On 02/08/2013 04:16 PM, Sylwester Nawrocki wrote: > On 02/07/2013 12:40 AM, Stephen Warren wrote: >>> diff --git >>> a/Documentation/devicetree/bindings/media/soc/samsung-fimc.txt >>> b/Documentation/devicetree/bindings/media/soc/samsung-fimc.txt >> >>> +Samsung S5P/EXYNOS SoC Camera Subsystem (FIMC) >>> +---------------------------------------------- ... >>> +For every fimc node a numbered alias should be present in the >>> aliases node. >>> +Aliases are of the form fimc<n>, where<n> is an integer (0...N) >>> specifying >>> +the IP's instance index. >> >> Why? Isn't it up to the DT author whether they care if each fimc node is >> assigned a specific identification v.s. whether identification is >> assigned automatically? > > There are at least three different kinds of IPs that come in multiple > instances in an SoC. To activate data links between them each instance > needs to be clearly identified. There are also differences between > instances of same device. Hence it's important these aliases don't have > random values. > > Some more details about the SoC can be found at [1]. The aliases are > also already used in the Exynos5 GScaler bindings [2] in a similar way. Hmmm. I'd expect explicit DT properties to represent the instance-specific "configuration", or even different compatible values. Relying on the alias ID seems rather indirect; what if in e.g. Exynos6/... the mapping from instance/alias ID to feature set changes. With explicit DT properties, that'd just be a .dts change, whereas by requiring alias IDs now, you'd need a driver change to support this. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
