[PATCH 2/2] input: wacom - add 0xE5 (MT device) support

[Ping Cheng <pinglinux@gmail.com>]

Main part of patch is adding support for a new Wacom MT touch
packet and labels these devices using MTSCREEN type.

Other items of interest:

Delete some duplicate code in HID parsing for Y info since
its already done in X path.

In wacom_query_tablet_data(), only invoke the set report
that requests tablets to send Wacom Touch packets for
Finger interfaces.  Mostly, this is to make code intent clear.

Tested-by: Jason Gerecke <killertofu@gmail.com>
Signed-off-by: Chris Bagwell <chris@cnpbagwell.com>
Signed-off-by: Ping Cheng <pingc@wacom.com>
---
 drivers/input/tablet/wacom.h     |    4 +-
 drivers/input/tablet/wacom_sys.c |   86 +++++++++++++++++++---------------
 drivers/input/tablet/wacom_wac.c |   96 ++++++++++++++++++++++++++++++++++++--
 drivers/input/tablet/wacom_wac.h |    8 +++
 4 files changed, 149 insertions(+), 45 deletions(-)

diff --git a/drivers/input/tablet/wacom.h b/drivers/input/tablet/wacom.h
index b4842d0..b79d451 100644
--- a/drivers/input/tablet/wacom.h
+++ b/drivers/input/tablet/wacom.h
@@ -135,6 +135,6 @@ extern const struct usb_device_id wacom_ids[];
 
 void wacom_wac_irq(struct wacom_wac *wacom_wac, size_t len);
 void wacom_setup_device_quirks(struct wacom_features *features);
-void wacom_setup_input_capabilities(struct input_dev *input_dev,
-				    struct wacom_wac *wacom_wac);
+int wacom_setup_input_capabilities(struct input_dev *input_dev,
+				   struct wacom_wac *wacom_wac);
 #endif
diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index 347026b..a941d6e 100644
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -317,6 +317,10 @@ static int wacom_parse_hid(struct usb_interface *intf,
 							/* need to reset back */
 							features->pktlen = WACOM_PKGLEN_TPC2FG;
 						}
+
+						if (features->type == MTSCREEN)
+							features->pktlen = WACOM_PKGLEN_MTOUCH;
+
 						if (features->type == BAMBOO_PT) {
 							/* need to reset back */
 							features->pktlen = WACOM_PKGLEN_BBTOUCH;
@@ -349,18 +353,15 @@ static int wacom_parse_hid(struct usb_interface *intf,
 			case HID_USAGE_Y:
 				if (usage == WCM_DESKTOP) {
 					if (finger) {
-						features->device_type = BTN_TOOL_FINGER;
-						if (features->type == TABLETPC2FG) {
-							/* need to reset back */
-							features->pktlen = WACOM_PKGLEN_TPC2FG;
+						int type = features->type;
+
+						if (type == TABLETPC2FG || type == MTSCREEN) {
 							features->y_max =
 								get_unaligned_le16(&report[i + 3]);
 							features->y_phy =
 								get_unaligned_le16(&report[i + 6]);
 							i += 7;
-						} else if (features->type == BAMBOO_PT) {
-							/* need to reset back */
-							features->pktlen = WACOM_PKGLEN_BBTOUCH;
+						} else if (type == BAMBOO_PT) {
 							features->y_phy =
 								get_unaligned_le16(&report[i + 3]);
 							features->y_max =
@@ -374,10 +375,6 @@ static int wacom_parse_hid(struct usb_interface *intf,
 							i += 4;
 						}
 					} else if (pen) {
-						/* penabled only accepts exact bytes of data */
-						if (features->type == TABLETPC2FG)
-							features->pktlen = WACOM_PKGLEN_GRAPHIRE;
-						features->device_type = BTN_TOOL_PEN;
 						features->y_max =
 							get_unaligned_le16(&report[i + 3]);
 						i += 4;
@@ -440,22 +437,27 @@ static int wacom_query_tablet_data(struct usb_interface *intf, struct wacom_feat
 	if (!rep_data)
 		return error;
 
-	/* ask to report tablet data if it is MT Tablet PC or
-	 * not a Tablet PC */
-	if (features->type == TABLETPC2FG) {
-		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);
+	/* ask to report Wacom data */
+	if (features->device_type == BTN_TOOL_FINGER) {
+		/* if it is an MT Tablet PC touch */
+		if ((features->type == TABLETPC2FG) ||
+		    (features->type == MTSCREEN)) {
+			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);
+		}
 	} else if (features->type != TABLETPC &&
 		   features->type != WIRELESS &&
 		   features->device_type == BTN_TOOL_PEN) {
@@ -466,8 +468,8 @@ static int wacom_query_tablet_data(struct usb_interface *intf, struct wacom_feat
 						 report_id, rep_data, 2, 1);
 			if (error >= 0)
 				error = wacom_get_report(intf,
-						WAC_HID_FEATURE_REPORT,
-						report_id, rep_data, 2, 1);
+							 WAC_HID_FEATURE_REPORT,
+							 report_id, rep_data, 2, 1);
 		} while ((error < 0 || rep_data[1] != 2) && limit++ < WAC_MSG_RETRIES);
 	}
 
@@ -505,9 +507,9 @@ static int wacom_retrieve_hid_descriptor(struct usb_interface *intf,
 		}
 	}
 
-	/* only Tablet PCs and Bamboo P&T need to retrieve the info */
+	/* only devices that support touch need to retrieve the info */
 	if ((features->type != TABLETPC) && (features->type != TABLETPC2FG) &&
-	    (features->type != BAMBOO_PT))
+	    (features->type != BAMBOO_PT) && (features->type != MTSCREEN))
 		goto out;
 
 	if (usb_get_extra_descriptor(interface, HID_DEVICET_HID, &hid_desc)) {
@@ -978,8 +980,10 @@ static int wacom_register_input(struct wacom *wacom)
 	int error;
 
 	input_dev = input_allocate_device();
-	if (!input_dev)
-		return -ENOMEM;
+	if (!input_dev) {
+		error = -ENOMEM;
+		goto fail1;
+	}
 
 	input_dev->name = wacom_wac->name;
 	input_dev->dev.parent = &intf->dev;
@@ -989,14 +993,20 @@ static int wacom_register_input(struct wacom *wacom)
 	input_set_drvdata(input_dev, wacom);
 
 	wacom_wac->input = input_dev;
-	wacom_setup_input_capabilities(input_dev, wacom_wac);
+	error = wacom_setup_input_capabilities(input_dev, wacom_wac);
+	if (error)
+		goto fail1;
 
 	error = input_register_device(input_dev);
-	if (error) {
-		input_free_device(input_dev);
-		wacom_wac->input = NULL;
-	}
+	if (error)
+		goto fail2;
+
+	return 0;
 
+fail2:
+	input_free_device(input_dev);
+	wacom_wac->input = NULL;
+fail1:
 	return error;
 }
 
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index e5cd0e5..3afd3bc 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -768,6 +768,70 @@ static int wacom_intuos_irq(struct wacom_wac *wacom)
 	return 1;
 }
 
