Hello Scott,


On 07/31/2014 12:28 AM, Scott Wood wrote:

On Wed, 2014-07-30 at 23:35 -0500, Emil Medve wrote:

quoted

Hello Scott,


On 07/30/2014 09:30 PM, Scott Wood wrote:

quoted

On Wed, 2014-07-30 at 16:52 -0500, Emil Medve wrote:

quoted

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+			mdio0: mdio <at> fc000 {
+			};

Why is the empty node needed?

For the label

For mdio-parent-bus, or is there some other dts layer that makes this
node non-empty?

'powerpc/corenet: Create the dts components for the DPAA FMan' -
http://patchwork.ozlabs.org/patch/370872

Why does this patch define the mdio0 label for mdio@e1120, but not
define a label for any other node?

Only MDIO controllers that are pinned out have these labels. Only pinned
out MDIO(s) are capable of controlling external PHY(s) via these board
level MDIO buses

Is there any reason to describe non-pinned-out MDIO controllers at all?

Yes. For the internal TBI PHY(s). Each MAC supporting SGMII has a TBI
PHY that is attached to the MDIO controller of the respective MAC

Is the lack of pinning out inherent to the silicon, or is it board
design/config?

It's a silicon level decision

Is the answer different for different MDIO controllers?

You mean non-FSL MDIO controllers? Dunno. All FSL SoC have the same MDIO
pin-out decision

I'm just curious why mdio@e1120 is labelled in a non-board dtsi while
others are labelled elsewhere.

Labels are relevant only in the context of 'powerpc/corenet: Add MDIO
bus muxing support to the board device tree(s)' -
http://patchwork.ozlabs.org/patch/370866. Most labels are created and
used in the board .dts file except b4qds.dtsi which is shared between
b4420qds.dts and b4860qds.dts


Cheers,