[PATCH v3] arm64: dts: qcom: shikra-evk: Add GPIO expanders

[PATCH v3] arm64: dts: qcom: shikra-evk: Add GPIO expanders

[Komal Bajaj]

Add the EVK GPIO expander definitions on the I2C3 bus. Describe the
TCA9538 and TCA9539 expanders used by EVK boards.

Co-developed-by: Faruque Ansari <faruque.ansari@oss.qualcomm.com>
Signed-off-by: Faruque Ansari <faruque.ansari@oss.qualcomm.com>
Signed-off-by: Komal Bajaj <komal.bajaj@oss.qualcomm.com>
---
Changes in v3:
- Sorted the child nodes by their unit address (sashiko, Konrad)
- Change node name to gpio from pca953x (sashiko)
- Link to v2: https://lore.kernel.org/r/20260929-shikra-gpio-expander-v2-1-98ea5808c4a6@oss.qualcomm.com

Changes in v2:
- Moved GPIO expander nodes to i2c3 (sashiko)
- Link to v1: https://lore.kernel.org/r/20260924-shikra-gpio-expander-v1-1-71929498ea44@oss.qualcomm.com
---
 arch/arm64/boot/dts/qcom/shikra-evk.dtsi | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/arch/arm64/boot/dts/qcom/shikra-evk.dtsi b/arch/arm64/boot/dts/qcom/shikra-evk.dtsi
index 7fbd6d1de19a..1c49cb52ce12 100644
--- a/arch/arm64/boot/dts/qcom/shikra-evk.dtsi
+++ b/arch/arm64/boot/dts/qcom/shikra-evk.dtsi
@@ -11,6 +11,38 @@ &gpu_zap_shader {
 	firmware-name = "qcom/shikra/a704_zap.mbn";
 };
 
+&i2c3 {
+	status = "okay";
+
+	expander0: gpio@20 {
+		compatible = "ti,tca9539";
+		reg = <0x20>;
+		#gpio-cells = <2>;
+		gpio-controller;
+	};
+
+	expander1: gpio@21 {
+		compatible = "ti,tca9539";
+		reg = <0x21>;
+		#gpio-cells = <2>;
+		gpio-controller;
+	};
+
+	expander2: gpio@38 {
+		compatible = "ti,tca9538";
+		reg = <0x38>;
+		#gpio-cells = <2>;
+		gpio-controller;
+	};
+
+	expander3: gpio@3c {
+		compatible = "ti,tca9538";
+		reg = <0x3c>;
+		#gpio-cells = <2>;
+		gpio-controller;
+	};
+};
+
 &qupv3_0 {
 	firmware-name = "qcom/shikra/qupv3fw.elf";
 

---
base-commit: 6c2cb8b8b843d216ab549b678a0d8831c43153e0
change-id: 20260924-shikra-gpio-expander-25ff4a29c848

Best regards,
-- 
Komal Bajaj <komal.bajaj@oss.qualcomm.com>

Re: [PATCH v3] arm64: dts: qcom: shikra-evk: Add GPIO expanders

[sashiko-bot]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] dts: incorrect compatible strings for I2C GPIO expanders
--

commit 1d7a662c567d09ded1460a7741dd86e406ccdb82
Author: Komal Bajaj <komal.bajaj@oss.qualcomm.com>

arm64: dts: qcom: shikra-evk: Add GPIO expanders

This commit adds the EVK GPIO expander definitions on the I2C3 bus.
It describes the TCA9538 and TCA9539 expanders used by EVK boards.

> diff --git a/arch/arm64/boot/dts/qcom/shikra-evk.dtsi b/arch/arm64/boot/dts/qcom/shikra-evk.dtsi
> index 7fbd6d1de19ad..1c49cb52ce12b 100644
> --- a/arch/arm64/boot/dts/qcom/shikra-evk.dtsi
> +++ b/arch/arm64/boot/dts/qcom/shikra-evk.dtsi
[ ... ]
> +&i2c3 {
> +	status = "okay";
> +
> +	expander0: gpio@20 {
> +		compatible = "ti,tca9539";
> +		reg = <0x20>;

[Severity: Low]
Is this the correct compatible string for the hardware present at this I2C
address?

The ti,tca9539 IC is hardcoded to respond at 0x74-0x77 and cannot physically
respond at I2C address 0x20. Are the chips present at 0x20 and 0x21 actually
TCA9535 or PCA9535 ICs, which use the 0x20-0x27 address range?

> +		#gpio-cells = <2>;
> +		gpio-controller;
> +	};
> +
> +	expander1: gpio@21 {
> +		compatible = "ti,tca9539";
> +		reg = <0x21>;
> +		#gpio-cells = <2>;
> +		gpio-controller;
> +	};
> +
> +	expander2: gpio@38 {
> +		compatible = "ti,tca9538";
> +		reg = <0x38>;

[Severity: Low]
Is this compatible string accurate for this address?

The ti,tca9538 IC is hardcoded to the 0x70-0x73 range and cannot respond at
0x38. Are the ICs located at 0x38 and 0x3c actually TCA9554 or PCA9554
expanders?

> +		#gpio-cells = <2>;
> +		gpio-controller;
> +	};
[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20261001-shikra-gpio-expander-v3-1-d30c1e8067db@oss.qualcomm.com?part=1