iio: temperature: mlx90632: Add powermanagement

From: Crt Mori <[email protected]>

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 <[email protected]>

---
 drivers/iio/temperature/mlx90632.c | 347 +++++++++++++++++++++++++----
 1 file changed, 302 insertions(+), 45 deletions(-)

drivers/iio/temperature/mlx90632.c +302 -46

index 549c0ab5c2be..e41a18edbc65 100644
@@ -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

Very good and documented code, thanks!
I believe you better to use DEFINE_.*_PM_OPS instead of legacy ones (due to pm_ptr() usage).
Otherwise, with some nitpicks that wouldn't prevent a green light,

Reviewed-by Andy Shevchenko <[email protected]>

Quoted 7 lines · Andy Shevchenko

Very good and documented code, thanks!
I believe you better to use DEFINE_.*_PM_OPS instead of legacy ones (due to pm_ptr() usage).
Otherwise, with some nitpicks that wouldn't prevent a green light,

Reviewed-by Andy Shevchenko <[email protected]>

I checked DEFINE_.*_PM_OPS usage around drivers and you either have SIMPLE (where you define suspend/resume) or you have RUNTIME (for runtime suspend/resume), but never are those two together. So I am a bit puzzled how to get this working.

Quoted 8 lines · Crt Mori

Quoted 7 lines · Andy Shevchenko

Very good and documented code, thanks!
I believe you better to use DEFINE_.*_PM_OPS instead of legacy ones (due to pm_ptr() usage).
Otherwise, with some nitpicks that wouldn't prevent a green light,

Reviewed-by Andy Shevchenko <[email protected]>

Quoted 4 lines

I checked DEFINE_.*_PM_OPS usage around drivers and you either have SIMPLE (where you define suspend/resume) or you have RUNTIME (for runtime suspend/resume), but never are those two together. So I am a bit puzzled how to get this working.

The one which suits here is called _DEFINE_DEV_PM_OPS(). But it's basically the same what you put here with the possible unused case.

Quoted 14 lines · Andy Shevchenko

Quoted 12 lines · Crt Mori

Quoted 7 lines · Andy Shevchenko

Very good and documented code, thanks!
I believe you better to use DEFINE_.*_PM_OPS instead of legacy ones (due to pm_ptr() usage).
Otherwise, with some nitpicks that wouldn't prevent a green light,

Reviewed-by Andy Shevchenko <[email protected]>

I checked DEFINE_.*_PM_OPS usage around drivers and you either have SIMPLE (where you define suspend/resume) or you have RUNTIME (for runtime suspend/resume), but never are those two together. So I am a bit puzzled how to get this working.

Quoted 3 lines

The one which suits here is called _DEFINE_DEV_PM_OPS(). But it's basically the same what you put here with the possible unused case.

I thought underscore prefixed macros are the ones not to be used directly by drivers. I also found no occurrence in current drivers, so it was not something that was done so far?

Quoted 15 lines · Crt Mori

Quoted 14 lines · Andy Shevchenko

Quoted 12 lines · Crt Mori

Quoted 7 lines · Andy Shevchenko

Very good and documented code, thanks!
I believe you better to use DEFINE_.*_PM_OPS instead of legacy ones (due to pm_ptr() usage).
Otherwise, with some nitpicks that wouldn't prevent a green light,

Reviewed-by Andy Shevchenko <[email protected]>

I checked DEFINE_.*_PM_OPS usage around drivers and you either have SIMPLE (where you define suspend/resume) or you have RUNTIME (for runtime suspend/resume), but never are those two together. So I am a bit puzzled how to get this working.

Quoted 6 lines

Quoted 3 lines

The one which suits here is called _DEFINE_DEV_PM_OPS(). But it's basically the same what you put here with the possible unused case.

I thought underscore prefixed macros are the ones not to be used directly by drivers. I also found no occurrence in current drivers, so it was not something that was done so far?

Looks like... Okay, then let's leave it to the maintainer to decide.

