PCI: kirin: Add MSI support

Add support for MSI to the kirin host controller driver, based
on the generic dwc infrastructure.

Signed-off-by: Xiaowei Song <songxiaowei@hisilicon.com>
Signed-off-by: Yao Chen <chenyao11@huawei.com>
[lorenzo.pieralisi@arm.com: updated commit log]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>

drivers/pci/controller/dwc/pcie-kirin.c

@@ -430,6 +430,9 @@ static int kirin_pcie_host_init(struct pcie_port *pp)
 {
 	kirin_pcie_establish_link(pp);
 
+	if (IS_ENABLED(CONFIG_PCI_MSI))
+		dw_pcie_msi_init(pp);
+
 	return 0;
 }
 
@@ -445,9 +448,34 @@ static const struct dw_pcie_host_ops kirin_pcie_host_ops = {
 	.host_init = kirin_pcie_host_init,
 };
 
+static int kirin_pcie_add_msi(struct dw_pcie *pci,
+				struct platform_device *pdev)
+{
+	int irq;
+
+	if (IS_ENABLED(CONFIG_PCI_MSI)) {
+		irq = platform_get_irq(pdev, 0);
+		if (irq < 0) {
+			dev_err(&pdev->dev,
+				"failed to get MSI IRQ (%d)\n", irq);
+			return irq;
+		}
+
+		pci->pp.msi_irq = irq;
+	}
+
+	return 0;
+}
+
 static int __init kirin_add_pcie_port(struct dw_pcie *pci,
 				      struct platform_device *pdev)
 {
+	int ret;
+
+	ret = kirin_pcie_add_msi(pci, pdev);
+	if (ret)
+		return ret;
+
 	pci->pp.ops = &kirin_pcie_host_ops;
 
 	return dw_pcie_host_init(&pci->pp);