DTC: appending / concatenating to a path reference

DTC: appending / concatenating to a path reference

[Brian Norris]

Hi DT folks,

In taking a look at the /chosen/stdout-path (and
/chosen/linux,stdout-path) properties described in ePAPR and in
Documentation/devicetree/bindings/chosen.txt, I see that one can use a
path name reference, followed by a colon (':') and an options string to
add options to a particular console. e.g.:

/ {
	serial@f000 {
		...
	};

	chosen {
		stdout-path = "/serial@f000:115200";
	};
}

When there are no options to append, DTS syntax can easily handle this
for you with the '&' operator, to automatically generate a path name:

/ {
	uart: serial@f000 {
		...
	};

	chosen {
		stdout-path = &uart;
	};
};

However, it appears the device tree compiler provides no syntax for
concatenating anything to a path. I see there was an RFC patch set for
more general expression support [1], though it doesn't handle everything
I'd like. For instance, with the proposed syntax, I could imagine doing
this:

/ {
	uart: serial@f000 {
		...
	};

	chosen {
		stdout-path = &uart + ":115200";
	};
};

though that patch set doesn't handle this.

Thoughts? What's the status with DTS language extensions like [1]?

Regards,
Brian

[1] http://thread.gmane.org/gmane.comp.devicetree.compiler/3/
--
To unsubscribe from this list: send the line "unsubscribe devicetree-compiler" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html