Input: wacom - make sure touch_max is set for touch devices

Old single touch Tablet PCs do not have touch_max set at
wacom_features. Since touch device at lease supports one
finger, assign touch_max to 1 when touch usage is defined
in its HID Descriptor and touch_max is not pre-defined.

Tested-by: Jason Gerecke <killertofu@gmail.com>
Signed-off-by: Ping Cheng <pingc@wacom.com>
Reviewed-by: Chris Bagwell <chris@cnpbagwell.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

1 files changed, 5 insertions, 2 deletions

diff --git a/drivers/input/tablet/wacom_sys.c b/drivers/input/tablet/wacom_sys.c
index 8a90da11365f..3d71b608330e 100644
--- a/drivers/input/tablet/wacom_sys.c
+++ b/drivers/input/tablet/wacom_sys.c
@@ -304,7 +304,7 @@ static int wacom_parse_hid(struct usb_interface *intf,
         struct usb_device *dev = interface_to_usbdev(intf);
         char limit = 0;
         /* result has to be defined as int for some devices */
-        int result = 0;
+        int result = 0, touch_max = 0;
         int i = 0, usage = WCM_UNDEFINED, finger = 0, pen = 0;
         unsigned char *report;
 
@@ -351,7 +351,8 @@ static int wacom_parse_hid(struct usb_interface *intf,
                                 if (usage == WCM_DESKTOP) {
                                         if (finger) {
                                                 features->device_type = BTN_TOOL_FINGER;
-
+                                                /* touch device at least supports one touch point */
+                                                touch_max = 1;
                                                 switch (features->type) {
                                                 case TABLETPC2FG:
                                                         features->pktlen = WACOM_PKGLEN_TPC2FG;
@@ -504,6 +505,8 @@ static int wacom_parse_hid(struct usb_interface *intf,
         }
 
  out:
+        if (!features->touch_max && touch_max)
+                features->touch_max = touch_max;
         result = 0;
         kfree(report);
         return result;