[PATCH v7 34/48] input: atmel_mxt_ts: Add Missing Delay for reset handling of Atmel touch panel controller in detachable displays.

[Jiada Wang]

From: keerthikumarp <Keerthikumar.Padmanabha@xxxxxxxxxxxx>

In case of attached display, the touchpanel reset is controlled
via imx gpio's from  atmel driver and the delay between
touchpanel reset and the time at which the chip becomes capable to
communicate with the host processor, has be taken care.

However in case of detachable displays, the touchpanel reset is
controlled via a deserializer gpio which is triggered just before
the atmel driver is probed.The delay between touchpanel reset and
the time at which the chip becomes capable to communicate (as
specified in datasheet) was not being accounted for. This patch
introduces that delay.

Signed-off-by: keerthikumarp <Keerthikumar.Padmanabha@xxxxxxxxxxxx>
Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
---
 drivers/input/touchscreen/atmel_mxt_ts.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index b4ec565ee7dd..9f4212aedd11 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -4109,6 +4109,10 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		msleep(MXT_RESET_GPIO_TIME);
 		gpiod_set_value(data->reset_gpio, 1);
 		msleep(MXT_RESET_INVALID_CHG);
+	} else {
+		dev_dbg(&client->dev,
+			"atmel reset pin not found in device tree");
+		msleep(MXT_RESET_TIME);
 	}
 
 	error = mxt_initialize(data);
-- 
2.17.1