On Mon, Aug 22, 2016 at 1:55 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Saturday, August 20, 2016 11:35:35 AM CEST Martin Blumenstingl wrote: >> +- reg: The first register range should be the one of the DWMAC >> + controller. The second range is is for the Amlogic specific >> + configuration (for example the PRG_ETHERNET register range >> + on Meson8b and newer) >> > ... > >> +Example for GXBB: >> + ethmac: ethernet@c9410000 { >> + compatible = "amlogic,meson-gxbb-dwmac", "snps,dwmac"; >> + reg = <0x0 0xc9410000 0x0 0x10000>, >> + <0x0 0xc8834540 0x0 0x8>; >> > > The address "0xc8834540" suggests that this is part of a larger register > range that is used for various things, i.e. a "syscon" type of device. You are right, these are part of the cbus range (which is already defined in meson-gxbb.dtsi) > How about making this a syscon reference rather than a "reg" address? The first version of my patch ([0]) used syscon_regmap_lookup_by_phandle. Maybe I did it wrong (and I should have passed the cbus syscon-node instead of defining a new one just for the 2x32bit PRG_ETHERNET registers). I am perfectly fine with either way - however it seems that some other dwmac glue implementations are also using a second set of resources (that doesn't automatically make it "correct" though). Martin -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html