GIGA Display Shield: How to capture touch events?

[KurtE]

I am trying to understand how to have an Arduino sketch be able to use the touch events generated
by the GIGA Display shield.

If I look at the overlay file, that is defined for the giga in zephyr:
D:\github\zephyr\boards\shields\giga_display_shield\boards\arduino_giga_r1_m7.overlay

It has:

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

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

So it is using the gt911 input ... It has status of okay so it starts up. with IRQ on GPIO I1...
And it is probably using the code in zephyr\drivers\input\input_gt911.c

I found the zephyr example: samples\subsys\input\draw_touch_events, which I was curious if it would
build and run... So far did not build.

D:/zephyrproject/zephyr/drivers/display/display_stm32_ltdc.c:422:25: error: 'CONFIG_VIDEO_BUFFER_SMH_ATTRIBUTE' undeclared (first use in this function)
  422 |                         CONFIG_VIDEO_BUFFER_SMH_ATTRIBUTE,
      |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
D:/zephyrproject/zephyr/drivers/display/display_stm32_ltdc.c:422:25: note: each undeclared identifier is reported only once for each function it appears in
[41/48] Linking C static library zephyr\kernel\libkernel.a

Thought I would try doing the same thing in a sketch, however I don't think this will work.

static void touch_event_callback(struct input_event *evt, void *user_data)
{
	if (evt->code == INPUT_ABS_X) {
		touch_point.x = evt->value;
	}
	if (evt->code == INPUT_ABS_Y) {
		touch_point.y = evt->value;
	}
	if (evt->code == INPUT_BTN_TOUCH) {
		touch_point.pressed = evt->value;
	}
	if (evt->sync) {
		k_sem_give(&sync);
	}
}
INPUT_CALLBACK_DEFINE(touch_dev, touch_event_callback, NULL);

As I don't believe the INPUT_CALLBACK_DEFINE will work in a sketch?

Wondering best way to handle this?

Potentially, maybe define some callback within the ArduinoCore-zephyr code space.
Like maybe in loader\fixups.c ?

Turn off the interrupt? And try to poll it?

Suggestions?

[KurtE]

Quick note:
The example sketch: ~/zephyrproject/zephyr/samples/subsys/input/input_dump
does build and run.
From the monitor window:

I: input event: dev=gt911@5d             type= 3 code=  0 value=373
I: input event: dev=gt911@5d             type= 3 code=  1 value=444
I: input event: dev=gt911@5d         SYN type= 1 code=330 value=1
I: input event: dev=gt911@5d             type= 3 code=  0 value=373
I: input event: dev=gt911@5d             type= 3 code=  1 value=444
I: input event: dev=gt911@5d         SYN type= 1 code=330 value=1
I: input event: dev=gt911@5d             type= 3 code=  0 value=373
I: input event: dev=gt911@5d             type= 3 code=  1 value=444
I: input event: dev=gt911@5d         SYN type= 1 code=330 value=1
I: input event: dev=gt911@5d             type= 3 code=  0 value=373
I: input event: dev=gt911@5d             type= 3 code=  1 value=444

Note: if you hold your finger down at all, you will see a lot of messages like:

I: input event: dev=gt911@5d             type= 3 code=  0 value=368
I: input event: dev=gt911@5d             type= 3 code=  1 value=424
I: input event: dev=gt911@5d         SYN type= 1 code=330 value=1
I: input event: dev=gt911@5d             type= 3 coW: Event dropped, queue full, not blocking in syswq.
de=  0 value=368
I: input event: dev=gt911@5d             type= 3 codW: Event dropped, queue full, not blocking in syswq.
W: Event dropped, queue full, not blocking in syswq.
e=  1 value=424W: Event dropped, queue full, not blocking in syswq.
W: Event dropped, queue full, not blocking in syswq.
W: Event dropped, queue full, not blocking in syswq.

[KurtE]

Edit: meant to add it to this issue instead of display library issue.

Quick notes: It was unclear to me how I might adapt the Arduino_GigaDisplayTouch library to zephyr. There is a PT911 object
defined in the overlay for the board GIGA under the Shield (GIGA Display Shield), that I know is defined and running.

As as soon as I touch the display I get lots of these messages in the monitor window:

[00:00:25.648,000] <wrn> input: Event dropped, queue full, not blocking in syswq.
[00:00:25.658,000] <wrn> input: Event dropped, queue full, not blocking in syswq.
[00:00:25.669,000] <wrn> input: Event dropped, queue full, not blocking in syswq.
[00:00:25.679,000] <wrn> input: Event dropped, queue full, not blocking in syswq.

I know that the PT911 class is looking for me to hook up a callback function. like some of the input samples show:
INPUT_CALLBACK_DEFINE(touch_dev, touch_event_callback, NULL);
But I know that adding this define to a library that gets loaded in our LLTEXT code won't work. Was not sure if there are any
Dynamic ways to setup the callback. So I asked up on Zephyr Discussion:
zephyrproject-rtos/zephyr#89415

The response I received:
zephyrproject-rtos/zephyr#89415 (comment)
From fabiobaltieri,

Can't be done at the moment, but it'd be very easy to a static callback that goes through a dynamic list. Or just implement the >whole thing in the subsystem and make it Kconfig optional, don't see a reason not to accept such a contribution.

My read of this is, that I would need to add the callback code into some place that is built into the loader, like maybe fixups.c
and maybe that code would receive the callbacks and save the touch information and maybe set a semaphore or the like
and then the library code could detect the semaphore and retrieve the last callback information.
Probably beyond my pay grade 😆, especially if your plans are to always use LVGL.