HID: uhid: forward open/close events to user-space

HID core notifies us with *_open/*_close callbacks when there is an actual
user of our device. We forward these to user-space so they can react on
this. This allows user-space to skip I/O unless they receive an OPEN
event. When they receive a CLOSE event they can stop I/O again to save
energy.

Signed-off-by: David Herrmann <dh.herrmann@googlemail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

2 files changed, 8 insertions, 1 deletions

diff --git a/drivers/hid/uhid.c b/drivers/hid/uhid.c
index 2e7f3a023975..0226ba3f5307 100644
--- a/drivers/hid/uhid.c
+++ b/drivers/hid/uhid.c
@@ -97,11 +97,16 @@ static void uhid_hid_stop(struct hid_device *hid)
 
 static int uhid_hid_open(struct hid_device *hid)
 {
-        return 0;
+        struct uhid_device *uhid = hid->driver_data;
+
+        return uhid_queue_event(uhid, UHID_OPEN);
 }
 
 static void uhid_hid_close(struct hid_device *hid)
 {
+        struct uhid_device *uhid = hid->driver_data;
+
+        uhid_queue_event(uhid, UHID_CLOSE);
 }
 
 static int uhid_hid_input(struct input_dev *input, unsigned int type,
diff --git a/include/linux/uhid.h b/include/linux/uhid.h
index f8ce6f7571d8..351650b7a0f6 100644
--- a/include/linux/uhid.h
+++ b/include/linux/uhid.h
@@ -27,6 +27,8 @@ enum uhid_event_type {
         UHID_DESTROY,
         UHID_START,
         UHID_STOP,
+        UHID_OPEN,
+        UHID_CLOSE,
         UHID_INPUT,
 };