Cannot use UART5 pins as GPIO

I am trying to use GPIO1.4 (SODIMM 19) and GPIO1.5 (SODIMM 21) as GPIO instead of UART5 pins. I have modified the device tree accordingly, but the pin states do not change when executing any of the following commands from the console:

gpioset 0 4=0
gpioset 0 4=1
gpioset 0 5=0
gpioset 0 5=1

GPIO1.4 is always high (3.3V) and GPIO1.5 is always at approx. 1.7V.

My device tree is based on the Iris v2 device tree and I have attached my diff file.

Does anybody know what is the problem?

Hi, @CristianM

In your diff file, I see that you disabled uart5 (line 495). This is good.

But in your iomuxc, you have MX6UL_PAD_GPIO1_IO04__UART5_DTE_RX and MX6UL_PAD_GPIO1_IO05__UART5_DTE_TX (lines 576 and 577).

If you are going to use SODIMM 19 and SODIMM 21 as GPIO, you need to replace pin functions accordingly to MX6UL_PAD_GPIO1_IO04__GPIO1_IO04 and MX6UL_PAD_GPIO1_IO05__GPIO1_IO05.

Let me know if this helps you.

Best regards.

It worked. Thank you!


You’re welcome :slight_smile: