[PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Gustavo Silva]

Any-motion event can be enabled on a per-axis basis and triggers a
combined event when motion is detected on any axis.

No-motion event is triggered if the rate of change on all axes falls
below a specified threshold for a configurable duration. A fake channel
is used to report this event.

Threshold and duration can be configured from userspace.

Signed-off-by: Gustavo Silva <gustavograzs@gmail.com>
---
Changes in v4:
- Reworked the threshold for the any-motion event so that threshold *
  accel_scale is given in m/s^2, in accordance with the ABI
  Also the range of available values for the threshold is now determined
  dynamically based on the value of the accelerometer scale
- Fixed alignment and styling of some statements and macros
- Simplified the return statement in the bmi270_read_event_config()
  function by returning the boolean expression directly
---
 drivers/iio/imu/bmi270/bmi270_core.c | 384 +++++++++++++++++++++++++++++++++--
 1 file changed, 364 insertions(+), 20 deletions(-)

diff --git a/drivers/iio/imu/bmi270/bmi270_core.c b/drivers/iio/imu/bmi270/bmi270_core.c
index 519f1c9d466dceb301b53efee905f1b8fc4468c0..b9491618eb9b35632ea11de6f7052d8fdac394ba 100644
--- a/drivers/iio/imu/bmi270/bmi270_core.c
+++ b/drivers/iio/imu/bmi270/bmi270_core.c
@@ -31,6 +31,8 @@
 
 #define BMI270_INT_STATUS_0_REG				0x1c
 #define BMI270_INT_STATUS_0_STEP_CNT_MSK		BIT(1)
+#define BMI270_INT_STATUS_0_NOMOTION_MSK		BIT(5)
+#define BMI270_INT_STATUS_0_MOTION_MSK			BIT(6)
 
 #define BMI270_INT_STATUS_1_REG				0x1d
 #define BMI270_INT_STATUS_1_ACC_GYR_DRDY_MSK		GENMASK(7, 6)
@@ -81,6 +83,8 @@
 #define BMI270_INT1_MAP_FEAT_REG			0x56
 #define BMI270_INT2_MAP_FEAT_REG			0x57
 #define BMI270_INT_MAP_FEAT_STEP_CNT_WTRMRK_MSK		BIT(1)
+#define BMI270_INT_MAP_FEAT_NOMOTION_MSK		BIT(5)
+#define BMI270_INT_MAP_FEAT_ANYMOTION_MSK		BIT(6)
 
 #define BMI270_INT_MAP_DATA_REG				0x58
 #define BMI270_INT_MAP_DATA_DRDY_INT1_MSK		BIT(2)
@@ -106,6 +110,25 @@
 #define BMI270_STEP_SC26_RST_CNT_MSK			BIT(10)
 #define BMI270_STEP_SC26_EN_CNT_MSK			BIT(12)
 
+#define BMI270_FEAT_MOTION_DURATION_MSK			GENMASK(12, 0)
+#define BMI270_FEAT_MOTION_X_EN_MSK			BIT(13)
+#define BMI270_FEAT_MOTION_Y_EN_MSK			BIT(14)
+#define BMI270_FEAT_MOTION_Z_EN_MSK			BIT(15)
+#define BMI270_FEAT_MOTION_XYZ_EN_MSK			GENMASK(15, 13)
+#define BMI270_FEAT_MOTION_THRESHOLD_MSK		GENMASK(10, 0)
+#define BMI270_FEAT_MOTION_OUT_CONF_MSK			GENMASK(14, 11)
+#define BMI270_FEAT_MOTION_ENABLE_MSK			BIT(15)
+
+#define BMI270_MOTION_XYZ_MSK				GENMASK(2, 0)
+
+/* See pages 92 and 93 of the datasheet */
+#define BMI270_MOTION_THRES_FULL_SCALE			GENMASK(10, 0)
+#define BMI270_MOTION_DURAT_SCALE			50
+#define BMI270_MOTION_DURAT_MAX				162
+
+/* 9.81 * 1000000 m/s^2 */
+#define BMI270_G_MEGA_M_S_2				9810000
+
 /* See datasheet section 4.6.14, Temperature Sensor */
 #define BMI270_TEMP_OFFSET				11776
 #define BMI270_TEMP_SCALE				1953125
@@ -114,6 +137,11 @@
 #define BMI270_STEP_COUNTER_FACTOR			20
 #define BMI270_STEP_COUNTER_MAX				20460
 
+#define BMI270_INT_MICRO_TO_RAW(val, val2, scale) \
+	((val) * (scale) + ((val2) * (scale)) / MEGA)
+#define BMI270_RAW_TO_MICRO(raw, scale) \
+	((((raw) % (scale)) * MEGA) / scale)
+
 #define BMI260_INIT_DATA_FILE "bmi260-init-data.fw"
 #define BMI270_INIT_DATA_FILE "bmi270-init-data.fw"
 
@@ -309,6 +337,13 @@ static const struct  bmi270_odr_item bmi270_odr_table[] = {
 };
 
 enum bmi270_feature_reg_id {
+	/* Page 1 registers */
+	BMI270_ANYMO1_REG,
+	BMI270_ANYMO2_REG,
+	/* Page 2 registers */
+	BMI270_NOMO1_REG,
+	BMI270_NOMO2_REG,
+	/* Page 6 registers */
 	BMI270_SC_26_REG,
 };
 
