diff options
| -rw-r--r-- | Documentation/video4linux/v4l2-controls.txt | 12 | ||||
| -rw-r--r-- | drivers/media/video/v4l2-ctrls.c | 24 | ||||
| -rw-r--r-- | include/media/v4l2-ctrls.h | 6 |
3 files changed, 30 insertions, 12 deletions
diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt index 8773778d..881e7f4 100644 --- a/Documentation/video4linux/v4l2-controls.txt +++ b/Documentation/video4linux/v4l2-controls.txt @@ -285,6 +285,9 @@ implement g_volatile_ctrl like this: The 'new value' union is not used in g_volatile_ctrl. In general controls that need to implement g_volatile_ctrl are read-only controls. +Note that if one or more controls in a control cluster are marked as volatile, +then all the controls in the cluster are seen as volatile. + To mark a control as volatile you have to set the is_volatile flag: ctrl = v4l2_ctrl_new_std(&sd->ctrl_handler, ...); @@ -462,6 +465,15 @@ pointer to the v4l2_ctrl_ops struct that is used for that cluster. Obviously, all controls in the cluster array must be initialized to either a valid control or to NULL. +In rare cases you might want to know which controls of a cluster actually +were set explicitly by the user. For this you can check the 'is_new' flag of +each control. For example, in the case of a volume/mute cluster the 'is_new' +flag of the mute control would be set if the user called VIDIOC_S_CTRL for +mute only. If the user would call VIDIOC_S_EXT_CTRLS for both mute and volume +controls, then the 'is_new' flag would be 1 for both controls. + +The 'is_new' flag is always 1 when called from v4l2_ctrl_handler_setup(). + VIDIOC_LOG_STATUS Support ========================= diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c index 8f81efc..0d1a3d8 100644 --- a/drivers/media/video/v4l2-ctrls.c +++ b/drivers/media/video/v4l2-ctrls.c @@ -569,7 +569,7 @@ static int user_to_new(struct v4l2_ext_control *c, int ret; u32 size; - ctrl->has_new = 1; + ctrl->is_new = 1; switch (ctrl->type) { case V4L2_CTRL_TYPE_INTEGER64: ctrl->val64 = c->value64; @@ -1280,8 +1280,12 @@ int v4l2_ctrl_handler_setup(struct v4l2_ctrl_handler *hdl) if (ctrl->done) continue; - for (i = 0; i < master->ncontrols; i++) - cur_to_new(master->cluster[i]); + for (i = 0; i < master->ncontrols; i++) { + if (master->cluster[i]) { + cur_to_new(master->cluster[i]); + master->cluster[i]->is_new = 1; + } + } /* Skip button controls and read-only controls. */ if (ctrl->type == V4L2_CTRL_TYPE_BUTTON || @@ -1645,7 +1649,7 @@ static int try_or_set_control_cluster(struct v4l2_ctrl *master, bool set) if (ctrl == NULL) continue; - if (ctrl->has_new) { + if (ctrl->is_new) { /* Double check this: it may have changed since the last check in try_or_set_ext_ctrls(). */ if (set && (ctrl->flags & V4L2_CTRL_FLAG_GRABBED)) @@ -1719,13 +1723,13 @@ static int try_or_set_ext_ctrls(struct v4l2_ctrl_handler *hdl, v4l2_ctrl_lock(ctrl); - /* Reset the 'has_new' flags of the cluster */ + /* Reset the 'is_new' flags of the cluster */ for (j = 0; j < master->ncontrols; j++) if (master->cluster[j]) - master->cluster[j]->has_new = 0; + master->cluster[j]->is_new = 0; /* Copy the new caller-supplied control values. - user_to_new() sets 'has_new' to 1. */ + user_to_new() sets 'is_new' to 1. */ ret = cluster_walk(i, cs, helpers, user_to_new); if (!ret) @@ -1822,13 +1826,13 @@ static int set_ctrl(struct v4l2_ctrl *ctrl, s32 *val) v4l2_ctrl_lock(ctrl); - /* Reset the 'has_new' flags of the cluster */ + /* Reset the 'is_new' flags of the cluster */ for (i = 0; i < master->ncontrols; i++) if (master->cluster[i]) - master->cluster[i]->has_new = 0; + master->cluster[i]->is_new = 0; ctrl->val = *val; - ctrl->has_new = 1; + ctrl->is_new = 1; ret = try_or_set_control_cluster(master, false); if (!ret) ret = try_or_set_control_cluster(master, true); diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h index d69ab4a..fcc9a0c 100644 --- a/include/media/v4l2-ctrls.h +++ b/include/media/v4l2-ctrls.h @@ -53,8 +53,10 @@ struct v4l2_ctrl_ops { * @handler: The handler that owns the control. * @cluster: Point to start of cluster array. * @ncontrols: Number of controls in cluster array. - * @has_new: Internal flag: set when there is a valid new value. * @done: Internal flag: set for each processed control. + * @is_new: Set when the user specified a new value for this control. It + * is also set when called from v4l2_ctrl_handler_setup. Drivers + * should never set this flag. * @is_private: If set, then this control is private to its handler and it * will not be added to any other handlers. Drivers can set * this flag. @@ -97,9 +99,9 @@ struct v4l2_ctrl { struct v4l2_ctrl_handler *handler; struct v4l2_ctrl **cluster; unsigned ncontrols; - unsigned int has_new:1; unsigned int done:1; + unsigned int is_new:1; unsigned int is_private:1; unsigned int is_volatile:1; |
