PCI: cadence-ep: Introduce cdns_pcie_ep_disable() helper for cleanup

Introduce the helper function cdns_pcie_ep_disable() which will undo the
configuration performed by cdns_pcie_ep_setup(). Also, export it for use
by the existing callers of cdns_pcie_ep_setup(), thereby allowing them
to cleanup on their exit path.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://patch.msgid.link/20250417124408.2752248-4-s-vadapalli@ti.com

Author: Siddharth-Vadapalli-at-TI

drivers/pci/controller/cadence/pcie-cadence-ep.c

@@ -646,6 +646,17 @@ static const struct pci_epc_ops cdns_pcie_epc_ops = {
 	.get_features	= cdns_pcie_ep_get_features,
 };
 
+void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep)
+{
+	struct device *dev = ep->pcie.dev;
+	struct pci_epc *epc = to_pci_epc(dev);
+
+	pci_epc_deinit_notify(epc);
+	pci_epc_mem_free_addr(epc, ep->irq_phys_addr, ep->irq_cpu_addr,
+			      SZ_128K);
+	pci_epc_mem_exit(epc);
+}
+EXPORT_SYMBOL_GPL(cdns_pcie_ep_disable);
 
 int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 {

drivers/pci/controller/cadence/pcie-cadence.h

@@ -544,11 +544,16 @@ static inline void __iomem *cdns_pci_map_bus(struct pci_bus *bus, unsigned int d
 
 #if IS_ENABLED(CONFIG_PCIE_CADENCE_EP)
 int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep);
+void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep);
 #else
 static inline int cdns_pcie_ep_setup(struct cdns_pcie_ep *ep)
 {
 	return 0;
 }
+
+static inline void cdns_pcie_ep_disable(struct cdns_pcie_ep *ep)
+{
+}
 #endif
 
 void cdns_pcie_detect_quiet_min_delay_set(struct cdns_pcie *pcie);