input: edt-ft5x06: Only look at the number of points reported

Register 0x02 in the FT5x06 is TD_STATUS containing the number
of valid touch points being reported.

Iterate over that number of points rather than all that are
supported on the device.

Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>

diff --git a/drivers/input/touchscreen/edt-ft5x06.c b/drivers/input/touchscreen/edt-ft5x06.c
index f033496..719a5ad 100644 (file)
--- a/drivers/input/touchscreen/edt-ft5x06.c
+++ b/drivers/input/touchscreen/edt-ft5x06.c
@@ -205,6 +205,7 @@ static irqreturn_t edt_ft5x06_ts_isr(int irq, void *dev_id)
        unsigned int active_ids = 0, known_ids = tsdata->known_ids;
        long released_ids;
        int b = 0;
+       unsigned int num_points;
 
        switch (tsdata->version) {
        case EDT_M06:
@@ -252,9 +253,15 @@ static irqreturn_t edt_ft5x06_ts_isr(int irq, void *dev_id)
 
                if (!edt_ft5x06_ts_check_crc(tsdata, rdbuf, datalen))
                        goto out;
+               num_points = tsdata->max_support_points;
+       } else {
+               /* Register 2 is TD_STATUS, containing the number of touch
+                * points.
+                */
+               num_points = min(rdbuf[2] & 0xf, tsdata->max_support_points);
        }
 
-       for (i = 0; i < tsdata->max_support_points; i++) {
+       for (i = 0; i < num_points; i++) {
                u8 *buf = &rdbuf[i * tplen + offset];
 
                type = buf[0] >> 6;