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Date:   Wed, 2 Jun 2021 17:37:26 +0300
From:   Sakari Ailus <sakari.ailus@iki.fi>
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     Martin Kepplinger <martin.kepplinger@puri.sm>, mchehab@kernel.org,
        devicetree@vger.kernel.org, kernel@puri.sm,
        krzysztof.kozlowski@canonical.com, linux-kernel@vger.kernel.org,
        linux-media@vger.kernel.org, paul.kocialkowski@bootlin.com,
        robh@kernel.org, shawnx.tu@intel.com
Subject: Re: [PATCH v2 2/5] dt-bindings: media: document SK Hynix Hi-846 MIPI
 CSI-2 8M pixel sensor
Message-ID: <20210602143726.GZ3@valkosipuli.retiisi.eu>
References: <20210528081336.3858700-1-martin.kepplinger@puri.sm>
 <20210528081336.3858700-3-martin.kepplinger@puri.sm>
 <20210602135137.GW3@valkosipuli.retiisi.eu>
 <YLeQGjDdTX0iohZ0@pendragon.ideasonboard.com>
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In-Reply-To: <YLeQGjDdTX0iohZ0@pendragon.ideasonboard.com>
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Hi Laurent,

On Wed, Jun 02, 2021 at 05:05:14PM +0300, Laurent Pinchart wrote:
> On Wed, Jun 02, 2021 at 04:51:37PM +0300, Sakari Ailus wrote:
> > Hi Martin,
> > 
> > On Fri, May 28, 2021 at 10:13:33AM +0200, Martin Kepplinger wrote:
> > > Document the bindings used for the SK Hynix Hi-846 CMOS camera driver.
> > > 
> > > Signed-off-by: Martin Kepplinger <martin.kepplinger@puri.sm>
> > 
> > Could you read Documentation/driver-api/media/camera-sensor.rst, please?
> > 
> > I believe you'll need assigned-clock-rates device property as well as
> 
> I dn't think assigned-clock-rates should be part of the bindings, it's a
> mechanism that can be used in any DT device node.

What if it's required?

> 
> > link-frequencies endpoint property.
> > 
> > > ---
> > >  .../bindings/media/i2c/hynix,hi846.yaml       | 99 +++++++++++++++++++
> > >  1 file changed, 99 insertions(+)
> > >  create mode 100644 Documentation/devicetree/bindings/media/i2c/hynix,hi846.yaml
> > > 
> > > diff --git a/Documentation/devicetree/bindings/media/i2c/hynix,hi846.yaml b/Documentation/devicetree/bindings/media/i2c/hynix,hi846.yaml
> > > new file mode 100644
> > > index 000000000000..2991108e23e5
> > > --- /dev/null
> > > +++ b/Documentation/devicetree/bindings/media/i2c/hynix,hi846.yaml
> > > @@ -0,0 +1,99 @@
> > > +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> > > +%YAML 1.2
> > > +---
> > > +$id: http://devicetree.org/schemas/media/i2c/hynix,hi846.yaml#
> > > +$schema: http://devicetree.org/meta-schemas/core.yaml#
> > > +
> > > +title: SK Hynix Hi-846 1/4" 8M Pixel MIPI CSI-2 sensor
> > > +
> > > +maintainers:
> > > +  - Martin Kepplinger <martin.kepplinger@puri.sm>
> > > +
> > > +description: |-
> > > +  The Hi-846 is a raw image sensor with an MIPI CSI-2 image data
> > > +  interface and CCI (I2C compatible) control bus. The output format
> > > +  is 10bit Bayer.
> > 
> > Virtually all Bayer sensors can do 8 bpp, too. I'd drop the sentence
> 
> Not this one according to its datasheet (we can't rule out that this
> would be possible an undocumented of course).

Ok, fair enough.

> 
> > mentoning 10 bits.
> > 
> > > +
> > > +properties:
> > > +  compatible:
> > > +    const: hynix,hi846
> > > +
> > > +  reg:
> > > +    description: I2C device address.
> > > +    maxItems: 1
> > > +
> > > +  clocks:
> > > +    description: Reference to the mclk clock.
> > > +    maxItems: 1
> > > +
> > > +  clock-names:
> > > +    const: mclk
> > > +
> > > +  rst-gpios:
> > > +    description: Reference to the GPIO connected to the reset pin. Active low.
> > > +    maxItems: 1
> > > +
> > > +  vdd-supply:
> > > +    description: Definition of the regulator used as 1.8V digital power supply.
> > > +
> > > +  port:
> > > +    $ref: /schemas/graph.yaml#/properties/port
> > > +    additionalProperties: false
> > > +
> > > +    properties:
> > > +      endpoint:
> > > +        $ref: /schemas/media/video-interfaces.yaml#
> > > +        unevaluatedProperties: false
> > > +
> > > +        properties:
> > > +          data-lanes:
> > > +            oneOf:
> > > +              - items:
> > > +                  - const: 1
> > > +                  - const: 2
> > > +                  - const: 3
> > > +                  - const: 4
> > > +              - items:
> > > +                  - const: 1
> > > +                  - const: 2
> > > +
> > > +        required:
> > > +          - data-lanes
> > > +
> > > +required:
> > > +  - compatible
> > > +  - reg
> > > +  - clocks
> > > +  - clock-names
> > > +  - rst-gpios
> > > +  - vdd-supply
> > > +  - port
> > > +
> > > +additionalProperties: false
> > > +
> > > +examples:
> > > +  - |
> > > +    #include <dt-bindings/gpio/gpio.h>
> > > +
> > > +    i2c {
> > > +        #address-cells = <1>;
> > > +        #size-cells = <0>;
> > > +
> > > +        hi846: camera@20 {
> > > +            compatible = "hynix,hi846";
> > > +            reg = <0x20>;
> > > +            clocks = <&clk>;
> > > +            clock-names = "mclk";
> > > +            vdd-supply = <&reg_camera_pwr_en>; /* 1.8v */
> > > +            rst-gpios = <&gpio1 25 GPIO_ACTIVE_LOW>;
> > > +
> > > +            port {
> > > +                camera_out: endpoint {
> > > +                    remote-endpoint = <&csi1_ep1>;
> > > +                    data-lanes = <1 2>;
> > > +                };
> > > +            };
> > > +        };
> > > +    };
> > > +
> > > +...
> 
> -- 
> Regards,
> 
> Laurent Pinchart

-- 
Sakari Ailus