[PATCH] ARM: imx: imx8mn-ddr4-evk: Add ethernet support

[Marek Vasut]

On 3/2/21 9:21 AM, Michael Nazzareno Trimarchi wrote:
> Hi Marek
> 
> On Tue, Mar 2, 2021 at 9:13 AM Marek Vasut <marex at denx.de> wrote:
>>
>> On 3/2/21 8:53 AM, Jagan Teki wrote:
>>> On Sat, Feb 27, 2021 at 6:21 PM Marek Vasut <marex at denx.de> wrote:
>>>>
>>>> On 2/27/21 8:54 AM, Jagan Teki wrote:
>>>>> Hi Marek,
>>>>>
>>>>> On Sat, Feb 27, 2021 at 3:44 AM Marek Vasut <marex at denx.de> wrote:
>>>>>>
>>>>>> Add support for ethernet on the imx8mn-ddr4-evk.
>>>>>>
>>>>>> Signed-off-by: Marek Vasut <marex at denx.de>
>>>>>> Cc: Fabio Estevam <festevam at gmail.com>
>>>>>> Cc: Peng Fan <peng.fan at nxp.com>
>>>>>> Cc: Stefano Babic <sbabic at denx.de>
>>>>>> ---
>>>>>>     arch/arm/dts/imx8mn-evk.dtsi            |  1 +
>>>>>>     board/freescale/imx8mn_evk/imx8mn_evk.c | 41 +++++++++++++++++++++++--
>>>>>>     configs/imx8mn_ddr4_evk_defconfig       |  8 +++++
>>>>>>     3 files changed, 47 insertions(+), 3 deletions(-)
>>>>>>
>>>>>> diff --git a/arch/arm/dts/imx8mn-evk.dtsi b/arch/arm/dts/imx8mn-evk.dtsi
>>>>>> index 76d042a4cf0..416fadb22b1 100644
>>>>>> --- a/arch/arm/dts/imx8mn-evk.dtsi
>>>>>> +++ b/arch/arm/dts/imx8mn-evk.dtsi
>>>>>> @@ -53,6 +53,7 @@
>>>>>>            pinctrl-0 = <&pinctrl_fec1>;
>>>>>>            phy-mode = "rgmii-id";
>>>>>>            phy-handle = <&ethphy0>;
>>>>>> +       phy-reset-gpios = <&gpio4 22 GPIO_ACTIVE_LOW>;
>>>>>
>>>>> I believe this is phy reset-gpio to be part of mdio child node. any
>>>>> idea why it added in fec1 node?
>>>>
>>>> Try $ git grep phy-reset drivers/net/ , that should clarify it all.
>>>> In short, FEC in U-Boot still uses legacy bindings.
>>>
>>> True. I think it's better to add this property on -u-boot.dtsi which
>>> helps to maintain Linux bindings.
>>
>> The reset GPIO is not specific to U-Boot in any way, so no.
>> Instead, the Linux DT bindings should be updated too, but that's a
>> separate topic.
> 
> Deprecated optional properties:
>          To avoid these, create a phy node according to phy.txt in the same
>          directory, and point the fec's "phy-handle" property to it. Then use
>          the phy's reset binding, again described by phy.txt.
> - phy-reset-gpios : Should specify the gpio for phy reset
> - phy-reset-duration : Reset duration in milliseconds.  Should present
>    only if property "phy-reset-gpios" is available.  Missing the property
>    will have the duration be 1 millisecond.  Numbers greater than 1000 are
> 
> Jagan refer maybe that property is deprecated

See above, U-Boot does not support the per-PHY reset bindings with FEC.
However, the PHY reset GPIO binding is not U-Boot specific, so it should 
not be hidden in -u-boot.dtsi .