From: Crt Mori <[email protected]>

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 <[email protected]>

drivers/iio/temperature/mlx90632.c +3 -0

+
+static int mlx90632_set_meas_type(struct mlx90632_data *data, u8 type)
+{
 
 
 
 static int mlx90632_write_raw(struct iio_dev *indio_dev,

drivers/iio/temperature/mlx90632.c +7 -1

+	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) {

drivers/iio/temperature/mlx90632.c +4 -0

+	if (ret) {
+		mlx90632_sleep(mlx90632);
+		return ret;
+	}
 
 	return iio_device_register(indio_dev);
 }

Quoted 1 line

+ pm_runtime_get_sync(dev);

So, this isn't quite enough.

Take a look at what devm_pm_runtime_enable()
does as the documentation for
pm_runtime_use_autosuspend()

I'd suggest using devm_pm_runtime_enable() and
an additional callback to turn the device on that
is registered after devm_pm_runtime_enable()
(so will maintain the ordering you have here).

Quoted 30 lines

drivers/iio/temperature/mlx90632.c +8 -1

+     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);

drivers/iio/temperature/mlx90632.c static int mlx90632_probe(struct i2c_client *client, · line 1209

Quoted 5 lines

drivers/iio/temperature/mlx90632.c +3 -0

      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);

Having moved those over to devm you need to also have dropped the calls in remove() (I only noticed this whilst trying to fix the autosuspend issue above.)

Quoted 7 lines

drivers/iio/temperature/mlx90632.c +4 -0

+     if (ret) {
+             mlx90632_sleep(mlx90632);
+             return ret;
+     }
 
      return iio_device_register(indio_dev);
 }

Quoted 7 lines

Quoted 1 line

+ pm_runtime_get_sync(dev);

So, this isn't quite enough.

Take a look at what devm_pm_runtime_enable()
does as the documentation for
pm_runtime_use_autosuspend()

Quoted 6 lines

I'd suggest using devm_pm_runtime_enable() and
an additional callback to turn the device on that
is registered after devm_pm_runtime_enable()
(so will maintain the ordering you have here).

Quoted 1 line

I copied this from pressure/bmp280-core driver. I had devm_pm originally, but was asked to replace it.

Quoted 31 lines

Quoted 31 lines

drivers/iio/temperature/mlx90632.c +8 -1

+     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);

Quoted 8 lines

drivers/iio/temperature/mlx90632.c static int mlx90632_probe(struct i2c_client *client, · line 1209

Quoted 5 lines

drivers/iio/temperature/mlx90632.c +3 -0

      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);  

Having moved those over to devm you need to also have dropped the calls in remove() (I only noticed this whilst trying to fix the autosuspend issue above.)

So in remove, there should be no pm calls, because mlx90632_pm_disable function handle all of it? I still keep the sleep call, so that it also puts the sensor in lowest state, or I rather keep it only in regulator_disable (which should also be called at removal)?

Quoted 9 lines

Quoted 8 lines

drivers/iio/temperature/mlx90632.c +4 -0

+     if (ret) {
+             mlx90632_sleep(mlx90632);
+             return ret;
+     }
 
      return iio_device_register(indio_dev);
 }  

From: Crt Mori <[email protected]>

Allow users to read sensor sampling frequency to better plan the application measurement requests.

Signed-off-by Crt Mori <[email protected]>

---
 drivers/iio/temperature/mlx90632.c | 51 ++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

drivers/iio/temperature/mlx90632.c +10 -0

index e41a18edbc65..6b33284eb0b6 100644
@@ -81,6 +81,9 @@
 #define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous */
 
 #define MLX90632_EE_RR GENMASK(10, 8) /* Only Refresh Rate bits */
+#define MLX90632_REFRESH_RATE(ee_val) FIELD_GET(MLX90632_EE_RR, ee_val)
+                                       /* Extract Refresh Rate from ee register */
+#define MLX90632_REFRESH_RATE_STATUS(refresh_rate) (refresh_rate << 8)
 
 /* Measurement types */
 #define MLX90632_MTYP_MEDICAL 0

@@ -915,6 +918,24 @@ static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
        return ret;
 }
 
