Commit e264b086 authored by Javier Carrasco's avatar Javier Carrasco Committed by Jonathan Cameron
Browse files

iio: humidity: hdc3020: add reset management 



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: default avatarJavier Carrasco <javier.carrasco.cruz@gmail.com>
Link: https://lore.kernel.org/r/20240303-hdc3020-pm-v3-3-48bc02b5241b@gmail.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
parent 137166ef

drivers/iio/humidity/hdc3020.c

+16 −0
Original line number Diff line number Diff line
@@ -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");