[media] uvcvideo: Add UVCIOC_CTRL_QUERY ioctl

This ioctl extends UVCIOC_CTRL_GET/SET by not only allowing to get/set
XU controls but to also send arbitrary UVC commands to XU controls,
namely GET_CUR, SET_CUR, GET_MIN, GET_MAX, GET_RES, GET_LEN, GET_INFO
and GET_DEF. This is required for applications to work with XU controls,
so that they can properly query the size and allocate the necessary
buffers.

Signed-off-by: Martin Rubli <martin_rubli@logitech.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 11 insertions, 2 deletions

diff --git a/drivers/media/video/uvc/uvcvideo.h b/drivers/media/video/uvc/uvcvideo.h
index 45f01e7e13d2..a3f4d308358a 100644
--- a/drivers/media/video/uvc/uvcvideo.h
+++ b/drivers/media/video/uvc/uvcvideo.h
@@ -57,7 +57,7 @@ struct uvc_xu_control_mapping {
 
         __u8 size;
         __u8 offset;
-        enum v4l2_ctrl_type v4l2_type;
+        __u32 v4l2_type;
         __u32 data_type;
 
         struct uvc_menu_info __user *menu_info;
@@ -73,11 +73,20 @@ struct uvc_xu_control {
         __u8 __user *data;
 };
 
+struct uvc_xu_control_query {
+        __u8 unit;
+        __u8 selector;
+        __u8 query;
+        __u16 size;
+        __u8 __user *data;
+};
+
 #define UVCIOC_CTRL_ADD         _IOW('U', 1, struct uvc_xu_control_info)
 #define UVCIOC_CTRL_MAP_OLD     _IOWR('U', 2, struct uvc_xu_control_mapping_old)
 #define UVCIOC_CTRL_MAP         _IOWR('U', 2, struct uvc_xu_control_mapping)
 #define UVCIOC_CTRL_GET         _IOWR('U', 3, struct uvc_xu_control)
 #define UVCIOC_CTRL_SET         _IOW('U', 4, struct uvc_xu_control)
+#define UVCIOC_CTRL_QUERY       _IOWR('U', 5, struct uvc_xu_control_query)
 
 #ifdef __KERNEL__
 
@@ -638,7 +647,7 @@ extern int uvc_ctrl_set(struct uvc_video_chain *chain,
                 struct v4l2_ext_control *xctrl);
 
 extern int uvc_xu_ctrl_query(struct uvc_video_chain *chain,
-                struct uvc_xu_control *ctrl, int set);
+                struct uvc_xu_control_query *xqry);
 
 /* Utility functions */
 extern void uvc_simplify_fraction(uint32_t *numerator, uint32_t *denominator,