On 06/09/17 15:21, Sakari Ailus wrote: > Add V4L2_CID_DIGITAL_GAIN to control explicitly digital gain. > > We already have analogue gain control which the digital gain control > complements. Typically higher quality images are obtained using analogue > gain only as the digital gain does not add information to the image > (rather it may remove it). > > Signed-off-by: Sakari Ailus <[email protected]>
Acked-by: Hans Verkuil <[email protected]> Regards, Hans > --- > Documentation/media/uapi/v4l/extended-controls.rst | 7 +++++++ > drivers/media/v4l2-core/v4l2-ctrls.c | 1 + > include/uapi/linux/v4l2-controls.h | 2 +- > 3 files changed, 9 insertions(+), 1 deletion(-) > > diff --git a/Documentation/media/uapi/v4l/extended-controls.rst > b/Documentation/media/uapi/v4l/extended-controls.rst > index 76c5b1a..9acc9cad 100644 > --- a/Documentation/media/uapi/v4l/extended-controls.rst > +++ b/Documentation/media/uapi/v4l/extended-controls.rst > @@ -3021,6 +3021,13 @@ Image Process Control IDs > The video deinterlacing mode (such as Bob, Weave, ...). The menu items > are > driver specific and are documented in :ref:`v4l-drivers`. > > +``V4L2_CID_DIGITAL_GAIN (integer)`` > + Digital gain is the value by which all colour components > + are multiplied by. Typically the digital gain applied is the > + control value divided by e.g. 0x100, meaning that to get no > + digital gain the control value needs to be 0x100. The no-gain > + configuration is also typically the default. > + > > .. _dv-controls: > > diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c > b/drivers/media/v4l2-core/v4l2-ctrls.c > index 5aed7bd..36eede3 100644 > --- a/drivers/media/v4l2-core/v4l2-ctrls.c > +++ b/drivers/media/v4l2-core/v4l2-ctrls.c > @@ -886,6 +886,7 @@ const char *v4l2_ctrl_get_name(u32 id) > case V4L2_CID_PIXEL_RATE: return "Pixel Rate"; > case V4L2_CID_TEST_PATTERN: return "Test Pattern"; > case V4L2_CID_DEINTERLACING_MODE: return "Deinterlacing Mode"; > + case V4L2_CID_DIGITAL_GAIN: return "Digital Gain"; > > /* DV controls */ > /* Keep the order of the 'case's the same as in v4l2-controls.h! */ > diff --git a/include/uapi/linux/v4l2-controls.h > b/include/uapi/linux/v4l2-controls.h > index 0d2e1e0..0cdb8eb 100644 > --- a/include/uapi/linux/v4l2-controls.h > +++ b/include/uapi/linux/v4l2-controls.h > @@ -893,7 +893,7 @@ enum v4l2_jpeg_chroma_subsampling { > #define V4L2_CID_PIXEL_RATE (V4L2_CID_IMAGE_PROC_CLASS_BASE > + 2) > #define V4L2_CID_TEST_PATTERN > (V4L2_CID_IMAGE_PROC_CLASS_BASE + 3) > #define V4L2_CID_DEINTERLACING_MODE (V4L2_CID_IMAGE_PROC_CLASS_BASE > + 4) > - > +#define V4L2_CID_DIGITAL_GAIN > (V4L2_CID_IMAGE_PROC_CLASS_BASE + 5) > > /* DV-class control IDs defined by V4L2 */ > #define V4L2_CID_DV_CLASS_BASE (V4L2_CTRL_CLASS_DV | > 0x900) >
