iio: imu: inv_icm42600: add support of accel low-power mode

Add ODRs accessible only in low-power mode. Switch automatically to
low-power or low-noise depending on the ODR set.

Add channel attributes "power_mode" and "power_mode_available" for
setting the power mode to use (low-noise or low-power) for ODRs
supporting both mode. Reading "power_mode" when the sensor is on
will return the actual mode and not the requested one. It will be
different when using ODRs not supported by the requested mode.

Use low-power mode by default.

Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Link: https://lore.kernel.org/r/20240605195949.766677-3-inv.git-commit@tdk.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600.h b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
index c4ac91f6bafea9eff513854923160d844b665fc1..3a07e43e4cf154f3107c015c30248330d8e677f8 100644 (file)
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600.h
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600.h
@@ -177,11 +177,15 @@ struct inv_icm42600_state {
  * struct inv_icm42600_sensor_state - sensor state variables
  * @scales:            table of scales.
  * @scales_len:                length (nb of items) of the scales table.
+ * @power_mode:                sensor requested power mode (for common frequencies)
+ * @filter:            sensor filter.
  * @ts:                        timestamp module states.
  */
 struct inv_icm42600_sensor_state {
        const int *scales;
        size_t scales_len;
+       enum inv_icm42600_sensor_mode power_mode;
+       enum inv_icm42600_filter filter;
        struct inv_sensors_timestamp ts;
 };
 

diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
index 83d8504ebfff43d8a11fc4d0636754e635361cbd..3927829dd344a18635abf392b37f0458dc2c3a3b 100644 (file)
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c
@@ -55,8 +55,108 @@ enum inv_icm42600_accel_scan {
        INV_ICM42600_ACCEL_SCAN_TIMESTAMP,
 };
 
+static const char * const inv_icm42600_accel_power_mode_items[] = {
+       "low-noise",
+       "low-power",
+};
+static const int inv_icm42600_accel_power_mode_values[] = {
+       INV_ICM42600_SENSOR_MODE_LOW_NOISE,
+       INV_ICM42600_SENSOR_MODE_LOW_POWER,
+};
+static const int inv_icm42600_accel_filter_values[] = {
+       INV_ICM42600_FILTER_BW_ODR_DIV_2,
+       INV_ICM42600_FILTER_AVG_16X,
+};
+
+static int inv_icm42600_accel_power_mode_set(struct iio_dev *indio_dev,
+                                            const struct iio_chan_spec *chan,
+                                            unsigned int idx)
+{
+       struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+       struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
+       int power_mode, filter;
+
+       if (chan->type != IIO_ACCEL)
+               return -EINVAL;
+
+       if (idx >= ARRAY_SIZE(inv_icm42600_accel_power_mode_values))
+               return -EINVAL;
+
+       if (iio_buffer_enabled(indio_dev))
+               return -EBUSY;
+
+       power_mode = inv_icm42600_accel_power_mode_values[idx];
+       filter = inv_icm42600_accel_filter_values[idx];
+
+       guard(mutex)(&st->lock);
+
+       /* prevent change if power mode is not supported by the ODR */
+       switch (power_mode) {
+       case INV_ICM42600_SENSOR_MODE_LOW_NOISE:
+               if (st->conf.accel.odr >= INV_ICM42600_ODR_6_25HZ_LP &&
+                   st->conf.accel.odr <= INV_ICM42600_ODR_1_5625HZ_LP)
+                       return -EPERM;
+               break;
+       case INV_ICM42600_SENSOR_MODE_LOW_POWER:
+       default:
+               if (st->conf.accel.odr <= INV_ICM42600_ODR_1KHZ_LN)
+                       return -EPERM;
+               break;
+       }
+
+       accel_st->power_mode = power_mode;
+       accel_st->filter = filter;
+
+       return 0;
+}
+
+static int inv_icm42600_accel_power_mode_get(struct iio_dev *indio_dev,
+                                            const struct iio_chan_spec *chan)
+{
+       struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+       struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
+       unsigned int idx;
+       int power_mode;
+
+       if (chan->type != IIO_ACCEL)
+               return -EINVAL;
+
+       guard(mutex)(&st->lock);
+
+       /* if sensor is on, returns actual power mode and not configured one */
+       switch (st->conf.accel.mode) {
+       case INV_ICM42600_SENSOR_MODE_LOW_POWER:
+       case INV_ICM42600_SENSOR_MODE_LOW_NOISE:
+               power_mode = st->conf.accel.mode;
+               break;
+       default:
+               power_mode = accel_st->power_mode;
+               break;
+       }
+
+       for (idx = 0; idx < ARRAY_SIZE(inv_icm42600_accel_power_mode_values); ++idx) {
+               if (power_mode == inv_icm42600_accel_power_mode_values[idx])
+                       break;
+       }
+       if (idx >= ARRAY_SIZE(inv_icm42600_accel_power_mode_values))
+               return -EINVAL;
+
+       return idx;
+}
+
+static const struct iio_enum inv_icm42600_accel_power_mode_enum = {
+       .items = inv_icm42600_accel_power_mode_items,
+       .num_items = ARRAY_SIZE(inv_icm42600_accel_power_mode_items),
+       .set = inv_icm42600_accel_power_mode_set,
+       .get = inv_icm42600_accel_power_mode_get,
+};
+
 static const struct iio_chan_spec_ext_info inv_icm42600_accel_ext_infos[] = {
        IIO_MOUNT_MATRIX(IIO_SHARED_BY_ALL, inv_icm42600_get_mount_matrix),
+       IIO_ENUM_AVAILABLE("power_mode", IIO_SHARED_BY_TYPE,
+                          &inv_icm42600_accel_power_mode_enum),
+       IIO_ENUM("power_mode", IIO_SHARED_BY_TYPE,
+                &inv_icm42600_accel_power_mode_enum),
        {},
 };
 
