On Sun, 7 Mar 2021 10:40:18 +0100 Lars-Peter Clausen <lars@xxxxxxxxxx> wrote: > On 1/17/21 4:38 PM, Jonathan Cameron wrote: > > From: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > > > > The timer-stm32 provided a little more specific information than the main > > docs about the value of 0 corresponding to stopping sampling. Given that > > this makes sense in general, move that statement over to the main docs > > and drop the version in sysfs-bus-iio-timer-stm32 > > > > Fixes > > $ scripts/get_abi.pl validate > > /sys/bus/iio/devices/triggerX/sampling_frequency is defined 2 times: ./Documentation/ABI/testing/sysfs-bus-iio-timer-stm32:92 ./Documentation/ABI/testing/sysfs-bus-iio:45 > > > > Cc: Fabrice Gasnier <fabrice.gasnier@xxxxxx> > > Reported-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx> > > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> > > --- > > Documentation/ABI/testing/sysfs-bus-iio | 2 ++ > > Documentation/ABI/testing/sysfs-bus-iio-timer-stm32 | 8 -------- > > 2 files changed, 2 insertions(+), 8 deletions(-) > > > > diff --git a/Documentation/ABI/testing/sysfs-bus-iio b/Documentation/ABI/testing/sysfs-bus-iio > > index d2dd9cc280f9..9b5ceb22363d 100644 > > --- a/Documentation/ABI/testing/sysfs-bus-iio > > +++ b/Documentation/ABI/testing/sysfs-bus-iio > > @@ -55,6 +55,8 @@ Description: > > direct access interfaces, it may be found in any of the > > relevant directories. If it affects all of the above > > then it is to be found in the base device directory. > > + Note a value 0 where supported, will correspond to sampling > > + stopping. > > Hm, I don't like this. 0 should be an invalid value for the standard > ABI. Enabling/disabling of the trigger should be controlled by whether > there are any active trigger consumers. > > The stm32-timer-trigger implements a non-standard ABI and I think we > need to document this explicitly. The driver does not have a set_state > callback. So the frequency property is used to enable/disable the > trigger, but as said above, for standard compliant triggers that should > not be the case. > Good point. Ideally we'd also fix the stm32-timer-trigger to have an explicit enable / disable (even if that works by setting the frequency to 0 under the hook) For now I've dropped the patch until this is resolved. Thanks, Jonathan