Some dividers might have a maximum value that is lower than the width of
the register.

Add a field to _ccu_div to handle those case properly. If the field is set
to 0, the code will assume that the maximum value is the maximum one that
can be used with the field register width.

Otherwise, we'll use whatever value has been set.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

The internal _ccu_div structure is meant to be embedded into other
structures to combine the various dividers and to form the clock classes
support.

Start to document those structures by using kerneldoc.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Add some macros to ease the declaration of clocks that are using them.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Acked-by: NChen-Yu Tsai <wens@csie.org>

Rename the internal mux macro to be consistent with the other internal
structure macros.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

Add support for the various dividers (linear, table or pow-of-two based)
found in the CCU.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NMichael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/20160629190535.11855-8-maxime.ripard@free-electrons.com