[RFC PATCH 0/8] iio: dac: introducing ad3552r-axi

[Angelo Dureghello]

Hi, asking for comments for this patchset, that is mostly 
ready, at least feature-complete and functionally tested.

I am introducing ad3552r-axi variant, controlled from a fpga-based
AXI IP, as a platform driver, using the DAC backend. The patchset is
actually based on linux-iio, since some needed DAC backend features
was already there on that repo only, still to be merged in mainline.

Comments i would like to ask are:

- i added some devicetree bindings inside current ad3552r yaml,
  device is the same, so i wouldn't create a different yaml file.  

- if it's ok adding the bus-type property in the DAC backend:
  actually, this platform driver uses a 4 lanes parallel bus, plus
  a clock line, similar to a qspi. This to read an write registers
  and as well to send samples at double data rate. Other DAC may 
  need "parallel" or "lvds" in the future.

- adding the bus-type property vs. a boolean property vs. adding 
  a new compatible string.

- how external synchronization should be handled. Actually, i added
  2 backend calls to enable or disable this external trigger.

- is a read-only sampling-frequency useful ?

Thanks a lot for your feedbacks.

To: Lars-Peter Clausen <lars@xxxxxxxxxx>
To: Michael Hennerich <Michael.Hennerich@xxxxxxxxxx>
To: Nuno Sá <nuno.sa@xxxxxxxxxx>
To: Jonathan Cameron <jic23@xxxxxxxxxx>
To: Rob Herring <robh@xxxxxxxxxx>
To: Krzysztof Kozlowski <krzk+dt@xxxxxxxxxx>
To: Conor Dooley <conor+dt@xxxxxxxxxx>
To: Olivier Moysan <olivier.moysan@xxxxxxxxxxx>
Cc: linux-iio@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: dlechner@xxxxxxxxxxxx

Signed-off-by: Angelo Dureghello <adureghello@xxxxxxxxxxxx>
---
Angelo Dureghello (8):
      dt-bindings: iio: dac: ad3552r: add io-backend property
      iio: backend: extend features
      iio: backend adi-axi-dac: backend features
      dt-bindings: iio: dac: add adi axi-dac bus property
      iio: dac: ad3552r: changes to use FIELD_PREP
      iio: dac: ad3552r: extract common code (no changes in behavior intended)
      iio: dac: ad3552r: add axi platform driver
      iio: ABI: add DAC sysfs synchronous_mode parameter

 Documentation/ABI/testing/sysfs-bus-iio-dac        |   7 +
 .../devicetree/bindings/iio/dac/adi,ad3552r.yaml   |  39 +-
 .../devicetree/bindings/iio/dac/adi,axi-dac.yaml   |   9 +
 drivers/iio/dac/Kconfig                            |  11 +
 drivers/iio/dac/Makefile                           |   3 +-
 drivers/iio/dac/ad3552r-axi.c                      | 572 +++++++++++++++++++++
 drivers/iio/dac/ad3552r-common.c                   | 163 ++++++
 drivers/iio/dac/ad3552r.c                          | 394 +++-----------
 drivers/iio/dac/ad3552r.h                          | 199 +++++++
 drivers/iio/dac/adi-axi-dac.c                      | 250 ++++++++-
 drivers/iio/industrialio-backend.c                 | 151 ++++++
 include/linux/iio/backend.h                        |  24 +
 12 files changed, 1494 insertions(+), 328 deletions(-)
---
base-commit: 7ccb2c2db44572deadb795c4637273cdabbe8b66
change-id: 20240829-wip-bl-ad3552r-axi-v0-b1e379c986d3

Best regards,
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