[PATCH 0/4] Threshold event and Sampling freq support for LTR390

[PATCH 0/4] Threshold event and Sampling freq support for LTR390

[Abhash Jha]

Hello,

The first patch adds support for configuring the Sampling frequency of
the sensor. The available values for the sampling freqeuncy are provided
by the `read_avail` callback and they are in miliHertz.

Then the second patch adds support for suspending and resuming
the sensor by providing the necessary callbacks. And registering
the ops with the driver.

The third patch in the series adds support for Threshold events and interrupts.
Exposed rising and falling threshold events for both the channels. The events
can be configured via the write_event_config callback. The desired rising or falling
threshold value can be written to from userspace.

The fourth patch adds support for threshold interrupt persistance.
It triggers when the UVS/ALS data is out of thresholds for a specific number
of consecutive measurements.
Exposed the IIO_EV_INFO_PERIOD attribute by which userspace can set the persistance
value in miliseconds. The persistance period should be greater than or equal
to the sampling period.

Thanks,
Abhash

Abhash Jha (4):
  iio: light: ltr390: Added configurable sampling frequency support
  iio: light: ltr390: Suspend and Resume support
  iio: light: ltr390: Interrupts and threshold event support
  iio: light: ltr390: Add interrupt persistance support

 drivers/iio/light/ltr390.c | 361 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 359 insertions(+), 2 deletions(-)

-- 
2.43.0

[PATCH 1/4] iio: light: ltr390: Added configurable sampling frequency support

[Abhash Jha]

Provied configurable sampling frequency(Measurement rate) support.
Also exposed the available sampling frequency values using read_avail
callback.

Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
---
 drivers/iio/light/ltr390.c | 68 ++++++++++++++++++++++++++++++++++++--
 1 file changed, 66 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/light/ltr390.c b/drivers/iio/light/ltr390.c
index 7e58b50f3..73ef4a5a0 100644
--- a/drivers/iio/light/ltr390.c
+++ b/drivers/iio/light/ltr390.c
@@ -39,6 +39,7 @@
 
 #define LTR390_PART_NUMBER_ID		0xb
 #define LTR390_ALS_UVS_GAIN_MASK	0x07
+#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))
 
@@ -87,6 +88,18 @@ static const struct regmap_config ltr390_regmap_config = {
 	.val_bits = 8,
 };
 
+/* Sampling frequency is in mili Hz and mili Seconds */
+static const int ltr390_samp_freq_table[][2] = {
+		[0] = {40000, 25},
+		[1] = {20000, 50},
+		[2] = {10000, 100},
+		[3] = {5000, 200},
+		[4] = {2000, 500},
+		[5] = {1000, 1000},
+		[6] = {500, 2000},
+		[7] = {500, 2000}
+};
+
 static int ltr390_register_read(struct ltr390_data *data, u8 register_address)
 {
 	struct device *dev = &data->client->dev;
@@ -135,6 +148,18 @@ 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)
+{
+	int ret, value;
+
+	ret = regmap_read(data->regmap, LTR390_ALS_UVS_MEAS_RATE, &value);
+	if (ret < 0)
+		return ret;
+	value &= LTR390_ALS_UVS_MEAS_RATE_MASK;
+
+	return ltr390_samp_freq_table[value][0];
+}
+
 static int ltr390_read_raw(struct iio_dev *iio_device,
 			   struct iio_chan_spec const *chan, int *val,
 			   int *val2, long mask)
@@ -191,6 +216,10 @@ static int ltr390_read_raw(struct iio_dev *iio_device,
 		*val = data->int_time_us;
 		return IIO_VAL_INT;
 
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*val = ltr390_get_samp_freq(data);
+		return IIO_VAL_INT;
+
 	default:
 		return -EINVAL;
 	}
@@ -199,6 +228,7 @@ static int ltr390_read_raw(struct iio_dev *iio_device,
 /* integration time in us */
 static const int ltr390_int_time_map_us[] = { 400000, 200000, 100000, 50000, 25000, 12500 };
 static const int ltr390_gain_map[] = { 1, 3, 6, 9, 18 };
+static const int ltr390_freq_map[] = { 40000, 20000, 10000, 5000, 2000, 1000, 500, 500 };
 
 static const struct iio_chan_spec ltr390_channels[] = {
 	/* UV sensor */
@@ -206,16 +236,18 @@ static const struct iio_chan_spec ltr390_channels[] = {
 		.type = IIO_UVINDEX,
 		.scan_index = 0,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
-		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SCALE)
+						| BIT(IIO_CHAN_INFO_SAMP_FREQ)
 	},
 	/* ALS sensor */
 	{
 		.type = IIO_LIGHT,
 		.scan_index = 1,
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
-		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME),
+		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SCALE)
+						| BIT(IIO_CHAN_INFO_SAMP_FREQ)
 	},
 };
 
