4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: "H. Nikolaus Schaller" <hns@xxxxxxxxxxxxx>
[ Upstream commit 934df23171e7c5b71d937104d4957891c39748ff ]
1. check if chip is really present and don't succeed if it isn't.
2. if it succeeds, power down the chip until accessed
Signed-off-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/input/touchscreen/tsc2007.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -455,6 +455,14 @@ static int tsc2007_probe(struct i2c_clie
tsc2007_stop(ts);
+ /* power down the chip (TSC2007_SETUP does not ACK on I2C) */
+ err = tsc2007_xfer(ts, PWRDOWN);
+ if (err < 0) {
+ dev_err(&client->dev,
+ "Failed to setup chip: %d\n", err);
+ return err; /* usually, chip does not respond */
+ }
+
err = input_register_device(input_dev);
if (err) {
dev_err(&client->dev,