Input: wacom - add support for Bamboo Pen

This adds support for Pen on Bamboo Pen and Bamboo Pen&Touch devices.
Touchpad is handled by previous Bamboo Touch logic.
Signed-off-by: Chris Bagwell <chris@cnpbagwell.com>
Acked-by: Ping Cheng <pingc@wacom.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/tablet/wacom_wac.c

@@ -904,10 +904,75 @@ static int wacom_bpt_touch(struct wacom_wac *wacom)
 	return 0;
 }
 
+static int wacom_bpt_pen(struct wacom_wac *wacom)
+{
+	struct input_dev *input = wacom->input;
+	unsigned char *data = wacom->data;
+	int prox = 0, x = 0, y = 0, p = 0, d = 0, pen = 0, btn1 = 0, btn2 = 0;
+
+	/*
+	 * Similar to Graphire protocol, data[1] & 0x20 is proximity and
+	 * data[1] & 0x18 is tool ID.  0x30 is safety check to ignore
+	 * 2 unused tool ID's.
+	 */
+	prox = (data[1] & 0x30) == 0x30;
+
+	/*
+	 * All reports shared between PEN and RUBBER tool must be
+	 * forced to a known starting value (zero) when transitioning to
+	 * out-of-prox.
+	 *
+	 * If not reset then, to userspace, it will look like lost events
+	 * if new tool comes in-prox with same values as previous tool sent.
+	 *
+	 * Hardware does report zero in most out-of-prox cases but not all.
+	 */
+	if (prox) {
+		if (!wacom->shared->stylus_in_proximity) {
+			if (data[1] & 0x08) {
+				wacom->tool[0] = BTN_TOOL_RUBBER;
+				wacom->id[0] = ERASER_DEVICE_ID;
+			} else {
+				wacom->tool[0] = BTN_TOOL_PEN;
+				wacom->id[0] = STYLUS_DEVICE_ID;
+			}
+			wacom->shared->stylus_in_proximity = true;
+		}
+		x = le16_to_cpup((__le16 *)&data[2]);
+		y = le16_to_cpup((__le16 *)&data[4]);
+		p = le16_to_cpup((__le16 *)&data[6]);
+		d = data[8];
+		pen = data[1] & 0x01;
+		btn1 = data[1] & 0x02;
+		btn2 = data[1] & 0x04;
+	}
+
+	input_report_key(input, BTN_TOUCH, pen);
+	input_report_key(input, BTN_STYLUS, btn1);
+	input_report_key(input, BTN_STYLUS2, btn2);
+
+	input_report_abs(input, ABS_X, x);
+	input_report_abs(input, ABS_Y, y);
+	input_report_abs(input, ABS_PRESSURE, p);
+	input_report_abs(input, ABS_DISTANCE, d);
+
+	if (!prox) {
+		wacom->id[0] = 0;
+		wacom->shared->stylus_in_proximity = false;
+	}
+
+	input_report_key(input, wacom->tool[0], prox); /* PEN or RUBBER */
+	input_report_abs(input, ABS_MISC, wacom->id[0]); /* TOOL ID */
+
+	return 1;
+}
+
 static int wacom_bpt_irq(struct wacom_wac *wacom, size_t len)
 {
 	if (len == WACOM_PKGLEN_BBTOUCH)
 		return wacom_bpt_touch(wacom);
+	else if (len == WACOM_PKGLEN_BBFUN)
+		return wacom_bpt_pen(wacom);
 
 	return 0;
 }
@@ -1193,6 +1258,11 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 					     features->pressure_fuzz, 0);
 			input_set_abs_params(input_dev, ABS_MT_TRACKING_ID, 0,
 					     MAX_TRACKING_ID, 0, 0);
+		} else if (features->device_type == BTN_TOOL_PEN) {
+			__set_bit(BTN_TOOL_RUBBER, input_dev->keybit);
+			__set_bit(BTN_TOOL_PEN, input_dev->keybit);
+			__set_bit(BTN_STYLUS, input_dev->keybit);
+			__set_bit(BTN_STYLUS2, input_dev->keybit);
 		}
 		break;
 	}
@@ -1334,6 +1404,12 @@ static const struct wacom_features wacom_features_0x47 =
 	{ "Wacom Intuos2 6x8",    WACOM_PKGLEN_INTUOS,    20320, 16240, 1023, 31, INTUOS };
 static struct wacom_features wacom_features_0xD0 =
 	{ "Wacom Bamboo 2FG",     WACOM_PKGLEN_BBFUN,     14720,  9200, 1023, 63, BAMBOO_PT };
+static struct wacom_features wacom_features_0xD1 =
+	{ "Wacom Bamboo 2FG 4x5", WACOM_PKGLEN_BBFUN,     14720,  9200, 1023, 63, BAMBOO_PT };
+static struct wacom_features wacom_features_0xD2 =
+	{ "Wacom Bamboo Craft",   WACOM_PKGLEN_BBFUN,     14720,  9200, 1023, 63, BAMBOO_PT };
+static struct wacom_features wacom_features_0xD3 =
+	{ "Wacom Bamboo 2FG 6x8", WACOM_PKGLEN_BBFUN,     21648, 13530, 1023, 63, BAMBOO_PT };
 
 #define USB_DEVICE_WACOM(prod)					\
 	USB_DEVICE(USB_VENDOR_ID_WACOM, prod),			\
@@ -1399,6 +1475,9 @@ const struct usb_device_id wacom_ids[] = {
 	{ USB_DEVICE_WACOM(0xC7) },
 	{ USB_DEVICE_WACOM(0xCE) },
 	{ USB_DEVICE_WACOM(0xD0) },
+	{ USB_DEVICE_WACOM(0xD1) },
+	{ USB_DEVICE_WACOM(0xD2) },
+	{ USB_DEVICE_WACOM(0xD3) },
 	{ USB_DEVICE_WACOM(0xF0) },
 	{ USB_DEVICE_WACOM(0xCC) },
 	{ USB_DEVICE_WACOM(0x90) },