1 files changed, 110 insertions, 5 deletions

diff --git a/drivers/input/input-mt.c b/drivers/input/input-mt.c
index f400e47092c4..c48c81f0308d 100644
--- a/drivers/input/input-mt.c
+++ b/drivers/input/input-mt.c
@@ -11,17 +11,18 @@
 #include <linux/input/mt.h>
 #include <linux/slab.h>
 
+#define TRKID_SGN       ((TRKID_MAX + 1) >> 1)
+
 /**
  * input_mt_init_slots() - initialize MT input slots
  * @dev: input device supporting MT events and finger tracking
  * @num_slots: number of slots used by the device
  *
  * This function allocates all necessary memory for MT slot handling
- * in the input device, adds ABS_MT_SLOT to the device capabilities
- * and sets up appropriate event buffers. All slots are initially
- * marked as unused by setting ABS_MT_TRACKING_ID to -1. May be called
- * repeatedly. Returns -EINVAL if attempting to reinitialize with a
- * different number of slots.
+ * in the input device, prepares the ABS_MT_SLOT and
+ * ABS_MT_TRACKING_ID events for use and sets up appropriate buffers.
+ * May be called repeatedly. Returns -EINVAL if attempting to
+ * reinitialize with a different number of slots.
  */
 int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
 {
@@ -38,6 +39,7 @@ int input_mt_init_slots(struct input_dev *dev, unsigned int num_slots)
 
         dev->mtsize = num_slots;
         input_set_abs_params(dev, ABS_MT_SLOT, 0, num_slots - 1, 0, 0);
+        input_set_abs_params(dev, ABS_MT_TRACKING_ID, 0, TRKID_MAX, 0, 0);
         input_set_events_per_packet(dev, 6 * num_slots);
 
         /* Mark slots as 'unused' */
@@ -61,5 +63,108 @@ void input_mt_destroy_slots(struct input_dev *dev)
         dev->mt = NULL;
         dev->mtsize = 0;
         dev->slot = 0;
+        dev->trkid = 0;
 }
 EXPORT_SYMBOL(input_mt_destroy_slots);
+
+/**
+ * input_mt_report_slot_state() - report contact state
+ * @dev: input device with allocated MT slots
+ * @tool_type: the tool type to use in this slot
+ * @active: true if contact is active, false otherwise
+ *
+ * Reports a contact via ABS_MT_TRACKING_ID, and optionally
+ * ABS_MT_TOOL_TYPE. If active is true and the slot is currently
+ * inactive, or if the tool type is changed, a new tracking id is
+ * assigned to the slot. The tool type is only reported if the
+ * corresponding absbit field is set.
+ */
+void input_mt_report_slot_state(struct input_dev *dev,
+                                unsigned int tool_type, bool active)
+{
+        struct input_mt_slot *mt;
+        int id;
+
+        if (!dev->mt || !active) {
+                input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, -1);
+                return;
+        }
+
+        mt = &dev->mt[dev->slot];
+        id = input_mt_get_value(mt, ABS_MT_TRACKING_ID);
+        if (id < 0 || input_mt_get_value(mt, ABS_MT_TOOL_TYPE) != tool_type)
+                id = input_mt_new_trkid(dev);
+
+        input_event(dev, EV_ABS, ABS_MT_TRACKING_ID, id);
+        input_event(dev, EV_ABS, ABS_MT_TOOL_TYPE, tool_type);
+}
+EXPORT_SYMBOL(input_mt_report_slot_state);
+
+/**
+ * input_mt_report_finger_count() - report contact count
+ * @dev: input device with allocated MT slots
+ * @count: the number of contacts
+ *
+ * Reports the contact count via BTN_TOOL_FINGER, BTN_TOOL_DOUBLETAP,
+ * BTN_TOOL_TRIPLETAP and BTN_TOOL_QUADTAP.
+ *
+ * The input core ensures only the KEY events already setup for
+ * this device will produce output.
+ */
+void input_mt_report_finger_count(struct input_dev *dev, int count)
+{
+        input_event(dev, EV_KEY, BTN_TOOL_FINGER, count == 1);
+        input_event(dev, EV_KEY, BTN_TOOL_DOUBLETAP, count == 2);
+        input_event(dev, EV_KEY, BTN_TOOL_TRIPLETAP, count == 3);
+        input_event(dev, EV_KEY, BTN_TOOL_QUADTAP, count == 4);
+}
+EXPORT_SYMBOL(input_mt_report_finger_count);
+
+/**
+ * input_mt_report_pointer_emulation() - common pointer emulation
+ * @dev: input device with allocated MT slots
+ * @use_count: report number of active contacts as finger count
+ *
+ * Performs legacy pointer emulation via BTN_TOUCH, ABS_X, ABS_Y and
+ * ABS_PRESSURE. Touchpad finger count is emulated if use_count is true.
+ *
+ * The input core ensures only the KEY and ABS axes already setup for
+ * this device will produce output.
+ */
+void input_mt_report_pointer_emulation(struct input_dev *dev, bool use_count)
+{
+        struct input_mt_slot *oldest = 0;
+        int oldid = dev->trkid;
+        int count = 0;
+        int i;
+
+        for (i = 0; i < dev->mtsize; ++i) {
+                struct input_mt_slot *ps = &dev->mt[i];
+                int id = input_mt_get_value(ps, ABS_MT_TRACKING_ID);
+
+                if (id < 0)
+                        continue;
+                if ((id - oldid) & TRKID_SGN) {
+                        oldest = ps;
+                        oldid = id;
+                }
+                count++;
+        }
+
+        input_event(dev, EV_KEY, BTN_TOUCH, count > 0);
+        if (use_count)
+                input_mt_report_finger_count(dev, count);
+
+        if (oldest) {
+                int x = input_mt_get_value(oldest, ABS_MT_POSITION_X);
+                int y = input_mt_get_value(oldest, ABS_MT_POSITION_Y);
+                int p = input_mt_get_value(oldest, ABS_MT_PRESSURE);
+
+                input_event(dev, EV_ABS, ABS_X, x);
+                input_event(dev, EV_ABS, ABS_Y, y);
+                input_event(dev, EV_ABS, ABS_PRESSURE, p);
+        } else {
+                input_event(dev, EV_ABS, ABS_PRESSURE, 0);
+        }
+}
+EXPORT_SYMBOL(input_mt_report_pointer_emulation);