On Mon, 17 Jul 2017 11:41:01 +0530 Abhishek Sahu <absahu@xxxxxxxxxxxxxx> wrote: > >> > + > >> > +nand@79b0000 { > > > > nand-controller@xxxx { > > > > BTW, glad to see another driver moving to the new DT representation > > :-). > > > >> > + compatible = "qcom,qpic-nandc-v1.4.0"; > >> > + reg = <0x79b0000 0x1000>; > >> > + > >> > + clocks = <&gcc GCC_QPIC_CLK>, > >> > + <&gcc GCC_QPIC_AHB_CLK>; > >> > + clock-names = "core", "aon"; > >> > + > >> > + #address-cells = <1>; > >> > + #size-cells = <0>; > >> > + > >> > + nandcs@0 { > > > > nand@0 { > > > >> > + compatible = "qcom,nandcs"; > > > > Why do you need a compatible here? > It is the part of original driver. We can connect multiple > NAND devices in the same bus and qcom,nandcs is being used > for each connected NAND device. Each NAND device can use > different chip select, ecc strength etc which we can specify > under this sub node. Still don't understand why you need a compatible? Is this a memory bus where you can connect other kind of memories (parallel NORs, SRAMs, ...)? If that's not the case, then considering all subnodes of the nand-controller node containing a reg property as NAND devices is fine, you don't need this compatible = "nand,cs" (see sunxi-nand bindings [1]). If the bus is generic and can be attached non-NAND devices, I'd recommend looking at atmel's binding [2], because you're likely to have one instance of the NAND controller logic for all NAND devices connected on this bus. And more importantly, if the bus a generic, the node should not be named nand or nand-controller, and the compatible should not contain 'nandc' in it. [1]http://elixir.free-electrons.com/linux/latest/source/Documentation/devicetree/bindings/mtd/sunxi-nand.txt#L34 [2]http://elixir.free-electrons.com/linux/latest/source/Documentation/devicetree/bindings/mtd/atmel-nand.txt#L70 -- 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