Add the suppress bit feature to the double tap feature.
Any tap event is defined by a rising signal edge above threshold, i.e.
duration time starts counting; and the falling edge under threshold
within duration time, i.e. then the tap event is issued. This means
duration is used individually for each tap event.
For double tap detection after a single tap, a latency time needs to be
specified. Usually tap events, i.e. spikes above and returning below
threshold will be ignored within latency. After latency, the window
time starts counting for a second tap detection which has to happen
within a duration time.
If the suppress bit is not set, spikes within latency time are ignored.
Setting the suppress bit will invalidate the double tap function. The
sensor will thus be able to save the window time for double tap
detection, and follow a more strict definition of what signal qualifies
for a double tap.
This brings in a new ABI functionality.
---
Q: Perhaps there is already some IIO ABI for it? If not, please let me
know which ABI documentation to extend. There will be a documentation
patch also later in this series.
Signed-off-by: Lothar Rubusch <l.rubusch@xxxxxxxxx>
---
drivers/iio/accel/adxl345_core.c | 82 ++++++++++++++++++++++++++++++++
1 file changed, 82 insertions(+)
diff --git a/drivers/iio/accel/adxl345_core.c b/drivers/iio/accel/adxl345_core.c
index cf35a8f9f432..b6966fee3e3d 100644
--- a/drivers/iio/accel/adxl345_core.c
+++ b/drivers/iio/accel/adxl345_core.c
@@ -34,6 +34,7 @@
#define ADXL345_INT2 1
#define ADXL345_REG_TAP_AXIS_MSK GENMASK(2, 0)
+#define ADXL345_REG_TAP_SUPPRESS_MSK BIT(3)
enum adxl345_axis {
ADXL345_Z_EN = BIT(0),
@@ -81,6 +82,7 @@ struct adxl345_state {
u32 tap_duration_us;
u32 tap_latent_us;
u32 tap_window_us;
+ bool tap_suppressed;
__le16 fifo_buf[ADXL345_DIRS * ADXL345_FIFO_SIZE + 1] __aligned(IIO_DMA_MINALIGN);
};
@@ -243,6 +245,31 @@ 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_is_suppressed_en(struct adxl345_state *st, bool *en)
+{
+ *en = st->tap_suppressed;
+
+ return 0;
+}
+
+static int adxl345_set_suppressed_en(struct adxl345_state *st, bool en)
+{
+ unsigned long regval = 0;
+ int ret;
+
+ en ? __set_bit(ilog2(ADXL345_TAP_SUPPRESS), ®val)
+ : __clear_bit(ilog2(ADXL345_TAP_SUPPRESS), ®val);
+
+ ret = regmap_update_bits(st->regmap, ADXL345_REG_TAP_AXIS,
+ ADXL345_REG_TAP_SUPPRESS_MSK, regval);
+ if (ret)
+ return ret;
+
+ st->tap_suppressed = en;
+
+ return 0;
+}
+
static int adxl345_set_tap_threshold(struct adxl345_state *st, u8 val)
{
int ret;
@@ -616,6 +643,60 @@ static int adxl345_write_raw_get_fmt(struct iio_dev *indio_dev,
}
}
+static ssize_t in_accel_gesture_doubletap_suppressed_en_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct adxl345_state *st = iio_priv(indio_dev);
+ bool en;
+ int val, ret;
+
+ ret = adxl345_is_suppressed_en(st, &en);
+ if (ret)
+ return ret;
+ val = en ? 1 : 0;
+
+ return iio_format_value(buf, IIO_VAL_INT, 1, &val);
+}
+
+static ssize_t in_accel_gesture_doubletap_suppressed_en_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct adxl345_state *st = iio_priv(indio_dev);
+ int val, ret;
+
+ ret = kstrtoint(buf, 0, &val);
+ if (ret)
+ return ret;
+
+ ret = adxl345_set_measure_en(st, false);
+ if (ret)
+ return ret;
+
+ ret = adxl345_set_suppressed_en(st, val > 0);
+ if (ret)
+ return ret;
+
+ ret = adxl345_set_measure_en(st, true);
+ if (ret)
+ return ret;
+
+ return len;
+}
+static IIO_DEVICE_ATTR_RW(in_accel_gesture_doubletap_suppressed_en, 0);
+
+static struct attribute *adxl345_event_attrs[] = {
+ &iio_dev_attr_in_accel_gesture_doubletap_suppressed_en.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group adxl345_event_attrs_group = {
+ .attrs = adxl345_event_attrs,
+};
+
static void adxl345_powerdown(void *ptr)
{
struct adxl345_state *st = ptr;
@@ -899,6 +980,7 @@ static irqreturn_t adxl345_irq_handler(int irq, void *p)
static const struct iio_info adxl345_info = {
.attrs = &adxl345_attrs_group,
+ .event_attrs = &adxl345_event_attrs_group,
.read_raw = adxl345_read_raw,
.write_raw = adxl345_write_raw,
.write_raw_get_fmt = adxl345_write_raw_get_fmt,
--
2.39.5
