From: Douglas Anderson dianders@chromium.org
[ Upstream commit a85fbd6498441694475716a4d5c65f9d3e073faf ]
As can be seen in elants_i2c_power_off(), we want the reset GPIO asserted when power is off. The reset GPIO is active low so we need the reset line logic low when power is off to avoid leakage.
We have a problem, though, at probe time. At probe time we haven't powered the regulators on yet but we have:
devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_LOW);
While that _looks_ right, it turns out that it's not. The GPIOD_OUT_LOW doesn't mean to init the GPIO to low. It means init the GPIO to "not asserted". Since this is an active low GPIO that inits it to be high.
Let's fix this to properly init the GPIO. Now after both probe and power off the state of the GPIO is consistent (it's "asserted" or level low).
Once we fix this, we can see that at power on time we no longer to assert the reset GPIO as the first thing. The reset GPIO is _always_ asserted before powering on. Let's fix powering on to account for this.
Fixes: afe10358e47a ("Input: elants_i2c - wire up regulator support") Signed-off-by: Douglas Anderson dianders@chromium.org Link: https://lore.kernel.org/r/20221117123805.1.I9959ac561dd6e1e8e1ce7085e4de6167... Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/input/touchscreen/elants_i2c.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/input/touchscreen/elants_i2c.c b/drivers/input/touchscreen/elants_i2c.c index fd48fb6ef210..dc8eddefe7b0 100644 --- a/drivers/input/touchscreen/elants_i2c.c +++ b/drivers/input/touchscreen/elants_i2c.c @@ -1089,14 +1089,12 @@ static int elants_i2c_power_on(struct elants_data *ts) if (IS_ERR_OR_NULL(ts->reset_gpio)) return 0;
- gpiod_set_value_cansleep(ts->reset_gpio, 1); - error = regulator_enable(ts->vcc33); if (error) { dev_err(&ts->client->dev, "failed to enable vcc33 regulator: %d\n", error); - goto release_reset_gpio; + return error; }
error = regulator_enable(ts->vccio); @@ -1105,7 +1103,7 @@ static int elants_i2c_power_on(struct elants_data *ts) "failed to enable vccio regulator: %d\n", error); regulator_disable(ts->vcc33); - goto release_reset_gpio; + return error; }
/* @@ -1114,7 +1112,6 @@ static int elants_i2c_power_on(struct elants_data *ts) */ udelay(ELAN_POWERON_DELAY_USEC);
-release_reset_gpio: gpiod_set_value_cansleep(ts->reset_gpio, 0); if (error) return error; @@ -1222,7 +1219,7 @@ static int elants_i2c_probe(struct i2c_client *client, return error; }
- ts->reset_gpio = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_LOW); + ts->reset_gpio = devm_gpiod_get(&client->dev, "reset", GPIOD_OUT_HIGH); if (IS_ERR(ts->reset_gpio)) { error = PTR_ERR(ts->reset_gpio);