[PATCH V4 1/2] PCI: dwc: Add API support to de-initialize host

[Vidya Sagar]

Add an API to group all the tasks to be done to de-initialize host which
can then be called by any DesignWare core based driver implementations
while adding .remove() support in their respective drivers.

Signed-off-by: Vidya Sagar <vidyas@xxxxxxxxxx>
Acked-by: Gustavo Pimentel <gustavo.pimentel@xxxxxxxxxxxx>
---
Changes from v3:
* Added check if (pci_msi_enabled() && !pp->ops->msi_host_init) before calling
  dw_pcie_free_msi() API to mimic init path

Changes from v2:
* Rebased on top of linux-next top of the tree branch

Changes from v1:
* s/Designware/DesignWare

 drivers/pci/controller/dwc/pcie-designware-host.c | 8 ++++++++
 drivers/pci/controller/dwc/pcie-designware.h      | 5 +++++
 2 files changed, 13 insertions(+)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 77db32529319..d069e4290180 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/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)
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index deab426affd3..4f48ec78c7b9 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -348,6 +348,7 @@ 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)
@@ -372,6 +373,10 @@ 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;
-- 
2.17.1