@@ -318,6 +353,22 @@ struct bmi270_feature_reg {
 };
 
 static const struct bmi270_feature_reg bmi270_feature_regs[] = {
+	[BMI270_ANYMO1_REG] = {
+		.page = 1,
+		.addr = 0x3c,
+	},
+	[BMI270_ANYMO2_REG] = {
+		.page = 1,
+		.addr = 0x3e,
+	},
+	[BMI270_NOMO1_REG] = {
+		.page = 2,
+		.addr = 0x30,
+	},
+	[BMI270_NOMO2_REG] = {
+		.page = 2,
+		.addr = 0x32,
+	},
 	[BMI270_SC_26_REG] = {
 		.page = 6,
 		.addr = 0x32,
@@ -439,6 +490,121 @@ static int bmi270_step_wtrmrk_en(struct bmi270_data *data, bool state)
 					     state));
 }
 
+static int bmi270_motion_reg(enum iio_event_type type, enum iio_event_info info)
+{
+	switch (info) {
+	case IIO_EV_INFO_PERIOD:
+		switch (type) {
+		case IIO_EV_TYPE_MAG_ADAPTIVE:
+			return BMI270_ANYMO1_REG;
+		case IIO_EV_TYPE_ROC:
+			return BMI270_NOMO1_REG;
+		default:
+			return -EINVAL;
+		}
+	case IIO_EV_INFO_VALUE:
+		switch (type) {
+		case IIO_EV_TYPE_MAG_ADAPTIVE:
+			return BMI270_ANYMO2_REG;
+		case IIO_EV_TYPE_ROC:
+			return BMI270_NOMO2_REG;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int bmi270_anymotion_event_en(struct bmi270_data *data,
+				     struct iio_chan_spec const *chan,
+				     bool state)
+{
+	u16 axis_msk, axis_field_val, regval;
+	int ret, irq_reg;
+	bool axis_en;
+
+	irq_reg = bmi270_int_map_reg(data->irq_pin);
+	if (irq_reg < 0)
+		return irq_reg;
+
+	guard(mutex)(&data->mutex);
+
+	ret = bmi270_read_feature_reg(data, BMI270_ANYMO1_REG, &regval);
+	if (ret)
+		return ret;
+
+	switch (chan->channel2) {
+	case IIO_MOD_X:
+		axis_msk = BMI270_FEAT_MOTION_X_EN_MSK;
+		axis_field_val = FIELD_PREP(BMI270_FEAT_MOTION_X_EN_MSK, state);
+		axis_en = FIELD_GET(BMI270_FEAT_MOTION_Y_EN_MSK, regval) |
+			  FIELD_GET(BMI270_FEAT_MOTION_Z_EN_MSK, regval);
+		break;
+	case IIO_MOD_Y:
+		axis_msk = BMI270_FEAT_MOTION_Y_EN_MSK;
+		axis_field_val = FIELD_PREP(BMI270_FEAT_MOTION_Y_EN_MSK, state);
+		axis_en = FIELD_GET(BMI270_FEAT_MOTION_X_EN_MSK, regval) |
+			  FIELD_GET(BMI270_FEAT_MOTION_Z_EN_MSK, regval);
+		break;
+	case IIO_MOD_Z:
+		axis_msk = BMI270_FEAT_MOTION_Z_EN_MSK;
+		axis_field_val = FIELD_PREP(BMI270_FEAT_MOTION_Z_EN_MSK, state);
+		axis_en = FIELD_GET(BMI270_FEAT_MOTION_X_EN_MSK, regval) |
+			  FIELD_GET(BMI270_FEAT_MOTION_Y_EN_MSK, regval);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = bmi270_update_feature_reg(data, BMI270_ANYMO1_REG, axis_msk,
+					axis_field_val);
+	if (ret)
+		return ret;
+
+	ret = bmi270_update_feature_reg(data, BMI270_ANYMO2_REG,
+					BMI270_FEAT_MOTION_ENABLE_MSK,
+					FIELD_PREP(BMI270_FEAT_MOTION_ENABLE_MSK,
+						   state || axis_en));
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(data->regmap, irq_reg,
+				  BMI270_INT_MAP_FEAT_ANYMOTION_MSK,
+				  FIELD_PREP(BMI270_INT_MAP_FEAT_ANYMOTION_MSK,
+					     state || axis_en));
+}
+
+static int bmi270_nomotion_event_en(struct bmi270_data *data, bool state)
+{
+	int ret, irq_reg;
+
+	irq_reg = bmi270_int_map_reg(data->irq_pin);
+	if (irq_reg < 0)
+		return irq_reg;
+
+	guard(mutex)(&data->mutex);
+
+	ret = bmi270_update_feature_reg(data, BMI270_NOMO1_REG,
+					BMI270_FEAT_MOTION_XYZ_EN_MSK,
+					FIELD_PREP(BMI270_FEAT_MOTION_XYZ_EN_MSK,
+						   state ? BMI270_MOTION_XYZ_MSK : 0));
+	if (ret)
+		return ret;
+
+	ret = bmi270_update_feature_reg(data, BMI270_NOMO2_REG,
+					BMI270_FEAT_MOTION_ENABLE_MSK,
+					FIELD_PREP(BMI270_FEAT_MOTION_ENABLE_MSK,
+						   state));
+	if (ret)
+		return ret;
+
+	return regmap_update_bits(data->regmap, irq_reg,
+				  BMI270_INT_MAP_FEAT_NOMOTION_MSK,
+				  FIELD_PREP(BMI270_INT_MAP_FEAT_NOMOTION_MSK,
+					     state));
+}
+
 static int bmi270_set_scale(struct bmi270_data *data, int chan_type, int uscale)
 {
 	int i;
@@ -479,8 +645,6 @@ static int bmi270_get_scale(struct bmi270_data *data, int chan_type, int *scale,
 	unsigned int val;
 	struct bmi270_scale_item bmi270_scale_item;
 
