Re: [PATCH 5/5] dt-bindings: iio: Add adis16475 documentation

Sa, Nuno
2020-03-05T13:04:51Z

On Thu, 2020-03-05 at 13:43 +0100, Lars-Peter Clausen wrote:
> On 3/5/20 1:27 PM, Sa, Nuno wrote:
> > > In my opinion there is should not be a difference in the
> > > userspace
> > > interface for chips that do support 32-bit burst and those that
> > > don't.
> > > For devices that don't support 32-bit burst it should be emulated
> > > by
> > > reading the LSB bits registers manually.
> > Hmm. In terms of interface I think there is no difference. We
> > always
> > report 32bits channels (for accel and gyro). However, what we do
> > right
> > know is just to set the LSB to 0 if burst32 is not supported. So,
> > we
> > can be just ignoring the LSB bits if they are being used...
>
> What I meant was that somebody might still want to get the full 32-
> bit
> values in buffered mode, even if the device does not support burst32.

They are. Just that the LSB part is always set to 0 :). And that, in my
opinion, is wrong. As you say, we should do the manual readings if
there are any bits on the LSB registers...

- Nuno Sá
> In
> that case you can first do a 16-bit burst read to get the MSBs and
> then
> do manual reads of all the LSB registers and then put both into the
> buffer.
> - Lars
>