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Message-Id: <20240220-hdc3020-pm-v1-4-d8e60dbe79e9@gmail.com>
Date: Tue, 20 Feb 2024 22:14:58 +0100
From: Javier Carrasco <javier.carrasco.cruz@...il.com>
To: Jonathan Cameron <jic23@...nel.org>,
Lars-Peter Clausen <lars@...afoo.de>, Li peiyu <579lpy@...il.com>,
Rob Herring <robh+dt@...nel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
Conor Dooley <conor+dt@...nel.org>
Cc: Jonathan Cameron <Jonathan.Cameron@...wei.com>,
linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org,
devicetree@...r.kernel.org,
Javier Carrasco <javier.carrasco.cruz@...il.com>
Subject: [PATCH 4/4] 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: Javier Carrasco <javier.carrasco.cruz@...il.com>
---
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 0da5c5c41cd2..bd2f57a7eedc 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
@@ -564,6 +566,11 @@ 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,
@@ -581,6 +588,9 @@ 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);
}
@@ -621,6 +631,12 @@ 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");
+
hdc3020_power_on(data);
if (client->irq) {
--
2.40.1
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