Is there an easy way to set some arbitrary value to a GPIO output? It seems that on Beagleboard xM the GPIOs are coming up HIGH by default, and we have a buzzer attached to GPIO_137, which is buzzing the heck out of us until the kernel is fully up, and we can switch it off by software.
I prepended the U-Boot boot command with “gpio clear 137”, which does silence the buzzer for a couple of seconds, then the kernel begins to boot, and the buzzer comes back up (the kernel switches it to 1 on startup?). I assume there must be a way to set the value to a specific register via the DTS?
This is a standard setup of Robert C. Nelson’s Ubuntu demo image.
Thanks!