Input: xen-kbdfront - add multi-touch support

Extend xen_kbdfront to provide multi-touch support to unprivileged domains.
Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com>
[dtor: factor out various sub-protocols - multitouch, single touch, keys]
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/misc/xen-kbdfront.c

@@ -17,6 +17,7 @@
 #include <linux/errno.h>
 #include <linux/module.h>
 #include <linux/input.h>
+#include <linux/input/mt.h>
 #include <linux/slab.h>
 
 #include <asm/xen/hypervisor.h>
@@ -34,11 +35,14 @@
 struct xenkbd_info {
 	struct input_dev *kbd;
 	struct input_dev *ptr;
+	struct input_dev *mtouch;
 	struct xenkbd_page *page;
 	int gref;
 	int irq;
 	struct xenbus_device *xbdev;
 	char phys[32];
+	/* current MT slot/contact ID we are injecting events in */
+	int mtouch_cur_contact_id;
 };
 
 enum { KPARAM_X, KPARAM_Y, KPARAM_CNT };
@@ -56,6 +60,112 @@ static void xenkbd_disconnect_backend(struct xenkbd_info *);
  * to do that.
  */
 
+static void xenkbd_handle_motion_event(struct xenkbd_info *info,
+				       struct xenkbd_motion *motion)
+{
+	input_report_rel(info->ptr, REL_X, motion->rel_x);
+	input_report_rel(info->ptr, REL_Y, motion->rel_y);
+	if (motion->rel_z)
+		input_report_rel(info->ptr, REL_WHEEL, -motion->rel_z);
+	input_sync(info->ptr);
+}
+
+static void xenkbd_handle_position_event(struct xenkbd_info *info,
+					 struct xenkbd_position *pos)
+{
+	input_report_abs(info->ptr, ABS_X, pos->abs_x);
+	input_report_abs(info->ptr, ABS_Y, pos->abs_y);
+	if (pos->rel_z)
+		input_report_rel(info->ptr, REL_WHEEL, -pos->rel_z);
+	input_sync(info->ptr);
+}
+
+static void xenkbd_handle_key_event(struct xenkbd_info *info,
+				    struct xenkbd_key *key)
+{
+	struct input_dev *dev;
+
+	if (test_bit(key->keycode, info->ptr->keybit)) {
+		dev = info->ptr;
+	} else if (test_bit(key->keycode, info->kbd->keybit)) {
+		dev = info->kbd;
+	} else {
+		pr_warn("unhandled keycode 0x%x\n", key->keycode);
+		return;
+	}
+
+	input_report_key(dev, key->keycode, key->pressed);
+	input_sync(dev);
+}
+
+static void xenkbd_handle_mt_event(struct xenkbd_info *info,
+				   struct xenkbd_mtouch *mtouch)
+{
+	if (unlikely(!info->mtouch))
+		return;
+
+	if (mtouch->contact_id != info->mtouch_cur_contact_id) {
+		info->mtouch_cur_contact_id = mtouch->contact_id;
+		input_mt_slot(info->mtouch, mtouch->contact_id);
+	}
+
+	switch (mtouch->event_type) {
+	case XENKBD_MT_EV_DOWN:
+		input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, true);
+		/* fall through */
+
+	case XENKBD_MT_EV_MOTION:
+		input_report_abs(info->mtouch, ABS_MT_POSITION_X,
+				 mtouch->u.pos.abs_x);
+		input_report_abs(info->mtouch, ABS_MT_POSITION_Y,
+				 mtouch->u.pos.abs_y);
+		break;
+
+	case XENKBD_MT_EV_SHAPE:
+		input_report_abs(info->mtouch, ABS_MT_TOUCH_MAJOR,
+				 mtouch->u.shape.major);
+		input_report_abs(info->mtouch, ABS_MT_TOUCH_MINOR,
+				 mtouch->u.shape.minor);
+		break;
+
+	case XENKBD_MT_EV_ORIENT:
+		input_report_abs(info->mtouch, ABS_MT_ORIENTATION,
+				 mtouch->u.orientation);
+		break;
+
+	case XENKBD_MT_EV_UP:
+		input_mt_report_slot_state(info->mtouch, MT_TOOL_FINGER, false);
+		break;
+
+	case XENKBD_MT_EV_SYN:
+		input_mt_sync_frame(info->mtouch);
+		input_sync(info->mtouch);
+		break;
+	}
+}
+
+static void xenkbd_handle_event(struct xenkbd_info *info,
+				union xenkbd_in_event *event)
+{
+	switch (event->type) {
+	case XENKBD_TYPE_MOTION:
+		xenkbd_handle_motion_event(info, &event->motion);
+		break;
+
+	case XENKBD_TYPE_KEY:
+		xenkbd_handle_key_event(info, &event->key);
+		break;
+
+	case XENKBD_TYPE_POS:
+		xenkbd_handle_position_event(info, &event->pos);
+		break;
+
+	case XENKBD_TYPE_MTOUCH:
+		xenkbd_handle_mt_event(info, &event->mtouch);
+		break;
+	}
+}
+
 static irqreturn_t input_handler(int rq, void *dev_id)
 {
 	struct xenkbd_info *info = dev_id;
@@ -66,44 +176,8 @@ static irqreturn_t input_handler(int rq, void *dev_id)
 	if (prod == page->in_cons)
 		return IRQ_HANDLED;
 	rmb();			/* ensure we see ring contents up to prod */
-	for (cons = page->in_cons; cons != prod; cons++) {
-		union xenkbd_in_event *event;
-		struct input_dev *dev;
-		event = &XENKBD_IN_RING_REF(page, cons);
-
-		dev = info->ptr;
-		switch (event->type) {
-		case XENKBD_TYPE_MOTION:
-			input_report_rel(dev, REL_X, event->motion.rel_x);
-			input_report_rel(dev, REL_Y, event->motion.rel_y);
-			if (event->motion.rel_z)
-				input_report_rel(dev, REL_WHEEL,
-						 -event->motion.rel_z);
-			break;
-		case XENKBD_TYPE_KEY:
-			dev = NULL;
-			if (test_bit(event->key.keycode, info->kbd->keybit))
-				dev = info->kbd;
-			if (test_bit(event->key.keycode, info->ptr->keybit))
-				dev = info->ptr;
-			if (dev)
-				input_report_key(dev, event->key.keycode,
-						 event->key.pressed);
-			else
-				pr_warn("unhandled keycode 0x%x\n",
-					event->key.keycode);
-			break;
-		case XENKBD_TYPE_POS:
-			input_report_abs(dev, ABS_X, event->pos.abs_x);
-			input_report_abs(dev, ABS_Y, event->pos.abs_y);
-			if (event->pos.rel_z)
-				input_report_rel(dev, REL_WHEEL,
-						 -event->pos.rel_z);
-			break;
-		}
-		if (dev)
-			input_sync(dev);
-	}
+	for (cons = page->in_cons; cons != prod; cons++)
+		xenkbd_handle_event(info, &XENKBD_IN_RING_REF(page, cons));
 	mb();			/* ensure we got ring contents */
 	page->in_cons = cons;
 	notify_remote_via_irq(info->irq);
@@ -115,9 +189,9 @@ static int xenkbd_probe(struct xenbus_device *dev,
 				  const struct xenbus_device_id *id)
 {
 	int ret, i;
-	unsigned int abs;
+	unsigned int abs, touch;
 	struct xenkbd_info *info;
-	struct input_dev *kbd, *ptr;
+	struct input_dev *kbd, *ptr, *mtouch;
 
