BeagleBoardXM RevA/B expansion port pins configured as GPIO input not working while the same pin configured as output works


I am facing problem with reading the value of the pin when it is configured as GPIO (input) on the Expasion Connection pin McBSP1_FSR (configured to GPIO #157 in uboot). The value returned is not changing irrespective of the voltage input i.e., 1.8V or GND. If i configure the same gpio#157 as “output” I am able to toggle its level to HIGH and LOW properly. Problem is only with reading in input mode.

Other configuration i did on the system -
Taken McSPI4 (master mode) on P9 (Expansion Connector); the SPI signals are fine as I am able to communicate the external slave processor.

What could be the reason for this behavior?

Below is software information

Hi Sanjeev Kumar
did you resolved your problem ?

Hi Sanjeev Kumar
did you resolved your problem ?

mount -t debugfs none /sys/kernel/debug
cat /sys/kernel/debug/omap-gpio/board (or something like that, I don't
recall exactly)

The idea is to check what the pinmux setting of that pin is.

Hi Jason,
in fact (on my beagleboard-xm) i can only use

with the input mode, it works very well.