Added LTR501 Interrupt support

Added regmap support. It will be useful to handle
bitwise updates to als & ps control registers.

Signed-off-by Kuppuswamy Sathyanarayanan <[email protected]>

Signed-off-by Jonathan Cameron <[email protected]>

---
 drivers/iio/light/ltr501.c | 129 ++++++++++++++++++++++++++++++---------------
 1 file changed, 86 insertions(+), 43 deletions(-)

drivers/iio/light/ltr501.c +86 -43

index f208c98..e2f7354 100644
@@ -16,6 +16,7 @@
 #include <linux/i2c.h>
 #include <linux/err.h>
 #include <linux/delay.h>
+#include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>

@@ -33,6 +34,7 @@
 #define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
 #define LTR501_ALS_PS_STATUS 0x8c
 #define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
+#define LTR501_MAX_REG 0x9f
 
 #define LTR501_ALS_CONTR_SW_RESET BIT(2)
 #define LTR501_CONTR_PS_GAIN_MASK (BIT(3) | BIT(2))

@@ -45,23 +47,25 @@
 
 #define LTR501_PS_DATA_MASK 0x7ff
 
+#define LTR501_REGMAP_NAME "ltr501_regmap"
+
 struct ltr501_data {
 	struct i2c_client *client;
 	struct mutex lock_als, lock_ps;
 	u8 als_contr, ps_contr;
+	struct regmap *regmap;
 };
 
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 {
 	int tries = 100;
-	int ret;
+	int ret, status;
 
 	while (tries--) {
-		ret = i2c_smbus_read_byte_data(data->client,
-					       LTR501_ALS_PS_STATUS);
+		ret = regmap_read(data->regmap, LTR501_ALS_PS_STATUS, &status);
 		if (ret < 0)
 			return ret;
-		if ((ret & drdy_mask) == drdy_mask)
+		if ((status & drdy_mask) == drdy_mask)
 			return 0;
 		msleep(25);
 	}

@@ -72,21 +76,30 @@ static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 
 static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
 {
-	int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
+	int ret;
+
+	ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);
 	if (ret < 0)
 		return ret;
 	/* always read both ALS channels in given order */
-	return i2c_smbus_read_i2c_block_data(data->client,
-					     LTR501_ALS_DATA1,
-					     2 * sizeof(__le16), (u8 *)buf);
+	return regmap_bulk_read(data->regmap, LTR501_ALS_DATA1,
+				buf, 2 * sizeof(__le16));
 }
 
 static int ltr501_read_ps(struct ltr501_data *data)
 {
-	int ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
+	int ret, status;
+
+	ret = ltr501_drdy(data, LTR501_STATUS_PS_RDY);
+	if (ret < 0)
+		return ret;
+
+	ret = regmap_bulk_read(data->regmap, LTR501_PS_DATA,
+			       &status, 2);
 	if (ret < 0)
 		return ret;
-	return i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
+
+	return status;
 }
 
 #define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \

@@ -170,11 +183,10 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
 				*val = 0;
 				*val2 = 5000;
 				return IIO_VAL_INT_PLUS_MICRO;
-			} else {
-				*val = 1;
-				*val2 = 0;
-				return IIO_VAL_INT;
 			}
+			*val = 1;
+			*val2 = 0;
+			return IIO_VAL_INT;
 		case IIO_PROXIMITY:
 			i = (data->ps_contr & LTR501_CONTR_PS_GAIN_MASK) >>
 				LTR501_CONTR_PS_GAIN_SHIFT;

@@ -219,18 +231,18 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 				data->als_contr &= ~LTR501_CONTR_ALS_GAIN_MASK;
 			else
 				return -EINVAL;
-			return i2c_smbus_write_byte_data(data->client,
-							 LTR501_ALS_CONTR,
-							 data->als_contr);
+
+			return regmap_write(data->regmap, LTR501_ALS_CONTR,
+					    data->als_contr);
 		case IIO_PROXIMITY:
 			i = ltr501_get_ps_gain_index(val, val2);
 			if (i < 0)
 				return -EINVAL;
 			data->ps_contr &= ~LTR501_CONTR_PS_GAIN_MASK;
 			data->ps_contr |= i << LTR501_CONTR_PS_GAIN_SHIFT;
-			return i2c_smbus_write_byte_data(data->client,
-							 LTR501_PS_CONTR,
-							 data->ps_contr);
+
+			return regmap_write(data->regmap, LTR501_PS_CONTR,
+					    data->ps_contr);
 		default:
 			return -EINVAL;
 		}

@@ -258,13 +270,15 @@ static const struct iio_info ltr501_info = {
 	.driver_module = THIS_MODULE,
 };
 
-static int ltr501_write_contr(struct i2c_client *client, u8 als_val, u8 ps_val)
+static int ltr501_write_contr(struct ltr501_data *data, u8 als_val, u8 ps_val)
 {
-	int ret = i2c_smbus_write_byte_data(client, LTR501_ALS_CONTR, als_val);
+	int ret;
+
+	ret = regmap_write(data->regmap, LTR501_ALS_CONTR, als_val);
 	if (ret < 0)
 		return ret;
 
-	return i2c_smbus_write_byte_data(client, LTR501_PS_CONTR, ps_val);
+	return regmap_write(data->regmap, LTR501_PS_CONTR, ps_val);
 }
 
 static irqreturn_t ltr501_trigger_handler(int irq, void *p)

@@ -276,7 +290,7 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 	__le16 als_buf[2];
 	u8 mask = 0;
 	int j = 0;
-	int ret;
+	int ret, psdata;
 
 	memset(buf, 0, sizeof(buf));
 

@@ -292,10 +306,8 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 		goto done;
 
 	if (mask & LTR501_STATUS_ALS_RDY) {
-		ret = i2c_smbus_read_i2c_block_data(data->client,
-						    LTR501_ALS_DATA1,
-						    sizeof(als_buf),
-						    (u8 *)als_buf);
+		ret = regmap_bulk_read(data->regmap, LTR501_ALS_DATA1,
+				       (u8 *)als_buf, sizeof(als_buf));
 		if (ret < 0)
 			return ret;
 		if (test_bit(0, indio_dev->active_scan_mask))

