Input: ads7846 - don't check penirq immediately for 7845

[ Upstream commit fa9f4275b2 ]

To discard false readings, one should use "ti,penirq-recheck-delay-usecs".
Checking get_pendown_state() at the beginning, most of the time fails
causing malfunctioning.

Fixes: ffa458c1bd ("spi: ads7846 driver")
Signed-off-by: Luca Ellero <l.ellero@asem.it>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230126105227.47648-4-l.ellero@asem.it
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/input/touchscreen/ads7846.c

@@ -851,14 +851,8 @@ static void ads7846_report_state(struct ads7846 *ts)
 	if (x == MAX_12BIT)
 		x = 0;
 
-	if (ts->model == 7843) {
+	if (ts->model == 7843 || ts->model == 7845) {
 		Rt = ts->pressure_max / 2;
-	} else if (ts->model == 7845) {
-		if (get_pendown_state(ts))
-			Rt = ts->pressure_max / 2;
-		else
-			Rt = 0;
-		dev_vdbg(&ts->spi->dev, "x/y: %d/%d, PD %d\n", x, y, Rt);
 	} else if (likely(x && z1)) {
 		/* compute touch pressure resistance using equation #2 */
 		Rt = z2;