The clock-tree contains clocks that should never get disabled automatically.
One example are the base ACLKs, the base supplies for all peripherals.

Therefore add a structure similar to the sunxi clock-tree to protect these
special clocks from being disabled.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Tested-by: NDoug Anderson <dianders@chromium.org>
Tested-by: NKever Yang <kever.yang@rock-chips.com>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

It is only used locally in clk/rockchip/clk.c and thus can be static.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

Rockchip SoCs may provide fraction dividers for some clocks, mostly for
i2s and uarts. In contrast to the other registers, these do not use
the hiword-mask paradigm, but instead split the register into the upper
16 bit for the nominator and the lower 16 bit for the denominator.

The common clock framework got a generic fractional divider clock type
recently that can accomodate this setting easily. All currently known
fraction dividers have a separate gate too, therefore implement the
divider as composite using the ops-struct from fractional_divider clock
and add the gate if necessary.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

All known Rockchip SoCs down to the RK28xx (ARM9) use a similar pattern to
handle their plls:
                       |--\
xin32k ----------------|mux\
xin24m -----| pll |----|pll|--- pll output
       \---------------|src/
                       |--/

The pll output is sourced from 1 of 3 sources, the actual pll being one of
them. To change the pll frequency it is imperative to remux it to another
source beforehand. This is done by adding a clock-listener to the pll that
handles the remuxing before and after the rate change.

The output mux is implemented as a separate clock to make use of already
existing common-clock features for disabling the pll if one of the other
two sources is used.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Acked-By: NMax Schwarz <max.schwarz@online.de>
Tested-By: NMax Schwarz <max.schwarz@online.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>

This adds infrastructure for registering clock branches. On Rockchip SoCs
most clock branches are a combination of mux,divider and gate components,
thus a composite clock is used when appropriate.

Clock branches are supposed to be declared in an array using the COMPOSITE*
or MUX, etc makros defined in the header and then registered using
rockchip_clk_register_branches.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Acked-By: NMax Schwarz <max.schwarz@online.de>
Tested-By: NMax Schwarz <max.schwarz@online.de>
Signed-off-by: NMike Turquette <mturquette@linaro.org>