Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Stefan Roese <sr@denx.de>

WATCHDOG_RESET is no more. Replace the reference by schedule().

While here, rearrange the sentence a bit so that "cyclic_run()"
becomes the object and "the main function responsible for calling all
registered cyclic functions" a parenthetical rather than the other way
around, which at least to me makes it more readable.

Signed-off-by: Rasmus Villemoes <ravi@prevas.dk>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Stefan Roese <sr@denx.de>

There are of course not a whole lot of examples in-tree yet, but
before they appear, let's make this API change: Instead of separately
allocating a 'struct cyclic_info', make the users embed such an
instance in their own structure, and make the convention that the
callback simply receives the 'struct cyclic_info *', from which the
clients can get their own data using the container_of() macro.

This has a number of advantages.

First, it means cyclic_register() simply cannot fail, simplifying the
code. The necessary storage will simply be allocated automatically
when the client's own structure is allocated (often via
uclass_priv_auto or similar).

Second, code for which CONFIG_CYCLIC is just an option can more easily
be written without #ifdefs, if we just provide an empty struct
cyclic_info {}. For example, the nested CONFIG_IS_ENABLED()s in
https://lore.kernel.org/u-boot/20240316201416.211480-1-marek.vasut+renesas@mailbox.org/
are mostly due to the existence of the 'struct cyclic_info *' member
being guarded by #ifdef CONFIG_CYCLIC.

And we do probably want to avoid the extra memory overhead of that
member when !CONFIG_CYCLIC. But that is automatic if, instead of a
'struct cyclic_info *', one simply embeds a 'struct cyclic_info',
which will have size 0 when !CONFIG_CYCLIC. Also, the no-op
cyclic_register() function can just unconditionally be called, and the
compiler will see that (1) the callback is referenced, so not emit a
warning for a maybe-unused function and (2) see that it can actually
never be reached, so not emit any code for it.

Reviewed-by: Stefan Roese <sr@denx.de>
Signed-off-by: Rasmus Villemoes <rasmus.villemoes@prevas.dk>

Cyclic now just print a warning once instead of disabling the cyclic
function when the cyclic function upon exceeding CPU time usage.

Fixes: ddc8d36a7455 ("cyclic: Don't disable cylic function upon exceeding CPU time")
Signed-off-by: Weizhao Ouyang <o451686892@gmail.com>

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

Add documentation for the cyclic function infrastructure, including the
cyclic command.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>