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Imx7d sabre, u-boot and GPIO

Question asked by jensalsig on Aug 17, 2016
Latest reply on Aug 17, 2016 by igorpadykov



I'm trying to use one the two switch on the Sabre board in u-boo to select the boot device, either boot from SD-card or network.


But I'm stuck at the gpio part. I'm not able to read the value of either of the switches.


According to Definitive GPIO guide - Studio Kousagi Wiki the iopin number will be 138 for Sw3 (usr_bt1). I know that the source calculates on a imx6 but I assume that the calculations for the iopin is the same on the Imx7

I have tried, in u-boot:

"gpio i 138"

but the value returned is always 0.


I have also browsed through the u-boot code, but I was not able to find anything regarding gpio in the imx7. This leads me to believe that it isn't configured. Is this true? And if not are there any example/guides on how to enable it?