PCI: dwc: Add API support to de-initialize host

Add an API to group all the tasks to be done to de-initialize host which
can then be called by any dwc core based driver implementations
while adding .remove() support in their respective drivers.
Signed-off-by: Vidya Sagar <vidyas@nvidia.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>

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

@@ -496,6 +496,14 @@ int dw_pcie_host_init(struct pcie_port *pp)
 	return ret;
 }
 
+void dw_pcie_host_deinit(struct pcie_port *pp)
+{
+	pci_stop_root_bus(pp->root_bus);
+	pci_remove_root_bus(pp->root_bus);
+	if (pci_msi_enabled() && !pp->ops->msi_host_init)
+		dw_pcie_free_msi(pp);
+}
+
 static int dw_pcie_access_other_conf(struct pcie_port *pp, struct pci_bus *bus,
 				     u32 devfn, int where, int size, u32 *val,
 				     bool write)

drivers/pci/controller/dwc/pcie-designware.h

@@ -351,6 +351,7 @@ void dw_pcie_msi_init(struct pcie_port *pp);
 void dw_pcie_free_msi(struct pcie_port *pp);
 void dw_pcie_setup_rc(struct pcie_port *pp);
 int dw_pcie_host_init(struct pcie_port *pp);
+void dw_pcie_host_deinit(struct pcie_port *pp);
 int dw_pcie_allocate_domains(struct pcie_port *pp);
 #else
 static inline irqreturn_t dw_handle_msi_irq(struct pcie_port *pp)
@@ -375,6 +376,10 @@ static inline int dw_pcie_host_init(struct pcie_port *pp)
 	return 0;
 }
 
+static inline void dw_pcie_host_deinit(struct pcie_port *pp)
+{
+}
+
 static inline int dw_pcie_allocate_domains(struct pcie_port *pp)
 {
 	return 0;