[PATCH v2 1/5] Add the `REL_WHEEL_HI_RES` event code

From: Harry Cutts
Date: Thu Aug 30 2018 - 17:56:53 EST

This event code represents scroll reports from high-resolution wheels,
and will be used by future patches in this series. See the linux-input
"Reporting high-resolution scroll events" thread [0] for more details.

[0]: https://www.spinics.net/lists/linux-input/msg57380.html

Signed-off-by: Harry Cutts <hcutts@xxxxxxxxxxxx>

Changes in v2: None

Documentation/input/event-codes.rst | 11 ++++++++++-
include/uapi/linux/input-event-codes.h | 1 +
2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/Documentation/input/event-codes.rst b/Documentation/input/event-codes.rst
index a8c0873beb95..cef220c176a4 100644
--- a/Documentation/input/event-codes.rst
+++ b/Documentation/input/event-codes.rst
@@ -190,7 +190,16 @@ A few EV_REL codes have special meanings:

- These codes are used for vertical and horizontal scroll wheels,
- respectively.
+ respectively. The value is the number of "notches" moved on the wheel, the
+ physical size of which varies by device. For high-resolution wheels (which
+ report multiple events for each notch of movement, or do not have notches)
+ this may be an approximation based on the high-resolution scroll events.
+ - If a vertical scroll wheel supports high-resolution scrolling, this code
+ will be emitted in addition to REL_WHEEL. The value is the (approximate)
+ distance travelled by the user's finger, in microns.

diff --git a/include/uapi/linux/input-event-codes.h b/include/uapi/linux/input-event-codes.h
index 53fbae27b280..dad8d3890a3a 100644
--- a/include/uapi/linux/input-event-codes.h
+++ b/include/uapi/linux/input-event-codes.h
@@ -708,6 +708,7 @@
#define REL_DIAL 0x07
#define REL_WHEEL 0x08
#define REL_MISC 0x09
+#define REL_WHEEL_HI_RES 0x0a
#define REL_MAX 0x0f
#define REL_CNT (REL_MAX+1)