Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Wed, 10 Feb 2021 12:41:38 -0600
From:   Rob Herring <robh@kernel.org>
To:     Oleksij Rempel <o.rempel@pengutronix.de>
Cc:     William Breathitt Gray <vilhelm.gray@gmail.com>,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        David Jander <david@protonic.nl>,
        Robin van der Gracht <robin@protonic.nl>,
        linux-iio@vger.kernel.org,
        Linus Walleij <linus.walleij@linaro.org>,
        Jonathan Cameron <jic23@kernel.org>
Subject: Re: [PATCH v5 1/2] dt-bindings: counter: add event-counter binding
Message-ID: <20210210184138.GA2504266@robh.at.kernel.org>
References: <20210208135347.18494-1-o.rempel@pengutronix.de>
 <20210208135347.18494-2-o.rempel@pengutronix.de>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20210208135347.18494-2-o.rempel@pengutronix.de>
Precedence: bulk

On Mon, Feb 08, 2021 at 02:53:46PM +0100, Oleksij Rempel wrote:
> Add binding for the event counter node
> 
> Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
> ---
>  .../bindings/counter/event-counter.yaml       | 56 +++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/counter/event-counter.yaml
> 
> diff --git a/Documentation/devicetree/bindings/counter/event-counter.yaml b/Documentation/devicetree/bindings/counter/event-counter.yaml
> new file mode 100644
> index 000000000000..bd05c1b38f20
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/counter/event-counter.yaml
> @@ -0,0 +1,56 @@
> +# SPDX-License-Identifier: GPL-2.0
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/counter/event-counter.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Event counter
> +
> +maintainers:
> +  - Oleksij Rempel <o.rempel@pengutronix.de>
> +
> +description: |
> +  A generic event counter to measure event frequency. It was developed and used
> +  for agricultural devices to measure rotation speed of wheels or other tools.
> +  Since the direction of rotation is not important, only one signal line is
> +  needed.
> +
> +properties:
> +  compatible:
> +    const: event-counter
> +
> +  interrupts:
> +    maxItems: 1
> +
> +  gpios:
> +    description: Optional diagnostic interface to measure signal level

This description seems wrong in the case of only having a GPIO.

Also, a GPIO only implies polled mode because if the GPIO is interrupt 
capable, 'interrupts' should be required. For gpio-keys, we split the 
compatible strings in this case. I leave it to you if you want to make 
it more explicit.

> +    maxItems: 1
> +
> +required:
> +  - compatible

anyOf:
  - required: [ interrupts ]
  - required: [ gpios ]

> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +
> +    #include <dt-bindings/interrupt-controller/irq.h>
> +    #include <dt-bindings/gpio/gpio.h>
> +
> +    counter-0 {
> +        compatible = "event-counter";
> +        interrupts-extended = <&gpio 0 IRQ_TYPE_EDGE_RISING>;
> +    };
> +
> +    counter-1 {
> +        compatible = "event-counter";
> +        gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
> +    };
> +
> +    counter-2 {
> +        compatible = "event-counter";
> +        interrupts-extended = <&gpio 2 IRQ_TYPE_EDGE_RISING>;
> +        gpios = <&gpio 2 GPIO_ACTIVE_HIGH>;
> +    };
> +
> +...
> -- 
> 2.30.0
>