@@ -305,10 +317,11 @@ static irqreturn_t ltr501_trigger_handler(int irq, void *p)
 	}
 
 	if (mask & LTR501_STATUS_PS_RDY) {
-		ret = i2c_smbus_read_word_data(data->client, LTR501_PS_DATA);
+		ret = regmap_bulk_read(data->regmap, LTR501_PS_DATA,
+				       &psdata, 2);
 		if (ret < 0)
 			goto done;
-		buf[j++] = ret & LTR501_PS_DATA_MASK;
+		buf[j++] = psdata & LTR501_PS_DATA_MASK;
 	}
 
 	iio_push_to_buffers_with_timestamp(indio_dev, buf, iio_get_time_ns());

@@ -321,26 +334,48 @@ done:
 
 static int ltr501_init(struct ltr501_data *data)
 {
-	int ret;
+	int ret, status;
 
-	ret = i2c_smbus_read_byte_data(data->client, LTR501_ALS_CONTR);
+	ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);
 	if (ret < 0)
 		return ret;
-	data->als_contr = ret | LTR501_CONTR_ACTIVE;
 
-	ret = i2c_smbus_read_byte_data(data->client, LTR501_PS_CONTR);
+	data->als_contr = status | LTR501_CONTR_ACTIVE;
+
+	ret = regmap_read(data->regmap, LTR501_PS_CONTR, &status);
 	if (ret < 0)
 		return ret;
-	data->ps_contr = ret | LTR501_CONTR_ACTIVE;
 
-	return ltr501_write_contr(data->client, data->als_contr,
-				  data->ps_contr);
+	data->ps_contr = status | LTR501_CONTR_ACTIVE;
+
+	return ltr501_write_contr(data, data->als_contr, data->ps_contr);
 }
 
+static bool ltr501_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case LTR501_ALS_DATA1:
+	case LTR501_ALS_DATA0:
+	case LTR501_ALS_PS_STATUS:
+	case LTR501_PS_DATA:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static struct regmap_config ltr501_regmap_config = {
+	.name =  LTR501_REGMAP_NAME,
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = LTR501_MAX_REG,
+	.cache_type = REGCACHE_RBTREE,
+	.volatile_reg = ltr501_is_volatile_reg,
+};
+
 static int ltr501_powerdown(struct ltr501_data *data)
 {
-	return ltr501_write_contr(data->client,
-				  data->als_contr & ~LTR501_CONTR_ACTIVE,
+	return ltr501_write_contr(data, data->als_contr & ~LTR501_CONTR_ACTIVE,
 				  data->ps_contr & ~LTR501_CONTR_ACTIVE);
 }
 

@@ -349,22 +384,30 @@ static int ltr501_probe(struct i2c_client *client,
 {
 	struct ltr501_data *data;
 	struct iio_dev *indio_dev;
-	int ret;
+	struct regmap *regmap;
+	int ret, partid;
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (!indio_dev)
 		return -ENOMEM;
 
+	regmap = devm_regmap_init_i2c(client, &ltr501_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "Regmap initialization failed.\n");
+		return PTR_ERR(regmap);
+	}
+
 	data = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	data->client = client;
+	data->regmap = regmap;
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);
 
-	ret = i2c_smbus_read_byte_data(data->client, LTR501_PART_ID);
+	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
 	if (ret < 0)
 		return ret;
-	if ((ret >> 4) != 0x8)
+	if ((partid >> 4) != 0x8)
 		return -ENODEV;
 
 	indio_dev->dev.parent = &client->dev;

@@ -420,7 +463,7 @@ static int ltr501_resume(struct device *dev)
 	struct ltr501_data *data = iio_priv(i2c_get_clientdata(
 					    to_i2c_client(dev)));
 
-	return ltr501_write_contr(data->client, data->als_contr,
+	return ltr501_write_contr(data, data->als_contr,
 		data->ps_contr);
 }
 #endif

Added support to modify and read ALS integration time.

Signed-off-by Kuppuswamy Sathyanarayanan <[email protected]>

---
 drivers/iio/light/ltr501.c | 90 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 89 insertions(+), 1 deletion(-)

drivers/iio/light/ltr501.c +89 -1

index e2f7354..8092604 100644
@@ -28,6 +28,7 @@
 
 #define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
 #define LTR501_PS_CONTR 0x81 /* PS operation mode */
+#define LTR501_ALS_MEAS_RATE 0x85 /* ALS integ time, measurement rate*/
 #define LTR501_PART_ID 0x86
 #define LTR501_MANUFAC_ID 0x87
 #define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */

@@ -49,11 +50,17 @@
 
 #define LTR501_REGMAP_NAME "ltr501_regmap"
 
+static const int int_time_mapping[] = {100000, 50000, 200000, 400000};
+
+static const struct reg_field reg_field_it =
+				REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
+
 struct ltr501_data {
 	struct i2c_client *client;
 	struct mutex lock_als, lock_ps;
 	u8 als_contr, ps_contr;
 	struct regmap *regmap;
+	struct regmap_field *reg_it;
 };
 
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)

@@ -74,6 +81,58 @@ static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 	return -EIO;
 }
 
+static int ltr501_set_it_time(struct ltr501_data *data, int it)
+{
+	int ret, i, index = -1, status;
+
+	for (i = 0; i < ARRAY_SIZE(int_time_mapping); i++) {
+		if (int_time_mapping[i] == it) {
+			index = i;
+			break;
+		}
+	}
+	/* Make sure integ time index is valid */
+	if (index < 0)
+		return -EINVAL;
+
+	ret = regmap_read(data->regmap, LTR501_ALS_CONTR, &status);
+	if (ret < 0)
+		return ret;
+
+	if (status & LTR501_CONTR_ALS_GAIN_MASK) {
+		/*
+		 * 200 ms and 400 ms integ time can only be
+		 * used in dynamic range 1
+		 */
+		if (index > 1)
+			return -EINVAL;
+	} else
+		/* 50 ms integ time can only be used in dynamic range 2 */
+		if (index == 1)
+			return -EINVAL;
+
+	return regmap_field_write(data->reg_it, index);
+}
+
+/* read int time in micro seconds */
+static int ltr501_read_it_time(struct ltr501_data *data, int *val, int *val2)
+{
+	int ret, index;
+
+	ret = regmap_field_read(data->reg_it, &index);
+	if (ret < 0)
+		return ret;
+
+	/* Make sure integ time index is valid */
+	if (index < 0 || index >= ARRAY_SIZE(int_time_mapping))
+		return -EINVAL;
+
+	*val2 = int_time_mapping[index];
+	*val = 0;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
 static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
 {
 	int ret;

