Re: [PATCH] ARM: dts: aspeed: Add device tree for Ampere's Mt. Jefferson BMC

[Chanh Nguyen]

On 17/10/2024 07:08, Andrew Jeffery wrote:
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>
>
> Hi Chanh,
>
> On Wed, 2024-10-16 at 17:26 +0700, Chanh Nguyen wrote:
> > On 16/10/2024 12:07, Andrew Jeffery wrote:
> > > You can also find discussions where other maintainers (Guenter, hwmon
> > > maintainer; Krzysztof, devicetree maintainer) have asked that "pmbus"
> > > not be used as a compatible:
> > >
> > > https://lore.kernel.org/all/f76798ea-6edd-4888-8057-c09aaed88f25@xxxxxxxxxxxx/
> >
> > Hi Andrew,
> > I checked the discussion at
> > https://lore.kernel.org/all/f76798ea-6edd-4888-8057-c09aaed88f25@xxxxxxxxxxxx/
> > . It seems the maintainers don't want to use the "pmbus" compatible for
> > specific devices. The maintaners require an explicitly compatible from
> > device list in drivers/hwmon/pmbus/pmbus.c .
>
> There are two problems:
>
> 1. Describing your _hardware_ (not drivers) in the devicetree
> 2. Binding a driver to your device
>
> You ultimately care about both 1 and 2 as you want Linux to do
> something useful with the device, but for the purpose of this patch
> adding the devicetree, 1 is what matters and 2 is not really a part of
> the considerations.
>
> What needs to be the case is that the devicetree describes the device
> via an appropriate compatible string for the device (manufacturer and
> part number). Prior to that, the compatible string for the device needs
> to be documented in a devicetree binding. This may be the trivial-
> devices binding if there are no extra properties that need to be
> described, or you may need to write your own binding document for the
> device if it's more complex and one doesn't yet exist.
>
> So whatever is in pmbus.c needs to be fixed later on if your device is
> not yet supported by it, but that's a separate problem (2) to the
> problem you have here (1).
>
> Who is the manufacturer and what is the part number?
>
>
> Andrew

Thank Andrew for your explanation! I'm so happy to receive comments from 
you.

I'll remove the PSU node with "pmbus" compatible in the patch v2. We'll 
discuss more to have a suitable PSU node later.

I'm preparing the patch v2. Summary, I need to update as the below list.
1. Add Mt. Jefferson board compatible binding as Krzysztof pointed.
2. Remove the PSU node with "pmbus" compatible.

If you have any other comments on patch v1 please don't hesitate to 
point out; I'll update that in patch v2.

Regards,
Chanh