[PATCH] ARM: dts: koelsch: Configure pull-up for SOFT_SW GPIO keys

[Geert Uytterhoeven <geert+renesas@xxxxxxxxx>]

The GPIO pins connected to the 4 Software Switches ("SOFT_SW", SW2) do
not have external pull-up resistors, but rely on internal pull-ups being
enabled.  Fortunately this is satisfied by the initial state of these
pins.

Make this explicit by enabling bias-pull-up, to remove the dependency on
initial state and/or boot loader configuration.

Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
---
To be queued in renesas-devel for v5.13.

It is safe to apply this before R-Car M2-W bias support[1] has landed,
as pinctrl_bind_pins() does not consider -ENOTSUPP a fatal error.

[1] https://lore.kernel.org/r/20210303132619.3938128-1-geert+renesas@xxxxxxxxx
---
 arch/arm/boot/dts/r8a7791-koelsch.dts | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/r8a7791-koelsch.dts b/arch/arm/boot/dts/r8a7791-koelsch.dts
index 751e07fb102cf454..c6c93c4452ee1e88 100644
--- a/arch/arm/boot/dts/r8a7791-koelsch.dts
+++ b/arch/arm/boot/dts/r8a7791-koelsch.dts
@@ -81,6 +81,9 @@ lbsc {
 	keyboard {
 		compatible = "gpio-keys";
 
+		pinctrl-0 = <&sw2_pins>;
+		pinctrl-names = "default";
+
 		key-1 {
 			gpios = <&gpio5 0 GPIO_ACTIVE_LOW>;
 			linux,code = <KEY_1>;
@@ -615,6 +618,11 @@ sound_clk_pins: sound_clk {
 		groups = "audio_clk_a";
 		function = "audio_clk";
 	};
+
+	sw2_pins: sw2 {
+		pins = "GP_5_0", "GP_5_1", "GP_5_2", "GP_5_3";
+		bias-pull-up;
+	};
 };
 
 &ether {
-- 
2.25.1