[PATCH v2 4/4] iio: light: ltr390: Add interrupt persistance support

Abhash Jha
2024-09-10T04:51:49Z

Added support to configure the threshold interrupt persistance value by
providing IIO_EV_INFO_PERIOD attribute. The value written to the
attribute should be in miliseconds and should be greater than the
sampling rate of the sensor.

Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
---
drivers/iio/light/ltr390.c | 66 +++++++++++++++++++++++++++++++++++---
1 file changed, 62 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/light/ltr390.c b/drivers/iio/light/ltr390.c
index 8a8a118ca..9706105c6 100644
--- a/drivers/iio/light/ltr390.c
+++ b/drivers/iio/light/ltr390.c
@@ -40,6 +40,7 @@
#define LTR390_ALS_DATA 0x0D
#define LTR390_UVS_DATA 0x10
#define LTR390_INT_CFG 0x19
+#define LTR390_INT_PST 0x1A
#define LTR390_THRESH_UP 0x21
#define LTR390_THRESH_LOW 0x24

@@ -48,6 +49,8 @@
#define LTR390_ALS_UVS_MEAS_RATE_MASK 0x07
#define LTR390_ALS_UVS_INT_TIME_MASK 0x70
#define LTR390_ALS_UVS_INT_TIME(x) FIELD_PREP(LTR390_ALS_UVS_INT_TIME_MASK, (x))
+#define LTR390_INT_PST_MASK 0xF0
+#define LTR390_INT_PST_VAL(x) FIELD_PREP(LTR390_INT_PST_MASK, (x))

#define LTR390_SW_RESET BIT(4)
#define LTR390_UVS_MODE BIT(3)
@@ -79,6 +82,11 @@ enum ltr390_mode {
LTR390_SET_UVS_MODE,
};

+enum ltr390_meas_rate {
+ LTR390_GET_FREQ,
+ LTR390_GET_PERIOD,
+};
+
struct ltr390_data {
struct regmap *regmap;
struct i2c_client *client;
@@ -156,7 +164,7 @@ static int ltr390_counts_per_uvi(struct ltr390_data *data)
return DIV_ROUND_CLOSEST(23 * data->gain * data->int_time_us, 10 * orig_gain * orig_int_time);
}

-static int ltr390_get_samp_freq(struct ltr390_data *data)
+static int ltr390_get_samp_freq_or_period(struct ltr390_data *data, enum ltr390_meas_rate option)
{
int ret, value;

@@ -165,7 +173,7 @@ static int ltr390_get_samp_freq(struct ltr390_data *data)
return ret;
value &= LTR390_ALS_UVS_MEAS_RATE_MASK;

- return ltr390_samp_freq_table[value][0];
+ return ltr390_samp_freq_table[value][option];
}

static int ltr390_read_raw(struct iio_dev *iio_device,
@@ -225,7 +233,7 @@ static int ltr390_read_raw(struct iio_dev *iio_device,
return IIO_VAL_INT;

case IIO_CHAN_INFO_SAMP_FREQ:
- *val = ltr390_get_samp_freq(data);
+ *val = ltr390_get_samp_freq_or_period(data, LTR390_GET_FREQ);
return IIO_VAL_INT;

default:
@@ -250,7 +258,8 @@ static const struct iio_event_spec ltr390_event_spec[] = {
}, {
.type = IIO_EV_TYPE_THRESH,
.dir = IIO_EV_DIR_EITHER,
- .mask_separate = BIT(IIO_EV_INFO_ENABLE),
+ .mask_separate = BIT(IIO_EV_INFO_ENABLE) |
+ BIT(IIO_EV_INFO_PERIOD),
}
};

@@ -398,6 +407,44 @@ static int ltr390_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec cons
}
}

+static int ltr390_read_intr_prst(struct ltr390_data *data, int *val)
+{
+ int ret, prst, samp_period;
+
+ samp_period = ltr390_get_samp_freq_or_period(data, LTR390_GET_PERIOD);
+ ret = regmap_read(data->regmap, LTR390_INT_PST, &prst);
+ if (ret < 0)
+ return ret;
+ *val = prst * samp_period;
+
+ return IIO_VAL_INT;
+}
+
+static int ltr390_write_intr_prst(struct ltr390_data *data, int val)
+{
+ int ret, samp_period, new_val;
+
+ samp_period = ltr390_get_samp_freq_or_period(data, LTR390_GET_PERIOD);
+
+ /* persist period should be greater than or equal to samp period */
+ if (val < samp_period)
+ return -EINVAL;
+
+ new_val = DIV_ROUND_UP(val, samp_period);
+ if (new_val < 0 || new_val > 0x0f)
+ return -EINVAL;
+
+ guard(mutex)(&data->lock);
+ ret = regmap_update_bits(data->regmap,
+ LTR390_INT_PST,
+ LTR390_INT_PST_MASK,
+ LTR390_INT_PST_VAL(new_val));
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
static int ltr390_read_threshold(const struct iio_dev *indio_dev,
enum iio_event_direction dir,
int *val, int *val2)
@@ -458,6 +505,10 @@ static int ltr390_read_event_value(struct iio_dev *indio_dev,
switch (info) {
case IIO_EV_INFO_VALUE:
return ltr390_read_threshold(indio_dev, dir, val, val2);
+
+ case IIO_EV_INFO_PERIOD:
+ return ltr390_read_intr_prst(iio_priv(indio_dev), val);
+
default:
return -EINVAL;
}
@@ -476,6 +527,13 @@ static int ltr390_write_event_value(struct iio_dev *indio_dev,
return -EINVAL;

return ltr390_write_threshold(indio_dev, dir, val, val2);
+
+ case IIO_EV_INFO_PERIOD:
+ if (val2 != 0)
+ return -EINVAL;
+
+ return ltr390_write_intr_prst(iio_priv(indio_dev), val);
+
default:
return -EINVAL;
}
--
2.43.0