On Sunday 28 August 2016, Martin Blumenstingl wrote: > On Mon, Aug 22, 2016 at 5:25 PM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > > It really depends on the kind of SoC. Some may have a suboptimal > > binding, on some others there may be a distinct register area that > > just contains a few additional registers for the dwmac. > the dwmac PHY configuration registers (2x32bit) on the GXBB SoC are > part of the "periphs" region/module. This is already defined as > "simple-bus" in meson-gxbb.dtsi, see [0] > On Meson8b this is slightly different: there is no specific "periphs" > region - there the dwmac PHY configuration registers are directly > located in the cbus region at a slightly different offset than on the > GXBB SoCs. > > In the future we might need a third memory region because the latest > reference kernel contains some more PHY configuration registers on > newer SoCs (GXL = S905X). > > Please let me know if you're OK with the dts definition in it's > current state - or let me know how you would like to change it. > > PS: I will re-send the patches in a v3 in a few minutes because that > fixes a bug during module unload. I don't really see a good way to describe this hardware then. If it was only the first case, I'd suggest marking the periphs bus node as "compatible="simple-bus","syscon";" so you could have a reference to it, but that doesn't seem to work well in the second case, unless you can a separate DT node just for the PHY config registers there. With the third case, is there any logic at all behind the register map? Maybe someone else has a better idea for how to describe this. In general, we try to avoid overlapping "reg" properties, but I even see that the "periphs" node on gxbb has a "reg" property (is this intentional) that overlaps with the registers in its ranges, so adding another one won't make this worse than it already is. Arnd -- 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
