Re: [PATCH v3 2/5] dt-bindings: auxdisplay: Add Titan Micro Electronics TM1628

[Heiner Kallweit <hkallweit1@xxxxxxxxx>]

On 24.02.2022 21:22, Rob Herring wrote:
> On Wed, Feb 23, 2022 at 06:59:31PM +0100, Heiner Kallweit wrote:
>> Add a YAML schema binding for TM1628 auxdisplay
>> (7/11-segment LED) controller.
>>
>> This patch is partially based on previous work from
>> Andreas Färber <afaerber@xxxxxxx>.
>>
>> Co-Developed-by: Andreas Färber <afaerber@xxxxxxx>
>> Signed-off-by: Andreas Färber <afaerber@xxxxxxx>
>> Co-Developed-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> ---
>> v3:
>> - fix remaining YAML issues
>> - use Co-Developed-by
>> ---
>>  .../bindings/auxdisplay/titanmec,tm1628.yaml  | 92 +++++++++++++++++++
>>  1 file changed, 92 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml b/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml
>> new file mode 100644
>> index 000000000..2a1ef692c
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/auxdisplay/titanmec,tm1628.yaml
>> @@ -0,0 +1,92 @@
>> +# SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id: http://devicetree.org/schemas/auxdisplay/titanmec,tm1628.yaml#
>> +$schema: http://devicetree.org/meta-schemas/core.yaml#
>> +
>> +title: Titan Micro Electronics TM1628 LED controller
>> +
>> +maintainers:
>> +  - Andreas Färber <afaerber@xxxxxxx>
>> +  - Heiner Kallweit <hkallweit1@xxxxxxxxx>
>> +
>> +allOf:
>> +  - $ref: /schemas/spi/spi-peripheral-props.yaml#
>> +
>> +properties:
>> +  compatible:
>> +    const: titanmec,tm1628
>> +
>> +  reg:
>> +    maxItems: 1
>> +
> 
>> +  grid:
>> +    description:
>> +      Mapping of display digit position to grid number.
>> +      This implicitly defines the display size.
>> +    $ref: /schemas/types.yaml#/definitions/uint8-array
>> +    minItems: 1
>> +    maxItems: 7
>> +
>> +  segment-mapping:
>> +    description:
>> +      Mapping of 7 segment display segments A-G to bit numbers 1-12.
>> +    $ref: /schemas/types.yaml#/definitions/uint8-array
>> +    minItems: 7
>> +    maxItems: 7
> 
> Are these properties useful for any 7 segment display or specific to 
> this controller?
> 
Both are controller-specific. E.g. the functionally similar driver
ht16k33 uses different properties.

> The commit msg mentions 11 segment display. Does this need to be?:
> 
> oneOf:
>   - minItems: 7
>     maxItems: 7
>   - minItems: 11
>     maxItems: 11
> 
The controller would be able to drive 11 segments, but the driver
supports 7 segments only (at least for now). Therefore a 11 segment
display can be used, but only the 7 segment part will be active.
All devices with this controller I've seen and heard of have
7 segment displays.

> 
>> +
>> +  "#address-cells":
>> +    const: 2
>> +
>> +  "#size-cells":
>> +    const: 0
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +
>> +patternProperties:
>> +  "^.*@[1-7],([1-9]|1[0-6])$":
>> +    type: object
>> +    $ref: /schemas/leds/common.yaml#
>> +    unevaluatedProperties: false
>> +    description: |
>> +      Properties for a single LED.
>> +
>> +    properties:
>> +      reg:
>> +        description: |
>> +          1-based grid number, followed by 1-based segment bit number.
>> +        maxItems: 1
>> +
>> +    required:
>> +      - reg
>> +
>> +unevaluatedProperties: false
>> +
>> +examples:
>> +  - |
>> +    #include <dt-bindings/leds/common.h>
>> +
>> +    spi {
>> +        #address-cells = <1>;
>> +        #size-cells = <0>;
>> +
>> +        led-controller@0 {
>> +            compatible = "titanmec,tm1628";
>> +            reg = <0>;
>> +            spi-3-wire;
>> +            spi-lsb-first;
>> +            spi-max-frequency = <500000>;
>> +            grid = /bits/ 8 <4 3 2 1>;
>> +            segment-mapping = /bits/ 8 <4 5 6 1 2 3 7>;
>> +            #address-cells = <2>;
>> +            #size-cells = <0>;
>> +
>> +            alarmn@5,4 {
>> +                reg = <5 4>;
>> +                function = LED_FUNCTION_ALARM;
>> +            };
>> +        };
>> +    };
>> +...
>> -- 
>> 2.35.1
>>
>>
>>