[PATCH v2 1/2] of: property: Add fw_devlink support for "gpio" and "gpios" binding

[Saravana Kannan]

To provide backward compatibility for boards that use deprecated DT
bindings, we need to add fw_devlink support for "gpio" and "gpios".

We also need to ignore these properties on nodes with "gpio-hog"
property because their gpio[s] are all supplied by the parent node.

Cc: linux-tegra <linux-tegra@xxxxxxxxxxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Bartosz Golaszewski <bgolaszewski@xxxxxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
Fixes: e590474768f1 ("driver core: Set fw_devlink=on by default")
Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Reviewed-by: Thierry Reding <treding@xxxxxxxxxx>
Tested-by: Jon Hunter <jonathanh@xxxxxxxxxx>
Signed-off-by: Saravana Kannan <saravanak@xxxxxxxxxx>
---
 drivers/of/property.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/of/property.c b/drivers/of/property.c
index 5f9eed79a8aa..b2ea1951d937 100644
--- a/drivers/of/property.c
+++ b/drivers/of/property.c
@@ -1271,6 +1271,28 @@ static struct device_node *parse_iommu_maps(struct device_node *np,
 	return of_parse_phandle(np, prop_name, (index * 4) + 1);
 }
 
+static struct device_node *parse_gpio_compat(struct device_node *np,
+					     const char *prop_name, int index)
+{
+	struct of_phandle_args sup_args;
+
+	if (strcmp(prop_name, "gpio") && strcmp(prop_name, "gpios"))
+		return NULL;
+
+	/*
+	 * Ignore node with gpio-hog property since its gpios are all provided
+	 * by its parent.
+	 */
+	if (of_find_property(np, "gpio-hog", NULL))
+		return NULL;
+
+	if (of_parse_phandle_with_args(np, prop_name, "#gpio-cells", index,
+				       &sup_args))
+		return NULL;
+
+	return sup_args.np;
+}
+
 static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_clocks, },
 	{ .parse_prop = parse_interconnects, },
@@ -1296,6 +1318,7 @@ static const struct supplier_bindings of_supplier_bindings[] = {
 	{ .parse_prop = parse_pinctrl6, },
 	{ .parse_prop = parse_pinctrl7, },
 	{ .parse_prop = parse_pinctrl8, },
+	{ .parse_prop = parse_gpio_compat, },
 	{ .parse_prop = parse_regulators, },
 	{ .parse_prop = parse_gpio, },
 	{ .parse_prop = parse_gpios, },
-- 
2.30.0.296.g2bfb1c46d8-goog