As reported by the STEPCONFIG[1-16] registered field descriptions of the
TI reference manual, for the ADC "in single ended, SEL_INM_SWC_3_0 must
be 1xxx".

Unlike the Y and Z coordinates, this bit has not been set for the step
configuration registers used to sample the X coordinate.

Fixes: 1b8be32e691 ("Input: add support for TI Touchscreen controller")
Signed-off-by: Dario Binacchi <redacted>
---

(no changes since v1)

 drivers/input/touchscreen/ti_am335x_tsc.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/input/touchscreen/ti_am335x_tsc.c b/drivers/input/touchscreen/ti_am335x_tsc.c
index 83e685557a19..fd3ffdd23470 100644
--- a/drivers/input/touchscreen/ti_am335x_tsc.c
+++ b/drivers/input/touchscreen/ti_am335x_tsc.c

@@ -131,7 +131,8 @@ static void titsc_step_config(struct titsc *ts_dev)
 	u32 stepenable;
 
 	config = STEPCONFIG_MODE_HWSYNC |
-			STEPCONFIG_AVG_16 | ts_dev->bit_xp;
+			STEPCONFIG_AVG_16 | ts_dev->bit_xp |
+			STEPCONFIG_INM_ADCREFM;
 	switch (ts_dev->wires) {
 	case 4:
 		config |= STEPCONFIG_INP(ts_dev->inp_yp) | ts_dev->bit_xn;

-- 
2.17.1