[media] V4L: Add helper function for standard integer menu controls

This patch adds v4l2_ctrl_new_int_menu() helper function which can be used
in drivers for creating standard integer menu control with driver-specific
menu item list. It is similar to v4l2_ctrl_new_std_menu(), except it doesn't
have a mask parameter and an additional qmenu parameter allows passing
an array of signed 64-bit integers as the menu item list.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Sakari Ailus <sakari.ailus@iki.fi>
Tested-by: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 59 insertions, 0 deletions

diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index e2492a9d1027..43da22b89728 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -130,8 +130,18 @@ Menu controls are added by calling v4l2_ctrl_new_std_menu:
                         const struct v4l2_ctrl_ops *ops,
                         u32 id, s32 max, s32 skip_mask, s32 def);
 
+Or alternatively for integer menu controls, by calling v4l2_ctrl_new_int_menu:
+
+        struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
+                        const struct v4l2_ctrl_ops *ops,
+                        u32 id, s32 max, s32 def, const s64 *qmenu_int);
+
 These functions are typically called right after the v4l2_ctrl_handler_init:
 
+        static const s64 exp_bias_qmenu[] = {
+               -2, -1, 0, 1, 2
+        };
+
         v4l2_ctrl_handler_init(&foo->ctrl_handler, nr_of_controls);
         v4l2_ctrl_new_std(&foo->ctrl_handler, &foo_ctrl_ops,
                         V4L2_CID_BRIGHTNESS, 0, 255, 1, 128);
@@ -141,6 +151,11 @@ These functions are typically called right after the v4l2_ctrl_handler_init:
                         V4L2_CID_POWER_LINE_FREQUENCY,
                         V4L2_CID_POWER_LINE_FREQUENCY_60HZ, 0,
                         V4L2_CID_POWER_LINE_FREQUENCY_DISABLED);
+        v4l2_ctrl_new_int_menu(&foo->ctrl_handler, &foo_ctrl_ops,
+                        V4L2_CID_EXPOSURE_BIAS,
+                        ARRAY_SIZE(exp_bias_qmenu) - 1,
+                        ARRAY_SIZE(exp_bias_qmenu) / 2 - 1,
+                        exp_bias_qmenu);
         ...
         if (foo->ctrl_handler.error) {
                 int err = foo->ctrl_handler.error;
@@ -164,6 +179,12 @@ controls. There is no min argument since that is always 0 for menu controls,
 and instead of a step there is a skip_mask argument: if bit X is 1, then menu
 item X is skipped.
 
+The v4l2_ctrl_new_int_menu function creates a new standard integer menu
+control with driver-specific items in the menu. It differs from
+v4l2_ctrl_new_std_menu in that it doesn't have the mask argument and takes
+as the last argument an array of signed 64-bit integers that form an exact
+menu item list.
+
 Note that if something fails, the function will return NULL or an error and
 set ctrl_handler->error to the error code. If ctrl_handler->error was already
 set, then it will just return and do nothing. This is also true for
diff --git a/drivers/media/video/v4l2-ctrls.c b/drivers/media/video/v4l2-ctrls.c
index 9bd8a92419e1..fdcb9e21d9d3 100644
--- a/drivers/media/video/v4l2-ctrls.c
+++ b/drivers/media/video/v4l2-ctrls.c
@@ -1544,6 +1544,27 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
 }
 EXPORT_SYMBOL(v4l2_ctrl_new_std_menu);
 
+/* Helper function for standard integer menu controls */
+struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
+                        const struct v4l2_ctrl_ops *ops,
+                        u32 id, s32 max, s32 def, const s64 *qmenu_int)
+{
+        const char *name;
+        enum v4l2_ctrl_type type;
+        s32 min;
+        s32 step;
+        u32 flags;
+
+        v4l2_ctrl_fill(id, &name, &type, &min, &max, &step, &def, &flags);
+        if (type != V4L2_CTRL_TYPE_INTEGER_MENU) {
+                handler_set_err(hdl, -EINVAL);
+                return NULL;
+        }
+        return v4l2_ctrl_new(hdl, ops, id, name, type,
+                             0, max, 0, def, flags, NULL, qmenu_int, NULL);
+}
+EXPORT_SYMBOL(v4l2_ctrl_new_int_menu);
+
 /* Add a control from another handler to this handler */
 struct v4l2_ctrl *v4l2_ctrl_add_ctrl(struct v4l2_ctrl_handler *hdl,
                                           struct v4l2_ctrl *ctrl)
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 5edd64daa425..776605f1cbe2 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -351,6 +351,23 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
                         const struct v4l2_ctrl_ops *ops,
                         u32 id, s32 max, s32 mask, s32 def);
 
+/** v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
+  * @hdl:       The control handler.
+  * @ops:       The control ops.
+  * @id:        The control ID.
+  * @max:       The control's maximum value.
+  * @def:       The control's default value.
+  * @qmenu_int: The control's menu entries.
+  *
+  * Same as v4l2_ctrl_new_std_menu(), but @mask is set to 0 and it additionaly
+  * takes as an argument an array of integers determining the menu items.
+  *
+  * If @id refers to a non-integer-menu control, then this function will return NULL.
+  */
+struct v4l2_ctrl *v4l2_ctrl_new_int_menu(struct v4l2_ctrl_handler *hdl,
+                        const struct v4l2_ctrl_ops *ops,
+                        u32 id, s32 max, s32 def, const s64 *qmenu_int);
+
 /** v4l2_ctrl_add_ctrl() - Add a control from another handler to this handler.
   * @hdl:       The control handler.
   * @ctrl:      The control to add.