-	guard(mutex)(&data->mutex);
-
 	switch (chan_type) {
 	case IIO_ACCEL:
 		ret = regmap_read(data->regmap, BMI270_ACC_CONF_RANGE_REG, &val);
@@ -614,6 +778,20 @@ static irqreturn_t bmi270_irq_thread_handler(int irq, void *private)
 	if (FIELD_GET(BMI270_INT_STATUS_1_ACC_GYR_DRDY_MSK, status1))
 		iio_trigger_poll_nested(data->trig);
 
+	if (FIELD_GET(BMI270_INT_STATUS_0_MOTION_MSK, status0))
+		iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
+							     IIO_MOD_X_OR_Y_OR_Z,
+							     IIO_EV_TYPE_MAG_ADAPTIVE,
+							     IIO_EV_DIR_RISING),
+			       timestamp);
+
+	if (FIELD_GET(BMI270_INT_STATUS_0_NOMOTION_MSK, status0))
+		iio_push_event(indio_dev, IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
+							     IIO_MOD_X_AND_Y_AND_Z,
+							     IIO_EV_TYPE_ROC,
+							     IIO_EV_DIR_RISING),
+			       timestamp);
+
 	if (FIELD_GET(BMI270_INT_STATUS_0_STEP_CNT_MSK, status0))
 		iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_STEPS, 0,
 							       IIO_EV_TYPE_CHANGE,
@@ -827,6 +1005,40 @@ static int bmi270_read_avail(struct iio_dev *indio_dev,
 	}
 }
 
+static ssize_t bmi270_show_accel_value_avail(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
+{
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct bmi270_data *data = iio_priv(indio_dev);
+	int ret, scale, uscale;
+	unsigned int step, max;
+
+	ret = bmi270_get_scale(data, IIO_ACCEL, &scale, &uscale);
+	if (ret)
+		return ret;
+
+	max = BMI270_G_MEGA_M_S_2 / uscale;
+	step = max / BMI270_MOTION_THRES_FULL_SCALE;
+
+	return sysfs_emit(buf, "[0 %u %u]\n", step, max);
+}
+
+static IIO_DEVICE_ATTR(in_accel_value_available, 0444,
+		       bmi270_show_accel_value_avail, NULL, 0);
+
+static IIO_CONST_ATTR(in_accel_period_available, "[0.0 0.02 162.0]");
+
+static struct attribute *bmi270_event_attributes[] = {
+	&iio_dev_attr_in_accel_value_available.dev_attr.attr,
+	&iio_const_attr_in_accel_period_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group bmi270_event_attribute_group = {
+	.attrs = bmi270_event_attributes,
+};
+
 static int bmi270_write_event_config(struct iio_dev *indio_dev,
 				     const struct iio_chan_spec *chan,
 				     enum iio_event_type type,
@@ -835,6 +1047,10 @@ static int bmi270_write_event_config(struct iio_dev *indio_dev,
 	struct bmi270_data *data = iio_priv(indio_dev);
 
 	switch (type) {
+	case IIO_EV_TYPE_MAG_ADAPTIVE:
+		return bmi270_anymotion_event_en(data, chan, state);
+	case IIO_EV_TYPE_ROC:
+		return bmi270_nomotion_event_en(data, state);
 	case IIO_EV_TYPE_CHANGE:
 		return bmi270_step_wtrmrk_en(data, state);
 	default:
@@ -848,21 +1064,57 @@ static int bmi270_read_event_config(struct iio_dev *indio_dev,
 				    enum iio_event_direction dir)
 {
 	struct bmi270_data *data = iio_priv(indio_dev);
+	bool feat_en, axis_en;
 	int ret, reg, regval;
+	u16 motion_reg;
 
 	guard(mutex)(&data->mutex);
 
+	reg = bmi270_int_map_reg(data->irq_pin);
+	if (reg < 0)
+		return reg;
+
+	ret = regmap_read(data->regmap, reg, &regval);
+	if (ret)
+		return ret;
+
 	switch (chan->type) {
 	case IIO_STEPS:
-		reg = bmi270_int_map_reg(data->irq_pin);
-		if (reg)
-			return reg;
+		return FIELD_GET(BMI270_INT_MAP_FEAT_STEP_CNT_WTRMRK_MSK, regval) ?
+									1 : 0;
+	case IIO_ACCEL:
+		switch (type) {
+		case IIO_EV_TYPE_ROC:
+			return FIELD_GET(BMI270_INT_MAP_FEAT_NOMOTION_MSK,
+					 regval) ? 1 : 0;
+		case IIO_EV_TYPE_MAG_ADAPTIVE:
+			ret = bmi270_read_feature_reg(data, BMI270_ANYMO1_REG,
+						      &motion_reg);
+			if (ret)
+				return ret;
 
-		ret = regmap_read(data->regmap, reg, &regval);
-		if (ret)
-			return ret;
-		return FIELD_GET(BMI270_INT_MAP_FEAT_STEP_CNT_WTRMRK_MSK,
-				 regval) ? 1 : 0;
+			feat_en = FIELD_GET(BMI270_INT_MAP_FEAT_ANYMOTION_MSK,
+					    regval);
+			switch (chan->channel2) {
+			case IIO_MOD_X:
+				axis_en = FIELD_GET(BMI270_FEAT_MOTION_X_EN_MSK,
+						    motion_reg);
+				break;
+			case IIO_MOD_Y:
+				axis_en = FIELD_GET(BMI270_FEAT_MOTION_Y_EN_MSK,
+						    motion_reg);
+				break;
+			case IIO_MOD_Z:
+				axis_en = FIELD_GET(BMI270_FEAT_MOTION_Z_EN_MSK,
+						    motion_reg);
+				break;
+			default:
+				return -EINVAL;
+			}
+			return axis_en && feat_en;
+		default:
+			return -EINVAL;
+		}
 	default:
 		return -EINVAL;
 	}
@@ -876,20 +1128,50 @@ static int bmi270_write_event_value(struct iio_dev *indio_dev,
 				    int val, int val2)
 {
 	struct bmi270_data *data = iio_priv(indio_dev);
-	unsigned int raw;
+	unsigned int raw, mask, regval;
+	int ret, reg, scale, uscale;
+	u64 tmp;
 
 	guard(mutex)(&data->mutex);
 
