[PATCH v7 0/7] iio: adc: add new ad7380 driver

[Julien Stephan]

Taking over this series with David Lechner's approval, to add some
fixes, proper handling of pseudo differential parts and
some extra commits to add support for 4-channel compatible parts.

Here is David's cover letter:

This series is adding a new driver for the Analog Devices Inc. AD7380,
AD7381, AD7383, and AD7384 ADCs. These chips are part of a family of
simultaneous sampling SAR ADCs.

To keep things simple, the initial driver implementation only supports
the 2/4-channel differential chips listed above. There are also 4-channel
single-ended chips in the family that can be added later.

Furthermore, the driver is just implementing basic support for capturing
data. Additional features like interrupts, CRC, etc. can be added later.

This work is being done by BayLibre and on behalf of Analog Devices Inc.
hence the maintainers are @analog.com.

Changes in v7:
- Removing oversampling support and resolution boost from this series. 
  They will be submitted along with David's series about multiple scan
  types [1], thus removing the RFC tag.

 [1]: https://lore.kernel.org/all/20240524-iio-add-support-for-multiple-scan-types-v2-0-a6c328fdfab7@xxxxxxxxxxxx/

- Link to v6: https://lore.kernel.org/r/20240501-adding-new-ad738x-driver-v6-0-3c0741154728@xxxxxxxxxxxx

Changes in v6:
- Added a comment for math in IIO_CHAN_INFO_OFFSET
- Added a comment for raw buffer
- use iio_device_claim_direct_scoped instead of iio_device_claim_direct_mode

Adding the following commits on top of v5:
- add oversampling support
- add resolution boost support

- Link to v5: https://lore.kernel.org/r/20240319-adding-new-ad738x-driver-v5-0-ce7df004ceb3@xxxxxxxxxxxx

Changes in v5:
- make ad7380_regmap_config static
  Reported-by: kernel test robot <lkp@xxxxxxxxx>
  Closes: https://lore.kernel.org/oe-kbuild-all/202401280629.5kknB57C-lkp@xxxxxxxxx/
- don't use bool in FIELD_PREP
  Reported-by: kernel test robot <lkp@xxxxxxxxx>
  Closes: https://lore.kernel.org/oe-kbuild-all/202401280629.5kknB57C-lkp@xxxxxxxxx/
- fix rx/tx buffer for regmap access
- add datasheet links of supported parts
- move reading reference voltage to probe function
- removed DIFFERENTIAL from a few macro names

Adding the following commits on top of the v4
- add supplies for pseudo-differential chips
- prepare driver to add more compatible parts
- add support for 4-channel compatible parts

- Link to v4: https://lore.kernel.org/all/20240110-ad7380-mainline-v4-0-93a1d96b50fa@xxxxxxxxxxxx

Changes in v4:
- Dropped SPI bindings patch.
- Removed `spi-rx-bus-channels` from the adi,ad7380 bindings.
- Link to v3: https://lore.kernel.org/r/20231215-ad7380-mainline-v3-0-7a11ebf642b9@xxxxxxxxxxxx

Changes in v3:
- dt-bindings:
    - Picked up Conor's Reviewed-By on the adi,ad7380 bindings
- driver:
    - Removed extra indent in DEFINE_AD7380_DIFFERENTIAL_2_CHANNEL macro
    - Removed scan mask that included timestamp channel
    - Removed parent device assignment
    - Picked up Nuno's Reviewed-by
- Link to v2: https://lore.kernel.org/r/20231213-ad7380-mainline-v2-0-cd32150d84a3@xxxxxxxxxxxx

Changes in v2:
- dt-bindings:
    - Added new patch with generic spi-rx-bus-channels property
    - Added maxItems to reg property
    - Replaced adi,sdo-mode property with spi-rx-bus-channels
    - Made spi-rx-bus-channels property optional with default value of 1
      (this made the if: check more complex)
    - Changed example to use gpio for interrupt
- driver:
    - Fixed CONFIG_AD7380 in Makefile
    - rx_buf = st->scan_data.raw instead of rx_buf = &st->scan_data
    - Moved iio_push_to_buffers_with_timestamp() outside of if statement
    - Removed extra blank lines
    - Renamed regulator disable function
    - Dropped checking of adi,sdo-mode property (regardless of the actual
      wiring, we can always use 1-wire mode)
    - Added available_scan_masks
    - Added check for missing driver match data
- Link to v1: https://lore.kernel.org/r/20231208-ad7380-mainline-v1-0-2b33fe2f44ae@xxxxxxxxxxxx

To: Lars-Peter Clausen <lars@xxxxxxxxxx>
To: Michael Hennerich <Michael.Hennerich@xxxxxxxxxx>
To: Nuno Sá <nuno.sa@xxxxxxxxxx>
To: David Lechner <dlechner@xxxxxxxxxxxx>
To: Jonathan Cameron <jic23@xxxxxxxxxx>
To: Rob Herring <robh@xxxxxxxxxx>
To: Krzysztof Kozlowski <krzysztof.kozlowski+dt@xxxxxxxxxx>
To: Conor Dooley <conor+dt@xxxxxxxxxx>
To: Liam Girdwood <lgirdwood@xxxxxxxxx>
To: Mark Brown <broonie@xxxxxxxxxx>
Cc: linux-iio@xxxxxxxxxxxxxxx
Cc: devicetree@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx

Signed-off-by: Julien Stephan <jstephan@xxxxxxxxxxxx>
---
David Lechner (4):
      dt-bindings: iio: adc: Add binding for AD7380 ADCs
      iio: adc: ad7380: new driver for AD7380 ADCs
      dt-bindings: iio: adc: ad7380: add pseudo-differential parts
      iio: adc: ad7380: add support for pseudo-differential parts

Julien Stephan (3):
      iio: adc: ad7380: prepare for parts with more channels
      dt-bindings: iio: adc: ad7380: add support for ad738x-4 4 channels variants
      iio: adc: ad7380: add support for ad738x-4 4 channels variants

 .../devicetree/bindings/iio/adc/adi,ad7380.yaml    | 148 +++++
 MAINTAINERS                                        |  10 +
 drivers/iio/adc/Kconfig                            |  16 +
 drivers/iio/adc/Makefile                           |   1 +
 drivers/iio/adc/ad7380.c                           | 612 +++++++++++++++++++++
 5 files changed, 787 insertions(+)
---
base-commit: 9900e7a54764998ba3a22f06ec629f7b5fe0b422
change-id: 20240311-adding-new-ad738x-driver-5f9b54ad7c74

Best regards,
-- 
Julien Stephan <jstephan@xxxxxxxxxxxx>