Input: alps - only set fields that are actually present

Pinnacle / Rushmore packets contain either position info, or bitmap info,
never both. So far we've in essence been storing garbage in the position /
bitmap fields of the fields struct when decoding a bitmap / pos packet.

We've been relying on the following sequence to get away with this:

1) Decode bitmap packet
2) Process bitmap packet
3) Decode position packet
4) Use position / button info

This patch allows us to change this sequence, which will allow using the
position info when processing the bitmap for more accurate results.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index f4ba73b..942ee08 100644 (file)
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -576,20 +576,22 @@ static int 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->st.x = ((p[1] & 0x7f) << 4) | ((p[4] & 0x30) >> 2) |
-              ((p[0] & 0x30) >> 4);
-       f->st.y = ((p[2] & 0x7f) << 4) | (p[4] & 0x0f);
-       f->pressure = p[5] & 0x7f;
+       if (f->is_mp) {
+               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);
+       } else {
+               f->st.x = ((p[1] & 0x7f) << 4) | ((p[4] & 0x30) >> 2) |
+                      ((p[0] & 0x30) >> 4);
+               f->st.y = ((p[2] & 0x7f) << 4) | (p[4] & 0x0f);
+               f->pressure = p[5] & 0x7f;
 
-       alps_decode_buttons_v3(f, p);
+               alps_decode_buttons_v3(f, p);
+       }
 
        return 0;
 }
@@ -600,22 +602,24 @@ static int alps_decode_rushmore(struct alps_fields *f, unsigned char *p,
        f->first_mp = !!(p[4] & 0x40);
        f->is_mp = !!(p[5] & 0x40);
 
-       f->fingers = max((p[5] & 0x3), ((p[5] >> 2) & 0x3)) + 1;
-       f->x_map = ((p[5] & 0x10) << 11) |
-                  ((p[4] & 0x7e) << 8) |
-                  ((p[1] & 0x7f) << 2) |
-                  ((p[0] & 0x30) >> 4);
-       f->y_map = ((p[5] & 0x20) << 6) |
-                  ((p[3] & 0x70) << 4) |
-                  ((p[2] & 0x7f) << 1) |
-                  (p[4] & 0x01);
-
-       f->st.x = ((p[1] & 0x7f) << 4) | ((p[4] & 0x30) >> 2) |
-              ((p[0] & 0x30) >> 4);
-       f->st.y = ((p[2] & 0x7f) << 4) | (p[4] & 0x0f);
-       f->pressure = p[5] & 0x7f;
-
-       alps_decode_buttons_v3(f, p);
+       if (f->is_mp) {
+               f->fingers = max((p[5] & 0x3), ((p[5] >> 2) & 0x3)) + 1;
+               f->x_map = ((p[5] & 0x10) << 11) |
+                          ((p[4] & 0x7e) << 8) |
+                          ((p[1] & 0x7f) << 2) |
+                          ((p[0] & 0x30) >> 4);
+               f->y_map = ((p[5] & 0x20) << 6) |
+                          ((p[3] & 0x70) << 4) |
+                          ((p[2] & 0x7f) << 1) |
+                          (p[4] & 0x01);
+       } else {
+               f->st.x = ((p[1] & 0x7f) << 4) | ((p[4] & 0x30) >> 2) |
+                      ((p[0] & 0x30) >> 4);
+               f->st.y = ((p[2] & 0x7f) << 4) | (p[4] & 0x0f);
+               f->pressure = p[5] & 0x7f;
+
+               alps_decode_buttons_v3(f, p);
+       }
 
        return 0;
 }