Input: ALPS - make the V3 packet field decoder "pluggable"

A number of different ALPS touchpad protocols can reuse
alps_process_touchpad_packet_v3() with small tweaks to the bitfield
decoding.  Create a new priv->decode_fields() callback that handles the
per-model differences.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>
Tested-by: Dave Turvene <dturvene@dahetral.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

2 files changed, 95 insertions, 44 deletions

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 2cd8be774f91..270b7deefe5b 100644
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -447,17 +447,49 @@ static void alps_process_trackstick_packet_v3(struct psmouse *psmouse)
         return;
 }
 
+static void alps_decode_buttons_v3(struct alps_fields *f, unsigned char *p)
+{
+        f->left = !!(p[3] & 0x01);
+        f->right = !!(p[3] & 0x02);
+        f->middle = !!(p[3] & 0x04);
+
+        f->ts_left = !!(p[3] & 0x10);
+        f->ts_right = !!(p[3] & 0x20);
+        f->ts_middle = !!(p[3] & 0x40);
+}
+
+static void alps_decode_pinnacle(struct alps_fields *f, unsigned char *p)
+{
+        f->first_mp = !!(p[4] & 0x40);
+        f->is_mp = !!(p[0] & 0x40);
+
+        f->fingers = (p[5] & 0x3) + 1;
+        f->x_map = ((p[4] & 0x7e) << 8) |
+                   ((p[1] & 0x7f) << 2) |
+                   ((p[0] & 0x30) >> 4);
+        f->y_map = ((p[3] & 0x70) << 4) |
+                   ((p[2] & 0x7f) << 1) |
+                   (p[4] & 0x01);
+
+        f->x = ((p[1] & 0x7f) << 4) | ((p[4] & 0x30) >> 2) |
+               ((p[0] & 0x30) >> 4);
+        f->y = ((p[2] & 0x7f) << 4) | (p[4] & 0x0f);
+        f->z = p[5] & 0x7f;
+
+        alps_decode_buttons_v3(f, p);
+}
+
 static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
 {
         struct alps_data *priv = psmouse->private;
         unsigned char *packet = psmouse->packet;
         struct input_dev *dev = psmouse->dev;
         struct input_dev *dev2 = priv->dev2;
-        int x, y, z;
-        int left, right, middle;
         int x1 = 0, y1 = 0, x2 = 0, y2 = 0;
         int fingers = 0, bmap_fingers;
-        unsigned int x_bitmap, y_bitmap;
+        struct alps_fields f;
+
+        priv->decode_fields(&f, packet);
 
         /*
          * There's no single feature of touchpad position and bitmap packets
@@ -472,17 +504,10 @@ static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
                  * packet. Check for this, and when it happens process the
                  * position packet as usual.
                  */
-                if (packet[0] & 0x40) {
-                        fingers = (packet[5] & 0x3) + 1;
-                        x_bitmap = ((packet[4] & 0x7e) << 8) |
-                                   ((packet[1] & 0x7f) << 2) |
-                                   ((packet[0] & 0x30) >> 4);
-                        y_bitmap = ((packet[3] & 0x70) << 4) |
-                                   ((packet[2] & 0x7f) << 1) |
-                                   (packet[4] & 0x01);
-
+                if (f.is_mp) {
+                        fingers = f.fingers;
                         bmap_fingers = alps_process_bitmap(priv,
-                                                           x_bitmap, y_bitmap,
+                                                           f.x_map, f.y_map,
                                                            &x1, &y1, &x2, &y2);
 
                         /*
@@ -493,7 +518,7 @@ static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
                                 fingers = bmap_fingers;
 
                         /* Now process position packet */
-                        packet = priv->multi_data;
+                        priv->decode_fields(&f, priv->multi_data);
                 } else {
                         priv->multi_packet = 0;
                 }
@@ -507,10 +532,10 @@ static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
          * out misidentified bitmap packets, we reject anything with this
          * bit set.
          */
-        if (packet[0] & 0x40)
+        if (f.is_mp)
                 return;
 
-        if (!priv->multi_packet && (packet[4] & 0x40)) {
+        if (!priv->multi_packet && f.first_mp) {
                 priv->multi_packet = 1;
                 memcpy(priv->multi_data, packet, sizeof(priv->multi_data));
                 return;
@@ -518,22 +543,13 @@ static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
 
         priv->multi_packet = 0;
 
-        left = packet[3] & 0x01;
-        right = packet[3] & 0x02;
-        middle = packet[3] & 0x04;
-
-        x = ((packet[1] & 0x7f) << 4) | ((packet[4] & 0x30) >> 2) |
-            ((packet[0] & 0x30) >> 4);
-        y = ((packet[2] & 0x7f) << 4) | (packet[4] & 0x0f);
-        z = packet[5] & 0x7f;
-
         /*
          * Sometimes the hardware sends a single packet with z = 0
          * in the middle of a stream. Real releases generate packets
          * with x, y, and z all zero, so these seem to be flukes.
          * Ignore them.
          */
-        if (x && y && !z)
+        if (f.x && f.y && !f.z)
                 return;
 
         /*
@@ -541,12 +557,12 @@ static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
          * to rely on ST data.
          */
         if (!fingers) {
-                x1 = x;
-                y1 = y;
-                fingers = z > 0 ? 1 : 0;
+                x1 = f.x;
+                y1 = f.y;
+                fingers = f.z > 0 ? 1 : 0;
         }
 
-        if (z >= 64)
+        if (f.z >= 64)
                 input_report_key(dev, BTN_TOUCH, 1);
         else
                 input_report_key(dev, BTN_TOUCH, 0);
@@ -555,26 +571,22 @@ static void alps_process_touchpad_packet_v3(struct psmouse *psmouse)
 
         input_mt_report_finger_count(dev, fingers);
 
-        input_report_key(dev, BTN_LEFT, left);
-        input_report_key(dev, BTN_RIGHT, right);
-        input_report_key(dev, BTN_MIDDLE, middle);
+        input_report_key(dev, BTN_LEFT, f.left);
+        input_report_key(dev, BTN_RIGHT, f.right);
+        input_report_key(dev, BTN_MIDDLE, f.middle);
 
-        if (z > 0) {
-                input_report_abs(dev, ABS_X, x);
-                input_report_abs(dev, ABS_Y, y);
+        if (f.z > 0) {
+                input_report_abs(dev, ABS_X, f.x);
+                input_report_abs(dev, ABS_Y, f.y);
         }
-        input_report_abs(dev, ABS_PRESSURE, z);
+        input_report_abs(dev, ABS_PRESSURE, f.z);
 
         input_sync(dev);
 
         if (!(priv->quirks & ALPS_QUIRK_TRACKSTICK_BUTTONS)) {