HID: wacom: generic: Add support for sensor offsets

Many of Wacom's display tablets include an "outbound" area where pen
digitizing is possible but outside of the display area. To accommodate
such sensors in the HID_GENERIC codepath, we add support for the
necessary vendor-defined HID feature usages and adjust the min/max
values of the X and Y axes accordingly, similar to what is done in
the non-generic codepath.
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/wacom_sys.c

@@ -122,6 +122,7 @@ static void wacom_feature_mapping(struct hid_device *hdev,
 	struct hid_data *hid_data = &wacom->wacom_wac.hid_data;
 	u8 *data;
 	int ret;
+	int n;
 
 	switch (usage->hid) {
 	case HID_DG_CONTACTMAX:
@@ -180,6 +181,27 @@ static void wacom_feature_mapping(struct hid_device *hdev,
 			wacom->wacom_wac.mode_value = 0;
 		}
 		break;
+	case WACOM_HID_WD_OFFSETLEFT:
+	case WACOM_HID_WD_OFFSETTOP:
+	case WACOM_HID_WD_OFFSETRIGHT:
+	case WACOM_HID_WD_OFFSETBOTTOM:
+		/* read manually */
+		n = hid_report_len(field->report);
+		data = hid_alloc_report_buf(field->report, GFP_KERNEL);
+		if (!data)
+			break;
+		data[0] = field->report->id;
+		ret = wacom_get_report(hdev, HID_FEATURE_REPORT,
+					data, n, WAC_CMD_RETRIES);
+		if (ret == n) {
+			ret = hid_report_raw_event(hdev, HID_FEATURE_REPORT,
+						   data, n, 0);
+		} else {
+			hid_warn(hdev, "%s: could not retrieve sensor offsets\n",
+				 __func__);
+		}
+		kfree(data);
+		break;
 	}
 }
 
@@ -718,11 +740,6 @@ static int wacom_add_shared_data(struct hid_device *hdev)
 		return retval;
 	}
 
-	if (wacom_wac->features.device_type & WACOM_DEVICETYPE_TOUCH)
-		wacom_wac->shared->touch = hdev;
-	else if (wacom_wac->features.device_type & WACOM_DEVICETYPE_PEN)
-		wacom_wac->shared->pen = hdev;
-
 out:
 	mutex_unlock(&wacom_udev_list_lock);
 	return retval;
@@ -2019,6 +2036,10 @@ static int wacom_parse_and_register(struct wacom *wacom, bool wireless)
 	if (error)
 		goto fail;
 
+	error = wacom_add_shared_data(hdev);
+	if (error)
+		goto fail;
+
 	/*
 	 * Bamboo Pad has a generic hid handling for the Pen, and we switch it
 	 * into debug mode for the touch part.
@@ -2059,9 +2080,10 @@ static int wacom_parse_and_register(struct wacom *wacom, bool wireless)
 
 	wacom_update_name(wacom, wireless ? " (WL)" : "");
 
-	error = wacom_add_shared_data(hdev);
-	if (error)
-		goto fail;
+	if (wacom_wac->features.device_type & WACOM_DEVICETYPE_TOUCH)
+		wacom_wac->shared->touch = hdev;
+	else if (wacom_wac->features.device_type & WACOM_DEVICETYPE_PEN)
+		wacom_wac->shared->pen = hdev;
 
 	if (!(features->device_type & WACOM_DEVICETYPE_WL_MONITOR) &&
 	     (features->quirks & WACOM_QUIRK_BATTERY)) {

drivers/hid/wacom_wac.c

@@ -1468,6 +1468,9 @@ static int wacom_equivalent_usage(int usage)
 static void wacom_map_usage(struct input_dev *input, struct hid_usage *usage,
 		struct hid_field *field, __u8 type, __u16 code, int fuzz)
 {
+	struct wacom *wacom = input_get_drvdata(input);
+	struct wacom_wac *wacom_wac = &wacom->wacom_wac;
+	struct wacom_features *features = &wacom_wac->features;
 	int fmin = field->logical_minimum;
 	int fmax = field->logical_maximum;
 	unsigned int equivalent_usage = wacom_equivalent_usage(usage->hid);
@@ -1477,6 +1480,15 @@ static void wacom_map_usage(struct input_dev *input, struct hid_usage *usage,
 		resolution_code = ABS_RZ;
 	}
 
+	if (equivalent_usage == HID_GD_X) {
+		fmin += features->offset_left;
+		fmax -= features->offset_right;
+	}
+	if (equivalent_usage == HID_GD_Y) {
+		fmin += features->offset_top;
+		fmax -= features->offset_bottom;
+	}
+
 	usage->type = type;
 	usage->code = code;
 
@@ -1629,6 +1641,34 @@ static int wacom_wac_pen_event(struct hid_device *hdev, struct hid_field *field,
 		 */
 		wacom_wac->id[0] |= value;
 		return 0;
+	case WACOM_HID_WD_OFFSETLEFT:
+		if (features->offset_left && value != features->offset_left)
+			hid_warn(hdev, "%s: overriding exising left offset "
+				 "%d -> %d\n", __func__, value,
+				 features->offset_left);
+		features->offset_left = value;
+		return 0;
+	case WACOM_HID_WD_OFFSETRIGHT:
+		if (features->offset_right && value != features->offset_right)
+			hid_warn(hdev, "%s: overriding exising right offset "
+				 "%d -> %d\n", __func__, value,
+				 features->offset_right);
+		features->offset_right = value;
+		return 0;
+	case WACOM_HID_WD_OFFSETTOP:
+		if (features->offset_top && value != features->offset_top)
+			hid_warn(hdev, "%s: overriding exising top offset "
+				 "%d -> %d\n", __func__, value,
+				 features->offset_top);
+		features->offset_top = value;
+		return 0;
+	case WACOM_HID_WD_OFFSETBOTTOM:
+		if (features->offset_bottom && value != features->offset_bottom)
+			hid_warn(hdev, "%s: overriding exising bottom offset "
+				 "%d -> %d\n", __func__, value,
+				 features->offset_bottom);
+		features->offset_bottom = value;
+		return 0;
 	}
 
 	/* send pen events only when touch is up or forced out

drivers/hid/wacom_wac.h

@@ -94,6 +94,10 @@
 #define WACOM_HID_WD_TOOLTYPE           (WACOM_HID_UP_WACOMDIGITIZER | 0x77)
 #define WACOM_HID_WD_DISTANCE           (WACOM_HID_UP_WACOMDIGITIZER | 0x0132)
 #define WACOM_HID_WD_FINGERWHEEL        (WACOM_HID_UP_WACOMDIGITIZER | 0x0d03)
+#define WACOM_HID_WD_OFFSETLEFT         (WACOM_HID_UP_WACOMDIGITIZER | 0x0d30)
+#define WACOM_HID_WD_OFFSETTOP          (WACOM_HID_UP_WACOMDIGITIZER | 0x0d31)
+#define WACOM_HID_WD_OFFSETRIGHT        (WACOM_HID_UP_WACOMDIGITIZER | 0x0d32)
+#define WACOM_HID_WD_OFFSETBOTTOM       (WACOM_HID_UP_WACOMDIGITIZER | 0x0d33)
 #define WACOM_HID_WD_DATAMODE           (WACOM_HID_UP_WACOMDIGITIZER | 0x1002)
 #define WACOM_HID_UP_G9                 0xff090000
 #define WACOM_HID_G9_PEN                (WACOM_HID_UP_G9 | 0x02)