[PATCH v4 6/9] PCI: dwc: Add support to use non default msi_irq_chip

[Kishon Vijay Abraham I]

Platforms using DesignWare IP use dw_pci_msi_bottom_irq_chip for
configuring the MSI controller logic within the DesignWare IP. However
certain platforms like Keystone (K2G) which uses DesignWare IP have
their own MSI controller logic. For handling such platforms,
the irqchip ops use msi_irq_ack(), msi_set_irq(), msi_clear_irq()
callback functions.

Add support to use different msi_irq_chip with default as
dw_pci_msi_bottom_irq_chip. This is in preparation to get rid of
msi_irq_ack(), msi_set_irq(), msi_clear_irq() and other Keystone
specific dw_pcie_host_ops.

Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
---
 drivers/pci/controller/dwc/pcie-designware-host.c | 5 ++++-
 drivers/pci/controller/dwc/pcie-designware.h      | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/controller/dwc/pcie-designware-host.c b/drivers/pci/controller/dwc/pcie-designware-host.c
index 721d60a5d9e4..042de09b0451 100644
--- a/drivers/pci/controller/dwc/pcie-designware-host.c
+++ b/drivers/pci/controller/dwc/pcie-designware-host.c
@@ -245,7 +245,7 @@ static int dw_pcie_irq_domain_alloc(struct irq_domain *domain,
 
 	for (i = 0; i < nr_irqs; i++)
 		irq_domain_set_info(domain, virq + i, bit + i,
-				    &dw_pci_msi_bottom_irq_chip,
+				    pp->msi_irq_chip,
 				    pp, handle_edge_irq,
 				    NULL, NULL);
 
@@ -277,6 +277,9 @@ int dw_pcie_allocate_domains(struct pcie_port *pp)
 	struct dw_pcie *pci = to_dw_pcie_from_pp(pp);
 	struct fwnode_handle *fwnode = of_node_to_fwnode(pci->dev->of_node);
 
+	if (!pp->msi_irq_chip)
+		pp->msi_irq_chip = &dw_pci_msi_bottom_irq_chip;
+
 	pp->irq_domain = irq_domain_create_linear(fwnode, pp->num_vectors,
 					       &dw_pcie_msi_domain_ops, pp);
 	if (!pp->irq_domain) {
diff --git a/drivers/pci/controller/dwc/pcie-designware.h b/drivers/pci/controller/dwc/pcie-designware.h
index 9943d8c68335..cb6eeb062f47 100644
--- a/drivers/pci/controller/dwc/pcie-designware.h
+++ b/drivers/pci/controller/dwc/pcie-designware.h
@@ -176,6 +176,7 @@ struct pcie_port {
 	struct irq_domain	*irq_domain;
 	struct irq_domain	*msi_domain;
 	dma_addr_t		msi_data;
+	struct irq_chip		*msi_irq_chip;
 	u32			num_vectors;
 	u32			irq_status[MAX_MSI_CTRLS];
 	raw_spinlock_t		lock;
-- 
2.17.1