Re: [PATCH v9 2/4] Documentation: Add documentation for APM X-Gene SoC SATA host controller DTS binding

[Loc Ho <lho@apm.com>]

Hi,

>>> >> >> +- clocks             : Reference to the clock entry.
>>> >> >> +- phys                       : PHY reference with parameter 0.
>>> >> >
>>> >> > The specific value of the phy-specifier shouldn't matter to this
>>> >> > binding. What should matter is what it logically corresponds to.
>>> >>
>>> >> I not quite following this. Are you suggest that I drop the value 0.
>>> >> In the binding, one needs to specify the mode of operation - 0 is for
>>> >> SATA. Can you explain more?
>>> >
>>> > The SATA device should not care what the argument for the PHY
>>> > device is. You could connect the same device to another PHY
>>> > that has a different set of arguments, which is the whole point
>>> > of abstracting it.
>>> >
>>>
>>> I understand what you wrote here. We should not have an argument from
>>> the host controller. Then my question is how should the PHY node
>>> indicates that it needs to be configured itself as an SATA PHY?
>>
>> The "phys" property should specify whatever the configuration of
>> the phy device is supposed to be. It's just not the business of
>> the sata driver or the sata binding to know what that configuration
>> is.
>>
>
> Here is what I have and I am trying to piece this together:
>
> phy1 {
>    #phy-cells = <0>;  /* No parameter as suggest by Mark */
> };
>
> sata1 {
>     :::
>     phys = <&phy1>;
> };
>
> What I don't get is how does one specify the mode
> (SATA/USB/SGMII/etc)? As another parameter in the phy1 node?
>

May be I misread what Mark mentioned. The binding documentation should
not specify the requirement of 0. And the binding of the dts should be
as is:

phy1 {
   #phy-cells = <1>;
};

sata1 {
   :::
   phys = <&phy1 0>;     where 0 indicates the mode of operation?
};

-Loc