[PATCH AUTOSEL for 4.9 001/219] Input: tsc2007 - check for presence and power down tsc2007 during probe

Sasha Levin
2018-03-04T00:10:18Z

From: "H. Nikolaus Schaller" <hns@goldelico.com>

[ 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@goldelico.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
drivers/input/touchscreen/tsc2007.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index 5d0cd51c6f41..a4b7b4c3d27b 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -455,6 +455,14 @@ static int tsc2007_probe(struct i2c_client *client,

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,
--
2.14.1