On Monday, June 27, 2011 23:10:49 Mauro Carvalho Chehab wrote:
> Em 07-06-2011 12:05, Hans Verkuil escreveu:
> > From: Hans Verkuil <hans.verk...@cisco.com>
> >
> > It is a bit tricky to handle autogain/gain type scenerios correctly. Such
> > controls need to be clustered and the V4L2_CTRL_FLAG_UPDATE should be set on
> > the autofoo controls. In addition, the manual controls should be marked
> > inactive when the automatic mode is on, and active when the manual mode is
> > on.
> > This also requires specialized volatile handling.
> >
> > The chances of drivers doing all these things correctly are pretty remote.
> > So a new v4l2_ctrl_auto_cluster function was added that takes care of these
> > issues.
> >
> > Signed-off-by: Hans Verkuil <hans.verk...@cisco.com>
> > ---
> > drivers/media/video/v4l2-ctrls.c | 69
> > +++++++++++++++++++++++++++++++------
> > include/media/v4l2-ctrls.h | 45 ++++++++++++++++++++++++
> > 2 files changed, 102 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/media/video/v4l2-ctrls.c
> > b/drivers/media/video/v4l2-ctrls.c
> > index a46d5c1..c39ab0c 100644
> > --- a/drivers/media/video/v4l2-ctrls.c
> > +++ b/drivers/media/video/v4l2-ctrls.c
> > @@ -39,6 +39,20 @@ struct ctrl_helper {
> > bool handled;
> > };
> >
> > +/* Small helper function to determine if the autocluster is set to manual
> > + mode. In that case the is_volatile flag should be ignored. */
> > +static bool is_cur_manual(const struct v4l2_ctrl *master)
> > +{
> > + return master->is_auto && master->cur.val == master->manual_mode_value;
> > +}
> > +
> > +/* Same as above, but this checks the against the new value instead of the
> > + current value. */
> > +static bool is_new_manual(const struct v4l2_ctrl *master)
> > +{
> > + return master->is_auto && master->val == master->manual_mode_value;
> > +}
> > +
> > /* Returns NULL or a character pointer array containing the menu for
> > the given control ID. The pointer array ends with a NULL pointer.
> > An empty string signifies a menu entry that is invalid. This allows
> > @@ -643,7 +657,7 @@ static int ctrl_is_volatile(struct v4l2_ext_control *c,
> > }
> >
> > /* Copy the new value to the current value. */
> > -static void new_to_cur(struct v4l2_ctrl *ctrl)
> > +static void new_to_cur(struct v4l2_ctrl *ctrl, bool update_inactive)
> > {
> > if (ctrl == NULL)
> > return;
> > @@ -659,6 +673,11 @@ static void new_to_cur(struct v4l2_ctrl *ctrl)
> > ctrl->cur.val = ctrl->val;
> > break;
> > }
> > + if (update_inactive) {
> > + ctrl->flags &= ~V4L2_CTRL_FLAG_INACTIVE;
> > + if (!is_cur_manual(ctrl->cluster[0]))
> > + ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
> > + }
> > }
> >
> > /* Copy the current value to the new value */
> > @@ -1166,7 +1185,7 @@ void v4l2_ctrl_cluster(unsigned ncontrols, struct
> > v4l2_ctrl **controls)
> > int i;
> >
> > /* The first control is the master control and it must not be NULL */
> > - BUG_ON(controls[0] == NULL);
> > + BUG_ON(ncontrols == 0 || controls[0] == NULL);
> >
> > for (i = 0; i < ncontrols; i++) {
> > if (controls[i]) {
> > @@ -1177,6 +1196,28 @@ void v4l2_ctrl_cluster(unsigned ncontrols, struct
> > v4l2_ctrl **controls)
> > }
> > EXPORT_SYMBOL(v4l2_ctrl_cluster);
> >
> > +void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl
> > **controls,
> > + u8 manual_val, bool set_volatile)
> > +{
> > + struct v4l2_ctrl *master = controls[0];
> > + u32 flag;
> > + int i;
> > +
> > + v4l2_ctrl_cluster(ncontrols, controls);
> > + WARN_ON(ncontrols <= 1);
> > + master->is_auto = true;
> > + master->manual_mode_value = manual_val;
> > + master->flags |= V4L2_CTRL_FLAG_UPDATE;
> > + flag = is_cur_manual(master) ? 0 : V4L2_CTRL_FLAG_INACTIVE;
> > +
> > + for (i = 1; i < ncontrols; i++)
>
> Hmm... the first control _should_ be the autogain one. This is documented at
> the ABI
> description, but it would be good to have a comment about there at the *.h
> file.
Huh? It's there already:
* @controls: The cluster control array of size @ncontrols. The first control
* must be the 'auto' control (e.g. autogain, autoexposure, etc.)
Regards,
Hans
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