On Thu, 5 Sep 2024 14:14:37 -0500 David Lechner <dlechner@xxxxxxxxxxxx> wrote: > On 9/5/24 10:17 AM, Angelo Dureghello wrote: > > From: Angelo Dureghello <adureghello@xxxxxxxxxxxx> > > > > Some DACs as ad3552r need a synchronous mode setting, adding > > this parameter for ad3552r and for future use on other DACs, > > if needed. > > > > Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx> > > --- > > Documentation/ABI/testing/sysfs-bus-iio-dac | 16 ++++++++++++++++ > > 1 file changed, 16 insertions(+) > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio-dac b/Documentation/ABI/testing/sysfs-bus-iio-dac > > index 810eaac5533c..2f4960c79385 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-iio-dac > > +++ b/Documentation/ABI/testing/sysfs-bus-iio-dac > > @@ -59,3 +59,19 @@ Description: > > multiple predefined symbols. Each symbol corresponds to a different > > output, denoted as out_voltageY_rawN, where N is the integer value > > of the symbol. Writing an integer value N will select out_voltageY_rawN. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/out_voltage_synchronous_mode > > +KernelVersion: 6.13 > > +Contact: linux-iio@xxxxxxxxxxxxxxx > > +Description: > > + Arm or disarm a wait-for-synchronization flag. Arming this flag > > + means the DAC will wait for a synchronizatiopn signal on a > > + specific internal or external wired connection. I.e., there are > > + cases where multiple DACs IP are built in the same chip or fpga > > + design, and they need to start the data stream synchronized. > > + > > +What: /sys/bus/iio/devices/iio:deviceX/out_voltage_synchronous_mode_available > > +KernelVersion: 6.13 > > +Contact: linux-iio@xxxxxxxxxxxxxxx > > +Description: > > + List of available values for synchronous_mode. > > > > Since this depends on how things are wired, it seems like this should be > something specified in the devicetree, not through sysfs attributes. > Agreed. Smells like a wiring thing given the description. Is there a case where it works either way and it is usecase dependent which choice makes sense? Superficially it seems likely if a board has this wired, there is little disadvantage in using it always. Jonathan >
