On Tue, 28 Jan 2025 12:00:59 +0000
Lothar Rubusch <l.rubusch@xxxxxxxxx> wrote:
> Add the handling of activity events, also add sysfs entries to
> configure threshold values to trigger the event. Allow to push the
> event over to the iio channel.
>
> Signed-off-by: Lothar Rubusch <l.rubusch@xxxxxxxxx>
I was going to guess these were rate of change detectors or ones
at least slightly compensating for g, but superficially
looks like a straight forward rising mag threshold. Not seeing need
for new ABI.
We've had those interfaces with accelerometers for a long time.
Key is to map the pretty names in the datasheet into what is actually
being detected. That allows for a lot better generalization across manufacturers.
> ---
> drivers/iio/accel/adxl345_core.c | 158 ++++++++++++++++++++++++++++++-
> 1 file changed, 154 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
> index 62d75d28b6fc..94c3ad818ba5 100644
> --- a/drivers/iio/accel/adxl345_core.c
> +++ b/drivers/iio/accel/adxl345_core.c
> @@ -121,6 +121,8 @@
>
> #define ADXL345_REG_TAP_AXIS_MSK GENMASK(2, 0)
> #define ADXL345_REG_TAP_SUPPRESS_MSK BIT(3)
> +#define ADXL345_REG_ACT_AXIS_MSK GENMASK(6, 4)
> +#define ADXL345_REG_ACT_ACDC_MSK BIT(7)
>
> enum adxl345_axis {
> ADXL345_Z_EN = BIT(0),
> @@ -163,6 +165,10 @@ struct adxl345_state {
> u8 watermark;
> u8 fifo_mode;
>
> + u32 act_axis_ctrl;
> + bool act_ac;
> + u8 act_value;
> +
> u32 tap_axis_ctrl;
> u8 tap_threshold;
> u32 tap_duration_us;
> @@ -177,6 +183,11 @@ struct adxl345_state {
> };
>
> static struct iio_event_spec adxl345_events[] = {
> + {
> + /* activity */
> + .type = IIO_EV_TYPE_THRESH,
> + .dir = IIO_EV_DIR_RISING,
> + },
> {
> /* single tap */
> .type = IIO_EV_TYPE_GESTURE,
> @@ -276,6 +287,117 @@ static inline int adxl345_write_interrupts(struct adxl345_state *st)
> return regmap_write(st->regmap, ADXL345_REG_INT_ENABLE, st->int_map);
> }
>
> +/* act/inact */
> +
> +static int adxl345_write_act_axis(struct adxl345_state *st, bool en)
> +{
> + int ret;
> +
> + /*
> + * A setting of 0 selects dc-coupled operation, and a setting of 1
> + * enables ac-coupled operation. In dc-coupled operation, the current
> + * acceleration magnitude is compared directly with THRESH_ACT and
> + * THRESH_INACT to determine whether activity or inactivity is
> + * detected.
> + *
> + * In ac-coupled operation for activity detection, the acceleration
> + * value at the start of activity detection is taken as a reference
> + * value. New samples of acceleration are then compared to this
> + * reference value, and if the magnitude of the difference exceeds the
> + * THRESH_ACT value, the device triggers an activity interrupt.
> + *
> + * Similarly, in ac-coupled operation for inactivity detection, a
> + * reference value is used for comparison and is updated whenever the
> + * device exceeds the inactivity threshold. After the reference value
> + * is selected, the device compares the magnitude of the difference
> + * between the reference value and the current acceleration with
> + * THRESH_INACT. If the difference is less than the value in
> + * THRESH_INACT for the time in TIME_INACT, the device is considered
> + * inactive and the inactivity interrupt is triggered.
> + */
> + ret = regmap_update_bits(st->regmap, ADXL345_REG_ACT_INACT_CTRL,
> + ADXL345_REG_ACT_ACDC_MSK, st->act_ac);
> + if (ret)
> + return ret;
> +
> + /*
> + * The ADXL345 allows for individually enabling/disabling axis for
> + * activity and inactivity detection, respectively. Here both axis are
> + * kept in sync, i.e. an axis will be generally enabled or disabled for
> + * both equally, activity and inactivity detection.
> + */
> + st->act_axis_ctrl = en
> + ? st->act_axis_ctrl | ADXL345_REG_ACT_AXIS_MSK
> + : st->act_axis_ctrl & ~ADXL345_REG_ACT_AXIS_MSK;
> +
> + ret = regmap_update_bits(st->regmap, ADXL345_REG_ACT_INACT_CTRL,
> + ADXL345_REG_ACT_AXIS_MSK,
> + st->act_axis_ctrl);
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static int adxl345_set_act_int(struct adxl345_state *st)
> +{
> + bool args_valid;
> + bool axis_en;
> +
> + axis_en = FIELD_GET(ADXL345_REG_ACT_AXIS_MSK, st->act_axis_ctrl) > 0;
> + args_valid = axis_en && st->act_value > 0;
> + adxl345_intmap_switch_bit(st, args_valid, ADXL345_INT_ACTIVITY);
> +
> + return adxl345_write_interrupts(st);
> +}
> +
> +static int _adxl345_is_act_en(struct adxl345_state *st, bool *en)
> +{
> + int ret;
> + unsigned int regval;
> +
> + ret = adxl345_read_interrupts(st, ®val);
> + if (ret)
> + return ret;
> +
> + *en = FIELD_GET(ADXL345_INT_ACTIVITY, regval) > 0;
> +
> + return 0;
> +}
> +
> +static int _adxl345_set_act_en(struct adxl345_state *st, bool en)
> +{
> + int ret;
> +
> + ret = adxl345_write_act_axis(st, en);
> + if (ret)
> + return ret;
> +
> + return adxl345_set_act_int(st);
> +}
> +
> +static int adxl345_is_act_en(struct adxl345_state *st, bool *en)
> +{
> + return _adxl345_is_act_en(st, en);
> +}
> +
> +static int adxl345_set_act_en(struct adxl345_state *st, bool en)
> +{
> + return _adxl345_set_act_en(st, en);
> +}
> +
> +static int _adxl345_set_act_value(struct adxl345_state *st, u8 val)
> +{
> + st->act_value = val;
> +
> + return regmap_write(st->regmap, ADXL345_REG_THRESH_ACT, val);
> +}
> +
> +static int adxl345_set_act_value(struct adxl345_state *st, u8 val)
> +{
> + return _adxl345_set_act_value(st, val);
> +}
