[PATCH] libcamera: Add open() and close() in CameraLens

[Kieran Bingham]

Quoting Harvey Yang (2024-10-17 08:39:47)
> From: Han-Lin Chen <hanlinchen at chromium.org>
> 
> This allows pipeline handlers to save some power when a camera is close.

This seems reasonable - but makes me wonder - is there similar
limitations with the CameraSensor class that has a very similar design?


> 
> Signed-off-by: Han-Lin Chen <hanlinchen at chromium.org>
> Co-developed-by: Harvey Yang <chenghaoyang at chromium.org>
> Signed-off-by: Harvey Yang <chenghaoyang at chromium.org>
> ---
>  include/libcamera/internal/camera_lens.h |  4 ++++
>  src/libcamera/camera_lens.cpp            | 17 +++++++++++++++++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/include/libcamera/internal/camera_lens.h b/include/libcamera/internal/camera_lens.h
> index 5a4b993bb..095056791 100644
> --- a/include/libcamera/internal/camera_lens.h
> +++ b/include/libcamera/internal/camera_lens.h
> @@ -26,6 +26,10 @@ public:
>         ~CameraLens();
>  
>         int init();

Should we be calling close() at the end of init()? Perhaps with some
sort of way to make sure if an API call is used on a now closed device
it gets opened again first ? (i.e. mostly perhaps V4L2Device::setControls)?

> +
> +       int open();
> +       void close();
> +
>         int setFocusPosition(int32_t position);
>  
>         const std::string &model() const { return model_; }
> diff --git a/src/libcamera/camera_lens.cpp b/src/libcamera/camera_lens.cpp
> index ccc2a6a65..039f5ad2a 100644
> --- a/src/libcamera/camera_lens.cpp
> +++ b/src/libcamera/camera_lens.cpp
> @@ -76,6 +76,23 @@ int CameraLens::init()
>         return 0;
>  }
>  
> +/**
> + * \brief Open the subdev
> + * \return 0 on success or a negative error code otherwise
> + */
> +int CameraLens::open()
> +{
> +       return subdev_->open();
> +}
> +
> +/**
> + * \brief Close the subdev
> + */
> +void CameraLens::close()
> +{
> +       subdev_->close();
> +}
> +
>  /**
>   * \brief This function sets the focal point of the lens to a specific position.
>   * \param[in] position The focal point of the lens
> -- 
> 2.47.0.rc1.288.g06298d1525-goog
>