LS1028A device tree "lane-mapping"

[CGW]

I have a question about the NXP reference design device tree.

&hdptx0 {

        lane-mapping = <0x4e>;

        status = "okay";

        power-gpios = <&gpio4 10 0>;

};

I can see in source code:

                /* Line swaping */

                cdns_mhdp_reg_write(mhdp, LANES_CONFIG, 0x00400000 | lane_mapping);

LANES_CONFIG is set to 0x0814.

I cannot find any information about the “lane-mapping” parameter. What is it and how do I know what value it needs to be set at?

I cannot find any references to “lane-mapping” for display port in any of the NXP documentation.

Thank you. Your help is greatly appreciated.

[Oswalag]

Hello,

It is the value according to the DP lane configuration, you can refer to the table below for the ls1028ardb:

following the configuration of the table is:

 1032 --> 01 00 11 10 --> 0x4e