[RFC v2 00/11] iio: add iio backend device type

[Olivier Moysan]

This v2 is an addon to initial RFC:
https://lore.kernel.org/lkml/20230623140944.2613002-1-olivier.moysan@foss.st.com/

Despite the "IIO backend" naming has to be changed (as pointed out by
Jonathan previously), it has been kept here, for time being. The
appropriated naming still has to be discussed later on.

In the previous RFC the "IIO backend" concept was proposed through
a set of template APIs.

This v2 implements a functionnal exemple based on STM32 DFSDM,
to bring scaling support to this peripheral.

Olivier Moysan (11):
  iio: introduce iio backend device
  of: property: add device link support for io-backends
  dt-bindings: iio: stm32-dfsdm-adc: add scaling support
  dt-bindings: iio: adc: add scaling support to sd modulator
  iio: adc: stm32-dfsdm: manage dfsdm as a channel provider
  iio: adc: stm32-dfsdm: adopt generic channel bindings
  iio: adc: stm32-dfsdm: add scaling support to dfsdm
  iio: adc: sd modulator: add scale and offset support
  ARM: dts: stm32: adopt new dfsdm bindings on stm32mp151
  ARM: dts: stm32: add dfsdm pins muxing on stm32mp15
  ARM: dts: stm32: add dfsdm iio support on stm32mp157c-ev

 .../iio/adc/sigma-delta-modulator.yaml        |   9 +-
 .../bindings/iio/adc/st,stm32-dfsdm-adc.yaml  | 189 ++++++------------
 arch/arm/boot/dts/st/stm32mp15-pinctrl.dtsi   |  39 ++++
 arch/arm/boot/dts/st/stm32mp151.dtsi          |  18 +-
 arch/arm/boot/dts/st/stm32mp157c-ev1.dts      |  68 +++++++
 drivers/iio/Makefile                          |   1 +
 drivers/iio/adc/sd_adc_modulator.c            | 106 ++++++++--
 drivers/iio/adc/stm32-dfsdm-adc.c             | 187 +++++++++++------
 drivers/iio/industrialio-backend.c            | 107 ++++++++++
 drivers/of/property.c                         |   2 +
 include/linux/iio/backend.h                   |  56 ++++++
 11 files changed, 561 insertions(+), 221 deletions(-)
 create mode 100644 drivers/iio/industrialio-backend.c
 create mode 100644 include/linux/iio/backend.h

-- 
2.25.1