[PATCH 5.4 026/191] Input: st1232 - do not reset the chip too early

Greg Kroah-Hartman
2020-01-02T22:12:05Z

From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

[ Upstream commit efd7bb08a762d4f6322054c6824bd942971ac563 ]

We should not be putting the chip into reset while interrupts are enabled
and ISR may be running. Fix this by installing a custom devm action and
powering off the device/resetting GPIO line from there. This ensures proper
ordering.

Tested-by: Matthias Fend <Matthias.Fend@wolfvision.net>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/input/touchscreen/st1232.c | 22 ++++++++++++----------
1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/drivers/input/touchscreen/st1232.c b/drivers/input/touchscreen/st1232.c
index 1139714e72e2..1c5f8875cb79 100644
--- a/drivers/input/touchscreen/st1232.c
+++ b/drivers/input/touchscreen/st1232.c
@@ -149,6 +149,11 @@ static void st1232_ts_power(struct st1232_ts_data *ts, bool poweron)
gpiod_set_value_cansleep(ts->reset_gpio, !poweron);
}

+static void st1232_ts_power_off(void *data)
+{
+ st1232_ts_power(data, false);
+}
+
static const struct st_chip_info st1232_chip_info = {
.have_z = true,
.max_x = 0x31f, /* 800 - 1 */
@@ -229,6 +234,13 @@ static int st1232_ts_probe(struct i2c_client *client,

st1232_ts_power(ts, true);

+ error = devm_add_action_or_reset(&client->dev, st1232_ts_power_off, ts);
+ if (error) {
+ dev_err(&client->dev,
+ "Failed to install power off action: %d\n", error);
+ return error;
+ }
+
input_dev->name = "st1232-touchscreen";
input_dev->id.bustype = BUS_I2C;
input_dev->dev.parent = &client->dev;
@@ -271,15 +283,6 @@ static int st1232_ts_probe(struct i2c_client *client,
return 0;
}

-static int st1232_ts_remove(struct i2c_client *client)
-{
- struct st1232_ts_data *ts = i2c_get_clientdata(client);
-
- st1232_ts_power(ts, false);
-
- return 0;
-}
-
static int __maybe_unused st1232_ts_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
@@ -329,7 +332,6 @@ MODULE_DEVICE_TABLE(of, st1232_ts_dt_ids);

static struct i2c_driver st1232_ts_driver = {
.probe = st1232_ts_probe,
- .remove = st1232_ts_remove,
.id_table = st1232_ts_id,
.driver = {
.name = ST1232_TS_NAME,
--
2.20.1