[PATCH] input: Add support for eGalax TouchKit USB touchscreen used on HP tx1305us

[Alastair Bridgewater <nyef@lisphacker.com>]

The eGalax touchscreen used in the HP tx1305us tablet PC (and presumably 
the rest of the tx1000 series) uses a different format for events from 
the device than the existing driver supports.

Add a new device description and interrupt packet handler for the 
touchscreen used in the tx1305us, claiming the USB device ID for the 
device that this patch was tested with from the older eGalax device code.

Signed-off-by: Alastair Bridgewater <nyef@lisphacker.com>

---

Applies clean with linux-2.6.25 and linux-2.6.26-rc6.

--- linux-2.6.26-rc6/drivers/input/touchscreen/usbtouchscreen.c   
 2008-06-27 20:34:34.886969800 -0400
+++ linux-2.6.25/drivers/input/touchscreen/usbtouchscreen.c   
 2008-06-06 12:19:16.460568440 -0400
@@ -103,6 +103,7 @@ struct usbtouch_usb {
 enum {
     DEVTPYE_DUMMY = -1,
     DEVTYPE_EGALAX,
+    DEVTYPE_EGALAX2,
     DEVTYPE_PANJIT,
     DEVTYPE_3M,
     DEVTYPE_ITM,
@@ -120,7 +121,7 @@ static struct usb_device_id usbtouch_dev
     {USB_DEVICE(0x3823, 0x0001), .driver_info = DEVTYPE_EGALAX},
     {USB_DEVICE(0x3823, 0x0002), .driver_info = DEVTYPE_EGALAX},
     {USB_DEVICE(0x0123, 0x0001), .driver_info = DEVTYPE_EGALAX},
-    {USB_DEVICE(0x0eef, 0x0001), .driver_info = DEVTYPE_EGALAX},
+    {USB_DEVICE(0x0eef, 0x0001), .driver_info = DEVTYPE_EGALAX2},
     {USB_DEVICE(0x0eef, 0x0002), .driver_info = DEVTYPE_EGALAX},
     {USB_DEVICE(0x1234, 0x0001), .driver_info = DEVTYPE_EGALAX},
     {USB_DEVICE(0x1234, 0x0002), .driver_info = DEVTYPE_EGALAX},
@@ -217,6 +218,15 @@ static int egalax_get_pkt_len(unsigned c
 
     return 0;
 }
+
+static int egalax2_read_data(struct usbtouch_usb *dev, unsigned char *pkt)
+{
+    dev->x = ((pkt[3] & 0x0F) << 8) | pkt[2];
+    dev->y = ((pkt[5] & 0x0F) << 8) | pkt[4];
+    dev->touch = pkt[1] & 0x01;
+
+    return 1;
+}
 #endif
 
 
@@ -555,6 +565,15 @@ static struct usbtouch_device_info usbto
         .get_pkt_len    = egalax_get_pkt_len,
         .read_data    = egalax_read_data,
     },
+
+    [DEVTYPE_EGALAX2] = {
+        .min_xc        = 0x0,
+        .max_xc        = 0x0fff,
+        .min_yc        = 0x0,
+        .max_yc        = 0x0fff,
+        .rept_size    = 8,
+        .read_data    = egalax2_read_data,
+    },
 #endif
 
 #ifdef CONFIG_TOUCHSCREEN_USB_PANJIT