Re: [PATCH 04/10] dt-bindings: interrupt-controller: Add i.MX8qxp Display Controller interrupt controller

[Liu Ying]

On 07/08/2024, Krzysztof Kozlowski wrote:
> On 08/07/2024 08:51, Liu Ying wrote:
>> On 07/07/2024, Krzysztof Kozlowski wrote:
>>> On 05/07/2024 11:09, Liu Ying wrote:
>>>> i.MX8qxp Display Controller has a built-in interrupt controller to support
>>>> Enable/Status/Preset/Clear interrupt bit.
>>>>
>>>> Signed-off-by: Liu Ying <victor.liu@xxxxxxx>
>>>> ---
>>>>  .../fsl,imx8qxp-dc-intc.yaml                  | 321 ++++++++++++++++++
>>>>  1 file changed, 321 insertions(+)
>>>>  create mode 100644 Documentation/devicetree/bindings/interrupt-controller/fsl,imx8qxp-dc-intc.yaml
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/interrupt-controller/fsl,imx8qxp-dc-intc.yaml b/Documentation/devicetree/bindings/interrupt-controller/fsl,imx8qxp-dc-intc.yaml
>>>> new file mode 100644
>>>> index 000000000000..3d0d11def505
>>>> --- /dev/null
>>>> +++ b/Documentation/devicetree/bindings/interrupt-controller/fsl,imx8qxp-dc-intc.yaml
>>>> @@ -0,0 +1,321 @@
>>>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>>>> +%YAML 1.2
>>>> +---
>>>> +$id: http://devicetree.org/schemas/interrupt-controller/fsl,imx8qxp-dc-intc.yaml#
>>>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>>>> +
>>>> +title: Freescale i.MX8qxp Display Controller interrupt controller
>>>> +
>>>> +description: |
>>>> +  The Display Controller has a built-in interrupt controller with the following
>>>> +  features for all relevant HW events:
>>>> +
>>>> +  * Enable bit (mask)
>>>> +  * Status bit (set by an HW event)
>>>> +  * Preset bit (can be used by SW to set status)
>>>> +  * Clear bit (used by SW to reset the status)
>>>
>>> 1. Why this is split from the main node?
>>
>> Maxime suggested to do so:
>>
>> "
>> But at least the CRTC and the interrupt controller should be split away,
>> or explained and detailed far better than "well it's just convenient".
>> "
>>
>> https://lore.kernel.org/lkml/2k3cc3yfwqlpquxrdmzmaafz55b3lnqomzxjsvtetfriliqj3k@tv6uh7dzc2ea/
>>
>>>
>>> 2. Who can use this interrupt controller? Children of your display unit?
>>
>> Yes, only devices in the main display controller use it.
>>
>>> Then it is not really a separate device, is it?
>>
>> Er, per Maxime, it is a separate device.
> 
> It's not for me, especially considering small register region used here.

Maxime, can you please chime in to discuss whether the interrupt controller
is a separate device?

Maybe register region size doesn't matter.

> 
> Srsly, with that claim, some I2C device like PMIC also has a separate
> interrupt controller, because interrupts are in separate few registers
> (e.g. status, mask and ack).
> 
> Can any of the children interrupts be routed differently?

No, I don't think they can.

> 
> Post entire, complete DTS for review.

Will do that in v2.

> 
> Best regards,
> Krzysztof
> 
> 

-- 
Regards,
Liu Ying