[PATCH v3 1/3] iio: temperature: mlx90632 Add runtime powermanagement modes

From: cmo
Date: Tue Sep 06 2022 - 05:05:06 EST

From: Crt Mori <cmo@xxxxxxxxxxx>

The sensor can operate in lower power modes and even make measurements when
in those lower powered modes. The decision was taken that if measurement
is not requested within 2 seconds the sensor will remain in SLEEP_STEP
power mode, where measurements are triggered on request with setting the
start of measurement bit (SOB). In this mode the measurements are taking
a bit longer because we need to start it and complete it. Currently, in
continuous mode we read ready data and this mode is activated if sensor
measurement is requested within 2 seconds. The suspend timeout is
increased to 6 seconds (instead of 3 before), because that enables more
measurements in lower power mode (SLEEP_STEP), with the lowest refresh
rate (2 seconds).

Signed-off-by: Crt Mori <cmo@xxxxxxxxxxx>
---
drivers/iio/temperature/mlx90632.c | 347 +++++++++++++++++++++++++----
1 file changed, 302 insertions(+), 45 deletions(-)

diff --git a/drivers/iio/temperature/mlx90632.c b/drivers/iio/temperature/mlx90632.c
index 549c0ab5c2be..e41a18edbc65 100644
--- a/drivers/iio/temperature/mlx90632.c
+++ b/drivers/iio/temperature/mlx90632.c
@@ -6,11 +6,14 @@
*
* Driver for the Melexis MLX90632 I2C 16-bit IR thermopile sensor
*/
+#include <linux/bitfield.h>
#include <linux/delay.h>
+#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/iopoll.h>
+#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/limits.h>
#include <linux/mod_devicetable.h>
@@ -55,6 +58,12 @@
#define MLX90632_EE_Ha 0x2481 /* Ha customer calib value reg 16bit */
#define MLX90632_EE_Hb 0x2482 /* Hb customer calib value reg 16bit */

+#define MLX90632_EE_MEDICAL_MEAS1 0x24E1 /* Medical measurement 1 16bit */
+#define MLX90632_EE_MEDICAL_MEAS2 0x24E2 /* Medical measurement 2 16bit */
+#define MLX90632_EE_EXTENDED_MEAS1 0x24F1 /* Extended measurement 1 16bit */
+#define MLX90632_EE_EXTENDED_MEAS2 0x24F2 /* Extended measurement 2 16bit */
+#define MLX90632_EE_EXTENDED_MEAS3 0x24F3 /* Extended measurement 3 16bit */
+
/* Register addresses - volatile */
#define MLX90632_REG_I2C_ADDR 0x3000 /* Chip I2C address register */

@@ -62,13 +71,16 @@
#define MLX90632_REG_CONTROL 0x3001 /* Control Register address */
#define MLX90632_CFG_PWR_MASK GENMASK(2, 1) /* PowerMode Mask */
#define MLX90632_CFG_MTYP_MASK GENMASK(8, 4) /* Meas select Mask */
+#define MLX90632_CFG_SOB_MASK BIT(11)

/* PowerModes statuses */
#define MLX90632_PWR_STATUS(ctrl_val) (ctrl_val << 1)
#define MLX90632_PWR_STATUS_HALT MLX90632_PWR_STATUS(0) /* hold */
-#define MLX90632_PWR_STATUS_SLEEP_STEP MLX90632_PWR_STATUS(1) /* sleep step*/
+#define MLX90632_PWR_STATUS_SLEEP_STEP MLX90632_PWR_STATUS(1) /* sleep step */
#define MLX90632_PWR_STATUS_STEP MLX90632_PWR_STATUS(2) /* step */
-#define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous*/
+#define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous */
+
+#define MLX90632_EE_RR GENMASK(10, 8) /* Only Refresh Rate bits */

