Allow the debouce counter for transient events to be configured
using the sysfs attribute events/in_accel_thresh_rising_period
Signed-off-by: Martin Fuzzey <mfuzzey@xxxxxxxxxxx>
---
drivers/iio/accel/mma8452.c | 77 ++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 75 insertions(+), 2 deletions(-)
diff --git a/drivers/iio/accel/mma8452.c b/drivers/iio/accel/mma8452.c
index 3415b36..1d1e41b 100644
--- a/drivers/iio/accel/mma8452.c
+++ b/drivers/iio/accel/mma8452.c
@@ -129,6 +129,12 @@ static int mma8452_get_int_plus_micros_index(const int (*vals)[2], int n,
return -EINVAL;
}
+static int mma8452_get_odr_index(struct mma8452_data *data)
+{
+ return (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >>
+ MMA8452_CTRL_DR_SHIFT;
+}
+
static const int mma8452_samp_freq[8][2] = {
{800, 0}, {400, 0}, {200, 0}, {100, 0}, {50, 0}, {12, 500000},
{6, 250000}, {1, 560000}
@@ -144,6 +150,18 @@ static const int mma8452_scales[3][2] = {
{0, 9577}, {0, 19154}, {0, 38307}
};
+/* Datasheet table 35 (step time vs sample frequency) */
+static const int mma8452_transient_time_step_us[8] = {
+ 1250,
+ 2500,
+ 5000,
+ 10000,
+ 20000,
+ 20000,
+ 20000,
+ 20000
+};
+
static ssize_t mma8452_show_samp_freq_avail(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -203,8 +221,7 @@ static int mma8452_read_raw(struct iio_dev *indio_dev,
*val2 = mma8452_scales[i][1];
return IIO_VAL_INT_PLUS_MICRO;
case IIO_CHAN_INFO_SAMP_FREQ:
- i = (data->ctrl_reg1 & MMA8452_CTRL_DR_MASK) >>
- MMA8452_CTRL_DR_SHIFT;
+ i = mma8452_get_odr_index(data);
*val = mma8452_samp_freq[i][0];
*val2 = mma8452_samp_freq[i][1];
return IIO_VAL_INT_PLUS_MICRO;
@@ -356,6 +373,54 @@ static int mma8452_write_event_config(struct iio_dev *indio_dev,
return mma8452_change_config(data, MMA8452_TRANSIENT_CFG, val);
}
+static ssize_t mma8452_query_transient_period(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mma8452_data *data = iio_priv(indio_dev);
+ int us, steps;
+
+ steps = i2c_smbus_read_byte_data(data->client, MMA8452_TRANSIENT_COUNT);
+ if (steps < 0)
+ return steps;
+
+ us = mma8452_transient_time_step_us[mma8452_get_odr_index(data)]
+ * steps;
+
+ return sprintf(buf, "%ld.%06ld\n",
+ us / USEC_PER_SEC, us % USEC_PER_SEC);
+}
+
+static ssize_t mma8452_set_transient_period(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf,
+ size_t len)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct mma8452_data *data = iio_priv(indio_dev);
+ int i, f, us, steps, ret;
+
+ ret = iio_str_to_fixpoint(buf, USEC_PER_SEC / 10, &i, &f);
+ if (ret)
+ return ret;
+ if (ret < 0)
+ return -EINVAL;
+
+ us = i * USEC_PER_SEC + f;
+ steps = us / mma8452_transient_time_step_us[
+ mma8452_get_odr_index(data)];
+
+ if (steps > 0xff)
+ return -EINVAL;
+
+ ret = mma8452_change_config(data, MMA8452_TRANSIENT_COUNT, steps);
+ if (ret)
+ return ret;
+
+ return len;
+}
+
static void mma8452_push_transient_event(struct iio_dev *indio_dev,
int chan, u64 ts)
{
@@ -462,8 +527,16 @@ static const struct iio_event_spec mma8452_transient_event[] = {
*/
static IIO_CONST_ATTR_NAMED(accel_transient_scale, in_accel_scale, "0.617742");
+static IIO_DEVICE_ATTR_NAMED(accel_transient_period,
+ in_accel_thresh_rising_period,
+ S_IRUGO | S_IWUSR,
+ mma8452_query_transient_period,
+ mma8452_set_transient_period,
+ 0);
+
static struct attribute *mma8452_event_attributes[] = {
&iio_const_attr_accel_transient_scale.dev_attr.attr,
+ &iio_dev_attr_accel_transient_period.dev_attr.attr,
NULL,
};
--
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