Add binding for Sitronix ST7920 display.

Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
---
 .../bindings/display/sitronix,st7920.yaml          | 55 ++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/Documentation/devicetree/bindings/display/sitronix,st7920.yaml b/Documentation/devicetree/bindings/display/sitronix,st7920.yaml
new file mode 100644
index 0000000000000000000000000000000000000000..caee85f98c6d242dfab73729210f8c34b23a3a99
--- /dev/null
+++ b/Documentation/devicetree/bindings/display/sitronix,st7920.yaml
@@ -0,0 +1,55 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/display/sitronix,st7920.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Sitronix ST7920 LCD Display Controllers
+
+maintainers:
+  - Iker Pedrosa <ikerpedrosam@gmail.com>
+
+description: |
+  The Sitronix ST7920 is a controller for monochrome dot-matrix graphical LCDs,
+  most commonly used for 128x64 pixel displays.
+  This binding supports connecting the display via a standard SPI bus.
+
+properties:
+  compatible:
+    const: sitronix,st7920
+
+  reg:
+    description: The chip-select number for the device on the SPI bus.
+    maxItems: 1
+
+  spi-max-frequency:
+    description: Maximum SPI clock frequency in Hz.
+    maximum: 600000
+
+  spi-cs-high:
+    type: boolean
+    description: Indicates the chip select is active high.
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+
+additionalProperties: false
+
+examples:
+  - |
+    // Example: ST7920 connected to an SPI bus
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi0 {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        display@0 {
+            compatible = "sitronix,st7920";
+            reg = <0>; // Chip select 0
+            spi-max-frequency = <600000>;
+            spi-cs-high;
+        };
+    };

-- 
2.50.1

On 06/08/2025 14:48, Iker Pedrosa wrote:
> +title: Sitronix ST7920 LCD Display Controllers
> +
> +maintainers:
> +  - Iker Pedrosa <ikerpedrosam@gmail.com>
> +
> +description: |

Do not need '|' unless you need to preserve formatting.

> +  The Sitronix ST7920 is a controller for monochrome dot-matrix graphical LCDs,
> +  most commonly used for 128x64 pixel displays.
> +  This binding supports connecting the display via a standard SPI bus.

Drop last sentence. You should write complete bindings for complete
hardware. Binding cannot support something and should not cover only one
bus.

> +
> +properties:
> +  compatible:
> +    const: sitronix,st7920
> +
> +  reg:
> +    description: The chip-select number for the device on the SPI bus.
> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    description: Maximum SPI clock frequency in Hz.
> +    maximum: 600000
> +
> +  spi-cs-high:
> +    type: boolean
> +    description: Indicates the chip select is active high.

No supplies?

> +
> +required:
> +  - compatible
> +  - reg
> +  - spi-max-frequency

Missing allOf: with ref to spi properties

> +
> +additionalProperties: false

And this is unevaluatedProperties. Please look at other examples of
devices like that.

> +
> +examples:
> +  - |
> +    // Example: ST7920 connected to an SPI bus
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    spi0 {

spi {

> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        display@0 {
> +            compatible = "sitronix,st7920";
> +            reg = <0>; // Chip select 0

Drop comment, obvious.

> +            spi-max-frequency = <600000>;
> +            spi-cs-high;
> +        };
> +    };
> 


Best regards,
Krzysztof

On Wed, Aug 06, 2025 at 02:48:10PM +0200, Iker Pedrosa wrote:
> Add binding for Sitronix ST7920 display.
> 
> Signed-off-by: Iker Pedrosa <ikerpedrosam@gmail.com>
> ---
>  .../bindings/display/sitronix,st7920.yaml          | 55 ++++++++++++++++++++++
>  1 file changed, 55 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/display/sitronix,st7920.yaml b/Documentation/devicetree/bindings/display/sitronix,st7920.yaml
> new file mode 100644
> index 0000000000000000000000000000000000000000..caee85f98c6d242dfab73729210f8c34b23a3a99
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/sitronix,st7920.yaml
> @@ -0,0 +1,55 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/display/sitronix,st7920.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Sitronix ST7920 LCD Display Controllers
> +
> +maintainers:
> +  - Iker Pedrosa <ikerpedrosam@gmail.com>
> +
> +description: |
> +  The Sitronix ST7920 is a controller for monochrome dot-matrix graphical LCDs,
> +  most commonly used for 128x64 pixel displays.
> +  This binding supports connecting the display via a standard SPI bus.
> +
> +properties:
> +  compatible:
> +    const: sitronix,st7920
> +
> +  reg:
> +    description: The chip-select number for the device on the SPI bus.
> +    maxItems: 1
> +
> +  spi-max-frequency:
> +    description: Maximum SPI clock frequency in Hz.
> +    maximum: 600000
> +
> +  spi-cs-high:
> +    type: boolean
> +    description: Indicates the chip select is active high.

Don't redefine this, it's defined in spi-peripheral-props.yaml:
  spi-cs-high:
    $ref: /schemas/types.yaml#/definitions/flag
    description:
      The device requires the chip select active high.

spi-max-frequency's type comes from there, so you need it for that too.


> +
> +required:
> +  - compatible
> +  - reg
> +  - spi-max-frequency
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    // Example: ST7920 connected to an SPI bus
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    spi0 {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        display@0 {
> +            compatible = "sitronix,st7920";
> +            reg = <0>; // Chip select 0
> +            spi-max-frequency = <600000>;
> +            spi-cs-high;
> +        };
> +    };
> 
> -- 
> 2.50.1
>