These new macros are very similar to their SET_*_PM_OPS() equivalent.
They however differ in the fact that the callbacks they set will always
be seen as referenced by the compiler. This means that the callback
functions don't need to be wrapped with a #ifdef CONFIG_PM guard, or
tagged with __maybe_unused, to prevent the compiler from complaining
about unused static symbols. The compiler will then simply evaluate at
compile time whether or not these symbols are dead code.
The callbacks that are only useful with CONFIG_PM_SLEEP is enabled, are
now also wrapped with a new pm_sleep_ptr() macro, which is inspired from
pm_ptr(). This is needed for drivers that use different callbacks for
sleep and runtime PM, to handle the case where CONFIG_PM is set and
CONFIG_PM_SLEEP is not.
These macros are similar to the functions they were created to replace,
with the following differences:
- They use the new macros introduced above, and as such always
reference the provided callback functions.
- They are not tagged with __maybe_unused. They are meant to be used
with pm_ptr() or pm_sleep_ptr() for DEFINE_UNIVERSAL_DEV_PM_OPS()
and DEFINE_SIMPLE_DEV_PM_OPS() respectively.
- They declare the symbol static, since every driver seems to do that
anyway; and if a non-static use-case is needed an indirection pointer
could be used.
The point of this change, is to progressively switch from a code model
where PM callbacks are all protected behind CONFIG_PM guards, to a code
model where the PM callbacks are always seen by the compiler, but
discarded if not used.
Signed-off-by: Paul Cercueil <paul@crapouillou.net> Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>