+static int find_slot_from_contactid(struct wacom_wac *wacom, int contactid)
+{
+	int touch_max = wacom->features.touch_max;
+	int i;
+
+	if (!wacom->slots)
+		return -1;
+
+	for (i = 0; i < touch_max; ++i) {
+		if (wacom->slots[i] == contactid)
+			return i;
+	}
+	for (i = 0; i < touch_max; ++i) {
+		if (wacom->slots[i] == -1)
+			return i;
+	}
+	return -1;
+}
+
+static int wacom_mt_touch(struct wacom_wac *wacom)
+{
+	struct input_dev *input = wacom->input;
+	char *data = wacom->data;
+	int i;
+	int current_num_contacts = data[2];
+	int contacts_to_send = 0;
+
+	/* reset the counter by the first packet since only the first
+	 * packet in series will have non-zero current_num_contacts
+	 */
+	if (current_num_contacts)
+		wacom->num_contacts_left = current_num_contacts;
+
+	/* There are at most 5 contacts per packet */
+	contacts_to_send = min(5, (int)wacom->num_contacts_left);
+
+	for (i = 0; i < contacts_to_send; i++) {
+		int offset = (WACOM_BYTES_PER_MT_PACKET * i) + 3;
+		bool touch = data[offset] & 0x1;
+		int id = le16_to_cpup((__le16 *)&data[offset + 1]);
+		int slot = find_slot_from_contactid(wacom, id);
+
+		if (slot < 0)
+			continue;
+
+		input_mt_slot(input, slot);
+		input_mt_report_slot_state(input, MT_TOOL_FINGER, touch);
+		if (touch) {
+			int x = le16_to_cpup((__le16 *)&data[offset + 7]);
+			int y = le16_to_cpup((__le16 *)&data[offset + 9]);
+			input_report_abs(input, ABS_MT_POSITION_X, x);
+			input_report_abs(input, ABS_MT_POSITION_Y, y);
+		}
+		wacom->slots[slot] = touch ? id : -1;
+	}
+
+	input_mt_report_pointer_emulation(input, true);
+
+	wacom->num_contacts_left -= contacts_to_send;
+	if (wacom->num_contacts_left < 0)
+		wacom->num_contacts_left = 0;
+	return 1;
+}
+
 static int wacom_tpc_mt_touch(struct wacom_wac *wacom)
 {
 	struct input_dev *input = wacom->input;
@@ -806,6 +870,10 @@ static int wacom_tpc_single_touch(struct wacom_wac *wacom, size_t len)
 	bool prox;
 	int x = 0, y = 0;
 
+	if ((wacom->features.touch_max > 1) ||
+				(len > WACOM_PKGLEN_TPC2FG))
+		return 0;
+
 	if (!wacom->shared->stylus_in_proximity) {
 		if (len == WACOM_PKGLEN_TPC1FG) {
 			prox = data[0] & 0x01;
@@ -873,10 +941,10 @@ static int wacom_tpc_irq(struct wacom_wac *wacom, size_t len)
 
 	switch (len) {
 	case WACOM_PKGLEN_TPC1FG:
-		 return wacom_tpc_single_touch(wacom, len);
+		return wacom_tpc_single_touch(wacom, len);
 
 	case WACOM_PKGLEN_TPC2FG:
- 		return wacom_tpc_mt_touch(wacom);
+		return wacom_tpc_mt_touch(wacom);
 
 	default:
 		switch (data[0]) {
@@ -885,6 +953,9 @@ static int wacom_tpc_irq(struct wacom_wac *wacom, size_t len)
 		case WACOM_REPORT_TPCST:
 			return wacom_tpc_single_touch(wacom, len);
 
+		case WACOM_REPORT_TPCMT:
+			return wacom_mt_touch(wacom);
+
 		case WACOM_REPORT_PENABLED:
 			return wacom_tpc_pen(wacom);
 		}
@@ -1164,6 +1235,7 @@ void wacom_wac_irq(struct wacom_wac *wacom_wac, size_t len)
 
 	case TABLETPC:
 	case TABLETPC2FG:
+	case MTSCREEN:
 		sync = wacom_tpc_irq(wacom_wac, len);
 		break;
 
@@ -1237,7 +1309,8 @@ void wacom_setup_device_quirks(struct wacom_features *features)
 	/* these device have multiple inputs */
 	if (features->type == TABLETPC || features->type == TABLETPC2FG ||
 	    features->type == BAMBOO_PT || features->type == WIRELESS ||
-	    (features->type >= INTUOS5S && features->type <= INTUOS5L))
+	    (features->type >= INTUOS5S && features->type <= INTUOS5L) ||
+	    features->type == MTSCREEN)
 		features->quirks |= WACOM_QUIRK_MULTI_INPUT;
 
 	/* quirk for bamboo touch with 2 low res touches */
@@ -1268,8 +1341,8 @@ static unsigned int wacom_calculate_touch_res(unsigned int logical_max,
        return (logical_max * 100) / physical_max;
 }
 
