[PATCH 2/4 v2] input : wacom - retrieve maximum number of touch points

[Ping Cheng <pinglinux@gmail.com>]

>From the HID usage table when it is supported.

Tested-by: Chris Bagwell <chris@cnpbagwell.com>
Reviewed-by: Chris Bagwell <chris@cnpbagwell.com>
Signed-off-by: Ping Cheng <pingc@wacom.com>
---

v2: updated with Chris' comments.

 drivers/input/tablet/wacom_sys.c |   31 ++++++++++++++++++++++++++++++-
 drivers/input/tablet/wacom_wac.c |   10 ++++------
 drivers/input/tablet/wacom_wac.h |    1 +
 3 files changed, 35 insertions(+), 7 deletions(-)

diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index c9588ee..f7fe091 100644
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -28,6 +28,7 @@
 #define HID_USAGE_Y_TILT		0x3e
 #define HID_USAGE_FINGER		0x22
 #define HID_USAGE_STYLUS		0x20
+#define HID_USAGE_CONTACTMAX		0x55
 #define HID_COLLECTION			0xa1
 #define HID_COLLECTION_LOGICAL		0x02
 #define HID_COLLECTION_END		0xc0
@@ -191,11 +192,30 @@ static int wacom_parse_logical_collection(unsigned char *report,
 		features->x_max = features->y_max =
 			get_unaligned_le16(&report[10]);
 
+		features->touch_max = 16;
 		length = 11;
 	}
 	return length;
 }
 
+static void wacom_retrieve_report_data(struct usb_interface *intf,
+				       struct wacom_features *features)
+{
+	int result = 0;
+	unsigned char *rep_data;
+
+	rep_data = kmalloc(2, GFP_KERNEL);
+	if (!rep_data)
+		return;
+
+	rep_data[0] = 12;
+	result = wacom_get_report(intf, WAC_HID_FEATURE_REPORT,
+		 rep_data[0], rep_data, 2, WAC_MSG_RETRIES);
+
+	if ((result >= 0) && (rep_data[1] > 2))
+		features->touch_max = rep_data[1];
+}
+
 /*
  * Interface Descriptor of wacom devices can be incomplete and
  * inconsistent so wacom_features table is used to store stylus
@@ -286,16 +306,19 @@ static int wacom_parse_hid(struct usb_interface *intf,
 						if (features->type == TABLETPC2FG) {
 							/* need to reset back */
 							features->pktlen = WACOM_PKGLEN_TPC2FG;
+							features->touch_max = 2;
 						}
 						if (features->type == BAMBOO_PT) {
 							/* need to reset back */
 							features->pktlen = WACOM_PKGLEN_BBTOUCH;
+							features->touch_max = 2;
 							features->x_phy =
 								get_unaligned_le16(&report[i + 5]);
 							features->x_max =
 								get_unaligned_le16(&report[i + 8]);
 							i += 15;
 						} else {
+							features->touch_max = 1;
 							features->x_max =
 								get_unaligned_le16(&report[i + 3]);
 							features->x_phy =
@@ -369,6 +392,11 @@ static int wacom_parse_hid(struct usb_interface *intf,
 				pen = 1;
 				i++;
 				break;
+
+			case HID_USAGE_CONTACTMAX:
+				wacom_retrieve_report_data(intf, features);
+				i++;
+				break;
 			}
 			break;
 
@@ -873,7 +901,8 @@ static int wacom_probe(struct usb_interface *intf, const struct usb_device_id *i
 
 	endpoint = &intf->cur_altsetting->endpoint[0].desc;
 
-	/* Retrieve the physical and logical size for OEM devices */
+	/* Retrieve the physical and logical size for touch devices */
+	features->touch_max = 0;
 	error = wacom_retrieve_hid_descriptor(intf, features);
 	if (error)
 		goto fail3;
diff --git a/drivers/input/tablet/wacom_wac.c b/drivers/input/tablet/wacom_wac.c
index e18f362..33a4359 100644
--- a/drivers/input/tablet/wacom_wac.c
+++ b/drivers/input/tablet/wacom_wac.c
@@ -830,7 +830,8 @@ static int wacom_tpc_irq(struct wacom_wac *wacom, size_t len)
 {
 	char *data = wacom->data;
 
-	dbg("wacom_tpc_irq: received report #%d", data[0]);
+	dbg("wacom_tpc_irq: received report #%d with %d contacts",
+	     data[0], wacom->features.touch_max);
 
 	if (len == WACOM_PKGLEN_TPC1FG || data[0] == WACOM_REPORT_TPC1FG)
 		return wacom_tpc_single_touch(wacom, len);
@@ -1319,7 +1320,7 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 	case TABLETPC2FG:
 		if (features->device_type == BTN_TOOL_FINGER) {
 
-			input_mt_init_slots(input_dev, 2);
+			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);
 			input_set_abs_params(input_dev, ABS_MT_POSITION_X,
@@ -1374,6 +1375,7 @@ void 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);
 
 			if (features->pktlen == WACOM_PKGLEN_BBTOUCH3) {
 				__set_bit(BTN_TOOL_TRIPLETAP,
@@ -1381,13 +1383,9 @@ void wacom_setup_input_capabilities(struct input_dev *input_dev,
 				__set_bit(BTN_TOOL_QUADTAP,
 					  input_dev->keybit);
 
-				input_mt_init_slots(input_dev, 16);
-
 				input_set_abs_params(input_dev,
 						     ABS_MT_TOUCH_MAJOR,
 						     0, 255, 0, 0);
-			} else {
-				input_mt_init_slots(input_dev, 2);
 			}
 
 			input_set_abs_params(input_dev, ABS_MT_POSITION_X,
diff --git a/drivers/input/tablet/wacom_wac.h b/drivers/input/tablet/wacom_wac.h
index 050acae..6ddd2e4 100644
--- a/drivers/input/tablet/wacom_wac.h
+++ b/drivers/input/tablet/wacom_wac.h
@@ -89,6 +89,7 @@ struct wacom_features {
 	int pressure_fuzz;
 	int distance_fuzz;
 	unsigned quirks;
+	unsigned touch_max;
 };
 
 struct wacom_shared {
-- 
1.7.6.4