diff options
author | Hans Verkuil <hverkuil@xs4all.nl> | 2011-01-11 12:45:03 -0500 |
---|---|---|
committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-01-19 08:45:32 -0500 |
commit | 2a863793beaa0fc9ee7aeb87efe85544a6b129c0 (patch) | |
tree | 9316b12b95a707eb5541db2e24d6033d9b0e2805 /Documentation/video4linux | |
parent | 45f6f84af3ae9db19f39bc5d0976d626b0ef626e (diff) |
[media] v4l2-ctrls: v4l2_ctrl_handler_setup must set is_new to 1
Renamed has_new to is_new.
Drivers can use the is_new field to determine if a new value was specified
for a control. The v4l2_ctrl_handler_setup() must always set this to 1 since
the setup has to force a full update of all controls.
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/video4linux')
-rw-r--r-- | Documentation/video4linux/v4l2-controls.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt index 8773778d23fc..881e7f44491b 100644 --- a/Documentation/video4linux/v4l2-controls.txt +++ b/Documentation/video4linux/v4l2-controls.txt | |||
@@ -285,6 +285,9 @@ implement g_volatile_ctrl like this: | |||
285 | The 'new value' union is not used in g_volatile_ctrl. In general controls | 285 | The 'new value' union is not used in g_volatile_ctrl. In general controls |
286 | that need to implement g_volatile_ctrl are read-only controls. | 286 | that need to implement g_volatile_ctrl are read-only controls. |
287 | 287 | ||
288 | Note that if one or more controls in a control cluster are marked as volatile, | ||
289 | then all the controls in the cluster are seen as volatile. | ||
290 | |||
288 | To mark a control as volatile you have to set the is_volatile flag: | 291 | To mark a control as volatile you have to set the is_volatile flag: |
289 | 292 | ||
290 | ctrl = v4l2_ctrl_new_std(&sd->ctrl_handler, ...); | 293 | 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. | |||
462 | Obviously, all controls in the cluster array must be initialized to either | 465 | Obviously, all controls in the cluster array must be initialized to either |
463 | a valid control or to NULL. | 466 | a valid control or to NULL. |
464 | 467 | ||
468 | In rare cases you might want to know which controls of a cluster actually | ||
469 | were set explicitly by the user. For this you can check the 'is_new' flag of | ||
470 | each control. For example, in the case of a volume/mute cluster the 'is_new' | ||
471 | flag of the mute control would be set if the user called VIDIOC_S_CTRL for | ||
472 | mute only. If the user would call VIDIOC_S_EXT_CTRLS for both mute and volume | ||
473 | controls, then the 'is_new' flag would be 1 for both controls. | ||
474 | |||
475 | The 'is_new' flag is always 1 when called from v4l2_ctrl_handler_setup(). | ||
476 | |||
465 | 477 | ||
466 | VIDIOC_LOG_STATUS Support | 478 | VIDIOC_LOG_STATUS Support |
467 | ========================= | 479 | ========================= |