[v3,6/8] clk: sunxi-ng: mux: Support finding closest rate

  When finding the best rate for a mux clock, consider rates that are
higher than the requested rate by introducing a new clk_ops structure
that uses the existing __clk_mux_determine_rate_closest function.
Furthermore introduce an initialization macro that uses this new
structure.

Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
---
 drivers/clk/sunxi-ng/ccu_mux.c | 13 +++++++++++++
 drivers/clk/sunxi-ng/ccu_mux.h | 17 +++++++++++++++++
 2 files changed, 30 insertions(+)
  

On Sun, Jul 02, 2023 at 07:55:25PM +0200, Frank Oltmanns wrote:
> When finding the best rate for a mux clock, consider rates that are
> higher than the requested rate by introducing a new clk_ops structure
> that uses the existing __clk_mux_determine_rate_closest function.
> Furthermore introduce an initialization macro that uses this new
> structure.
> 
> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
> ---
>  drivers/clk/sunxi-ng/ccu_mux.c | 13 +++++++++++++
>  drivers/clk/sunxi-ng/ccu_mux.h | 17 +++++++++++++++++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
> index 8594d6a4addd..49a592bdeacf 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.c
> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
> @@ -264,6 +264,19 @@ static unsigned long ccu_mux_recalc_rate(struct clk_hw *hw,
>  					   parent_rate);
>  }
>  
> +const struct clk_ops ccu_mux_closest_ops = {
> +	.disable	= ccu_mux_disable,
> +	.enable		= ccu_mux_enable,
> +	.is_enabled	= ccu_mux_is_enabled,
> +
> +	.get_parent	= ccu_mux_get_parent,
> +	.set_parent	= ccu_mux_set_parent,
> +
> +	.determine_rate	= __clk_mux_determine_rate_closest,
> +	.recalc_rate	= ccu_mux_recalc_rate,
> +};
> +EXPORT_SYMBOL_NS_GPL(ccu_mux_closest_ops, SUNXI_CCU);
> +

This is also a bit inconsistent with the other clocks: most (all?) of
them will simply handle this through a flag, but this one requires a new
set of clk_ops as well?

I think we should create our own wrapper here around
__clk_mux_determine_rate and either call
__clk_mux_determine_rate_closest or __clk_mux_determine_rate depending
on the state of the flags, or call __clk_mux_determine_rate_flags with
the proper flags set for our clock.

The former is probably slightly simpler.

>  const struct clk_ops ccu_mux_ops = {
>  	.disable	= ccu_mux_disable,
>  	.enable		= ccu_mux_enable,
> diff --git a/drivers/clk/sunxi-ng/ccu_mux.h b/drivers/clk/sunxi-ng/ccu_mux.h
> index 2c1811a445b0..c4ee14e43719 100644
> --- a/drivers/clk/sunxi-ng/ccu_mux.h
> +++ b/drivers/clk/sunxi-ng/ccu_mux.h
> @@ -46,6 +46,22 @@ struct ccu_mux {
>  	struct ccu_common	common;
>  };
>  
> +#define SUNXI_CCU_MUX_TABLE_WITH_GATE_CLOSEST(_struct, _name, _parents, _table,	\
> +				     _reg, _shift, _width, _gate,	\
> +				     _flags)				\
> +	struct ccu_mux _struct = {					\
> +		.enable	= _gate,					\
> +		.mux	= _SUNXI_CCU_MUX_TABLE(_shift, _width, _table),	\
> +		.common	= {						\
> +			.reg		= _reg,				\
> +			.hw.init	= CLK_HW_INIT_PARENTS(_name,	\
> +							      _parents, \
> +							      &ccu_mux_closest_ops, \
> +							      _flags),	\
> +			.features	= CCU_FEATURE_CLOSEST_RATE,	\
> +		}							\
> +	}
> +

I'm fine with that one, but like we discussed on the NM (I think?) patch
already, this creates some clocks and macros that will use the feature
as a flag, and some will encode it into their name.

Given that we need it here too, I'm really inclined to prefer what you
did there, and thus create a new macro for pll-video0 instead of
modifying the existing one.

