[PATCH] HID: wacom: Report correct device resolution when using the wireless adapater

[Jason Gerecke <killertofu@gmail.com>]

The 'wacom_wireless_work' function does not recalculate the tablet's
resolution, causing the value contained in the 'features' struct to
always be reported to userspace. This value is valid only for the pen
interface, meaning that the value will be incorrect for the touchpad (if
present). This in particular causes problems for libinput which relies
on the reported resolution being correct.

This patch adds the necessary calls to recalculate the resolution for
each interface. This requires a little bit of code shuffling since both
the 'wacom_set_default_phy' and 'wacom_calculate_res' are declared below
their new first point of use in 'wacom_wireless_work'.

Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
---
Jiri: Would it be possible to target this patch for 4.2?

 drivers/hid/wacom_sys.c | 70 ++++++++++++++++++++++++++-----------------------
 1 file changed, 37 insertions(+), 33 deletions(-)

diff --git a/drivers/hid/wacom_sys.c b/drivers/hid/wacom_sys.c
index 4c0ffca..7e064b0 100644
--- a/drivers/hid/wacom_sys.c
+++ b/drivers/hid/wacom_sys.c
@@ -1282,6 +1282,39 @@ fail_register_pen_input:
 	return error;
 }
 
+/*
+ * Not all devices report physical dimensions from HID.
+ * Compute the default from hardcoded logical dimension
+ * and resolution before driver overwrites them.
+ */
+static void wacom_set_default_phy(struct wacom_features *features)
+{
+	if (features->x_resolution) {
+		features->x_phy = (features->x_max * 100) /
+					features->x_resolution;
+		features->y_phy = (features->y_max * 100) /
+					features->y_resolution;
+	}
+}
+
+static void wacom_calculate_res(struct wacom_features *features)
+{
+	/* set unit to "100th of a mm" for devices not reported by HID */
+	if (!features->unit) {
+		features->unit = 0x11;
+		features->unitExpo = -3;
+	}
+
+	features->x_resolution = wacom_calc_hid_res(features->x_max,
+						    features->x_phy,
+						    features->unit,
+						    features->unitExpo);
+	features->y_resolution = wacom_calc_hid_res(features->y_max,
+						    features->y_phy,
+						    features->unit,
+						    features->unitExpo);
+}
+
 static void wacom_wireless_work(struct work_struct *work)
 {
 	struct wacom *wacom = container_of(work, struct wacom, work);
@@ -1339,6 +1372,8 @@ static void wacom_wireless_work(struct work_struct *work)
 		if (wacom_wac1->features.type != INTUOSHT &&
 		    wacom_wac1->features.type != BAMBOO_PT)
 			wacom_wac1->features.device_type |= WACOM_DEVICETYPE_PAD;
+		wacom_set_default_phy(&wacom_wac1->features);
+		wacom_calculate_res(&wacom_wac1->features);
 		snprintf(wacom_wac1->pen_name, WACOM_NAME_MAX, "%s (WL) Pen",
 			 wacom_wac1->features.name);
 		snprintf(wacom_wac1->pad_name, WACOM_NAME_MAX, "%s (WL) Pad",
@@ -1357,7 +1392,9 @@ static void wacom_wireless_work(struct work_struct *work)
 			wacom_wac2->features =
 				*((struct wacom_features *)id->driver_data);
 			wacom_wac2->features.pktlen = WACOM_PKGLEN_BBTOUCH3;
+			wacom_set_default_phy(&wacom_wac2->features);
 			wacom_wac2->features.x_max = wacom_wac2->features.y_max = 4096;
+			wacom_calculate_res(&wacom_wac2->features);
 			snprintf(wacom_wac2->touch_name, WACOM_NAME_MAX,
 				 "%s (WL) Finger",wacom_wac2->features.name);
 			snprintf(wacom_wac2->pad_name, WACOM_NAME_MAX,
@@ -1405,39 +1442,6 @@ void wacom_battery_work(struct work_struct *work)
 	}
 }
 
-/*
- * Not all devices report physical dimensions from HID.
- * Compute the default from hardcoded logical dimension
- * and resolution before driver overwrites them.
- */
-static void wacom_set_default_phy(struct wacom_features *features)
-{
-	if (features->x_resolution) {
-		features->x_phy = (features->x_max * 100) /
-					features->x_resolution;
-		features->y_phy = (features->y_max * 100) /
-					features->y_resolution;
-	}
-}
-
-static void wacom_calculate_res(struct wacom_features *features)
-{
-	/* set unit to "100th of a mm" for devices not reported by HID */
-	if (!features->unit) {
-		features->unit = 0x11;
-		features->unitExpo = -3;
-	}
-
-	features->x_resolution = wacom_calc_hid_res(features->x_max,
-						    features->x_phy,
-						    features->unit,
-						    features->unitExpo);
-	features->y_resolution = wacom_calc_hid_res(features->y_max,
-						    features->y_phy,
-						    features->unit,
-						    features->unitExpo);
-}
-
 static size_t wacom_compute_pktlen(struct hid_device *hdev)
 {
 	struct hid_report_enum *report_enum;
-- 
2.5.0