PCIE
Rockchip kernel 4.4 Keep up with the changes in the upstream kernel, so please refer to online linux documents.
DTS
- https://www.kernel.org/doc/Documentation/devicetree/bindings/pci/rockchip-pcie.txt
- https://www.kernel.org/doc/Documentation/devicetree/bindings/phy/rockchip-pcie-phy.txt