Re: [PATCH 2/2] hwmon: (pmbus) Add driver for Analog Devices MAX20912 and MAX20916

[Guenter Roeck <linux@roeck-us.net>]

On 7/8/26 04:32, Nuno Sá wrote:
> On Wed, Jul 08, 2026 at 12:50:25PM +0200, Krzysztof Kozlowski wrote:
>> On Wed, Jul 08, 2026 at 10:19:56AM +0100, Nuno Sá wrote:
>>> On Tue, Jul 07, 2026 at 06:52:48AM -0700, Guenter Roeck wrote:
>>>> On 7/7/26 05:26, Fred Chen wrote:
>>>>> Add support for the Analog Devices MAX20912 and MAX20916 dual-output
>>>>> multiphase voltage regulators with PMBus interfaces.
>>>>>
>>>>> Signed-off-by: Fred Chen <fredchen.openbmc@gmail.com>
>>>>
>>>> Please provide evidence that those chips actually exist.
>>>> Internet search comes up blank. I'll need confirmation
>>>> from someone at Analog.
>>>
>>> Hi Guenter,
>>>
>>> Well, in fact I'm in the middle of preparing a series that adds support
>>> for:
>>>
>>> "max20826"
>>> "max20855b"
>>> "max20908"
>>> "max20912"
>>> "max20916"
>>>
>>> All the above parts have the datasheet under NDA. But before we had a
>>> one page "datasheet" in analog.com but I guess that is gone! For context
>>> I mainly did the base (core) driver for max20826 and then Alexis added
>>> the other ones.
>>>
>>> Not sure how to proceed... I can wait and then work on top of what Fred
>>> has but this patch is very minimal when compared with what we have.
>>> Like:
>>>
>>> * No regulator support;
>>> * No direct mode. The chip has two ways to access registers (paging and
>>> * direct mode).
>>> * No way to count how many phases we have or if RAIL_B (func[1]) is being used at
>>> all.
>>>
>>>
>>> Some other things more intriguing is that these chips, as far as I'm
>>> aware (at least for max20826), always have bit 2 set in ON_OFF_CONFIG so
>>> a gpio vout. Also we needed some special handling to read phase current
>>> which I'm not seeing in the driver. So I would like to understand how
>>> the chip was tested?
>>>
>>> Anyways, if Fred is ok with it I can just finish what I'm doing and send
>>> the patches. It would make sense to have something more complete on
>>> submission but I don't want to just "steal" the work already done.
>>
>> Binding should be in such case posted complete, so probably not a
>> trivial device.
> 
> Yes, in my series bindings are not in trivial as we support the enable
> gpios.
> 

Same question I asked before: What is your use case ?

Thanks,
Guenter