Zephyr, nrf5340 and pin number

[Riccardo Gaiati]

Hi,

I am using the nrfx GPIOTE driver to manage the output, input and interrupt on a nRF5340 on top of Zephyr Framework.

I know I can use the GPIO Api from Zephyr, but this is not my case.

I would like to retrieve the absolute pin numbers starting from the device tree definition and provide them to the functions of GPIOTE driver.

In order to do that i need to retrieve also the port number.

As far i can see the port number is contained in the data structure gpio_nrfx_cfg pointed by member void* config of the structure  gpio_dt_spec.port.

The data type gpio_nrfx_cfg  is defined in gpio_nrfx.c, so not publicly exposed.

Is there a more elegant way to retrieve the absolute pin number (port number * 32 + pin number) starting from the device tree definition ?

Thanks in advance!

Kind regards

Riccardo

[Jørgen Holmefjord]

Hi,

There is an existing example in nRF Connect SDK/Zephyr that shows how to use the GPIOTE and PPI peripherals using nrfx drivers.

These lines shows how you can get the GPIOs from the devicetree, for pins on P1, you can use gpio1 in the devicetree.

Best regards,
Jørgen

[Riccardo Gaiati]

Hi,

i came out with this approach:

#define GPIO_PORT(pin)    DT_PROP_BY_PHANDLE_IDX(DT_NODELABEL(pin), gpios, 0, port)
#define GPIO_PIN(pin)     DT_GPIO_PIN(DT_ALIAS(pin), gpios)
#define GPIO_ABS_PIN(pin) NRF_GPIO_PIN_MAP(GPIO_PORT(pin), GPIO_PIN(pin))

where pin is the label used (in bold) in the device tree file (see below).

leds {

        compatible = "gpio-leds";

        led0: led_0 {

            gpios = <&gpio1 7 GPIO_ACTIVE_LOW>;

            label = "Green LED 0";

        };

[Jørgen Holmefjord]

Hi,

This looks like a good approach, it is quite similar to the helper macros defined in the nrf9160dk_nrf52840 board file.

Best regards,
Jørgen