X-Git-Url: http://git.monstr.eu/?a=blobdiff_plain;f=Documentation%2Finput%2Fevent-codes.rst;h=b24b5343f5eb3a5e527f55b0a4dd0ff0095606cd;hb=1b4fd5d38c633344bca57c1dd874c49474c94462;hp=a8c0873beb952e620db9bb2f2df823624ac90650;hpb=1fbb2dc6f0ce95e73b9bd7e8e899089f5cebc99a;p=linux-2.6-microblaze.git

diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst
index a8c0873beb95..b24b5343f5eb 100644
--- a/Documentation/input/event-codes.rst
+++ b/Documentation/input/event-codes.rst
@@ -190,7 +190,26 @@ A few EV_REL codes have special meanings:
 * REL_WHEEL, REL_HWHEEL:
 
   - These codes are used for vertical and horizontal scroll wheels,
-    respectively.
+    respectively. The value is the number of detents moved on the wheel, the
+    physical size of which varies by device. For high-resolution wheels
+    this may be an approximation based on the high-resolution scroll events,
+    see REL_WHEEL_HI_RES. These event codes are legacy codes and
+    REL_WHEEL_HI_RES and REL_HWHEEL_HI_RES should be preferred where
+    available.
+
+* REL_WHEEL_HI_RES, REL_HWHEEL_HI_RES:
+
+  - High-resolution scroll wheel data. The accumulated value 120 represents
+    movement by one detent. For devices that do not provide high-resolution
+    scrolling, the value is always a multiple of 120. For devices with
+    high-resolution scrolling, the value may be a fraction of 120.
+
+    If a vertical scroll wheel supports high-resolution scrolling, this code
+    will be emitted in addition to REL_WHEEL or REL_HWHEEL. The REL_WHEEL
+    and REL_HWHEEL may be an approximation based on the high-resolution
+    scroll events. There is no guarantee that the high-resolution data
+    is a multiple of 120 at the time of an emulated REL_WHEEL or REL_HWHEEL
+    event.
 
 EV_ABS
 ------