GigaDisplayTouch - issues with the gt911 object and defer-init

[KurtE]

I was trying to get the GigaDisplay shield touch code working again with the current ArduinoCore-zephyr
and went into the zephyr branch of the Arduino_GigaDisplayTouch project and added in the call
(void)zephyr::arduino::init_dev_apply_pinctrl(dev);
arduino-libraries/Arduino_GigaDisplayTouch#18

And it still did not work the issue appears to be with the giga device tree overlay file contained within the variant has:

&i2c4 {
	status = "okay";
	zephyr,deferred-init;
	gc2145: gc2145@3c {
		compatible = "galaxycore,gc2145";
		reg = <0x3c>;
		zephyr,deferred-init;
		reset-gpios = <&gpiod 4 GPIO_ACTIVE_LOW>;
		pwdn-gpios = <&gpioa 1 GPIO_ACTIVE_LOW>;

		port {
			gc2145_ep_out: endpoint {
				remote-endpoint-label = "dcmi_ep_in";
			};
		};
	};
}

But the display Device tree information is defined within zephyr in the boards/shields/arduino_giga_display_shield
under boards and the giga and is currently defined as:

&i2c4 {
	pinctrl-0 = <&i2c4_scl_pb6 &i2c4_sda_ph12>;
	pinctrl-names = "default";
	clock-frequency = <I2C_BITRATE_FAST>;
	status = "okay";

	gt911: gt911@5d {
		compatible = "goodix,gt911";
		reg = <0x5d>;
		alt-addr = <0x14>;
		reset-gpios = <&gpioi 2 GPIO_ACTIVE_LOW>;
		irq-gpios = <&gpioi 1 GPIO_ACTIVE_HIGH>;
	};
};

So in the device tree the I2c4 object is deferred-init but the gt911 object is not that relies on it.
I was able to get touch to work again by marking it here under zephyr as deferred-init.

Question is, do you want to change it at that level? Or in the variant? But what if you have different
variant that does not include the shield?

EDIT: Can be closed after these are merged:

• Zephyr - Add call to (void)zephyr::arduino::init_dev_apply_pinctrl(dev) arduino-libraries/Arduino_GigaDisplayTouch#18
• variant: giga: set gt911 as deferred-init #489

[dani-clo]

Good catch! gt911 should also be marked as zephyr,deferred-init, since the underlying i2c4 bus is not initialized by Zephyr at boot. Adding the property in the Giga overlay is the correct place in my opinion.

Question is, do you want to change it at that level? Or in the variant? But what if you have different variant that does not include the shield?

In that case the final .dts will include the gt911 node only when the shield is enabled, so marking it as deferred-init in the Giga overlay is still the correct behavior, where we also set its i2c bus to deferred-init.