Re: [PATCH v2 3/3] iio: flow: add Sensirion SLF3S liquid flow sensor driver

From: Jonathan Cameron

Date: Sun May 31 2026 - 04:52:48 EST


>
> Will go through the includes and add the missing ones for what is
> used directly.

General hint on process. Don't bother saying yes. Just delete
those bits when replying so we can focus on the more interesting
stuff: questions etc.

>
> > More than likely we need some level of sleep here for the device to
> > wake up. Is there anything in the datasheet?
>
> Yes, tPU = 25 ms max (time to sensor ready). Will add
> fsleep(25000) after the regulator enable. Also tw = 60 ms typ
> (warm-up until output within spec), so will bump the existing
> SLF3S_MEAS_START_DELAY_US from 12 ms to 60 ms.

> > Sashiko (probably correctly) identifies that the formatting that the
> > IIO core does for an IIO_VAL_FRACTIONAL only goes to 9 decimal places.
> > [...] maybe switch to using IIO_VAL_DECIMAL64_PICO
> > +CC Rodrigo
>
> Confirmed, the SLF3S-0600F scale (~1.67e-9 l/s/LSB) gets
> truncated to 1 digit, the 1300F loses some precision too.
>
> I would prefer waiting for Rodrigo's IIO_VAL_DECIMAL64_PICO over
> bumping the FRACTIONAL formatter, since pico covers all variants
> and avoids changing core behaviour for everyone. Plan would be
> to send v3 with all other points addressed and respin to v4 once
> PICO is in mainline. Ok with you, or would you rather see the
> FRACTIONAL bump now?

PICO path seems the easier one, base on top of Rodrigo's series
and add a note about the dependency. I have no idea what
Sashiko will do with a list of dependent patches, so we may
get some spurious suggestions that the code won't build etc
like we currently get for scan_type.format


Jonathan


>
> Thanks again,
> Wadim