From: Lad, Prabhakar <prabhakar.lad@xxxxxx>
Add a helper function to modify the menu, max and default value
to set.
Signed-off-by: Lad, Prabhakar <prabhakar.lad@xxxxxx>
Signed-off-by: Manjunath Hadli <manjunath.hadli@xxxxxx>
Cc: Hans Verkuil <hans.verkuil@xxxxxxxxx>
Cc: Sakari Ailus <sakari.ailus@xxxxxx>
Cc: Sylwester Nawrocki <s.nawrocki@xxxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx>
Cc: Hans de Goede <hdegoede@xxxxxxxxxx>
Cc: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
Cc: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
Cc: Rob Landley <rob@xxxxxxxxxxx>
---
Changes for v3:
1: Fixed style/grammer issues as pointed by Hans.
Thanks Hans for providing the description.
Changes for v2:
1: Fixed review comments from Hans, to have return type as
void, add WARN_ON() for fail conditions, allow this fucntion
to modify the menu of custom controls.
Documentation/video4linux/v4l2-controls.txt | 29 +++++++++++++++++++++++++++
drivers/media/v4l2-core/v4l2-ctrls.c | 17 +++++++++++++++
include/media/v4l2-ctrls.h | 11 ++++++++++
3 files changed, 57 insertions(+), 0 deletions(-)
diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index 43da22b..01d0a82 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -367,6 +367,35 @@ it to 0 means that all menu items are supported.
You set this mask either through the v4l2_ctrl_config struct for a custom
control, or by calling v4l2_ctrl_new_std_menu().
+There are situations where menu items may be device specific. In such cases the
+framework provides a helper function to change the menu:
+
+void v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl, const char * const *qmenu,
+ s32 max, u32 menu_skip_mask, s32 def);
+
+A good example is the test pattern control for capture/display/sensors devices
+that have the capability to generate test patterns. These test patterns are
+hardware specific, so the contents of the menu will vary from device to device.
+
+This helper function is used to modify the menu, max, mask and the default
+value of the control.
+
+Example:
+
+ static const char * const test_pattern[] = {
+ "Disabled",
+ "Vertical Bars",
+ "Solid Black",
+ "Solid White",
+ NULL,
+ };
+ struct v4l2_ctrl *test_pattern_ctrl =
+ v4l2_ctrl_new_std_menu(&foo->ctrl_handler, &foo_ctrl_ops,
+ V4L2_CID_TEST_PATTERN, V4L2_TEST_PATTERN_DISABLED, 0,
+ V4L2_TEST_PATTERN_DISABLED);
+
+ v4l2_ctrl_modify_menu(test_pattern_ctrl, test_pattern, 3, 0,
+ V4L2_TEST_PATTERN_DISABLED);
Custom Controls
===============
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index d731422..d89b460 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -2666,3 +2666,20 @@ unsigned int v4l2_ctrl_poll(struct file *file, struct poll_table_struct *wait)
return 0;
}
EXPORT_SYMBOL(v4l2_ctrl_poll);
+
+/* Helper function for modifying the menu */
+void v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl, const char * const *qmenu,
+ s32 max, u32 menu_skip_mask, s32 def)
+{
+ if (WARN_ON(ctrl->type != V4L2_CTRL_TYPE_MENU || qmenu == NULL))
+ return;
+
+ if (WARN_ON(def < 0 || def > max))
+ return;
+
+ ctrl->qmenu = qmenu;
+ ctrl->maximum = max;
+ ctrl->menu_skip_mask = menu_skip_mask;
+ ctrl->cur.val = ctrl->val = ctrl->default_value = def;
+}
+EXPORT_SYMBOL(v4l2_ctrl_modify_menu);
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 776605f..5303489 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -488,6 +488,17 @@ static inline void v4l2_ctrl_unlock(struct v4l2_ctrl *ctrl)
mutex_unlock(ctrl->handler->lock);
}
+/**
+ * v4l2_ctrl_modify_menu() - This function is used to modify the menu.
+ * @ctrl: The control whose menu should be modified.
+ * @qmenu: The new menu.
+ * @max: Maximum value of the control.
+ * @menu_skip_mask: The control's skip mask for menu controls.
+ * @def: The default value for control to be set.
+ */
+void v4l2_ctrl_modify_menu(struct v4l2_ctrl *ctrl, const char * const *qmenu,
+ s32 max, u32 menu_skip_mask, s32 def);
+
/** v4l2_ctrl_g_ctrl() - Helper function to get the control's value from within a driver.
* @ctrl: The control.
*
--
1.7.0.4
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