On Mon, Mar 19, 2018 at 11:29 AM, Sylwester Nawrocki s.nawrocki@samsung.com wrote:
On 03/18/2018 04:35 PM, Krzysztof Kozlowski wrote:
Compatible for XU4 audio is not being used. Instead the board uses the same compatible as XU3. The devices are now just compatible so they should use the same value. Mark "hardkernel,odroid-xu4-audio" as being deprecated so in this future could be removed to limit useless properties.
It doesn't feel right to obsolete the "hardkernel,odroid-xu4-audio" compatible, there is significant difference between XU3 and XU4 - there is no audio CODEC on XU4, this board only supports audio over HDMI interface. XU4 could be compatible with XU3, but not the other way around. It just happens we have other DT properties that help to handle such HW design difference.
The compatible does not describe physical differences. It does not mean that devices are the same. In this case they are just coming from the same family and they operate the same, from the bindings perspective.
The XU4 binding is not being used. Adding a compatible which is not used in the moment of adding is a proof that this compatible is not needed. It is just a duplicate. There is no point of adding duplicates.
Moreover, only XU4 is still in production and should be in few more years [1], others are obsoleted now.
It is not a problem. Whether device is manufactured or not, does not reflect what bindings we are using. Deprecated XU4 compatible does not mean that XU4 itself is deprecated. Just this compatible should not be used for new DTS.
So I think we should keep at least these 2 compatible strings:
- "hardkernel,odroid-xu3-audio" - for boards with audio CODEC,
- "hardkernel,odroid-xu4-audio" - for boards without audio CODEC, supporting only HDMI interface.
Yeah, and then we inflate this list into X, X2, U3, HC1 and all others which are the same. And then we should add XU3-lite (it is different device). This goes to some nonsense. Compatible is not for each device but for family even though there are differences between specific devices.
Best regards, Krzysztof