-void wacom_setup_input_capabilities(struct input_dev *input_dev,
-				    struct wacom_wac *wacom_wac)
+int wacom_setup_input_capabilities(struct input_dev *input_dev,
+				   struct wacom_wac *wacom_wac)
 {
 	struct wacom_features *features = &wacom_wac->features;
 	int i;
@@ -1465,8 +1538,16 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 		break;
 
 	case TABLETPC2FG:
+	case MTSCREEN:
 		if (features->device_type == BTN_TOOL_FINGER) {
 
+			wacom_wac->slots = kmalloc(features->touch_max *
+						   sizeof(int), GFP_KERNEL);
+			if (!wacom_wac->slots)
+				return -ENOMEM;
+			for (i = 0; i < features->touch_max; i++)
+				wacom_wac->slots[i] = -1;
+
 			input_mt_init_slots(input_dev, features->touch_max);
 			input_set_abs_params(input_dev, ABS_MT_TOOL_TYPE,
 					0, MT_TOOL_MAX, 0, 0);
@@ -1552,6 +1633,7 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 		}
 		break;
 	}
+	return 0;
 }
 
 static const struct wacom_features wacom_features_0x00 =
@@ -1784,6 +1866,9 @@ static const struct wacom_features wacom_features_0xE3 =
 	{ "Wacom ISDv4 E3",       WACOM_PKGLEN_TPC2FG,    26202, 16325,  255,
 	  0, TABLETPC2FG, WACOM_INTUOS_RES, WACOM_INTUOS_RES,
 	  .touch_max = 2 };
+static const struct wacom_features wacom_features_0xE5 =
+	{ "Wacom ISDv4 E5",       WACOM_PKGLEN_MTOUCH,    26202, 16325,  255,
+	  0, MTSCREEN, WACOM_INTUOS_RES, WACOM_INTUOS_RES };
 static const struct wacom_features wacom_features_0xE6 =
 	{ "Wacom ISDv4 E6",       WACOM_PKGLEN_TPC2FG,    27760, 15694,  255,
 	  0, TABLETPC2FG, WACOM_INTUOS_RES, WACOM_INTUOS_RES,
@@ -1962,6 +2047,7 @@ const struct usb_device_id wacom_ids[] = {
 	{ USB_DEVICE_WACOM(0x9F) },
 	{ USB_DEVICE_WACOM(0xE2) },
 	{ USB_DEVICE_WACOM(0xE3) },
+	{ USB_DEVICE_WACOM(0xE5) },
 	{ USB_DEVICE_WACOM(0xE6) },
 	{ USB_DEVICE_WACOM(0xEC) },
 	{ USB_DEVICE_WACOM(0x47) },
diff --git a/drivers/input/tablet/wacom_wac.h b/drivers/input/tablet/wacom_wac.h
index 321269c..3dde639 100644
--- a/drivers/input/tablet/wacom_wac.h
+++ b/drivers/input/tablet/wacom_wac.h
@@ -25,6 +25,10 @@
 #define WACOM_PKGLEN_BBTOUCH3	64
 #define WACOM_PKGLEN_BBPEN	10
 #define WACOM_PKGLEN_WIRELESS	32
+#define WACOM_PKGLEN_MTOUCH	62
+
+/* wacom data size per MT contact */
+#define WACOM_BYTES_PER_MT_PACKET	11
 
 /* device IDs */
 #define STYLUS_DEVICE_ID	0x02
@@ -41,6 +45,7 @@
 #define WACOM_REPORT_INTUOS5PAD		3
 #define WACOM_REPORT_TPC1FG		6
 #define WACOM_REPORT_TPC2FG		13
+#define WACOM_REPORT_TPCMT		13
 #define WACOM_REPORT_TPCHID		15
 #define WACOM_REPORT_TPCST		16
 
@@ -76,6 +81,7 @@ enum {
 	WACOM_MO,
 	TABLETPC,
 	TABLETPC2FG,
+	MTSCREEN,
 	MAX_TYPE
 };
 
@@ -118,6 +124,8 @@ struct wacom_wac {
 	struct input_dev *input;
 	int pid;
 	int battery_capacity;
+	unsigned num_contacts_left;
+	int *slots;
 };
 
 #endif
-- 
1.7.5.4