-	switch (type) {
-	case IIO_EV_TYPE_CHANGE:
+	if (type == IIO_EV_TYPE_CHANGE) {
 		if (!in_range(val, 0, BMI270_STEP_COUNTER_MAX + 1))
 			return -EINVAL;
 
 		raw = val / BMI270_STEP_COUNTER_FACTOR;
-		return bmi270_update_feature_reg(data, BMI270_SC_26_REG,
-						 BMI270_STEP_SC26_WTRMRK_MSK,
-						 FIELD_PREP(BMI270_STEP_SC26_WTRMRK_MSK,
-							    raw));
+		mask = BMI270_STEP_SC26_WTRMRK_MSK;
+		regval = FIELD_PREP(BMI270_STEP_SC26_WTRMRK_MSK, raw);
+		return bmi270_update_feature_reg(data, BMI270_SC_26_REG, mask,
+						 regval);
+	}
+
+	reg = bmi270_motion_reg(type, info);
+	if (reg < 0)
+		return reg;
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		ret = bmi270_get_scale(data, IIO_ACCEL, &scale, &uscale);
+		if (ret)
+			return ret;
+
+		if (!in_range(val, 0, (BMI270_G_MEGA_M_S_2 / uscale) + 1))
+			return -EINVAL;
+
+		tmp = (u64)val * BMI270_MOTION_THRES_FULL_SCALE * uscale;
+		raw = DIV_ROUND_CLOSEST_ULL(tmp, BMI270_G_MEGA_M_S_2);
+		mask = BMI270_FEAT_MOTION_THRESHOLD_MSK;
+		regval = FIELD_PREP(BMI270_FEAT_MOTION_THRESHOLD_MSK, raw);
+		return bmi270_update_feature_reg(data, reg, mask, regval);
+	case IIO_EV_INFO_PERIOD:
+		if (!in_range(val, 0, BMI270_MOTION_DURAT_MAX + 1))
+			return -EINVAL;
+
+		raw = BMI270_INT_MICRO_TO_RAW(val, val2,
+					      BMI270_MOTION_DURAT_SCALE);
+		mask = BMI270_FEAT_MOTION_DURATION_MSK;
+		regval = FIELD_PREP(BMI270_FEAT_MOTION_DURATION_MSK, raw);
+		return bmi270_update_feature_reg(data, reg, mask, regval);
 	default:
 		return -EINVAL;
 	}
@@ -903,14 +1185,14 @@ static int bmi270_read_event_value(struct iio_dev *indio_dev,
 				   int *val, int *val2)
 {
 	struct bmi270_data *data = iio_priv(indio_dev);
+	int ret, reg, scale, uscale;
 	unsigned int raw;
 	u16 regval;
-	int ret;
+	u64 tmp;
 
 	guard(mutex)(&data->mutex);
 
-	switch (type) {
-	case IIO_EV_TYPE_CHANGE:
+	if (type == IIO_EV_TYPE_CHANGE) {
 		ret = bmi270_read_feature_reg(data, BMI270_SC_26_REG, &regval);
 		if (ret)
 			return ret;
@@ -918,6 +1200,36 @@ static int bmi270_read_event_value(struct iio_dev *indio_dev,
 		raw = FIELD_GET(BMI270_STEP_SC26_WTRMRK_MSK, regval);
 		*val = raw * BMI270_STEP_COUNTER_FACTOR;
 		return IIO_VAL_INT;
+	}
+
+	reg = bmi270_motion_reg(type, info);
+	if (reg < 0)
+		return reg;
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		ret = bmi270_read_feature_reg(data, reg, &regval);
+		if (ret)
+			return ret;
+
+		ret = bmi270_get_scale(data, IIO_ACCEL, &scale, &uscale);
+		if (ret)
+			return ret;
+
+		raw = FIELD_GET(BMI270_FEAT_MOTION_THRESHOLD_MSK, regval);
+		tmp = (u64)raw * BMI270_G_MEGA_M_S_2;
+		*val = DIV_ROUND_CLOSEST_ULL(tmp,
+					     BMI270_MOTION_THRES_FULL_SCALE * uscale);
+		return IIO_VAL_INT;
+	case IIO_EV_INFO_PERIOD:
+		ret = bmi270_read_feature_reg(data, reg, &regval);
+		if (ret)
+			return ret;
+
+		raw = FIELD_GET(BMI270_FEAT_MOTION_DURATION_MSK, regval);
+		*val = raw / BMI270_MOTION_DURAT_SCALE;
+		*val2 = BMI270_RAW_TO_MICRO(raw, BMI270_MOTION_DURAT_SCALE);
+		return IIO_VAL_INT_PLUS_MICRO;
 	default:
 		return -EINVAL;
 	}
@@ -929,6 +1241,20 @@ static const struct iio_event_spec bmi270_step_wtrmrk_event = {
 	.mask_shared_by_type = BIT(IIO_EV_INFO_ENABLE) | BIT(IIO_EV_INFO_VALUE),
 };
 