/* Measurement types */
#define MLX90632_MTYP_MEDICAL 0
@@ -116,8 +128,9 @@
#define MLX90632_REF_12 12LL /* ResCtrlRef value of Ch 1 or Ch 2 */
#define MLX90632_REF_3 12LL /* ResCtrlRef value of Channel 3 */
#define MLX90632_MAX_MEAS_NUM 31 /* Maximum measurements in list */
-#define MLX90632_SLEEP_DELAY_MS 3000 /* Autosleep delay */
+#define MLX90632_SLEEP_DELAY_MS 6000 /* Autosleep delay */
#define MLX90632_EXTENDED_LIMIT 27000 /* Extended mode raw value limit */
+#define MLX90632_MEAS_MAX_TIME 2000 /* Max measurement time in ms for the lowest refresh rate */

/**
* struct mlx90632_data - private data for the MLX90632 device
@@ -130,6 +143,9 @@
* @object_ambient_temperature: Ambient temperature at object (might differ of
* the ambient temperature of sensor.
* @regulator: Regulator of the device
+ * @powerstatus: Current POWER status of the device
+ * @interaction_ts: Timestamp of the last temperature read that is used
+ * for power management in jiffies
*/
struct mlx90632_data {
struct i2c_client *client;
@@ -139,6 +155,8 @@ struct mlx90632_data {
u8 mtyp;
u32 object_ambient_temperature;
struct regulator *regulator;
+ int powerstatus;
+ unsigned long interaction_ts;
};

static const struct regmap_range mlx90632_volatile_reg_range[] = {
@@ -158,6 +176,8 @@ static const struct regmap_range mlx90632_read_reg_range[] = {
regmap_reg_range(MLX90632_EE_VERSION, MLX90632_EE_Ka),
regmap_reg_range(MLX90632_EE_CTRL, MLX90632_EE_I2C_ADDR),
regmap_reg_range(MLX90632_EE_Ha, MLX90632_EE_Hb),
+ regmap_reg_range(MLX90632_EE_MEDICAL_MEAS1, MLX90632_EE_MEDICAL_MEAS2),
+ regmap_reg_range(MLX90632_EE_EXTENDED_MEAS1, MLX90632_EE_EXTENDED_MEAS3),
regmap_reg_range(MLX90632_REG_I2C_ADDR, MLX90632_REG_CONTROL),
regmap_reg_range(MLX90632_REG_I2C_CMD, MLX90632_REG_I2C_CMD),
regmap_reg_range(MLX90632_REG_STATUS, MLX90632_REG_STATUS),
@@ -198,16 +218,38 @@ static const struct regmap_config mlx90632_regmap = {

static s32 mlx90632_pwr_set_sleep_step(struct regmap *regmap)
{
- return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
- MLX90632_CFG_PWR_MASK,
- MLX90632_PWR_STATUS_SLEEP_STEP);
+ struct mlx90632_data *data =
+ iio_priv(dev_get_drvdata(regmap_get_device(regmap)));
+ s32 ret;
+
+ if (data->powerstatus == MLX90632_PWR_STATUS_SLEEP_STEP)
+ return 0;
+
+ ret = regmap_write_bits(regmap, MLX90632_REG_CONTROL, MLX90632_CFG_PWR_MASK,
+ MLX90632_PWR_STATUS_SLEEP_STEP);
+ if (ret < 0)
+ return ret;
+
+ data->powerstatus = MLX90632_PWR_STATUS_SLEEP_STEP;
+ return ret;
}

static s32 mlx90632_pwr_continuous(struct regmap *regmap)
{
- return regmap_update_bits(regmap, MLX90632_REG_CONTROL,
- MLX90632_CFG_PWR_MASK,
- MLX90632_PWR_STATUS_CONTINUOUS);
+ struct mlx90632_data *data =
+ iio_priv(dev_get_drvdata(regmap_get_device(regmap)));
+ s32 ret;
+
+ if (data->powerstatus == MLX90632_PWR_STATUS_CONTINUOUS)
+ return 0;
+
+ ret = regmap_write_bits(regmap, MLX90632_REG_CONTROL, MLX90632_CFG_PWR_MASK,
+ MLX90632_PWR_STATUS_CONTINUOUS);
+ if (ret < 0)
+ return ret;
+
+ data->powerstatus = MLX90632_PWR_STATUS_CONTINUOUS;
+ return ret;
}