+static int mlx90632_get_refresh_rate(struct mlx90632_data *data,
+                                    int *refresh_rate)
+{
+       unsigned int meas1;
+       int ret;
+
+       ret = regmap_read(data->regmap, MLX90632_EE_MEDICAL_MEAS1, &meas1);

drivers/iio/temperature/mlx90632.c +31 -1

+
 /**
  * mlx90632_pm_interraction_wakeup() - Measure time between user interactions to change powermode
  * @data: pointer to mlx90632_data object containing interaction_ts information

@@ -993,6 +1014,15 @@ static int mlx90632_read_raw(struct iio_dev *indio_dev,
                *val = data->object_ambient_temperature;
                ret = IIO_VAL_INT;
                break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               ret = mlx90632_get_refresh_rate(data, &cr);
+               if (ret < 0)
+                       goto mlx90632_read_raw_pm;
+
+               *val = mlx90632_freqs[cr][0];
+               *val2 = mlx90632_freqs[cr][1];
+               ret = IIO_VAL_INT_PLUS_MICRO;
+               break;
        default:
                ret = -EINVAL;
                break;

@@ -1026,12 +1056,30 @@ static int mlx90632_write_raw(struct iio_dev *indio_dev,
        }
 }
 
+static int mlx90632_read_avail(struct iio_dev *indio_dev,
+                              struct iio_chan_spec const *chan,
+                              const int **vals, int *type, int *length,
+                              long mask)
+{
+       switch (mask) {
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               *vals = (int *)mlx90632_freqs;
+               *type = IIO_VAL_INT_PLUS_MICRO;
+               *length = 2 * ARRAY_SIZE(mlx90632_freqs);
+               return IIO_AVAIL_LIST;
+       default:
+               return -EINVAL;
+       }
+}
+
 static const struct iio_chan_spec mlx90632_channels[] = {
        {
                .type = IIO_TEMP,
                .modified = 1,
                .channel2 = IIO_MOD_TEMP_AMBIENT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+               .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        },
        {
                .type = IIO_TEMP,

@@ -1039,12 +1087,15 @@ static const struct iio_chan_spec mlx90632_channels[] = {
                .channel2 = IIO_MOD_TEMP_OBJECT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
                        BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) | BIT(IIO_CHAN_INFO_CALIBAMBIENT),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+               .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        },
 };
 
 static const struct iio_info mlx90632_info = {
        .read_raw = mlx90632_read_raw,
        .write_raw = mlx90632_write_raw,
+       .read_avail = mlx90632_read_avail,
 };
 
 static int mlx90632_sleep(struct mlx90632_data *data)
--

2.34.1

Quoted 43 lines · On Tue, Sep 6, 2022 at 12:04 PM <[email protected]> wrote:

From: Crt Mori <[email protected]>

Allow users to read sensor sampling frequency to better plan the application measurement requests.

Signed-off-by Crt Mori <[email protected]>

---
 drivers/iio/temperature/mlx90632.c | 51 ++++++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

drivers/iio/temperature/mlx90632.c +17 -0

index e41a18edbc65..6b33284eb0b6 100644
@@ -81,6 +81,9 @@
 #define MLX90632_PWR_STATUS_CONTINUOUS MLX90632_PWR_STATUS(3) /* continuous */
 
 #define MLX90632_EE_RR GENMASK(10, 8) /* Only Refresh Rate bits */
+#define MLX90632_REFRESH_RATE(ee_val) FIELD_GET(MLX90632_EE_RR, ee_val)
+                                       /* Extract Refresh Rate from ee register */
+#define MLX90632_REFRESH_RATE_STATUS(refresh_rate) (refresh_rate << 8)
 
 /* Measurement types */
 #define MLX90632_MTYP_MEDICAL 0

@@ -915,6 +918,24 @@ static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val)
        return ret;
 }
 
+static int mlx90632_get_refresh_rate(struct mlx90632_data *data,
+                                    int *refresh_rate)
+{
+       unsigned int meas1;
+       int ret;
+
+       ret = regmap_read(data->regmap, MLX90632_EE_MEDICAL_MEAS1, &meas1);
+       if (ret < 0)
+               return ret;
+
+       *refresh_rate = MLX90632_REFRESH_RATE(meas1);
+
+       return ret;
+}

drivers/iio/temperature/mlx90632.c static int mlx90632_calc_ambient_dsp105(struct mlx90632_data *data, int *val) · line 937

