Add bindings for a generic 7-segment LED display using GPIOs.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---

Notes:
    Changes in v3:
    - Set maxItems: 7
    - Expand description of segment-gpios property.
    - Use compatible = "gpio-7-segment" as suggested by Rob
    Changes in v2:
    - Use compatible = "generic-gpio-7seg" to keep checkpatch.pl happy

 .../bindings/auxdisplay/gpio-7-segment.yaml   | 42 +++++++++++++++++++
 1 file changed, 42 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml

diff --git a/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml b/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml
new file mode 100644
index 000000000000..76af4bf4e9a6
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/auxdisplay/gpio-7-segment.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GPIO based LED segment display
+
+maintainers:
+  - Chris Packham <chris.packham@alliedtelesis.co.nz>
+
+properties:
+  compatible:
+    const: gpio-7-segment
+
+  segment-gpios:
+    description:
+      An array of GPIOs one per segment. The first GPIO corresponds to the A
+      segment the last GPIO corresponds to the G segment.
+    minItems: 7
+    maxItems: 7
+
+required:
+  - segment-gpios
+
+additionalProperties: false
+
+examples:
+  - |
+
+    #include <dt-bindings/gpio/gpio.h>
+
+    led-7seg {
+        compatible = "gpio-7-segment";
+        segment-gpios = <&gpio 0 GPIO_ACTIVE_LOW
+                         &gpio 1 GPIO_ACTIVE_LOW
+                         &gpio 2 GPIO_ACTIVE_LOW
+                         &gpio 3 GPIO_ACTIVE_LOW
+                         &gpio 4 GPIO_ACTIVE_LOW
+                         &gpio 5 GPIO_ACTIVE_LOW
+                         &gpio 6 GPIO_ACTIVE_LOW>;
+    };
-- 
2.43.2

On Fri, Mar 01, 2024 at 02:42:01PM +1300, Chris Packham wrote:
> Add bindings for a generic 7-segment LED display using GPIOs.

...

> +  segment-gpios:
> +    description:
> +      An array of GPIOs one per segment. The first GPIO corresponds to the A
> +      segment the last GPIO corresponds to the G segment.
> +    minItems: 7
> +    maxItems: 7

As we discussed, put the ASCII art here to be sure everybody on the same page
what 'a' - 'g' are and I would put 'dp' as well for the better understanding of
the possible configurations (it doesn't mean you have to support it).

...

Either way this will require an Ack by DT maintainers.

-- 
With Best Regards,
Andy Shevchenko