drivers: video: introduce "GET" sub-operations

The video_get_ctrl() API permits to retreive a value from a device using
standard CIDs from <zephyr/drivers/video-controls.h>. The CIDs do not come with
a range information, and to know which value to apply to a video driver, knowing
the minimum and maximum value before-hand is required. This prevents building
generic layers that handle any video devices, such as protocols such as USB UVC,
GigE Vision, or anything making use of "zephyr,camera" chosen node.

This commit introduces extra flags added to the CIDs that indicates to the
target device that instead of returning the current value, they should return
the minimum, maximum, or default value instead, with the same type as the
current value.

The GET_CUR operation having a flag of 0x00, this makes all drivers implicitly
support this new API, with an opt-in migration to also support the extra
controls, correctly rejecting the unsupported extra operations by default.

Signed-off-by: Josuah Demangeon <[email protected]>

include/zephyr/drivers/video-controls.h

@@ -42,6 +42,19 @@ extern "C" {
  * @}
  */
 
+/**
+ * @name Control Get operations
+ * @{
+ */
+#define VIDEO_CTRL_GET_CUR		0x00000000	/**< Get the curent value */
+#define VIDEO_CTRL_GET_MIN		0x00001000	/**< Get the minimum value */
+#define VIDEO_CTRL_GET_MAX		0x00002000	/**< Get the maximum value */
+#define VIDEO_CTRL_GET_DEF		0x00003000	/**< Get the default value */
+#define VIDEO_CTRL_GET_MASK		0x0000f000	/**< Mask for get operations */
+/**
+ * @}
+ */
+
 /**
  * @name Generic class control IDs
  * @{