This series adds support for testing the digital interface on ad9467 using different test patterns/modes. For doing it, debugFS support for backends is also added. Notably: * backend direct reg access which is not directly needed for the ad9467 new interface but it's something useful to have (the same as IIO direct_reg_access for "normal" IIO devices) and something that I would eventually try to add anyways. * printing channel status which is useful for more verbose information about some possible failure in the test pattern. The first couple of patches are unrelated but simple enough that I placed them in this patchset. --- Nuno Sa (9): iio: backend: remove unused parameter iio: backend: print message in case op is not implemented iio: backend: add debugFs interface iio: backend: add a modified prbs23 support iio: adc: adi-axi-adc: support modified prbs23 iio: adc: adi-axi-adc: split axi_adc_chan_status() iio: adc: adi-axi-adc: implement backend debugfs interface iio: adc: ad9467: add backend test mode helpers iio: adc: ad9467: add digital interface test to debugfs drivers/iio/adc/ad9467.c | 255 +++++++++++++++++++++++++++++++++---- drivers/iio/adc/adi-axi-adc.c | 64 +++++++++- drivers/iio/dac/ad9739a.c | 3 +- drivers/iio/industrialio-backend.c | 123 +++++++++++++++++- include/linux/iio/backend.h | 21 ++- 5 files changed, 428 insertions(+), 38 deletions(-) --- base-commit: 986da024b99a72e64f6bdb3f3f0e52af024b1f50 change-id: 20240709-dev-iio-backend-add-debugfs-ef7cd2007073 -- Thanks! - Nuno Sá