[media] media: v4l2-ctrl: add a helper function to add standard control with driver specific menu

Add helper function v4l2_ctrl_new_std_menu_items(), which adds
a standard menu control, with driver specific menu.

Signed-off-by: Lad, Prabhakar <prabhakar.lad@ti.com>
Signed-off-by: Manjunath Hadli <manjunath.hadli@ti.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 77 insertions, 0 deletions

diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index 54270df99d5c..cfe52c798d74 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -136,11 +136,25 @@ Or alternatively for integer menu controls, by calling v4l2_ctrl_new_int_menu:
                         const struct v4l2_ctrl_ops *ops,
                         u32 id, s32 max, s32 def, const s64 *qmenu_int);
 
+Standard menu controls with a driver specific menu are added by calling
+v4l2_ctrl_new_std_menu_items:
+
+        struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(
+                struct v4l2_ctrl_handler *hdl,
+                const struct v4l2_ctrl_ops *ops, u32 id, s32 max,
+                s32 skip_mask, s32 def, const char * const *qmenu);
+
 These functions are typically called right after the v4l2_ctrl_handler_init:
 
         static const s64 exp_bias_qmenu[] = {
                -2, -1, 0, 1, 2
         };
+        static const char * const test_pattern[] = {
+                "Disabled",
+                "Vertical Bars",
+                "Solid Black",
+                "Solid White",
+        };
 
         v4l2_ctrl_handler_init(&foo->ctrl_handler, nr_of_controls);
         v4l2_ctrl_new_std(&foo->ctrl_handler, &foo_ctrl_ops,
@@ -156,6 +170,9 @@ These functions are typically called right after the v4l2_ctrl_handler_init:
                         ARRAY_SIZE(exp_bias_qmenu) - 1,
                         ARRAY_SIZE(exp_bias_qmenu) / 2 - 1,
                         exp_bias_qmenu);
+        v4l2_ctrl_new_std_menu_items(&foo->ctrl_handler, &foo_ctrl_ops,
+                        V4L2_CID_TEST_PATTERN, ARRAY_SIZE(test_pattern) - 1, 0,
+                        0, test_pattern);
         ...
         if (foo->ctrl_handler.error) {
                 int err = foo->ctrl_handler.error;
@@ -185,6 +202,13 @@ 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.
 
+The v4l2_ctrl_new_std_menu_items function is very similar to
+v4l2_ctrl_new_std_menu but takes an extra parameter qmenu, which is the driver
+specific menu for an otherwise standard menu control. A good example for this
+control 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.
+
 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/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index 0bcef2b52cb1..207bcd8dee11 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -1650,6 +1650,36 @@ struct v4l2_ctrl *v4l2_ctrl_new_std_menu(struct v4l2_ctrl_handler *hdl,
 }
 EXPORT_SYMBOL(v4l2_ctrl_new_std_menu);
 
+/* Helper function for standard menu controls with driver defined menu */
+struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
+                        const struct v4l2_ctrl_ops *ops, u32 id, s32 max,
+                        s32 mask, s32 def, const char * const *qmenu)
+{
+        enum v4l2_ctrl_type type;
+        const char *name;
+        u32 flags;
+        s32 step;
+        s32 min;
+
+        /* v4l2_ctrl_new_std_menu_items() should only be called for
+         * standard controls without a standard menu.
+         */
+        if (v4l2_ctrl_get_menu(id)) {
+                handler_set_err(hdl, -EINVAL);
+                return NULL;
+        }
+
+        v4l2_ctrl_fill(id, &name, &type, &min, &max, &step, &def, &flags);
+        if (type != V4L2_CTRL_TYPE_MENU || qmenu == NULL) {
+                handler_set_err(hdl, -EINVAL);
+                return NULL;
+        }
+        return v4l2_ctrl_new(hdl, ops, id, name, type, 0, max, mask, def,
+                             flags, qmenu, NULL, NULL);
+
+}
+EXPORT_SYMBOL(v4l2_ctrl_new_std_menu_items);
+
 /* 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,
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index 801adb466bd2..96509119f28f 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -351,6 +351,29 @@ 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_std_menu_items() - Create a new standard V4L2 menu control
+  * with driver specific menu.
+  * @hdl:       The control handler.
+  * @ops:       The control ops.
+  * @id:        The control ID.
+  * @max:       The control's maximum value.
+  * @mask:      The control's skip mask for menu controls. This makes it
+  *             easy to skip menu items that are not valid. If bit X is set,
+  *             then menu item X is skipped. Of course, this only works for
+  *             menus with <= 32 menu items. There are no menus that come
+  *             close to that number, so this is OK. Should we ever need more,
+  *             then this will have to be extended to a u64 or a bit array.
+  * @def:       The control's default value.
+  * @qmenu:     The new menu.
+  *
+  * Same as v4l2_ctrl_new_std_menu(), but @qmenu will be the driver specific
+  * menu of this control.
+  *
+  */
+struct v4l2_ctrl *v4l2_ctrl_new_std_menu_items(struct v4l2_ctrl_handler *hdl,
+                        const struct v4l2_ctrl_ops *ops, u32 id, s32 max,
+                        s32 mask, s32 def, const char * const *qmenu);
+
 /** v4l2_ctrl_new_int_menu() - Create a new standard V4L2 integer menu control.
   * @hdl:       The control handler.
   * @ops:       The control ops.