clk: mediatek: add CLK_PARENT_EXT

Add support for external clock parent type in MediaTek clock driver to
allow multiple external clock sources.

This is intended to eventually replace CLK_PARENT_XTAL which only allows
a single external clock source. Replacing CLK_PARENT_XTAL is not trivial
since it would required touching all chip-specific drivers. So that is
saved for another day.

Before this change, the only way to add additional external clocks was
to use a clock ID mapping and add the external clock in the fixed clocks
portion of the CLK_PARENT_TOPCKGEN clocks. After this change, such hacks
are no longer necessary and external clocks can be added in a cleaner
way.

Reviewed-by: Julien Stephan <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: David Lechner <[email protected]>

0 files changed, 0 insertions, 0 deletions