2 files changed, 133 insertions, 48 deletions

diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index 0d3219f2974..9edf9806cff 100644
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -172,6 +172,76 @@ static void wacom_close(struct input_dev *dev)
 }
 
 /*
+ * Calculate the resolution of the X or Y axis, given appropriate HID data.
+ * This function is little more than hidinput_calc_abs_res stripped down.
+ */
+static int wacom_calc_hid_res(int logical_extents, int physical_extents,
+                              unsigned char unit, unsigned char exponent)
+{
+	int prev, unit_exponent;
+
+	/* Check if the extents are sane */
+	if (logical_extents <= 0 || physical_extents <= 0)
+		return 0;
+
+	/* Get signed value of nybble-sized twos-compliment exponent */
+	unit_exponent = exponent;
+	if (unit_exponent > 7)
+		unit_exponent -= 16;
+
+	/* Convert physical_extents to millimeters */
+	if (unit == 0x11) {		/* If centimeters */
+		unit_exponent += 1;
+	} else if (unit == 0x13) {	/* If inches */
+		prev = physical_extents;
+		physical_extents *= 254;
+		if (physical_extents < prev)
+			return 0;
+		unit_exponent -= 1;
+	} else {
+		return 0;
+	}
+
+	/* Apply negative unit exponent */
+	for (; unit_exponent < 0; unit_exponent++) {
+		prev = logical_extents;
+		logical_extents *= 10;
+		if (logical_extents < prev)
+			return 0;
+	}
+	/* Apply positive unit exponent */
+	for (; unit_exponent > 0; unit_exponent--) {
+		prev = physical_extents;
+		physical_extents *= 10;
+		if (physical_extents < prev)
+			return 0;
+	}
+
+	/* Calculate resolution */
+	return logical_extents / physical_extents;
+}
+
+/*
+ * The physical dimension specified by the HID descriptor is likely not in
+ * the "100th of a mm" units expected by wacom_calculate_touch_res. This
+ * function adjusts the value of [xy]_phy based on the unit and exponent
+ * provided by the HID descriptor. If an error occurs durring conversion
+ * (e.g. from the unit being left unspecified) [xy]_phy is not modified.
+ */
+static void wacom_fix_phy_from_hid(struct wacom_features *features)
+{
+	int xres = wacom_calc_hid_res(features->x_max, features->x_phy,
+					features->unit, features->unitExpo);
+	int yres = wacom_calc_hid_res(features->y_max, features->y_phy,
+					features->unit, features->unitExpo);
+
+	if (xres > 0 && yres > 0) {
+		features->x_phy = (100 * features->x_max) / xres;
+		features->y_phy = (100 * features->y_max) / yres;
+	}
+}
+
+/*
  * Static values for max X/Y and resolution of Pen interface is stored in
  * features. This mean physical size of active area can be computed.
  * This is useful to do when Pen and Touch have same active area of tablet.
@@ -432,56 +502,52 @@ static int wacom_parse_hid(struct usb_interface *intf,
 	return result;
 }
 
-static int wacom_query_tablet_data(struct usb_interface *intf, struct wacom_features *features)
+static int wacom_set_device_mode(struct usb_interface *intf, int report_id, int length, int mode)
 {
 	unsigned char *rep_data;
-	int limit = 0, report_id = 2;
-	int error = -ENOMEM;
+	int error = -ENOMEM, limit = 0;
 
-	rep_data = kmalloc(4, GFP_KERNEL);
+	rep_data = kzalloc(length, GFP_KERNEL);
 	if (!rep_data)
 		return error;
 
