Re: [PATCH 07/10] ARM: dts: sun7i: cubietruck: Enable the GMAC

[Florian Fainelli]

2013/12/6 Chen-Yu Tsai <wens@xxxxxxxx>:
> On Sat, Dec 7, 2013 at 5:09 AM, Florian Fainelli <f.fainelli@xxxxxxxxx> wrote:
>> 2013/12/6 Chen-Yu Tsai <wens@xxxxxxxx>:
>>> The CubieTruck uses the GMAC with an RGMII phy.
>>>
>>> Signed-off-by: Chen-Yu Tsai <wens@xxxxxxxx>
>>> ---
>>>  arch/arm/boot/dts/sun7i-a20-cubietruck.dts | 8 ++++++++
>>>  1 file changed, 8 insertions(+)
>>>
>>> diff --git a/arch/arm/boot/dts/sun7i-a20-cubietruck.dts b/arch/arm/boot/dts/sun7i-a20-cubietruck.dts
>>> index 8a1009d..af212a2 100644
>>> --- a/arch/arm/boot/dts/sun7i-a20-cubietruck.dts
>>> +++ b/arch/arm/boot/dts/sun7i-a20-cubietruck.dts
>>> @@ -33,6 +33,14 @@
>>>                         pinctrl-0 = <&uart0_pins_a>;
>>>                         status = "okay";
>>>                 };
>>> +
>>> +               gmac: ethernet@01c50000 {
>>> +                       pinctrl-names = "default";
>>> +                       pinctrl-0 = <&gmac_pins_rgmii>;
>>> +                       snps,phy-addr = <1>;
>>
>> What is this snps,phy-addr property? Why is not a standard device tree
>> node for an Ethernet PHY node used?
>
> This property is implemented by stmmac and documented in the DT
> bindings. stmmac has not been updated to use Ethernet PHY nodes.

This driver property should be removed and deprecated since there is
an ePAPR standardized Ethernet PHY node. What I am worried here is the
loss of information, the standard Ethernet DT node allows to specify
much more information (clause, maximum speed, compatible string
etc...).

>
> Removing this property will not affect the function of the driver.
> The driver probes its MDIO bus and selects the lowest available
> address if not specified.

So if this is just giving the driver a hint on where to  probe for a
PHY on the MDIO bus, then let's drop it and use the standard DT node
no?

>
>>> +                       phy-mode = "rgmii";
>>
>> Especially since you use the relatively standard "phy-mode" property here?
>
> Used as specified in stmmac DT bindings.

That one is kind of okay because of_get_phy_mode() knows about it,
even though ePAPR states this should be "phy-connection-type", so I am
okay with keeping that one because current practice and helpers are
here.
-- 
Florian
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