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

[Kieran Bingham]

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? 

> +                *
> +                * See: https://patchwork.linuxtv.org/project/linux-media/patch/20221106171129.166892-2-nicholas@rothemail.net/#142267
> +                */
> +               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
>