[RFC/RFT v2 02/14] clk: core: introduce clk_hw_set_parent()

From: Neil Armstrong
Date: Wed Jun 26 2019 - 05:07:56 EST

Introduce the clk_hw_set_parent() provider call to change parent of
a clock by using the clk_hw pointers.

This eases the clock reparenting from clock rate notifiers and
implementing DVFS with simpler code avoiding the boilerplates
functions as __clk_lookup(clk_hw_get_name()) then clk_set_parent().

Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
drivers/clk/clk.c | 6 ++++++
include/linux/clk-provider.h | 1 +
2 files changed, 7 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index aa51756fd4d6..06e1abe3391c 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2490,6 +2490,12 @@ static int clk_core_set_parent_nolock(struct clk_core *core,
return ret;

+int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *parent)
+ return clk_core_set_parent_nolock(hw->core, parent->core);
* clk_set_parent - switch the parent of a mux clk
* @clk: the mux clk whose input we are switching
diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h
index bb6118f79784..8a453380f9a4 100644
--- a/include/linux/clk-provider.h
+++ b/include/linux/clk-provider.h
@@ -812,6 +812,7 @@ unsigned int clk_hw_get_num_parents(const struct clk_hw *hw);
struct clk_hw *clk_hw_get_parent(const struct clk_hw *hw);
struct clk_hw *clk_hw_get_parent_by_index(const struct clk_hw *hw,
unsigned int index);
+int clk_hw_set_parent(struct clk_hw *hw, struct clk_hw *new_parent);
unsigned int __clk_get_enable_count(struct clk *clk);
unsigned long clk_hw_get_rate(const struct clk_hw *hw);
unsigned long __clk_get_flags(struct clk *clk);