On 11/24/21 2:50 PM, Andreas Kemnade wrote:

On Wed, 24 Nov 2021 12:09:44 -0800
Guenter Roeck [off-list ref] wrote:

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On 11/24/21 11:35 AM, Andreas Kemnade wrote:

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Hi,

On Tue, 23 Nov 2021 07:39:05 -0800
Guenter Roeck [off-list ref] wrote:
   

quoted

On 11/23/21 4:14 AM, Alistair Francis wrote:

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On Tue, Nov 16, 2021 at 9:10 AM Andreas Kemnade [off-list ref] wrote:

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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.

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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

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