@@ -121,7 +180,8 @@ static int ltr501_read_ps(struct ltr501_data *data)
 static const struct iio_chan_spec ltr501_channels[] = {
 	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
 	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
-				 BIT(IIO_CHAN_INFO_SCALE)),
+				 BIT(IIO_CHAN_INFO_SCALE) |
+				 BIT(IIO_CHAN_INFO_INT_TIME)),
 	{
 		.type = IIO_PROXIMITY,
 		.address = LTR501_PS_DATA,

@@ -196,6 +256,13 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_INT_TIME:
+		switch (chan->type) {
+		case IIO_INTENSITY:
+			return ltr501_read_it_time(data, val, val2);
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }

@@ -246,16 +313,30 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_INT_TIME:
+		switch (chan->type) {
+		case IIO_INTENSITY:
+			if (val != 0)
+				return -EINVAL;
+			mutex_lock(&data->lock_als);
+			i = ltr501_set_it_time(data, val2);
+			mutex_unlock(&data->lock_als);
+			return i;
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }
 
 static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
 static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
+static IIO_CONST_ATTR_INT_TIME_AVAIL("0.05 0.1 0.2 0.4");
 
 static struct attribute *ltr501_attributes[] = {
 	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
 	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
+	&iio_const_attr_integration_time_available.dev_attr.attr,
 	NULL
 };
 

@@ -404,6 +485,13 @@ static int ltr501_probe(struct i2c_client *client,
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);
 
+	data->reg_it = devm_regmap_field_alloc(&client->dev, regmap,
+					       reg_field_it);
+	if (IS_ERR(data->reg_it)) {
+		dev_err(&client->dev, "Integ time reg field init failed.\n");
+		return PTR_ERR(data->reg_it);
+	}
+
 	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
 	if (ret < 0)
 		return ret;

Added support to modify and read ALS integration time.

Signed-off-by Kuppuswamy Sathyanarayanan <[email protected]>

---
 drivers/iio/light/ltr501.c | 90 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 89 insertions(+), 1 deletion(-)

drivers/iio/light/ltr501.c +1 -0

index e2f7354..8092604 100644
@@ -28,6 +28,7 @@
 
 #define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
 #define LTR501_PS_CONTR 0x81 /* PS operation mode */
+#define LTR501_ALS_MEAS_RATE 0x85 /* ALS integ time, measurement rate*/
 #define LTR501_PART_ID 0x86
 #define LTR501_MANUFAC_ID 0x87
 #define LTR501_ALS_DATA1 0x88 /* 16-bit, little endian */

drivers/iio/light/ltr501.c +14 -0

+
+static const struct reg_field reg_field_it =
+				REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
+
 struct ltr501_data {
 	struct i2c_client *client;
 	struct mutex lock_als, lock_ps;
 	u8 als_contr, ps_contr;
 	struct regmap *regmap;
+	struct regmap_field *reg_it;
 };
 
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)

@@ -74,6 +81,58 @@ static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 	return -EIO;
 }
 
+static int ltr501_set_it_time(struct ltr501_data *data, int it)
+{
+	int ret, i, index = -1, status;
+
+	for (i = 0; i < ARRAY_SIZE(int_time_mapping); i++) {
+		if (int_time_mapping[i] == it) {
+			index = i;
+			break;
+		}

drivers/iio/light/ltr501.c +56 -1

+		/* 50 ms integ time can only be used in dynamic range 2 */
+		if (index == 1)
+			return -EINVAL;
+
+	return regmap_field_write(data->reg_it, index);
+}
+
+/* read int time in micro seconds */
+static int ltr501_read_it_time(struct ltr501_data *data, int *val, int *val2)
+{
+	int ret, index;
+
+	ret = regmap_field_read(data->reg_it, &index);
+	if (ret < 0)
+		return ret;
+
+	/* Make sure integ time index is valid */
+	if (index < 0 || index >= ARRAY_SIZE(int_time_mapping))
+		return -EINVAL;
+
+	*val2 = int_time_mapping[index];
+	*val = 0;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
 static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
 {
 	int ret;

@@ -121,7 +180,8 @@ static int ltr501_read_ps(struct ltr501_data *data)
 static const struct iio_chan_spec ltr501_channels[] = {
 	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
 	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
-				 BIT(IIO_CHAN_INFO_SCALE)),
+				 BIT(IIO_CHAN_INFO_SCALE) |
+				 BIT(IIO_CHAN_INFO_INT_TIME)),
 	{
 		.type = IIO_PROXIMITY,
 		.address = LTR501_PS_DATA,

@@ -196,6 +256,13 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_INT_TIME:
+		switch (chan->type) {
+		case IIO_INTENSITY:
+			return ltr501_read_it_time(data, val, val2);
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }

@@ -246,16 +313,30 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_INT_TIME:
+		switch (chan->type) {
+		case IIO_INTENSITY:
+			if (val != 0)
+				return -EINVAL;
+			mutex_lock(&data->lock_als);
+			i = ltr501_set_it_time(data, val2);
+			mutex_unlock(&data->lock_als);
+			return i;
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }
 
 static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
 static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
+static IIO_CONST_ATTR_INT_TIME_AVAIL("0.05 0.1 0.2 0.4");
 
 static struct attribute *ltr501_attributes[] = {
 	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
 	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
+	&iio_const_attr_integration_time_available.dev_attr.attr,
 	NULL
 };
 

@@ -404,6 +485,13 @@ static int ltr501_probe(struct i2c_client *client,
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);
 
+	data->reg_it = devm_regmap_field_alloc(&client->dev, regmap,
+					       reg_field_it);
+	if (IS_ERR(data->reg_it)) {
+		dev_err(&client->dev, "Integ time reg field init failed.\n");
+		return PTR_ERR(data->reg_it);
+	}
+
 	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
 	if (ret < 0)
 		return ret;

This patch adds interrupt support for Liteon 501 chip.

