1 files changed, 35 insertions, 18 deletions

diff --git a/drivers/input/mouse/appletouch.c b/drivers/input/mouse/appletouch.c
index 36ebe5c25ee3..079816e6b23b 100644
--- a/drivers/input/mouse/appletouch.c
+++ b/drivers/input/mouse/appletouch.c
@@ -136,12 +136,28 @@ MODULE_DEVICE_TABLE(usb, atp_table);
 #define ATP_GEYSER_MODE_REQUEST_INDEX           0
 #define ATP_GEYSER_MODE_VENDOR_VALUE            0x04
 
+/**
+ * enum atp_status_bits - status bit meanings
+ *
+ * These constants represent the meaning of the status bits.
+ * (only Geyser 3/4)
+ *
+ * @ATP_STATUS_BUTTON: The button was pressed
+ * @ATP_STATUS_BASE_UPDATE: Update of the base values (untouched pad)
+ * @ATP_STATUS_FROM_RESET: Reset previously performed
+ */
+enum atp_status_bits {
+        ATP_STATUS_BUTTON       = BIT(0),
+        ATP_STATUS_BASE_UPDATE  = BIT(2),
+        ATP_STATUS_FROM_RESET   = BIT(4),
+};
+
 /* Structure to hold all of our device specific stuff */
 struct atp {
         char                    phys[64];
         struct usb_device       *udev;          /* usb device */
         struct urb              *urb;           /* usb request block */
-        signed char             *data;          /* transferred data */
+        u8                      *data;          /* transferred data */
         struct input_dev        *input;         /* input dev */
         enum atp_touchpad_type  type;           /* type of touchpad */
         bool                    open;
@@ -251,8 +267,6 @@ static void atp_reinit(struct work_struct *work)
         int retval;
 
         dprintk("appletouch: putting appletouch to sleep (reinit)\n");
-        dev->idlecount = 0;
-
         atp_geyser_init(udev);
 
         retval = usb_submit_urb(dev->urb, GFP_ATOMIC);
@@ -488,7 +502,7 @@ static void atp_complete_geyser_1_2(struct urb *urb)
                               ATP_XFACT, &x_z, &x_f);
         y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
                               ATP_YFACT, &y_z, &y_f);
-        key = dev->data[dev->datalen - 1] & 1;
+        key = dev->data[dev->datalen - 1] & ATP_STATUS_BUTTON;
 
         if (x && y) {
                 if (dev->x_old != -1) {
@@ -568,34 +582,38 @@ static void atp_complete_geyser_3_4(struct urb *urb)
 
         dbg_dump("sample", dev->xy_cur);
 
-        if (!dev->valid) {
-                /* first sample */
-                dev->valid = true;
-                dev->x_old = dev->y_old = -1;
-                memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
+        /* Just update the base values (i.e. touchpad in untouched state) */
+        if (dev->data[dev->datalen - 1] & ATP_STATUS_BASE_UPDATE) {
 
+                dprintk(KERN_DEBUG "appletouch: updated base values\n");
+
+                memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
                 goto exit;
         }
 
         for (i = 0; i < ATP_XSENSORS + ATP_YSENSORS; i++) {
-                /* accumulate the change */
-                signed char change = dev->xy_old[i] - dev->xy_cur[i];
-                dev->xy_acc[i] -= change;
+                /* calculate the change */
+                dev->xy_acc[i] = dev->xy_cur[i] - dev->xy_old[i];
+
+                /* this is a round-robin value, so couple with that */
+                if (dev->xy_acc[i] > 127)
+                        dev->xy_acc[i] -= 256;
+
+                if (dev->xy_acc[i] < -127)
+                        dev->xy_acc[i] += 256;
 
                 /* prevent down drifting */
                 if (dev->xy_acc[i] < 0)
                         dev->xy_acc[i] = 0;
         }
 
-        memcpy(dev->xy_old, dev->xy_cur, sizeof(dev->xy_old));
-
         dbg_dump("accumulator", dev->xy_acc);
 
         x = atp_calculate_abs(dev->xy_acc, ATP_XSENSORS,
                               ATP_XFACT, &x_z, &x_f);
         y = atp_calculate_abs(dev->xy_acc + ATP_XSENSORS, ATP_YSENSORS,
                               ATP_YFACT, &y_z, &y_f);
-        key = dev->data[dev->datalen - 1] & 1;
+        key = dev->data[dev->datalen - 1] & ATP_STATUS_BUTTON;
 
         if (x && y) {
                 if (dev->x_old != -1) {
@@ -647,7 +665,8 @@ static void atp_complete_geyser_3_4(struct urb *urb)
         if (!x && !y && !key) {
                 dev->idlecount++;
                 if (dev->idlecount == 10) {
-                        dev->valid = false;
+                        dev->x_old = dev->y_old = -1;
+                        dev->idlecount = 0;
                         schedule_work(&dev->work);
                         /* Don't resubmit urb here, wait for reinit */
                         return;
@@ -879,8 +898,6 @@ static int atp_suspend(struct usb_interface *iface, pm_message_t message)
         struct atp *dev = usb_get_intfdata(iface);
 
         usb_kill_urb(dev->urb);
-        dev->valid = false;
-
         return 0;
 }