Re: [RFC PATCH v4 2/5] mfd: add driver for Marvell 88PM886 PMIC

From: Karel Balej
Date: Thu Mar 21 2024 - 15:14:43 EST


Mark Brown, 2024-03-21T19:00:24+00:00:
> On Thu, Mar 21, 2024 at 07:16:43PM +0100, Karel Balej wrote:
> > Mark Brown, 2024-03-21T17:48:28+00:00:
>
> > > > They do according to the downstream driver which is my only reference.
> > > > In fact, there the driver defines the configs separately for each regmap
> > > > but with the same values.
>
> > > This is a downstream driver - are you sure it's got the best code
> > > quality?
>
> > No, that is why I have rewritten it and tried to improve on this. But
> > like I said, it is my only reference. Is there some other way to verify
> > this value (besides perhaps the datasheet)?
>
> The maximum register is whatever the maximum register we know about for
> the device is, the datasheet is generally a good reference there.
>
> > > I'm not seeing any references to registers with numbers as high as the
> > > maximum register that's there in your driver for example.
>
> > Indeed, I have performed the same check with the same findings. But that
> > doesn't necessarily mean that the maximum should be lower, no?
>
> > Do you have some specific modifications of my code in mind regarding
> > this?
>
> I would expect that if you have two separate register maps they would
> have separate configurations that describe the corresponding physical
> register maps, as far as I can tell this driver is just making up a
> maximum register number.

Alright, so I should just use a separate config for each regmap and set
the max_register value for each to whatever I can find is actually the
highest used value in the downstream code -- correct?

Thank you,
K. B.