linux-kernel - Re: [PATCH v2 1/2] [media] imx214: device tree binding

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Date:   Fri, 21 Sep 2018 13:01:44 +0200
From:   Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
To:     Laurent Pinchart <laurent.pinchart@...asonboard.com>
Cc:     Sakari Ailus <sakari.ailus@...ux.intel.com>,
        Hans Verkuil <hans.verkuil@...co.com>,
        Mauro Carvalho Chehab <mchehab+samsung@...nel.org>,
        LKML <linux-kernel@...r.kernel.org>,
        linux-media <linux-media@...r.kernel.org>,
        devicetree@...r.kernel.org
Subject: Re: [PATCH v2 1/2] [media] imx214: device tree binding

Hi Laurent

Thanks for your review!
On Fri, Sep 21, 2018 at 12:38 PM Laurent Pinchart
<laurent.pinchart@...asonboard.com> wrote:
>
> Hi Ricardo,
>
> Thank you for the patch.
>
> On Friday, 21 September 2018 13:09:19 EEST Ricardo Ribalda Delgado wrote:
> > Document bindings for imx214 v4l2 driver.
>
> Those are bindings for the IMX214 camera sensor, not for its V4L2 driver.
>
> > Cc: devicetree@...r.kernel.org
> > Signed-off-by: Ricardo Ribalda Delgado <ricardo.ribalda@...il.com>
> > ---
> >  .../devicetree/bindings/media/i2c/imx214.txt  | 51 +++++++++++++++++++
> >  1 file changed, 51 insertions(+)
> >  create mode 100644 Documentation/devicetree/bindings/media/i2c/imx214.txt
> >
> > diff --git a/Documentation/devicetree/bindings/media/i2c/imx214.txt
> > b/Documentation/devicetree/bindings/media/i2c/imx214.txt new file mode
> > 100644
> > index 000000000000..4ff76d96332e
> > --- /dev/null
> > +++ b/Documentation/devicetree/bindings/media/i2c/imx214.txt
> > @@ -0,0 +1,51 @@
> > +* Sony 1/3.06-Inch 13.13Mp CMOS Digital Image Sensor
> > +
> > +The Sony imx214 is a 1/3.06-inch CMOS active pixel digital image sensor
> > with +an active array size of 4224H x 3176V. It is programmable through I2C
> > +interface.
>
> s/I2C interface/an I2C interface/
>
> > The I2C address can be configured to to 0x1a or 0x10, depending
> > on +how is wired.
>
> Maybe "depending on how the hardware is wired" ?
>
> > +Image data is sent through MIPI CSI-2, which is configured as 4 lanes
> > +at 1440 Mbps.
>
> Can the sensor use less lanes than 4, or is it fixed ?
>
> > +Required Properties:
> > +- compatible: value should be "sony,imx214" for imx214 sensor
> > +- reg: I2C bus address of the device
> > +- enable-gpios: Sensor enable GPIO
>
> Maybe "GPIO descriptor for the enable pin" ?
>
> > +- vdddo-supply: Chip digital IO regulator (1.8V).
> > +- vdda-supply: Chip analog regulator (2.7V).
> > +- vddd-supply: Chip digital core regulator (1.12V).
> > +- clocks = Reference to the xclk clock.
> > +- clock-names = Should be "xclk".
>
> If there's a single clock, is the name mandatory ?

The drivers is checking for that name.  I am removing that constrain
from the driver and fixing the doc

>
> > +- clock-frequency = Frequency of the xclk clock. Should be <24000000>;
>
> The frequency of the clock can be queried at runtime. If you want to hardcode
> a specific frequency in DT, you should use the assigned-clock-rates property.

With the current register_tables I only support that input clock.

>
> > +Optional Properties:
> > +- flash-leds: See ../video-interfaces.txt
> > +- lens-focus: See ../video-interfaces.txt
> > +
> > +The imx274 device node should contain one 'port' child node with
> > +an 'endpoint' subnode. For further reading on port node refer to
> > +Documentation/devicetree/bindings/media/video-interfaces.txt.
> > +
> > +Example:
> > +
> > +     camera_rear@1a {
> > +             status = "okay";
>
> Isn't that the default ?
>
> > +             compatible = "sony,imx214";
> > +             reg = <0x1a>;
> > +             vdddo-supply = <&pm8994_lvs1>;
> > +             vddd-supply = <&camera_vddd_1v12>;
> > +             vdda-supply = <&pm8994_l17>;
> > +             lens-focus = <&ad5820>;
> > +             enable-gpios = <&msmgpio 25 GPIO_ACTIVE_HIGH>;
> > +             clocks = <&mmcc CAMSS_MCLK0_CLK>;
> > +             clock-names = "xclk";
> > +             clock-frequency = <24000000>;
> > +             port {
> > +                             imx214_ep: endpoint {
>
> Incorrect indentation ?
>
> > +                             clock-lanes = <1>;
> > +                             data-lanes = <0 2 3 4>;
>
> Those properties are not documented. The data-lanes value is peculiar, does
> the sensor support lanes remapping ?

I do not believe that the sensor supports lanes remapping

That is the configuration used on the db820c. Sensors with two CSI lanes have:

                             clock-lanes = <1>;
                             data-lanes = <0 2>;

I just extended it to 4 lanes... but I just tried < 1 2 3 4 > and also
works fine... so I will fix that.

>
> > +                             remote-endpoint = <&csiphy0_ep>;
> > +                     };
> > +             };
> > +     };
>
>
> --
> Regards,
>
> Laurent Pinchart
>
>
>

I am adding all your fixes to my github tree


https://github.com/ribalda/linux/commits/imx214-v3

After people had time to give their reviews I will send v3 to the list
(do not want to spam again the list) :P

Thanks again

-- 
Ricardo Ribalda