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iio: humidity: hdc3020: add power management

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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@gmail.com>
Link: https://lore.kernel.org/r/20240303-hdc3020-pm-v3-1-48bc02b5241b@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Javier Carrasco 2024-03-03 22:54:20 +01:00 committed by Jonathan Cameron
parent d1efcf8871
commit f764c293a1
1 changed files with 76 additions and 19 deletions
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95
drivers/iio/humidity/hdc3020.c
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@ -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, indio_dev);
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->lock);
@ -580,6 +621,20 @@ 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");
ret = devm_add_action_or_reset(&data->client->dev, hdc3020_exit, data);
if (ret)
return ret;
if (client->irq) {
ret = devm_request_threaded_irq(&client->dev, client->irq,
NULL, hdc3020_interrupt_handler,
@ -588,25 +643,8 @@ 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);
if (ret)
return ret;
ret = devm_iio_device_register(&data->client->dev, indio_dev);
if (ret)
return dev_err_probe(&client->dev, ret, "Failed to add device");
@ -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,