/**
@@ -219,6 +261,63 @@ static void mlx90632_reset_delay(void)
usleep_range(150, 200);
}

+static int mlx90632_get_measurement_time(struct regmap *regmap, u16 meas)
+{
+ unsigned int reg;
+ int ret;
+
+ ret = regmap_read(regmap, meas, &reg);
+ if (ret < 0)
+ return ret;
+
+ return MLX90632_MEAS_MAX_TIME >> FIELD_GET(MLX90632_EE_RR, reg);
+}
+
+static int mlx90632_calculate_dataset_ready_time(struct mlx90632_data *data)
+{
+ unsigned int refresh_time;
+ int ret;
+
+ if (data->mtyp == MLX90632_MTYP_MEDICAL) {
+ ret = mlx90632_get_measurement_time(data->regmap,
+ MLX90632_EE_MEDICAL_MEAS1);
+ if (ret < 0)
+ return ret;
+
+ refresh_time = ret;
+
+ ret = mlx90632_get_measurement_time(data->regmap,
+ MLX90632_EE_MEDICAL_MEAS2);
+ if (ret < 0)
+ return ret;
+
+ refresh_time += ret;
+ } else {
+ ret = mlx90632_get_measurement_time(data->regmap,
+ MLX90632_EE_EXTENDED_MEAS1);
+ if (ret < 0)
+ return ret;
+
+ refresh_time = ret;
+
+ ret = mlx90632_get_measurement_time(data->regmap,
+ MLX90632_EE_EXTENDED_MEAS2);
+ if (ret < 0)
+ return ret;
+
+ refresh_time += ret;
+
+ ret = mlx90632_get_measurement_time(data->regmap,
+ MLX90632_EE_EXTENDED_MEAS3);
+ if (ret < 0)
+ return ret;
+
+ refresh_time += ret;
+ }
+
+ return refresh_time;
+}
+
/**
* mlx90632_perform_measurement() - Trigger and retrieve current measurement cycle
* @data: pointer to mlx90632_data object containing regmap information
@@ -249,26 +348,76 @@ static int mlx90632_perform_measurement(struct mlx90632_data *data)
return (reg_status & MLX90632_STAT_CYCLE_POS) >> 2;
}

-static int mlx90632_set_meas_type(struct regmap *regmap, u8 type)
+/**
+ * mlx90632_perform_measurement_burst() - Trigger and retrieve current measurement
+ * cycle in step sleep mode
+ * @data: pointer to mlx90632_data object containing regmap information
+ *
+ * Perform a measurement and return 2 as measurement cycle position reported
+ * by sensor. This is a blocking function for amount dependent on the sensor
+ * refresh rate.
+ */
+static int mlx90632_perform_measurement_burst(struct mlx90632_data *data)
{
+ unsigned int reg_status;
int ret;

- if ((type != MLX90632_MTYP_MEDICAL) && (type != MLX90632_MTYP_EXTENDED))
- return -EINVAL;
+ ret = regmap_write_bits(data->regmap, MLX90632_REG_CONTROL,
+ MLX90632_CFG_SOB_MASK, MLX90632_CFG_SOB_MASK);
+ if (ret < 0)
+ return ret;
+
+ ret = mlx90632_calculate_dataset_ready_time(data);
+ if (ret < 0)
+ return ret;
+
+ msleep(ret); /* Wait minimum time for dataset to be ready */
+
+ ret = regmap_read_poll_timeout(data->regmap, MLX90632_REG_STATUS,
+ reg_status,
+ (reg_status & MLX90632_STAT_BUSY) == 0,
+ 10000, 100 * 10000);
+ if (ret < 0) {
+ dev_err(&data->client->dev, "data not ready");
+ return -ETIMEDOUT;
+ }
+
+ return 2;
+}
+
+
+static int mlx90632_set_meas_type(struct mlx90632_data *data, u8 type)
+{
+ int current_powerstatus;
+ int ret;
+
+ if (data->mtyp == type)
+ return 0;

