media: docs: v4l2-controls: add links to functions

This section lacks links to functions. Add one to simplify reading.
Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

Documentation/media/kapi/v4l2-controls.rst

@@ -114,7 +114,7 @@ For sub-device drivers:
 
 2) Add controls:
 
-You add non-menu controls by calling v4l2_ctrl_new_std:
+You add non-menu controls by calling :c:func:`v4l2_ctrl_new_std`:
 
 .. code-block:: none
 
@@ -122,7 +122,8 @@ You add non-menu controls by calling v4l2_ctrl_new_std:
 			const struct v4l2_ctrl_ops *ops,
 			u32 id, s32 min, s32 max, u32 step, s32 def);
 
-Menu and integer menu controls are added by calling v4l2_ctrl_new_std_menu:
+Menu and integer menu controls are added by calling
+:c:func:`v4l2_ctrl_new_std_menu`:
 
 .. code-block:: none
 
@@ -131,7 +132,7 @@ Menu and integer menu controls are added by calling v4l2_ctrl_new_std_menu:
 			u32 id, s32 max, s32 skip_mask, s32 def);
 
 Menu controls with a driver specific menu are added by calling
-v4l2_ctrl_new_std_menu_items:
+:c:func:`v4l2_ctrl_new_std_menu_items`:
 
 .. code-block:: none
 
@@ -141,7 +142,7 @@ v4l2_ctrl_new_std_menu_items:
                        s32 skip_mask, s32 def, const char * const *qmenu);
 
 Integer menu controls with a driver specific menu can be added by calling
-v4l2_ctrl_new_int_menu:
+:c:func:`v4l2_ctrl_new_int_menu`:
 
 .. code-block:: none
 
@@ -149,7 +150,8 @@ v4l2_ctrl_new_int_menu:
 			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:
+These functions are typically called right after the
+:c:func:`v4l2_ctrl_handler_init`:
 
 .. code-block:: none
 
@@ -188,33 +190,34 @@ These functions are typically called right after the v4l2_ctrl_handler_init:
 		return err;
 	}
 
-The v4l2_ctrl_new_std function returns the v4l2_ctrl pointer to the new
-control, but if you do not need to access the pointer outside the control ops,
-then there is no need to store it.
-
-The v4l2_ctrl_new_std function will fill in most fields based on the control
-ID except for the min, max, step and default values. These are passed in the
-last four arguments. These values are driver specific while control attributes
-like type, name, flags are all global. The control's current value will be set
-to the default value.
-
-The v4l2_ctrl_new_std_menu function is very similar but it is used for menu
-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.
-
-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.
+The :c:func:`v4l2_ctrl_new_std` function returns the v4l2_ctrl pointer to
+the new control, but if you do not need to access the pointer outside the
+control ops, then there is no need to store it.
+
+The :c:func:`v4l2_ctrl_new_std` function will fill in most fields based on
+the control ID except for the min, max, step and default values. These are
+passed in the last four arguments. These values are driver specific while
+control attributes like type, name, flags are all global. The control's
+current value will be set to the default value.
+
+The :c:func:`v4l2_ctrl_new_std_menu` function is very similar but it is
+used for menu 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 :c:func:`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.
+
+The :c:func:`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