[v2,1/2] dt-bindings: gpio: Binding for Realtek Otto GPIO

Add a binding description for Realtek's GPIO controller found on several
of their MIPS-based SoCs (codenamed Otto), such as the RTL838x and
RTL839x series of switch SoCs.

A fallback binding 'realtek,otto-gpio' is provided for cases where the
actual port ordering is not known yet, and enabling the interrupt
controller may result in uncaught interrupts.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 .../bindings/gpio/gpio-realtek-otto.yaml      | 80 +++++++++++++++++++
 1 file changed, 80 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/gpio-realtek-otto.yaml

On Mon, Mar 15, 2021 at 08:08:05PM +0100, Sander Vanheule wrote:
> Add a binding description for Realtek's GPIO controller found on several
> of their MIPS-based SoCs (codenamed Otto), such as the RTL838x and
> RTL839x series of switch SoCs.
> 
> A fallback binding 'realtek,otto-gpio' is provided for cases where the
> actual port ordering is not known yet, and enabling the interrupt
> controller may result in uncaught interrupts.
> 
> Signed-off-by: Sander Vanheule <sander@svanheule.net>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  .../bindings/gpio/gpio-realtek-otto.yaml      | 80 +++++++++++++++++++

Use compatible string: realtek,otto-gpio.yaml

>  1 file changed, 80 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/gpio-realtek-otto.yaml
> 
> diff --git a/Documentation/devicetree/bindings/gpio/gpio-realtek-otto.yaml b/Documentation/devicetree/bindings/gpio/gpio-realtek-otto.yaml
> new file mode 100644
> index 000000000000..3e8151e3a169
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/gpio-realtek-otto.yaml
> @@ -0,0 +1,80 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/gpio-realtek-otto.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Realtek Otto GPIO controller
> +
> +maintainers:
> +  - Sander Vanheule <sander@svanheule.net>
> +  - Bert Vermeulen <bert@biot.com>
> +
> +description: |
> +  Realtek's GPIO controller on their MIPS switch SoCs (Otto platform) consists
> +  of two banks of 32 GPIOs. These GPIOs can generate edge-triggered interrupts.
> +  Each bank's interrupts are cascased into one interrupt line on the parent
> +  interrupt controller, if provided.
> +  This binding allows defining a single bank in the devicetree. The interrupt
> +  controller is not supported on the fallback compatible name, which only
> +  allows for GPIO port use.
> +
> +properties:
> +  $nodename:
> +    pattern: "^gpio@[0-9a-f]+$"
> +
> +  compatible:
> +    oneOf:
> +      - items:
> +          - enum:
> +              - realtek,rtl8380-gpio
> +              - realtek,rtl8390-gpio
> +          - const: realtek,otto-gpio
> +      - const: realtek,otto-gpio

This should be dropped. You should always have an SoC specific 
compatible.

> +
> +  reg:
> +    maxItems: 1
> +
> +  "#gpio-cells":
> +    const: 2
> +
> +  gpio-controller: true
> +
> +  ngpios:
> +    minimum: 1
> +    maximum: 32
> +
> +  interrupt-controller: true
> +
> +  "#interrupt-cells":
> +    const: 2
> +
> +  interrupts:
> +    maxItems: 1
> +
> +required:
> +  - compatible
> +  - reg
> +  - "#gpio-cells"
> +  - gpio-controller
> +
> +additionalProperties: false
> +
> +dependencies:
> +  interrupt-controller: [ interrupts ]
> +
> +examples:
> +  - |
> +      gpio@3500 {
> +        compatible = "realtek,rtl8380-gpio", "realtek,otto-gpio";
> +        reg = <0x3500 0x1c>;
> +        gpio-controller;
> +        #gpio-cells = <2>;
> +        ngpios = <24>;
> +        interrupt-controller;
> +        #interrupt-cells = <2>;
> +        interrupt-parent = <&rtlintc>;
> +        interrupts = <23>;
> +      };
> +
> +...
> -- 
> 2.30.2
>