Input: tsc2007 - check for presence and power down tsc2007 during probe
authorH. Nikolaus Schaller <hns@goldelico.com>
Fri, 17 Feb 2017 20:51:19 +0000 (12:51 -0800)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Fri, 17 Feb 2017 21:21:47 +0000 (13:21 -0800)
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>
drivers/input/touchscreen/tsc2007.c

index 5d0cd51c6f41d126beef0e6e4bc7580288129cf6..a4b7b4c3d27b29f0aae7286415ec6e3e9b5e44a7 100644 (file)
@@ -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,