[PATCH v2 35/49] input: atmel_mxt_ts: Add Missing Delay for reset handling of Atmel touch panel controller in detachable displays.

From: Jiada Wang
Date: Tue Aug 27 2019 - 02:30:46 EST


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 35f41bfa70d5..192cf47ff5f4 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -4110,6 +4110,10 @@ 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);
--
2.19.2