The HDC3020 provides an active low reset signal that must be handled if
connected. Asserting this signal turns the device into Trigger-on Demand
measurement mode, reducing its power consumption when no measurements
are required like in low-power modes.
According to the datasheet, the longest "Reset Ready" is 3 ms, which is
only taken into account if the reset signal is defined.
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@xxxxxxxxx>
---
drivers/iio/humidity/hdc3020.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/iio/humidity/hdc3020.c b/drivers/iio/humidity/hdc3020.c
index 7f93024b850c..cdc4789213ba 100644
--- a/drivers/iio/humidity/hdc3020.c
+++ b/drivers/iio/humidity/hdc3020.c
@@ -15,6 +15,7 @@
#include <linux/cleanup.h>
#include <linux/crc8.h>
#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
@@ -70,6 +71,7 @@
struct hdc3020_data {
struct i2c_client *client;
+ struct gpio_desc *reset_gpio;
struct regulator *vdd_supply;
/*
* Ensure that the sensor configuration (currently only heater is
@@ -558,6 +560,9 @@ static int hdc3020_power_off(struct hdc3020_data *data)
{
hdc3020_exec_cmd(data, HDC3020_EXIT_AUTO);
+ if (data->reset_gpio)
+ gpiod_set_value_cansleep(data->reset_gpio, 1);
+
return regulator_disable(data->vdd_supply);
}
@@ -571,6 +576,11 @@ static int hdc3020_power_on(struct hdc3020_data *data)
fsleep(5000);
+ if (data->reset_gpio) {
+ gpiod_set_value_cansleep(data->reset_gpio, 0);
+ fsleep(3000);
+ }
+
if (data->client->irq) {
/*
* The alert output is activated by default upon power up,
@@ -627,6 +637,12 @@ static int hdc3020_probe(struct i2c_client *client)
return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
"Unable to get VDD regulator\n");
+ data->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(data->reset_gpio))
+ return dev_err_probe(&client->dev, PTR_ERR(data->reset_gpio),
+ "Cannot get reset GPIO\n");
+
ret = hdc3020_power_on(data);
if (ret)
return dev_err_probe(&client->dev, ret, "Power on failed\n");
--
2.40.1
