Add backend support for getting the data source used.
The ad3552r HDL implements an internal ramp generator, so adding the
getter to allow data source get/set by debugfs.
Reviewed-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Angelo Dureghello <adureghello@baylibre.com>
Link: https://patch.msgid.link/20250409-wip-bl-ad3552r-fixes-v5-3-fb429c3a6515@baylibre.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
2086321576