Re: [PATCH 2/2] iio: adc: ad7944: add driver for AD7944/AD7985/AD7986

[Jonathan Cameron <Jonathan.Cameron@Huawei.com>]

On Sun, 11 Feb 2024 11:03:43 -0600
David Lechner <dlechner@baylibre.com> wrote:

> On Sat, Feb 10, 2024 at 11:47 AM Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > On Tue,  6 Feb 2024 11:26:00 -0600
> > David Lechner <dlechner@baylibre.com> wrote:
> >  
> > > This adds a driver for the Analog Devices Inc. AD7944, AD7985, and
> > > AD7986 ADCs. These are a family of pin-compatible ADCs that can sample
> > > at rates up to 2.5 MSPS.
> > >
> > > The initial driver adds support for sampling at lower rates using the
> > > usual IIO triggered buffer and can handle all 3 possible reference
> > > voltage configurations.
> > >
> > > Signed-off-by: David Lechner <dlechner@baylibre.com>  
> >
> >
> > The one thing in here that will probably bite if this gets much use of
> > different boards is the use of non multiple of 8 word sizes.
> >
> > Often we can get away with padding those with trailing clocks.
> > Any idea if that is safe here?  
> 
> We can probably get away with it on these chips. The ultimate goal
> here, though, is to get these chips working a max sample rate which
> only has a few 10s of nanoseconds of wiggle room between SPI
> transfers. So I would rather have a bit more play in the timing than
> try to support generic SPI controllers.
> 
Would just be a case of providing a fallback. If you have a good spi
controller then you get better data rats.

Meh, can be added later when someone needs this. We've done that a few
times before.

Jonathan