Dear Jean-Francois Moine,
On Thu, 5 Sep 2013 18:54:56 +0200, Jean-Francois Moine wrote:
The name of the kirwood audio driver has been changed from "kirkwood-i2s" to "mvebu-audio" by Russell King (http://www.spinics.net/lists/arm-kernel/msg264185.html). I have just used this name in the DT.
I don't care about the driver name: it can be changed whenever you want.
On the opposite, the DT compatible string becomes part of the kernel ABI, and therefore cannot be changed once it has been defined. This is why I worry about this one.
And the compatible string doesn't necessarily need to match the driver name.
Then, the second interrupt in Dove is not used in the driver. If it should, it would be present in the DTs of the dove boards only, so, actually, there is not need to have different compatibles.
Indeed the second interrupt is not used in the driver, but the binding still specifies that two interrupts have to be mentioned, which is incorrect for Kirkwood. The fact that on Kirkwood there is one interrupt, while Dove has two, is an indication that the IP block is not exactly the same. Should this error interrupt become useful in the driver, it should be done only for Dove, so it makes sense to have two different compatible strings.
Eventually, you are talking about some other mvebu SoCs. Before adding any new compatible, it would be nice to know if, for example, some changes are needed in the kirkwood/dove audio driver for the Armada 370...
So far, it looks like no changes should be needed. I'm sure this will bring you to the conclusion that 'mvebu-audio' is a good compatible string: it is not because while we know what Armada 370 looks today, we have absolutely no idea what the next Armada <something> will look like. Maybe it will use the same audio IP block, with just a few little variations.
Again, please read the mails from Rob Herring and Arnd Bergmann. It has been said numerous times that using the name of the oldest SoC that has the compatible IP block was the right choice for the compatible string.
Best regards,
Thomas