Quoted 3 lines

drivers/iio/temperature/mlx90632.c +3 -0

+
+static const int mlx90632_freqs[][2] = { {0, 500000}, {1, 0}, {2, 0}, {4, 0},
+                                         {8, 0}, {16, 0}, {32, 0}, {64, 0} };  

I would indent this as
_freqs ... = {
...pairs...
};

Either way,

Reviewed-by Andy Shevchenko <[email protected]>

Quoted 70 lines

drivers/iio/temperature/mlx90632.c +31 -1

+
 /**
  * mlx90632_pm_interraction_wakeup() - Measure time between user interactions to change powermode
  * @data: pointer to mlx90632_data object containing interaction_ts information

@@ -993,6 +1014,15 @@ static int mlx90632_read_raw(struct iio_dev *indio_dev,
                *val = data->object_ambient_temperature;
                ret = IIO_VAL_INT;
                break;
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               ret = mlx90632_get_refresh_rate(data, &cr);
+               if (ret < 0)
+                       goto mlx90632_read_raw_pm;
+
+               *val = mlx90632_freqs[cr][0];
+               *val2 = mlx90632_freqs[cr][1];
+               ret = IIO_VAL_INT_PLUS_MICRO;
+               break;
        default:
                ret = -EINVAL;
                break;

@@ -1026,12 +1056,30 @@ static int mlx90632_write_raw(struct iio_dev *indio_dev,
        }
 }
 
+static int mlx90632_read_avail(struct iio_dev *indio_dev,
+                              struct iio_chan_spec const *chan,
+                              const int **vals, int *type, int *length,
+                              long mask)
+{
+       switch (mask) {
+       case IIO_CHAN_INFO_SAMP_FREQ:
+               *vals = (int *)mlx90632_freqs;
+               *type = IIO_VAL_INT_PLUS_MICRO;
+               *length = 2 * ARRAY_SIZE(mlx90632_freqs);
+               return IIO_AVAIL_LIST;
+       default:
+               return -EINVAL;
+       }
+}
+
 static const struct iio_chan_spec mlx90632_channels[] = {
        {
                .type = IIO_TEMP,
                .modified = 1,
                .channel2 = IIO_MOD_TEMP_AMBIENT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+               .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        },
        {
                .type = IIO_TEMP,

@@ -1039,12 +1087,15 @@ static const struct iio_chan_spec mlx90632_channels[] = {
                .channel2 = IIO_MOD_TEMP_OBJECT,
                .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
                        BIT(IIO_CHAN_INFO_CALIBEMISSIVITY) | BIT(IIO_CHAN_INFO_CALIBAMBIENT),
+               .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+               .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_SAMP_FREQ),
        },
 };
 
 static const struct iio_info mlx90632_info = {
        .read_raw = mlx90632_read_raw,
        .write_raw = mlx90632_write_raw,
+       .read_avail = mlx90632_read_avail,
 };
 
 static int mlx90632_sleep(struct mlx90632_data *data)
--

2.34.1

From: Crt Mori <[email protected]>

The current EINVAL value is more applicable to embedded library, where

user can actually put the fixed value to the sensor. In case of the driver if the value of the channel is invalid it is better in inform userspace that Channel was out of range as that implies more to internal driver error than invalid input. It also makes for easier debugging of where the error comes from during the development.

Signed-off-by Crt Mori <[email protected]>

---
 drivers/iio/temperature/mlx90632.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/iio/temperature/mlx90632.c +1 -2

index 6b33284eb0b6..aee065a38772 100644
@@ -436,7 +436,7 @@ static int mlx90632_channel_new_select(int perform_ret, uint8_t *channel_new,
                *channel_old = 1;
                break;
        default:
-               return -EINVAL;
+               return -ECHRNG;
        }
 
        return 0;
--

2.34.1