Re: [PATCH v2 0/4] Add QST QMC5883P magnetometer driver

[Andy Shevchenko]

On Sun, Apr 12, 2026 at 10:27:36AM +0000, Hardik Phalet wrote:
> On Fri Apr 10, 2026 at 10:06 AM IST, Andy Shevchenko wrote:
> > On Thu, Apr 09, 2026 at 09:07:11PM +0000, Hardik Phalet wrote:

...

> > - the investigation is rather poor about existence of the driver — make sure
> > there is no compatible (by register layout) driver in IIO or even outside it
> > (for ADCs it might appear as HWMON [drivers/hwmon] or INPUT [drivers/input]
> >  in some cases)
> I will dig a bit deeper into this. But I could not find any thing
> realted to the device I am working on (qmc5883p). 

It might be that there is a driver with smaller amount of registers available
(or bigger) or some features missing...

> There is a device hmc5843_core.c that already handles HMC5883L. But the
> register layout is different, field ranges, gain encoding etc. are
> different and I think warrants a separate driver. Other than that I
> could not find something related to device I am working on. 

This paragraph is a particular case, something like this should be put in the
summary in your case if the brand new driver is needed.

> I will carefully go through HWMON and INPUT too, but do you have a
> strategy to help me find somehting similar? It will be very useful.
> Would `grep`-ing for 5883 and QST be a right starting point?

Grep for words that are case insensitive values of the registers offsets.
This can be done recursively, then you need to apply some heuristics on
the definition names to see if they are about the same thing (or similar)
or not at all.

-- 
With Best Regards,
Andy Shevchenko