[PATCH v4 3/8] drivers:input:tsc2007: check for presence and power down tsc2007 during probe

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 




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>
---
 drivers/input/touchscreen/tsc2007.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/input/touchscreen/tsc2007.c b/drivers/input/touchscreen/tsc2007.c
index e9d5086..c314331 100644
--- a/drivers/input/touchscreen/tsc2007.c
+++ b/drivers/input/touchscreen/tsc2007.c
@@ -538,6 +538,15 @@ 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);
+		iio_device_unregister(indio_dev);
+		return err;	/* usually, chip does not respond */
+	}
+
 	err = input_register_device(input_dev);
 	if (err) {
 		dev_err(&client->dev,
-- 
2.7.3

--
To unsubscribe from this list: send the line "unsubscribe devicetree" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Device Tree Compilter]     [Device Tree Spec]     [Linux Driver Backports]     [Video for Linux]     [Linux USB Devel]     [Linux PCI Devel]     [Linux Audio Users]     [Linux Kernel]     [Linux SCSI]     [XFree86]     [Yosemite Backpacking]
  Powered by Linux