AM62A7-Q1: rgmii rx_delay and tx_delay

Hi Expert,

customer have try to add this in dts, but it will not work, so I am seeking for help. Where can customer adjust this parameter? and how to modify it?

BR,

BIAO 

Hi Biao,

Based off of the existing DTS files for SK AM62A7 (https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/tree/arch/arm64/boot/dts/ti/k3-am62a7-sk.dts?h=ti-linux-6.1.y), the rx internal delay is typically configured in the &cpsw2g_mdio node. 

As an additional resource the DTS bindings can also be found in https://software-dl.ti.com/processor-sdk-linux/esd/AM62AX/latest/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW3g.html#device-tree-bindings 

Since the "phy-mode" is set to "rgmii-rxid" in the snapshot of your DTS, only rx-internal-delay can be configured for the PHY to enable RX delay.

-Daolin

The rx internal delay parameter in the PHY dts provided by you in the SDK was parsed and set in the PHY driver program, but we switched to Mavell's PHY, which cannot set this delay. Therefore, it needs to be set on the SOC side, that is, in the Mac controller driver program

Hi Schuyler,

I want double check with BU team, do we have test DP83TG720S-Q1? Does DP83TG720S-Q1 support change the rx delay? Because DP83867 don't have the Q1 version, so customer want change the phy to DP83TG720S-Q1.

BR,

Biao 

Hi,

I can forward the request to the Ethernet team as this is a different BU from mine. A quick look at the data sheet for the DP83TG720S-Q1shows it supporting the RX internal delay. But I will ask the Ethernet team to comment.

Best Regards,

Schuyler

Hi Biao,

Yes, you can adjust the RGMII TX and RX delays through registers on the DP83TG720 in registers 0x602 and 0x430 as mentioned in the datasheet.

Best regards.

Melissa