Please let me introduce some concepts here and then answer your question.
- The sor and sor1 in the device tree represent the dp0 and dp1 pin respectively.
- The tegradc means tegra display controller. It is software controller to control each sor.
According to the DT you pasted, you can see that tegradc.0 (54200000) is coupled with sor1 and tegradc.1 is coupled with sor(sor0)
Each sor has its own functionality inside it. So you can see dp-display and hdmi-display there. The default DT matches the NV devkit behavior.
- What files do I need to change ?
There is no precise answer for your question, because you can change anything within any layers of devicetree.
You can firstly check dts name from command “dmesg |grep dts” on your device. If you are using default jetapck, it will give you something like tegra210-p3448-0002-p3449-0000-b00.dts.
Then, open the file and check the content. You shall see that includes the file tegra210-porg-p3448-common.dtsi. You can either modify tegra210-p3448-0002-p3449-0000-b00.dts or tegra210-porg-p3448-common.dtsi. Only the last one touched those nodes will take effect.
For example, tegra210-p3448-0002-p3449-0000-b00.dts is the final dts file that will be flashed into board, thus if you disable tegradc at tegra210-p3448-0002-p3449-0000-b00.dts, then even though you enable tegradc in tegra210-porg-p3448-common.dtsi, it will get disabled.
How must change the file ?
If you want to enable SOR1 as DP port, then modify sor1 to same configuration as sor. Disable the hdmi-display under sor1 and enable dp-display. Change the “nvidia,xbar-ctrl” to match the hardware design.
- What about the DP1_HPD connection ?
I think the default setting shall work.
And do I need to turn off HDMI (e.g. i2c) ?
Disable corresponding tegradc and sor.