@@ -264,6 +296,27 @@ static int ltr390_set_int_time(struct ltr390_data *data, int val)
 	return -EINVAL;
 }
 
+static int ltr390_set_samp_freq(struct ltr390_data *data, int val)
+{
+	int ret, idx;
+
+	for (idx = 0; idx < ARRAY_SIZE(ltr390_samp_freq_table); idx++) {
+		if (ltr390_samp_freq_table[idx][0] != val)
+			continue;
+
+		guard(mutex)(&data->lock);
+		ret = regmap_update_bits(data->regmap,
+					LTR390_ALS_UVS_MEAS_RATE,
+					LTR390_ALS_UVS_MEAS_RATE_MASK, idx);
+		if (ret)
+			return ret;
+
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
 static int ltr390_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
 				const int **vals, int *type, int *length, long mask)
 {
@@ -278,6 +331,11 @@ static int ltr390_read_avail(struct iio_dev *indio_dev, struct iio_chan_spec con
 		*type = IIO_VAL_INT;
 		*vals = ltr390_int_time_map_us;
 		return IIO_AVAIL_LIST;
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		*length = ARRAY_SIZE(ltr390_freq_map);
+		*type = IIO_VAL_INT;
+		*vals = ltr390_freq_map;
+		return IIO_AVAIL_LIST;
 	default:
 		return -EINVAL;
 	}
@@ -301,6 +359,12 @@ static int ltr390_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec cons
 
 		return ltr390_set_int_time(data, val);
 
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		if (val2 != 0)
+			return -EINVAL;
+
+		return ltr390_set_samp_freq(data, val);
+
 	default:
 		return -EINVAL;
 	}
-- 
2.43.0

[PATCH 2/4] iio: light: ltr390: Suspend and Resume support

[Abhash Jha]

Added support for suspend and resume PM ops.
We suspend the sensor by clearing the ALS_UVS_EN bit in the MAIN CONTROL
register. And we resume it by setting that bit.

Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
---
 drivers/iio/light/ltr390.c | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/drivers/iio/light/ltr390.c b/drivers/iio/light/ltr390.c
index 73ef4a5a0..c4ff26d68 100644
--- a/drivers/iio/light/ltr390.c
+++ b/drivers/iio/light/ltr390.c
@@ -432,6 +432,24 @@ static int ltr390_probe(struct i2c_client *client)
 	return devm_iio_device_register(dev, indio_dev);
 }
 
+static int ltr390_suspend(struct device *dev)
+{
+	struct ltr390_data *data = iio_priv(i2c_get_clientdata(
+						to_i2c_client(dev)));
+
+	return regmap_clear_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
+}
+
+static int ltr390_resume(struct device *dev)
+{
+	struct ltr390_data *data = iio_priv(i2c_get_clientdata(
+						to_i2c_client(dev)));
+
+	return regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(ltr390_pm_ops, ltr390_suspend, ltr390_resume);
+
 static const struct i2c_device_id ltr390_id[] = {
 	{ "ltr390" },
 	{ /* Sentinel */ }
@@ -448,6 +466,7 @@ static struct i2c_driver ltr390_driver = {
 	.driver = {
 		.name = "ltr390",
 		.of_match_table = ltr390_of_table,
+		.pm	= pm_sleep_ptr(&ltr390_pm_ops),
 	},
 	.probe = ltr390_probe,
 	.id_table = ltr390_id,
-- 
2.43.0

[PATCH 3/4] iio: light: ltr390: Interrupts and threshold event support

[Abhash Jha]

Added support for threshold events for both the ALS and UVI channels.
The events are reported when the threshold interrupt is triggered. Both
rising and falling threshold types are supported.