+static const struct iio_event_spec bmi270_anymotion_event = {
+	.type = IIO_EV_TYPE_MAG_ADAPTIVE,
+	.dir = IIO_EV_DIR_RISING,
+	.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_PERIOD),
+};
+
+static const struct iio_event_spec bmi270_nomotion_event = {
+	.type = IIO_EV_TYPE_ROC,
+	.dir = IIO_EV_DIR_RISING,
+	.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	.mask_shared_by_type = BIT(IIO_EV_INFO_VALUE) | BIT(IIO_EV_INFO_PERIOD),
+};
+
 static const struct iio_info bmi270_info = {
 	.read_raw = bmi270_read_raw,
 	.write_raw = bmi270_write_raw,
@@ -937,6 +1263,7 @@ static const struct iio_info bmi270_info = {
 	.read_event_config = bmi270_read_event_config,
 	.write_event_value = bmi270_write_event_value,
 	.read_event_value = bmi270_read_event_value,
+	.event_attrs = &bmi270_event_attribute_group,
 };
 
 #define BMI270_ACCEL_CHANNEL(_axis) {				\
@@ -956,6 +1283,8 @@ static const struct iio_info bmi270_info = {
 		.storagebits = 16,				\
 		.endianness = IIO_LE,				\
 	},	                                                \
+	.event_spec = &bmi270_anymotion_event,			\
+	.num_event_specs = 1,					\
 }
 
 #define BMI270_ANG_VEL_CHANNEL(_axis) {				\
@@ -1000,6 +1329,14 @@ static const struct iio_chan_spec bmi270_channels[] = {
 		.num_event_specs = 1,
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(BMI270_SCAN_TIMESTAMP),
+	{
+		.type = IIO_ACCEL,
+		.modified = 1,
+		.channel2 = IIO_MOD_X_AND_Y_AND_Z,
+		.scan_index = -1, /* Fake channel */
+		.event_spec = &bmi270_nomotion_event,
+		.num_event_specs = 1,
+	},
 };
 
 static int bmi270_int_pin_config(struct bmi270_data *data,
@@ -1107,6 +1444,13 @@ static int bmi270_trigger_probe(struct bmi270_data *data,
 		return dev_err_probe(data->dev, ret,
 				     "Trigger registration failed\n");
 
+	/* Disable axes for motion events */
+	ret = bmi270_update_feature_reg(data, BMI270_ANYMO1_REG,
+					BMI270_FEAT_MOTION_XYZ_EN_MSK,
+					FIELD_PREP(BMI270_FEAT_MOTION_XYZ_EN_MSK, 0));
+	if (ret)
+		return ret;
+
 	data->irq_pin = irq_pin;
 
 	return 0;

-- 
2.50.0

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Andy Shevchenko]

On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:
> Any-motion event can be enabled on a per-axis basis and triggers a
> combined event when motion is detected on any axis.
> 
> No-motion event is triggered if the rate of change on all axes falls
> below a specified threshold for a configurable duration. A fake channel
> is used to report this event.
> 
> Threshold and duration can be configured from userspace.

...

> +/* 9.81 * 1000000 m/s^2 */
> +#define BMI270_G_MEGA_M_S_2				9810000

I thought this is MICRO...

...

> +#define BMI270_INT_MICRO_TO_RAW(val, val2, scale) \
> +	((val) * (scale) + ((val2) * (scale)) / MEGA)

Side note: Perhaps good candidate to have it in math.h
(AFAIR there are more users of the same.)

> +#define BMI270_RAW_TO_MICRO(raw, scale) \
> +	((((raw) % (scale)) * MEGA) / scale)

...

> +static ssize_t bmi270_show_accel_value_avail(struct device *dev,
> +					     struct device_attribute *attr,
> +					     char *buf)
> +{
> +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> +	struct bmi270_data *data = iio_priv(indio_dev);
> +	int ret, scale, uscale;
> +	unsigned int step, max;
> +
> +	ret = bmi270_get_scale(data, IIO_ACCEL, &scale, &uscale);
> +	if (ret)
> +		return ret;
> +
> +	max = BMI270_G_MEGA_M_S_2 / uscale;

...as here we divide 10^6/10^-6 semantically speaking.

> +	step = max / BMI270_MOTION_THRES_FULL_SCALE;
> +
> +	return sysfs_emit(buf, "[0 %u %u]\n", step, max);
> +}

Is this already documented in ABI?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Andy Shevchenko]

On Tue, Jul 15, 2025 at 10:37:22AM +0300, Andy Shevchenko wrote:
> On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:

...

> > +/* 9.81 * 1000000 m/s^2 */
> > +#define BMI270_G_MEGA_M_S_2				9810000
> 
> I thought this is MICRO...

Btw, what if we use the device on poles and on equator (or even on orbital
station)? I'm wondering if this constant should be defined in units.h or
even in uAPI that user space may add a correction if needed.


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Gustavo Silva]

On Tue, Jul 15, 2025 at 10:49:25AM +0300, Andy Shevchenko wrote:
> On Tue, Jul 15, 2025 at 10:37:22AM +0300, Andy Shevchenko wrote:
> > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:
> 
> ...
> 
> > > +/* 9.81 * 1000000 m/s^2 */
> > > +#define BMI270_G_MEGA_M_S_2				9810000
> > 
> > I thought this is MICRO...
> 
> Btw, what if we use the device on poles and on equator (or even on orbital
> station)? I'm wondering if this constant should be defined in units.h or
> even in uAPI that user space may add a correction if needed.
> 
I certainly hadn't thought about these scenarios.
FWIW, the accelerometer scale values also assume g = 9.81 m/s^2.
For example, 0.000598 = 2 * 9.81 / 32768

> 
> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Andy Shevchenko]

On Tue, Jul 15, 2025 at 08:55:35PM -0300, Gustavo Silva wrote:
> On Tue, Jul 15, 2025 at 10:49:25AM +0300, Andy Shevchenko wrote:
> > On Tue, Jul 15, 2025 at 10:37:22AM +0300, Andy Shevchenko wrote:
> > > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:

...

> > > > +/* 9.81 * 1000000 m/s^2 */
> > > > +#define BMI270_G_MEGA_M_S_2				9810000
> > > 
> > > I thought this is MICRO...
> > 
> > Btw, what if we use the device on poles and on equator (or even on orbital
> > station)? I'm wondering if this constant should be defined in units.h or
> > even in uAPI that user space may add a correction if needed.
> > 
> I certainly hadn't thought about these scenarios.
> FWIW, the accelerometer scale values also assume g = 9.81 m/s^2.
> For example, 0.000598 = 2 * 9.81 / 32768

Right, but this should be supplied to user space somehow. OTOH the measure error
may be high enough (what is the precision of the measurements by the way?) that
it will neglect the differences in the 'g' constant.

All the details are given in [1].

[1]: https://en.wikipedia.org/wiki/Gravity_of_Earth#:~:text=The%20precise%20strength%20of%20Earth's,/s2)%20by%20definition.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Jonathan Cameron]

On Wed, 16 Jul 2025 12:53:55 +0300
Andy Shevchenko <andriy.shevchenko@intel.com> wrote:

> On Tue, Jul 15, 2025 at 08:55:35PM -0300, Gustavo Silva wrote:
> > On Tue, Jul 15, 2025 at 10:49:25AM +0300, Andy Shevchenko wrote:  
> > > On Tue, Jul 15, 2025 at 10:37:22AM +0300, Andy Shevchenko wrote:  
> > > > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:  
> 
> ...
> 
> > > > > +/* 9.81 * 1000000 m/s^2 */
> > > > > +#define BMI270_G_MEGA_M_S_2				9810000  
> > > > 
> > > > I thought this is MICRO...  
> > > 
> > > Btw, what if we use the device on poles and on equator (or even on orbital
> > > station)? I'm wondering if this constant should be defined in units.h or
> > > even in uAPI that user space may add a correction if needed.
> > >   
> > I certainly hadn't thought about these scenarios.
> > FWIW, the accelerometer scale values also assume g = 9.81 m/s^2.
> > For example, 0.000598 = 2 * 9.81 / 32768  
> 
> Right, but this should be supplied to user space somehow. OTOH the measure error
> may be high enough (what is the precision of the measurements by the way?) that
> it will neglect the differences in the 'g' constant.
> 
> All the details are given in [1].
> 
> [1]: https://en.wikipedia.org/wiki/Gravity_of_Earth#:~:text=The%20precise%20strength%20of%20Earth's,/s2)%20by%20definition.
> 

These sensors don't measure relative to g.
That's annoying marketing which is why I held firm for m/s^2 for IIO :)
So what they measure for a given acceleration does not change depending
on where we are on earth. You should use a 'fixed' standard value for
conversion from marketing values in g to m/s^2..

Or maybe I'm missing something!

Jonathan
  

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Andy Shevchenko]

On Thu, Jul 24, 2025 at 04:22:27PM +0100, Jonathan Cameron wrote:
> On Wed, 16 Jul 2025 12:53:55 +0300
> Andy Shevchenko <andriy.shevchenko@intel.com> wrote:
> > On Tue, Jul 15, 2025 at 08:55:35PM -0300, Gustavo Silva wrote:
> > > On Tue, Jul 15, 2025 at 10:49:25AM +0300, Andy Shevchenko wrote:  
> > > > On Tue, Jul 15, 2025 at 10:37:22AM +0300, Andy Shevchenko wrote:  
> > > > > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:  

...

> > > > > > +/* 9.81 * 1000000 m/s^2 */
> > > > > > +#define BMI270_G_MEGA_M_S_2				9810000  
> > > > > 
> > > > > I thought this is MICRO...  
> > > > 
> > > > Btw, what if we use the device on poles and on equator (or even on orbital
> > > > station)? I'm wondering if this constant should be defined in units.h or
> > > > even in uAPI that user space may add a correction if needed.
> > > >   
> > > I certainly hadn't thought about these scenarios.
> > > FWIW, the accelerometer scale values also assume g = 9.81 m/s^2.
> > > For example, 0.000598 = 2 * 9.81 / 32768  
> > 
> > Right, but this should be supplied to user space somehow. OTOH the measure error
> > may be high enough (what is the precision of the measurements by the way?) that
> > it will neglect the differences in the 'g' constant.
> > 
> > All the details are given in [1].
> > 
> > [1]: https://en.wikipedia.org/wiki/Gravity_of_Earth#:~:text=The%20precise%20strength%20of%20Earth's,/s2)%20by%20definition.
> 
> These sensors don't measure relative to g.

What do they measure? Any links for me to study?

> That's annoying marketing which is why I held firm for m/s^2 for IIO :)
> So what they measure for a given acceleration does not change depending
> on where we are on earth. You should use a 'fixed' standard value for
> conversion from marketing values in g to m/s^2..

Hmm... But shouldn't that marketing value be exposed to user space?


