3 files changed, 47 insertions, 7 deletions

diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h
index 8a4c309d2344..baafe2f2e02a 100644
--- a/include/linux/videodev2.h
+++ b/include/linux/videodev2.h
@@ -1791,6 +1791,7 @@ struct v4l2_streamparm {
 #define V4L2_EVENT_ALL                          0
 #define V4L2_EVENT_VSYNC                        1
 #define V4L2_EVENT_EOS                          2
+#define V4L2_EVENT_CTRL                         3
 #define V4L2_EVENT_PRIVATE_START                0x08000000
 
 /* Payload for V4L2_EVENT_VSYNC */
@@ -1799,21 +1800,45 @@ struct v4l2_event_vsync {
         __u8 field;
 } __attribute__ ((packed));
 
+/* Payload for V4L2_EVENT_CTRL */
+#define V4L2_EVENT_CTRL_CH_VALUE                (1 << 0)
+#define V4L2_EVENT_CTRL_CH_FLAGS                (1 << 1)
+
+struct v4l2_event_ctrl {
+        __u32 changes;
+        __u32 type;
+        union {
+                __s32 value;
+                __s64 value64;
+        };
+        __u32 flags;
+        __s32 minimum;
+        __s32 maximum;
+        __s32 step;
+        __s32 default_value;
+};
+
 struct v4l2_event {
         __u32                           type;
         union {
                 struct v4l2_event_vsync vsync;
+                struct v4l2_event_ctrl  ctrl;
                 __u8                    data[64];
         } u;
         __u32                           pending;
         __u32                           sequence;
         struct timespec                 timestamp;
-        __u32                           reserved[9];
+        __u32                           id;
+        __u32                           reserved[8];
 };
 
+#define V4L2_EVENT_SUB_FL_SEND_INITIAL (1 << 0)
+
 struct v4l2_event_subscription {
         __u32                           type;
-        __u32                           reserved[7];
+        __u32                           id;
+        __u32                           flags;
+        __u32                           reserved[5];
 };
 
 /*
diff --git a/include/media/v4l2-ctrls.h b/include/media/v4l2-ctrls.h
index e720f11a56fd..c45bf40e080d 100644
--- a/include/media/v4l2-ctrls.h
+++ b/include/media/v4l2-ctrls.h
@@ -28,9 +28,10 @@
 /* forward references */
 struct v4l2_ctrl_handler;
 struct v4l2_ctrl;
-struct v4l2_fh;
 struct video_device;
 struct v4l2_subdev;
+struct v4l2_event_subscription;
+struct v4l2_fh;
 
 /** struct v4l2_ctrl_ops - The control operations that the driver has to provide.
   * @g_volatile_ctrl: Get a new value for this control. Generally only relevant
@@ -107,6 +108,7 @@ struct v4l2_ctrl_ops {
 struct v4l2_ctrl {
         /* Administrative fields */
         struct list_head node;
+        struct list_head fhs;
         struct v4l2_ctrl_handler *handler;
         struct v4l2_ctrl **cluster;
         unsigned ncontrols;
@@ -180,6 +182,11 @@ struct v4l2_ctrl_handler {
         int error;
 };
 
+struct v4l2_ctrl_fh {
+        struct list_head node;
+        struct v4l2_fh *fh;
+};
+
 /** struct v4l2_ctrl_config - Control configuration structure.
   * @ops:       The control ops.
   * @id:        The control ID.
@@ -425,9 +432,9 @@ struct v4l2_ctrl *v4l2_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id);
   * This sets or clears the V4L2_CTRL_FLAG_INACTIVE flag atomically.
   * Does nothing if @ctrl == NULL.
   * This will usually be called from within the s_ctrl op.
+  * The V4L2_EVENT_CTRL event will be generated afterwards.
   *
-  * This function can be called regardless of whether the control handler
-  * is locked or not.
+  * This function assumes that the control handler is locked.
   */
 void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
 
@@ -437,11 +444,12 @@ void v4l2_ctrl_activate(struct v4l2_ctrl *ctrl, bool active);
   *
   * This sets or clears the V4L2_CTRL_FLAG_GRABBED flag atomically.
   * Does nothing if @ctrl == NULL.
+  * The V4L2_EVENT_CTRL event will be generated afterwards.
   * This will usually be called when starting or stopping streaming in the
   * driver.
   *
-  * This function can be called regardless of whether the control handler
-  * is locked or not.
+  * This function assumes that the control handler is not locked and will
+  * take the lock itself.
   */
 void v4l2_ctrl_grab(struct v4l2_ctrl *ctrl, bool grabbed);
 
@@ -486,6 +494,11 @@ s32 v4l2_ctrl_g_ctrl(struct v4l2_ctrl *ctrl);
   */
 int v4l2_ctrl_s_ctrl(struct v4l2_ctrl *ctrl, s32 val);
 
+void v4l2_ctrl_add_fh(struct v4l2_ctrl_handler *hdl,
+                struct v4l2_ctrl_fh *ctrl_fh,
+                struct v4l2_event_subscription *sub);
+void v4l2_ctrl_del_fh(struct v4l2_ctrl *ctrl, struct v4l2_fh *fh);
+
 /* Helpers for ioctl_ops. If hdl == NULL then they will all return -EINVAL. */
 int v4l2_queryctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_queryctrl *qc);
 int v4l2_querymenu(struct v4l2_ctrl_handler *hdl, struct v4l2_querymenu *qm);
diff --git a/include/media/v4l2-event.h b/include/media/v4l2-event.h
index 3b86177c8cd2..45e9c1e05513 100644
--- a/include/media/v4l2-event.h
+++ b/include/media/v4l2-event.h
@@ -40,6 +40,7 @@ struct v4l2_kevent {
 struct v4l2_subscribed_event {
         struct list_head        list;
         u32                     type;
+        u32                     id;
 };
 
 struct v4l2_events {
@@ -58,6 +59,7 @@ void v4l2_event_free(struct v4l2_fh *fh);
 int v4l2_event_dequeue(struct v4l2_fh *fh, struct v4l2_event *event,
                        int nonblocking);
 void v4l2_event_queue(struct video_device *vdev, const struct v4l2_event *ev);
+void v4l2_event_queue_fh(struct v4l2_fh *fh, const struct v4l2_event *ev);
 int v4l2_event_pending(struct v4l2_fh *fh);
 int v4l2_event_subscribe(struct v4l2_fh *fh,
                          struct v4l2_event_subscription *sub);