[rpi] Adds basic support for GPIO on Raspberry Pi boards

[henrikssn]

The purpose of this is to simplify driver development, using bitbang SPI&I2C on the RPi.

It is essentially just a wrapper around WiringPi.

[salkinium]

Nice job! I didn't expect so few changes to get this to work, but then again Linux is doing all the heavy lifting here.

[henrikssn]

Nice job! I didn't expect so few changes to get this to work, but then again Linux is doing all the heavy lifting here.

Thanks! Yeah, it is mostly Linux and WiringPi which solved the hard stuff, this is mostly a wrapper... Anyway, I tested the BitBangSPI implementation with this and that worked fine. Might be the easiest way to run hardware driver tests (if we ever get to setting up a CI for that)

[rleh]

https://circleci.com/gh/modm-io/modm/20845:

python3 tools/scripts/synchronize_docs.py -d

git diff
diff --git a/README.md b/README.md
index 79a9df804..eaf76f7d4 100644
--- a/README.md
+++ b/README.md
@@ -157,6 +157,7 @@ documentation.
 <td align="center">NUCLEO-L476RG</td>
 <td align="center">OLIMEXINO-STM32</td>
 </tr><tr>
+<td align="center">RASPBERRYPI-4</td>
 <td align="center">SAMD21-MINI</td>
 <td align="center">STM32F030F4P6-DEMO</td>
 </tr>

Please synchronize the modm documentation:

    $ python3 tools/scripts/synchronize_docs.py

and then commit the results!

Changes required

[henrikssn]

Ready to merge

[rleh]

Could you squash and rebase your commits?

[salkinium]

I’ll rebase/merge it later.

[salkinium]

I’ll rebase/merge it later.

Restructured commits and fixed a small refactoring bug, I'll merge once the CI passes.