-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Jonathan Cameron]

On Fri, 25 Jul 2025 00:26:35 +0300
Andy Shevchenko <andriy.shevchenko@intel.com> wrote:

> On Thu, Jul 24, 2025 at 04:22:27PM +0100, Jonathan Cameron wrote:
> > On Wed, 16 Jul 2025 12:53:55 +0300
> > Andy Shevchenko <andriy.shevchenko@intel.com> wrote:  
> > > On Tue, Jul 15, 2025 at 08:55:35PM -0300, Gustavo Silva wrote:  
> > > > On Tue, Jul 15, 2025 at 10:49:25AM +0300, Andy Shevchenko wrote:    
> > > > > On Tue, Jul 15, 2025 at 10:37:22AM +0300, Andy Shevchenko wrote:    
> > > > > > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:    
> 
> ...
> 
> > > > > > > +/* 9.81 * 1000000 m/s^2 */
> > > > > > > +#define BMI270_G_MEGA_M_S_2				9810000    
> > > > > > 
> > > > > > I thought this is MICRO...    
> > > > > 
> > > > > Btw, what if we use the device on poles and on equator (or even on orbital
> > > > > station)? I'm wondering if this constant should be defined in units.h or
> > > > > even in uAPI that user space may add a correction if needed.
> > > > >     
> > > > I certainly hadn't thought about these scenarios.
> > > > FWIW, the accelerometer scale values also assume g = 9.81 m/s^2.
> > > > For example, 0.000598 = 2 * 9.81 / 32768    
> > > 
> > > Right, but this should be supplied to user space somehow. OTOH the measure error
> > > may be high enough (what is the precision of the measurements by the way?) that
> > > it will neglect the differences in the 'g' constant.
> > > 
> > > All the details are given in [1].
> > > 
> > > [1]: https://en.wikipedia.org/wiki/Gravity_of_Earth#:~:text=The%20precise%20strength%20of%20Earth's,/s2)%20by%20definition.  
> > 
> > These sensors don't measure relative to g.  
> 
> What do they measure? Any links for me to study?
m/s^2 (well actually not, but they derive that from change in properties of a capacitor like structure as it bends under
the force generated by the acceleration.  Which in the vertical direction is g if the device isn't moving.

https://www.analog.com/en/resources/technical-articles/accelerometer-and-gyroscopes-sensors-operation-sensing-and-applications.html
looks good as an intro from a very quick glance.

> 
> > That's annoying marketing which is why I held firm for m/s^2 for IIO :)
> > So what they measure for a given acceleration does not change depending
> > on where we are on earth. You should use a 'fixed' standard value for
> > conversion from marketing values in g to m/s^2..  
> 
> Hmm... But shouldn't that marketing value be exposed to user space?

yes, but its 9.81 where ever you are. Or whatever the datasheet says they use.
These things are rarely that well calibrated, so the exact value gets lost in the
errors!

Jonathan



> 
> 

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Jonathan Cameron]

On Sun, 27 Jul 2025 16:49:09 +0100
Jonathan Cameron <jic23@kernel.org> wrote:

> On Fri, 25 Jul 2025 00:26:35 +0300
> Andy Shevchenko <andriy.shevchenko@intel.com> wrote:
> 
> > On Thu, Jul 24, 2025 at 04:22:27PM +0100, Jonathan Cameron wrote:  
> > > On Wed, 16 Jul 2025 12:53:55 +0300
> > > Andy Shevchenko <andriy.shevchenko@intel.com> wrote:    
> > > > On Tue, Jul 15, 2025 at 08:55:35PM -0300, Gustavo Silva wrote:    
> > > > > On Tue, Jul 15, 2025 at 10:49:25AM +0300, Andy Shevchenko wrote:      
> > > > > > On Tue, Jul 15, 2025 at 10:37:22AM +0300, Andy Shevchenko wrote:      
> > > > > > > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:      
> > 
> > ...
> >   
> > > > > > > > +/* 9.81 * 1000000 m/s^2 */
> > > > > > > > +#define BMI270_G_MEGA_M_S_2				9810000      
> > > > > > > 
> > > > > > > I thought this is MICRO...      
> > > > > > 
> > > > > > Btw, what if we use the device on poles and on equator (or even on orbital
> > > > > > station)? I'm wondering if this constant should be defined in units.h or
> > > > > > even in uAPI that user space may add a correction if needed.
> > > > > >       
> > > > > I certainly hadn't thought about these scenarios.
> > > > > FWIW, the accelerometer scale values also assume g = 9.81 m/s^2.
> > > > > For example, 0.000598 = 2 * 9.81 / 32768      
> > > > 
> > > > Right, but this should be supplied to user space somehow. OTOH the measure error
> > > > may be high enough (what is the precision of the measurements by the way?) that
> > > > it will neglect the differences in the 'g' constant.
> > > > 
> > > > All the details are given in [1].
> > > > 
> > > > [1]: https://en.wikipedia.org/wiki/Gravity_of_Earth#:~:text=The%20precise%20strength%20of%20Earth's,/s2)%20by%20definition.    
> > > 
> > > These sensors don't measure relative to g.    
> > 
> > What do they measure? Any links for me to study?  
> m/s^2 (well actually not, but they derive that from change in properties of a capacitor like structure as it bends under
> the force generated by the acceleration.  Which in the vertical direction is g if the device isn't moving.
> 
> https://www.analog.com/en/resources/technical-articles/accelerometer-and-gyroscopes-sensors-operation-sensing-and-applications.html
> looks good as an intro from a very quick glance.
> 
> >   
> > > That's annoying marketing which is why I held firm for m/s^2 for IIO :)
> > > So what they measure for a given acceleration does not change depending
> > > on where we are on earth. You should use a 'fixed' standard value for
> > > conversion from marketing values in g to m/s^2..    
> > 
> > Hmm... But shouldn't that marketing value be exposed to user space?  
> 
> yes, but its 9.81 where ever you are. Or whatever the datasheet says they use.
> These things are rarely that well calibrated, so the exact value gets lost in the
> errors!
> 
> Jonathan
> 
I got lost in this thread, so perhaps am assuming there is a v5 to come.

