1 files changed, 44 insertions, 1 deletions

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index aec9cf7124f..30c85a5b718 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -762,6 +762,10 @@ static void synaptics_image_sensor_1f(struct synaptics_data *priv,
                 synaptics_mt_state_set(mt_state, 1, -1, -1);
                 priv->mt_state_lost = true;
                 break;
+        case 4:
+        case 5:
+                /* mt_state was updated by AGM-CONTACT packet */
+                break;
         }
 }
 
@@ -816,6 +820,10 @@ static void synaptics_image_sensor_2f(struct synaptics_data *priv,
                 synaptics_mt_state_set(mt_state, 2, -1, -1);
                 priv->mt_state_lost = true;
                 break;
+        case 4:
+        case 5:
+                /* mt_state was updated by AGM-CONTACT packet */
+                break;
         }
 }
 
@@ -844,6 +852,22 @@ static void synaptics_image_sensor_3f(struct synaptics_data *priv,
                 break;
         case 2:
                 /*
+                 * If the AGM previously contained slot 3 or higher, then the
+                 * newly touching finger is in the lowest available slot.
+                 *
+                 * If SGM was previously 1 or higher, then the new SGM is
+                 * now slot 0 (with a new finger), otherwise, the new finger
+                 * is now in a hidden slot between 0 and AGM's slot.
+                 *
+                 * In all such cases, the SGM now contains slot 0, and the AGM
+                 * continues to contain the same slot as before.
+                 */
+                if (old->agm >= 3) {
+                        synaptics_mt_state_set(mt_state, 3, 0, old->agm);
+                        break;
+                }
+
+                /*
                  * After some 3->1 and all 3->2 transitions, we lose track
                  * of which slot is reported by SGM and AGM.
                  *
@@ -883,9 +907,22 @@ static void synaptics_image_sensor_3f(struct synaptics_data *priv,
                  * received AGM-CONTACT packet.
                  */
                 break;
+
+        case 4:
+        case 5:
+                /* mt_state was updated by AGM-CONTACT packet */
+                break;
         }
 }
 
+/* Handle case where mt_state->count = 4, or = 5 */
+static void synaptics_image_sensor_45f(struct synaptics_data *priv,
+                                       struct synaptics_mt_state *mt_state)
+{
+        /* mt_state was updated correctly by AGM-CONTACT packet */
+        priv->mt_state_lost = false;
+}
+
 static void synaptics_image_sensor_process(struct psmouse *psmouse,
                                            struct synaptics_hw_state *sgm)
 {
@@ -905,8 +942,10 @@ static void synaptics_image_sensor_process(struct psmouse *psmouse,
                 synaptics_image_sensor_1f(priv, &mt_state);
         else if (sgm->w == 0)
                 synaptics_image_sensor_2f(priv, &mt_state);
-        else if (sgm->w == 1)
+        else if (sgm->w == 1 && mt_state.count <= 3)
                 synaptics_image_sensor_3f(priv, &mt_state);
+        else
+                synaptics_image_sensor_45f(priv, &mt_state);
 
         /* Send resulting input events to user space */
         synaptics_report_mt_data(psmouse, &mt_state, sgm);
@@ -1110,6 +1149,10 @@ static void set_input_params(struct input_dev *dev, struct synaptics_data *priv)
                                         ABS_MT_POSITION_Y);
                 /* Image sensors can report per-contact pressure */
                 input_set_abs_params(dev, ABS_MT_PRESSURE, 0, 255, 0, 0);
+
+                /* Image sensors can signal 4 and 5 finger clicks */
+                __set_bit(BTN_TOOL_QUADTAP, dev->keybit);
+                __set_bit(BTN_TOOL_QUINTTAP, dev->keybit);
         } else if (SYN_CAP_ADV_GESTURE(priv->ext_cap_0c)) {
                 /* Non-image sensors with AGM use semi-mt */
                 __set_bit(INPUT_PROP_SEMI_MT, dev->propbit);