Implement the restore_context() operation to restore the clock rate and the
clock parent state. The clock rate is saved in sci_clk struct during
set_rate() operation. The parent index is saved in sci_clk struct during
set_parent() operation. During clock registration, the core retrieves each
clock’s parent using get_parent() operation to ensure the internal clock
tree reflects the actual hardware state, including any configurations made
by the bootloader. So we also save the parent index in get_parent().

Signed-off-by: Thomas Richard (TI.com) <thomas.richard@bootlin.com>
---
 drivers/clk/keystone/sci-clk.c | 42 ++++++++++++++++++++++++++++++++++--------
 1 file changed, 34 insertions(+), 8 deletions(-)

diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
index 9d5071223f4cb..428050a05de31 100644
--- a/drivers/clk/keystone/sci-clk.c
+++ b/drivers/clk/keystone/sci-clk.c
@@ -47,6 +47,8 @@ struct sci_clk_provider {
  * @node:	 Link for handling clocks probed via DT
  * @cached_req:	 Cached requested freq for determine rate calls
  * @cached_res:	 Cached result freq for determine rate calls
+ * @parent_id:	 Parent index for this clock
+ * @rate:	 Clock rate
  */
 struct sci_clk {
 	struct clk_hw hw;
@@ -58,6 +60,8 @@ struct sci_clk {
 	struct list_head node;
 	unsigned long cached_req;
 	unsigned long cached_res;
+	u8 parent_id;
+	unsigned long rate;
 };
 
 #define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw)
@@ -210,10 +214,16 @@ static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate,
 			    unsigned long parent_rate)
 {
 	struct sci_clk *clk = to_sci_clk(hw);
+	int ret;
+
+	ret = clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
+					   clk->clk_id, rate / 10 * 9, rate,
+					   rate / 10 * 11);
 
-	return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
-					    clk->clk_id, rate / 10 * 9, rate,
-					    rate / 10 * 11);
+	if (!ret)
+		clk->rate = rate;
+
+	return ret;
 }
 
 /**
@@ -237,9 +247,9 @@ static u8 sci_clk_get_parent(struct clk_hw *hw)
 		return 0;
 	}
 
-	parent_id = parent_id - clk->clk_id - 1;
+	clk->parent_id = (u8)(parent_id - clk->clk_id - 1);
 
-	return (u8)parent_id;
+	return clk->parent_id;
 }
 
 /**
@@ -252,12 +262,27 @@ static u8 sci_clk_get_parent(struct clk_hw *hw)
 static int sci_clk_set_parent(struct clk_hw *hw, u8 index)
 {
 	struct sci_clk *clk = to_sci_clk(hw);
+	int ret;
 
 	clk->cached_req = 0;
 
-	return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
-					      clk->clk_id,
-					      index + 1 + clk->clk_id);
+	ret = clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
+					     clk->clk_id,
+					     index + 1 + clk->clk_id);
+	if (!ret)
+		clk->parent_id = index;
+
+	return ret;
+}
+
+static void sci_clk_restore_context(struct clk_hw *hw)
+{
+	struct sci_clk *clk = to_sci_clk(hw);
+
+	sci_clk_set_parent(hw, clk->parent_id);
+
+	if (clk->rate)
+		sci_clk_set_rate(hw, clk->rate, 0);
 }
 
 static const struct clk_ops sci_clk_ops = {
@@ -269,6 +294,7 @@ static const struct clk_ops sci_clk_ops = {
 	.set_rate = sci_clk_set_rate,
 	.get_parent = sci_clk_get_parent,
 	.set_parent = sci_clk_set_parent,
+	.restore_context = sci_clk_restore_context,
 };
 
