[PATCH] net: dwc_eth_qos: add support of device tree configuration for reset delay

[Patrick DELAUNAY]

Hi,

On 4/15/21 8:08 AM, Ramon Fried wrote:
> On Thu, Apr 15, 2021 at 4:41 AM Ramon Fried <rfried.dev at gmail.com> wrote:
>> On Wed, Apr 14, 2021 at 5:36 PM Marek Vasut <marex at denx.de> wrote:
>>> On 4/14/21 4:07 PM, Patrick DELAUNAY wrote:
>>>> Hi,
>>> Hi,
>>>
>>>> On 4/9/21 2:22 PM, Marek Vasut wrote:
>>>>> On 4/9/21 10:00 AM, Patrick Delaunay wrote:
>>>>>> The gpio reset assert/deassert delay are today harcoded in U-Boot driver
>>>>>> but the value should be read from DT.
>>>>>>
>>>>>> STM32 use the generic binding defined in linux:
>>>>>> Documentation/devicetree/bindings/net/ethernet-phy.yaml
>>>>>>
>>>>>>     reset-gpios:
>>>>>>       maxItems: 1
>>>>>>       description:
>>>>>>         The GPIO phandle and specifier for the PHY reset signal.
>>>>>>
>>>>>>     reset-assert-us:
>>>>>>       description:
>>>>>>         Delay after the reset was asserted in microseconds. If this
>>>>>>         property is missing the delay will be skipped.
>>>>>>
>>>>>>     reset-deassert-us:
>>>>>>       description:
>>>>>>         Delay after the reset was deasserted in microseconds. If
>>>>>>         this property is missing the delay will be skipped.
>>>>>>
>>>>>> See also U-Boot: doc/device-tree-bindings/net/phy.txt
>>>>> Since this is a PHY property, shouldn't that be handled in
>>>>> drivers/net/phy/ instead of MAC driver ?
>>>>
>>>> I was my first idea but I don't found found the correct location in phy
>>>> (driver or uclass)
>>>>
>>>> to manage these generic property and the generic property "reset-gpios"
>>>> was already
>>>>
>>>> managed in eth driver, so I continue to patch the driver.
>>>>
>>>>
>>>> But I come back to this idea after your remark....
>>>>
>>>> => in linux these property are managed in
>>>>
>>>>       drivers/net/mdio/of_mdio.c::of_mdiobus_phy_device_register
>>>>
>>>>           parse DT node and add info in mdio
>>>>
>>>>       drivers/net/phy/mdio_device.c::mdio_device_reset
>>>>
>>>>           called in  mdio_probe / mdio_remove
>>>>
>>>>
>>>> In my first search, I don't found the same level in the U-Boot drivers
>>>> in drivers/net/phy/
>>> Note that this is MDIO-wide PHY reset (e.g. you can have single reset
>>> line connected to multiple PHYs on single MDIO bus), this is not
>>> PHY-specific reset.
>>>
>>>> but I miss the uclass defined in drivers/net/eth-phy-uclass.c
>>>>
>>>>
>>>> Finally I think I need to manage the generic binding property
>>>>
>>>> (reset-gpios, reset-assert-us, reset-deassert-us) directly  in
>>>>
>>>> => drivers/net/mdio-uclass
>>>>
>>>>
>>>> The GPIO RESET will be managed in mdio  ops: pre_probe/ post_remove
>>>>
>>>> as it is done in linux
>>>>
>>>> warning: today post_remove ops don't exit in u-class.
>>>>
>>>>
>>>> Do you think it is the correct location ?
>>> For single-PHY reset, the correct location is in drivers/net/phy/ somewhere.
>>>
>>>> Do you think it should be a new serie (migrate the eqos property in mdio)
>>>>
>>>> after this eqos is accepted
>>>>
>>>> or I shoudl sent a new serie to replace this serie.
>>> I'll leave that decision to Ramon/Joe.
>> Joe, I'll leave this to you.
> You know what, let's go with the new series, please migrate it to the net/phy.
> Thanks,
> Ramon


I am preparing V2 with DT parsing in drivers/net/eth-phy-uclass.c

with CONFIG_DM_ETH_PHY enabled for stm32 variant of dwc_eth_qos driver.

Regards

Patrick