- ret = regmap_write(regmap, MLX90632_REG_I2C_CMD, MLX90632_RESET_CMD);
+ current_powerstatus = data->powerstatus;
+ ret = mlx90632_pwr_continuous(data->regmap);
+ if (ret < 0)
+ return ret;
+
+ ret = regmap_write(data->regmap, MLX90632_REG_I2C_CMD, MLX90632_RESET_CMD);
if (ret < 0)
return ret;

mlx90632_reset_delay();

- ret = regmap_write_bits(regmap, MLX90632_REG_CONTROL,
+ ret = regmap_update_bits(data->regmap, MLX90632_REG_CONTROL,
(MLX90632_CFG_MTYP_MASK | MLX90632_CFG_PWR_MASK),
(MLX90632_MTYP_STATUS(type) | MLX90632_PWR_STATUS_HALT));
if (ret < 0)
return ret;

- return mlx90632_pwr_continuous(regmap);
+ data->mtyp = type;
+ data->powerstatus = MLX90632_PWR_STATUS_HALT;
+
+ if (current_powerstatus == MLX90632_PWR_STATUS_SLEEP_STEP)
+ return mlx90632_pwr_set_sleep_step(data->regmap);
+
+ return mlx90632_pwr_continuous(data->regmap);
}

static int mlx90632_channel_new_select(int perform_ret, uint8_t *channel_new,
@@ -355,11 +504,30 @@ static int mlx90632_read_all_channel(struct mlx90632_data *data,
s32 ret, measurement;

mutex_lock(&data->lock);
- measurement = mlx90632_perform_measurement(data);
- if (measurement < 0) {
- ret = measurement;
+ ret = mlx90632_set_meas_type(data, MLX90632_MTYP_MEDICAL);
+ if (ret < 0)
+ goto read_unlock;
+
+ switch (data->powerstatus) {
+ case MLX90632_PWR_STATUS_CONTINUOUS:
+ measurement = mlx90632_perform_measurement(data);
+ if (measurement < 0) {
+ ret = measurement;
+ goto read_unlock;
+ }
+ break;
+ case MLX90632_PWR_STATUS_SLEEP_STEP:
+ measurement = mlx90632_perform_measurement_burst(data);
+ if (measurement < 0) {
+ ret = measurement;
+ goto read_unlock;
+ }
+ break;
+ default:
+ ret = -ENOTSUPP;
goto read_unlock;
}
+
ret = mlx90632_read_ambient_raw(data->regmap, ambient_new_raw,
ambient_old_raw);
if (ret < 0)
@@ -441,14 +609,20 @@ static int mlx90632_read_all_channel_extended(struct mlx90632_data *data, s16 *o
s32 ret, meas;

mutex_lock(&data->lock);
- ret = mlx90632_set_meas_type(data->regmap, MLX90632_MTYP_EXTENDED);
+ ret = mlx90632_set_meas_type(data, MLX90632_MTYP_EXTENDED);
if (ret < 0)
goto read_unlock;

- ret = read_poll_timeout(mlx90632_perform_measurement, meas, meas == 19,
- 50000, 800000, false, data);
- if (ret != 0)
- goto read_unlock;
+ if (data->powerstatus == MLX90632_PWR_STATUS_CONTINUOUS) {
+ ret = read_poll_timeout(mlx90632_perform_measurement, meas, meas == 19,
+ 50000, 800000, false, data);
+ if (ret)
+ goto read_unlock;
+ } else if (data->powerstatus == MLX90632_PWR_STATUS_SLEEP_STEP) {
+ ret = mlx90632_perform_measurement_burst(data);
+ if (ret < 0)
+ goto read_unlock;
+ }

ret = mlx90632_read_object_raw_extended(data->regmap, object_new_raw);
if (ret < 0)
@@ -457,8 +631,6 @@ static int mlx90632_read_all_channel_extended(struct mlx90632_data *data, s16 *o
ret = mlx90632_read_ambient_raw_extended(data->regmap, ambient_new_raw, ambient_old_raw);

read_unlock:
- (void) mlx90632_set_meas_type(data->regmap, MLX90632_MTYP_MEDICAL);
-
mutex_unlock(&data->lock);
return ret;
}
@@ -743,12 +915,47 @@ static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
return ret;
}

