This is a CentOS 7 kernel src.rpm with configs and bonus patches to enable additional functionality on Soekris net6501 hardware.

Right now, the patches are:

• e6xx-force-hpet.patch: Force-enable the high-precision event timer on E6xx systems that don't support ACPI (unknown origin)
• soekris-net6501.patch: All the magic for everything else

The patches should be applyable to most any kernel tree, but definitely applies cleanly to the kernel in this repository.

The parts of soekris-net6501.patch:

• soekris-net6501.c: The platform driver for the other modules. It sets up the LED and GPIO device entries used by the other modules
• leds-net6501.c: Courtesy aptivate, this module sets up two devices under /sys/class/leds as net6501:green:ready and net6501:red:error
• gpio-ioport.c: A generic GPIO device set up to handle IO port based devices. It is largely identical to gpio-generic.c (or gpio-mmio.c in modern kernels), and could probably be merged with that without much effort. On stock net6501 devices, it will create /sys/class/gpio/gpiochip240, which can export gpio240 - gpio255

Other notes:

• You will want to load all three modules. Order shouldn't matter.
• I'm not sure if I should give the GPIO devices a lower number (I think gpiochip14), or let it get dynamically alocated as it currently is.
• As far as I know, the net6501 does not have interrupt functionality on the GPIO device. If someone knows differently, please let me know!
• It has been on the order of a decade since I've done any real kernel work. Don't use anything here as a model on how to do, well, anything. I will glady accept corrections, complaints, or improvements!
• Also, if this code blows up and reformats your house, don't blame me. Use at your own risk!

Usage examples, once modules are loaded:

# Turn error light on
$ echo 1 > /sys/class/leds/net6501:red:error/brightness

# Make error light heartbeat
$ modprobe ledtrig-heartbeat
$ echo heartbeat > /sys/class/leds/net6501:red:error/trigger

# Our generic GPIO handler
$ cat /sys/class/gpio/gpiochip240/label
basic-ioport-gpio

# Number of GPIO lines
$ cat /sys/class/gpio/gpiochip240/ngpio
16

# Export a GPIO line (will create /sys/class/gpio/gpioN
$ echo 240 > /sys/class/gpio/export

$ cat /sys/class/gpio/gpio240/direction
in

# I think these may have a weak pullup on them, since the value reads '1'
# even when nothing is connected, and my meter reads ~3.25v
$ cat /sys/class/gpio/gpio240/value
1

$ echo out > /sys/class/gpio/gpio240/direction

# Meter reads 0v after this
$ cat /sys/class/gpio/gpio240/value
0

# Meter reads 3.25v after this
$ echo 1 > /sys/class/gpio/gpio240/value

Comments/complaints/recommendations for good heavy metal to: J. Grizzard [email protected]