diff mbox series

[v4,08/11] clk: sunxi-ng: nkm: Support finding closest rate

Message ID 20230717-pll-mipi_set_rate_parent-v4-8-04acf1d39765@oltmanns.dev
State New
Headers
Series clk: sunxi-ng: Consider alternative parent rates when determining NKM clock rate |

Commit Message

Frank Oltmanns July 17, 2023, 1:34 p.m. UTC 
  When finding the best rate for a NKM clock, consider rates that are
higher than the requested rate, if the CCU_FEATURE_CLOSEST_RATE flag is
set by using the helper function ccu_is_better_rate().

Accommodate ccu_mux_helper_determine_rate to this change.

Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
---
 drivers/clk/sunxi-ng/ccu_mux.c |  2 +-
 drivers/clk/sunxi-ng/ccu_nkm.c | 18 ++++++++----------
 2 files changed, 9 insertions(+), 11 deletions(-)

Comments

Maxime Ripard July 17, 2023, 2:14 p.m. UTC | #1 
On Mon, Jul 17, 2023 at 03:34:32PM +0200, Frank Oltmanns wrote:
> When finding the best rate for a NKM clock, consider rates that are
> higher than the requested rate, if the CCU_FEATURE_CLOSEST_RATE flag is
> set by using the helper function ccu_is_better_rate().
> 
> Accommodate ccu_mux_helper_determine_rate to this change.
> 
> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
> ---
>  drivers/clk/sunxi-ng/ccu_mux.c |  2 +-
>  drivers/clk/sunxi-ng/ccu_nkm.c | 18 ++++++++----------
>  2 files changed, 9 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
> index 1d557e323169..3ca695439620 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.c
> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
> @@ -139,7 +139,7 @@ int ccu_mux_helper_determine_rate(struct ccu_common *common,
>  			goto out;
>  		}
>  
> -		if ((req->rate - tmp_rate) < (req->rate - best_rate)) {
> +		if (ccu_is_better_rate(common, req->rate, tmp_rate, best_rate)) {
>  			best_rate = tmp_rate;
>  			best_parent_rate = parent_rate;
>  			best_parent = parent;
> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> index 793160bc2d47..5439b9351cd7 100644
> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> @@ -39,6 +39,7 @@ static unsigned long ccu_nkm_optimal_parent_rate(unsigned long rate, unsigned lo
>  }
>  
>  static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struct _ccu_nkm *nkm,
> +						       struct ccu_common *common,
>  						       unsigned long *parent, unsigned long rate)
>  {
>  	unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent = *parent;
> @@ -54,10 +55,8 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
>  				tmp_parent = clk_hw_round_rate(phw, tmp_parent);
>  
>  				tmp_rate = tmp_parent * _n * _k / _m;
> -				if (tmp_rate > rate)
> -					continue;
>  
> -				if ((rate - tmp_rate) < (rate - best_rate)) {
> +				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
>  					best_rate = tmp_rate;
>  					best_parent_rate = tmp_parent;
>  					best_n = _n;
> @@ -78,7 +77,7 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
>  }
>  
>  static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
> -				       struct _ccu_nkm *nkm)
> +				       struct _ccu_nkm *nkm, struct ccu_common *common)

Same comment than on patch 7, common should be first in those two functions.

Once fixed,
Acked-by: Maxime Ripard <mripard@kernel.org>

Maxime
Frank Oltmanns July 23, 2023, 7:25 a.m. UTC | #2 
Hi Maxime,

On 2023-07-17 at 16:14:58 +0200, Maxime Ripard <mripard@kernel.org> wrote:
> [[PGP Signed Part:Undecided]]
> On Mon, Jul 17, 2023 at 03:34:32PM +0200, Frank Oltmanns wrote:
>> When finding the best rate for a NKM clock, consider rates that are
>> higher than the requested rate, if the CCU_FEATURE_CLOSEST_RATE flag is
>> set by using the helper function ccu_is_better_rate().
>>
>> Accommodate ccu_mux_helper_determine_rate to this change.
>>
>> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
>> ---
>>  drivers/clk/sunxi-ng/ccu_mux.c |  2 +-
>>  drivers/clk/sunxi-ng/ccu_nkm.c | 18 ++++++++----------
>>  2 files changed, 9 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
>> index 1d557e323169..3ca695439620 100644
>> --- a/drivers/clk/sunxi-ng/ccu_mux.c
>> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
>> @@ -139,7 +139,7 @@ int ccu_mux_helper_determine_rate(struct ccu_common *common,
>>  			goto out;
>>  		}
>>
>> -		if ((req->rate - tmp_rate) < (req->rate - best_rate)) {
>> +		if (ccu_is_better_rate(common, req->rate, tmp_rate, best_rate)) {
>>  			best_rate = tmp_rate;
>>  			best_parent_rate = parent_rate;
>>  			best_parent = parent;
>> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
>> index 793160bc2d47..5439b9351cd7 100644
>> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
>> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
>> @@ -39,6 +39,7 @@ static unsigned long ccu_nkm_optimal_parent_rate(unsigned long rate, unsigned lo
>>  }
>>
>>  static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struct _ccu_nkm *nkm,
>> +						       struct ccu_common *common,
>>  						       unsigned long *parent, unsigned long rate)
>>  {
>>  	unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent = *parent;
>> @@ -54,10 +55,8 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
>>  				tmp_parent = clk_hw_round_rate(phw, tmp_parent);
>>
>>  				tmp_rate = tmp_parent * _n * _k / _m;
>> -				if (tmp_rate > rate)
>> -					continue;
>>
>> -				if ((rate - tmp_rate) < (rate - best_rate)) {
>> +				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
>>  					best_rate = tmp_rate;
>>  					best_parent_rate = tmp_parent;
>>  					best_n = _n;
>> @@ -78,7 +77,7 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
>>  }
>>
>>  static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
>> -				       struct _ccu_nkm *nkm)
>> +				       struct _ccu_nkm *nkm, struct ccu_common *common)
>
> Same comment than on patch 7, common should be first in those two functions.
>

