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Message-Id: <20240226-hdc3020-pm-v2-1-cec6766086e8@gmail.com>
Date: Mon, 26 Feb 2024 22:25:55 +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 v2 1/3] iio: humidity: hdc3020: add power management
The HDC3020 sensor carries out periodic measurements during normal
operation, but as long as the power supply is enabled, it will carry on
in low-power modes. In order to avoid that and reduce power consumption,
the device can be switched to Trigger-on Demand mode, and if possible,
turn off its regulator.
According to the datasheet, the maximum "Power Up Ready" is 5 ms.
Add resume/suspend pm operations to manage measurement mode and
regulator state.
Signed-off-by: Javier Carrasco <javier.carrasco.cruz@...il.com>
---
drivers/iio/humidity/hdc3020.c | 89 ++++++++++++++++++++++++++++++++++--------
1 file changed, 73 insertions(+), 16 deletions(-)
diff --git a/drivers/iio/humidity/hdc3020.c b/drivers/iio/humidity/hdc3020.c
index 1e5d0d4797b1..6848be41e1c8 100644
--- a/drivers/iio/humidity/hdc3020.c
+++ b/drivers/iio/humidity/hdc3020.c
@@ -20,6 +20,8 @@
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/mutex.h>
+#include <linux/pm.h>
+#include <linux/regulator/consumer.h>
#include <linux/units.h>
#include <asm/unaligned.h>
@@ -68,6 +70,7 @@
struct hdc3020_data {
struct i2c_client *client;
+ struct regulator *vdd_supply;
/*
* Ensure that the sensor configuration (currently only heater is
* supported) will not be changed during the process of reading
@@ -551,9 +554,45 @@ static const struct iio_info hdc3020_info = {
.write_event_value = hdc3020_write_thresh,
};
-static void hdc3020_stop(void *data)
+static int hdc3020_power_off(struct hdc3020_data *data)
{
- hdc3020_exec_cmd((struct hdc3020_data *)data, HDC3020_EXIT_AUTO);
+ hdc3020_exec_cmd(data, HDC3020_EXIT_AUTO);
+
+ return regulator_disable(data->vdd_supply);
+}
+
+static int hdc3020_power_on(struct hdc3020_data *data)
+{
+ int ret;
+
+ ret = regulator_enable(data->vdd_supply);
+ if (ret)
+ return ret;
+
+ fsleep(5000);
+
+ if (data->client->irq) {
+ /*
+ * The alert output is activated by default upon power up,
+ * hardware reset, and soft reset. Clear the status register.
+ */
+ ret = hdc3020_exec_cmd(data, HDC3020_S_STATUS);
+ if (ret) {
+ hdc3020_power_off(data);
+ return ret;
+ }
+ }
+
+ ret = hdc3020_exec_cmd(data, HDC3020_S_AUTO_10HZ_MOD0);
+ if (ret)
+ hdc3020_power_off(data);
+
+ return ret;
+}
+
+static void hdc3020_exit(void *data)
+{
+ hdc3020_power_off(data);
}
static int hdc3020_probe(struct i2c_client *client)
@@ -569,6 +608,8 @@ static int hdc3020_probe(struct i2c_client *client)
if (!indio_dev)
return -ENOMEM;
+ dev_set_drvdata(&client->dev, (void *)indio_dev);
+
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->lock);
@@ -580,6 +621,16 @@ static int hdc3020_probe(struct i2c_client *client)
indio_dev->info = &hdc3020_info;
indio_dev->channels = hdc3020_channels;
indio_dev->num_channels = ARRAY_SIZE(hdc3020_channels);
+
+ data->vdd_supply = devm_regulator_get(&client->dev, "vdd");
+ if (IS_ERR(data->vdd_supply))
+ return dev_err_probe(&client->dev, PTR_ERR(data->vdd_supply),
+ "Unable to get VDD regulator\n");
+
+ ret = hdc3020_power_on(data);
+ if (ret)
+ return dev_err_probe(&client->dev, ret, "Power on failed\n");
+
if (client->irq) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
NULL, hdc3020_interrupt_handler,
@@ -588,22 +639,9 @@ static int hdc3020_probe(struct i2c_client *client)
if (ret)
return dev_err_probe(&client->dev, ret,
"Failed to request IRQ\n");
-
- /*
- * The alert output is activated by default upon power up,
- * hardware reset, and soft reset. Clear the status register.
- */
- ret = hdc3020_exec_cmd(data, HDC3020_S_STATUS);
- if (ret)
- return ret;
}
- ret = hdc3020_exec_cmd(data, HDC3020_S_AUTO_10HZ_MOD0);
- if (ret)
- return dev_err_probe(&client->dev, ret,
- "Unable to set up measurement\n");
-
- ret = devm_add_action_or_reset(&data->client->dev, hdc3020_stop, data);
+ ret = devm_add_action_or_reset(&data->client->dev, hdc3020_exit, data);
if (ret)
return ret;
@@ -614,6 +652,24 @@ static int hdc3020_probe(struct i2c_client *client)
return 0;
}
+static int hdc3020_suspend(struct device *dev)
+{
+ struct iio_dev *iio_dev = dev_get_drvdata(dev);
+ struct hdc3020_data *data = iio_priv(iio_dev);
+
+ return hdc3020_power_off(data);
+}
+
+static int hdc3020_resume(struct device *dev)
+{
+ struct iio_dev *iio_dev = dev_get_drvdata(dev);
+ struct hdc3020_data *data = iio_priv(iio_dev);
+
+ return hdc3020_power_on(data);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(hdc3020_pm_ops, hdc3020_suspend, hdc3020_resume);
+
static const struct i2c_device_id hdc3020_id[] = {
{ "hdc3020" },
{ "hdc3021" },
@@ -633,6 +689,7 @@ MODULE_DEVICE_TABLE(of, hdc3020_dt_ids);
static struct i2c_driver hdc3020_driver = {
.driver = {
.name = "hdc3020",
+ .pm = pm_sleep_ptr(&hdc3020_pm_ops),
.of_match_table = hdc3020_dt_ids,
},
.probe = hdc3020_probe,
--
2.40.1
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