staging:iio: Remove periodic RTC trigger driver

With the recently introduced hrtimer based trigger we have a fully
functional replacement for the RTC timer trigger that is more flexible and
has a better interface to instantiate and manage the trigger instances. The
RTC trigger timer could only be instantiated using platform devices which
makes it unsuitable for modern devicetree based platforms, while the
hrtimer trigger has a configfs based interface that allows creating and
deletion of triggers at runtime.

In addition since a few years the periodic RTC timer is internally always
emulated using a hrtimer using the hrtimer interface directly will yield
the same timing precision. So using the RTC timer won't have any advantages
on this front either.

There is also no evidence that the periodic RTC trigger is currently
actually being used on any system. So considering all this remove the
driver. Also remove the related item from the TODO list.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Daniel Baluta <daniel.baluta@intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 0 insertions, 8 deletions

diff --git a/drivers/staging/iio/TODO b/drivers/staging/iio/TODO
index c22a0edd1528..93a896883e37 100644
--- a/drivers/staging/iio/TODO
+++ b/drivers/staging/iio/TODO
@@ -58,14 +58,6 @@ different requirements.  This one suits mid range
 frequencies (100Hz - 4kHz).
 2) Lots of testing
 
-Periodic Timer trigger
-1) Move to a more general hardware periodic timer request
-subsystem. Current approach is abusing purpose of RTC.
-Initial discussions have taken place, but no actual code
-is in place as yet. This topic will be reopened on lkml
-shortly. I don't really envision this patch being merged
-in anything like its current form.
-
 GPIO trigger
 1) Add control over the type of interrupt etc.  This will
 necessitate a header that is also visible from arch board