+/**
+ * mlx90632_pm_interraction_wakeup() - Measure time between user interactions to change powermode
+ * @data: pointer to mlx90632_data object containing interaction_ts information
+ *
+ * Switch to continuous mode when interaction is faster than MLX90632_MEAS_MAX_TIME. Update the
+ * interaction_ts for each function call with the jiffies to enable measurement between function
+ * calls. Initial value of the interaction_ts needs to be set before this function call.
+ */
+static int mlx90632_pm_interraction_wakeup(struct mlx90632_data *data)
+{
+ unsigned long now;
+ int ret;
+
+ now = jiffies;
+ if (time_in_range(now, data->interaction_ts,
+ data->interaction_ts +
+ msecs_to_jiffies(MLX90632_MEAS_MAX_TIME + 100))) {
+ if (data->powerstatus == MLX90632_PWR_STATUS_SLEEP_STEP) {
+ ret = mlx90632_pwr_continuous(data->regmap);
+ if (ret < 0)
+ return ret;
+ }
+ }
+
+ data->interaction_ts = now;
+
+ return 0;
+}
+
static int mlx90632_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *channel, int *val,
int *val2, long mask)
{
struct mlx90632_data *data = iio_priv(indio_dev);
int ret;
+ int cr;
+
+ pm_runtime_get_sync(&data->client->dev);
+ ret = mlx90632_pm_interraction_wakeup(data);
+ if (ret < 0)
+ goto mlx90632_read_raw_pm;

switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
@@ -756,16 +963,22 @@ static int mlx90632_read_raw(struct iio_dev *indio_dev,
case IIO_MOD_TEMP_AMBIENT:
ret = mlx90632_calc_ambient_dsp105(data, val);
if (ret < 0)
- return ret;
- return IIO_VAL_INT;
+ goto mlx90632_read_raw_pm;
+
+ ret = IIO_VAL_INT;
+ break;
case IIO_MOD_TEMP_OBJECT:
ret = mlx90632_calc_object_dsp105(data, val);
if (ret < 0)
- return ret;
- return IIO_VAL_INT;
+ goto mlx90632_read_raw_pm;
+
+ ret = IIO_VAL_INT;
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ break;
}
+ break;
case IIO_CHAN_INFO_CALIBEMISSIVITY:
if (data->emissivity == 1000) {
*val = 1;
@@ -774,13 +987,21 @@ static int mlx90632_read_raw(struct iio_dev *indio_dev,
*val = 0;
*val2 = data->emissivity * 1000;
}
- return IIO_VAL_INT_PLUS_MICRO;
+ ret = IIO_VAL_INT_PLUS_MICRO;
+ break;
case IIO_CHAN_INFO_CALIBAMBIENT:
*val = data->object_ambient_temperature;
- return IIO_VAL_INT;
+ ret = IIO_VAL_INT;
+ break;
default:
- return -EINVAL;
+ ret = -EINVAL;
+ break;
}
+
+mlx90632_read_raw_pm:
+ pm_runtime_mark_last_busy(&data->client->dev);
+ pm_runtime_put_autosuspend(&data->client->dev);
+ return ret;
}

static int mlx90632_write_raw(struct iio_dev *indio_dev,
@@ -875,6 +1096,15 @@ static int mlx90632_enable_regulator(struct mlx90632_data *data)
return ret;
}

