[libcamera-devel] [PATCH v2] libcamera: Add support for OmniVision OV8858

[Jacopo Mondi]

Hi Kieran

On Wed, Jan 25, 2023 at 10:54:26AM +0000, Kieran Bingham via libcamera-devel wrote:
> Quoting Jacopo Mondi via libcamera-devel (2023-01-25 09:05:28)
> > From: Nicholas Roth <nicholas at rothemail.net>
> >
> > Support for the OmniVision OV8858 sensor is scheduled for inclusion in
> > the Linux kernel in version v6.3.
> >
> > Add support for the sensor in libcamera by providing static properties
> > and a camera sensor helper in libipa.
> >
> > The camera sensor helper expresses analogue gain increments in 1/128
> > step which differs from what is reported in the sensor documentation in
> > section "5.8 manual exposure compensation/ manual gain compensation" [0]
> >
> > A more detailed analysis of the sensor gain model is reported at:
> > https://patchwork.linuxtv.org/project/linux-media/patch/20221106171129.166892-2-nicholas@rothemail.net/#142267
> >
> > Record with a \todo note a reference to discussion on the gain model
> > implementation.
> >
> > Signed-off-by: Nicholas Roth <nicholas at rothemail.net>
> > Signed-off-by: Jacopo Mondi <jacopo.mondi at ideasonboard.com>
> > ---
> >
> > Compared to initial Nicholas' submission:
> > - Change gain step to 128 (link to the driver discussion)
> > - Add fadeToGray test patter and adjust comment
> >
> > ---
> >  src/ipa/libipa/camera_sensor_helper.cpp    | 18 ++++++++++++++++++
> >  src/libcamera/camera_sensor_properties.cpp | 13 +++++++++++++
> >  2 files changed, 31 insertions(+)
> >
> > diff --git a/src/ipa/libipa/camera_sensor_helper.cpp b/src/ipa/libipa/camera_sensor_helper.cpp
> > index 3d8a2835fa28..52e11dfb8ca2 100644
> > --- a/src/ipa/libipa/camera_sensor_helper.cpp
> > +++ b/src/ipa/libipa/camera_sensor_helper.cpp
> > @@ -505,6 +505,24 @@ public:
> >  };
> >  REGISTER_CAMERA_SENSOR_HELPER("ov5693", CameraSensorHelperOv5693)
> >
> > +class CameraSensorHelperOv8858 : public CameraSensorHelper
> > +{
> > +public:
> > +       CameraSensorHelperOv8858()
> > +       {
> > +               gainType_ = AnalogueGainLinear;
> > +
> > +               /*
> > +                * \todo Use an increment step of 1/128 which differs from
> > +                * what the sensor manual describes.
>
> This sounds like the todo is to *use* a step of 128, but isn't that what
> it's already doing?
>

Right :)

I can change it to
                     * \todo Validate the selected 1/128 step value
                     * as it differs from what the sensor manual
                     * describes
                     *
                     * See: https://patchwork.linuxtv.org/project/linux-media/patch/20221106171129.166892-2-nicholas@rothemail.net/#142267
                     */

When applying


> > +               gainConstants_.linear = { 1, 0, 0, 128 };
> > +       }
> > +};
> > +REGISTER_CAMERA_SENSOR_HELPER("ov8858", CameraSensorHelperOv8858)
> > +
> >  class CameraSensorHelperOv8865 : public CameraSensorHelper
> >  {
> >  public:
> > diff --git a/src/libcamera/camera_sensor_properties.cpp b/src/libcamera/camera_sensor_properties.cpp
> > index c3c2caced906..7f6816e72773 100644
> > --- a/src/libcamera/camera_sensor_properties.cpp
> > +++ b/src/libcamera/camera_sensor_properties.cpp
> > @@ -167,6 +167,19 @@ const CameraSensorProperties *CameraSensorProperties::get(const std::string &sen
> >                                  */
> >                         },
> >                 } },
> > +               { "ov8858", {
> > +                       .unitCellSize = { 1120, 1120 },
> > +                       .testPatternModes = {
> > +                               { controls::draft::TestPatternModeOff, 0 },
> > +                               { controls::draft::TestPatternModeColorBars, 1 },
> > +                               { controls::draft::TestPatternModeColorBarsFadeToGray, 2 },
> > +                               /*
> > +                                * No corresponding test patter mode
>
> s/patter/pattern/
>
>
> > +                                * 3: "Vertical Color Bar Type 3",
> > +                                * 4: "Vertical Color Bar Type 4"
> > +                                */
> > +                       },
> > +               } },
> >                 { "ov8865", {
> >                         .unitCellSize = { 1400, 1400 },
> >                         .testPatternModes = {
> > --
> > 2.39.0
> >