On Mon, 27 Apr 2026 15:54:14 +0100 Rodrigo Alencar <[email protected]> wrote:
> On 26/04/27 11:31AM, Nuno Sá wrote: > > On Mon, Apr 27, 2026 at 10:46:08AM +0100, Jonathan Cameron wrote: > > > On Sun, 26 Apr 2026 21:42:15 +0100 > > > Rodrigo Alencar <[email protected]> wrote: > > > > > > > On 26/04/26 02:10PM, Jonathan Cameron wrote: > > > > > On Fri, 17 Apr 2026 09:17:38 +0100 > > > > > Rodrigo Alencar via B4 Relay > > > > > <[email protected]> wrote: > > > > > > > > > > > From: Rodrigo Alencar <[email protected]> > > > > > > > > > > > > Add documentation for the AD9910 DDS IIO driver, which describes > > > > > > channels, > > > > > > DDS modes, attributes and ABI usage examples. > > > > > > > > > > > > Signed-off-by: Rodrigo Alencar <[email protected]> > > > > > > > > > > Hi Rodrigo, > > > > > > > > > > I think this is getting close to something workable subject to some > > > > > tweaks > > > > > to not make the priority thing visible and use rate of change > > > > > parameters > > > > > so /Sec rather than steps. > > > > > > > > I am not sure about this one. Getting the value into units per seconds > > > > will > > > > increase the range of values by a lot, e.g., for the frequency case the > > > > step > > > > size can range from a few Hz up to the entire supported range (hundreds > > > > of > > > > MHz), and if you consider that one would often have the > > > > sampling_frequency > > > > at 250 MHz... an attribute frequency_roc could have an order of 10^17 > > > > Hz/s, > > > > and I am not sure how practical is that, although it can have a > > > > physical meaning, > > > > like a "chirp slope". > > > > > > That scaling is indeed a bit of a pain though it will go in a 64 bit int > > > however, seems likely we'll get higher frequency devices one day that will > > > limb even faster. > > > > > > Maybe wait and see if anyone else has input on this. > > > > If we think things like RF DACs (which internally - typically - make use > > of things like DDS), we can already go to the GHz "world". > > > > Not saying we already have such a device that would map the new ABI with > > bigger values (we might have but nothing I'm aware of from the top of my > > head) but just saying the above is, indeed, very likely to pop up at some > > time. > > > > Just something to bear in mind :) > > > > - Nuno Sá > > under this Documentation/ABI/testing/sysfs-bus-iio-impedance-analyzer-ad5933, > there is ABI: > /sys/bus/iio/devices/iio:deviceX/out_altvoltageY_frequency_increment > > which seems to be a similar concept to the step used here. Yeah but staging driver so let's not focus on that too much. >
