On Tue, 28 Jan 2025 12:00:56 +0000
Lothar Rubusch <l.rubusch@xxxxxxxxx> wrote:
> Add the double tap feature of the sensor. The interrupt handler needs
> to catch and forwared the event to the IIO channel. The single tap
> implementation now is extended to deal with double tap as well.
As with earlier patch, new ABI must be documented. Also we need
a strong argument why the existing ABI is not suitable.
Tap detection algorithms are annoyingly specific to manufacturers
but we did make an effort to come up with a general description a
while back so I'd hope perhaps we can map to that.
>
> Signed-off-by: Lothar Rubusch <l.rubusch@xxxxxxxxx>
> ---
> drivers/iio/accel/adxl345_core.c | 139 ++++++++++++++++++++++++++++---
> 1 file changed, 127 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
> index 7831ec511941..f9e5f47ba303 100644
> --- a/drivers/iio/accel/adxl345_core.c
> +++ b/drivers/iio/accel/adxl345_core.c
> @@ -129,6 +129,29 @@ enum adxl345_axis {
> ADXL345_TAP_SUPPRESS = BIT(3),
> };
>
> +/* single/double tap */
> +enum adxl345_tap_type {
> + ADXL345_SINGLE_TAP,
> + ADXL345_DOUBLE_TAP
trailing comma. Maybe there will be a triple tap sometime.
Anyhow, other than 'terminating' entries we should always have trailing commas.
> +};
> +
> +static const unsigned int adxl345_tap_int_reg[2] = {
> + [ADXL345_SINGLE_TAP] = ADXL345_INT_SINGLE_TAP,
> + [ADXL345_DOUBLE_TAP] = ADXL345_INT_DOUBLE_TAP,
> +};
> +
> +enum adxl345_tap_time_type {
> + ADXL345_TAP_TIME_LATENT,
> + ADXL345_TAP_TIME_WINDOW,
> + ADXL345_TAP_TIME_DUR
Comma.
> +};
> +
> +static const unsigned int adxl345_tap_time_reg[3] = {
> + [ADXL345_TAP_TIME_LATENT] = ADXL345_REG_LATENT,
> + [ADXL345_TAP_TIME_WINDOW] = ADXL345_REG_WINDOW,
> + [ADXL345_TAP_TIME_DUR] = ADXL345_REG_DUR,
> +};
> +
> struct adxl345_state {
> const struct adxl345_chip_info *info;
> struct regmap *regmap;
> @@ -142,6 +165,8 @@ struct adxl345_state {
> u32 tap_axis_ctrl;
> u8 tap_threshold;
> u32 tap_duration_us;
> + u32 tap_latent_us;
> + u32 tap_window_us;
>
> __le16 fifo_buf[ADXL345_DIRS * ADXL345_FIFO_SIZE + 1] __aligned(IIO_DMA_MINALIGN);
> };
> @@ -154,6 +179,12 @@ static struct iio_event_spec adxl345_events[] = {
> .mask_separate = BIT(IIO_EV_INFO_ENABLE),
> .mask_shared_by_type = BIT(IIO_EV_INFO_VALUE),
> },
> + {
> + /* double tap */
> + .type = IIO_EV_TYPE_GESTURE,
> + .dir = IIO_EV_DIR_DOUBLETAP,
> + .mask_shared_by_type = BIT(IIO_EV_INFO_ENABLE),
> + },
> };
>
> #define ADXL345_CHANNEL(index, reg, axis) { \
> @@ -250,10 +281,12 @@ static int adxl345_write_tap_axis(struct adxl345_state *st,
> st->tap_axis_ctrl));
> }
>
> -static int adxl345_is_tap_en(struct adxl345_state *st, bool *en)
> +static int adxl345_is_tap_en(struct adxl345_state *st,
> + enum adxl345_tap_type type, bool *en)
> {
> int ret;
> unsigned int regval;
> @@ -280,7 +323,8 @@ static int adxl345_is_tap_en(struct adxl345_state *st, bool *en)
> if (ret)
> return ret;
>
> - *en = FIELD_GET(ADXL345_INT_SINGLE_TAP, regval) > 0;
> + // TODO FIELD_GET() seems not possible here due to construct 'not const', any ideas?
There is a new function to solve this proposed on list, but not upstream yet.
For now roll your own as you have done.
