Re: [PATCH v2 1/2] dt-bindings: timer: thead,c900-aclint-mtimer: separate mtime and mtimecmp regs

From: Inochi Amaoto
Date: Tue Nov 14 2023 - 17:44:56 EST


>On Tue, Nov 14, 2023 at 09:45:33AM +0800, Inochi Amaoto wrote:
>>> On 2023/11/14 8:45, Inochi Amaoto wrote:
>>>> The timer registers of aclint don't follow the clint layout and can
>>>> be mapped on any different offset. As sg2042 uses separated timer
>>>> and mswi for its clint, it should follow the aclint spec and have
>>>> separated registers.
>>>>
>>>> The previous patch introduces a new type of T-HEAD aclint timer which
>>>> has clint timer layout. Although the timer has the clint layout, it
>>>> should follow the aclint spec and uses the separated mtime and mtimecmp
>>>> regs. So a ABI change is needed to make the timer fit the aclint spec.
>>>>
>>>> To make T-HEAD aclint timer more closer to the aclint spec, use two regs
>>>> to represent the mtime and mtimecmp.
>>>>
>>>> Signed-off-by: Inochi Amaoto <inochiama@xxxxxxxxxxx>
>>>> Fixes: 4734449f7311 ("dt-bindings: timer: Add Sophgo sg2042 CLINT timer")
>>>> Link: https://lists.infradead.org/pipermail/opensbi/2023-October/005693.html
>>>> Link: https://github.com/riscv/riscv-aclint/blob/main/riscv-aclint.adoc
>>>> ---
>>>> .../devicetree/bindings/timer/thead,c900-aclint-mtimer.yaml | 5 +++--
>>>> 1 file changed, 3 insertions(+), 2 deletions(-)
>>>>
>>>> diff --git a/Documentation/devicetree/bindings/timer/thead,c900-aclint-mtimer.yaml b/Documentation/devicetree/bindings/timer/thead,c900-aclint-mtimer.yaml
>>>> index fbd235650e52..c3080962d902 100644
>>>> --- a/Documentation/devicetree/bindings/timer/thead,c900-aclint-mtimer.yaml
>>>> +++ b/Documentation/devicetree/bindings/timer/thead,c900-aclint-mtimer.yaml
>>>> @@ -17,7 +17,7 @@ properties:
>>>> - const: thead,c900-aclint-mtimer
>>>>
>>>> reg:
>>>> - maxItems: 1
>>>> + maxItems: 2
>>>
>>> The first one is for mtime and the second one is for mtimecmp, right?
>>
>> Yes, that is right.
>>
>>> Recommend to add some comment in binding file to make it clear.
>>>
>>
>> Thanks for your advice.
>
>Sorry for not noticing that on v1 -

Sorry for this, I have seen the v1 and improve the comment of the v2. I
will give a feedback next time. Anyway, thank you for your advice in v1.

>you should indeed describe these in the binding, by using the items property.
>

Thanks, I will have a try.