PCI: tegra: Add support for PCIe endpoint mode in Tegra194

Add support for the endpoint mode of Synopsys DesignWare core based
dual mode PCIe controllers present in Tegra194 SoC.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Thierry Reding <treding@nvidia.com>

drivers/pci/controller/dwc/Kconfig

@@ -248,14 +248,37 @@ config PCI_MESON
 	  implement the driver.
 
 config PCIE_TEGRA194
-	tristate "NVIDIA Tegra194 (and later) PCIe controller"
+	tristate
+
+config PCIE_TEGRA194_HOST
+	tristate "NVIDIA Tegra194 (and later) PCIe controller - Host Mode"
 	depends on ARCH_TEGRA_194_SOC || COMPILE_TEST
 	depends on PCI_MSI_IRQ_DOMAIN
 	select PCIE_DW_HOST
 	select PHY_TEGRA194_P2U
+	select PCIE_TEGRA194
+	help
+	  Enables support for the PCIe controller in the NVIDIA Tegra194 SoC to
+	  work in host mode. There are two instances of PCIe controllers in
+	  Tegra194. This controller can work either as EP or RC. In order to
+	  enable host-specific features PCIE_TEGRA194_HOST must be selected and
+	  in order to enable device-specific features PCIE_TEGRA194_EP must be
+	  selected. This uses the DesignWare core.
+
+config PCIE_TEGRA194_EP
+	tristate "NVIDIA Tegra194 (and later) PCIe controller - Endpoint Mode"
+	depends on ARCH_TEGRA_194_SOC || COMPILE_TEST
+	depends on PCI_ENDPOINT
+	select PCIE_DW_EP
+	select PHY_TEGRA194_P2U
+	select PCIE_TEGRA194
 	help
-	  Say Y here if you want support for DesignWare core based PCIe host
-	  controller found in NVIDIA Tegra194 SoC.
+	  Enables support for the PCIe controller in the NVIDIA Tegra194 SoC to
+	  work in host mode. There are two instances of PCIe controllers in
+	  Tegra194. This controller can work either as EP or RC. In order to
+	  enable host-specific features PCIE_TEGRA194_HOST must be selected and
+	  in order to enable device-specific features PCIE_TEGRA194_EP must be
+	  selected. This uses the DesignWare core.
 
 config PCIE_UNIPHIER
 	bool "Socionext UniPhier PCIe controllers"

drivers/pci/controller/dwc/pcie-designware-ep.c

@@ -18,6 +18,7 @@ void dw_pcie_ep_linkup(struct dw_pcie_ep *ep)
 
 	pci_epc_linkup(epc);
 }
+EXPORT_SYMBOL_GPL(dw_pcie_ep_linkup);
 
 void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
 {
@@ -25,6 +26,7 @@ void dw_pcie_ep_init_notify(struct dw_pcie_ep *ep)
 
 	pci_epc_init_notify(epc);
 }
+EXPORT_SYMBOL_GPL(dw_pcie_ep_init_notify);
 
 static void __dw_pcie_ep_reset_bar(struct dw_pcie *pci, enum pci_barno bar,
 				   int flags)
@@ -536,6 +538,7 @@ int dw_pcie_ep_init_complete(struct dw_pcie_ep *ep)
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(dw_pcie_ep_init_complete);
 
 int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 {
@@ -630,3 +633,4 @@ int dw_pcie_ep_init(struct dw_pcie_ep *ep)
 
 	return dw_pcie_ep_init_complete(ep);
 }
+EXPORT_SYMBOL_GPL(dw_pcie_ep_init);