@@ -120,7 +220,8 @@ static int inv_icm42600_accel_update_scan_mode(struct iio_dev *indio_dev,
 
        if (*scan_mask & INV_ICM42600_SCAN_MASK_ACCEL_3AXIS) {
                /* enable accel sensor */
-               conf.mode = INV_ICM42600_SENSOR_MODE_LOW_NOISE;
+               conf.mode = accel_st->power_mode;
+               conf.filter = accel_st->filter;
                ret = inv_icm42600_set_accel_conf(st, &conf, &sleep_accel);
                if (ret)
                        goto out_unlock;
@@ -144,10 +245,12 @@ out_unlock:
        return ret;
 }
 
-static int inv_icm42600_accel_read_sensor(struct inv_icm42600_state *st,
+static int inv_icm42600_accel_read_sensor(struct iio_dev *indio_dev,
                                          struct iio_chan_spec const *chan,
                                          int16_t *val)
 {
+       struct inv_icm42600_state *st = iio_device_get_drvdata(indio_dev);
+       struct inv_icm42600_sensor_state *accel_st = iio_priv(indio_dev);
        struct device *dev = regmap_get_device(st->map);
        struct inv_icm42600_sensor_conf conf = INV_ICM42600_SENSOR_CONF_INIT;
        unsigned int reg;
@@ -175,7 +278,8 @@ static int inv_icm42600_accel_read_sensor(struct inv_icm42600_state *st,
        mutex_lock(&st->lock);
 
        /* enable accel sensor */
-       conf.mode = INV_ICM42600_SENSOR_MODE_LOW_NOISE;
+       conf.mode = accel_st->power_mode;
+       conf.filter = accel_st->filter;
        ret = inv_icm42600_set_accel_conf(st, &conf, NULL);
        if (ret)
                goto exit;
@@ -277,6 +381,12 @@ static int inv_icm42600_accel_write_scale(struct iio_dev *indio_dev,
 
