Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Thu, 19 Mar 2020 17:10:35 +0200
From:   Laurent Pinchart <laurent.pinchart@ideasonboard.com>
To:     Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Cc:     Sakari Ailus <sakari.ailus@linux.intel.com>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>,
        linux-media@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        Lad Prabhakar <prabhakar.csengg@gmail.com>
Subject: Re: [PATCH v4 5/5] media: dt-bindings: media: i2c: convert ov5645
 bindings to json-schema
Message-ID: <20200319151035.GC14585@pendragon.ideasonboard.com>
References: <1584620363-2255-1-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com>
 <1584620363-2255-6-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Disposition: inline
In-Reply-To: <1584620363-2255-6-git-send-email-prabhakar.mahadev-lad.rj@bp.renesas.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Hi Prabhakar,

Thank you for the patch.

On Thu, Mar 19, 2020 at 12:19:23PM +0000, Lad Prabhakar wrote:
> Convert ov5645 bindings to json-schema.

\o/

> 
> Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> ---
>  .../devicetree/bindings/media/i2c/ov5645.txt  |  54 -------
>  .../devicetree/bindings/media/i2c/ov5645.yaml | 140 ++++++++++++++++++
>  2 files changed, 140 insertions(+), 54 deletions(-)
>  delete mode 100644 Documentation/devicetree/bindings/media/i2c/ov5645.txt
>  create mode 100644 Documentation/devicetree/bindings/media/i2c/ov5645.yaml
> 
> diff --git a/Documentation/devicetree/bindings/media/i2c/ov5645.txt b/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> deleted file mode 100644
> index 1c85c78ec58c..000000000000
> --- a/Documentation/devicetree/bindings/media/i2c/ov5645.txt
> +++ /dev/null
> @@ -1,54 +0,0 @@
> -* Omnivision 1/4-Inch 5Mp CMOS Digital Image Sensor
> -
> -The Omnivision OV5645 is a 1/4-Inch CMOS active pixel digital image sensor with
> -an active array size of 2592H x 1944V. It is programmable through a serial I2C
> -interface.
> -
> -Required Properties:
> -- compatible: Value should be "ovti,ov5645".
> -- clocks: Reference to the xclk clock.
> -- clock-names: Should be "xclk".
> -- enable-gpios: Chip enable GPIO. Polarity is GPIO_ACTIVE_HIGH. This corresponds
> -  to the hardware pin PWDNB which is physically active low.
> -- reset-gpios: Chip reset GPIO. Polarity is GPIO_ACTIVE_LOW. This corresponds to
> -  the hardware pin RESETB.
> -- vdddo-supply: Chip digital IO regulator.
> -- vdda-supply: Chip analog regulator.
> -- vddd-supply: Chip digital core regulator.
> -
> -The device node must contain one 'port' child node for its digital output
> -video port, in accordance with the video interface bindings defined in
> -Documentation/devicetree/bindings/media/video-interfaces.txt.
> -
> -Example:
> -
> -	&i2c1 {
> -		...
> -
> -		ov5645: ov5645@3c {
> -			compatible = "ovti,ov5645";
> -			reg = <0x3c>;
> -
> -			enable-gpios = <&gpio1 6 GPIO_ACTIVE_HIGH>;
> -			reset-gpios = <&gpio5 20 GPIO_ACTIVE_LOW>;
> -			pinctrl-names = "default";
> -			pinctrl-0 = <&camera_rear_default>;
> -
> -			clocks = <&clks 200>;
> -			clock-names = "xclk";
> -			assigned-clocks = <&clks 200>;
> -			assigned-clock-rates = <24000000>;
> -
> -			vdddo-supply = <&camera_dovdd_1v8>;
> -			vdda-supply = <&camera_avdd_2v8>;
> -			vddd-supply = <&camera_dvdd_1v2>;
> -
> -			port {
> -				ov5645_ep: endpoint {
> -					clock-lanes = <1>;
> -					data-lanes = <0 2>;
> -					remote-endpoint = <&csi0_ep>;
> -				};
> -			};
> -		};
> -	};
> diff --git a/Documentation/devicetree/bindings/media/i2c/ov5645.yaml b/Documentation/devicetree/bindings/media/i2c/ov5645.yaml
> new file mode 100644
> index 000000000000..4bf58ad210c5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/media/i2c/ov5645.yaml
> @@ -0,0 +1,140 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/media/i2c/ov5645.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Omnivision 1/4-Inch 5Mp CMOS Digital Image Sensor

s/Mp/MP/ ?

