On Monday, June 27, 2011 22:57:34 Mauro Carvalho Chehab wrote:
> Em 07-06-2011 12:05, Hans Verkuil escreveu:
> > From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> >
> > 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.verkuil@xxxxxxxxx>
> > ---
> > 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;
>
> You'll have an overflow if manual_val is higher than 31 here.
>
> > + master->flags |= V4L2_CTRL_FLAG_UPDATE;
> > + flag = is_cur_manual(master) ? 0 : V4L2_CTRL_FLAG_INACTIVE;
> > +
> > + for (i = 1; i < ncontrols; i++)
> > + if (controls[i]) {
> > + controls[i]->is_volatile = set_volatile;
> > + controls[i]->flags |= flag;
> > + }
> > +}
> > +EXPORT_SYMBOL(v4l2_ctrl_auto_cluster);
> > +
> > /* Activate/deactivate a control. */
> > void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active)
> > {
> > @@ -1595,7 +1636,7 @@ int v4l2_g_ext_ctrls(struct v4l2_ctrl_handler *hdl, struct v4l2_ext_controls *cs
> > ctrl_is_volatile);
> >
> > /* g_volatile_ctrl will update the new control values */
> > - if (has_volatiles) {
> > + if (has_volatiles && !is_cur_manual(master)) {
> > for (j = 0; j < master->ncontrols; j++)
> > cur_to_new(master->cluster[j]);
> > ret = call_op(master, g_volatile_ctrl);
> > @@ -1633,7 +1674,7 @@ static int get_ctrl(struct v4l2_ctrl *ctrl, s32 *val)
> >
> > v4l2_ctrl_lock(master);
> > /* g_volatile_ctrl will update the current control values */
> > - if (ctrl->is_volatile) {
> > + if (ctrl->is_volatile && !is_cur_manual(master)) {
> > for (i = 0; i < master->ncontrols; i++)
> > cur_to_new(master->cluster[i]);
> > ret = call_op(master, g_volatile_ctrl);
> > @@ -1678,6 +1719,7 @@ EXPORT_SYMBOL(v4l2_ctrl_g_ctrl);
> > Must be called with ctrl->handler->lock held. */
> > static int try_or_set_control_cluster(struct v4l2_ctrl *master, bool set)
> > {
> > + bool update_flag;
> > bool try = !set;
> > int ret = 0;
> > int i;
> > @@ -1717,14 +1759,17 @@ static int try_or_set_control_cluster(struct v4l2_ctrl *master, bool set)
> > ret = call_op(master, try_ctrl);
> >
> > /* Don't set if there is no change */
> > - if (!ret && set && cluster_changed(master)) {
> > - ret = call_op(master, s_ctrl);
> > - /* If OK, then make the new values permanent. */
> > - if (!ret)
> > - for (i = 0; i < master->ncontrols; i++)
> > - new_to_cur(master->cluster[i]);
> > - }
> > - return ret;
> > + if (ret || !set || !cluster_changed(master))
> > + return ret;
> > + ret = call_op(master, s_ctrl);
> > + /* If OK, then make the new values permanent. */
> > + if (ret)
> > + return ret;
> > +
> > + update_flag = is_cur_manual(master) != is_new_manual(master);
> > + for (i = 0; i < master->ncontrols; i++)
> > + new_to_cur(master->cluster[i], update_flag && i > 0);
> > + return 0;
> > }
> >
> > /* Try or set controls. */
> > diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
> > index 97d0638..56323e3 100644
> > --- a/include/media/v4l2-ctrls.h
> > +++ b/include/media/v4l2-ctrls.h
> > @@ -65,6 +65,15 @@ struct v4l2_ctrl_ops {
> > * control's current value cannot be cached and needs to be
> > * retrieved through the g_volatile_ctrl op. Drivers can set
> > * this flag.
> > + * @is_auto: If set, then this control selects whether the other cluster
> > + * members are in 'automatic' mode or 'manual' mode. This is
> > + * used for autogain/gain type clusters. Drivers should never
> > + * set this flag directly.
> > + * @manual_mode_value: If the is_auto flag is set, then this is the value
> > + * of the auto control that determines if that control is in
> > + * manual mode. So if the value of the auto control equals this
> > + * value, then the whole cluster is in manual mode. Drivers should
> > + * never set this flag directly.
> > * @ops: The control ops.
> > * @id: The control ID.
> > * @name: The control name.
> > @@ -105,6 +114,8 @@ struct v4l2_ctrl {
> > unsigned int is_new:1;
> > unsigned int is_private:1;
> > unsigned int is_volatile:1;
> > + unsigned int is_auto:1;
> > + unsigned int manual_mode_value:5;
>
> Why are you using 5 bits for it? It seems too arbitrary to limit it to 32, especially
> since I failed to see any rationale for that in the documentation.
This value is for a boolean or menu control. The menu control is currently
limited to 32 values, hence the 5 bits. However, it is probably better to
make it 8 bits and add a check above for whether the manual_mode_value >
ctrl->maximum (or < ctrl->minimum while I'm at it).
That's a lot more general.
> >
> > const struct v4l2_ctrl_ops *ops;
> > u32 id;
> > @@ -363,6 +374,40 @@ int v4l2_ctrl_add_handler(struct v4l2_ctrl_handler *hdl,
> > void v4l2_ctrl_cluster(unsigned ncontrols, struct v4l2_ctrl **controls);
> >
> >
> > +/** v4l2_ctrl_auto_cluster() - Mark all controls in the cluster as belonging to
> > + * that cluster and set it up for autofoo/foo-type handling.
> > + * @ncontrols: The number of controls in this cluster.
> > + * @controls: The cluster control array of size @ncontrols. The first control
> > + * must be the 'auto' control (e.g. autogain, autoexposure, etc.)
> > + * @manual_val: The value for the first control in the cluster that equals the
> > + * manual setting.
> > + * @set_volatile: If true, then all controls except the first auto control will
> > + * have is_volatile set to true. If false, then is_volatile will not
> > + * be touched.
> > + *
> > + * Use for control groups where one control selects some automatic feature and
> > + * the other controls are only active whenever the automatic feature is turned
> > + * off (manual mode). Typical examples: autogain vs gain, auto-whitebalance vs
> > + * red and blue balance, etc.
> > + *
> > + * The behavior of such controls is as follows:
> > + *
> > + * When the autofoo control is set to automatic, then any manual controls
> > + * are set to inactive and any reads will call g_volatile_ctrl (if the control
> > + * was marked volatile).
> > + *
> > + * When the autofoo control is set to manual, then any manual controls will
> > + * be marked active, and any reads will just return the current value without
> > + * going through g_volatile_ctrl.
> > + *
> > + * In addition, this function will set the V4L2_CTRL_FLAG_UPDATE flag
> > + * on the autofoo control and V4L2_CTRL_FLAG_INACTIVE on the foo control(s)
> > + * if autofoo is in auto mode.
> > + */
> > +void v4l2_ctrl_auto_cluster(unsigned ncontrols, struct v4l2_ctrl **controls,
> > + u8 manual_val, bool set_volatile);
>
> If you're limiting it to 5 bits, why are you allowing 8 bits here?
There is no u5?
Anyway, I'll change it to 8 bits.
Regards,
Hans
>
> > +
> > +
> > /** v4l2_ctrl_find() - Find a control with the given ID.
> > * @hdl: The control handler.
> > * @id: The control ID to find.
>
>
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