diff mbox series

[RFCv2,2/8] clk: imx8m-composite: Switch to determine_rate

Message ID 5d62b31309e6402bd9fa608730518b39af823fb3.1561707104.git.leonard.crestez@nxp.com (mailing list archive)
State RFC, archived
Headers show
Series Add imx8mm bus frequency switching | expand

Commit Message

Leonard Crestez June 28, 2019, 7:39 a.m. UTC 
This allows consumers to use min_rate max_rate.

Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
---
 drivers/clk/imx/clk-composite-8m.c | 34 +++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 12 deletions(-)

Comments

Abel Vesa June 28, 2019, 8:45 a.m. UTC | #1 
On 19-06-28 10:39:50, Leonard Crestez wrote:
> This allows consumers to use min_rate max_rate.
> 
> Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
> ---
>  drivers/clk/imx/clk-composite-8m.c | 34 +++++++++++++++++++-----------
>  1 file changed, 22 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c
> index 388bdb94f841..1be82ec08ecd 100644
> --- a/drivers/clk/imx/clk-composite-8m.c
> +++ b/drivers/clk/imx/clk-composite-8m.c
> @@ -45,10 +45,12 @@ static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw,
>  				   divider->flags, PCG_DIV_WIDTH);
>  }
>  
>  static int imx8m_clk_composite_compute_dividers(unsigned long rate,
>  						unsigned long parent_rate,
> +						unsigned long min_rate,
> +						unsigned long max_rate,

You should pass on the req instead of min_rate and max_rate here.

>  						int *prediv, int *postdiv)
>  {
>  	int div1, div2;
>  	int error = INT_MAX;
>  	int ret = -EINVAL;
> @@ -56,11 +58,17 @@ static int imx8m_clk_composite_compute_dividers(unsigned long rate,
>  	*prediv = 1;
>  	*postdiv = 1;
>  
>  	for (div1 = 1; div1 <= PCG_PREDIV_MAX; div1++) {
>  		for (div2 = 1; div2 <= PCG_DIV_MAX; div2++) {
> -			int new_error = ((parent_rate / div1) / div2) - rate;
> +			unsigned long new_rate;
> +			int new_error;
> +
> +			new_rate = ((parent_rate / div1) / div2);
> +			if (new_rate < min_rate || new_rate > max_rate)
> +				continue;
> +			new_error = new_rate - rate;
>  
>  			if (abs(new_error) < abs(error)) {
>  				*prediv = div1;
>  				*postdiv = div2;
>  				error = new_error;
> @@ -69,38 +77,40 @@ static int imx8m_clk_composite_compute_dividers(unsigned long rate,
>  		}
>  	}
>  	return ret;
>  }
>  
> -static long imx8m_clk_composite_divider_round_rate(struct clk_hw *hw,
> -						unsigned long rate,
> -						unsigned long *prate)
> +static int imx8m_clk_composite_divider_determine_rate(struct clk_hw *hw,
> +						       struct clk_rate_request *req)
>  {
>  	int prediv_value;
>  	int div_value;
>  
> -	imx8m_clk_composite_compute_dividers(rate, *prate,
> -						&prediv_value, &div_value);
> -	rate = DIV_ROUND_UP(*prate, prediv_value);
> +	imx8m_clk_composite_compute_dividers(req->rate, req->best_parent_rate,
> +					     req->min_rate, req->max_rate,
> +					     &prediv_value, &div_value);
>  
> -	return DIV_ROUND_UP(rate, div_value);
> +	req->rate = DIV_ROUND_UP(req->best_parent_rate, prediv_value);
> +	req->rate = DIV_ROUND_UP(req->rate, div_value);
>  
> +	return 0;
>  }
>  
>  static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw,
> -					unsigned long rate,
> -					unsigned long parent_rate)
> +						unsigned long rate,
> +						unsigned long parent_rate)
>  {
>  	struct clk_divider *divider = to_clk_divider(hw);
>  	unsigned long flags = 0;
>  	int prediv_value;
>  	int div_value;
>  	int ret;
>  	u32 val;
>  
>  	ret = imx8m_clk_composite_compute_dividers(rate, parent_rate,
> -						&prediv_value, &div_value);
> +						   0, ULONG_MAX,
> +						   &prediv_value, &div_value);
>  	if (ret)
>  		return -EINVAL;
>  
>  	spin_lock_irqsave(divider->lock, flags);
>  
> @@ -117,11 +127,11 @@ static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw,
>  	return ret;
>  }
>  
>  static const struct clk_ops imx8m_clk_composite_divider_ops = {
>  	.recalc_rate = imx8m_clk_composite_divider_recalc_rate,
> -	.round_rate = imx8m_clk_composite_divider_round_rate,
> +	.determine_rate = imx8m_clk_composite_divider_determine_rate,
>  	.set_rate = imx8m_clk_composite_divider_set_rate,
>  };
>  
>  struct clk *imx8m_clk_composite_flags(const char *name,
>  					const char * const *parent_names,
> -- 
> 2.17.1
>
Leonard Crestez June 28, 2019, 8:56 a.m. UTC | #2 
On 28.06.2019 11:45, Abel Vesa wrote:
> On 19-06-28 10:39:50, Leonard Crestez wrote:

>> This allows consumers to use min_rate max_rate.
>>
>> @@ -45,10 +45,12 @@ static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw,
>>   				   divider->flags, PCG_DIV_WIDTH);
>>   }
>>   
>>   static int imx8m_clk_composite_compute_dividers(unsigned long rate,
>>   						unsigned long parent_rate,
>> +						unsigned long min_rate,
>> +						unsigned long max_rate,
> 
> You should pass on the req instead of min_rate and max_rate here.