Signed-off-by: Abhash Jha <abhashkumarjha123@gmail.com>
---
 drivers/iio/light/ltr390.c | 220 ++++++++++++++++++++++++++++++++++++-
 1 file changed, 218 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/light/ltr390.c b/drivers/iio/light/ltr390.c
index c4ff26d68..c707a4871 100644
--- a/drivers/iio/light/ltr390.c
+++ b/drivers/iio/light/ltr390.c
@@ -26,6 +26,7 @@
 #include <linux/bitfield.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/events.h>
 
 #include <asm/unaligned.h>
 
@@ -33,9 +34,12 @@
 #define LTR390_ALS_UVS_MEAS_RATE	0x04
 #define LTR390_ALS_UVS_GAIN		0x05
 #define LTR390_PART_ID			0x06
+#define LTR390_MAIN_STATUS		0x07
 #define LTR390_ALS_DATA			0x0D
 #define LTR390_UVS_DATA			0x10
 #define LTR390_INT_CFG			0x19
+#define LTR390_THRESH_UP		0x21
+#define LTR390_THRESH_LOW		0x24
 
 #define LTR390_PART_NUMBER_ID		0xb
 #define LTR390_ALS_UVS_GAIN_MASK	0x07
@@ -46,6 +50,8 @@
 #define LTR390_SW_RESET	      BIT(4)
 #define LTR390_UVS_MODE	      BIT(3)
 #define LTR390_SENSOR_ENABLE  BIT(1)
+#define LTR390_LS_INT_EN      BIT(2)
+#define LTR390_LS_INT_SEL_UVS BIT(5)
 
 #define LTR390_FRACTIONAL_PRECISION 100
 
@@ -230,6 +236,22 @@ static const int ltr390_int_time_map_us[] = { 400000, 200000, 100000, 50000, 250
 static const int ltr390_gain_map[] = { 1, 3, 6, 9, 18 };
 static const int ltr390_freq_map[] = { 40000, 20000, 10000, 5000, 2000, 1000, 500, 500 };
 
+static const struct iio_event_spec ltr390_event_spec[] = {
+	{
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_RISING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_FALLING,
+		.mask_separate = BIT(IIO_EV_INFO_VALUE),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	}
+};
+
 static const struct iio_chan_spec ltr390_channels[] = {
 	/* UV sensor */
 	{
@@ -238,7 +260,9 @@ static const struct iio_chan_spec ltr390_channels[] = {
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SCALE)
-						| BIT(IIO_CHAN_INFO_SAMP_FREQ)
+						| BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.event_spec = ltr390_event_spec,
+		.num_event_specs = ARRAY_SIZE(ltr390_event_spec),
 	},
 	/* ALS sensor */
 	{
@@ -247,7 +271,9 @@ static const struct iio_chan_spec ltr390_channels[] = {
 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | BIT(IIO_CHAN_INFO_SCALE),
 		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		.info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME) | BIT(IIO_CHAN_INFO_SCALE)
-						| BIT(IIO_CHAN_INFO_SAMP_FREQ)
+						| BIT(IIO_CHAN_INFO_SAMP_FREQ),
+		.event_spec = ltr390_event_spec,
+		.num_event_specs = ARRAY_SIZE(ltr390_event_spec),
 	},
 };
 
@@ -370,12 +396,186 @@ static int ltr390_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec cons
 	}
 }
 
