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[PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional input reference clock for PLL1

Swapnil Jakhade posted 5 patches 2 years ago
There is a newer version of this series
[PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional input reference clock for PLL1
Posted by Swapnil Jakhade 2 years ago 
Torrent PHY can have two input reference clocks. Update bindings
to support dual reference clock multilink configurations.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
---
 .../devicetree/bindings/phy/phy-cadence-torrent.yaml        | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml b/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
index dfb31314face..98946f549895 100644
--- a/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
+++ b/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
@@ -35,14 +35,14 @@ properties:
     minItems: 1
     maxItems: 2
     description:
-      PHY reference clock for 1 item. Must contain an entry in clock-names.
-      Optional Parent to enable output reference clock.
+      PHY input reference clocks - refclk & pll1_refclk (optional).
+      Optional Parent to enable output reference clock (phy_en_refclk).
 
   clock-names:
     minItems: 1
     items:
       - const: refclk
-      - const: phy_en_refclk
+      - enum: [ pll1_refclk, phy_en_refclk ]
 
   reg:
     minItems: 1
-- 
2.25.1
Re: [PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional input reference clock for PLL1
Posted by Krzysztof Kozlowski 2 years ago 
On 12/12/2023 12:48, Swapnil Jakhade wrote:
> Torrent PHY can have two input reference clocks. Update bindings

It already supports two.

> to support dual reference clock multilink configurations.
> 
> Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
> ---
>  .../devicetree/bindings/phy/phy-cadence-torrent.yaml        | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml b/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
> index dfb31314face..98946f549895 100644
> --- a/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
> +++ b/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
> @@ -35,14 +35,14 @@ properties:
>      minItems: 1
>      maxItems: 2
>      description:
> -      PHY reference clock for 1 item. Must contain an entry in clock-names.
> -      Optional Parent to enable output reference clock.
> +      PHY input reference clocks - refclk & pll1_refclk (optional).
> +      Optional Parent to enable output reference clock (phy_en_refclk).

So third clock? But you allow only two? Confusing.

>  
>    clock-names:
>      minItems: 1
>      items:
>        - const: refclk
> -      - const: phy_en_refclk
> +      - enum: [ pll1_refclk, phy_en_refclk ]

This does not match your commit msg. You already had two clocks there.

Best regards,
Krzysztof
RE: [PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional input reference clock for PLL1
Posted by Swapnil Kashinath Jakhade 2 years ago 
Hi Krzysztof,

> -----Original Message-----
> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Sent: Wednesday, December 13, 2023 12:19 PM
> To: Swapnil Kashinath Jakhade <sjakhade@cadence.com>; vkoul@kernel.org;
> kishon@kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org;
> conor+dt@kernel.org; linux-phy@lists.infradead.org; linux-
> kernel@vger.kernel.org; devicetree@vger.kernel.org
> Cc: Milind Parab <mparab@cadence.com>; rogerq@kernel.org; s-
> vadapalli@ti.com
> Subject: Re: [PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional
> input reference clock for PLL1
> 
> EXTERNAL MAIL
> 
> 
> On 12/12/2023 12:48, Swapnil Jakhade wrote:
> > Torrent PHY can have two input reference clocks. Update bindings
> 
> It already supports two.
> 

Thanks for your comments.
refclk and pll1_refclk are the two input reference clocks for the PLLs.
phy_en_refclk is used to enable output reference clock in some cases.

> > to support dual reference clock multilink configurations.
> >
> > Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
> > ---
> >  .../devicetree/bindings/phy/phy-cadence-torrent.yaml        | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/Documentation/devicetree/bindings/phy/phy-cadence-
> torrent.yaml b/Documentation/devicetree/bindings/phy/phy-cadence-
> torrent.yaml
> > index dfb31314face..98946f549895 100644
> > --- a/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
> > +++ b/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
> > @@ -35,14 +35,14 @@ properties:
> >      minItems: 1
> >      maxItems: 2
> >      description:
> > -      PHY reference clock for 1 item. Must contain an entry in clock-names.
> > -      Optional Parent to enable output reference clock.
> > +      PHY input reference clocks - refclk & pll1_refclk (optional).
> > +      Optional Parent to enable output reference clock (phy_en_refclk).
> 
> So third clock? But you allow only two? Confusing.
>

Yes, if both refclk and pll1_refclk are present, phy_en_refclk can't be used.