Interrupt will be generated whenever ALS or proximity data exceeds values given in upper and lower threshold register settings.

Signed-off-by Kuppuswamy Sathyanarayanan <[email protected]>

---
 drivers/iio/light/ltr501.c | 319 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 313 insertions(+), 6 deletions(-)

drivers/iio/light/ltr501.c +313 -6

index 8092604..593dbb1 100644
@@ -9,7 +9,7 @@
  *
  * 7-bit I2C slave address 0x23
  *
- * TODO: interrupt, threshold, measurement rate, IR LED characteristics
+ * TODO: measurement rate, IR LED characteristics
  */
 
 #include <linux/module.h>

@@ -19,6 +19,7 @@
 #include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/events.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/buffer.h>

@@ -35,6 +36,11 @@
 #define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
 #define LTR501_ALS_PS_STATUS 0x8c
 #define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
+#define LTR501_INTR 0x8f /* output mode, polarity, mode */
+#define LTR501_PS_THRESH_UP 0x90 /* 11 bit, ps upper threshold */
+#define LTR501_PS_THRESH_LOW 0x92 /* 11 bit, ps lower threshold */
+#define LTR501_ALS_THRESH_UP 0x97 /* 16 bit, ALS upper threshold */
+#define LTR501_ALS_THRESH_LOW 0x99 /* 16 bit, ALS lower threshold */
 #define LTR501_MAX_REG 0x9f
 
 #define LTR501_ALS_CONTR_SW_RESET BIT(2)

@@ -43,10 +49,14 @@
 #define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
 #define LTR501_CONTR_ACTIVE BIT(1)
 
+#define LTR501_STATUS_ALS_INTR BIT(3)
 #define LTR501_STATUS_ALS_RDY BIT(2)
+#define LTR501_STATUS_PS_INTR BIT(1)
 #define LTR501_STATUS_PS_RDY BIT(0)
 
 #define LTR501_PS_DATA_MASK 0x7ff
+#define LTR501_PS_THRESH_MASK 0x7ff
+#define LTR501_ALS_THRESH_MASK 0xffff
 
 #define LTR501_REGMAP_NAME "ltr501_regmap"
 

@@ -54,6 +64,10 @@ static const int int_time_mapping[] = {100000, 50000, 200000, 400000};
 
 static const struct reg_field reg_field_it =
 				REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
+static const struct reg_field reg_field_als_intr =
+				REG_FIELD(LTR501_INTR, 0, 0);
+static const struct reg_field reg_field_ps_intr =
+				REG_FIELD(LTR501_INTR, 1, 1);
 
 struct ltr501_data {
 	struct i2c_client *client;

@@ -61,6 +75,8 @@ struct ltr501_data {
 	u8 als_contr, ps_contr;
 	struct regmap *regmap;
 	struct regmap_field *reg_it;
+	struct regmap_field *reg_als_intr;
+	struct regmap_field *reg_ps_intr;
 };
 
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)

@@ -161,7 +177,41 @@ static int ltr501_read_ps(struct ltr501_data *data)
 	return status;
 }
 
-#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
+static const struct iio_event_spec ltr501_als_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_event_spec ltr501_pxs_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),
+	},
+};
+
+#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared, \
+				 _evspec, _evsize) { \
 	.type = IIO_INTENSITY, \
 	.modified = 1, \
 	.address = (_addr), \

@@ -174,14 +224,19 @@ static int ltr501_read_ps(struct ltr501_data *data)
 		.realbits = 16, \
 		.storagebits = 16, \
 		.endianness = IIO_CPU, \
-	} \
+	}, \
+	.event_spec = _evspec,\
+	.num_event_specs = _evsize,\
 }
 
 static const struct iio_chan_spec ltr501_channels[] = {
-	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
+	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0,
+				 ltr501_als_event_spec,
+				 ARRAY_SIZE(ltr501_als_event_spec)),
 	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
 				 BIT(IIO_CHAN_INFO_SCALE) |
-				 BIT(IIO_CHAN_INFO_INT_TIME)),
+				 BIT(IIO_CHAN_INFO_INT_TIME),
+				 NULL, 0),
 	{
 		.type = IIO_PROXIMITY,
 		.address = LTR501_PS_DATA,

@@ -194,6 +249,8 @@ static const struct iio_chan_spec ltr501_channels[] = {
 			.storagebits = 16,
 			.endianness = IIO_CPU,
 		},
+		.event_spec = ltr501_pxs_event_spec,
+		.num_event_specs = ARRAY_SIZE(ltr501_pxs_event_spec),
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };

@@ -329,6 +386,185 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 	return -EINVAL;
 }
 