Ok, I wasn't sure what your expectation is for existing functions. For
ccu_find_best_with_parent_adj the order is:
  1. *phw
  2. *nkm
  3. *common
  4. *parent
  5. rate

We don't have the parent hw in ccu_nkm_find_best. The order prior to
this patch is:
  1. parent
  2. rate
  3. *nkm

We need to add *common to that, so I could add it to the beginning as
per your suggestion:
  1. *common
  2. parent
  3. rate
  4. *nkm

I could also pull *nkm to the beginning (similar to the parent_adj
version):
  4. *nkm
  1. *common
  2. parent
  3. rate

Thanks for your feedback,
  Frank

>
> Once fixed,
> Acked-by: Maxime Ripard <mripard@kernel.org>
>
> Maxime
>
> [[End of PGP Signed Part]]
Maxime Ripard July 24, 2023, 1:19 p.m. UTC | #3 
On Sun, Jul 23, 2023 at 09:25:10AM +0200, Frank Oltmanns wrote:
> On 2023-07-17 at 16:14:58 +0200, Maxime Ripard <mripard@kernel.org> wrote:
> > [[PGP Signed Part:Undecided]]
> > On Mon, Jul 17, 2023 at 03:34:32PM +0200, Frank Oltmanns wrote:
> >> When finding the best rate for a NKM clock, consider rates that are
> >> higher than the requested rate, if the CCU_FEATURE_CLOSEST_RATE flag is
> >> set by using the helper function ccu_is_better_rate().
> >>
> >> Accommodate ccu_mux_helper_determine_rate to this change.
> >>
> >> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
> >> ---
> >>  drivers/clk/sunxi-ng/ccu_mux.c |  2 +-
> >>  drivers/clk/sunxi-ng/ccu_nkm.c | 18 ++++++++----------
> >>  2 files changed, 9 insertions(+), 11 deletions(-)
> >>
> >> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
> >> index 1d557e323169..3ca695439620 100644
> >> --- a/drivers/clk/sunxi-ng/ccu_mux.c
> >> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
> >> @@ -139,7 +139,7 @@ int ccu_mux_helper_determine_rate(struct ccu_common *common,
> >>  			goto out;
> >>  		}
> >>
> >> -		if ((req->rate - tmp_rate) < (req->rate - best_rate)) {
> >> +		if (ccu_is_better_rate(common, req->rate, tmp_rate, best_rate)) {
> >>  			best_rate = tmp_rate;
> >>  			best_parent_rate = parent_rate;
> >>  			best_parent = parent;
> >> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> >> index 793160bc2d47..5439b9351cd7 100644
> >> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
> >> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> >> @@ -39,6 +39,7 @@ static unsigned long ccu_nkm_optimal_parent_rate(unsigned long rate, unsigned lo
> >>  }
> >>
> >>  static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struct _ccu_nkm *nkm,
> >> +						       struct ccu_common *common,
> >>  						       unsigned long *parent, unsigned long rate)
> >>  {
> >>  	unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent = *parent;
> >> @@ -54,10 +55,8 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
> >>  				tmp_parent = clk_hw_round_rate(phw, tmp_parent);
> >>
> >>  				tmp_rate = tmp_parent * _n * _k / _m;
> >> -				if (tmp_rate > rate)
> >> -					continue;
> >>
> >> -				if ((rate - tmp_rate) < (rate - best_rate)) {
> >> +				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
> >>  					best_rate = tmp_rate;
> >>  					best_parent_rate = tmp_parent;
> >>  					best_n = _n;
> >> @@ -78,7 +77,7 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
> >>  }
> >>
> >>  static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
> >> -				       struct _ccu_nkm *nkm)
> >> +				       struct _ccu_nkm *nkm, struct ccu_common *common)
> >
> > Same comment than on patch 7, common should be first in those two functions.
> >
> 
> Ok, I wasn't sure what your expectation is for existing functions. For
> ccu_find_best_with_parent_adj the order is:
>   1. *phw
>   2. *nkm
>   3. *common
>   4. *parent
>   5. rate

Arguments are generally ordered by putting first what the function will
act upon, and then from generic to specific, and output last.

