2019-06-20 15:00:54

by Neil Armstrong

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

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 <[email protected]>
---
drivers/clk/clk.c | 5 +++++
include/linux/clk-provider.h | 1 +
2 files changed, 6 insertions(+)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
index aa51756fd4d6..3e98f7dec626 100644
--- a/drivers/clk/clk.c
+++ b/drivers/clk/clk.c
@@ -2490,6 +2490,11 @@ 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);
--
2.21.0

2019-06-25 20:34:56

by Stephen Boyd

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

Quoting Neil Armstrong (2019-06-20 08:00:01)
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index aa51756fd4d6..3e98f7dec626 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -2490,6 +2490,11 @@ 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);
> +}

Will this be used from a module? Maybe it needs an EXPORT_SYMBOL_GPL().

> +
> /**
> * clk_set_parent - switch the parent of a mux clk
> * @clk: the mux clk whose input we are switching

2019-06-26 08:22:55

by Neil Armstrong

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

On 25/06/2019 22:32, Stephen Boyd wrote:
> Quoting Neil Armstrong (2019-06-20 08:00:01)
>> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
>> index aa51756fd4d6..3e98f7dec626 100644
>> --- a/drivers/clk/clk.c
>> +++ b/drivers/clk/clk.c
>> @@ -2490,6 +2490,11 @@ 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);
>> +}
>
> Will this be used from a module? Maybe it needs an EXPORT_SYMBOL_GPL().

Probably since it's in clk-provider.h

Will add.

>
>> +
>> /**
>> * clk_set_parent - switch the parent of a mux clk
>> * @clk: the mux clk whose input we are switching