PCI: dra7xx: Enable MSI and legacy interrupts simultaneously

pci-dra7xx driver had a bug in that if CONFIG_PCI_MSI config is enabled, it
doesn't support legacy interrupt.  Fix it here so that both MSI and legacy
interrupts can be enabled simultaneously and the interrupt mechanism
supported by the endpoint device will be used.
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/dwc/pci-dra7xx.c

@@ -72,6 +72,7 @@ struct dra7xx_pcie {
 	int			phy_count;	/* DT phy-names count */
 	struct phy		**phy;
 	int			link_gen;
+	struct irq_domain	*irq_domain;
 };
 
 #define to_dra7xx_pcie(x)	container_of((x), struct dra7xx_pcie, pp)
@@ -142,14 +143,8 @@ static void dra7xx_pcie_enable_interrupts(struct dra7xx_pcie *dra7xx)
 			   PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MAIN, INTERRUPTS);
 	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQSTATUS_MSI,
 			   ~LEG_EP_INTERRUPTS & ~MSI);
-
-	if (IS_ENABLED(CONFIG_PCI_MSI))
-		dra7xx_pcie_writel(dra7xx,
-				   PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI, MSI);
-	else
-		dra7xx_pcie_writel(dra7xx,
-				   PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI,
-				   LEG_EP_INTERRUPTS);
+	dra7xx_pcie_writel(dra7xx, PCIECTRL_DRA7XX_CONF_IRQENABLE_SET_MSI,
+			   MSI | LEG_EP_INTERRUPTS);
 }
 
 static void dra7xx_pcie_host_init(struct pcie_port *pp)
@@ -164,8 +159,7 @@ static void dra7xx_pcie_host_init(struct pcie_port *pp)
 	dw_pcie_setup_rc(pp);
 
 	dra7xx_pcie_establish_link(dra7xx);
-	if (IS_ENABLED(CONFIG_PCI_MSI))
-		dw_pcie_msi_init(pp);
+	dw_pcie_msi_init(pp);
 	dra7xx_pcie_enable_interrupts(dra7xx);
 }
 
@@ -190,6 +184,7 @@ static const struct irq_domain_ops intx_domain_ops = {
 static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
 {
 	struct device *dev = pp->dev;
+	struct dra7xx_pcie *dra7xx = to_dra7xx_pcie(pp);
 	struct device_node *node = dev->of_node;
 	struct device_node *pcie_intc_node =  of_get_next_child(node, NULL);
 
@@ -198,9 +193,9 @@ static int dra7xx_pcie_init_irq_domain(struct pcie_port *pp)
 		return -ENODEV;
 	}
 
-	pp->irq_domain = irq_domain_add_linear(pcie_intc_node, 4,
-					       &intx_domain_ops, pp);
-	if (!pp->irq_domain) {
+	dra7xx->irq_domain = irq_domain_add_linear(pcie_intc_node, 4,
+						   &intx_domain_ops, pp);
+	if (!dra7xx->irq_domain) {
 		dev_err(dev, "Failed to get a INTx IRQ domain\n");
 		return -ENODEV;
 	}
@@ -224,7 +219,8 @@ static irqreturn_t dra7xx_pcie_msi_irq_handler(int irq, void *arg)
 	case INTB:
 	case INTC:
 	case INTD:
-		generic_handle_irq(irq_find_mapping(pp->irq_domain, ffs(reg)));
+		generic_handle_irq(irq_find_mapping(dra7xx->irq_domain,
+						    ffs(reg)));
 		break;
 	}
 
@@ -310,11 +306,9 @@ static int __init dra7xx_add_pcie_port(struct dra7xx_pcie *dra7xx,
 		return ret;
 	}
 
-	if (!IS_ENABLED(CONFIG_PCI_MSI)) {
-		ret = dra7xx_pcie_init_irq_domain(pp);
-		if (ret < 0)
-			return ret;
-	}
+	ret = dra7xx_pcie_init_irq_domain(pp);
+	if (ret < 0)
+		return ret;
 
 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "rc_dbics");
 	pp->dbi_base = devm_ioremap(dev, res->start, resource_size(res));