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@xxxxxxxxxxx>
---
drivers/input/input.c | 13 +++++++++++++
include/linux/input.h | 27 +++++++++++++++++++++++++++
2 files changed, 40 insertions(+), 0 deletions(-)
diff --git a/drivers/input/input.c b/drivers/input/input.c
index 8b865ba..2c2a95e 100644
--- a/drivers/input/input.c
+++ b/drivers/input/input.c
@@ -33,6 +33,15 @@ MODULE_LICENSE("GPL");
* EV_ABS events which should not be cached are listed here.
*/
static __initdata unsigned int input_abs_bypass_init_data[] = {
+ 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
};
@@ -165,6 +174,10 @@ 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;
diff --git a/include/linux/input.h b/include/linux/input.h
index 53a1f52..bcfebd9 100644
--- a/include/linux/input.h
+++ b/include/linux/input.h
@@ -106,6 +106,7 @@ struct input_absinfo {
#define SYN_REPORT 0
#define SYN_CONFIG 1
+#define SYN_MT_REPORT 2
/*
* Keys and buttons
@@ -646,6 +647,19 @@ 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_MT_TOOL_TYPE 0x37 /* Type of touching device */
+#define ABS_MT_BLOB_ID 0x38 /* Group a set of packets as a blob */
+
#define ABS_MAX 0x3f
#define ABS_CNT (ABS_MAX+1)
@@ -742,6 +756,14 @@ struct input_absinfo {
#define BUS_ATARI 0x1B
/*
+ * MT_TOOL types
+ */
+#define MT_TOOL_FINGER 0
+#define MT_TOOL_PEN 1
+#define MT_TOOL_MAX 9
+#define MT_TOOL_CNT (MT_TOOL_MAX + 1)
+
+/*
* Values describing the status of a force-feedback effect
*/
#define FF_STATUS_STOPPED 0x00
@@ -1310,6 +1332,11 @@ static inline void input_sync(struct input_dev *dev)
input_event(dev, EV_SYN, SYN_REPORT, 0);
}
+static inline void input_mt_sync(struct input_dev *dev)
+{
+ input_event(dev, EV_SYN, SYN_MT_REPORT, 0);
+}
+
void input_set_capability(struct input_dev *dev, unsigned int type, unsigned int code);
static inline void input_set_abs_params(struct input_dev *dev, int axis, int min, int max, int fuzz, int flat)
--
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