On Thu, Jan 31, 2013 at 10:22 AM, Inki Dae <inki.dae at samsung.com> wrote: > 2013/1/31 Stephen Warren <swarren at wwwdotorg.org>: >> On 01/30/2013 06:16 PM, Inki Dae wrote: >>> 2013/1/30 Sylwester Nawrocki <sylvester.nawrocki at gmail.com>: >>>> Hi, >>>> >>>> >>>> On 01/08/2013 11:56 PM, Stephen Warren wrote: >>>>> >>>>> On 01/08/2013 01:16 PM, Sean Paul wrote: >>>>>> >>>>>> Add a property to the hdmi node so we can specify the HDMI version in >>>>>> the device tree instead of just defaulting to v1.4 with the existence of >>>>>> the dt node. >>>>> >>>>> >>>>> I guess this seems OK to me if required, although I'd certainly like to >>>>> see someone familiar with the Exynos HW confirm whether this should be >>>>> driven purely by DT compatible value for the HDMI IP block instead though. >>>> >>>> >>>> I think the supported HDMI standard is something that could well be derived >>>> from the compatible property. The IP supporting v1.3 and v1.4 will be >>>> significantly different, so this would anyway already need to be reflected >>>> in the compatible property. The only issue I see here is that people tend >>>> to make the compatible string overly generic, so it is hardly usable for >>>> anything but matching an IP with its driver. For instance for exynos5 we >>>> have now (Documentation/devicetree/bindings/drm/exynos/hdmi.txt): >>>> >>>> compatible = "samsung,exynos5-hdmi"; >>>> >>>> For Exynos4 series there were already some patches proposed [1], but I >>>> believe >>>> this isn't a clean solution. Instead of things like: >>>> >>>> compatible = "samsung,exynos4-hdmi13"; >>>> compatible = "samsung,exynos4-hdmi14"; >>>> >>>> I would much more like to see the SoC version embedded in the compatible >>>> string, e.g. >>>> >>> >>> Hi Sylwester. long time no see. >>> >>> I think that if we use the SoC version embedded in the compatible >>> string then each driver shoud aware of the ip version to the SoC to >> >> The driver only needs to be aware of one SoC version for each IP version. >> > > I know that device tree describes hw information and the information > includes ip version also. So shouldn't the driver aware of the ip > version itself and should the driver only aware of it through device > tree? So I thought using the version property is proper way. >
I want to second Sylwester's proposal. Compatibility information should be carried in compatible string. 'version' property is diluting its purpose. With this implementation, all compatible strings : "exynos-hdmi", "exynos4-hdmi", "exynos4x12-hdmi", "exynos5-hdmi" ... have same relevance. IMO, it make sense with compatible strings specifying the first Soc with same IP version: compatible = "samsung,exynos4210-hdmi"; compatible = "samsung,exynos4212-hdmi"; compatible = "samsung,exynos-hdmi-1.3" and compatible = "samsung,exynos-hdmi-1.4" will also do the needful. While representing hdmi version information we should consider the possibility of intermediate releases like 1.3ab, 1.4a etc. regards, Rahul Sharma. > >> So with Sylwester's proposal: >> >>>> compatible = "samsung,exynos4210-hdmi"; /* among others it carries an >>>> information this IP supports >>>> HDMI v1.3 */ >>>> >>>> compatible = "samsung,exynos4212-hdmi"; /* HDMI v1.4, IIRC */ >> >> The driver woulud only ever have to know about those two compatible >> values (unless further incompatible HW revisions exist); any other SoC >> would be listed as being compatible with one of those two strings (but >> in addition to the specific value for the specific SoC, e.g. compatible >> = "samsung,exynox5xxx-hdmi", "samsung,exynos4212-hdmi"). >> >>> use version specific feature so I think it's better to use it without >>> the SoC version embedded in the compatible string like this, >>> compatible = "samsung,exynos4-hdmi" >>> version = "0x104" or "0x103" >> >> That would be quite non-typical. >> >>> With this, all each driver to do is to check version property and set >>> version specific feature properly. And we have some dtsi file to can >>> be used commonly. >>> >>> For example, >>> exynos4.dtsi : have all Exynos4 series SoCs common properties and also >>> use common compatible string. >>> exynos4412.dtsi, exynos4212.dtsi and so on: have Exynos42xx specific >>> properties. So the hdmi version string could be used here as "version >>> = "0x104" or "0x103" >>> exynos4412-board.dts: have board specific properties. >>> >>> compatible = "samsung,exynos5-hdmi" is reasonable to me. >>> any opinions? >> >> _______________________________________________ >> dri-devel mailing list >> dri-devel at lists.freedesktop.org >> http://lists.freedesktop.org/mailman/listinfo/dri-devel > _______________________________________________ > dri-devel mailing list > dri-devel at lists.freedesktop.org > http://lists.freedesktop.org/mailman/listinfo/dri-devel
