Re: [STLinux Kernel] [PATCH 02/11] drivers: clk: st: Add clock propagation for audio clocks

2016-05-30 Thread Gabriel Fernandez
On 27 May 2016 at 17:41, Rob Herring  wrote:
> On Fri, May 27, 2016 at 09:23:20AM +0200, loic pallardy wrote:
>>
>>
>> On 05/26/2016 03:20 PM, Rob Herring wrote:
>> >On Thu, May 26, 2016 at 8:05 AM, loic pallardy  wrote:
>> >>
>> >>
>> >>On 05/26/2016 02:46 PM, Rob Herring wrote:
>> >>>
>> >>>On Thu, May 26, 2016 at 4:49 AM, Gabriel Fernandez
>> >>> wrote:
>> 
>> On 25 May 2016 at 19:24, Rob Herring  wrote:
>> >
>> >
>> >On Wed, May 18, 2016 at 10:41:23AM +0200, Gabriel Fernandez wrote:
>> >>
>> >>This patch allows fine tuning of the quads FS for audio clocks
>> >>accuracy.
>> >>
>
>> >>>
>> >>>That is no different and suffers the same point I raised. It requires
>> >>>updating the DT for any clock configuration change or enhancement.
>> >>>
>> >>Agree with you, DT update is needed as soon as a clock configuration should
>> >>be changed. This is due to STiH clock driver design based on DT description
>> >>of SoC clock tree.
>> >>
>> >>This clock driver was accepted 2 years ago. At the time being there was
>> >>discussion about clock tree description location: driver or DT.
>> >>Bad choice was done for this driver...
>> >>
>> >>If we decide to redesign STiH clock driver using in-driver clock tree
>> >>description, this will modify STiH clock DT nodes description and so break
>> >>DT backward compatibility.
>> >>
>> >>What's from your pov the best option?
>> >
>> >You can break it once or every time you need a clock change. I'd go
>> >with the former. Maybe more specific compatible strings throughout
>> >alone would be enough rather than a flag day changing the binding.
>>
>> So if I understand you correctly, main issue is d0 and d2 signification.
>> d0 and d2 are indeed location of the flexgen in the SoC. But that's right
>> flexgen are dedicated to clocks generation for features (system, audio,
>> video).
>> What about "st,flexgen-audio" and "st,flexgen-video"?
>
> It is not so much the name of these 2, but whether there are other cases
> for different clock nodes that could need the same thing. If so, update
> them all now rather than 1 by 1.
>
> Rob

Hi Rob,
Ok i will send a V2 for that.

Mike,
the first patch "drivers: clk: st: Add fs660c32 synthesizer algorithm"  can
be taken into account regardless the remark of Rob. Can you have a look ?

Thanks.
Best Regards

Gabriel


Re: [STLinux Kernel] [PATCH 02/11] drivers: clk: st: Add clock propagation for audio clocks

2016-05-27 Thread Rob Herring
On Fri, May 27, 2016 at 09:23:20AM +0200, loic pallardy wrote:
> 
> 
> On 05/26/2016 03:20 PM, Rob Herring wrote:
> >On Thu, May 26, 2016 at 8:05 AM, loic pallardy  wrote:
> >>
> >>
> >>On 05/26/2016 02:46 PM, Rob Herring wrote:
> >>>
> >>>On Thu, May 26, 2016 at 4:49 AM, Gabriel Fernandez
> >>> wrote:
> 
> On 25 May 2016 at 19:24, Rob Herring  wrote:
> >
> >
> >On Wed, May 18, 2016 at 10:41:23AM +0200, Gabriel Fernandez wrote:
> >>
> >>This patch allows fine tuning of the quads FS for audio clocks
> >>accuracy.
> >>

> >>>
> >>>That is no different and suffers the same point I raised. It requires
> >>>updating the DT for any clock configuration change or enhancement.
> >>>
> >>Agree with you, DT update is needed as soon as a clock configuration should
> >>be changed. This is due to STiH clock driver design based on DT description
> >>of SoC clock tree.
> >>
> >>This clock driver was accepted 2 years ago. At the time being there was
> >>discussion about clock tree description location: driver or DT.
> >>Bad choice was done for this driver...
> >>
> >>If we decide to redesign STiH clock driver using in-driver clock tree
> >>description, this will modify STiH clock DT nodes description and so break
> >>DT backward compatibility.
> >>
> >>What's from your pov the best option?
> >
> >You can break it once or every time you need a clock change. I'd go
> >with the former. Maybe more specific compatible strings throughout
> >alone would be enough rather than a flag day changing the binding.
> 
> So if I understand you correctly, main issue is d0 and d2 signification.
> d0 and d2 are indeed location of the flexgen in the SoC. But that's right
> flexgen are dedicated to clocks generation for features (system, audio,
> video).
> What about "st,flexgen-audio" and "st,flexgen-video"?

