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

From: Timur Tabi
Date: Fri Apr 15 2016 - 13:24:08 EST


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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