This adds a helper function for clk_get_by_name in cases where the clock is
optional. Hopefully this helps point driver writers in the right direction.
Also convert some existing users.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20220115205247.566210-2-seanga2@gmail.com

This converts the existing client (aka clk.h) documentation to kernel doc
format, and adds it to the HTML docs. I have tried to preserve existing
comments as much as possible, refraining from semantic changes.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20211222171114.3091780-4-seanga2@gmail.com
[rebased onto u-boot/master and resolved conflicts]
Signed-off-by: Sean Anderson <seanga2@gmail.com>

The optional varients of clk_get_* functions are just simple wrappers.
Reduce code size a bit by inlining them. On platforms where it is not used
(most of them), it will not be compiled in any more. On platforms where
they are used, the inlined branch should not cause any significant growth.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20211222171114.3091780-3-seanga2@gmail.com

This normalizes the name of this accessor function to put "_optional" last.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Link: https://lore.kernel.org/r/20211222171114.3091780-2-seanga2@gmail.com

Sphinx expects Return: and not @return to indicate a return value.

find . -name '*.c' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

find . -name '*.h' -exec \
sed -i 's/^\(\s\)\*\(\s*\)@return\(\s\)/\1*\2Return:\3/' {} \;

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

Improve clk_get_rate() @return documentation that otherwise is a bit
ambiguous. At the moment I expect to return 0 as error since the return
type is 'ulong', instead the function really returns negative value in
case the corresponding function pointer is null and returns 0 if the clock
is invalid.

Signed-off-by: Giulio Benetti <giulio.benetti@benettiengineering.com>
Reviewed-by: Sean Anderson <seanga2@gmail.com>

This is actually a misnomer now, since the phandle info may contain
a driver_info index or a udevice index. Rename it to use the word
'phandle', which seems more accurate. Add a comment while we are here.

Also add a test for this function.

Signed-off-by: Simon Glass <sjg@chromium.org>

Use this new Kconfig to simplify the compilation conditions where
appropriate.

Signed-off-by: Simon Glass <sjg@chromium.org>

Since 291da96b8e ("clk: Allow clock defaults to be set during re-reloc
state for SPL only") it has been impossible to set clock defaults before
relocation. This is annoying on boards without SPL, since there is no way
to set clock defaults before U-Boot proper. In particular, the aisram rate
must be changed before relocation on the K210, since U-Boot will hang if we
try and change the rate while we are using aisram.

To get around this, extend the stage parameter to allow force setting
defaults, even if they would be otherwise postponed for later. A device
tree property was decided against because of the concerns in the original
commit thread about the overhead of repeatedly parsing the device tree.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

It returns the rate which will be set if you ask clk_set_rate() to set
that rate. It provides a way to query exactly what rate you'll get if
you call clk_set_rate() with that same argument.
So essentially, clk_round_rate() and clk_set_rate() are equivalent
except the former does not modify the clock hardware in any way.

Signed-off-by: Dario Binacchi <dariobin@libero.it>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Sean Anderson <seanga2@gmail.com>