 	info = kzalloc(sizeof(*info), GFP_KERNEL);
 	if (!info) {
@@ -152,6 +226,17 @@ static int xenkbd_probe(struct xenbus_device *dev,
 		}
 	}
 
+	touch = xenbus_read_unsigned(dev->nodename,
+				     XENKBD_FIELD_FEAT_MTOUCH, 0);
+	if (touch) {
+		ret = xenbus_write(XBT_NIL, dev->nodename,
+				   XENKBD_FIELD_REQ_MTOUCH, "1");
+		if (ret) {
+			pr_warn("xenkbd: can't request multi-touch");
+			touch = 0;
+		}
+	}
+
 	/* keyboard */
 	kbd = input_allocate_device();
 	if (!kbd)
@@ -208,6 +293,58 @@ static int xenkbd_probe(struct xenbus_device *dev,
 	}
 	info->ptr = ptr;
 
+	/* multi-touch device */
+	if (touch) {
+		int num_cont, width, height;
+
+		mtouch = input_allocate_device();
+		if (!mtouch)
+			goto error_nomem;
+
+		num_cont = xenbus_read_unsigned(info->xbdev->nodename,
+						XENKBD_FIELD_MT_NUM_CONTACTS,
+						1);
+		width = xenbus_read_unsigned(info->xbdev->nodename,
+					     XENKBD_FIELD_MT_WIDTH,
+					     XENFB_WIDTH);
+		height = xenbus_read_unsigned(info->xbdev->nodename,
+					      XENKBD_FIELD_MT_HEIGHT,
+					      XENFB_HEIGHT);
+
+		mtouch->name = "Xen Virtual Multi-touch";
+		mtouch->phys = info->phys;
+		mtouch->id.bustype = BUS_PCI;
+		mtouch->id.vendor = 0x5853;
+		mtouch->id.product = 0xfffd;
+
+		input_set_abs_params(mtouch, ABS_MT_TOUCH_MAJOR,
+				     0, 255, 0, 0);
+		input_set_abs_params(mtouch, ABS_MT_POSITION_X,
+				     0, width, 0, 0);
+		input_set_abs_params(mtouch, ABS_MT_POSITION_Y,
+				     0, height, 0, 0);
+		input_set_abs_params(mtouch, ABS_MT_PRESSURE,
+				     0, 255, 0, 0);
+
+		ret = input_mt_init_slots(mtouch, num_cont, INPUT_MT_DIRECT);
+		if (ret) {
+			input_free_device(mtouch);
+			xenbus_dev_fatal(info->xbdev, ret,
+					 "input_mt_init_slots");
+			goto error;
+		}
+
+		ret = input_register_device(mtouch);
+		if (ret) {
+			input_free_device(mtouch);
+			xenbus_dev_fatal(info->xbdev, ret,
+					 "input_register_device(mtouch)");
+			goto error;
+		}
+		info->mtouch_cur_contact_id = -1;
+		info->mtouch = mtouch;
+	}
+
 	ret = xenkbd_connect_backend(dev, info);
 	if (ret < 0)
 		goto error;
@@ -240,6 +377,8 @@ static int xenkbd_remove(struct xenbus_device *dev)
 		input_unregister_device(info->kbd);
 	if (info->ptr)
 		input_unregister_device(info->ptr);
+	if (info->mtouch)
+		input_unregister_device(info->mtouch);
 	free_page((unsigned long)info->page);
 	kfree(info);
 	return 0;