+static int ltr501_read_thresh(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)
+{
+	struct ltr501_data *data = iio_priv(indio_dev);
+	int ret, thresh_data;
+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_ALS_THRESH_UP,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_ALS_THRESH_MASK;
+			return IIO_VAL_INT;
+		case IIO_EV_DIR_FALLING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_ALS_THRESH_LOW,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_ALS_THRESH_MASK;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_PROXIMITY:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_PS_THRESH_UP,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_PS_THRESH_MASK;
+			return IIO_VAL_INT;
+		case IIO_EV_DIR_FALLING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_PS_THRESH_LOW,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_PS_THRESH_MASK;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_write_thresh(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)
+{
+	struct ltr501_data *data = iio_priv(indio_dev);
+	int ret;
+
+	if (val < 0)
+		return -EINVAL;
+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		if (val > LTR501_ALS_THRESH_MASK)
+			return -EINVAL;
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			mutex_lock(&data->lock_als);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_ALS_THRESH_UP,
+						&val, 2);
+			mutex_unlock(&data->lock_als);
+			return ret;
+		case IIO_EV_DIR_FALLING:
+			mutex_lock(&data->lock_als);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_ALS_THRESH_LOW,
+						&val, 2);
+			mutex_unlock(&data->lock_als);
+			return ret;
+		default:
+			return -EINVAL;
+		}
+	case IIO_PROXIMITY:
+		switch (dir) {
+		if (val > LTR501_PS_THRESH_MASK)
+			return -EINVAL;
+		case IIO_EV_DIR_RISING:
+			mutex_lock(&data->lock_ps);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_PS_THRESH_UP,
+						&val, 2);
+			mutex_unlock(&data->lock_ps);
+			return ret;
+		case IIO_EV_DIR_FALLING:
+			mutex_lock(&data->lock_ps);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_PS_THRESH_LOW,
+						&val, 2);
+			mutex_unlock(&data->lock_ps);
+			return ret;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_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 ltr501_data *data = iio_priv(indio_dev);
+	int ret, status;
+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		ret = regmap_field_read(data->reg_als_intr, &status);
+		if (ret < 0)
+			return ret;
+		return status;
+	case IIO_PROXIMITY:
+		ret = regmap_field_read(data->reg_ps_intr, &status);
+		if (ret < 0)
+			return ret;
+		return status;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_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 ltr501_data *data = iio_priv(indio_dev);
+	int ret;
+
+	/* only 1 and 0 are valid inputs */
+	if (state != 1  || state != 0)
+		return -EINVAL;
+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		mutex_lock(&data->lock_als);
+		ret = regmap_field_write(data->reg_als_intr, state);
+		mutex_unlock(&data->lock_als);
+		return ret;
+	case IIO_PROXIMITY:
+		mutex_lock(&data->lock_ps);
+		ret = regmap_field_write(data->reg_ps_intr, state);
+		mutex_unlock(&data->lock_ps);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
 static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
 static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.05 0.1 0.2 0.4");

@@ -344,10 +580,21 @@ static const struct attribute_group ltr501_attribute_group = {
 	.attrs = ltr501_attributes,
 };
 
+static const struct iio_info ltr501_info_no_irq = {
+	.read_raw = ltr501_read_raw,
+	.write_raw = ltr501_write_raw,
+	.attrs = &ltr501_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
 static const struct iio_info ltr501_info = {
 	.read_raw = ltr501_read_raw,
 	.write_raw = ltr501_write_raw,
 	.attrs = &ltr501_attribute_group,
+	.read_event_value	= &ltr501_read_thresh,
+	.write_event_value	= &ltr501_write_thresh,
+	.read_event_config	= &ltr501_read_event_config,
+	.write_event_config	= &ltr501_write_event_config,
 	.driver_module = THIS_MODULE,
 };
 

@@ -413,6 +660,36 @@ done:
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t ltr501_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct ltr501_data *data = iio_priv(indio_dev);
+	int ret, status;
+
+	ret = regmap_read(data->regmap, LTR501_ALS_PS_STATUS, &status);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"irq read int reg failed\n");
+		return IRQ_HANDLED;
+	}
+
+	if (status & LTR501_STATUS_ALS_INTR)
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
+						    IIO_EV_TYPE_THRESH,
+						    IIO_EV_DIR_EITHER),
+			       iio_get_time_ns());
+
+	if (status & LTR501_STATUS_PS_INTR)
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+						    IIO_EV_TYPE_THRESH,
+						    IIO_EV_DIR_EITHER),
+			       iio_get_time_ns());
+
+	return IRQ_HANDLED;
+}
+
 static int ltr501_init(struct ltr501_data *data)
 {
 	int ret, status;

@@ -492,6 +769,20 @@ static int ltr501_probe(struct i2c_client *client,
 		return PTR_ERR(data->reg_it);
 	}
 
+	data->reg_als_intr = devm_regmap_field_alloc(&client->dev, regmap,
+						     reg_field_als_intr);
+	if (IS_ERR(data->reg_als_intr)) {
+		dev_err(&client->dev, "ALS intr mode reg field init failed\n");
+		return PTR_ERR(data->reg_als_intr);
+	}
+
+	data->reg_ps_intr = devm_regmap_field_alloc(&client->dev, regmap,
+						    reg_field_ps_intr);
+	if (IS_ERR(data->reg_ps_intr)) {
+		dev_err(&client->dev, "PS intr mode reg field init failed.\n");
+		return PTR_ERR(data->reg_ps_intr);
+	}
+
 	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
 	if (ret < 0)
 		return ret;

@@ -499,7 +790,6 @@ static int ltr501_probe(struct i2c_client *client,
 		return -ENODEV;
 
 	indio_dev->dev.parent = &client->dev;
-	indio_dev->info = &ltr501_info;
 	indio_dev->channels = ltr501_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
 	indio_dev->name = LTR501_DRV_NAME;

@@ -509,6 +799,23 @@ static int ltr501_probe(struct i2c_client *client,
 	if (ret < 0)
 		return ret;
 
+	if (client->irq > 0) {
+		indio_dev->info = &ltr501_info;
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, ltr501_interrupt_handler,
+						IRQF_TRIGGER_FALLING |
+						IRQF_ONESHOT,
+						"ltr501_thresh_event",
+						indio_dev);
+		if (ret) {
+			dev_err(&client->dev, "request irq (%d) failed\n",
+				client->irq);
+			return ret;
+		}
+	} else {
+		indio_dev->info = &ltr501_info_no_irq;
+	}
+
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 					 ltr501_trigger_handler, NULL);
 	if (ret)

This patch adds interrupt support for Liteon 501 chip.

Interrupt will be generated whenever ALS or proximity data exceeds values given in upper and lower threshold register settings.