> +
> +maintainers:
> +  - Sakari Ailus <sakari.ailus@linux.intel.com>
> +  - Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
> +
> +description: |-
> + The Omnivision OV5645 is a 1/4-Inch CMOS active pixel digital image sensor with
> + an active array size of 2592H x 1944V. It is programmable through a serial I2C
> + interface.
> +
> +properties:
> +  compatible:
> +    const: ovti,ov5645
> +
> +  reg:
> +    description: I2C device address
> +    maxItems: 1
> +
> +  clocks:
> +    maxItems: 1
> +
> +  clock-names:
> +    items:
> +      - const: xclk
> +
> +  assigned-clocks:
> +    maxItems: 1
> +
> +  assigned-clock-rates:
> +     items:
> +     - description: Must be 24MHz (24000000).

These two properties shouldn't be part of the bindings, they're generic.

> +
> +  enable-gpios:
> +    description: |-
> +      Chip enable GPIO. Polarity is GPIO_ACTIVE_HIGH. This corresponds
> +      to the hardware pin PWDNB which is physically active low.

Specifying that the polarity is GPIO_ACTIVE_HIGH is confusing in my
opinion. If there's an inverter on the board, you'll need
GPIO_ACTIVE_LOW. We could possibly drop the sentence, as all GPIOs in DT
are supposed to be active high, but the fact that the GPIO name
corresponds to the opposite of the pin probably has to be documented. I
have no better wording to propose now I'm afraid, but it needs to be
addressed. Maybe Rob or Maxime could help.

> +
> +  reset-gpios:
> +    description: |-
> +      Chip reset GPIO. Polarity is GPIO_ACTIVE_LOW. This corresponds to
> +      the hardware pin RESETB.

Here you could just drop the second sentence, or apply the same fix as
for enable-gpios.

> +
> +  vdddo-supply:
> +    description:
> +      Chip digital IO regulator.

You can move the description on the same line as the "description:" key.
Same below.

> +
> +  vdda-supply:
> +    description:
> +      Chip analog regulator.
> +
> +  vddd-supply:
> +    description:
> +      Chip digital core regulator.
> +
> +  # See ../video-interfaces.txt for more details
> +  port:
> +    type: object
> +    properties:
> +      endpoint:
> +        type: object
> +
> +        properties:
> +          data-lanes:
> +            description: |-
> +              The sensor supports two-lane operation.
> +              For two-lane operation the property must be set to <1 2>.
> +            items:
> +              - const: 1
> +              - const: 2


What if only one lane is wired, does the sensor support that ?

> +
> +          clock-lanes:
> +            description:
> +              should be set to <0> (clock lane on hardware lane 0).
> +            items:
> +              - const: 0
> +
> +          remote-endpoint: true
> +
> +        required:
> +          - data-lanes
> +          - clock-lanes
> +          - remote-endpoint
> +
> +        additionalProperties: false
> +
> +    additionalProperties: false
> +
> +required:
> +  - compatible
> +  - reg
> +  - clocks
> +  - clock-names
> +  - assigned-clocks
> +  - assigned-clock-rates

Those two properties should be dropped.

> +  - enable-gpios
> +  - reset-gpios

Are the GPIOs mandatory ? What if the signals are hardwired on the board
?

> +  - vdddo-supply
> +  - vdda-supply
> +  - vddd-supply
> +  - port
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c1 {

s/i2c1/i2c/

> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        ov5645: sensor@3c {
> +            compatible = "ovti,ov5645";
> +            reg = <0x3c>;
> +            clocks = <&ov5645_cl>;
> +            clock-names = "xclk";
> +            assigned-clocks = <&ov5645_cl>;
> +            assigned-clock-rates = <24000000>;
> +            enable-gpios = <&gpio1 6 /* GPIO_ACTIVE_HIGH */>;
> +            reset-gpios = <&gpio5 20 /* GPIO_ACTIVE_LOW */>;
> +            vdddo-supply = <&camera_dovdd_1v8>;
> +            vdda-supply = <&camera_avdd_2v8>;
> +            vddd-supply = <&camera_dvdd_1v2>;
> +
> +            port {
> +                ov5645_0: endpoint {
> +                    remote-endpoint = <&csi1_ep>;
> +                    clock-lanes = <0>;
> +                    data-lanes = <1 2>;
> +                };
> +            };
> +        };
> +    };
> +
> +...

-- 
Regards,

Laurent Pinchart