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Input: add detailed multi-touch finger data report protocol

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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.

The driver sends a SYN_MT_REPORT event via the input_mt_sync() function
when a complete 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. In addition, all finger data must bypass input filtering,
since subsequent events of the same type refer to different fingers.

A set of ABS_MT events with the desired properties are defined. The
events are divided into categories, to allow for partial implementation.
The minimum set consists of ABS_MT_TOUCH_MAJOR, ABS_MT_POSITION_X and
ABS_MT_POSITION_Y, which allows for multiple fingers to be tracked.
If the device supports it, the ABS_MT_WIDTH_MAJOR may be used to provide
the size of the approaching finger. Anisotropy and direction may be
specified with ABS_MT_TOUCH_MINOR, ABS_MT_WIDTH_MINOR and
ABS_MT_ORIENTATION. Devices with more granular information may specify
general shapes as blobs, i.e., as a sequence of rectangular shapes
grouped together by a ABS_MT_BLOB_ID. Finally, the ABS_MT_TOOL_TYPE
may be used to specify whether the touching tool is a finger or a pen.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Henrik Rydberg
2009-04-28 07:47:33 -07:00
committed by Dmitry Torokhov
parent 61994a61bc
commit 5e5ee686e3
2 changed files with 36 additions and 0 deletions
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13
drivers/input/input.c
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@@ -33,6 +33,15 @@ MODULE_LICENSE("GPL");
* EV_ABS events which should not be cached are listed here.
*/
static unsigned int input_abs_bypass_init_data[] __initdata = {
ABS_MT_TOUCH_MAJOR,
ABS_MT_TOUCH_MINOR,
ABS_MT_WIDTH_MAJOR,
ABS_MT_WIDTH_MINOR,
ABS_MT_ORIENTATION,
ABS_MT_POSITION_X,
ABS_MT_POSITION_Y,
ABS_MT_TOOL_TYPE,
ABS_MT_BLOB_ID,
0
};
static unsigned long input_abs_bypass[BITS_TO_LONGS(ABS_CNT)];
@@ -169,6 +178,10 @@ static void input_handle_event(struct input_dev *dev,
disposition = INPUT_PASS_TO_HANDLERS;
}
break;
case SYN_MT_REPORT:
dev->sync = 0;
disposition = INPUT_PASS_TO_HANDLERS;
break;
}
break;