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[PATCH v2 1/6] clk: sunxi-ng: nkm: Support constraints on m/n ratio and parent rate

Frank Oltmanns posted 6 patches 2 years ago
There is a newer version of this series
[PATCH v2 1/6] clk: sunxi-ng: nkm: Support constraints on m/n ratio and parent rate
Posted by Frank Oltmanns 2 years ago 
The Allwinner A64 manual lists the following constraints for the
PLL-MIPI clock:
 - M/N <= 3
 - (PLL_VIDEO0)/M >= 24MHz

The PLL-MIPI clock is implemented as ccu_nkm. Therefore, add support for
these constraints.

Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
---
 drivers/clk/sunxi-ng/ccu_nkm.c | 21 +++++++++++++++++++++
 drivers/clk/sunxi-ng/ccu_nkm.h |  2 ++
 2 files changed, 23 insertions(+)

diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
index 853f84398e2b..1168d894d636 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.c
+++ b/drivers/clk/sunxi-ng/ccu_nkm.c
@@ -16,6 +16,20 @@ struct _ccu_nkm {
 	unsigned long	m, min_m, max_m;
 };
 
+static bool ccu_nkm_is_valid_rate(struct ccu_common *common, unsigned long parent,
+				  unsigned long n, unsigned long m)
+{
+	struct ccu_nkm *nkm = container_of(common, struct ccu_nkm, common);
+
+	if (nkm->max_m_n_ratio && (m > nkm->max_m_n_ratio * n))
+		return false;
+
+	if (nkm->min_parent_m_ratio && (parent < nkm->min_parent_m_ratio * m))
+		return false;
+
+	return true;
+}
+
 static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
 						       struct clk_hw *parent_hw,
 						       unsigned long *parent, unsigned long rate,
@@ -31,6 +45,10 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common
 				unsigned long tmp_rate, tmp_parent;
 
 				tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
+
+				if (!ccu_nkm_is_valid_rate(common, tmp_parent, _n, _m))
+					continue;
+
 				tmp_rate = tmp_parent * _n * _k / _m;
 
 				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
@@ -64,6 +82,9 @@ static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
 	for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
 		for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
 			for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
+				if (!ccu_nkm_is_valid_rate(common, parent, _n, _m))
+					continue;
+
 				unsigned long tmp_rate;
 
 				tmp_rate = parent * _n * _k / _m;
diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
index 6601defb3f38..c409212ee40e 100644
--- a/drivers/clk/sunxi-ng/ccu_nkm.h
+++ b/drivers/clk/sunxi-ng/ccu_nkm.h
@@ -27,6 +27,8 @@ struct ccu_nkm {
 	struct ccu_mux_internal	mux;
 
 	unsigned int		fixed_post_div;
+	unsigned long		max_m_n_ratio;
+	unsigned long		min_parent_m_ratio;
 
 	struct ccu_common	common;
 };

-- 
2.43.0
Re: [PATCH v2 1/6] clk: sunxi-ng: nkm: Support constraints on m/n ratio and parent rate
Posted by Jernej Škrabec 2 years ago 
Dne ponedeljek, 05. februar 2024 ob 16:22:24 CET je Frank Oltmanns napisal(a):
> The Allwinner A64 manual lists the following constraints for the
> PLL-MIPI clock:
>  - M/N <= 3
>  - (PLL_VIDEO0)/M >= 24MHz
> 
> The PLL-MIPI clock is implemented as ccu_nkm. Therefore, add support for
> these constraints.
> 
> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>

Haven't we discussed that this patch is unnecessary because same effect can
be reached by limiting minimum frequency?

