[PATCH v3 5/5] ARM: vexpress: DT-based support for CoreTiles Express A5x2 and A9x4

Pawel Moll pawel.moll at arm.com
Mon Dec 5 12:24:40 EST 2011


On Thu, 2011-12-01 at 12:21 +0000, Dave Martin wrote:
> That will work, but we should make it clear that this option does not
> provide board support all by itself, maybe:
> 
> "Provides common dependencies for VE platforms based on Cortex-A5 or
> Cortex-A9 processors.  In order to build a working kernel, you must also
> enable one or more core tile support options."

Actually, the longer I think about it the more it seems that this code
doesn't support a particular tile, but rather a particular processor...
After all _exactly_ the same code will work with any SMM based on FPGA
Logic Tile (V2F-2XV6), even if it was very different from the coretile,
eg. A9 with RS1 memory map. In such case making it compatible with
V2P-CA9 would be logically wrong...

I have an idea of spinning the compatible values again to get something
like that:

compatible = "arm,vexpress-v2p-ca5s", "arm,vexpress-cortex_a5";
compatible = "arm,vexpress-v2p-ca9", "arm,vexpress-cortex_a9";
compatible = "arm,vexpress-v2p-ca15", "arm,vexpress-cortex_a15";

and the board code would simply have:

static const char *dt_ca5_ca9_dt_match[] __initdata = {
	"arm,vexpress-cortex_a5",
	"arm,vexpress-cortex_a9",
	NULL,
};

I've already tried that (adding tree for A15 tile as well) and it
actually simplifies a lot of things. I'll clean the patches, test them
and post tomorrow. Of course if anyone thinks it's a bad idea I'm happy
to get back to where we were last week.

Cheers!

Paweł





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