Messages in this thread | | | Subject | Re: [PATCH 1/1] v4l: Add camera voice coil lens control class, current control | From | Ivaylo Dimitrov <> | Date | Mon, 13 Jun 2016 00:48:15 +0300 |
| |
Hi,
On 12.06.2016 23:41, Sakari Ailus wrote: > From: Sakari Ailus <sakari.ailus@iki.fi> > > Add a V4L2 control class for voice coil lens driver devices. These are > simple devices that are used to move a camera lens from its resting > position. > > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com> > --- > Hi Pavel, > > I also don't think the FOCUS_ABSOLUTE controls is a really good one for > the voice coil lens current. I expect more voice coil lens controls > (linear vs. PWM mode, ringing compensation...) to be needed so I think > it's worth a new class. >
Right, I still think movement mode should be standard control :)
> Cc others, too... > > Kind regards, > Sakari > > Documentation/DocBook/media/v4l/controls.xml | 55 +++++++++++++++++++++++++++- > include/uapi/linux/v4l2-controls.h | 7 ++++ > 2 files changed, 61 insertions(+), 1 deletion(-) > > diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml > index e2e5484..aa7169c 100644 > --- a/Documentation/DocBook/media/v4l/controls.xml > +++ b/Documentation/DocBook/media/v4l/controls.xml > @@ -5502,4 +5502,57 @@ receiving given frequency when that control is set. This is a read-only control. > </tgroup> > </table> > </section> > -</section> > + > + <section id="voice-coil-controls"> > + <title>Voice Coil Control Reference</title> > + > + <para>The Voice Coil class controls are used to control voice > + coil lens devices. These are very simple devices that consist of > + a voice coil, a spring and a lens. The current applied on a
There should be a magnet as well.
> + voice coil is used to move the lens away from the resting > + position which typically is (close to) infinity.</para> > + > + <table pgwide="1" frame="none" id="voice-coil-control-id"> > + <title>Voice Coil Control IDs</title> > + > + <tgroup cols="4"> > + <colspec colname="c1" colwidth="1*" /> > + <colspec colname="c2" colwidth="6*" /> > + <colspec colname="c3" colwidth="2*" /> > + <colspec colname="c4" colwidth="6*" /> > + <spanspec namest="c1" nameend="c2" spanname="id" /> > + <spanspec namest="c2" nameend="c4" spanname="descr" /> > + <thead> > + <row> > + <entry spanname="id" align="left">ID</entry> > + <entry align="left">Type</entry> > + </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry> > + </row> > + </thead> > + <tbody valign="top"> > + <row><entry></entry></row> > + <row> > + <entry spanname="id"><constant>V4L2_CID_VOICE_COIL_CLASS</constant> </entry> > + <entry>class</entry> > + </row><row><entry spanname="descr">The Voice Coil class > +descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a > +description of this control class.</entry> > + </row> > + <row> > + <entry spanname="id"><constant>V4L2_CID_VOICE_COIL_CURRENT</constant> </entry> > + <entry>integer</entry>
I think this is no better than FOCUS_ABSOLUTE - nor "absolute" neither "current" give any idea where is the lens (relatively to the rest position) without userspace doing some calculations. What about V4L2_CID_VOICE_COIL_POSITION, 0.000%-100.000% (pcm units)?
> + </row><row><entry spanname="descr">Current applied on a > + voice coil. The more current is applied, the more is the > + position of the lens moved from its resting position. Do > + note that there may be a ringing effect; the lens will > + oscillate after changing the current applied unless the > + device implements ringing compensation. > + </entry> > + </row> > + </tbody> > + </tgroup> > + </table> > + > + </section> > + > + </section> > diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h > index b6a357a..c6b1261 100644 > --- a/include/uapi/linux/v4l2-controls.h > +++ b/include/uapi/linux/v4l2-controls.h > @@ -62,6 +62,7 @@ > #define V4L2_CTRL_CLASS_FM_RX 0x00a10000 /* FM Receiver controls */ > #define V4L2_CTRL_CLASS_RF_TUNER 0x00a20000 /* RF tuner controls */ > #define V4L2_CTRL_CLASS_DETECT 0x00a30000 /* Detection controls */ > +#define V4L2_CTRL_CLASS_VOICE_COIL 0x00a40000 /* Voice coil lens driver */ > > /* User-class control IDs */ > > @@ -974,4 +975,10 @@ enum v4l2_detect_md_mode { > #define V4L2_CID_DETECT_MD_THRESHOLD_GRID (V4L2_CID_DETECT_CLASS_BASE + 3) > #define V4L2_CID_DETECT_MD_REGION_GRID (V4L2_CID_DETECT_CLASS_BASE + 4) > > +/* Voice coil lens driver control IDs defined by V4L2 */ > +#define V4L2_CID_VOICE_COIL_CLASS_BASE (V4L2_CTRL_CLASS_VOICE_COIL | 0x900) > +#define V4L2_CID_VOICE_COIL_CLASS (V4L2_CTRL_CLASS_VOICE_COIL | 1) > + > +#define V4L2_CID_VOICE_COIL_CURRENT (V4L2_CID_VOICE_COIL_CLASS_BASE + 1) > + > #endif >
Ivo
| |