Which I guess would make the ideal one something like:
*common
*parent_hw
*parent
rate
nkm

> We don't have the parent hw in ccu_nkm_find_best. The order prior to
> this patch is:
>   1. parent
>   2. rate
>   3. *nkm
> 
> We need to add *common to that, so I could add it to the beginning as
> per your suggestion:
>   1. *common
>   2. parent
>   3. rate
>   4. *nkm

Those two make sense to me

> I could also pull *nkm to the beginning (similar to the parent_adj
> version):
>   4. *nkm
>   1. *common
>   2. parent
>   3. rate

nkm is an output, it needs to be last.

Maxime
diff mbox series

Patch

diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
index 1d557e323169..3ca695439620 100644
--- a/drivers/clk/sunxi-ng/ccu_mux.c
+++ b/drivers/clk/sunxi-ng/ccu_mux.c
@@ -139,7 +139,7 @@  int ccu_mux_helper_determine_rate(struct ccu_common *common,
 			goto out;
 		}
 
-		if ((req->rate - tmp_rate) < (req->rate - best_rate)) {
+		if (ccu_is_better_rate(common, req->rate, tmp_rate, best_rate)) {
 			best_rate = tmp_rate;
 			best_parent_rate = parent_rate;
 			best_parent = parent;
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 793160bc2d47..5439b9351cd7 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -39,6 +39,7 @@  static unsigned long ccu_nkm_optimal_parent_rate(unsigned long rate, unsigned lo
 }
 
 static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struct _ccu_nkm *nkm,
+						       struct ccu_common *common,
 						       unsigned long *parent, unsigned long rate)
 {
 	unsigned long best_rate = 0, best_parent_rate = *parent, tmp_parent = *parent;
@@ -54,10 +55,8 @@  static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
 				tmp_parent = clk_hw_round_rate(phw, tmp_parent);
 
 				tmp_rate = tmp_parent * _n * _k / _m;
-				if (tmp_rate > rate)
-					continue;
 
-				if ((rate - tmp_rate) < (rate - best_rate)) {
+				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
 					best_rate = tmp_rate;
 					best_parent_rate = tmp_parent;
 					best_n = _n;
@@ -78,7 +77,7 @@  static unsigned long ccu_nkm_find_best_with_parent_adj(struct clk_hw *phw, struc
 }
 
 static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
-				       struct _ccu_nkm *nkm)
+				       struct _ccu_nkm *nkm, struct ccu_common *common)
 {
 	unsigned long best_rate = 0;
 	unsigned long best_n = 0, best_k = 0, best_m = 0;
@@ -91,9 +90,7 @@  static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
 
 				tmp_rate = parent * _n * _k / _m;
 
-				if (tmp_rate > rate)
-					continue;
-				if ((rate - tmp_rate) < (rate - best_rate)) {
+				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate)) {
 					best_rate = tmp_rate;
 					best_n = _n;
 					best_k = _k;
@@ -186,9 +183,10 @@  static unsigned long ccu_nkm_round_rate(struct ccu_mux_internal *mux,
 		rate *= nkm->fixed_post_div;
 
 	if (!clk_hw_can_set_rate_parent(&nkm->common.hw))
-		rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm);
+		rate = ccu_nkm_find_best(*parent_rate, rate, &_nkm, &nkm->common);
 	else
-		rate = ccu_nkm_find_best_with_parent_adj(parent_hw, &_nkm, parent_rate, rate);
+		rate = ccu_nkm_find_best_with_parent_adj(parent_hw, &_nkm, &nkm->common,
+							 parent_rate, rate);
 
 	if (nkm->common.features & CCU_FEATURE_FIXED_POSTDIV)
 		rate /= nkm->fixed_post_div;
@@ -223,7 +221,7 @@  static int ccu_nkm_set_rate(struct clk_hw *hw, unsigned long rate,
 	_nkm.min_m = 1;
 	_nkm.max_m = nkm->m.max ?: 1 << nkm->m.width;
 
-	ccu_nkm_find_best(parent_rate, rate, &_nkm);
+	ccu_nkm_find_best(parent_rate, rate, &_nkm, &nkm->common);
 
 	spin_lock_irqsave(nkm->common.lock, flags);