[PATCH 2/3] Input: synaptics - add multitouch multifinger support

[Chase Douglas <chase.douglas@canonical.com>]

Newer multitouch Synaptics trackpads do not advertise multifinger
support. Now that we have multitouch support, we can use the number of
touches to report multifinger functionality.

In conjunction with the X synaptics input module, this enables
functionality such as two finger scrolling.

Signed-off-by: Chase Douglas <chase.douglas@canonical.com>
---
 drivers/input/mouse/synaptics.c |   24 +++++++++++++-----------
 drivers/input/mouse/synaptics.h |    1 +
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c
index 990598f..7289d88 100644
--- a/drivers/input/mouse/synaptics.c
+++ b/drivers/input/mouse/synaptics.c
@@ -471,7 +471,6 @@ static void synaptics_process_packet(struct psmouse *psmouse)
 	struct input_dev *dev = psmouse->dev;
 	struct synaptics_data *priv = psmouse->private;
 	struct synaptics_hw_state hw;
-	int num_fingers;
 	int finger_width;
 	int i;
 
@@ -483,6 +482,7 @@ static void synaptics_process_packet(struct psmouse *psmouse)
 			input_report_abs(dev, ABS_MT_POSITION_Y,
 					 YMAX_NOMINAL + YMIN_NOMINAL - hw.y);
 			input_report_abs(dev, ABS_MT_PRESSURE, hw.z);
+			priv->num_fingers++;
 		}
 
 		input_mt_sync(dev);
@@ -510,13 +510,13 @@ static void synaptics_process_packet(struct psmouse *psmouse)
 	}
 
 	if (hw.z > 0) {
-		num_fingers = 1;
+		priv->num_fingers++;
 		finger_width = 5;
 		if (SYN_CAP_EXTENDED(priv->capabilities)) {
 			switch (hw.w) {
 			case 0 ... 1:
 				if (SYN_CAP_MULTIFINGER(priv->capabilities))
-					num_fingers = hw.w + 2;
+					priv->num_fingers = hw.w + 2;
 				break;
 			case 2:
 				if (SYN_MODEL_PEN(priv->model_id))
@@ -528,10 +528,8 @@ static void synaptics_process_packet(struct psmouse *psmouse)
 				break;
 			}
 		}
-	} else {
-		num_fingers = 0;
+	} else
 		finger_width = 0;
-	}
 
 	/* Post events
 	 * BTN_TOUCH has to be first as mousedev relies on it when doing
@@ -555,15 +553,19 @@ static void synaptics_process_packet(struct psmouse *psmouse)
 	if (SYN_CAP_PALMDETECT(priv->capabilities))
 		input_report_abs(dev, ABS_TOOL_WIDTH, finger_width);
 
-	input_report_key(dev, BTN_TOOL_FINGER, num_fingers == 1);
+	input_report_key(dev, BTN_TOOL_FINGER, priv->num_fingers == 1);
 	input_report_key(dev, BTN_LEFT, hw.left);
 	input_report_key(dev, BTN_RIGHT, hw.right);
 
-	if (SYN_CAP_MULTIFINGER(priv->capabilities)) {
-		input_report_key(dev, BTN_TOOL_DOUBLETAP, num_fingers == 2);
-		input_report_key(dev, BTN_TOOL_TRIPLETAP, num_fingers == 3);
+	if (SYN_CAP_MULTIFINGER(priv->capabilities) || priv->multitouch) {
+		input_report_key(dev, BTN_TOOL_DOUBLETAP,
+				 priv->num_fingers == 2);
+		input_report_key(dev, BTN_TOOL_TRIPLETAP,
+				 priv->num_fingers == 3);
 	}
 
+	priv->num_fingers = 0;
+
 	if (SYN_CAP_MIDDLE_BUTTON(priv->capabilities))
 		input_report_key(dev, BTN_MIDDLE, hw.middle);
 
@@ -674,7 +676,7 @@ static void set_input_params(struct input_dev *dev, struct synaptics_data *priv)
 	__set_bit(BTN_LEFT, dev->keybit);
 	__set_bit(BTN_RIGHT, dev->keybit);
 
-	if (SYN_CAP_MULTIFINGER(priv->capabilities)) {
+	if (SYN_CAP_MULTIFINGER(priv->capabilities) || priv->multitouch) {
 		__set_bit(BTN_TOOL_DOUBLETAP, dev->keybit);
 		__set_bit(BTN_TOOL_TRIPLETAP, dev->keybit);
 	}
diff --git a/drivers/input/mouse/synaptics.h b/drivers/input/mouse/synaptics.h
index 5126c9c..0989b8d 100644
--- a/drivers/input/mouse/synaptics.h
+++ b/drivers/input/mouse/synaptics.h
@@ -113,6 +113,7 @@ struct synaptics_data {
 	unsigned char mode;			/* current mode byte */
 	int scroll;
 	int multitouch;				/* Whether device provides MT */
+	unsigned int num_fingers;		/* Number of fingers touching */
 };
 
 void synaptics_module_init(void);
-- 
1.7.1