TQmb8xx (i.MX8QXP) Device Tree GPIO Pin Mux Fail

[christinad]

Hi!

I'm working with an TQmb8xx system on module on a custom board. I tried pin muxing the SPI0_SDI to LSIO_GPIO1_IO05 in the device tree but when I go to toggle on the GPIO, I see no power output. The device tree looks like this:

IMX8QXP_SPI0_SDI_LSIO_GPIO1_IO05    0x00000040

 I have tried changing the hexadecimal configuration with no luck and have also tried adding the following line per other forum posts, which did not work for me:

IMX8QXP_COMP_CTL_GPIO_1V8_3V3_GPIORHB_PAD  	0x000514a0

 Please advise. Thank you!

[Manuel_Salas]

Hello @christinad ,

You need to modify the mux_mode to get that pad as GPIO because as default is configured as ADMA_SPI0_SDI.

Could you please try:

IMX8QXP_SPI0_SDI_LSIO_GPIO1_IO05    0x20000040

Please try it.

Also you can modify and read the configuration pad register (4_02C0h) from memtool before to recompile your dts.

I hope this can helps to you.

Best regards.

Salas.

[christinad]

Hi Alejandro,

I updated the device tree to your configuration, however I'm still not seeing any power output after turning the gpio on. Is there anything in the SCU I need to update?

Thanks,

Christina

[Manuel_Salas]

Hello @christinad 

Could you please clarify the way you are turning the gpio?

Also, you can update the value in dts referring to this example:

https://github.com/nxp-imx/linux-imx/blob/imx_5.4.70_2.3.0/arch/arm64/boot/dts/freescale/imx8x-mek.d...

Let me know how it was.

Best regards.

Salas.

[christinad]

Hi,

I tried updating the value according to the link you sent, but the gpio is still not turning on. 

I am turning on the gpio through the sysfs interface in linux, by exporting the gpio pin, setting the direction to out and setting the value to 1.

Thanks!

[Manuel_Salas]

Hello @christinad ,

I hope you are doing well.

Could you please share your device tree?

I want to confirm the PAD is not being using by other peripheral. Also, you can try with memtool to change the registers in execution time before to re-compile the device tree.

If possible, please point to me about TQmb8xx, I cannot find information about that.

Best regards!

Salas.

[christinad]

Sorry I had a typo it's the TQma8xx https://www.tq-group.com/en/products/tq-embedded/arm-architecture/tqma8xx/

I've attached my device tree

Thanks!