+static int ltr390_read_threshold(const struct iio_dev *indio_dev,
+				enum iio_event_direction dir,
+				int *val, int *val2)
+{
+	struct ltr390_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (dir) {
+	case IIO_EV_DIR_RISING:
+		ret = ltr390_register_read(data, LTR390_THRESH_UP);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+
+	case IIO_EV_DIR_FALLING:
+		ret = ltr390_register_read(data, LTR390_THRESH_LOW);
+		if (ret < 0)
+			return ret;
+		*val = ret;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltr390_write_threshold(struct iio_dev *indio_dev,
+				enum iio_event_direction dir,
+				int val, int val2)
+{
+	struct ltr390_data *data = iio_priv(indio_dev);
+	int ret;
+
+	guard(mutex)(&data->lock);
+	switch (dir) {
+	case IIO_EV_DIR_RISING:
+		ret = regmap_bulk_write(data->regmap,
+					LTR390_THRESH_UP,
+					&val, 3);
+		return ret;
+	case IIO_EV_DIR_FALLING:
+		ret = regmap_bulk_write(data->regmap,
+					LTR390_THRESH_LOW,
+					&val, 3);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltr390_read_event_value(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				enum iio_event_type type,
+				enum iio_event_direction dir,
+				enum iio_event_info info,
+				int *val, int *val2)
+{
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		return ltr390_read_threshold(indio_dev, dir, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltr390_write_event_value(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				enum iio_event_type type,
+				enum iio_event_direction dir,
+				enum iio_event_info info,
+				int val, int val2)
+{
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		if (val2 != 0)
+			return -EINVAL;
+
+		return ltr390_write_threshold(indio_dev, dir, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int ltr390_read_event_config(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				enum iio_event_type type,
+				enum iio_event_direction dir)
+{
+	struct ltr390_data *data = iio_priv(indio_dev);
+	int ret, status;
+
+	ret = regmap_read(data->regmap, LTR390_INT_CFG, &status);
+	if (ret < 0)
+		return ret;
+
+	return status & LTR390_LS_INT_EN;
+}
+
+static int ltr390_write_event_config(struct iio_dev *indio_dev,
+				const struct iio_chan_spec *chan,
+				enum iio_event_type type,
+				enum iio_event_direction dir,
+				int state)
+{
+	struct ltr390_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (state != 1  && state != 0)
+		return -EINVAL;
+
+	if (state == 0)
+		return regmap_clear_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_EN);
+
+	guard(mutex)(&data->lock);
+	ret = regmap_set_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_EN);
+	if (ret < 0)
+		return ret;
+
+	switch (chan->type) {
+	case IIO_LIGHT:
+		ret = ltr390_set_mode(data, LTR390_SET_ALS_MODE);
+		if (ret < 0)
+			return ret;
+
+		return regmap_clear_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_SEL_UVS);
+
+	case IIO_UVINDEX:
+		ret = ltr390_set_mode(data, LTR390_SET_UVS_MODE);
+		if (ret < 0)
+			return ret;
+
+		return regmap_set_bits(data->regmap, LTR390_INT_CFG, LTR390_LS_INT_SEL_UVS);
+
+	default:
+		return -EINVAL;
+	}
+}
+
 static const struct iio_info ltr390_info = {
 	.read_raw = ltr390_read_raw,
 	.write_raw = ltr390_write_raw,
 	.read_avail = ltr390_read_avail,
+	.read_event_value = ltr390_read_event_value,
+	.read_event_config = ltr390_read_event_config,
+	.write_event_value = ltr390_write_event_value,
+	.write_event_config = ltr390_write_event_config,
 };
 
+static irqreturn_t ltr390_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct ltr390_data *data = iio_priv(indio_dev);
+	int ret, status;
+
+	/* Reading the status register to clear the interrupt flag, Datasheet pg: 17*/
+	ret = regmap_read(data->regmap, LTR390_MAIN_STATUS, &status);
+	if (ret < 0)
+		return ret;
+
+	switch (data->mode) {
+	case LTR390_SET_ALS_MODE:
+		iio_push_event(indio_dev,
+			IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
+			IIO_EV_TYPE_THRESH,
+			IIO_EV_DIR_EITHER),
+			iio_get_time_ns(indio_dev));
+		break;
+
+	case LTR390_SET_UVS_MODE:
+		iio_push_event(indio_dev,
+			IIO_UNMOD_EVENT_CODE(IIO_UVINDEX, 0,
+			IIO_EV_TYPE_THRESH,
+			IIO_EV_DIR_EITHER),
+			iio_get_time_ns(indio_dev));
+		break;
+	}
+
+	return IRQ_HANDLED;
+}
+
 static int ltr390_probe(struct i2c_client *client)
 {
 	struct ltr390_data *data;
@@ -429,6 +629,22 @@ static int ltr390_probe(struct i2c_client *client)
 	if (ret)
 		return dev_err_probe(dev, ret, "failed to enable the sensor\n");
 
+	if (client->irq) {
+		int irq_flags = irq_get_trigger_type(client->irq);
+
+		if (!irq_flags)
+			irq_flags = IRQF_TRIGGER_FALLING;
+
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, ltr390_interrupt_handler,
+						irq_flags | IRQF_ONESHOT,
+						"ltr390_thresh_event", indio_dev);
+		if (ret) {
+			dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
+			return ret;
+		}
+	}
+
 	return devm_iio_device_register(dev, indio_dev);
 }
 
-- 
2.43.0

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

[Abhash Jha]

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 c707a4871..87195f001 100644
--- a/drivers/iio/light/ltr390.c
+++ b/drivers/iio/light/ltr390.c
@@ -38,6 +38,7 @@
 #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
 
@@ -46,6 +47,8 @@
 #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)
@@ -77,6 +80,11 @@ 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;
@@ -154,7 +162,7 @@ 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;
 
