[PATCH v2] arm64: dts: rockchip: Add the GPIO expander to Kobol Helios64

[Igor Velkov via B4 Relay]

From: Igor Velkov <iav@xxxxxx>

Helios64 has an ON Semiconductor PCA9655E 16-bit GPIO expander at 0x20
on I2C2, powered from VCC3V3_SYS_S3. Its 16 lines go to pins 4-19 of
the P5 GPIO header, one line per pin in order, so name them after the
pins. Its INT# output goes to GPIO0_B1 with an external pull-up (R59
to 1V8_S3), so the pin has no internal bias. Schematic, sheets 34 and
35:
https://wiki.kobol.io/helios64/files/schematics/Helios64_Schematics_Rev1.2.pdf

Assisted-by: LLM
Signed-off-by: Igor Velkov <iav@xxxxxx>
---
The node is the one tested on the board in v1; the line names are
checked with dt-validate only.
---
Changes in v2:
- Drop the binding patch, applied by Bartosz as 356cab616b6f.
- Name the lines after the P5 header pins, label the node p5_gpio.
- Rebase on for-next.
- Link to v1: https://lore.kernel.org/r/20261009-helios64-pca9655-v1-0-673ee4432650@xxxxxx
---
 .../boot/dts/rockchip/rk3399-kobol-helios64.dts    | 25 ++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts b/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts
index 63ad79b4c8ac..df993cbb17c8 100644
--- a/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts
+++ b/arch/arm64/boot/dts/rockchip/rk3399-kobol-helios64.dts
@@ -461,6 +461,25 @@ &i2c2 {
 	i2c-scl-falling-time-ns = <30>;
 	status = "okay";
 
+	p5_gpio: gpio@20 {
+		compatible = "onnn,pca9655", "nxp,pca9555";
+		reg = <0x20>;
+		gpio-controller;
+		#gpio-cells = <2>;
+		/* All 16 lines go to pins 4-19 of the P5 GPIO header */
+		gpio-line-names = "PIN_4", "PIN_5", "PIN_6", "PIN_7",
+				  "PIN_8", "PIN_9", "PIN_10", "PIN_11",
+				  "PIN_12", "PIN_13", "PIN_14", "PIN_15",
+				  "PIN_16", "PIN_17", "PIN_18", "PIN_19";
+		interrupt-controller;
+		#interrupt-cells = <2>;
+		interrupt-parent = <&gpio0>;
+		interrupts = <RK_PB1 IRQ_TYPE_LEVEL_LOW>;
+		pinctrl-names = "default";
+		pinctrl-0 = <&exp16_int_l>;
+		vcc-supply = <&vcc3v3_sys_s3>;
+	};
+
 	temp@4c {
 		compatible = "national,lm75";
 		reg = <0x4c>;
@@ -501,6 +520,12 @@ user1_btn: user1-btn {
 		};
 	};
 
+	expander {
+		exp16_int_l: exp16-int-l {
+			rockchip,pins = <0 RK_PB1 RK_FUNC_GPIO &pcfg_pull_none>;
+		};
+	};
+
 	fan {
 		fan1_sense: fan1-sense {
 			rockchip,pins = <4 RK_PC5 RK_FUNC_GPIO &pcfg_pull_none>;

---
base-commit: d2abcbb905b0e4b2e06b257fa1e5bcf4faa6dbda
change-id: 20261009-helios64-pca9655-39643c2acf4d

Best regards,
-- 
Igor Velkov <iav@xxxxxx>