Best regards,
Jernej

> ---
>  drivers/clk/sunxi-ng/ccu_nkm.c | 21 +++++++++++++++++++++
>  drivers/clk/sunxi-ng/ccu_nkm.h |  2 ++
>  2 files changed, 23 insertions(+)
> 
> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> index 853f84398e2b..1168d894d636 100644
> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> @@ -16,6 +16,20 @@ struct _ccu_nkm {
>  	unsigned long	m, min_m, max_m;
>  };
>  
> +static bool ccu_nkm_is_valid_rate(struct ccu_common *common, unsigned long parent,
> +				  unsigned long n, unsigned long m)
> +{
> +	struct ccu_nkm *nkm = container_of(common, struct ccu_nkm, common);
> +
> +	if (nkm->max_m_n_ratio && (m > nkm->max_m_n_ratio * n))
> +		return false;
> +
> +	if (nkm->min_parent_m_ratio && (parent < nkm->min_parent_m_ratio * m))
> +		return false;
> +
> +	return true;
> +}
> +
>  static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
>  						       struct clk_hw *parent_hw,
>  						       unsigned long *parent, unsigned long rate,
> @@ -31,6 +45,10 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common
>  				unsigned long tmp_rate, tmp_parent;
>  
>  				tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
> +
> +				if (!ccu_nkm_is_valid_rate(common, tmp_parent, _n, _m))
> +					continue;
> +
>  				tmp_rate = tmp_parent * _n * _k / _m;
>  
>  				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
> @@ -64,6 +82,9 @@ static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
>  	for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
>  		for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
>  			for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
> +				if (!ccu_nkm_is_valid_rate(common, parent, _n, _m))
> +					continue;
> +
>  				unsigned long tmp_rate;
>  
>  				tmp_rate = parent * _n * _k / _m;
> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
> index 6601defb3f38..c409212ee40e 100644
> --- a/drivers/clk/sunxi-ng/ccu_nkm.h
> +++ b/drivers/clk/sunxi-ng/ccu_nkm.h
> @@ -27,6 +27,8 @@ struct ccu_nkm {
>  	struct ccu_mux_internal	mux;
>  
>  	unsigned int		fixed_post_div;
> +	unsigned long		max_m_n_ratio;
> +	unsigned long		min_parent_m_ratio;
>  
>  	struct ccu_common	common;
>  };
> 
>
Re: [PATCH v2 1/6] clk: sunxi-ng: nkm: Support constraints on m/n ratio and parent rate
Posted by Frank Oltmanns 2 years ago 
Hi Jernej,

On 2024-02-05 at 18:45:27 +0100, Jernej Škrabec <jernej.skrabec@gmail.com> wrote:
> Dne ponedeljek, 05. februar 2024 ob 16:22:24 CET je Frank Oltmanns napisal(a):
>> The Allwinner A64 manual lists the following constraints for the
>> PLL-MIPI clock:
>>  - M/N <= 3
>>  - (PLL_VIDEO0)/M >= 24MHz
>>
>> The PLL-MIPI clock is implemented as ccu_nkm. Therefore, add support for
>> these constraints.
>>
>> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
>
> Haven't we discussed that this patch is unnecessary because same effect can
> be reached by limiting minimum frequency?

The patch for ccu_nm was unnecessary:
https://lore.kernel.org/all/87jzoug2jz.fsf@oltmanns.dev/

Unfortunately, we still need this one.

Best regards,
  Frank

>
> Best regards,
> Jernej
>
>> ---
>>  drivers/clk/sunxi-ng/ccu_nkm.c | 21 +++++++++++++++++++++
>>  drivers/clk/sunxi-ng/ccu_nkm.h |  2 ++
>>  2 files changed, 23 insertions(+)
>>
>> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
>> index 853f84398e2b..1168d894d636 100644
>> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
>> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
>> @@ -16,6 +16,20 @@ struct _ccu_nkm {
>>  	unsigned long	m, min_m, max_m;
>>  };
>>
>> +static bool ccu_nkm_is_valid_rate(struct ccu_common *common, unsigned long parent,
>> +				  unsigned long n, unsigned long m)
>> +{
>> +	struct ccu_nkm *nkm = container_of(common, struct ccu_nkm, common);
>> +
>> +	if (nkm->max_m_n_ratio && (m > nkm->max_m_n_ratio * n))
>> +		return false;
>> +
>> +	if (nkm->min_parent_m_ratio && (parent < nkm->min_parent_m_ratio * m))
>> +		return false;
>> +
>> +	return true;
>> +}
>> +
>>  static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
>>  						       struct clk_hw *parent_hw,
>>  						       unsigned long *parent, unsigned long rate,
>> @@ -31,6 +45,10 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common
>>  				unsigned long tmp_rate, tmp_parent;
>>
>>  				tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
>> +
>> +				if (!ccu_nkm_is_valid_rate(common, tmp_parent, _n, _m))
>> +					continue;
>> +
>>  				tmp_rate = tmp_parent * _n * _k / _m;
>>
>>  				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
>> @@ -64,6 +82,9 @@ static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
>>  	for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
>>  		for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
>>  			for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
>> +				if (!ccu_nkm_is_valid_rate(common, parent, _n, _m))
>> +					continue;
>> +
>>  				unsigned long tmp_rate;
>>
>>  				tmp_rate = parent * _n * _k / _m;
>> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
>> index 6601defb3f38..c409212ee40e 100644
>> --- a/drivers/clk/sunxi-ng/ccu_nkm.h
>> +++ b/drivers/clk/sunxi-ng/ccu_nkm.h
>> @@ -27,6 +27,8 @@ struct ccu_nkm {
>>  	struct ccu_mux_internal	mux;
>>
>>  	unsigned int		fixed_post_div;
>> +	unsigned long		max_m_n_ratio;
>> +	unsigned long		min_parent_m_ratio;
>>
>>  	struct ccu_common	common;
>>  };
>>
>>
Re: [PATCH v2 1/6] clk: sunxi-ng: nkm: Support constraints on m/n ratio and parent rate
Posted by Jernej Škrabec 2 years ago 
Dne ponedeljek, 05. februar 2024 ob 18:50:27 CET je Frank Oltmanns napisal(a):
> Hi Jernej,
> 
> On 2024-02-05 at 18:45:27 +0100, Jernej Škrabec <jernej.skrabec@gmail.com> wrote:
> > Dne ponedeljek, 05. februar 2024 ob 16:22:24 CET je Frank Oltmanns napisal(a):
> >> The Allwinner A64 manual lists the following constraints for the
> >> PLL-MIPI clock:
> >>  - M/N <= 3
> >>  - (PLL_VIDEO0)/M >= 24MHz
> >>
> >> The PLL-MIPI clock is implemented as ccu_nkm. Therefore, add support for
> >> these constraints.
> >>
> >> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
> >
> > Haven't we discussed that this patch is unnecessary because same effect can
> > be reached by limiting minimum frequency?
> 
> The patch for ccu_nm was unnecessary:
> https://lore.kernel.org/all/87jzoug2jz.fsf@oltmanns.dev/
> 
> Unfortunately, we still need this one.

