diff options
| author | Hans Verkuil <hans.verkuil@cisco.com> | 2012-09-07 04:46:39 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2013-01-05 00:49:54 -0200 |
| commit | 8ac7a9493a4380a8a886fbfe311ab00bc424ca0f (patch) | |
| tree | 25f60268aad8cf9f45c44b1ef7e8a2f30e506952 /include/media | |
| parent | 20deebfe17b20ded00ba404adbcd014eb2b024c1 (diff) | |
[media] v4l2-ctrls: add a notify callback
Sometimes platform/bridge drivers need to be notified when a control from
a sub-device changes value. In order to support this a notify callback was
added.
[dheitmueller@kernellabs.com: fix merge conflict in v4l2-ctrls.c]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'include/media')
| -rw-r--r-- | include/media/v4l2-ctrls.h | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h index 96509119f28..c4cc0413607 100644 --- a/include/media/v4l2-ctrls.h +++ b/include/media/v4l2-ctrls.h @@ -53,6 +53,8 @@ struct v4l2_ctrl_ops { int (*s_ctrl)(struct v4l2_ctrl *ctrl); }; +typedef void (*v4l2_ctrl_notify_fnc)(struct v4l2_ctrl *ctrl, void *priv); + /** struct v4l2_ctrl - The control structure. * @node: The list node. * @ev_subs: The list of control event subscriptions. @@ -72,6 +74,8 @@ struct v4l2_ctrl_ops { * set this flag directly. * @has_volatiles: If set, then one or more members of the cluster are volatile. * Drivers should never touch this flag. + * @call_notify: If set, then call the handler's notify function whenever the + * control's value changes. * @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 @@ -119,6 +123,7 @@ struct v4l2_ctrl { unsigned int is_private:1; unsigned int is_auto:1; unsigned int has_volatiles:1; + unsigned int call_notify:1; unsigned int manual_mode_value:8; const struct v4l2_ctrl_ops *ops; @@ -177,6 +182,10 @@ struct v4l2_ctrl_ref { * control is needed multiple times, so this is a simple * optimization. * @buckets: Buckets for the hashing. Allows for quick control lookup. + * @notify: A notify callback that is called whenever the control changes value. + * Note that the handler's lock is held when the notify function + * is called! + * @notify_priv: Passed as argument to the v4l2_ctrl notify callback. * @nr_of_buckets: Total number of buckets in the array. * @error: The error code of the first failed control addition. */ @@ -187,6 +196,8 @@ struct v4l2_ctrl_handler { struct list_head ctrl_refs; struct v4l2_ctrl_ref *cached; struct v4l2_ctrl_ref **buckets; + v4l2_ctrl_notify_fnc notify; + void *notify_priv; u16 nr_of_buckets; int error; }; @@ -525,6 +536,20 @@ static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl) mutex_unlock(ctrl->handler->lock); } +/** v4l2_ctrl_notify() - Function to set a notify callback for a control. + * @ctrl: The control. + * @notify: The callback function. + * @priv: The callback private handle, passed as argument to the callback. + * + * This function sets a callback function for the control. If @ctrl is NULL, + * then it will do nothing. If @notify is NULL, then the notify callback will + * be removed. + * + * There can be only one notify. If another already exists, then a WARN_ON + * will be issued and the function will do nothing. + */ +void v4l2_ctrl_notify(struct v4l2_ctrl *ctrl, v4l2_ctrl_notify_fnc notify, void *priv); + /** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver. * @ctrl: The control. * |