 /* IIO format int + micro */
 static const int inv_icm42600_accel_odr[] = {
+       /* 1.5625Hz */
+       1, 562500,
+       /* 3.125Hz */
+       3, 125000,
+       /* 6.25Hz */
+       6, 250000,
        /* 12.5Hz */
        12, 500000,
        /* 25Hz */
@@ -296,6 +406,9 @@ static const int inv_icm42600_accel_odr[] = {
 };
 
 static const int inv_icm42600_accel_odr_conv[] = {
+       INV_ICM42600_ODR_1_5625HZ_LP,
+       INV_ICM42600_ODR_3_125HZ_LP,
+       INV_ICM42600_ODR_6_25HZ_LP,
        INV_ICM42600_ODR_12_5HZ,
        INV_ICM42600_ODR_25HZ,
        INV_ICM42600_ODR_50HZ,
@@ -581,7 +694,7 @@ static int inv_icm42600_accel_read_raw(struct iio_dev *indio_dev,
                ret = iio_device_claim_direct_mode(indio_dev);
                if (ret)
                        return ret;
-               ret = inv_icm42600_accel_read_sensor(st, chan, &data);
+               ret = inv_icm42600_accel_read_sensor(indio_dev, chan, &data);
                iio_device_release_direct_mode(indio_dev);
                if (ret)
                        return ret;
@@ -754,6 +867,9 @@ struct iio_dev *inv_icm42600_accel_init(struct inv_icm42600_state *st)
                accel_st->scales_len = ARRAY_SIZE(inv_icm42600_accel_scale);
                break;
        }
+       /* low-power by default at init */
+       accel_st->power_mode = INV_ICM42600_SENSOR_MODE_LOW_POWER;
+       accel_st->filter = INV_ICM42600_FILTER_AVG_16X;
 
        /*
         * clock period is 32kHz (31250ns)

diff --git a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
index ada5a8cca6294aec7a20f7892921b1b8de04d7e9..184ce942e5fb63e156a5ef6605c3b1bf86425a19 100644 (file)
--- a/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
+++ b/drivers/iio/imu/inv_icm42600/inv_icm42600_core.c
@@ -292,6 +292,23 @@ int inv_icm42600_set_accel_conf(struct inv_icm42600_state *st,
        if (conf->filter < 0)
                conf->filter = oldconf->filter;
 
+       /* force power mode against ODR when sensor is on */
+       switch (conf->mode) {
+       case INV_ICM42600_SENSOR_MODE_LOW_POWER:
+       case INV_ICM42600_SENSOR_MODE_LOW_NOISE:
+               if (conf->odr <= INV_ICM42600_ODR_1KHZ_LN) {
+                       conf->mode = INV_ICM42600_SENSOR_MODE_LOW_NOISE;
+                       conf->filter = INV_ICM42600_FILTER_BW_ODR_DIV_2;
+               } else if (conf->odr >= INV_ICM42600_ODR_6_25HZ_LP &&
+                          conf->odr <= INV_ICM42600_ODR_1_5625HZ_LP) {
+                       conf->mode = INV_ICM42600_SENSOR_MODE_LOW_POWER;
+                       conf->filter = INV_ICM42600_FILTER_AVG_16X;
+               }
+               break;
+       default:
+               break;
+       }
+
        /* set ACCEL_CONFIG0 register (accel fullscale & odr) */
        if (conf->fs != oldconf->fs || conf->odr != oldconf->odr) {
                val = INV_ICM42600_ACCEL_CONFIG0_FS(conf->fs) |
@@ -485,6 +502,16 @@ static int inv_icm42600_setup(struct inv_icm42600_state *st,
        if (ret)
                return ret;
 
+       /*
+        * Use RC clock for accel low-power to fix glitches when switching
+        * gyro on/off while accel low-power is on.
+        */
+       ret = regmap_update_bits(st->map, INV_ICM42600_REG_INTF_CONFIG1,
+                                INV_ICM42600_INTF_CONFIG1_ACCEL_LP_CLK_RC,
+                                INV_ICM42600_INTF_CONFIG1_ACCEL_LP_CLK_RC);
+       if (ret)
+               return ret;
+
        return inv_icm42600_set_conf(st, hw->conf);
 }