Maxime
  

On 2023-07-03 at 09:38:48 +0200, Maxime Ripard <maxime@cerno.tech> wrote:
> [[PGP Signed Part:Undecided]]
> On Sun, Jul 02, 2023 at 07:55:25PM +0200, Frank Oltmanns wrote:
>> When finding the best rate for a mux clock, consider rates that are
>> higher than the requested rate by introducing a new clk_ops structure
>> that uses the existing __clk_mux_determine_rate_closest function.
>> Furthermore introduce an initialization macro that uses this new
>> structure.
>>
>> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
>> ---
>>  drivers/clk/sunxi-ng/ccu_mux.c | 13 +++++++++++++
>>  drivers/clk/sunxi-ng/ccu_mux.h | 17 +++++++++++++++++
>>  2 files changed, 30 insertions(+)
>>
>> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
>> index 8594d6a4addd..49a592bdeacf 100644
>> --- a/drivers/clk/sunxi-ng/ccu_mux.c
>> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
>> @@ -264,6 +264,19 @@ static unsigned long ccu_mux_recalc_rate(struct clk_hw *hw,
>>  					   parent_rate);
>>  }
>>
>> +const struct clk_ops ccu_mux_closest_ops = {
>> +	.disable	= ccu_mux_disable,
>> +	.enable		= ccu_mux_enable,
>> +	.is_enabled	= ccu_mux_is_enabled,
>> +
>> +	.get_parent	= ccu_mux_get_parent,
>> +	.set_parent	= ccu_mux_set_parent,
>> +
>> +	.determine_rate	= __clk_mux_determine_rate_closest,
>> +	.recalc_rate	= ccu_mux_recalc_rate,
>> +};
>> +EXPORT_SYMBOL_NS_GPL(ccu_mux_closest_ops, SUNXI_CCU);
>> +
>
> This is also a bit inconsistent with the other clocks: most (all?) of
> them will simply handle this through a flag, but this one requires a new
> set of clk_ops as well?
>
> I think we should create our own wrapper here around
> __clk_mux_determine_rate and either call
> __clk_mux_determine_rate_closest or __clk_mux_determine_rate depending
> on the state of the flags, or call __clk_mux_determine_rate_flags with
> the proper flags set for our clock.
>
> The former is probably slightly simpler.

Ok, I will address that in v4.

>
>>  const struct clk_ops ccu_mux_ops = {
>>  	.disable	= ccu_mux_disable,
>>  	.enable		= ccu_mux_enable,
>> diff --git a/drivers/clk/sunxi-ng/ccu_mux.h b/drivers/clk/sunxi-ng/ccu_mux.h
>> index 2c1811a445b0..c4ee14e43719 100644
>> --- a/drivers/clk/sunxi-ng/ccu_mux.h
>> +++ b/drivers/clk/sunxi-ng/ccu_mux.h
>> @@ -46,6 +46,22 @@ struct ccu_mux {
>>  	struct ccu_common	common;
>>  };
>>
>> +#define SUNXI_CCU_MUX_TABLE_WITH_GATE_CLOSEST(_struct, _name, _parents, _table,	\
>> +				     _reg, _shift, _width, _gate,	\
>> +				     _flags)				\
>> +	struct ccu_mux _struct = {					\
>> +		.enable	= _gate,					\
>> +		.mux	= _SUNXI_CCU_MUX_TABLE(_shift, _width, _table),	\
>> +		.common	= {						\
>> +			.reg		= _reg,				\
>> +			.hw.init	= CLK_HW_INIT_PARENTS(_name,	\
>> +							      _parents, \
>> +							      &ccu_mux_closest_ops, \
>> +							      _flags),	\
>> +			.features	= CCU_FEATURE_CLOSEST_RATE,	\
>> +		}							\
>> +	}
>> +
>
> I'm fine with that one, but like we discussed on the NM (I think?) patch
> already, this creates some clocks and macros that will use the feature
> as a flag, and some will encode it into their name.
>
> Given that we need it here too, I'm really inclined to prefer what you
> did there, and thus create a new macro for pll-video0 instead of
> modifying the existing one.

Ok. Just to be clear: What I did in this patch is fine and I should use
the same approach for NM. Did I get that right?

