Hi,
I’m trying to read Volume Up button status in a yocto linux distro without X.
I figured out on my carrier the GPIO pin is 313
# cat /sys/kernel/debug/gpio
gpiochip2: GPIOs 248-255, parent: platform/max77620-gpio, max77620-gpio, can sleep:
gpio-248 ( |external-connection:) in hi
gpio-253 ( |spmic_gpio_input ) in lo
gpio-254 ( |spmic_gpio_input ) in hi
gpiochip1: GPIOs 256-319, parent: platform/c2f0000.gpio, tegra-gpio-aon:
gpio-272 ( |temp-alert ) in hi
gpio-312 ( |Power ) in hi
gpio-313 ( |Volume Up ) in hi
gpio-314 ( |Volume Down ) in hi
gpio-315 ( |wifi-wake-ap ) in hi
gpio-316 ( |bt_host_wake ) in hi
If I try to export GPIO pin 313 I get a Busy device error.
I need to read the state, not react to an event.
Thanks,