clk: Introduce clk_has_parent()
authorThierry Reding <treding@nvidia.com>
Wed, 21 Jan 2015 16:13:00 +0000 (17:13 +0100)
committerMichael Turquette <mturquette@linaro.org>
Sun, 25 Jan 2015 00:56:55 +0000 (16:56 -0800)
commit4e88f3de89fbb7b5a5a0aca20376b276d26732ac
tree010afff654b43fd252c9b1482b034781a3cbfaa1
parent97bf6af1f928216fd6c5a66e8a57bfa95a659672
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 <linux@arm.linux.org.uk>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Michael Turquette <mturquette@linaro.org>
drivers/clk/clk.c
include/linux/clk.h