Thanks,
  Frank

>
> Maxime
>
> [[End of PGP Signed Part]]
  

On Mon, Jul 03, 2023 at 11:17:24AM +0200, Frank Oltmanns wrote:
> 
> On 2023-07-03 at 09:38:48 +0200, Maxime Ripard <maxime@cerno.tech> wrote:
> > [[PGP Signed Part:Undecided]]
> > On Sun, Jul 02, 2023 at 07:55:25PM +0200, Frank Oltmanns wrote:
> >> When finding the best rate for a mux clock, consider rates that are
> >> higher than the requested rate by introducing a new clk_ops structure
> >> that uses the existing __clk_mux_determine_rate_closest function.
> >> Furthermore introduce an initialization macro that uses this new
> >> structure.
> >>
> >> Signed-off-by: Frank Oltmanns <frank@oltmanns.dev>
> >> ---
> >>  drivers/clk/sunxi-ng/ccu_mux.c | 13 +++++++++++++
> >>  drivers/clk/sunxi-ng/ccu_mux.h | 17 +++++++++++++++++
> >>  2 files changed, 30 insertions(+)
> >>
> >> diff --git a/drivers/clk/sunxi-ng/ccu_mux.c b/drivers/clk/sunxi-ng/ccu_mux.c
> >> index 8594d6a4addd..49a592bdeacf 100644
> >> --- a/drivers/clk/sunxi-ng/ccu_mux.c
> >> +++ b/drivers/clk/sunxi-ng/ccu_mux.c
> >> @@ -264,6 +264,19 @@ static unsigned long ccu_mux_recalc_rate(struct clk_hw *hw,
> >>  					   parent_rate);
> >>  }
> >>
> >> +const struct clk_ops ccu_mux_closest_ops = {
> >> +	.disable	= ccu_mux_disable,
> >> +	.enable		= ccu_mux_enable,
> >> +	.is_enabled	= ccu_mux_is_enabled,
> >> +
> >> +	.get_parent	= ccu_mux_get_parent,
> >> +	.set_parent	= ccu_mux_set_parent,
> >> +
> >> +	.determine_rate	= __clk_mux_determine_rate_closest,
> >> +	.recalc_rate	= ccu_mux_recalc_rate,
> >> +};
> >> +EXPORT_SYMBOL_NS_GPL(ccu_mux_closest_ops, SUNXI_CCU);
> >> +
> >
> > This is also a bit inconsistent with the other clocks: most (all?) of
> > them will simply handle this through a flag, but this one requires a new
> > set of clk_ops as well?
> >
> > I think we should create our own wrapper here around
> > __clk_mux_determine_rate and either call
> > __clk_mux_determine_rate_closest or __clk_mux_determine_rate depending
> > on the state of the flags, or call __clk_mux_determine_rate_flags with
> > the proper flags set for our clock.
> >
> > The former is probably slightly simpler.
> 
> Ok, I will address that in v4.
> 
> >
> >>  const struct clk_ops ccu_mux_ops = {
> >>  	.disable	= ccu_mux_disable,
> >>  	.enable		= ccu_mux_enable,
> >> diff --git a/drivers/clk/sunxi-ng/ccu_mux.h b/drivers/clk/sunxi-ng/ccu_mux.h
> >> index 2c1811a445b0..c4ee14e43719 100644
> >> --- a/drivers/clk/sunxi-ng/ccu_mux.h
> >> +++ b/drivers/clk/sunxi-ng/ccu_mux.h
> >> @@ -46,6 +46,22 @@ struct ccu_mux {
> >>  	struct ccu_common	common;
> >>  };
> >>
> >> +#define SUNXI_CCU_MUX_TABLE_WITH_GATE_CLOSEST(_struct, _name, _parents, _table,	\
> >> +				     _reg, _shift, _width, _gate,	\
> >> +				     _flags)				\
> >> +	struct ccu_mux _struct = {					\
> >> +		.enable	= _gate,					\
> >> +		.mux	= _SUNXI_CCU_MUX_TABLE(_shift, _width, _table),	\
> >> +		.common	= {						\
> >> +			.reg		= _reg,				\
> >> +			.hw.init	= CLK_HW_INIT_PARENTS(_name,	\
> >> +							      _parents, \
> >> +							      &ccu_mux_closest_ops, \
> >> +							      _flags),	\
> >> +			.features	= CCU_FEATURE_CLOSEST_RATE,	\
> >> +		}							\
> >> +	}
> >> +
> >
> > I'm fine with that one, but like we discussed on the NM (I think?) patch
> > already, this creates some clocks and macros that will use the feature
> > as a flag, and some will encode it into their name.
> >
> > Given that we need it here too, I'm really inclined to prefer what you
> > did there, and thus create a new macro for pll-video0 instead of
> > modifying the existing one.
> 
> Ok. Just to be clear: What I did in this patch is fine and I should use
> the same approach for NM. Did I get that right?

Yes. Leave the NM macro as it is, and add a new _CLOSEST variant that
sets the flag like you did there.

Maxime