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

[Ciprian Marian Costea <ciprianmarian.costea@oss.nxp.com>]

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.