This series adds power management for the hdc3020 humidity and
temperature sensor as well as control over the reset signal the device
provides.
The hdc3020 carries out measurements automatically, which is not
necessary in low-power modes. Furthermore, if the low-power
configuration turns off the device, proper initialization is required to
account for the setup times and initial status register value.
This device provides an active low reset signal that must be handled if
connected. This signal can be used by the driver to keep the device
under minimal power consumption during low-power modes if the power
supply stays active.
This series uses char-misc-next as basis to include the last additions
to the driver to handle events [1] as well as the fix to include the
entries in the Makefile and Kconfig files [2].
[1] https://lore.kernel.org/linux-iio/[email protected]/
[2] https://lore.kernel.org/linux-iio/[email protected]/
Signed-off-by: Javier Carrasco <[email protected]>
---
Changes in v3:
- Drop unnecessary casting to void in dev_set_drvdata.
- Call devm_add_action_or_reset right after powering on.
- Link to v2: https://lore.kernel.org/r/[email protected]
Changes in v2:
- Trigger power off sequence if the power on sequence fails.
- Check return value of hdc3020_power_on() in the probe.
- Remove type casting for void pointer.
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Javier Carrasco (3):
iio: humidity: hdc3020: add power management
dt-bindings: iio: humidity: hdc3020: add reset-gpios
iio: humidity: hdc3020: add reset management
.../bindings/iio/humidity/ti,hdc3020.yaml | 5 +
drivers/iio/humidity/hdc3020.c | 111 +++++++++++++++++----
2 files changed, 97 insertions(+), 19 deletions(-)
---
base-commit: d4551c189d6e6a3fcf7f625bd4b273e770fad35a
change-id: 20240217-hdc3020-pm-177983de3cab
Best regards,
--
Javier Carrasco <[email protected]>
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 <[email protected]>
---
drivers/iio/humidity/hdc3020.c | 95 +++++++++++++++++++++++++++++++++---------
1 file changed, 76 insertions(+), 19 deletions(-)
diff --git a/drivers/iio/humidity/hdc3020.c b/drivers/iio/humidity/hdc3020.c
index 1e5d0d4797b1..7f93024b850c 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, 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,
--
2.40.1
The HDC3020 provides an active low reset signal that is still not
described in the bindings.
Add reset-gpios to the bindings and the example.
Reviewed-by: Krzysztof Kozlowski <[email protected]>
Signed-off-by: Javier Carrasco <[email protected]>
---
Documentation/devicetree/bindings/iio/humidity/ti,hdc3020.yaml | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/iio/humidity/ti,hdc3020.yaml b/Documentation/devicetree/bindings/iio/humidity/ti,hdc3020.yaml
index 8b5dedd1a598..b375d307513f 100644
--- a/Documentation/devicetree/bindings/iio/humidity/ti,hdc3020.yaml
+++ b/Documentation/devicetree/bindings/iio/humidity/ti,hdc3020.yaml
@@ -34,6 +34,9 @@ properties:
reg:
maxItems: 1
+ reset-gpios:
+ maxItems: 1
+
required:
- compatible
- reg
@@ -43,6 +46,7 @@ additionalProperties: false
examples:
- |
+ #include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/interrupt-controller/irq.h>
i2c {
#address-cells = <1>;
@@ -54,5 +58,6 @@ examples:
vdd-supply = <&vcc_3v3>;
interrupt-parent = <&gpio3>;
interrupts = <23 IRQ_TYPE_EDGE_RISING>;
+ reset-gpios = <&gpio3 27 GPIO_ACTIVE_LOW>;
};
};
--
2.40.1
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 <[email protected]>
---
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
On Sun, 03 Mar 2024 22:54:19 +0100
Javier Carrasco <[email protected]> wrote:
> This series adds power management for the hdc3020 humidity and
> temperature sensor as well as control over the reset signal the device
> provides.
>
> The hdc3020 carries out measurements automatically, which is not
> necessary in low-power modes. Furthermore, if the low-power
> configuration turns off the device, proper initialization is required to
> account for the setup times and initial status register value.
>
> This device provides an active low reset signal that must be handled if
> connected. This signal can be used by the driver to keep the device
> under minimal power consumption during low-power modes if the power
> supply stays active.
>
> This series uses char-misc-next as basis to include the last additions
> to the driver to handle events [1] as well as the fix to include the
> entries in the Makefile and Kconfig files [2].
>
> [1] https://lore.kernel.org/linux-iio/[email protected]/
> [2] https://lore.kernel.org/linux-iio/[email protected]/
>
> Signed-off-by: Javier Carrasco <[email protected]>
Applied to the togreg-normal branch of iio.git and pushed out for 0-day to
see what it can find. Note this is now 6.10 material and I'll be rebasing
on rc1 once available. It won't go into a tree next picks up until after that.
Thanks,
Jonathan
> ---
> Changes in v3:
> - Drop unnecessary casting to void in dev_set_drvdata.
> - Call devm_add_action_or_reset right after powering on.
> - Link to v2: https://lore.kernel.org/r/[email protected]
>
> Changes in v2:
> - Trigger power off sequence if the power on sequence fails.
> - Check return value of hdc3020_power_on() in the probe.
> - Remove type casting for void pointer.
> - Link to v1: https://lore.kernel.org/r/[email protected]
>
> ---
> Javier Carrasco (3):
> iio: humidity: hdc3020: add power management
> dt-bindings: iio: humidity: hdc3020: add reset-gpios
> iio: humidity: hdc3020: add reset management
>
> .../bindings/iio/humidity/ti,hdc3020.yaml | 5 +
> drivers/iio/humidity/hdc3020.c | 111 +++++++++++++++++----
> 2 files changed, 97 insertions(+), 19 deletions(-)
> ---
> base-commit: d4551c189d6e6a3fcf7f625bd4b273e770fad35a
> change-id: 20240217-hdc3020-pm-177983de3cab
>
> Best regards,