-	/* ask to report Wacom data */
+	rep_data[0] = report_id;
+	rep_data[1] = mode;
+
+	do {
+		error = wacom_set_report(intf, WAC_HID_FEATURE_REPORT,
+		                         report_id, rep_data, length, 1);
+		if (error >= 0)
+			error = wacom_get_report(intf, WAC_HID_FEATURE_REPORT,
+			                         report_id, rep_data, length, 1);
+	} while ((error < 0 || rep_data[1] != mode) && limit++ < WAC_MSG_RETRIES);
+
+	kfree(rep_data);
+
+	return error < 0 ? error : 0;
+}
+
+/*
+ * Switch the tablet into its most-capable mode. Wacom tablets are
+ * typically configured to power-up in a mode which sends mouse-like
+ * reports to the OS. To get absolute position, pressure data, etc.
+ * from the tablet, it is necessary to switch the tablet out of this
+ * mode and into one which sends the full range of tablet data.
+ */
+static int wacom_query_tablet_data(struct usb_interface *intf, struct wacom_features *features)
+{
 	if (features->device_type == BTN_TOOL_FINGER) {
-		/* if it is an MT Tablet PC touch */
 		if (features->type > TABLETPC) {
-			do {
-				rep_data[0] = 3;
-				rep_data[1] = 4;
-				rep_data[2] = 0;
-				rep_data[3] = 0;
-				report_id = 3;
-				error = wacom_set_report(intf,
-							 WAC_HID_FEATURE_REPORT,
-							 report_id,
-							 rep_data, 4, 1);
-				if (error >= 0)
-					error = wacom_get_report(intf,
-							WAC_HID_FEATURE_REPORT,
-							report_id,
-							rep_data, 4, 1);
-			} while ((error < 0 || rep_data[1] != 4) &&
-				 limit++ < WAC_MSG_RETRIES);
+			/* MT Tablet PC touch */
+			return wacom_set_device_mode(intf, 3, 4, 4);
+		}
+	} else if (features->device_type == BTN_TOOL_PEN) {
+		if (features->type <= BAMBOO_PT && features->type != WIRELESS) {
+			return wacom_set_device_mode(intf, 2, 2, 2);
 		}
-	} else if (features->type <= BAMBOO_PT &&
-		   features->type != WIRELESS &&
-		   features->device_type == BTN_TOOL_PEN) {
-		do {
-			rep_data[0] = 2;
-			rep_data[1] = 2;
-			error = wacom_set_report(intf, WAC_HID_FEATURE_REPORT,
-						 report_id, rep_data, 2, 1);
-			if (error >= 0)
-				error = wacom_get_report(intf,
-						WAC_HID_FEATURE_REPORT,
-						report_id, rep_data, 2, 1);
-		} while ((error < 0 || rep_data[1] != 2) && limit++ < WAC_MSG_RETRIES);
 	}
 
-	kfree(rep_data);
-
-	return error < 0 ? error : 0;
+	return 0;
 }
 
 static int wacom_retrieve_hid_descriptor(struct usb_interface *intf,
@@ -531,6 +597,7 @@ static int wacom_retrieve_hid_descriptor(struct usb_interface *intf,
 	error = wacom_parse_hid(intf, hid_desc, features);
 	if (error)
 		goto out;
+	wacom_fix_phy_from_hid(features);
 
  out:
 	return error;
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index 93171098abb..c3468c8dbd8 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -25,6 +25,11 @@
 #define WACOM_INTUOS_RES	100
 #define WACOM_INTUOS3_RES	200
 
+/* Scale factor relating reported contact size to logical contact area.
+ * 2^14/pi is a good approximation on Intuos5 and 3rd-gen Bamboo
+ */
+#define WACOM_CONTACT_AREA_SCALE 2607
+
 static int wacom_penpartner_irq(struct wacom_wac *wacom)
 {
 	unsigned char *data = wacom->data;
@@ -326,7 +331,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 
 	/* Enter report */
 	if ((data[1] & 0xfc) == 0xc0) {
-		if (features->type >= INTUOS5S && features->type <= INTUOS5L)
+		if (features->quirks == WACOM_QUIRK_MULTI_INPUT)
 			wacom->shared->stylus_in_proximity = true;
 
