all the dts >> files. > > Can't we just make it mandatory in the bindings, as long as we treat it as > optional in drivers ? > How to progress on this patch? Do you have any suggestions? Many thanks for your help, Philippe :-) >>>> Rob, >>>> could you please confirm these power supply properties should be >>>> "mandatory"? if yes, should we then modify other optional properties like >>>> the reset-gpios too in the future? >>> >>> The GPIOs properties are different in my opinion, as there's no >>> requirement to connect for instance the reset pin to a GPIO controllable >>> by the SoC. The pin could be hardwired to VCC, or connected to a system >>> reset that is automatically managed without SoC intervention. The power >>> supplies, however, are mandatory, in the sense that the chip will not work >>> if you leave the power supplies unconnected. >> >> DT only needs to describe what matters to s/w. If a regulator is >> fixed and you don't need to know its voltage (or other read-only >> parameters), then there's not much point in putting it in DT. >> >> I'd probably base this more at a platform level and you either use >> regulator binding or you don't. It's perfectly valid that you want to do >> things like regulator setup, pin ctrl and muxing setup, etc. all in >> firmware and the OS doesn't touch any of that. >> >> That's all a big can of worms which we shouldn't solve on this 2 line >> change. I think this change is fine as-is, so: >> >> Reviewed-by: Rob Herring <robh@xxxxxxxxxx> > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
