Re: [PATCH v5 10/11] iio: accel: adxl345: add coupling detection for activity/inactivity

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 18 Mar 2025 23:08:42 +0000
Lothar Rubusch <l.rubusch@gmail.com> wrote:

> Add coupling activity/inactivity detection by the AC/DC bit. This is an
> addititional enhancement for the detection of activity states and
> completes the activity / inactivity feature of the ADXL345.
> 
> Signed-off-by: Lothar Rubusch <l.rubusch@gmail.com>
> ---

> @@ -300,6 +319,69 @@ static int adxl345_set_measure_en(struct adxl345_state *st, bool en)
>  
>  /* act/inact */
>  
> +static int adxl345_is_act_inact_ac(struct adxl345_state *st,
> +				   enum adxl345_activity_type type, bool *ac)
> +{
> +	unsigned int regval;
> +	int ret;
> +
> +	ret = regmap_read(st->regmap, ADXL345_REG_ACT_INACT_CTRL, &regval);
> +	if (ret)
> +		return ret;
> +
> +	if (type == ADXL345_ACTIVITY)
> +		*ac = (FIELD_GET(ADXL345_REG_ACT_ACDC_MSK, regval) > 0);
> +	else
> +		*ac = (FIELD_GET(ADXL345_REG_INACT_ACDC_MSK, regval) > 0);

The > 0 doesn't add anything so I'd drop those.
Get used to non 0 integer == true for booleans takes some time but
is commonly assumed in kernel code (it is true in C in general but
some coding styles don't assume it!)

> +
> +	return 0;
> +}


>  static int adxl345_read_avail(struct iio_dev *indio_dev,
> @@ -919,6 +1050,8 @@ static int adxl345_read_event_config(struct iio_dev *indio_dev,
>  {
>  	struct adxl345_state *st = iio_priv(indio_dev);
>  	bool int_en;
> +	bool act_ac;
> +	bool inact_ac;
Could stick those 3 bools on one line without loosing readability I think.
Save a tiny bit of scrolling ;)
or push them down to context where they are used.


>  	int ret;
>  
>  	switch (type) {
> @@ -963,6 +1096,21 @@ static int adxl345_read_event_config(struct iio_dev *indio_dev,
>  		if (ret)
>  			return ret;
>  		return int_en;
> +	case IIO_EV_TYPE_MAG_REFERENCED:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			ret = adxl345_is_act_inact_ac(st, ADXL345_ACTIVITY, &act_ac);
> +			if (ret)
> +				return ret;
> +			return act_ac;
> +		case IIO_EV_DIR_FALLING:
> +			ret = adxl345_is_act_inact_ac(st, ADXL345_INACTIVITY, &inact_ac);
> +			if (ret)
> +				return ret;
> +			return inact_ac;
> +		default:
> +			return -EINVAL;
> +		}
>  	default:
>  		return -EINVAL;
>  	}
> @@ -999,6 +1147,16 @@ static int adxl345_write_event_config(struct iio_dev *indio_dev,
>  		}
>  	case IIO_EV_TYPE_MAG:
>  		return adxl345_set_ff_en(st, state);
> +	case IIO_EV_TYPE_MAG_REFERENCED:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			return adxl345_set_act_inact_ac(st, ADXL345_ACTIVITY, state);
> +		case IIO_EV_DIR_FALLING:
> +			return adxl345_set_act_inact_ac(st, ADXL345_INACTIVITY, state);
> +		default:
> +			return -EINVAL;
> +		}
> +
>  	default:
>  		return -EINVAL;
>  	}