Re: [PATCH] [v7] net: emac: emac gigabit ethernet controller driver

[Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On 08/17/2016 03:32 PM, Timur Tabi wrote:
> Timur Tabi wrote:
>>>
>>> Nothing prevents you from detailing in ACPI or DT sub-components of a
>>> larger HW block, if there is such a desire, but just make it in a way
>>> that it looks like what would be done for e.g: separate discrete parts,
>>> only the parenting of nodes would change.
>>
>> So instead of just having a single property, instead create a child node
>> just for the SGMII phy, with its own compatible string and various other
>> properties (like interrupt and base register)?  That's not a bad idea.
> 
> I need help getting this to work.
> 
>     emac0: ethernet@38800000 {
>         compatible = "qcom,qdf2432-emac";
>         reg-names = "base", "csr";
>                 reg = <0x0 0x38800000 0x0 0x10000 >,
>                         <0x0 0x38816000 0x0 0x1000>,
>                         <0x0 0x3881C000 0x0 0x4000>;
>         interrupts = <0 0x100 0 0 0x104 0>;
>         interrupt-names = "core0", "sgmii";
> 
>         sgmii-handle = <&emac_sgmii>;
>         phy-handle = <&phy0>;
> 
>         #address-cells = <1>;
>         #size-cells = <0>;
>         phy0: ethernet-phy@4 {
>             reg = <4>;
>         };
>     };
> 
>     emac_sgmii: ethernet-phy@410400 {
>         compatible = "qcom,qdf2432-emac-phy";
>         reg = <0x0 0x00410400 0x0 0x100>;
>         interrupts = <0 0x104 0>;
>     };
> 

Is this register range relative to the emac0 node here, or is this
really a separate node, within the same adress space as your emac0 node?

> When my driver probes, the platform_device object points to the emac0
> node, as always.
> 
> How do I parse the emac_sgmii node?  How do I get functions like
> platform_get_resource() to work?  How do I create a new platform_device
> object that points to the emac_sgmii node?

Answer largely depends on whether your device is really located outside
of the emac, if it located outside, then a platform device matching the
compatible string would get you what you want. If the emac_sgmii block
is a sub-block within the EMAC, then a few things need fixing:

- your emac_sgmii node should be a sub-node of the emac node, not a sibling
- the emac0 node should have a "ranges" property that indicates how to
translate the sub-nodes' "reg" property based on the base register
address of the emac0 block
- you would have to call of_platform_populate from the EMAC driver to
ensure that the emac_sgmii child node and therefore platform device gets
created


-- 
Florian
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