of: property: Add fw_devlink support for interrupts

This allows fw_devlink to create device links between consumers of an
interrupt and the supplier of the interrupt.

Cc: Marc Zyngier <maz@kernel.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NRob Herring <robh@kernel.org>
Reviewed-by: NThierry Reding <treding@nvidia.com>
Reviewed-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NSaravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210121225712.1118239-3-saravanak@google.comSigned-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/of/property.c

@@ -24,6 +24,7 @@
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/of_graph.h>
+#include <linux/of_irq.h>
 #include <linux/string.h>
 #include <linux/moduleparam.h>
 
@@ -1293,6 +1294,15 @@ static struct device_node *parse_gpio_compat(struct device_node *np,
 	return sup_args.np;
 }
 
+static struct device_node *parse_interrupts(struct device_node *np,
+					    const char *prop_name, int index)
+{
+	if (strcmp(prop_name, "interrupts") || index)
+		return NULL;
+
+	return of_irq_find_parent(np);
+}
+
 static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_clocks, },
 	{ .parse_prop = parse_interconnects, },
@@ -1319,6 +1329,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_pinctrl7, },
 	{ .parse_prop = parse_pinctrl8, },
 	{ .parse_prop = parse_gpio_compat, },
+	{ .parse_prop = parse_interrupts, },
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },