pci: Add Rockchip dwc based PCIe controller driver

Add Rockchip dwc based PCIe controller driver for rk356x platform.
Driver support Gen3 by operating as a Root complex.
Signed-off-by: NShawn Lin <shawn.lin@rock-chips.com>
Reviewed-by: NSimon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang<kever.yang@rock-chips.com>

drivers/pci/Kconfig

@@ -281,6 +281,15 @@ config PCIE_ROCKCHIP
 	  Say Y here if you want to enable PCIe controller support on
 	  Rockchip SoCs.
 
+config PCIE_DW_ROCKCHIP
+	bool "Rockchip DesignWare based PCIe controller"
+	depends on ARCH_ROCKCHIP
+	select DM_PCI
+	select PHY_ROCKCHIP_SNPS_PCIE3
+	help
+	  Say Y here if you want to enable DW PCIe controller support on
+	  Rockchip SoCs.
+
 config PCI_BRCMSTB
 	bool "Broadcom STB PCIe controller"
 	depends on DM_PCI

drivers/pci/Makefile

@@ -48,5 +48,6 @@ obj-$(CONFIG_PCIE_INTEL_FPGA) += pcie_intel_fpga.o
 obj-$(CONFIG_PCI_KEYSTONE) += pcie_dw_ti.o
 obj-$(CONFIG_PCIE_MEDIATEK) += pcie_mediatek.o
 obj-$(CONFIG_PCIE_ROCKCHIP) += pcie_rockchip.o
+obj-$(CONFIG_PCIE_DW_ROCKCHIP) += pcie_dw_rockchip.o
 obj-$(CONFIG_PCI_BRCMSTB) += pcie_brcmstb.o
 obj-$(CONFIG_PCI_OCTEONTX) += pci_octeontx.o

drivers/phy/rockchip/Kconfig

@@ -23,6 +23,9 @@ config PHY_ROCKCHIP_SNPS_PCIE3
 	depends on PHY && ARCH_ROCKCHIP
 	help
 	  Support for Rockchip PCIe3 PHY with Synopsys IP block.
+	  It could support PCIe Gen3 single root complex, and could
+	  also be able splited into multiple combinations of lanes.
+
 
 config PHY_ROCKCHIP_TYPEC
 	bool "Rockchip TYPEC PHY Driver"