[v4,0/2] Add maxim max34408/34409 ADC driver and yaml

Add Maxim max34408/34409 ADC driver and yaml for it. Until now it
supports only current monitioring function without overcurrent
threshold/delay, shutdown delay configuration, alert interrupt.

Changes from v1:
   - minor changes from Rob's comments for yaml
   - add ena, shtdn and make 4 inputs for R sense from Jonathan's comments for yaml
   - add _REG suffix and make prefix for bitmasks and statuses
   - add SCALE/OFFSET instead of AVG/PROCESSED from Jonathan and
     Lars-Peter comments
   - add chip data from Jonathan and Lars-Peter comments
   - minor changes from Lars-Peter and Jonathan comments for driver

Changes from v2:
   - add channels into hardware description into yaml
   - add rsense property per channel
   - rename pins for shtdn and ena pins
   - make one array for input_rsense values

Changes from v3:
   - change *_34408_OCT3 and 4 to *_34409_OCT3 and 4
   - change of_property_read_u32 to fwnode family calls
   - add i2c dev table
   - change of_match_device to i2c_of_match_device
   - change match->data to i2c_get_match_data 

Ivan Mikhaylov (2):
  dt-bindings: adc: provide max34408/9 device tree binding document
  iio: adc: Add driver support for MAX34408/9

 .../bindings/iio/adc/maxim,max34408.yaml      | 137 +++++++++
 drivers/iio/adc/Kconfig                       |  11 +
 drivers/iio/adc/Makefile                      |   1 +
 drivers/iio/adc/max34408.c                    | 278 ++++++++++++++++++
 4 files changed, 427 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
 create mode 100644 drivers/iio/adc/max34408.c

On 05/10/2023 20:55, Ivan Mikhaylov wrote:
> The hardware binding for i2c current monitoring device with overcurrent
> control.
> 
> Signed-off-by: Ivan Mikhaylov <fr0st61te@gmail.com>
> ---
>  .../bindings/iio/adc/maxim,max34408.yaml      | 137 ++++++++++++++++++
>  1 file changed, 137 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
> 
> diff --git a/Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml b/Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
> new file mode 100644
> index 000000000000..4262bedb4bfa
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/iio/adc/maxim,max34408.yaml
> @@ -0,0 +1,137 @@
> +# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/iio/adc/maxim,max34408.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Two- and four-channel current monitors with overcurrent control
> +
> +maintainers:
> +  - Ivan Mikhaylov <fr0st61te@gmail.com>
> +
> +description: |
> +  The MAX34408/MAX34409 are two- and four-channel current monitors that are
> +  configured and monitored with a standard I2C/SMBus serial interface. Each
> +  unidirectional current sensor offers precision high-side operation with a
> +  low full-scale sense voltage. The devices automatically sequence through
> +  two or four channels and collect the current-sense samples and average them
> +  to reduce the effect of impulse noise. The raw ADC samples are compared to
> +  user-programmable digital thresholds to indicate overcurrent conditions.
> +  Overcurrent conditions trigger a hardware output to provide an immediate
> +  indication to shut down any necessary external circuitry.
> +
> +  Specifications about the devices can be found at:
> +  https://www.analog.com/media/en/technical-documentation/data-sheets/MAX34408-MAX34409.pdf
> +
> +properties:
> +  compatible:
> +    enum:
> +      - maxim,max34408
> +      - maxim,max34409
> +
> +  "#address-cells":
> +    const: 1
> +
> +  "#size-cells":
> +    const: 0
> +
> +  reg:
> +    maxItems: 1
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  shutdown-gpios:
> +    description:
> +      Shutdown Output. Open-drain output. This output transitions to high impedance
> +      when any of the digital comparator thresholds are exceeded as long as the ENA
> +      pin is high.
> +    maxItems: 1
> +
> +  shtdn-enable-gpios:

Are these both GPIOs different than standard powerdown-gpios? I suspect
one is different, but the other should be the same. If both are
different, use different names. shutdown gpios is the same as powerdown
gpios....

> +    description:
> +      SHTDN Enable Input. CMOS digital input. Connect to GND to clear the latch and
> +      unconditionally deassert (force low) the SHTDN output and reset the shutdown
> +      delay. Connect to VDD to enable normal latch operation of the SHTDN output.
> +    maxItems: 1
> +
> +  vdd-supply: true
> +
> +required:
> +  - compatible
> +  - reg

required goes after patternProperties.

> +
> +patternProperties:
> +  "^channel@[0-3]$":
> +    $ref: adc.yaml
> +    type: object
> +    description:
> +      Represents the internal channels of the ADC.
> +
> +    properties:
> +      reg:
> +        items:
> +          minimum: 0
> +          maximum: 3
> +
> +      maxim,rsense-val-micro-ohms:
> +        description:
> +          Adjust the Rsense value to monitor higher or lower current levels for
> +          input.
> +        enum: [250, 500, 1000, 5000, 10000, 50000, 100000, 200000, 500000]
> +        default: 1000
> +
> +    required:
> +      - reg
> +      - maxim,rsense-val-micro-ohms
> +
> +    unevaluatedProperties: false
> +
> +allOf:
> +  - if:
> +      properties:
> +        compatible:
> +          contains:
> +            const: maxim,max34408
> +    then:
> +      patternProperties:
> +        "^channel@[2-3]$": false
> +        "^channel@[0-1]$":
> +          properties:
> +            reg:
> +              minimum: 0
> +              maximum: 1
> +    else:
> +      patternProperties:
> +        "^channel@[0-3]$":
> +          properties:
> +            reg:
> +              minimum: 0
> +              maximum: 3
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +

Stray blank line.

> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        adc@1e {
> +              compatible = "maxim,max34409";
> +              reg = <0x1e>;
> +
> +              #address-cells = <1>;
> +              #size-cells = <0>;

Missing blank line


Extend example with GPIOs to make it as complete as reasonable/possible.

Best regards,
Krzysztof