Re: [PATCH v15 3/8] mfd: simple-mfd-i2c: Enable support for the silergy,sy7636a

[Guenter Roeck]

On 11/24/21 11:35 AM, Andreas Kemnade wrote:
> Hi,
>
> On Tue, 23 Nov 2021 07:39:05 -0800
> Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> > On 11/23/21 4:14 AM, Alistair Francis wrote:
> > > On Tue, Nov 16, 2021 at 9:10 AM Andreas Kemnade <andreas@xxxxxxxxxxxx> wrote:
> > > > Hi,
> > > >
> > > > this all creates a lot of question marks...
> > > > One of my main question is whether sy7636a = sy7636 (at least the
> > > > driver in the kobo vendor kernels does not have the "A" at the end,
> > > > whic does not necessarily mean a difference).
> > > >
> > > > https://www.silergy.com/products/panel_pmic
> > > > lists only a SY7636ARMC, so chances are good that the letters were just
> > > > stripped away by the driver developers. Printing on chip package is
> > > > cryptic so it is not that helpful. It is just "BWNBDA"
> > >
> > > I don't have a definite answer for you. But I think it's sy7636a
> > >
> > > The page you linked to above lists SY7636ARMC as well as SY7627RMC,
> > > SY7570RMC. That makes me think that the RMC is a generic suffix and
> > > this actual IC is the SY7636A.
> > >    
> >
> > Almost all chips have an ordering suffix, indicating things like
> > temperature range or packaging. The datasheet says:
> yes, they have. The only question is where it starts. So did you find a
> public datasheet which you can chere

I registered an account on the Silergy web site, and I was subsequently
able to download the datasheet. The document has a "confidential"
watermark, so I can not share it. You should be able to register an
account and download it yourself, though.

> > Ordering Information
> > SY7636 □(□□)□
> >               | Temperature Code (C)
> >            | Package Code (RM)
> >          | Optional Spec Code (A)
> >
> > The datasheet otherwise refers to the chip as SY7636A.
> so there is no indication of something like this where the A really
> makes a difference:

I may be missing it, but I see nothing in the datasheet that would indicate
that or if the "A" has any relevance other than "Optional Spec Code",
and I do not see an explanation for that term either.

Guenter