diff options
| -rw-r--r-- | drivers/input/mouse/synaptics.c | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/drivers/input/mouse/synaptics.c b/drivers/input/mouse/synaptics.c index a4b14a41cbf4..e2c2e1e2bd6f 100644 --- a/drivers/input/mouse/synaptics.c +++ b/drivers/input/mouse/synaptics.c @@ -40,11 +40,28 @@ * Note that newer firmware allows querying device for maximum useable * coordinates. */ +#define XMIN 0 +#define XMAX 6143 +#define YMIN 0 +#define YMAX 6143 #define XMIN_NOMINAL 1472 #define XMAX_NOMINAL 5472 #define YMIN_NOMINAL 1408 #define YMAX_NOMINAL 4448 +/* Size in bits of absolute position values reported by the hardware */ +#define ABS_POS_BITS 13 + +/* + * Any position values from the hardware above the following limits are + * treated as "wrapped around negative" values that have been truncated to + * the 13-bit reporting range of the hardware. These are just reasonable + * guesses and can be adjusted if hardware is found that operates outside + * of these parameters. + */ +#define X_MAX_POSITIVE (((1 << ABS_POS_BITS) + XMAX) / 2) +#define Y_MAX_POSITIVE (((1 << ABS_POS_BITS) + YMAX) / 2) + /* * Synaptics touchpads report the y coordinate from bottom to top, which is * opposite from what userspace expects. @@ -555,6 +572,12 @@ static int synaptics_parse_hw_state(const unsigned char buf[], hw->right = (buf[0] & 0x02) ? 1 : 0; } + /* Convert wrap-around values to negative */ + if (hw->x > X_MAX_POSITIVE) + hw->x -= 1 << ABS_POS_BITS; + if (hw->y > Y_MAX_POSITIVE) + hw->y -= 1 << ABS_POS_BITS; + return 0; } |