[For Linux v1 2/4] xen/kbdif: add multi-touch support

From: Oleksandr Andrushchenko
Date: Mon Apr 10 2017 - 02:26:24 EST


From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

Multi-touch fields re-use the page that is used by the other features
which means that you can interleave multi-touch, motion, and key
events.

Acked-by: Juergen Gross <jgross@xxxxxxxx>
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
---
include/xen/interface/io/kbdif.h | 210 +++++++++++++++++++++++++++++++++++++++
1 file changed, 210 insertions(+)

diff --git a/include/xen/interface/io/kbdif.h b/include/xen/interface/io/kbdif.h
index 7adfb15fec9d..2a9510ade701 100644
--- a/include/xen/interface/io/kbdif.h
+++ b/include/xen/interface/io/kbdif.h
@@ -57,6 +57,12 @@
* Backends, which support reporting of absolute coordinates for pointer
* device should set this to 1.
*
+ * feature-multi-touch
+ * Values: <uint>
+ *
+ * Backends, which support reporting of multi-touch events
+ * should set this to 1.
+ *
*------------------------- Pointer Device Parameters ------------------------
*
* width
@@ -87,6 +93,11 @@
* Request backend to report absolute pointer coordinates
* (XENKBD_TYPE_POS) instead of relative ones (XENKBD_TYPE_MOTION).
*
+ * request-multi-touch
+ * Values: <uint>
+ *
+ * Request backend to report multi-touch events.
+ *
*----------------------- Request Transport Parameters -----------------------
*
* event-channel
@@ -106,6 +117,25 @@
*
* OBSOLETE, not recommended for use.
* PFN of the shared page.
+ *
+ *----------------------- Multi-touch Device Parameters -----------------------
+ *
+ * multi-touch-num-contacts
+ * Values: <uint>
+ *
+ * Number of simultaneous touches reported.
+ *
+ * multi-touch-width
+ * Values: <uint>
+ *
+ * Width of the touch area to be used by the frontend
+ * while reporting input events, pixels, [0; UINT32_MAX].
+ *
+ * multi-touch-height
+ * Values: <uint>
+ *
+ * Height of the touch area to be used by the frontend
+ * while reporting input events, pixels, [0; UINT32_MAX].
*/

/*
@@ -116,6 +146,16 @@
#define XENKBD_TYPE_RESERVED 2
#define XENKBD_TYPE_KEY 3
#define XENKBD_TYPE_POS 4
+#define XENKBD_TYPE_MTOUCH 5
+
+/* Multi-touch event sub-codes */
+
+#define XENKBD_MT_EV_DOWN 0
+#define XENKBD_MT_EV_UP 1
+#define XENKBD_MT_EV_MOTION 2
+#define XENKBD_MT_EV_SYN 3
+#define XENKBD_MT_EV_SHAPE 4
+#define XENKBD_MT_EV_ORIENT 5

/*
* CONSTANTS, XENSTORE FIELD AND PATH NAME STRINGS, HELPERS.
@@ -124,11 +164,16 @@
#define XENKBD_DRIVER_NAME "vkbd"

#define XENKBD_FIELD_FEAT_ABS_POINTER "feature-abs-pointer"
+#define XENKBD_FIELD_FEAT_MTOUCH "feature-multi-touch"
#define XENKBD_FIELD_REQ_ABS_POINTER "request-abs-pointer"
+#define XENKBD_FIELD_REQ_MTOUCH "request-multi-touch"
#define XENKBD_FIELD_RING_GREF "page-gref"
#define XENKBD_FIELD_EVT_CHANNEL "event-channel"
#define XENKBD_FIELD_WIDTH "width"
#define XENKBD_FIELD_HEIGHT "height"
+#define XENKBD_FIELD_MT_WIDTH "multi-touch-width"
+#define XENKBD_FIELD_MT_HEIGHT "multi-touch-height"
+#define XENKBD_FIELD_MT_NUM_CONTACTS "multi-touch-num-contacts"

/* OBSOLETE, not recommended for use */
#define XENKBD_FIELD_RING_REF "page-ref"
@@ -245,6 +290,170 @@ struct xenkbd_position {
int32_t rel_z;
};

