mvebu: Device bus driver resurrection

[Ezequiel Garcia]

Hello everyone,

Now that we've all agreed on a mvebu mbus driver (or a first version of it)
I'd like to resurrect the Device Bus driver.

As far as I can remember, the last things said about this driver were:

  * The timing parameters should be in {nano,pico,etc} seconds,
    instead of ticks.

  * Although not everyone agreed, this driver was a good thing to have
    so we no longer depend on the bootloader setting these parameters.
    
  * The address decoding windows should *not* be setup by this driver,
    but rather be described in the device tree itself.

If anyone has aditional comments, please speak your mind.

My plan is to address all of the above comments, and send a v2 soon.

However, since we do not yet describe the address windows at the device tree,
the plan is to do window allocation/release in this devbus driver
**only as a temporal solution**.

Once the address decoding windows are properly described in the DTS,
we can remove that handling from the driver for good.

Does this sound sane enough?
-- 
Ezequiel García, Free Electrons
Embedded Linux, Kernel and Android Engineering
http://free-electrons.com