I am trying to use pin SODIMM_101 as a GPIO. It needs to be pulled up at boot and stay high. I have read the following link.
I have attached a screen shot from a scope of what I am seeing.
- CH2 is 3.3V connected at X37 pin 3.
- CH3 is SODIMM_101 connected at X22 pin 7.
- CH4 is RESET_OUT# connected at X3 pin B32.
I am also staying in uboot and not booting into Linux to ease the debug process.
Per the scope image, when Colibri SOM comes out of reset, it acts like I expect it to as the pad at reset is configured as an input and 100k pull-up. Then about 10ms later it goes low and stays low for around 120ms. After that uboot seems to then pull the pin up. I also have a “strong” 10k pull-up attached as an extra precaution.
The colibri_imx6.c file is attached and the pad is defined as WEAK_PULLUP on line 218. Do you know a reason why the GPIO pin is low for 120ms?