Maybe just send one anyway even if no changes as it'll jump up my list to look at.

Jonathan

> 
> 
> > 
> >   
> 
> 

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Gustavo Silva]

On Sat, Aug 02, 2025 at 12:58:21PM +0100, Jonathan Cameron wrote:
> > 
> I got lost in this thread, so perhaps am assuming there is a v5 to come.
> 
> Maybe just send one anyway even if no changes as it'll jump up my list to look at.
> 
> Jonathan
> 

Hi Jonathan,

Yes, I’ve yet to send v5. Just a quick reminder: patches 1 and 2 from
this series were already accepted as of v3.

Regarding v5, would it make sense to split it into two separate patches:
one for the motion events and another for the ABI documentation?

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Jonathan Cameron]

On Mon, 4 Aug 2025 19:26:03 -0300
Gustavo Silva <gustavograzs@gmail.com> wrote:

> On Sat, Aug 02, 2025 at 12:58:21PM +0100, Jonathan Cameron wrote:
> > >   
> > I got lost in this thread, so perhaps am assuming there is a v5 to come.
> > 
> > Maybe just send one anyway even if no changes as it'll jump up my list to look at.
> > 
> > Jonathan
> >   
> 
> Hi Jonathan,
> 
> Yes, I’ve yet to send v5. Just a quick reminder: patches 1 and 2 from
> this series were already accepted as of v3.
> 
> Regarding v5, would it make sense to split it into two separate patches:
> one for the motion events and another for the ABI documentation?

I'm a bit lost (and short on time, after a garage door crisis - always
have spare cables and helpful friends - both of which I did :)

Anyhow, if ABI is custom in same patch as the code that implements it.
If documenting new or existing (docs missing) then separate patch.

Jonathan

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Gustavo Silva]

On Tue, Jul 15, 2025 at 10:37:21AM +0300, Andy Shevchenko wrote:
> On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:
> > Any-motion event can be enabled on a per-axis basis and triggers a
> > combined event when motion is detected on any axis.
> > 
> > No-motion event is triggered if the rate of change on all axes falls
> > below a specified threshold for a configurable duration. A fake channel
> > is used to report this event.
> > 
> > Threshold and duration can be configured from userspace.
> 
Hi Andy. Thanks for the review.

> ...
> 
> > +/* 9.81 * 1000000 m/s^2 */
> > +#define BMI270_G_MEGA_M_S_2				9810000
> 
> I thought this is MICRO...
> 
> ...
> 
> > +#define BMI270_INT_MICRO_TO_RAW(val, val2, scale) \
> > +	((val) * (scale) + ((val2) * (scale)) / MEGA)
> 
> Side note: Perhaps good candidate to have it in math.h
> (AFAIR there are more users of the same.)
> 
Sure. I can submit a follow-up patch for that.

> > +#define BMI270_RAW_TO_MICRO(raw, scale) \
> > +	((((raw) % (scale)) * MEGA) / scale)
> 
> > +static ssize_t bmi270_show_accel_value_avail(struct device *dev,
> > +					     struct device_attribute *attr,
> > +					     char *buf)
> > +{
> > +	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
> > +	struct bmi270_data *data = iio_priv(indio_dev);
> > +	int ret, scale, uscale;
> > +	unsigned int step, max;
> > +
> > +	ret = bmi270_get_scale(data, IIO_ACCEL, &scale, &uscale);
> > +	if (ret)
> > +		return ret;
> > +
> > +	max = BMI270_G_MEGA_M_S_2 / uscale;
> 
> ...as here we divide 10^6/10^-6 semantically speaking.
> 
Agreed. It makes more sense to call it MICRO.

> > +	step = max / BMI270_MOTION_THRES_FULL_SCALE;
> > +
> > +	return sysfs_emit(buf, "[0 %u %u]\n", step, max);
> > +}
> 
> Is this already documented in ABI?
> 
Not yet. Should this have a device-specific ABI entry?

> -- 
> With Best Regards,
> Andy Shevchenko
> 
> 

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Andy Shevchenko]

On Tue, Jul 15, 2025 at 08:52:41PM -0300, Gustavo Silva wrote:
> On Tue, Jul 15, 2025 at 10:37:21AM +0300, Andy Shevchenko wrote:
> > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:

...

> > Is this already documented in ABI?
> > 
> Not yet. Should this have a device-specific ABI entry?

I don't know, but what I can say is that change is no-go without documented ABI.

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 3/3] iio: imu: bmi270: add support for motion events

[Jonathan Cameron]

On Wed, 16 Jul 2025 12:49:28 +0300
Andy Shevchenko <andriy.shevchenko@intel.com> wrote:

> On Tue, Jul 15, 2025 at 08:52:41PM -0300, Gustavo Silva wrote:
> > On Tue, Jul 15, 2025 at 10:37:21AM +0300, Andy Shevchenko wrote:  
> > > On Fri, Jul 11, 2025 at 08:36:03PM -0300, Gustavo Silva wrote:  
> 
> ...
> 
> > > Is this already documented in ABI?
> > >   
> > Not yet. Should this have a device-specific ABI entry?  
> 
> I don't know, but what I can say is that change is no-go without documented ABI.
> 

Indeed. Seems this particular combination has yet shown up (or we missed
it for docs).  Add appropriate events/in_accel_value_available
entry to Documentation/ABI/sysfs-bus-iio

Whilst you are there, good to check that all the other ABI for this device
is listed in there.  Given we mostly construct ABI from a bunch of parts, it
is easy to miss entries for particular combinations of channel type and thing.

Jonathan