[PATCH] input: Add a detailed multi-touch finger data report protocol

Henrik Rydberg
2008-11-07T11:15:53Z

In order to utilize the full power of the new multi-touch devices, a
way to report detailed finger data to user space is needed. This patch
adds a multi-touch (MT) protocol which allows drivers to report details
for an arbitrary number of fingers.

BTN_MT_REPORT_PACKET

The driver presses this button to indicate the start of a packet of
finger data. The button is released after the whole packet has been
reported.

BTN_MT_REPORT_FINGER

The driver presses this button to indicate the start of a new
finger. The button is released when the finger has been reported.

In order to stay compatible with existing applications, the data
reported in a finger packet must not be recognized as single-touch
events. Therefore, a specific set of ABS_MT events is used instead.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
---
include/linux/input.h | 12 ++++++++++++
1 files changed, 12 insertions(+), 0 deletions(-)

diff --git a/include/linux/input.h b/include/linux/input.h
index b86fb55..c82dd42 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -590,6 +590,9 @@ struct input_absinfo {
#define KEY_NUMERIC_STAR 0x20a
#define KEY_NUMERIC_POUND 0x20b

+#define BTN_MT_REPORT_PACKET 0x210 /* report multitouch packet data */
+#define BTN_MT_REPORT_FINGER 0x211 /* report multitouch finger data */
+
/* We avoid low common keys in module aliases so they don't get huge. */
#define KEY_MIN_INTERESTING KEY_MUTE
#define KEY_MAX 0x2ff
@@ -642,6 +645,15 @@ struct input_absinfo {
#define ABS_TOOL_WIDTH 0x1c
#define ABS_VOLUME 0x20
#define ABS_MISC 0x28
+#define ABS_MT_TOUCH 0x30 /* Diameter of touching circle */
+#define ABS_MT_TOUCH_MAJOR 0x30 /* Major axis of touching ellipse */
+#define ABS_MT_TOUCH_MINOR 0x31 /* Minor axis of touching ellipse */
+#define ABS_MT_WIDTH 0x32 /* Diameter of approaching circle */
+#define ABS_MT_WIDTH_MAJOR 0x32 /* Major axis of approaching ellipse */
+#define ABS_MT_WIDTH_MINOR 0x33 /* Minor axis of approaching ellipse */
+#define ABS_MT_ORIENTATION 0x34 /* Ellipse orientation */
+#define ABS_MT_POSITION_X 0x35 /* Center X ellipse position */
+#define ABS_MT_POSITION_Y 0x36 /* Center Y ellipse position */
#define ABS_MAX 0x3f
#define ABS_CNT (ABS_MAX+1)

--
1.5.6.3