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[PATCH 1/2] dt-bindings: linflexuart: add clock definitions

Ciprian Costea posted 2 patches 2 months ago
[PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Ciprian Costea 2 months ago 
From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>

Add clock definitions for NXP LINFlexD UART bindings
and update the binding examples with S32G2 node.

Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
---
 .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
index 4171f524a928..45fcab9e186d 100644
--- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
+++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
@@ -34,6 +34,14 @@ properties:
   interrupts:
     maxItems: 1
 
+  clocks:
+    maxItems: 2
+
+  clock-names:
+    items:
+      - const: ipg
+      - const: lin
+
 required:
   - compatible
   - reg
@@ -48,3 +56,16 @@ examples:
         reg = <0x40053000 0x1000>;
         interrupts = <0 59 4>;
     };
+
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    serial@401c8000 {
+        compatible = "nxp,s32g2-linflexuart",
+                     "fsl,s32v234-linflexuart";
+        reg = <0x401c8000 0x3000>;
+        interrupts = <GIC_SPI 82 IRQ_TYPE_EDGE_RISING>;
+        clocks = <&clks 14>, <&clks 13>;
+        clock-names = "lin", "ipg";
+    };
-- 
2.45.2
Re: [PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Conor Dooley 2 months ago 
On Tue, Sep 24, 2024 at 05:12:46PM +0300, Ciprian Costea wrote:
> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> 
> Add clock definitions for NXP LINFlexD UART bindings
> and update the binding examples with S32G2 node.
> 
> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> ---
>  .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
>  1 file changed, 21 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> index 4171f524a928..45fcab9e186d 100644
> --- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> +++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> @@ -34,6 +34,14 @@ properties:
>    interrupts:
>      maxItems: 1
>  
> +  clocks:
> +    maxItems: 2
> +
> +  clock-names:
> +    items:
> +      - const: ipg
> +      - const: lin

Can all devices have 2 clocks, or just the s32g2?

> +
>  required:
>    - compatible
>    - reg
> @@ -48,3 +56,16 @@ examples:
>          reg = <0x40053000 0x1000>;
>          interrupts = <0 59 4>;
>      };
> +
> +  - |
> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +
> +    serial@401c8000 {
> +        compatible = "nxp,s32g2-linflexuart",
> +                     "fsl,s32v234-linflexuart";
> +        reg = <0x401c8000 0x3000>;
> +        interrupts = <GIC_SPI 82 IRQ_TYPE_EDGE_RISING>;
> +        clocks = <&clks 14>, <&clks 13>;
> +        clock-names = "lin", "ipg";
> +    };
> -- 
> 2.45.2
>
Re: [PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Ciprian Marian Costea 2 months ago 
On 9/24/2024 5:24 PM, Conor Dooley wrote:
> On Tue, Sep 24, 2024 at 05:12:46PM +0300, Ciprian Costea wrote:
>> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>
>> Add clock definitions for NXP LINFlexD UART bindings
>> and update the binding examples with S32G2 node.
>>
>> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>> ---
>>   .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
>>   1 file changed, 21 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>> index 4171f524a928..45fcab9e186d 100644
>> --- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>> +++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>> @@ -34,6 +34,14 @@ properties:
>>     interrupts:
>>       maxItems: 1
>>   
>> +  clocks:
>> +    maxItems: 2
>> +
>> +  clock-names:
>> +    items:
>> +      - const: ipg
>> +      - const: lin
> 
> Can all devices have 2 clocks, or just the s32g2?
> 

Hello Conor,

All devices (S32G2, S32G3 and S32V234) have 2 clocks for LINFlexD module.
They are: "lin" which is the frequency of the baud clock and "ipg" which 
drives the access to the LINFlexD iomapped registers.


