S32G PFE MDIO use cases

[SherlockInSpace]

I'm looking to use the PFE MDIO with the SJA1105 switch.

In my use case:

• The PFE2 MDIO bus is connected to a set of 4 AR8035 PHYs
• The MDIO bus is able to see the AR8035 PHYs
• The PHYs are connected to the SJA1105 ports via MII
• PFE2 is connected to the SJA1105 via SGMII using the SerDes subsystem
• I'm using v1.0.0 RTM of the PFE driver

I'm trying to get the SJA1105 to use the PFE MDIO bus to configure the PHYs correctly.

I've got a few questions for my use case.

1. Is this setup/configuration possible?
2. How can I use the phytool to configure the PHYs on the PFE MDIO bus?
3. Is it possible to use the PFE MDIO bus without instantiating the entire PFE subsystem?

[MayanksPatel]

Hi @SherlockInSpace,

Sorry for the delay.

Your use-case to use PFE MDIO through SJA1105 without instantiating PFE Subsystem is not possible because SJA1105 is directly connected to PFE_EMAC2 and to use PFE MDIO you need to configure PFE. you can't directly use ethernet Phy AR8035.

Hope this helps.

[SherlockInSpace]

To confirm, is the PFE MDIO interface using a separate memory space from the PFE subsystem itself (i.e. accessible by the SoC directly)? Or does the full PFE subsystem need to be running and configured correctly?

What I'm trying to understand is whether the existing, or a completely new, driver can be used that interfaces only with the MDIO interface of the PFE subsystem, without having to instantiate the entire subsystem itself. We only need certain features at this point.

[MayanksPatel]

Hi @SherlockInSpace,

Theoretically, your setup will be supported but the software doesn't support this. pfeng_mdio_register() is called in the PFE driver. this function call will instantiate the PFE system.

Hope this helps.

Thanks,

[MayanksPatel]

Hi @SherlockInSpace,

Sorry for the delay.

I am working on this case and will update you as soon as possible.

Thanks,

Mayank s Patel

[MayanksPatel]

Hi @SherlockInSpace,

Sorry for the delay.

As per the BSP33.0 User Manual,

There is no support of MDIO to Phy in u-boot via SJA1105 but in kernel support is enabled but not through SJA1105.

Please refer to the attached screenshot for your reference.

Thanks,

Mayank s Patel

[SherlockInSpace]

I understand that, but what I don't understand is whether or not my use case is supported.

Can the SJA1105 use the PFE MDIO bus to control the AR8035 PHYs without instantiating the entire PFE subsystem? The screenshots you shared with me don't seem to answer my question.

[SherlockInSpace]

Is there anyone at NXP that is knowledgeable about this topic?

[SherlockInSpace]

Bump. Is there anyone at NXP that can assist?