Subject: Re: [PATCH 1/2] [v4] net: emac: emac gigabit ethernet controller driver

From: Timur Tabi <[email-masked]>
Date: Fri, 15 Apr 2016 12:23:54 -0500

Rob Herring wrote:
> You may only care about the size, but the binding has to handle the
> more complex case. Here's an example
>
> <0x0 0x2 0x0 0x1 0x0>
>
> dma address 0 (cell 0) maps to cpu (parent) address 0x2_00000000 (cell
> 1-2) and the range/size is 4G (cell 3-4).
>
> If you have the same base address, then use the same address. The core
> will calculate the mask based on the size. IIRC, we also handle ~0 as
> a special case to support 4G for #size-cell=1.

So the first thing I noticed is that Gilad had this:

	reg =   <0xfeb20000 0x10000>,
		<0xfeb36000 0x1000>,
		<0xfeb3c000 0x4000>,
		<0xfeb38000 0x400>;
	#address-cells = <0>;

Shouldn't address-cells have been 1 instead?

Ok, let me see if I get this right:

32-bit:

soc {
	#address-cells = <1>;
	#size-cells = <1>;

	emac0: qcom,emac@feb20000 {
		compatible = "qcom,fsm9900-emac";
		#address-cells = <1>;
		#size-cells = <1>;
		reg-names = "base", "csr", "ptp", "sgmii";
		reg =   <0xfeb20000 0x10000>,
			<0xfeb36000 0x1000>,
			<0xfeb3c000 0x4000>,
			<0xfeb38000 0x400>;
		dma-ranges = <0 0 0xffffffff>;
		interrupt-parent = <&emac0>;

64-bit

soc {
	#address-cells = <2>;
	#size-cells = <2>;

	emac0: qcom,emac@feb20000 {
		compatible = "qcom,fsm9900-emac";
		#address-cells = <2>;
		#size-cells = <2>;
		reg-names = "base", "csr", "ptp", "sgmii";
		reg =   <0 0xfeb20000 0 0x10000>,
			<0 0xfeb36000 0 0x1000>,
			<0 0xfeb3c000 0 0x4000>,
			<0 0xfeb38000 0 0x400>;
		dma-ranges = <0 0 0 0 0xffffffff 0xffffffff>;

This seems inelegant, though.

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