 /**

-- 
2.51.0

On 12/5/2025 7:58 PM, Thomas Richard (TI.com) wrote:
> Implement the restore_context() operation to restore the clock rate and the
> clock parent state. The clock rate is saved in sci_clk struct during
> set_rate() operation. The parent index is saved in sci_clk struct during
> set_parent() operation. During clock registration, the core retrieves each
> clock’s parent using get_parent() operation to ensure the internal clock
> tree reflects the actual hardware state, including any configurations made
> by the bootloader. So we also save the parent index in get_parent().
>
> Signed-off-by: Thomas Richard (TI.com) <thomas.richard@bootlin.com>
> ---
>   drivers/clk/keystone/sci-clk.c | 42 ++++++++++++++++++++++++++++++++++--------
>   1 file changed, 34 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/clk/keystone/sci-clk.c b/drivers/clk/keystone/sci-clk.c
> index 9d5071223f4cb..428050a05de31 100644
> --- a/drivers/clk/keystone/sci-clk.c
> +++ b/drivers/clk/keystone/sci-clk.c
> @@ -47,6 +47,8 @@ struct sci_clk_provider {
>    * @node:	 Link for handling clocks probed via DT
>    * @cached_req:	 Cached requested freq for determine rate calls
>    * @cached_res:	 Cached result freq for determine rate calls
> + * @parent_id:	 Parent index for this clock
> + * @rate:	 Clock rate
>    */
>   struct sci_clk {
>   	struct clk_hw hw;
> @@ -58,6 +60,8 @@ struct sci_clk {
>   	struct list_head node;
>   	unsigned long cached_req;
>   	unsigned long cached_res;
> +	u8 parent_id;
> +	unsigned long rate;
>   };
>   
>   #define to_sci_clk(_hw) container_of(_hw, struct sci_clk, hw)
> @@ -210,10 +214,16 @@ static int sci_clk_set_rate(struct clk_hw *hw, unsigned long rate,
>   			    unsigned long parent_rate)
>   {
>   	struct sci_clk *clk = to_sci_clk(hw);
> +	int ret;
> +
> +	ret = clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
> +					   clk->clk_id, rate / 10 * 9, rate,
> +					   rate / 10 * 11);
>   
> -	return clk->provider->ops->set_freq(clk->provider->sci, clk->dev_id,
> -					    clk->clk_id, rate / 10 * 9, rate,
> -					    rate / 10 * 11);
> +	if (!ret)
> +		clk->rate = rate;
> +
> +	return ret;
>   }
>   
>   /**
> @@ -237,9 +247,9 @@ static u8 sci_clk_get_parent(struct clk_hw *hw)
>   		return 0;
>   	}
>   
> -	parent_id = parent_id - clk->clk_id - 1;
> +	clk->parent_id = (u8)(parent_id - clk->clk_id - 1);
>   
> -	return (u8)parent_id;
> +	return clk->parent_id;
>   }
>   
>   /**
> @@ -252,12 +262,27 @@ static u8 sci_clk_get_parent(struct clk_hw *hw)
>   static int sci_clk_set_parent(struct clk_hw *hw, u8 index)
>   {
>   	struct sci_clk *clk = to_sci_clk(hw);
> +	int ret;
>   
>   	clk->cached_req = 0;
>   
> -	return clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
> -					      clk->clk_id,
> -					      index + 1 + clk->clk_id);
> +	ret = clk->provider->ops->set_parent(clk->provider->sci, clk->dev_id,
> +					     clk->clk_id,
> +					     index + 1 + clk->clk_id);
> +	if (!ret)
> +		clk->parent_id = index;
> +
> +	return ret;
> +}
> +
> +static void sci_clk_restore_context(struct clk_hw *hw)
> +{
> +	struct sci_clk *clk = to_sci_clk(hw);
> +
> +	sci_clk_set_parent(hw, clk->parent_id);
> +
> +	if (clk->rate)
> +		sci_clk_set_rate(hw, clk->rate, 0);


Mostly looks ok ,  Please add some warning prints in case of resume path 
either of

sci_clk_set_parent/sci_clk_set_rate returned failure


>   }
>   
>   static const struct clk_ops sci_clk_ops = {
> @@ -269,6 +294,7 @@ static const struct clk_ops sci_clk_ops = {
>   	.set_rate = sci_clk_set_rate,
>   	.get_parent = sci_clk_get_parent,
>   	.set_parent = sci_clk_set_parent,
> +	.restore_context = sci_clk_restore_context,
>   };
>   
>   /**
>