Then I'd have to switch imx8m_clk_composite_divider_set_rate to allocate 
a dummy struct clk_rate_request on the stack. It's clearer if I just 
pass the minimum parameters required.

--
Regards,
Leonard
Abel Vesa July 2, 2019, 7:13 a.m. UTC | #3 
On 19-06-28 08:56:35, Leonard Crestez wrote:
> On 28.06.2019 11:45, Abel Vesa wrote:
> > On 19-06-28 10:39:50, Leonard Crestez wrote:
> 
> >> This allows consumers to use min_rate max_rate.
> >>
> >> @@ -45,10 +45,12 @@ static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw,
> >>   				   divider->flags, PCG_DIV_WIDTH);
> >>   }
> >>   
> >>   static int imx8m_clk_composite_compute_dividers(unsigned long rate,
> >>   						unsigned long parent_rate,
> >> +						unsigned long min_rate,
> >> +						unsigned long max_rate,
> > 
> > You should pass on the req instead of min_rate and max_rate here.
> 
> Then I'd have to switch imx8m_clk_composite_divider_set_rate to allocate 
> a dummy struct clk_rate_request on the stack. It's clearer if I just 
> pass the minimum parameters required.
> 

That is correct. Nevermind my earlier comment then.

> --
> Regards,
> Leonard
>
diff mbox series

Patch

diff --git a/drivers/clk/imx/clk-composite-8m.c b/drivers/clk/imx/clk-composite-8m.c
index 388bdb94f841..1be82ec08ecd 100644
--- a/drivers/clk/imx/clk-composite-8m.c
+++ b/drivers/clk/imx/clk-composite-8m.c
@@ -45,10 +45,12 @@  static unsigned long imx8m_clk_composite_divider_recalc_rate(struct clk_hw *hw,
 				   divider->flags, PCG_DIV_WIDTH);
 }
 
 static int imx8m_clk_composite_compute_dividers(unsigned long rate,
 						unsigned long parent_rate,
+						unsigned long min_rate,
+						unsigned long max_rate,
 						int *prediv, int *postdiv)
 {
 	int div1, div2;
 	int error = INT_MAX;
 	int ret = -EINVAL;
@@ -56,11 +58,17 @@  static int imx8m_clk_composite_compute_dividers(unsigned long rate,
 	*prediv = 1;
 	*postdiv = 1;
 
 	for (div1 = 1; div1 <= PCG_PREDIV_MAX; div1++) {
 		for (div2 = 1; div2 <= PCG_DIV_MAX; div2++) {
-			int new_error = ((parent_rate / div1) / div2) - rate;
+			unsigned long new_rate;
+			int new_error;
+
+			new_rate = ((parent_rate / div1) / div2);
+			if (new_rate < min_rate || new_rate > max_rate)
+				continue;
+			new_error = new_rate - rate;
 
 			if (abs(new_error) < abs(error)) {
 				*prediv = div1;
 				*postdiv = div2;
 				error = new_error;
@@ -69,38 +77,40 @@  static int imx8m_clk_composite_compute_dividers(unsigned long rate,
 		}
 	}
 	return ret;
 }
 
-static long imx8m_clk_composite_divider_round_rate(struct clk_hw *hw,
-						unsigned long rate,
-						unsigned long *prate)
+static int imx8m_clk_composite_divider_determine_rate(struct clk_hw *hw,
+						       struct clk_rate_request *req)
 {
 	int prediv_value;
 	int div_value;
 
-	imx8m_clk_composite_compute_dividers(rate, *prate,
-						&prediv_value, &div_value);
-	rate = DIV_ROUND_UP(*prate, prediv_value);
+	imx8m_clk_composite_compute_dividers(req->rate, req->best_parent_rate,
+					     req->min_rate, req->max_rate,
+					     &prediv_value, &div_value);
 
-	return DIV_ROUND_UP(rate, div_value);
+	req->rate = DIV_ROUND_UP(req->best_parent_rate, prediv_value);
+	req->rate = DIV_ROUND_UP(req->rate, div_value);
 
+	return 0;
 }
 
 static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw,
-					unsigned long rate,
-					unsigned long parent_rate)
+						unsigned long rate,
+						unsigned long parent_rate)
 {
 	struct clk_divider *divider = to_clk_divider(hw);
 	unsigned long flags = 0;
 	int prediv_value;
 	int div_value;
 	int ret;
 	u32 val;
 
 	ret = imx8m_clk_composite_compute_dividers(rate, parent_rate,
-						&prediv_value, &div_value);
+						   0, ULONG_MAX,
+						   &prediv_value, &div_value);
 	if (ret)
 		return -EINVAL;
 
 	spin_lock_irqsave(divider->lock, flags);
 
@@ -117,11 +127,11 @@  static int imx8m_clk_composite_divider_set_rate(struct clk_hw *hw,
 	return ret;
 }
 
 static const struct clk_ops imx8m_clk_composite_divider_ops = {
 	.recalc_rate = imx8m_clk_composite_divider_recalc_rate,
-	.round_rate = imx8m_clk_composite_divider_round_rate,
+	.determine_rate = imx8m_clk_composite_divider_determine_rate,
 	.set_rate = imx8m_clk_composite_divider_set_rate,
 };
 
 struct clk *imx8m_clk_composite_flags(const char *name,
 					const char * const *parent_names,