@@ -163,7 +171,7 @@ 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,
@@ -223,7 +231,7 @@ 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:
@@ -248,7 +256,8 @@ 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),
 	}
 };
 
@@ -396,6 +405,44 @@ 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)
@@ -456,6 +503,10 @@ 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;
 	}
@@ -474,6 +525,13 @@ 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

Re: [PATCH 3/4] iio: light: ltr390: Interrupts and threshold event support

[kernel test robot]

Hi Abhash,

kernel test robot noticed the following build errors:

[auto build test ERROR on jic23-iio/togreg]
[also build test ERROR on next-20240909]
[cannot apply to linus/master v6.11-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Abhash-Jha/iio-light-ltr390-Suspend-and-Resume-support/20240909-193623
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20240909103623.264113-4-abhashkumarjha123%40gmail.com
patch subject: [PATCH 3/4] iio: light: ltr390: Interrupts and threshold event support
config: x86_64-buildonly-randconfig-003-20240910 (https://download.01.org/0day-ci/archive/20240910/202409100717.2rKMS0oi-lkp@intel.com/config)
compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240910/202409100717.2rKMS0oi-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409100717.2rKMS0oi-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/iio/light/ltr390.c:633:19: error: call to undeclared function 'irq_get_trigger_type'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration]
     633 |                 int irq_flags = irq_get_trigger_type(client->irq);
         |                                 ^
   1 error generated.


vim +/irq_get_trigger_type +633 drivers/iio/light/ltr390.c

   578	
   579	static int ltr390_probe(struct i2c_client *client)
   580	{
   581		struct ltr390_data *data;
   582		struct iio_dev *indio_dev;
   583		struct device *dev;
   584		int ret, part_number;
   585	
   586		dev = &client->dev;
   587		indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
   588		if (!indio_dev)
   589			return -ENOMEM;
   590	
   591		data = iio_priv(indio_dev);
   592	
   593		data->regmap = devm_regmap_init_i2c(client, &ltr390_regmap_config);
   594		if (IS_ERR(data->regmap))
   595			return dev_err_probe(dev, PTR_ERR(data->regmap),
   596					     "regmap initialization failed\n");
   597	
   598		data->client = client;
   599		/* default value of integration time from pg: 15 of the datasheet */
   600		data->int_time_us = 100000;
   601		/* default value of gain from pg: 16 of the datasheet */
   602		data->gain = 3;
   603		/* default mode for ltr390 is ALS mode */
   604		data->mode = LTR390_SET_ALS_MODE;
   605	
   606		mutex_init(&data->lock);
   607	
   608		indio_dev->info = &ltr390_info;
   609		indio_dev->channels = ltr390_channels;
   610		indio_dev->num_channels = ARRAY_SIZE(ltr390_channels);
   611		indio_dev->name = "ltr390";
   612	
   613		ret = regmap_read(data->regmap, LTR390_PART_ID, &part_number);
   614		if (ret)
   615			return dev_err_probe(dev, ret,
   616					     "failed to get sensor's part id\n");
   617		/* Lower 4 bits of `part_number` change with hardware revisions */
   618		if (part_number >> 4 != LTR390_PART_NUMBER_ID)
   619			dev_info(dev, "received invalid product id: 0x%x", part_number);
   620		dev_dbg(dev, "LTR390, product id: 0x%x\n", part_number);
   621	
   622		/* reset sensor, chip fails to respond to this, so ignore any errors */
   623		regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SW_RESET);
   624	
   625		/* Wait for the registers to reset before proceeding */
   626		usleep_range(1000, 2000);
   627	
   628		ret = regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
   629		if (ret)
   630			return dev_err_probe(dev, ret, "failed to enable the sensor\n");
   631	
   632		if (client->irq) {
 > 633			int irq_flags = irq_get_trigger_type(client->irq);
   634	
   635			if (!irq_flags)
   636				irq_flags = IRQF_TRIGGER_FALLING;
   637	
   638			ret = devm_request_threaded_irq(&client->dev, client->irq,
   639							NULL, ltr390_interrupt_handler,
   640							irq_flags | IRQF_ONESHOT,
   641							"ltr390_thresh_event", indio_dev);
   642			if (ret) {
   643				dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
   644				return ret;
   645			}
   646		}
   647	
   648		return devm_iio_device_register(dev, indio_dev);
   649	}
   650	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH 3/4] iio: light: ltr390: Interrupts and threshold event support