> >
> >    clock-names:
> >      minItems: 1
> >      items:
> >        - const: refclk
> > -      - const: phy_en_refclk
> > +      - enum: [ pll1_refclk, phy_en_refclk ]
> 
> This does not match your commit msg. You already had two clocks there.
> 
Yes, but refclk was the single input reference clock used for PLLs earlier.
As stated in commit message, a new input reference clock (pll1_refclk) is added here.

Thanks & regards,
Swapnil

> Best regards,
> Krzysztof
Re: [PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional input reference clock for PLL1
Posted by Krzysztof Kozlowski 2 years ago 
On 14/12/2023 08:02, Swapnil Kashinath Jakhade wrote:
> Hi Krzysztof,
> 
>> -----Original Message-----
>> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> Sent: Wednesday, December 13, 2023 12:19 PM
>> To: Swapnil Kashinath Jakhade <sjakhade@cadence.com>; vkoul@kernel.org;
>> kishon@kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org;
>> conor+dt@kernel.org; linux-phy@lists.infradead.org; linux-
>> kernel@vger.kernel.org; devicetree@vger.kernel.org
>> Cc: Milind Parab <mparab@cadence.com>; rogerq@kernel.org; s-
>> vadapalli@ti.com
>> Subject: Re: [PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional
>> input reference clock for PLL1
>>
>> EXTERNAL MAIL
>>
>>
>> On 12/12/2023 12:48, Swapnil Jakhade wrote:
>>> Torrent PHY can have two input reference clocks. Update bindings
>>
>> It already supports two.
>>
> 
> Thanks for your comments.
> refclk and pll1_refclk are the two input reference clocks for the PLLs.
> phy_en_refclk is used to enable output reference clock in some cases.

Why input clock is used to enable output reference clock?

> 
>>> to support dual reference clock multilink configurations.
>>>
>>> Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
>>> ---
>>>  .../devicetree/bindings/phy/phy-cadence-torrent.yaml        | 6 +++---
>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/phy/phy-cadence-
>> torrent.yaml b/Documentation/devicetree/bindings/phy/phy-cadence-
>> torrent.yaml
>>> index dfb31314face..98946f549895 100644
>>> --- a/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
>>> +++ b/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
>>> @@ -35,14 +35,14 @@ properties:
>>>      minItems: 1
>>>      maxItems: 2
>>>      description:
>>> -      PHY reference clock for 1 item. Must contain an entry in clock-names.
>>> -      Optional Parent to enable output reference clock.
>>> +      PHY input reference clocks - refclk & pll1_refclk (optional).
>>> +      Optional Parent to enable output reference clock (phy_en_refclk).
>>
>> So third clock? But you allow only two? Confusing.
>>
> 
> Yes, if both refclk and pll1_refclk are present, phy_en_refclk can't be used.
> 
>>>
>>>    clock-names:
>>>      minItems: 1
>>>      items:
>>>        - const: refclk
>>> -      - const: phy_en_refclk
>>> +      - enum: [ pll1_refclk, phy_en_refclk ]
>>
>> This does not match your commit msg. You already had two clocks there.
>>
> Yes, but refclk was the single input reference clock used for PLLs earlier.
> As stated in commit message, a new input reference clock (pll1_refclk) is added here.

existing phy_en_refclk is also input reference clock, isn't it?

> 

Best regards,
Krzysztof
Re: [PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional input reference clock for PLL1
Posted by Roger Quadros 2 years ago 
On 14/12/2023 09:22, Krzysztof Kozlowski wrote:
> On 14/12/2023 08:02, Swapnil Kashinath Jakhade wrote:
>> Hi Krzysztof,
>>
>>> -----Original Message-----
>>> From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>>> Sent: Wednesday, December 13, 2023 12:19 PM
>>> To: Swapnil Kashinath Jakhade <sjakhade@cadence.com>; vkoul@kernel.org;
>>> kishon@kernel.org; robh+dt@kernel.org; krzysztof.kozlowski+dt@linaro.org;
>>> conor+dt@kernel.org; linux-phy@lists.infradead.org; linux-
>>> kernel@vger.kernel.org; devicetree@vger.kernel.org
>>> Cc: Milind Parab <mparab@cadence.com>; rogerq@kernel.org; s-
>>> vadapalli@ti.com
>>> Subject: Re: [PATCH v2 1/5] dt-bindings: phy: cadence-torrent: Add optional
>>> input reference clock for PLL1
>>>
>>> EXTERNAL MAIL
>>>
>>>
>>> On 12/12/2023 12:48, Swapnil Jakhade wrote:
>>>> Torrent PHY can have two input reference clocks. Update bindings
>>>
>>> It already supports two.
>>>
>>
>> Thanks for your comments.
>> refclk and pll1_refclk are the two input reference clocks for the PLLs.
>> phy_en_refclk is used to enable output reference clock in some cases.
> 
> Why input clock is used to enable output reference clock?

Looking at the driver code, "phy_en_refclk" is used at 2 places only to
set the parent of 2 clocks apparently called "received reference clock"
and "derived reference clock", either of which can be used to enable an
optional reference clock output feature.

My understanding is that it is a separate refclk input than 'refclk' (pll0)
or 'pll1_refclk' which can be used to enable a reference clock output feature.

So this PHY can support a total of 3 input reference clocks:
"refclk" is PLL0 reference clock and is required on all platforms
"pll1_refclk" is PLL1 reference clock and is required on some platforms
"phy_en_refclk" is reference for output reference clock generator and is optional on all platforms

Swapnil, can you please confirm my understanding? Thanks!

> 
>>
>>>> to support dual reference clock multilink configurations.
>>>>
>>>> Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
>>>> ---
>>>>  .../devicetree/bindings/phy/phy-cadence-torrent.yaml        | 6 +++---
>>>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/phy/phy-cadence-
>>> torrent.yaml b/Documentation/devicetree/bindings/phy/phy-cadence-
>>> torrent.yaml
>>>> index dfb31314face..98946f549895 100644
>>>> --- a/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
>>>> +++ b/Documentation/devicetree/bindings/phy/phy-cadence-torrent.yaml
>>>> @@ -35,14 +35,14 @@ properties:
>>>>      minItems: 1
>>>>      maxItems: 2
>>>>      description:
>>>> -      PHY reference clock for 1 item. Must contain an entry in clock-names.
>>>> -      Optional Parent to enable output reference clock.
>>>> +      PHY input reference clocks - refclk & pll1_refclk (optional).
>>>> +      Optional Parent to enable output reference clock (phy_en_refclk).
>>>
>>> So third clock? But you allow only two? Confusing.
>>>
>>
>> Yes, if both refclk and pll1_refclk are present, phy_en_refclk can't be used.
>>
>>>>
>>>>    clock-names:
>>>>      minItems: 1
>>>>      items:
>>>>        - const: refclk
>>>> -      - const: phy_en_refclk
>>>> +      - enum: [ pll1_refclk, phy_en_refclk ]
>>>
>>> This does not match your commit msg. You already had two clocks there.
>>>
>> Yes, but refclk was the single input reference clock used for PLLs earlier.
>> As stated in commit message, a new input reference clock (pll1_refclk) is added here.
> 
> existing phy_en_refclk is also input reference clock, isn't it?
> 
>>
> 
> Best regards,
> Krzysztof
> 

-- 
cheers,
-roger

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