Working on 4.x kernels

[nofxx]

Hello @notnyt , thank you for this great gem. I'm trying make it all works on newer kernels. So far got some tested, pwm had most changes. Tests:

• [x] GPIO - Out
• [x] GPIO - In need to test edge detections too
• [x] AIN - need to recheck, think I loaded the overlay manually
• [x] PWM - lots of changes, but working now... not sure all those overlays and if 'pwmchipN' is ok
• [x] I2C - connected to an avr
• [ ] SPI
• [ ] UART

Gonna find out all the changes, and add some IF's later, as now I marked all as '# OLD' https://github.com/nofxx/beaglebone.git Thanks again!

Testing on archarm, but even debian, the distro for the 80s is coming with ruby 2+ now. Don't expect 2.1+ tho, they have a "reputation" to maintain. So I also cleanup and changes to ruby 2+.

[notnyt]

Are there any code changes in the 'clean up' commit?

Is 4.x the default kernel for the latest bbb images?

[nofxx]

@notnyt I made kinda of fuzz. 'clean up' was only rubocop's, but it freezed two constants that were changing in code. So end up like: clean up | actual pwm changes | clean up fixes.

On arch 4.9.x is default, legacy kernel is no more. Not sure in debian, will install to check.

EDIT: Also on the clean up the 'beaglebone.rb' file has just some style changes, was sleepy shouldn't commited it. The raise 'Install dtc' is a helper but should read if `which dtc`.empty? It's pretty confusing error, it'll say slots file isn't writable while the problem is the dtc compile.