In the day I did:
config-pin P9_11 out
to make it a gpio output. Now it appears I have to do:
config-pin P9_11 gpio
But how do I make it an output? Must I do:
echo out > /sys/class/gpio/gpio30/direction ?
–Mark
The concept of out/in is not currently supported in the c based
re-write of config-pin used in Buster..
https://github.com/beagleboard/bb.org-overlays/tree/master/tools/pmunts_muntsos
Regards,
So is,
echo out > /sys/class/gpio/gpio30/direction
The proper way to set it to output?
–Mark
The proper way is to use libgpiod tools such as gpioset 
sudo gpioset gpiochip0 30=1
But that old way still woks.
Regards,
Well, my solution, for now, was to write a wrapper[1] for config-pin that uses gpioinfo when ‘in’ or ‘out’ are used.
–Mark
[1] https://github.com/MarkAYoder/PRUCookbook/blob/v2.0/docs/common/config-pin.sh
The proper way is to use libpruio and do pinmuxing single source in the code
pruio_gpio_setValue(io, P9_11, [0,1]);
Regards
How does the library change the pinmux during runtime?
Does it use /sys/devices/platform/ocp/ocp:P9_11_pinmux/state? (which
is created by bone-pinmux-helper)
thanks,
drew
The GPIO utils in FPP use a combination of /sys/devices/platform/ocp/ocp:%s_pinmux/state and /sys/class/gpio/gpio%u/ locations to configure the pin in various ways. See:
https://github.com/FalconChristmas/fpp/blob/master/src/util/BBBUtils.cpp#L228
Some of it is a bit complex as some pins may need to boot up in i2c mode but then be flipped to gpio/out.
The idea of using libgpiod is “ok” but doesn’t allow configuring the internal pull ups for the input (at least until kernel 5.4 and a newer version of libgpiod)
Dan
It contains a LKM (loadable kernel module) that can set any pin configuration (ie. PRU-GPIO with pull-[up,down] at SD card slot) at run-time. All members of system group “pruio” have pinmuxing access from user space. This concept saves lots of kernel memory and more than six seconds boot-time.
Check out the documentation.
Regards