iio: accel: bma400: Add separate channel for step counter

Added channel for step counter which can be enable or disable
through the sysfs interface.

Signed-off-by: Jagath Jog J <jagathjog1996@gmail.com>

drivers/iio/accel/bma400.h

@@ -53,6 +53,7 @@
 #define BMA400_STEP_CNT1_REG        0x16
 #define BMA400_STEP_CNT3_REG        0x17
 #define BMA400_STEP_STAT_REG        0x18
+#define BMA400_STEP_INT_MSK         BIT(0)
 
 /*
  * Read-write configuration registers

drivers/iio/accel/bma400_core.c

@@ -68,6 +68,7 @@ struct bma400_data {
 	int oversampling_ratio;
 	int scale;
 	struct iio_trigger *trig;
+	int steps_enabled;
 	/* Correct time stamp alignment */
 	struct {
 		__be16 buff[3];
@@ -202,6 +203,13 @@ static const struct iio_chan_spec bma400_channels[] = {
 			.endianness = IIO_LE,
 		},
 	},
+	{
+		.type = IIO_STEPS,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
+				      BIT(IIO_CHAN_INFO_ENABLE),
+		.scan_index = -1, /* No buffer support */
+	},
+
 	IIO_CHAN_SOFT_TIMESTAMP(4),
 };
 
@@ -686,13 +694,28 @@ static int bma400_read_raw(struct iio_dev *indio_dev,
 {
 	struct bma400_data *data = iio_priv(indio_dev);
 	int ret;
+	u32 steps_raw;
 
 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED:
-		mutex_lock(&data->mutex);
-		ret = bma400_get_temp_reg(data, val, val2);
-		mutex_unlock(&data->mutex);
-		return ret;
+		switch (chan->type) {
+		case IIO_STEPS:
+			mutex_lock(&data->mutex);
+			ret = regmap_bulk_read(data->regmap, BMA400_STEP_CNT0_REG,
+					       &steps_raw, 3 * sizeof(u8));
+			mutex_unlock(&data->mutex);
+			if (ret)
+				return ret;
+			*val = steps_raw & 0x00FFFFFF;
+			return IIO_VAL_INT;
+		case IIO_TEMP:
+			mutex_lock(&data->mutex);
+			ret = bma400_get_temp_reg(data, val, val2);
+			mutex_unlock(&data->mutex);
+			return ret;
+		default:
+			return -EINVAL;
+		}
 	case IIO_CHAN_INFO_RAW:
 		mutex_lock(&data->mutex);
 		ret = bma400_get_accel_reg(data, chan, val);
@@ -733,6 +756,9 @@ static int bma400_read_raw(struct iio_dev *indio_dev,
 
 		*val = data->oversampling_ratio;
 		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_ENABLE:
+		*val = data->steps_enabled;
+		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
 	}
@@ -798,6 +824,17 @@ static int bma400_write_raw(struct iio_dev *indio_dev,
 		ret = bma400_set_accel_oversampling_ratio(data, val);
 		mutex_unlock(&data->mutex);
 		return ret;
+	case IIO_CHAN_INFO_ENABLE:
+		if (data->steps_enabled == val)
+			return 0;
+
+		mutex_lock(&data->mutex);
+		ret = regmap_update_bits(data->regmap, BMA400_INT_CONFIG1_REG,
+					 BMA400_STEP_INT_MSK,
+					 FIELD_PREP(BMA400_STEP_INT_MSK, !!val));
+		mutex_unlock(&data->mutex);
+		data->steps_enabled = val;
+		return ret;
 	default:
 		return -EINVAL;
 	}
@@ -814,6 +851,8 @@ static int bma400_write_raw_get_fmt(struct iio_dev *indio_dev,
 		return IIO_VAL_INT_PLUS_MICRO;
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_ENABLE:
+		return IIO_VAL_INT;
 	default:
 		return -EINVAL;
 	}