[kernel test robot]

Hi Abhash,

kernel test robot noticed the following build errors:

[auto build test ERROR on jic23-iio/togreg]
[also build test ERROR on next-20240909]
[cannot apply to linus/master v6.11-rc7]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Abhash-Jha/iio-light-ltr390-Suspend-and-Resume-support/20240909-193623
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/20240909103623.264113-4-abhashkumarjha123%40gmail.com
patch subject: [PATCH 3/4] iio: light: ltr390: Interrupts and threshold event support
config: i386-buildonly-randconfig-002-20240910 (https://download.01.org/0day-ci/archive/20240910/202409101339.74gDdc6n-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240910/202409101339.74gDdc6n-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202409101339.74gDdc6n-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/iio/light/ltr390.c: In function 'ltr390_probe':
>> drivers/iio/light/ltr390.c:633:33: error: implicit declaration of function 'irq_get_trigger_type' [-Werror=implicit-function-declaration]
     633 |                 int irq_flags = irq_get_trigger_type(client->irq);
         |                                 ^~~~~~~~~~~~~~~~~~~~
   cc1: some warnings being treated as errors


vim +/irq_get_trigger_type +633 drivers/iio/light/ltr390.c

   578	
   579	static int ltr390_probe(struct i2c_client *client)
   580	{
   581		struct ltr390_data *data;
   582		struct iio_dev *indio_dev;
   583		struct device *dev;
   584		int ret, part_number;
   585	
   586		dev = &client->dev;
   587		indio_dev = devm_iio_device_alloc(dev, sizeof(*data));
   588		if (!indio_dev)
   589			return -ENOMEM;
   590	
   591		data = iio_priv(indio_dev);
   592	
   593		data->regmap = devm_regmap_init_i2c(client, &ltr390_regmap_config);
   594		if (IS_ERR(data->regmap))
   595			return dev_err_probe(dev, PTR_ERR(data->regmap),
   596					     "regmap initialization failed\n");
   597	
   598		data->client = client;
   599		/* default value of integration time from pg: 15 of the datasheet */
   600		data->int_time_us = 100000;
   601		/* default value of gain from pg: 16 of the datasheet */
   602		data->gain = 3;
   603		/* default mode for ltr390 is ALS mode */
   604		data->mode = LTR390_SET_ALS_MODE;
   605	
   606		mutex_init(&data->lock);
   607	
   608		indio_dev->info = &ltr390_info;
   609		indio_dev->channels = ltr390_channels;
   610		indio_dev->num_channels = ARRAY_SIZE(ltr390_channels);
   611		indio_dev->name = "ltr390";
   612	
   613		ret = regmap_read(data->regmap, LTR390_PART_ID, &part_number);
   614		if (ret)
   615			return dev_err_probe(dev, ret,
   616					     "failed to get sensor's part id\n");
   617		/* Lower 4 bits of `part_number` change with hardware revisions */
   618		if (part_number >> 4 != LTR390_PART_NUMBER_ID)
   619			dev_info(dev, "received invalid product id: 0x%x", part_number);
   620		dev_dbg(dev, "LTR390, product id: 0x%x\n", part_number);
   621	
   622		/* reset sensor, chip fails to respond to this, so ignore any errors */
   623		regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SW_RESET);
   624	
   625		/* Wait for the registers to reset before proceeding */
   626		usleep_range(1000, 2000);
   627	
   628		ret = regmap_set_bits(data->regmap, LTR390_MAIN_CTRL, LTR390_SENSOR_ENABLE);
   629		if (ret)
   630			return dev_err_probe(dev, ret, "failed to enable the sensor\n");
   631	
   632		if (client->irq) {
 > 633			int irq_flags = irq_get_trigger_type(client->irq);
   634	
   635			if (!irq_flags)
   636				irq_flags = IRQF_TRIGGER_FALLING;
   637	
   638			ret = devm_request_threaded_irq(&client->dev, client->irq,
   639							NULL, ltr390_interrupt_handler,
   640							irq_flags | IRQF_ONESHOT,
   641							"ltr390_thresh_event", indio_dev);
   642			if (ret) {
   643				dev_err(&client->dev, "request irq (%d) failed\n", client->irq);
   644				return ret;
   645			}
   646		}
   647	
   648		return devm_iio_device_register(dev, indio_dev);
   649	}
   650	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki