GPIO available to use

Products Support DragonBoard410c
#1

From the doc “DragonBoard_HardwareManual.pdf” , I noticed that there are 12 GPIO being mapped in 410c board (GPIO_A to GPIO_L).

I loaded the Debian onto the board,
how could I check any being used by Linux kernel / drivers or User space (application) ?

Adding GPIOs to dts
#2

If you have the libgpiod tools installed (sudo apt install gpiod) then you can look at the GPIO status using gpioinfo. For example:

# List gpio devices
gpiodetect

# Show APQ GPIO status
gpioinfo 1000000.pinctrl

# Show PM GPIO status (counting starts from 1 in the hardware manual
# so subtract 1 for PM GPIO numbers
gpioinfo 200f000.spmi:pm8916@0:gpios@c00

# Show MPP GPIO status (subtract 1 for MPP GPIO numbers too)
gpioinfo 200f000.spmi:pm8916@0:gpios@c00

You can also use the libgpiod to manipulate the GPIO status from shell (gpiod tools) or C (libgpiod).

PS You can also use MRAA as a wrapper library instead: MRAA Library for 96Boards - 96Boards