pmdomain: core: add genpd_for_each_child() helper

Add a new internal helper function genpd_for_each_child() that recursively
iterates over all devices in a PM domain and its child domains (subdomains).
This helper is useful for governors and other core PM domain code that needs
to examine or apply operations to all devices within a domain hierarchy.

The function takes a callback that is invoked for each device, and supports
early termination if the callback returns a non-zero value.

The helper is defined in a new internal header drivers/pmdomain/core.h and
implemented in drivers/pmdomain/core.c, making it available to other PM
domain subsystem components.

The first user of this helper is the cpu_system_power_down_ok() governor
function, which uses it to check device QoS latency constraints across the
entire domain hierarchy.

Reviewed-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Signed-off-by: Kevin Hilman (TI) <khilman@baylibre.com>
Signed-off-by: Ulf Hansson <ulfh@kernel.org>

0 files changed, 0 insertions, 0 deletions