Ok, then:
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

> 
> Best regards,
>   Frank
> 
> >
> > Best regards,
> > Jernej
> >
> >> ---
> >>  drivers/clk/sunxi-ng/ccu_nkm.c | 21 +++++++++++++++++++++
> >>  drivers/clk/sunxi-ng/ccu_nkm.h |  2 ++
> >>  2 files changed, 23 insertions(+)
> >>
> >> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.c b/drivers/clk/sunxi-ng/ccu_nkm.c
> >> index 853f84398e2b..1168d894d636 100644
> >> --- a/drivers/clk/sunxi-ng/ccu_nkm.c
> >> +++ b/drivers/clk/sunxi-ng/ccu_nkm.c
> >> @@ -16,6 +16,20 @@ struct _ccu_nkm {
> >>  	unsigned long	m, min_m, max_m;
> >>  };
> >>
> >> +static bool ccu_nkm_is_valid_rate(struct ccu_common *common, unsigned long parent,
> >> +				  unsigned long n, unsigned long m)
> >> +{
> >> +	struct ccu_nkm *nkm = container_of(common, struct ccu_nkm, common);
> >> +
> >> +	if (nkm->max_m_n_ratio && (m > nkm->max_m_n_ratio * n))
> >> +		return false;
> >> +
> >> +	if (nkm->min_parent_m_ratio && (parent < nkm->min_parent_m_ratio * m))
> >> +		return false;
> >> +
> >> +	return true;
> >> +}
> >> +
> >>  static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common,
> >>  						       struct clk_hw *parent_hw,
> >>  						       unsigned long *parent, unsigned long rate,
> >> @@ -31,6 +45,10 @@ static unsigned long ccu_nkm_find_best_with_parent_adj(struct ccu_common *common
> >>  				unsigned long tmp_rate, tmp_parent;
> >>
> >>  				tmp_parent = clk_hw_round_rate(parent_hw, rate * _m / (_n * _k));
> >> +
> >> +				if (!ccu_nkm_is_valid_rate(common, tmp_parent, _n, _m))
> >> +					continue;
> >> +
> >>  				tmp_rate = tmp_parent * _n * _k / _m;
> >>
> >>  				if (ccu_is_better_rate(common, rate, tmp_rate, best_rate) ||
> >> @@ -64,6 +82,9 @@ static unsigned long ccu_nkm_find_best(unsigned long parent, unsigned long rate,
> >>  	for (_k = nkm->min_k; _k <= nkm->max_k; _k++) {
> >>  		for (_n = nkm->min_n; _n <= nkm->max_n; _n++) {
> >>  			for (_m = nkm->min_m; _m <= nkm->max_m; _m++) {
> >> +				if (!ccu_nkm_is_valid_rate(common, parent, _n, _m))
> >> +					continue;
> >> +
> >>  				unsigned long tmp_rate;
> >>
> >>  				tmp_rate = parent * _n * _k / _m;
> >> diff --git a/drivers/clk/sunxi-ng/ccu_nkm.h b/drivers/clk/sunxi-ng/ccu_nkm.h
> >> index 6601defb3f38..c409212ee40e 100644
> >> --- a/drivers/clk/sunxi-ng/ccu_nkm.h
> >> +++ b/drivers/clk/sunxi-ng/ccu_nkm.h
> >> @@ -27,6 +27,8 @@ struct ccu_nkm {
> >>  	struct ccu_mux_internal	mux;
> >>
> >>  	unsigned int		fixed_post_div;
> >> +	unsigned long		max_m_n_ratio;
> >> +	unsigned long		min_parent_m_ratio;
> >>
> >>  	struct ccu_common	common;
> >>  };
> >>
> >>
>

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