#21 Add Raspberry Pi 2 support to existing HD44780-rpi driver

[Paul Webster]

Raspberry Pi 2 has moved the mapped base address of peripherals.
So instead of having it hard-coded via a define, it is now necessary to detect RPi type and store address as a variable.

There is a new routine from RPi FOundation to help with this - but it appears to depend on Device Tree support which, if correct, means that it would not work on old versions of the OS.
This patch determine RPi version based on info found in /proc/cpuinfo.
It might not work for future versions of RPi but we are not in the future yet.

[Paul Webster]

Modified to try to get the GPIO base address from /proc/iomem first - which should make it more future proof.
There is a risk that new text strings or syntax could appear in /proc/iomem that break things - but hopefully that will not happen.
If the strings are not found then uses hardware info to pick one of 2 pre-defined addresses (as in previous patch).

[jagdeep Sharma]

Guyz, could you please be able to share modified files for rpi2. I tried to change drivers based on diff files but no luck.

Thanks

[Paul Webster]

Not sure what the rules are for putting binaries here ... so I can understand if someone deletes this.
However, here is my built version - note this is built to support HD44780 on RPi only.
Make sure that you set the permissions to be the same as your pre-existing copy.

[jagdeep Sharma]

Hi Paul,

thank you so much. I can confirm that it is working fine with RPi2 when queried with LCDproc.

[Inonoob]

Hey

I'm a bit struggling with the HD44780 driver. I used to have the HD44780 and the Hifiberry digi working together on the RPI b+ with Openelec. I bought RPi2. I Installed Openelec and activate the Hifiberry Digi by going into /flash/config.txt . In this file you active the Hifiberry Digi by putting "dtoverlay=hifiberry-Digi". So after this i tried the HD44780 and nothing. So i look for help and found this thread. I tried the new HD44780 driver but when i try to load it the Hifiberry is shutdown no sound and the HD44780 is still not working.

So I may ask does the new driver maybe reinitiate the GPIO mapping and by doing disable the Hifiberry Digi.

Would it make sense to add a dtoverlay=HD44780 ?? or what would be the next step

many thanks for your help