Re: [PATCH 3/3] dt-bindings: iio: accel: bma255: Merge bosch,bma180 schema

[Stephan Gerhold <stephan@gerhold.net>]

On Wed, Jun 16, 2021 at 11:04:36AM +0200, Linus Walleij wrote:
> On Mon, Jun 14, 2021 at 6:34 PM Stephan Gerhold <stephan@gerhold.net> wrote:
> 
> > In Linux the bma180 and bmc150-accel driver cover fairly similar chips
> > from Bosch (just with minor register differences). For the DT schema,
> > this does not make any difference: They both represent I2C/SPI devices,
> > have one or two interrupts plus a vdd/vddio-supply.
> >
> > This means there is no need to duplicate the schema, we can just
> > document the compatibles for both drivers in a single DT schema.
> >
> > Suggested-by: Jonathan Cameron <jic23@kernel.org>
> > Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> 
> > Some additional notes:
> >   - The datasheet links in bma180 sadly seem all broken for me so
> >     I just dropped them.
> 
> Fair enough, but some people would be able to obtain them using the
> Wayback machine.
>

Good point, perhaps we should add some links directly to the Wayback
Machine if it still has some of the datasheets. Those links should be
more stable. :)
 
> >   - I separated the bma180/bmc150-accel compatibles using a comment.
> >     This is just for clarity, it has no influence on the schema.
> 
> Some DT binding maintainers may be allergic to any mention of
> Linux particulars in binding documents but I am not so fine by me.
> 

Yeah, I kind of expected this to be honest. I don't mind removing those
comments, just thought it would be a bit less confusing for people who
read the bindings (so they know which driver covers which compatibles).
And for those using the bindings outside Linux, the comments can just be
ignored since they do not have any semantic meaning.

> 
> > In the future we could consider combining even more schemas.
> > In particular bosch,bma400.yaml and bosch,bmi088.yaml are also
> > almost identical, although they currently specify different interrupt
> > types. I think in general the situation for those Bosch sensors is
> > exactly the same: The sensors can be configured to either active-high
> > or active-low level. However, at the moment neither bma400 or bmi088
> > actually implement interrupt support. For now I kept those schemas
> > as-is, I think this is better left up for follow-up patches.
> 
> The situation is caused by Bosch sensortec
> division not being particularly involved with the maintenance of these
> drivers in the Linux kernel. (They did send a few initial patches
> some years back, but since have not been heard from.)
> 
> It would be great to get the attention of someone in charge
> @bosch-sensortec.com.
> 
> Their own drivers seem to target stuff like Arduino but more
> generally on the "OS independence shim"-paradigm:
> https://github.com/BoschSensortec
> 
> They have their own community here:
> https://community.bosch-sensortec.com/t5/Bosch-Sensortec-Community/ct-p/bst_community
> Their users ask questions about Linux sensor support all the time.
> Their stance seem to be to work directly with companies making
> products through FAE:s (field application engineers). It's a bit
> like a guild.
> 
> I tried to find a real mail address to them but failed.
> 

Yeah it would be nice if they would become a bit more involved. But from
my experience with various other vendors I'm not really expecting much
here sadly. However, I would be very happy to be proven otherwise. :)

Thanks!
Stephan