[PATCH v4 0/2] iio: dac: Add support for MAX22007 DAC

[Janani Sunil <janani.sunil@analog.com>]

This patch series introduces support for the Analog Devices MAX22007, a
quad-channel, 12-bit digital-to-analog converter (DAC) with integrated
precision output amplifiers and configurable voltage/current output capability.

**Device Overview:**
The MAX22007 features four independent DAC channels that can each be configured
for either voltage output (0-12.5V) or current output (0-25mA) mode. The device
communicates via SPI interface with built-in CRC8 error checking for data integrity.

**Features Implemented:**
- Support for all 4 DAC channels with 12-bit resolution
- Per-channel voltage/current mode configuration via device tree
  property `adi,ch-func = [voltage, current]`
- Independent power control for each channel (attribute)
- Hardware reset support via GPIO (during probe)
- CRC8 error checking for SPI communication

**Patch Summary:**
1. dt-bindings: Binding documentation with channel configuration
2. driver: Implement IIO DAC driver

**Testing:**
The driver was hardware tested on a Raspberry Pi4 on top of v6.12.y
kernel using the MAX22007EVKIT evaluation board.

Janani Sunil (3):

dt-bindings: iio: dac: Add max22007
iio: dac: Add MAX22007 DAC driver support
---
To: Lars-Peter Clausen <lars@metafoo.de>
To: Michael Hennerich <Michael.Hennerich@analog.com>
To: Jonathan Cameron <jic23@kernel.org>
To: Rob Herring <robh@kernel.org>
To: Krzysztof Kozlowski <krzk+dt@kernel.org>
To: Conor Dooley <conor+dt@kernel.org>
To: Jonathan Corbet <corbet@lwn.net>
Cc: linux-iio@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: jan.sun97@gmail.com
Cc: gastmaier@gmail.com
Signed-off-by: Janani Sunil <janani.sunil@analog.com>

---
Changes in v4:
- Re-sent of improper v3 (at v3 I *accidentaly* reverted the dt-binding
  commit to v1 after a rebase).
- Corrected description for reset GPIO in the dt-binding
- Wrap commit description at 75 columns
- Link to v3: https://lore.kernel.org/r/20260114-max22007-patch-v3-0-769298f50b8a@analog.com

Changes in v3:
- Remove node defined for power supplies in the devicetree documentaiton
- Made use of CRC8_TABLE_SIZE macro in the crc table definition
- Corrected casting of reg address in the SPI read function
- Applied reverse christmas tree variable ordering
- Added a macro fro the reference voltage and reused the same in the
  scale factor
- Removed usage of 'supplies' in enabling bulk regulator and removed
  unused variable 'i'
- Added step n the probe function to toggle the reset GPIO
- Updated spacing in macro definitions
- Link to v2: https://lore.kernel.org/r/20260108-max22007-dev-v2-0-2506c738784f@analog.com/

Changes in v2:
- Wrap commit messages as per coding guidelines
- Removed all driver references from the hardware
- Update property description for reset-gpio
- Removed allOf
- Added minimum/maximum limits for channel number in the devicetree
  binding
- Replaced adi,type with adi,ch-func.
- Added reference to required supplies in the binding, configured them
  in the driver
- Channels are not a required property anymore.
- Replaced instances of 'channel' in macros to just 'ch'
- Added trailing commas wherever necessary, removed them as per comments
- Add explicit values for enum- max22007_channel_power
- Replace channel spec structure member 'iio_chan' with 'iio_chans'
- Use spi_write_then_read() API in the max22007_spi_read() API
- Check for reg_size ==1 and hardcode the size otherwise
- Wrap lines in the driver to 80 characters
- Update in-line comment on the resolution
- Separate declarations with assignment, from the ones that don't
- Update the usage of channel template
- Add a local device descriptor to point to the SPI device
- Add a transition of the Reset GPIO from low to high in the probe
- Make use of regmap_set_bits() instead of regmap_update_bits during CRC
  Enable function call.
- Remove the documentation commit, as it is not needed anymore.
- Link to v1: https://lore.kernel.org/r/20251219-max22007-dev-v1-0-242da2c2b868@analog.com

---
Janani Sunil (2):
      dt-bindings: iio: dac: Add max22007
      iio: dac: Add MAX22007 DAC driver support

 .../devicetree/bindings/iio/dac/adi,max22007.yaml  | 120 +++++
 MAINTAINERS                                        |   8 +
 drivers/iio/dac/Kconfig                            |  13 +
 drivers/iio/dac/Makefile                           |   1 +
 drivers/iio/dac/max22007.c                         | 488 +++++++++++++++++++++
 5 files changed, 630 insertions(+)
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20260114-max22007-patch-6b5c48e37457

Best regards,
-- 
Janani Sunil <janani.sunil@analog.com>