+static void mlx90632_pm_disable(void *data)
+{
+ struct device *dev = data;
+
+ pm_runtime_get_sync(dev);
+ pm_runtime_put_noidle(dev);
+ pm_runtime_disable(dev);
+}
+
static int mlx90632_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@@ -902,6 +1132,7 @@ static int mlx90632_probe(struct i2c_client *client,
mlx90632->client = client;
mlx90632->regmap = regmap;
mlx90632->mtyp = MLX90632_MTYP_MEDICAL;
+ mlx90632->powerstatus = MLX90632_PWR_STATUS_HALT;

mutex_init(&mlx90632->lock);
indio_dev->name = id->name;
@@ -961,16 +1192,25 @@ static int mlx90632_probe(struct i2c_client *client,

mlx90632->emissivity = 1000;
mlx90632->object_ambient_temperature = 25000; /* 25 degrees milliCelsius */
+ mlx90632->interaction_ts = jiffies; /* Set initial value */

- pm_runtime_disable(&client->dev);
+ pm_runtime_get_noresume(&client->dev);
ret = pm_runtime_set_active(&client->dev);
if (ret < 0) {
mlx90632_sleep(mlx90632);
return ret;
}
+
pm_runtime_enable(&client->dev);
pm_runtime_set_autosuspend_delay(&client->dev, MLX90632_SLEEP_DELAY_MS);
pm_runtime_use_autosuspend(&client->dev);
+ pm_runtime_put_autosuspend(&client->dev);
+
+ ret = devm_add_action_or_reset(&client->dev, mlx90632_pm_disable, &client->dev);
+ if (ret) {
+ mlx90632_sleep(mlx90632);
+ return ret;
+ }

return iio_device_register(indio_dev);
}
@@ -1003,30 +1243,47 @@ static const struct of_device_id mlx90632_of_match[] = {
};
MODULE_DEVICE_TABLE(of, mlx90632_of_match);

-static int __maybe_unused mlx90632_pm_suspend(struct device *dev)
+static int mlx90632_pm_suspend(struct device *dev)
{
- struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
- struct mlx90632_data *data = iio_priv(indio_dev);
+ struct mlx90632_data *data = iio_priv(dev_get_drvdata(dev));
+ int ret;
+
+ ret = mlx90632_pwr_set_sleep_step(data->regmap);
+ if (ret < 0)
+ return ret;

- return mlx90632_sleep(data);
+ ret = regulator_disable(data->regulator);
+ if (ret < 0)
+ dev_err(regmap_get_device(data->regmap),
+ "Failed to disable power regulator: %d\n", ret);
+
+ return ret;
}

-static int __maybe_unused mlx90632_pm_resume(struct device *dev)
+static int mlx90632_pm_resume(struct device *dev)
{
- struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
- struct mlx90632_data *data = iio_priv(indio_dev);
+ struct mlx90632_data *data = iio_priv(dev_get_drvdata(dev));

- return mlx90632_wakeup(data);
+ return mlx90632_enable_regulator(data);
}

-static UNIVERSAL_DEV_PM_OPS(mlx90632_pm_ops, mlx90632_pm_suspend,
- mlx90632_pm_resume, NULL);
+static int mlx90632_pm_runtime_suspend(struct device *dev)
+{
+ struct mlx90632_data *data = iio_priv(dev_get_drvdata(dev));
+
+ return mlx90632_pwr_set_sleep_step(data->regmap);
+}
+
+const struct dev_pm_ops mlx90632_pm_ops = {
+ SYSTEM_SLEEP_PM_OPS(mlx90632_pm_suspend, mlx90632_pm_resume)
+ RUNTIME_PM_OPS(mlx90632_pm_runtime_suspend, NULL, NULL)
+};

static struct i2c_driver mlx90632_driver = {
.driver = {
.name = "mlx90632",
.of_match_table = mlx90632_of_match,
- .pm = &mlx90632_pm_ops,
+ .pm = pm_ptr(&mlx90632_pm_ops),
},
.probe = mlx90632_probe,
.remove = mlx90632_remove,
--
2.34.1