+/*
+ * Multi-touch event and its sub-types
+ *
+ * All multi-touch event packets have common header:
+ *
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | _TYPE_MTOUCH | event_type | contact_id | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ *
+ * event_type - unt8_t, multi-touch event sub-type, XENKBD_MT_EV_???
+ * contact_id - unt8_t, ID of the contact
+ *
+ * Touch interactions can consist of one or more contacts.
+ * For each contact, a series of events is generated, starting
+ * with a down event, followed by zero or more motion events,
+ * and ending with an up event. Events relating to the same
+ * contact point can be identified by the ID of the sequence: contact ID.
+ * Contact ID may be reused after XENKBD_MT_EV_UP event and
+ * is in the [0; XENKBD_FIELD_NUM_CONTACTS - 1] range.
+ *
+ * For further information please refer to documentation on Wayland [1],
+ * Linux [2] and Windows [3] multi-touch support.
+ *
+ * [1] https://cgit.freedesktop.org/wayland/wayland/tree/protocol/wayland.xml
+ * [2] https://www.kernel.org/doc/Documentation/input/multi-touch-protocol.txt
+ * [3] https://msdn.microsoft.com/en-us/library/jj151564(v=vs.85).aspx
+ *
+ *
+ * Multi-touch down event - sent when a new touch is made: touch is assigned
+ * a unique contact ID, sent with this and consequent events related
+ * to this touch.
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | _TYPE_MTOUCH | _MT_EV_DOWN | contact_id | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | abs_x | 12
+ * +----------------+----------------+----------------+----------------+
+ * | abs_y | 16
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * abs_x - int32_t, absolute X position, in pixels
+ * abs_y - int32_t, absolute Y position, in pixels
+ *
+ * Multi-touch contact release event
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | _TYPE_MTOUCH | _MT_EV_UP | contact_id | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Multi-touch motion event
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | _TYPE_MTOUCH | _MT_EV_MOTION | contact_id | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | abs_x | 12
+ * +----------------+----------------+----------------+----------------+
+ * | abs_y | 16
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * abs_x - int32_t, absolute X position, in pixels,
+ * abs_y - int32_t, absolute Y position, in pixels,
+ *
+ * Multi-touch input synchronization event - shows end of a set of events
+ * which logically belong together.
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | _TYPE_MTOUCH | _MT_EV_SYN | contact_id | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * Multi-touch shape event - touch point's shape has changed its shape.
+ * Shape is approximated by an ellipse through the major and minor axis
+ * lengths: major is the longer diameter of the ellipse and minor is the
+ * shorter one. Center of the ellipse is reported via
+ * XENKBD_MT_EV_DOWN/XENKBD_MT_EV_MOTION events.
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | _TYPE_MTOUCH | _MT_EV_SHAPE | contact_id | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | major | 12
+ * +----------------+----------------+----------------+----------------+
+ * | minor | 16
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 20
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * major - unt32_t, length of the major axis, pixels
+ * minor - unt32_t, length of the minor axis, pixels
+ *
+ * Multi-touch orientation event - touch point's shape has changed
+ * its orientation: calculated as a clockwise angle between the major axis
+ * of the ellipse and positive Y axis in degrees, [-180; +180].
+ * 0 1 2 3 octet
+ * +----------------+----------------+----------------+----------------+
+ * | _TYPE_MTOUCH | _MT_EV_ORIENT | contact_id | reserved | 4
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 8
+ * +----------------+----------------+----------------+----------------+
+ * | orientation | reserved | 12
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 16
+ * +----------------+----------------+----------------+----------------+
+ * |/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/|
+ * +----------------+----------------+----------------+----------------+
+ * | reserved | 40
+ * +----------------+----------------+----------------+----------------+
+ *
+ * orientation - int16_t, clockwise angle of the major axis
+ */
+
+struct xenkbd_mtouch {
+ uint8_t type; /* XENKBD_TYPE_MTOUCH */
+ uint8_t event_type; /* XENKBD_MT_EV_??? */
+ uint8_t contact_id;
+ uint8_t reserved[5]; /* reserved for the future use */
+ union {
+ struct {
+ int32_t abs_x; /* absolute X position, pixels */
+ int32_t abs_y; /* absolute Y position, pixels */
+ } pos;
+ struct {
+ uint32_t major; /* length of the major axis, pixels */
+ uint32_t minor; /* length of the minor axis, pixels */
+ } shape;
+ int16_t orientation; /* clockwise angle of the major axis */
+ } u;
+};
+
#define XENKBD_IN_EVENT_SIZE 40

union xenkbd_in_event {
@@ -252,6 +461,7 @@ union xenkbd_in_event {
struct xenkbd_motion motion;
struct xenkbd_key key;
struct xenkbd_position pos;
+ struct xenkbd_mtouch mtouch;
char pad[XENKBD_IN_EVENT_SIZE];
};

--
2.7.4