It is not so much the name of these 2, but whether there are other cases 
for different clock nodes that could need the same thing. If so, update 
them all now rather than 1 by 1.

Rob


Re: [STLinux Kernel] [PATCH 02/11] drivers: clk: st: Add clock propagation for audio clocks

2016-05-27 Thread loic pallardy



On 05/26/2016 03:20 PM, Rob Herring wrote:

On Thu, May 26, 2016 at 8:05 AM, loic pallardy  wrote:



On 05/26/2016 02:46 PM, Rob Herring wrote:


On Thu, May 26, 2016 at 4:49 AM, Gabriel Fernandez
 wrote:


On 25 May 2016 at 19:24, Rob Herring  wrote:



On Wed, May 18, 2016 at 10:41:23AM +0200, Gabriel Fernandez wrote:


This patch allows fine tuning of the quads FS for audio clocks
accuracy.

Signed-off-by: Olivier Bideau 
Signed-off-by: Gabriel Fernandez 
---
   .../devicetree/bindings/clock/st/st,flexgen.txt|  1 +
   drivers/clk/st/clk-flexgen.c   | 24
++
   2 files changed, 25 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
b/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
index b7ee5c7..15b33c7 100644
--- a/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
+++ b/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
@@ -60,6 +60,7 @@ This binding uses the common clock binding[2].
   Required properties:
   - compatible : shall be:
 "st,flexgen"
+  "st,stih407-clkgend0", "st,flexgen" (enable clock propagation on
parent)



What do "d0" and "d2" refer to?

This seems to indicate you have too much clock detail in the DT (with
individual clocks described) or not enough with genericish compatible
strings. What happens for the mext clock you need to adjust the flags
on? You should be able to make these adjustments without DT updates.
Perhaps you need a wider fixing of clock compatible strings.

Rob



Sorry i sent my response in html...

Hi Rob,

Thanks for reviewing.

Can i remove
"
st,stih407-clkgend0" & "
st,stih407-clkgend2" compatible strings and add proprieties instead ?
I only need to activate 2 features and then we can keep generic
compatible strings.




Hi Rob,


That is no different and suffers the same point I raised. It requires
updating the DT for any clock configuration change or enhancement.


Agree with you, DT update is needed as soon as a clock configuration should
be changed. This is due to STiH clock driver design based on DT description
of SoC clock tree.

This clock driver was accepted 2 years ago. At the time being there was
discussion about clock tree description location: driver or DT.
Bad choice was done for this driver...

If we decide to redesign STiH clock driver using in-driver clock tree
description, this will modify STiH clock DT nodes description and so break
DT backward compatibility.

What's from your pov the best option?


You can break it once or every time you need a clock change. I'd go
with the former. Maybe more specific compatible strings throughout
alone would be enough rather than a flag day changing the binding.


So if I understand you correctly, main issue is d0 and d2 signification.
d0 and d2 are indeed location of the flexgen in the SoC. But that's 
right flexgen are dedicated to clocks generation for features (system, 
audio, video).

What about "st,flexgen-audio" and "st,flexgen-video"?

BR,
Loic



Rob



Re: [STLinux Kernel] [PATCH 02/11] drivers: clk: st: Add clock propagation for audio clocks

2016-05-26 Thread Rob Herring
On Thu, May 26, 2016 at 8:05 AM, loic pallardy  wrote:
>
>
> On 05/26/2016 02:46 PM, Rob Herring wrote:
>>
>> On Thu, May 26, 2016 at 4:49 AM, Gabriel Fernandez
>>  wrote:
>>>
>>> On 25 May 2016 at 19:24, Rob Herring  wrote:


 On Wed, May 18, 2016 at 10:41:23AM +0200, Gabriel Fernandez wrote:
>
> This patch allows fine tuning of the quads FS for audio clocks
> accuracy.
>
> Signed-off-by: Olivier Bideau 
> Signed-off-by: Gabriel Fernandez 
> ---
>   .../devicetree/bindings/clock/st/st,flexgen.txt|  1 +
>   drivers/clk/st/clk-flexgen.c   | 24
> ++
>   2 files changed, 25 insertions(+)
>
> diff --git a/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
> b/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
> index b7ee5c7..15b33c7 100644
> --- a/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
> +++ b/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
> @@ -60,6 +60,7 @@ This binding uses the common clock binding[2].
>   Required properties:
>   - compatible : shall be:
> "st,flexgen"
> +  "st,stih407-clkgend0", "st,flexgen" (enable clock propagation on
> parent)


 What do "d0" and "d2" refer to?

