input: evdev: do centering adjustment

git-svn-id: file:///home/notaz/opt/svn/PicoDrive/platform@940 be3aeb3a-fb24-0410-a615-afba39da0efa

diff --git a/linux/in_evdev.c b/linux/in_evdev.c
index 7dd631e..23d2e2a 100644 (file)
--- a/linux/in_evdev.c
+++ b/linux/in_evdev.c
@@ -37,8 +37,8 @@ typedef struct {
        int kc_first;
        int kc_last;
        unsigned int abs_count;
-       /* 16.16 multiplier to IN_ABS_RANGE */
-       unsigned int abs_mult[MAX_ABS_DEVS];
+       int abs_mult[MAX_ABS_DEVS]; /* 16.16 multiplier to IN_ABS_RANGE */
+       int abs_adj[MAX_ABS_DEVS];  /* adjust for centering */
        unsigned int abs_to_digital:1;
 } in_evdev_t;
 
@@ -246,6 +246,7 @@ static void in_evdev_probe(void)
                                dist = ainfo.maximum - ainfo.minimum;
                                if (dist != 0)
                                        dev->abs_mult[u] = IN_ABS_RANGE * 2 * 65536 / dist;
+                               dev->abs_adj[u] = -(ainfo.maximum + ainfo.minimum + 1) / 2;
                                have_abs = 1;
                        }
                        dev->abs_count = u;
@@ -371,7 +372,8 @@ static int in_evdev_update_analog(void *drv_data, int axis_id, int *result)
        if (ret != 0)
                return ret;
 
-       *result = (int)(ainfo.value * dev->abs_mult[axis_id]) >> 16;
+       *result = (ainfo.value + dev->abs_adj[axis_id]) * dev->abs_mult[axis_id];
+       *result >>= 16;
        return 0;
 }