Controlling GPIO on a common port from two different cores

[Peter Langer Keysoft]

We have
nRF54H20DK (rev. 0.9.1), SDK: v2.9.0-nRF54H20-1 and the same Toolchain, IDE: VSCode + nRF Connect plugin

We need to control the GPIO LEDs from two cores (P9.00, P9.01 on the APP core and P9.02, P9.03 on the RAD core), i.e. on the same port - does this mean that the GPIO drivers on the cores must use the same memory? 

Here are the "overlapping" visualizations that indicate possible conflicts when all LED control is enabled on both cores.

Is this possible? If so, how do I need to configure the "overlay" and prj.conf files for both cores?

Br, KeySoft

[Kazi Afroza Sultana]

Hello,

The nRF54H20 is a multicore System-on-Chip (SoC) that uses an asymmetric multiprocessing (AMP) configuration. Each core is tasked with specific responsibilities and is optimized for different workloads. It is partitioned into functional blocks called ''Domains'' such as application, radio, secure, global etc. The domains containing the user-programmable main CPUs and associated functions are called Cores. 

 Most memory and peripherals can be flexibly allocated to cores at compile time. Most memory and peripherals can be flexibly allocated to cores at compile time.

P9 GPIO pins that can be configured for various functions.

Is this possible? If so, how do I need to configure the "overlay" and prj.conf files for both cores?

So, I think you should be able to control these pins independently from their respective cores without needing to share memory for the GPIO drivers.

I will show you the overlay part later.

[Kazi Afroza Sultana]

Hello,

According to documentation (Configuring your application for a custom PCB)

''The application might require board overlays for multiple cores. In this case, ensure that these overlays are consistent with each other.'' For both cores you need separate prj.conf file and device tree overlay file.

For example: For application core,

/ {
    leds {
        compatible = "gpio-leds";
        led0: led_0 {
            gpios = <&gpio9 0 GPIO_ACTIVE_LOW>;
            label = "LED0";
        };
        led1: led_1 {
            gpios = <&gpio9 1 GPIO_ACTIVE_LOW>;
            label = "LED1";
        };
    };
};

For radio core

/ {
    leds {
        compatible = "gpio-leds";
        led2: led_2 {
            gpios = <&gpio9 2 GPIO_ACTIVE_LOW>;
            label = "LED2";
        };
        led3: led_3 {
            gpios = <&gpio9 3 GPIO_ACTIVE_LOW>;
            label = "LED3";
        };
    };
};

Make sure you project config file has CONFIG_GPIO=y set.

[Peter Langer Keysoft]

Hello,

Thanks for the reply. I tried this "overlay" option before asking. I think for APP core it is necessary to disable the nodes for led2 and led3 because in the "dts" file they are enabled by default for APP. Is that right?

Br, KeySoft