Pca953x 1-0020: no default pinctrl state

[johannes4422]

Hello,

currently i try to configure the gpio-pca953x to drive a PCA9574BS,118 gpio-expander, that is connected to the second i2c bus of the Jetson Nano production module with the following DT config:
fl2-cb02.dts (5.1 KB)

	pca9574_i2c2: i2c@7000c400 { // i2c1 for linux
		gpio_adapter: pca9574@20 {
				#address-cells = <1>;
				#size-cells = <0>;
				compatible = "nxp,pca9574";
				reg = <0x20>;
				pinctrl-names = "default";
				// phandle to pin-config-node: child nodes of pin controller that they configure (pinctrl-bindings.txt)
				pinctrl-0 = <>;
				interrupt-parent = <&gpio>;
				interrupts = <33 IRQ_TYPE_LEVEL_LOW>;
				gpio-controller;
				#gpio-cells = <2>;
				interrupt-controller;
				#interrupt-cells = <2>;
		};
	};

but i get the following kernel output:

[ 1490.359362] bus: 'i2c': driver_probe_device: matched device 1-0020 with driver pca953x
[ 1490.367399] bus: 'i2c': really_probe: probing driver pca953x with device 1-0020
[ 1490.374884] pca953x 1-0020: no default pinctrl state
[ 1490.380007] pca953x 1-0020: reg get err: -19
[ 1490.384382] pca953x: probe of 1-0020 rejects match -19

With a python-script i can access the gpio-expander from userspace and query its registers via i2c, so it should not be an hardware issue.

I suspect, that the line “pinctrl-0 = <>” is wrong, but reading the drivers binding documentation in Documentation/devicetree/bindings/gpio/gpio-pca953x.txt i am still puzzled if i need to define a pinctrl configuration for the pins controlled by the PCA9574BS,118 chip or if this should reference the Tegra pinmux configuration.

Any hints are highly appreciated.

Best regards,
Johannes

[kayccc]

Sorry for the late response, have you managed to get issue resolved or still need the support? Thanks

[JerryChang]

@johannes4422

				// phandle to pin-config-node: child nodes of pin controller that they configure (pinctrl-bindings.txt)
				pinctrl-0 = <>;

this part looks incomplete,
please see-also reference device tree to have implementation.
for example,
$public_sources/kernel_src/hardware/nvidia/platform/t210/porg/kernel-dts/tegra210-porg-p3448-common.dtsi

        pinmux@700008d4 {
                dvfs_pwm_active_state: dvfs_pwm_active {...}
                dvfs_pwm_inactive_state: dvfs_pwm_inactive {...}

        pwm@70110000 {
                pinctrl-0 = <&dvfs_pwm_active_state>;
                pinctrl-1 = <&dvfs_pwm_inactive_state>;

[johannes4422]

Hi Jerry,

thanks for the suggestions. I found that the ‘vcc-supply’ property as documented here: https://www.kernel.org/doc/Documentation/devicetree/bindings/gpio/gpio-pca953x.txt is not optional in the tegra linux.4.9 but required.

in the end providing a fixed regulator for this property helped:
vcc-supply = <&battery_reg>;
which solved the error: reg get err: -19

Thanks for your hints.
Best regards,
Johannes