 This seems to indicate you have too much clock detail in the DT (with
 individual clocks described) or not enough with genericish compatible
 strings. What happens for the mext clock you need to adjust the flags
 on? You should be able to make these adjustments without DT updates.
 Perhaps you need a wider fixing of clock compatible strings.

 Rob
>>>
>>>
>>> Sorry i sent my response in html...
>>>
>>> Hi Rob,
>>>
>>> Thanks for reviewing.
>>>
>>> Can i remove
>>> "
>>> st,stih407-clkgend0" & "
>>> st,stih407-clkgend2" compatible strings and add proprieties instead ?
>>> I only need to activate 2 features and then we can keep generic
>>> compatible strings.
>>
>>
> Hi Rob,
>>
>> That is no different and suffers the same point I raised. It requires
>> updating the DT for any clock configuration change or enhancement.
>>
> Agree with you, DT update is needed as soon as a clock configuration should
> be changed. This is due to STiH clock driver design based on DT description
> of SoC clock tree.
>
> This clock driver was accepted 2 years ago. At the time being there was
> discussion about clock tree description location: driver or DT.
> Bad choice was done for this driver...
>
> If we decide to redesign STiH clock driver using in-driver clock tree
> description, this will modify STiH clock DT nodes description and so break
> DT backward compatibility.
>
> What's from your pov the best option?

You can break it once or every time you need a clock change. I'd go
with the former. Maybe more specific compatible strings throughout
alone would be enough rather than a flag day changing the binding.

Rob


Re: [STLinux Kernel] [PATCH 02/11] drivers: clk: st: Add clock propagation for audio clocks

2016-05-26 Thread loic pallardy



On 05/26/2016 02:46 PM, Rob Herring wrote:

On Thu, May 26, 2016 at 4:49 AM, Gabriel Fernandez
 wrote:

On 25 May 2016 at 19:24, Rob Herring  wrote:


On Wed, May 18, 2016 at 10:41:23AM +0200, Gabriel Fernandez wrote:

This patch allows fine tuning of the quads FS for audio clocks
accuracy.

Signed-off-by: Olivier Bideau 
Signed-off-by: Gabriel Fernandez 
---
  .../devicetree/bindings/clock/st/st,flexgen.txt|  1 +
  drivers/clk/st/clk-flexgen.c   | 24 ++
  2 files changed, 25 insertions(+)

diff --git a/Documentation/devicetree/bindings/clock/st/st,flexgen.txt 
b/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
index b7ee5c7..15b33c7 100644
--- a/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
+++ b/Documentation/devicetree/bindings/clock/st/st,flexgen.txt
@@ -60,6 +60,7 @@ This binding uses the common clock binding[2].
  Required properties:
  - compatible : shall be:
"st,flexgen"
+  "st,stih407-clkgend0", "st,flexgen" (enable clock propagation on parent)


What do "d0" and "d2" refer to?

This seems to indicate you have too much clock detail in the DT (with
individual clocks described) or not enough with genericish compatible
strings. What happens for the mext clock you need to adjust the flags
on? You should be able to make these adjustments without DT updates.
Perhaps you need a wider fixing of clock compatible strings.

Rob


Sorry i sent my response in html...

Hi Rob,

Thanks for reviewing.

Can i remove
"
st,stih407-clkgend0" & "
st,stih407-clkgend2" compatible strings and add proprieties instead ?
I only need to activate 2 features and then we can keep generic
compatible strings.



Hi Rob,

That is no different and suffers the same point I raised. It requires
updating the DT for any clock configuration change or enhancement.

Agree with you, DT update is needed as soon as a clock configuration 
should be changed. This is due to STiH clock driver design based on DT 
description of SoC clock tree.


This clock driver was accepted 2 years ago. At the time being there was 
discussion about clock tree description location: driver or DT.

Bad choice was done for this driver...

If we decide to redesign STiH clock driver using in-driver clock tree 
description, this will modify STiH clock DT nodes description and so 
break DT backward compatibility.


What's from your pov the best option?

Regards,
Loic


Rob

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