PCI: layerscape: Add ls_pcie_msi_host_init()

Layerscape PCIe has its own MSI implementation.

Register ls_pcie_msi_host_init() to avoid using DesignWare's MSI.

[bhelgaas: add comment]
Signed-off-by: Minghuan Lian <Minghuan.Lian@freescale.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

drivers/pci/host/pci-layerscape.c

@@ -150,14 +150,37 @@ static void ls_pcie_host_init(struct pcie_port *pp)
 	iowrite32(0, pcie->dbi + PCIE_DBI_RO_WR_EN);
 }
 
+static int ls_pcie_msi_host_init(struct pcie_port *pp,
+				 struct msi_controller *chip)
+{
+	struct device_node *msi_node;
+	struct device_node *np = pp->dev->of_node;
+
+	/*
+	 * The MSI domain is set by the generic of_msi_configure().  This
+	 * .msi_host_init() function keeps us from doing the default MSI
+	 * domain setup in dw_pcie_host_init() and also enforces the
+	 * requirement that "msi-parent" exists.
+	 */
+	msi_node = of_parse_phandle(np, "msi-parent", 0);
+	if (!msi_node) {
+		dev_err(pp->dev, "failed to find msi-parent\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
 static struct pcie_host_ops ls1021_pcie_host_ops = {
 	.link_up = ls1021_pcie_link_up,
 	.host_init = ls1021_pcie_host_init,
+	.msi_host_init = ls_pcie_msi_host_init,
 };
 
 static struct pcie_host_ops ls_pcie_host_ops = {
 	.link_up = ls_pcie_link_up,
 	.host_init = ls_pcie_host_init,
+	.msi_host_init = ls_pcie_msi_host_init,
 };
 
 static struct ls_pcie_drvdata ls1021_drvdata = {