Signed-off-by Kuppuswamy Sathyanarayanan <[email protected]>

---
 drivers/iio/light/ltr501.c | 319 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 313 insertions(+), 6 deletions(-)

drivers/iio/light/ltr501.c +11 -1

index 8092604..593dbb1 100644
@@ -9,7 +9,7 @@
  *
  * 7-bit I2C slave address 0x23
  *
- * TODO: interrupt, threshold, measurement rate, IR LED characteristics
+ * TODO: measurement rate, IR LED characteristics
  */
 
 #include <linux/module.h>

@@ -19,6 +19,7 @@
 #include <linux/regmap.h>
 
 #include <linux/iio/iio.h>
+#include <linux/iio/events.h>
 #include <linux/iio/sysfs.h>
 #include <linux/iio/trigger_consumer.h>
 #include <linux/iio/buffer.h>

@@ -35,6 +36,11 @@
 #define LTR501_ALS_DATA0 0x8a /* 16-bit, little endian */
 #define LTR501_ALS_PS_STATUS 0x8c
 #define LTR501_PS_DATA 0x8d /* 16-bit, little endian */
+#define LTR501_INTR 0x8f /* output mode, polarity, mode */
+#define LTR501_PS_THRESH_UP 0x90 /* 11 bit, ps upper threshold */
+#define LTR501_PS_THRESH_LOW 0x92 /* 11 bit, ps lower threshold */
+#define LTR501_ALS_THRESH_UP 0x97 /* 16 bit, ALS upper threshold */
+#define LTR501_ALS_THRESH_LOW 0x99 /* 16 bit, ALS lower threshold */
 #define LTR501_MAX_REG 0x9f
 
 #define LTR501_ALS_CONTR_SW_RESET BIT(2)

@@ -43,10 +49,14 @@
 #define LTR501_CONTR_ALS_GAIN_MASK BIT(3)
 #define LTR501_CONTR_ACTIVE BIT(1)
 
+#define LTR501_STATUS_ALS_INTR BIT(3)
 #define LTR501_STATUS_ALS_RDY BIT(2)
+#define LTR501_STATUS_PS_INTR BIT(1)
 #define LTR501_STATUS_PS_RDY BIT(0)
 
 #define LTR501_PS_DATA_MASK 0x7ff
+#define LTR501_PS_THRESH_MASK 0x7ff
+#define LTR501_ALS_THRESH_MASK 0xffff
 
 #define LTR501_REGMAP_NAME "ltr501_regmap"
 

drivers/iio/light/ltr501.c +47 -4

 struct ltr501_data {
 	struct i2c_client *client;

@@ -61,6 +75,8 @@ struct ltr501_data {
 	u8 als_contr, ps_contr;
 	struct regmap *regmap;
 	struct regmap_field *reg_it;
+	struct regmap_field *reg_als_intr;
+	struct regmap_field *reg_ps_intr;
 };
 
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)

@@ -161,7 +177,41 @@ static int ltr501_read_ps(struct ltr501_data *data)
 	return status;
 }
 
-#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared) { \
+static const struct iio_event_spec ltr501_als_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_event_spec ltr501_pxs_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),
+	},
+};
+
+#define LTR501_INTENSITY_CHANNEL(_idx, _addr, _mod, _shared, \
+				 _evspec, _evsize) { \
 	.type = IIO_INTENSITY, \
 	.modified = 1, \
 	.address = (_addr), \

@@ -174,14 +224,19 @@ static int ltr501_read_ps(struct ltr501_data *data)
 		.realbits = 16, \
 		.storagebits = 16, \
 		.endianness = IIO_CPU, \
-	} \
+	}, \
+	.event_spec = _evspec,\
+	.num_event_specs = _evsize,\
 }
 
 static const struct iio_chan_spec ltr501_channels[] = {
-	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0),
+	LTR501_INTENSITY_CHANNEL(0, LTR501_ALS_DATA0, IIO_MOD_LIGHT_BOTH, 0,
+				 ltr501_als_event_spec,
+				 ARRAY_SIZE(ltr501_als_event_spec)),
 	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
 				 BIT(IIO_CHAN_INFO_SCALE) |
-				 BIT(IIO_CHAN_INFO_INT_TIME)),
+				 BIT(IIO_CHAN_INFO_INT_TIME),
+				 NULL, 0),
 	{
 		.type = IIO_PROXIMITY,
 		.address = LTR501_PS_DATA,

@@ -194,6 +249,8 @@ static const struct iio_chan_spec ltr501_channels[] = {
 			.storagebits = 16,
 			.endianness = IIO_CPU,
 		},
+		.event_spec = ltr501_pxs_event_spec,
+		.num_event_specs = ARRAY_SIZE(ltr501_pxs_event_spec),
 	},
 	IIO_CHAN_SOFT_TIMESTAMP(3),
 };

@@ -329,6 +386,185 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 	return -EINVAL;
 }

drivers/iio/light/ltr501.c +51 -0

+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_ALS_THRESH_UP,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_ALS_THRESH_MASK;
+			return IIO_VAL_INT;
+		case IIO_EV_DIR_FALLING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_ALS_THRESH_LOW,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_ALS_THRESH_MASK;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_PROXIMITY:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_PS_THRESH_UP,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_PS_THRESH_MASK;
+			return IIO_VAL_INT;
+		case IIO_EV_DIR_FALLING:
+			ret = regmap_bulk_read(data->regmap,
+					       LTR501_PS_THRESH_LOW,
+					       &thresh_data, 2);
+			if (ret < 0)
+				return ret;
+			*val = thresh_data & LTR501_PS_THRESH_MASK;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+

