[PATCH 2/4] of: irq: Add support for the new definition of "msi-parent"

[Marc Zyngier <marc.zyngier@arm.com>]

Since 126b16e2ad98 ("Docs: dt: add generic MSI bindings"),
the definition of "msi-parent" has evolved, while maintaining
some degree of compatibility. It can now express multiple MSI
controllers as parents, as well as some sideband data being
communicated to the controller.

This patch revamps the parsing of the property, iterating over
the multiple parents until a suitable irqdomain is found.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/of/irq.c | 26 +++++++++++++++++---------
 1 file changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/of/irq.c b/drivers/of/irq.c
index 55317fa..c9637cf 100644
--- a/drivers/of/irq.c
+++ b/drivers/of/irq.c
@@ -586,15 +586,23 @@ err:
  */
 void of_msi_configure(struct device *dev, struct device_node *np)
 {
-	struct device_node *msi_np;
-	struct irq_domain *d;
+	struct of_phandle_args args;
+	int index = 0;
 
-	msi_np = of_parse_phandle(np, "msi-parent", 0);
-	if (!msi_np)
-		return;
+	while (!of_parse_phandle_with_opt_args(np, "msi-parent", "#msi-cells",
+					       index, &args)) {
+		struct irq_domain *d;
 
-	d = irq_find_matching_host(msi_np, DOMAIN_BUS_PLATFORM_MSI);
-	if (!d)
-		d = irq_find_host(msi_np);
-	dev_set_msi_domain(dev, d);
+		d = irq_find_matching_host(args.np, DOMAIN_BUS_PLATFORM_MSI);
+		if (!d)
+			d = irq_find_host(args.np);
+
+		if (d) {
+			dev_set_msi_domain(dev, d);
+			return;
+		}
+
+		of_node_put(args.np);
+		index++;
+	}
 }
-- 
2.1.4