clk: Introduce clk_has_parent()

This new function is similar to clk_set_parent(), except that it doesn't
actually change the parent. It merely checks that the given parent clock
can be a parent for the given clock.

A situation where this is useful is to check that a particular setup is
valid before switching to it. One specific use-case for this is atomic
modesetting in the DRM framework where setting a mode is divided into a
check phase where a given configuration is validated before applying
changes to the hardware.

Cc: Russell King <[email protected]>
Signed-off-by: Thierry Reding <[email protected]>
Reviewed-by: Stephen Boyd <[email protected]>
Signed-off-by: Michael Turquette <[email protected]>

0 files changed, 0 insertions, 0 deletions