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authorSylwester Nawrocki <sylvester.nawrocki@gmail.com>2013-01-19 15:51:55 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2013-02-05 15:04:06 -0200
commit2ccbe779bcdee130ea7f1525670dc9d60318a981 (patch)
treef667acca6ab42a0565b062616b3a6f176508e874 /include/media/v4l2-ctrls.h
parentaf9bb33aa33d4beb5d0ac505d48530a56856f66c (diff)
[media] v4l2-ctrl: Add helper function for the controls range update
This patch adds a helper function that allows to modify range, i.e. minimum, maximum, step and default value of a v4l2 control, after the control has been created and initialized. This is helpful in situations when range of a control depends on user configurable parameters, e.g. camera sensor absolute exposure time depending on an output image resolution and frame rate. v4l2_ctrl_modify_range() function allows to modify range of an INTEGER, BOOL, MENU, INTEGER_MENU and BITMASK type controls. Based on a patch from Hans Verkuil http://patchwork.linuxtv.org/patch/8654. Signed-off-by: Sylwester Nawrocki <sylvester.nawrocki@gmail.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'include/media/v4l2-ctrls.h')
-rw-r--r--include/media/v4l2-ctrls.h20
1 files changed, 20 insertions, 0 deletions
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index c4cc04136074..91125b6f05a5 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -518,6 +518,26 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
*/
void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
+/** v4l2_ctrl_modify_range() - Update the range of a control.
+ * @ctrl: The control to update.
+ * @min: The control's minimum value.
+ * @max: The control's maximum value.
+ * @step: The control's step value
+ * @def: The control's default value.
+ *
+ * Update the range of a control on the fly. This works for control types
+ * INTEGER, BOOLEAN, MENU, INTEGER MENU and BITMASK. For menu controls the
+ * @step value is interpreted as a menu_skip_mask.
+ *
+ * An error is returned if one of the range arguments is invalid for this
+ * control type.
+ *
+ * This function assumes that the control handler is not locked and will
+ * take the lock itself.
+ */
+int v4l2_ctrl_modify_range(struct v4l2_ctrl *ctrl,
+ s32 min, s32 max, u32 step, s32 def);
+
/** v4l2_ctrl_lock() - Helper function to lock the handler
* associated with the control.
* @ctrl: The control to lock.

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