From: Balasubramani Vivekanandan <balasubramani_vivekanandan@xxxxxxxxxx>
In case of remote display, touch controller will be also remote.
In such cases, the reset pin of the touch controller will be
controlled through bridging ICs like Deserilizer and Serializer.
Therefore accessing the gpio pins require transactions with the
external IC. Using the function gpiod_set_value will print a
warning like below
WARNING: CPU: 0 PID: 576 at drivers/gpio/gpiolib.c:1441 gpiod_set_value+0x34/0x60()
CPU: 0 PID: 576 Comm: modprobe Not tainted 3.14.79-08377-g84ea22f-dirty #4
Backtrace:
[<80011c58>] (dump_backtrace) from [<80011e60>] (show_stack+0x18/0x1c)
[<80011e48>] (show_stack) from [<8052d7ac>] (dump_stack+0x7c/0x9c)
[<8052d730>] (dump_stack) from [<800241bc>] (warn_slowpath_common+0x74/0x9c)
[<80024148>] (warn_slowpath_common) from [<80024288>] (warn_slowpath_null+0x24/0x2c)
[<80024264>] (warn_slowpath_null) from [<8029e070>] (gpiod_set_value+0x34/0x60)
[<8029e03c>] (gpiod_set_value) from [<7f492e98>] (mxt_probe+0x1e0/0x718 [atmel_mxt_ts])
[<7f492cb8>] (mxt_probe [atmel_mxt_ts]) from [<803c4d34>] (i2c_device_probe+0xcc/0xec)
[<803c4c68>] (i2c_device_probe) from [<803252a0>] (driver_probe_device+0xc0/0x200)
Signed-off-by: Balasubramani Vivekanandan <balasubramani_vivekanandan@xxxxxxxxxx>
Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@xxxxxxxxxx>
Signed-off-by: Sanjeev Chugh <sanjeev_chugh@xxxxxxxxxx>
Signed-off-by: George G. Davis <george_davis@xxxxxxxxxx>
Signed-off-by: Jiada Wang <jiada_wang@xxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 700b7228e133..3e81e5d9175b 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -2490,7 +2490,7 @@ static void mxt_regulator_enable(struct mxt_data *data)
if (!data->reg_vdd || !data->reg_avdd)
return;
- gpiod_set_value(data->reset_gpio, 0);
+ gpiod_set_value_cansleep(data->reset_gpio, 0);
error = regulator_enable(data->reg_vdd);
if (error)
@@ -2508,7 +2508,7 @@ static void mxt_regulator_enable(struct mxt_data *data)
* voltage
*/
msleep(MXT_REGULATOR_DELAY);
- gpiod_set_value(data->reset_gpio, 1);
+ gpiod_set_value_cansleep(data->reset_gpio, 1);
msleep(MXT_CHG_DELAY);
retry_wait:
@@ -4313,7 +4313,7 @@ static int mxt_probe(struct i2c_client *client, const struct i2c_device_id *id)
disable_irq(data->irq);
} else if (data->reset_gpio) {
msleep(MXT_RESET_GPIO_TIME);
- gpiod_set_value(data->reset_gpio, 1);
+ gpiod_set_value_cansleep(data->reset_gpio, 1);
msleep(MXT_RESET_INVALID_CHG);
} else {
dev_dbg(&client->dev,
--
2.17.1
