i.MX RT Crossover MCUsのトピックRe: Retrieving a GPIO's direction (input/output)

Retrieving a GPIO's direction (input/output)

nadavintel — Sun, 02 Oct 2022 05:43:28 GMT

Hello friends,

During run-time, I want to get the direction (input/output) of a GPIO pin.

I was expecting something like: gpio_pin_direction_t F(GPIO_Type *base, uint32_t port).

Was searching fsl_gpio.h & Reference Manual: GPIO. No such method is found :[

Is there any way to retrieve a GPIO pin direction during run-time?

Thank you.

Re: Retrieving a GPIO's direction (input/output)

carstengroen — Sun, 02 Oct 2022 12:59:32 GMT

Look in the users manual for the chip or look in the fsl_gpio.c file ? There is no guarantee that there is a function in the SDK for every single use of the registers.
Hint: look at GDIR register for the specific port.....

Re: Retrieving a GPIO's direction (input/output)

Julián_AragónM — Mon, 03 Oct 2022 16:27:27 GMT

Currently there is no API function that specifically reads the direction from a GPIO pin;

The GDIR register functions as direction control when the IOMUXC is in GPIO mode. Each bit specifies the direction of a one-bit signal.

Julin_AragnM_0-1664814421548.png
Julin_AragnM_1-1664814421549.png

The GDIR register is a read/write register which you can read during run-time to store or obtain the direction (input/output) of a GPIO pin. The example you provided (gpio_pin_direction_t F(GPIO_Type *base, uint32_t port)) is a good way of implementing this function.

I hope you find this helpful! If you have any doubts about the register do not hesitate to ask.

Best regards, Julian