clk: allow to instanciate clk gate without registering it ...

Allows to reuse the clk gate code within other clocks.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: add clock lookup from devicetree ...

Taken from the Linuxkernel with some small adjustments for barebox.

Signed-off-by: Lucas Stach <dev@lynxeye.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: add prototype for clk_is_enabled ...

On MXS we need to poll the busy bit when changing a clock rate, but only
when the parent clocks are enabled. This exposes the already present
function clk_is_enabled which is suitable for this job.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: gate: Add inverted gate support ...

This adds support for gates which need 0 to enable.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: divider: Add onebased divider support ...

In some dividers the register value matches the divider value. This
patch adds support for them.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: Add is_enabled callback ...

This allows us to better detect whether a clk is enabled or not.

- If we can ask a clk, ask it. If it's enabled, go on and ask parents
- If we can't ask it, but it can be enabled, depend on the enable_count.
  if it's positive, go on and ask parents
- If we can't ask it and it cannot be enabled, assume it is enabled
  and ask parents.

This makes the CLK_ALWAYS_ENABLED unnecessary, since the fixed clk now
always returns 1 in its is_enabled callback.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Merge branch 'pu/clk' into for-next/clk ...

Conflicts:
	include/linux/clk.h

clk: Add clk table based divider support ...

For easy support of table based dividers.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: add always enabled clocks ...

Current barebox clk framework allow disable any clock
and there is no means to prevent that.

But there are the clocks that can't be disabled
by software at all.

This patch allow registration of a clock immune to clk_disable().

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: Add clk gate support ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clk: initial common clk support ...

This adds barebox common clk support loosely based on the Kernel common
clk support. differences are:

- barebox does not need prepare/unprepare
- no parent rate propagation for set_rate
- struct clk is not really encapsulated from the drivers

Along with the clk support we have support for some basic clk building
blocks:

- clk-fixed
- clk-fixed-factor
- clk-mux
- clk-divider

clk-fixed and clk-fixed-factor are completely generic, clk-mux and clk-divider
are currently the way i.MX muxes/dividers are implemented.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

clock: Introduce clock framework from Linux ...

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>