drivers/iio/light/ltr501.c +181 -1

+	if (val < 0)
+		return -EINVAL;
+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		if (val > LTR501_ALS_THRESH_MASK)
+			return -EINVAL;
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			mutex_lock(&data->lock_als);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_ALS_THRESH_UP,
+						&val, 2);
+			mutex_unlock(&data->lock_als);
+			return ret;
+		case IIO_EV_DIR_FALLING:
+			mutex_lock(&data->lock_als);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_ALS_THRESH_LOW,
+						&val, 2);
+			mutex_unlock(&data->lock_als);
+			return ret;
+		default:
+			return -EINVAL;
+		}
+	case IIO_PROXIMITY:
+		switch (dir) {
+		if (val > LTR501_PS_THRESH_MASK)
+			return -EINVAL;
+		case IIO_EV_DIR_RISING:
+			mutex_lock(&data->lock_ps);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_PS_THRESH_UP,
+						&val, 2);
+			mutex_unlock(&data->lock_ps);
+			return ret;
+		case IIO_EV_DIR_FALLING:
+			mutex_lock(&data->lock_ps);
+			ret = regmap_bulk_write(data->regmap,
+						LTR501_PS_THRESH_LOW,
+						&val, 2);
+			mutex_unlock(&data->lock_ps);
+			return ret;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_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 ltr501_data *data = iio_priv(indio_dev);
+	int ret, status;
+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		ret = regmap_field_read(data->reg_als_intr, &status);
+		if (ret < 0)
+			return ret;
+		return status;
+	case IIO_PROXIMITY:
+		ret = regmap_field_read(data->reg_ps_intr, &status);
+		if (ret < 0)
+			return ret;
+		return status;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_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 ltr501_data *data = iio_priv(indio_dev);
+	int ret;
+
+	/* only 1 and 0 are valid inputs */
+	if (state != 1  || state != 0)
+		return -EINVAL;
+
+	switch (chan->type) {
+	case IIO_INTENSITY:
+		mutex_lock(&data->lock_als);
+		ret = regmap_field_write(data->reg_als_intr, state);
+		mutex_unlock(&data->lock_als);
+		return ret;
+	case IIO_PROXIMITY:
+		mutex_lock(&data->lock_ps);
+		ret = regmap_field_write(data->reg_ps_intr, state);
+		mutex_unlock(&data->lock_ps);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
 static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
 static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.05 0.1 0.2 0.4");

@@ -344,10 +580,21 @@ static const struct attribute_group ltr501_attribute_group = {
 	.attrs = ltr501_attributes,
 };
 
+static const struct iio_info ltr501_info_no_irq = {
+	.read_raw = ltr501_read_raw,
+	.write_raw = ltr501_write_raw,
+	.attrs = &ltr501_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
 static const struct iio_info ltr501_info = {
 	.read_raw = ltr501_read_raw,
 	.write_raw = ltr501_write_raw,
 	.attrs = &ltr501_attribute_group,
+	.read_event_value	= &ltr501_read_thresh,
+	.write_event_value	= &ltr501_write_thresh,
+	.read_event_config	= &ltr501_read_event_config,
+	.write_event_config	= &ltr501_write_event_config,
 	.driver_module = THIS_MODULE,
 };
 

@@ -413,6 +660,36 @@ done:
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t ltr501_interrupt_handler(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct ltr501_data *data = iio_priv(indio_dev);
+	int ret, status;
+
+	ret = regmap_read(data->regmap, LTR501_ALS_PS_STATUS, &status);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"irq read int reg failed\n");
+		return IRQ_HANDLED;
+	}
+
+	if (status & LTR501_STATUS_ALS_INTR)
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_INTENSITY, 0,
+						    IIO_EV_TYPE_THRESH,
+						    IIO_EV_DIR_EITHER),
+			       iio_get_time_ns());
+
+	if (status & LTR501_STATUS_PS_INTR)
+		iio_push_event(indio_dev,
+			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
+						    IIO_EV_TYPE_THRESH,
+						    IIO_EV_DIR_EITHER),
+			       iio_get_time_ns());
+
+	return IRQ_HANDLED;
+}
+
 static int ltr501_init(struct ltr501_data *data)
 {
 	int ret, status;

@@ -492,6 +769,20 @@ static int ltr501_probe(struct i2c_client *client,
 		return PTR_ERR(data->reg_it);
 	}
 
+	data->reg_als_intr = devm_regmap_field_alloc(&client->dev, regmap,
+						     reg_field_als_intr);
+	if (IS_ERR(data->reg_als_intr)) {
+		dev_err(&client->dev, "ALS intr mode reg field init failed\n");
+		return PTR_ERR(data->reg_als_intr);
+	}
+
+	data->reg_ps_intr = devm_regmap_field_alloc(&client->dev, regmap,
+						    reg_field_ps_intr);
+	if (IS_ERR(data->reg_ps_intr)) {
+		dev_err(&client->dev, "PS intr mode reg field init failed.\n");
+		return PTR_ERR(data->reg_ps_intr);
+	}
+
 	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
 	if (ret < 0)
 		return ret;

@@ -499,7 +790,6 @@ static int ltr501_probe(struct i2c_client *client,
 		return -ENODEV;
 
 	indio_dev->dev.parent = &client->dev;
-	indio_dev->info = &ltr501_info;
 	indio_dev->channels = ltr501_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ltr501_channels);
 	indio_dev->name = LTR501_DRV_NAME;

@@ -509,6 +799,23 @@ static int ltr501_probe(struct i2c_client *client,
 	if (ret < 0)
 		return ret;
 
+	if (client->irq > 0) {
+		indio_dev->info = &ltr501_info;
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, ltr501_interrupt_handler,
+						IRQF_TRIGGER_FALLING |
+						IRQF_ONESHOT,
+						"ltr501_thresh_event",
+						indio_dev);
+		if (ret) {
+			dev_err(&client->dev, "request irq (%d) failed\n",
+				client->irq);
+			return ret;
+		}
+	} else {
+		indio_dev->info = &ltr501_info_no_irq;
+	}
+
 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
 					 ltr501_trigger_handler, NULL);
 	if (ret)

Added rate control support for ALS and proximity threshold interrupts.Also, Added support to modify and read ALS & proximity sensor sampling frequency.

LTR-501 supports interrupt rate control using persistence register settings. Writing <n> to persistence register would generate interrupt only if there are <n> consecutive data values outside the threshold range.

Since we don't have any existing ABI's to directly control the persistence register count, we have implemented the rate control using IIO_EV_INFO_PERIOD. _period event attribute represents the amount of time in seconds an event should be true for the device to generate the interrupt. So using _period value and device frequency, persistence count is calculated in driver using following logic.

count = period / measurement_rate

If the given period is not a multiple of measurement rate then we round up the value to next multiple.

This patch also handles change to persistence count whenever there is change in frequency.

