MFD/OF: document MFD devices and handle simple-mfd

This defines a new compatible option for MFD devices "simple-mfd" that will
make the OF core spawn child devices for all subnodes of that MFD device.
It is optional but handy for things like syscon and possibly other
simpler MFD devices.

Since there was no file to put the documentation in, I took this opportunity
to make a small writeup on MFD devices and add the compatible definition
there.

Suggested-by: Lee Jones <[email protected]>
Acked-by: Lee Jones <[email protected]>
Acked-by: Antoine Tenart <[email protected]>
Acked-by: Alexandre Belloni <[email protected]>
Cc: Arnd Bergmann <[email protected]>
Cc: Devicetree <[email protected]>
Cc: Rob Herring <[email protected]>
Cc: Benjamin Herrenschmidt <[email protected]>
Cc: Grant Likely <[email protected]>
Cc: Pawel Moll <[email protected]>
Cc: Mark Rutland <[email protected]>
Cc: Ian Campbell <[email protected]>
Cc: Kumar Gala <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>

0 files changed, 0 insertions, 0 deletions