Re: QEMU question: upstreaming I2C device with unpublished datasheet

[Corey Minyard]

On Tue, Jul 27, 2021 at 10:23:26AM +0100, Peter Maydell wrote:
> On Wed, 21 Jul 2021 at 22:06, Shengtan Mao <stmao@google.com> wrote:
> >
> > Hi everyone,
> > we are hoping to upstream a MAX I2C device to QEMU. The device's datasheet 
> > is not public, and we are contacting the Maxim company to get their 
> > permission. If Maxim is okay with upstreaming the device with an 
> > unpublished datasheet, will this still be an issue with QEMU?
> 
> It's not inherently a blocker, but the difficulty is code review.
> Without knowing how the device should behave, it's hard to tell
> whether the model is doing the right thing. Ideally Maxim should
> just publish their datasheet, so if you/your company has any
> leverage with them you should push them to do that :-)
> 
> That said, we do have other device models in the tree which
> don't have public datasheets, and as long as the device is not
> too complicated we should be OK as long as you can also submit
> enough test cases that we could refactor the device in future
> without worrying too much that we're breaking it because we don't
> know how it's supposed to behave.

Thanks Peter.

I will add that you need to be sure you have the legal right to publish
the software.  If you have a non-public datasheet, that probably means
you had to sign NDA or something like that to see it.  That may limit
what you can do.

-corey