[PATCH net-next v2 1/2] net: dsa: mt7530-mdio: read PHY address of switch from device tree

Arınç ÜNAL arinc.unal at arinc9.com
Tue Apr 16 01:32:49 PDT 2024


On 15/04/2024 18:30, Florian Fainelli wrote:
> 
> 
> On 4/13/2024 11:07 PM, Arınç ÜNAL via B4 Relay wrote:
>> From: Arınç ÜNAL <arinc.unal at arinc9.com>
>>
>> Read the PHY address the switch listens on from the reg property of the
>> switch node on the device tree. This change brings support for MT7530
>> switches on boards with such bootstrapping configuration where the switch
>> listens on a different PHY address than the hardcoded PHY address on the
>> driver, 31.
>>
>> As described on the "MT7621 Programming Guide v0.4" document, the MT7530
>> switch and its PHYs can be configured to listen on the range of 7-12,
>> 15-20, 23-28, and 31 and 0-4 PHY addresses.
>>
>> There are operations where the switch PHY registers are used. For the PHY
>> address of the control PHY, transform the MT753X_CTRL_PHY_ADDR constant
>> into a macro and use it. The PHY address for the control PHY is 0 when the
>> switch listens on 31. In any other case, it is one greater than the PHY
>> address the switch listens on.
>>
>> Reviewed-by: Daniel Golle <daniel at makrotopia.org>
>> Tested-by: Daniel Golle <daniel at makrotopia.org>
>> Signed-off-by: Arınç ÜNAL <arinc.unal at arinc9.com>
> 
> Reviewed-by: Florian Fainelli <florian.fainelli at broadcom.com>
> 
> I would go a step further and name phy_addr switch_mdio_addr, or something along those lines to clearly denote this is not a per-port PHY address neither a proper PHY device, but we've already had a similar discussion before about spelling this out clearly as a "pseudo PHY"....

I am fine with calling the switch operating on an MDIO bus a psuedo-PHY.
But I don't believe this grants making up names on our own instead of using
the name described in IEEE Std 802.3-2022. The switch listens on a PHY
address on the MDIO bus. The description for the phy_addr member of the
mt753x_info structure clearly explains that so I don't see a reason to
change the variable name.

Arınç



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