imx6ul-evk GPIO3 Unable to operate

[zhangbin_eos]

Board: imx6ul-evk

BSP: fsl-yocto-L4.1.15_2.0.0-ga

I want set GPIO3_05 and GPIO3_07 to be output gpios.

To ensure that LCD drivers are not affected, I removed the LCD drivers from the kernel configuration.And delete LCD related content in DTS.

Then I use sysfs interface to control GPIO for testing.But no level changes were tested.

The following is my operation process:

• In the board

cd /sys/class/gpio/

echo  69 >  export    # 69 is GPIO3_05

echo  71 >  export    # 71 is GPIO3_07

echo 'out' > gpio69/direction

echo 'out' > gpio71/direction

echo 0  > gpio69/value

echo 0  > gpio71/value

echo 1  > gpio69/value  # Can't measure high level

echo 1  > gpio71/value  # Can't measure high level

When I  use sysfs interface to control GPIO1_26 and GPIO1_27,they are  ok.

Is there a mistake in my operation? Please help me!

[igorpadykov]

Hi 斌 张 

one can try with i.MX 6UltraLite EVK Linux Binary Demo Files

and check gpios iomux settings with jtag using

AN5229 ARM DS-5 Development Studio Debug i.MX6UL-EVK

https://www.nxp.com/docs/en/application-note/AN5229.pdf 

Best regards
igor
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[zhangbin_eos]

Hi igor,

  The problem has been resolved.It's really an gpios iomux settings problem.

  By setting the IOMUXC_SW_MUX_CTL register, I modified the mode of the pins.

  I have a problem,How to set LCD_DATA00-23  to GPIO mode in DTS file?

Best regards

zb