diff mbox series

[v4,2/3] dt-bindings: auxdisplay: Add bindings for generic 7-segment LED

Message ID 20240305035853.916430-3-chris.packham@alliedtelesis.co.nz
State Changes Requested, archived
Headers show
Series auxdisplay: 7-segment LED display | expand

Checks

Context Check Description
robh/checkpatch success
robh/patch-applied success
robh/dtbs-check warning build log
robh/dt-meta-schema success

Commit Message

Chris Packham March 5, 2024, 3:58 a.m. UTC 
Add bindings for a generic 7-segment LED display using GPIOs.

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

Notes:
    Changes in v4:
    - Add ASCII art diagram showing arrangement of segments
    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   | 54 +++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml

Comments

Geert Uytterhoeven March 5, 2024, 8:19 a.m. UTC | #1 
Hi Chris,

On Tue, Mar 5, 2024 at 4:59 AM Chris Packham
<chris.packham@alliedtelesis.co.nz> wrote:
> Add bindings for a generic 7-segment LED display using GPIOs.
>
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
>
> Notes:
>     Changes in v4:
>     - Add ASCII art diagram showing arrangement of segments

Thanks for the update!

> --- /dev/null
> +++ b/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml
> @@ -0,0 +1,54 @@
> +# 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:

Please add "|", as you want to preserve the formatting of the diagram.

> +      An array of GPIOs one per segment. The first GPIO corresponds to the A
> +      segment the last GPIO corresponds to the G segment. Some LED blocks also

... segment, the ...


> +      have a decimal point (currently ignored).
> +
> +               -a-
> +              |   |
> +              f   b
> +              |   |
> +               -g-
> +              |   |
> +              e   c
> +              |   |
> +               -d-  dp
> +
> +    minItems: 7
> +    maxItems: 7

I guess it doesn't hurt to have "maxItems: 8", so people don't have
to update their DTS later when support for the DP is added?
That would need an update to the description above, as the last segment
would then be either G or DP.

> +
> +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>;

Please group GPIO specifiers using angular brackets:

    segment-gpios = <&gpio 0 GPIO_ACTIVE_LOW>,
                     <&gpio 1 GPIO_ACTIVE_LOW>,
                     ...

> +    };

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds
diff mbox series

Patch

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..172548dfb142
--- /dev/null
+++ b/Documentation/devicetree/bindings/auxdisplay/gpio-7-segment.yaml
@@ -0,0 +1,54 @@ 
+# 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. Some LED blocks also
+      have a decimal point (currently ignored).
+
+               -a-
+              |   |
+              f   b
+              |   |
+               -g-
+              |   |
+              e   c
+              |   |
+               -d-  dp
+
+    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>;
+    };