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

[Guenter Roeck]

On 11/24/21 2:50 PM, Andreas Kemnade wrote:
> On Wed, 24 Nov 2021 12:09:44 -0800
> Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> > 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.
> ok, did so.
>
> > > > 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.
>
> well things seems to match with things I got from analysing the kobo
> sources. So at least the thing in the Kobo Libra H2O seems to be that
> one described in the datasheet, so we can have one sy7636a driver for
> it.
>
> BTW: If I search for a sy7636 on aliexpress I get some SO-8 lithium
> charger ICs.

The datasheet says "PMIC for Electronic Paper Display".

Guenter