 		/* serial number of the tool */
@@ -414,7 +419,7 @@ static int wacom_intuos_inout(struct wacom_wac *wacom)
 
 	/* Exit report */
 	if ((data[1] & 0xfe) == 0x80) {
-		if (features->type >= INTUOS5S && features->type <= INTUOS5L)
+		if (features->quirks == WACOM_QUIRK_MULTI_INPUT)
 			wacom->shared->stylus_in_proximity = false;
 
 		/*
@@ -1043,11 +1048,19 @@ static void wacom_bpt3_touch_msg(struct wacom_wac *wacom, unsigned char *data)
 	if (touch) {
 		int x = (data[2] << 4) | (data[4] >> 4);
 		int y = (data[3] << 4) | (data[4] & 0x0f);
-		int w = data[6];
+		int a = data[5];
+
+		// "a" is a scaled-down area which we assume is roughly
+		// circular and which can be described as: a=(pi*r^2)/C.
+		int x_res  = input_abs_get_res(input, ABS_X);
+		int y_res  = input_abs_get_res(input, ABS_Y);
+		int width  = 2 * int_sqrt(a * WACOM_CONTACT_AREA_SCALE);
+		int height = width * y_res / x_res;
 
 		input_report_abs(input, ABS_MT_POSITION_X, x);
 		input_report_abs(input, ABS_MT_POSITION_Y, y);
-		input_report_abs(input, ABS_MT_TOUCH_MAJOR, w);
+		input_report_abs(input, ABS_MT_TOUCH_MAJOR, width);
+		input_report_abs(input, ABS_MT_TOUCH_MINOR, height);
 	}
 }
 
@@ -1530,10 +1543,12 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
 			__set_bit(BTN_TOOL_TRIPLETAP, input_dev->keybit);
 			__set_bit(BTN_TOOL_QUADTAP, input_dev->keybit);
 
-			input_mt_init_slots(input_dev, features->touch_max);
+			input_mt_init_slots(input_dev, features->touch_max, 0);
 
 			input_set_abs_params(input_dev, ABS_MT_TOUCH_MAJOR,
-			                     0, 255, 0, 0);
+			                     0, features->x_max, 0, 0);
+			input_set_abs_params(input_dev, ABS_MT_TOUCH_MINOR,
+			                     0, features->y_max, 0, 0);
 
 			input_set_abs_params(input_dev, ABS_MT_POSITION_X,
 					     0, features->x_max,
@@ -1575,7 +1590,7 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
 
 	case TABLETPC2FG:
 		if (features->device_type == BTN_TOOL_FINGER) {
-			input_mt_init_slots(input_dev, features->touch_max);
+			input_mt_init_slots(input_dev, features->touch_max, 0);
 			input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE,
 					0, MT_TOOL_MAX, 0, 0);
 			input_set_abs_params(input_dev, ABS_MT_POSITION_X,
@@ -1631,7 +1646,7 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
 
 			__set_bit(BTN_TOOL_FINGER, input_dev->keybit);
 			__set_bit(BTN_TOOL_DOUBLETAP, input_dev->keybit);
-			input_mt_init_slots(input_dev, features->touch_max);
+			input_mt_init_slots(input_dev, features->touch_max, 0);
 
 			if (features->pktlen == WACOM_PKGLEN_BBTOUCH3) {
 				__set_bit(BTN_TOOL_TRIPLETAP,
@@ -1641,7 +1656,10 @@ int wacom_setup_input_capabilities(struct input_dev *input_dev,
 
 				input_set_abs_params(input_dev,
 						     ABS_MT_TOUCH_MAJOR,
-						     0, 255, 0, 0);
+						     0, features->x_max, 0, 0);
+				input_set_abs_params(input_dev,
+						     ABS_MT_TOUCH_MINOR,
+						     0, features->y_max, 0, 0);
 			}
 
 			input_set_abs_params(input_dev, ABS_MT_POSITION_X,