> + *en = (adxl345_tap_int_reg[type] & regval) > 0;
>
> return 0;
> }
> @@ -294,7 +338,12 @@ static int adxl345_set_singletap_en(struct adxl345_state *st,
> if (ret)
> return ret;
>
> - return _adxl345_set_tap_int(st, en);
> + return _adxl345_set_tap_int(st, ADXL345_SINGLE_TAP, en);
> +}
> +
> +static int adxl345_set_doubletap_en(struct adxl345_state *st, bool en)
> +{
> + return _adxl345_set_tap_int(st, ADXL345_DOUBLE_TAP, en);
> }
>
> static int adxl345_set_tap_value(struct adxl345_state *st, u8 val)
> @@ -304,19 +353,33 @@ static int adxl345_set_tap_value(struct adxl345_state *st, u8 val)
> return regmap_write(st->regmap, ADXL345_REG_THRESH_TAP, min(val, 0xFF));
> }
>
> -static int _adxl345_set_tap_time(struct adxl345_state *st, u32 val_us)
> +static int _adxl345_set_tap_time(struct adxl345_state *st,
> + enum adxl345_tap_time_type type, u32 val_us)
> {
> unsigned int regval;
>
> - st->tap_duration_us = val_us;
> + switch (type) {
> + case ADXL345_TAP_TIME_WINDOW:
> + st->tap_window_us = val_us;
> + break;
> + case ADXL345_TAP_TIME_LATENT:
> + st->tap_latent_us = val_us;
> + break;
> + case ADXL345_TAP_TIME_DUR:
> + st->tap_duration_us = val_us;
> + break;
> + }
>
> /*
> * The scale factor is 1250us / LSB for tap_window_us and tap_latent_us.
> * For tap_duration_us the scale factor is 625us / LSB.
> */
> - regval = DIV_ROUND_CLOSEST(val_us, 625);
> + if (type == ADXL345_TAP_TIME_DUR)
> + regval = DIV_ROUND_CLOSEST(val_us, 625);
> + else
> + regval = DIV_ROUND_CLOSEST(val_us, 1250);
>
> - return regmap_write(st->regmap, ADXL345_REG_DUR, regval);
> + return regmap_write(st->regmap, adxl345_tap_time_reg[type], regval);
Use this in the earlier patch, even though it would only have one entry at that point.
There is little point in introducing infrastructure that rewrites a patch
just after that patch. Just put it in the first one with a note
saying it is useful shortly.
> }
>
> static int adxl345_set_tap_duration(struct adxl345_state *st, u32 val_int,
> @@ -330,7 +393,35 @@ static int adxl345_set_tap_duration(struct adxl345_state *st, u32 val_int,
> if (val_int || val_fract_us > 159375)
> return -EINVAL;
>
> - return _adxl345_set_tap_time(st, val_fract_us);
> + return _adxl345_set_tap_time(st, ADXL345_TAP_TIME_DUR, val_fract_us);
> +}
> @@ -637,9 +735,13 @@ static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
> static IIO_DEVICE_ATTR_RW(in_accel_##A##_##C##_##E, 0)
>
> ADXL345_generate_iio_dev_attr_FRACTIONAL(gesture_singletap, tap, duration, MICRO, us);
> +ADXL345_generate_iio_dev_attr_FRACTIONAL(gesture_doubletap, tap, window, MICRO, us);
> +ADXL345_generate_iio_dev_attr_FRACTIONAL(gesture_doubletap, tap, latent, MICRO, us);
>
> static struct attribute *adxl345_event_attrs[] = {
> &iio_dev_attr_in_accel_gesture_singletap_duration_us.dev_attr.attr,
> + &iio_dev_attr_in_accel_gesture_doubletap_latent_us.dev_attr.attr,
> + &iio_dev_attr_in_accel_gesture_doubletap_window_us.dev_attr.attr,
As above. ABI docs missing and times in IIO are all seconds. us to seconds is easy
given you just use the formatting functions and pass val == 0.
> NULL
> };
>
> @@ -861,6 +963,17 @@ static int adxl345_push_event(struct iio_dev *indio_dev, int int_stat,
> return ret;
> }
>
> + if (FIELD_GET(ADXL345_INT_DOUBLE_TAP, int_stat)) {
> + ret = iio_push_event(indio_dev,
> + IIO_MOD_EVENT_CODE(IIO_ACCEL, 0,
> + act_tap_dir,
> + IIO_EV_TYPE_GESTURE,
> + IIO_EV_DIR_DOUBLETAP),
> + ts);
> + if (ret)
> + return ret;
> + }
> +
> return -ENOENT;
> }
>
> @@ -965,6 +1078,8 @@ int adxl345_core_probe(struct device *dev, struct regmap *regmap,
> /* Init with reasonable values */
> st->tap_threshold = 35; /* 35 [0x23] */
> st->tap_duration_us = 3; /* 3 [0x03] -> .001875 */
> + st->tap_window_us = 20; /* 20 [0x14] -> .025 */
> + st->tap_latent_us = 20; /* 20 [0x14] -> .025 */
>
> indio_dev->name = st->info->name;
> indio_dev->info = &adxl345_info;