Best Regards,
Ciprian

>> +
>>   required:
>>     - compatible
>>     - reg
>> @@ -48,3 +56,16 @@ examples:
>>           reg = <0x40053000 0x1000>;
>>           interrupts = <0 59 4>;
>>       };
>> +
>> +  - |
>> +    #include <dt-bindings/interrupt-controller/arm-gic.h>
>> +    #include <dt-bindings/interrupt-controller/irq.h>
>> +
>> +    serial@401c8000 {
>> +        compatible = "nxp,s32g2-linflexuart",
>> +                     "fsl,s32v234-linflexuart";
>> +        reg = <0x401c8000 0x3000>;
>> +        interrupts = <GIC_SPI 82 IRQ_TYPE_EDGE_RISING>;
>> +        clocks = <&clks 14>, <&clks 13>;
>> +        clock-names = "lin", "ipg";
>> +    };
>> -- 
>> 2.45.2
>>
Re: [PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Conor Dooley 2 months ago 
On Tue, Sep 24, 2024 at 05:52:13PM +0300, Ciprian Marian Costea wrote:
> On 9/24/2024 5:24 PM, Conor Dooley wrote:
> > On Tue, Sep 24, 2024 at 05:12:46PM +0300, Ciprian Costea wrote:
> > > From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > > 
> > > Add clock definitions for NXP LINFlexD UART bindings
> > > and update the binding examples with S32G2 node.
> > > 
> > > Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > > ---
> > >   .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
> > >   1 file changed, 21 insertions(+)
> > > 
> > > diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > index 4171f524a928..45fcab9e186d 100644
> > > --- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > +++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > @@ -34,6 +34,14 @@ properties:
> > >     interrupts:
> > >       maxItems: 1
> > > +  clocks:
> > > +    maxItems: 2
> > > +
> > > +  clock-names:
> > > +    items:
> > > +      - const: ipg
> > > +      - const: lin
> > 
> > Can all devices have 2 clocks, or just the s32g2?
> > 
> 
> All devices (S32G2, S32G3 and S32V234) have 2 clocks for LINFlexD module.

I see. How come the driver is capable of working without them?

> They are: "lin" which is the frequency of the baud clock and "ipg" which
> drives the access to the LINFlexD iomapped registers.

It would be good to have an items list in the clocks property with that
information.
Re: [PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Ciprian Marian Costea 2 months ago 
On 9/24/2024 6:01 PM, Conor Dooley wrote:
> On Tue, Sep 24, 2024 at 05:52:13PM +0300, Ciprian Marian Costea wrote:
>> On 9/24/2024 5:24 PM, Conor Dooley wrote:
>>> On Tue, Sep 24, 2024 at 05:12:46PM +0300, Ciprian Costea wrote:
>>>> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>>>
>>>> Add clock definitions for NXP LINFlexD UART bindings
>>>> and update the binding examples with S32G2 node.
>>>>
>>>> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>>> ---
>>>>    .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
>>>>    1 file changed, 21 insertions(+)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>>>> index 4171f524a928..45fcab9e186d 100644
>>>> --- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>>>> +++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>>>> @@ -34,6 +34,14 @@ properties:
>>>>      interrupts:
>>>>        maxItems: 1
>>>> +  clocks:
>>>> +    maxItems: 2
>>>> +
>>>> +  clock-names:
>>>> +    items:
>>>> +      - const: ipg
>>>> +      - const: lin
>>>
>>> Can all devices have 2 clocks, or just the s32g2?
>>>
>>
>> All devices (S32G2, S32G3 and S32V234) have 2 clocks for LINFlexD module.
> 
> I see. How come the driver is capable of working without them?
> 

The driver was working because the LINFlexD clocks were configured and 
kept enabled by the downstream bootloader (TF-A and U-Boot). This is not 
ideal since LINFlexD Linux driver should manage those clocks 
independently and not rely on a previous bootloader configuration (hence 
the need for this current patchset).

>> They are: "lin" which is the frequency of the baud clock and "ipg" which
>> drives the access to the LINFlexD iomapped registers.
> 
> It would be good to have an items list in the clocks property with that
> information.

Thanks for this suggestion. I would add such information in V2.
Re: [PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Conor Dooley 2 months ago 
On Tue, Sep 24, 2024 at 06:17:11PM +0300, Ciprian Marian Costea wrote:
> On 9/24/2024 6:01 PM, Conor Dooley wrote:
> > On Tue, Sep 24, 2024 at 05:52:13PM +0300, Ciprian Marian Costea wrote:
> > > On 9/24/2024 5:24 PM, Conor Dooley wrote:
> > > > On Tue, Sep 24, 2024 at 05:12:46PM +0300, Ciprian Costea wrote:
> > > > > From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > > > > 
> > > > > Add clock definitions for NXP LINFlexD UART bindings
> > > > > and update the binding examples with S32G2 node.
> > > > > 
> > > > > Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > > > > ---
> > > > >    .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
> > > > >    1 file changed, 21 insertions(+)
> > > > > 
> > > > > diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > > > index 4171f524a928..45fcab9e186d 100644
> > > > > --- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > > > +++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > > > @@ -34,6 +34,14 @@ properties:
> > > > >      interrupts:
> > > > >        maxItems: 1
> > > > > +  clocks:
> > > > > +    maxItems: 2
> > > > > +
> > > > > +  clock-names:
> > > > > +    items:
> > > > > +      - const: ipg
> > > > > +      - const: lin
> > > > 
> > > > Can all devices have 2 clocks, or just the s32g2?
> > > > 
> > > 
> > > All devices (S32G2, S32G3 and S32V234) have 2 clocks for LINFlexD module.
> > 
> > I see. How come the driver is capable of working without them?
> > 
> 
> The driver was working because the LINFlexD clocks were configured and kept
> enabled by the downstream bootloader (TF-A and U-Boot). This is not ideal
> since LINFlexD Linux driver should manage those clocks independently and not
> rely on a previous bootloader configuration (hence the need for this current
> patchset).

I'd also mark them as required in the binding too, but the driver will
still have to account for them being missing, for backwards
compatibility reasons. Add a comment explaining the history to the
commit message when you do that.
Re: [PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Ciprian Marian Costea 2 months ago 
On 9/24/2024 6:27 PM, Conor Dooley wrote:
> On Tue, Sep 24, 2024 at 06:17:11PM +0300, Ciprian Marian Costea wrote:
>> On 9/24/2024 6:01 PM, Conor Dooley wrote:
>>> On Tue, Sep 24, 2024 at 05:52:13PM +0300, Ciprian Marian Costea wrote:
>>>> On 9/24/2024 5:24 PM, Conor Dooley wrote:
>>>>> On Tue, Sep 24, 2024 at 05:12:46PM +0300, Ciprian Costea wrote:
>>>>>> From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>>>>>
>>>>>> Add clock definitions for NXP LINFlexD UART bindings
>>>>>> and update the binding examples with S32G2 node.
>>>>>>
>>>>>> Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
>>>>>> ---
>>>>>>     .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
>>>>>>     1 file changed, 21 insertions(+)
>>>>>>
>>>>>> diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>>>>>> index 4171f524a928..45fcab9e186d 100644
>>>>>> --- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>>>>>> +++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
>>>>>> @@ -34,6 +34,14 @@ properties:
>>>>>>       interrupts:
>>>>>>         maxItems: 1
>>>>>> +  clocks:
>>>>>> +    maxItems: 2
>>>>>> +
>>>>>> +  clock-names:
>>>>>> +    items:
>>>>>> +      - const: ipg
>>>>>> +      - const: lin
>>>>>
>>>>> Can all devices have 2 clocks, or just the s32g2?
>>>>>
>>>>
>>>> All devices (S32G2, S32G3 and S32V234) have 2 clocks for LINFlexD module.
>>>
>>> I see. How come the driver is capable of working without them?
>>>
>>
>> The driver was working because the LINFlexD clocks were configured and kept
>> enabled by the downstream bootloader (TF-A and U-Boot). This is not ideal
>> since LINFlexD Linux driver should manage those clocks independently and not
>> rely on a previous bootloader configuration (hence the need for this current
>> patchset).
> 
> I'd also mark them as required in the binding too, but the driver will
> still have to account for them being missing, for backwards
> compatibility reasons. Add a comment explaining the history to the
> commit message when you do that.

Already in the second patch from this patchset the clocking support was 
added in the LINFlexD driver as optional, indeed for backwards 
compatibility.
I presumed that because of this optional clock enablement, I should not 
add the clocks as required in the bindings, but I will do so in V2. Thanks.
Re: [PATCH 1/2] dt-bindings: linflexuart: add clock definitions
Posted by Conor Dooley 2 months ago 
On Tue, Sep 24, 2024 at 06:32:30PM +0300, Ciprian Marian Costea wrote:
> On 9/24/2024 6:27 PM, Conor Dooley wrote:
> > On Tue, Sep 24, 2024 at 06:17:11PM +0300, Ciprian Marian Costea wrote:
> > > On 9/24/2024 6:01 PM, Conor Dooley wrote:
> > > > On Tue, Sep 24, 2024 at 05:52:13PM +0300, Ciprian Marian Costea wrote:
> > > > > On 9/24/2024 5:24 PM, Conor Dooley wrote:
> > > > > > On Tue, Sep 24, 2024 at 05:12:46PM +0300, Ciprian Costea wrote:
> > > > > > > From: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > > > > > > 
> > > > > > > Add clock definitions for NXP LINFlexD UART bindings
> > > > > > > and update the binding examples with S32G2 node.
> > > > > > > 
> > > > > > > Signed-off-by: Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>
> > > > > > > ---
> > > > > > >     .../bindings/serial/fsl,s32-linflexuart.yaml  | 21 +++++++++++++++++++
> > > > > > >     1 file changed, 21 insertions(+)
> > > > > > > 
> > > > > > > diff --git a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > > > > > index 4171f524a928..45fcab9e186d 100644
> > > > > > > --- a/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > > > > > +++ b/Documentation/devicetree/bindings/serial/fsl,s32-linflexuart.yaml
> > > > > > > @@ -34,6 +34,14 @@ properties:
> > > > > > >       interrupts:
> > > > > > >         maxItems: 1
> > > > > > > +  clocks:
> > > > > > > +    maxItems: 2
> > > > > > > +
> > > > > > > +  clock-names:
> > > > > > > +    items:
> > > > > > > +      - const: ipg
> > > > > > > +      - const: lin
> > > > > > 
> > > > > > Can all devices have 2 clocks, or just the s32g2?
> > > > > > 
> > > > > 
> > > > > All devices (S32G2, S32G3 and S32V234) have 2 clocks for LINFlexD module.
> > > > 
> > > > I see. How come the driver is capable of working without them?
> > > > 
> > > 
> > > The driver was working because the LINFlexD clocks were configured and kept
> > > enabled by the downstream bootloader (TF-A and U-Boot). This is not ideal
> > > since LINFlexD Linux driver should manage those clocks independently and not
> > > rely on a previous bootloader configuration (hence the need for this current
> > > patchset).
> > 
> > I'd also mark them as required in the binding too, but the driver will
> > still have to account for them being missing, for backwards
> > compatibility reasons. Add a comment explaining the history to the
> > commit message when you do that.
> 
> Already in the second patch from this patchset the clocking support was
> added in the LINFlexD driver as optional, indeed for backwards
> compatibility.

Oh great.

> I presumed that because of this optional clock enablement, I should not add
> the clocks as required in the bindings, but I will do so in V2. Thanks.

IMO required is correct, since it would not have worked properly if the
bootloader hadn't done the setup.

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