Signed-off-by Kuppuswamy Sathyanarayanan <[email protected]>

---
 drivers/iio/light/ltr501.c | 413 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 406 insertions(+), 7 deletions(-)

drivers/iio/light/ltr501.c +406 -7

index 593dbb1..d9b4536 100644
@@ -9,7 +9,7 @@
  *
  * 7-bit I2C slave address 0x23
  *
- * TODO: measurement rate, IR LED characteristics
+ * TODO: IR LED characteristics
  */
 
 #include <linux/module.h>

@@ -29,6 +29,7 @@
 
 #define LTR501_ALS_CONTR 0x80 /* ALS operation mode, SW reset */
 #define LTR501_PS_CONTR 0x81 /* PS operation mode */
+#define LTR501_PS_MEAS_RATE 0x84 /* measurement rate*/
 #define LTR501_ALS_MEAS_RATE 0x85 /* ALS integ time, measurement rate*/
 #define LTR501_PART_ID 0x86
 #define LTR501_MANUFAC_ID 0x87

@@ -41,6 +42,7 @@
 #define LTR501_PS_THRESH_LOW 0x92 /* 11 bit, ps lower threshold */
 #define LTR501_ALS_THRESH_UP 0x97 /* 16 bit, ALS upper threshold */
 #define LTR501_ALS_THRESH_LOW 0x99 /* 16 bit, ALS lower threshold */
+#define LTR501_INTR_PRST 0x9e /* ps thresh, als thresh */
 #define LTR501_MAX_REG 0x9f
 
 #define LTR501_ALS_CONTR_SW_RESET BIT(2)

@@ -58,6 +60,9 @@
 #define LTR501_PS_THRESH_MASK 0x7ff
 #define LTR501_ALS_THRESH_MASK 0xffff
 
+#define LTR501_ALS_DEF_PERIOD 500000
+#define LTR501_PS_DEF_PERIOD 100000
+
 #define LTR501_REGMAP_NAME "ltr501_regmap"
 
 static const int int_time_mapping[] = {100000, 50000, 200000, 400000};

@@ -68,17 +73,171 @@ static const struct reg_field reg_field_als_intr =
 				REG_FIELD(LTR501_INTR, 0, 0);
 static const struct reg_field reg_field_ps_intr =
 				REG_FIELD(LTR501_INTR, 1, 1);
+static const struct reg_field reg_field_als_rate =
+				REG_FIELD(LTR501_ALS_MEAS_RATE, 0, 2);
+static const struct reg_field reg_field_ps_rate =
+				REG_FIELD(LTR501_PS_MEAS_RATE, 0, 3);
+static const struct reg_field reg_field_als_prst =
+				REG_FIELD(LTR501_INTR_PRST, 0, 3);
+static const struct reg_field reg_field_ps_prst =
+				REG_FIELD(LTR501_INTR_PRST, 4, 7);
+
+struct ltr501_samp_table {
+	int freq_val;  /* repetition frequency in micro HZ*/
+	int time_val; /* repetition rate in micro seconds */
+};
 
 struct ltr501_data {
 	struct i2c_client *client;
 	struct mutex lock_als, lock_ps;
 	u8 als_contr, ps_contr;
+	int als_period, ps_period; /* period in micro seconds */
 	struct regmap *regmap;
 	struct regmap_field *reg_it;
 	struct regmap_field *reg_als_intr;
 	struct regmap_field *reg_ps_intr;
+	struct regmap_field *reg_als_rate;
+	struct regmap_field *reg_ps_rate;
+	struct regmap_field *reg_als_prst;
+	struct regmap_field *reg_ps_prst;
+};
+
+static const struct ltr501_samp_table ltr501_als_samp_table[] = {
+			{20000000, 50000}, {10000000, 100000},
+			{5000000, 200000}, {2000000, 500000},
+			{1000000, 1000000}, {500000, 2000000},
+			{500000, 2000000}, {500000, 2000000}
 };
 
+static const struct ltr501_samp_table ltr501_ps_samp_table[] = {
+			{20000000, 50000}, {14285714, 70000},
+			{10000000, 100000}, {5000000, 200000},
+			{2000000, 500000}, {1000000, 1000000},
+			{500000, 2000000}, {500000, 2000000},
+			{500000, 2000000}
+};
+
+static unsigned int ltr501_match_samp_freq(const struct ltr501_samp_table *tab,
+					   int len, int val, int val2)
+{
+	int i, freq;
+
+	freq = val * 1000000 + val2;
+
+	for (i = 0; i < len; i++) {
+		if (tab[i].freq_val == freq)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_als_read_samp_freq(struct ltr501_data *data,
+				     int *val, int *val2)
+{
+	int ret, i;
+
+	ret = regmap_field_read(data->reg_als_rate, &i);
+	if (ret < 0)
+		return ret;
+
+	if (i < 0 || i >= ARRAY_SIZE(ltr501_als_samp_table))
+		return -EINVAL;
+
+	*val = ltr501_als_samp_table[i].freq_val / 1000000;
+	*val2 = ltr501_als_samp_table[i].freq_val % 1000000;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int ltr501_ps_read_samp_freq(struct ltr501_data *data,
+				    int *val, int *val2)
+{
+	int ret, i;
+
+	ret = regmap_field_read(data->reg_ps_rate, &i);
+	if (ret < 0)
+		return ret;
+
+	if (i < 0 || i >= ARRAY_SIZE(ltr501_ps_samp_table))
+		return -EINVAL;
+
+	*val = ltr501_ps_samp_table[i].freq_val / 1000000;
+	*val2 = ltr501_ps_samp_table[i].freq_val % 1000000;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int ltr501_als_write_samp_freq(struct ltr501_data *data,
+				      int val, int val2)
+{
+	int i, ret;
+
+	i = ltr501_match_samp_freq(ltr501_als_samp_table,
+				   ARRAY_SIZE(ltr501_als_samp_table),
+				   val, val2);
+
+	if (i < 0)
+		return i;
+
+	mutex_lock(&data->lock_als);
+	ret = regmap_field_write(data->reg_als_rate, i);
+	mutex_unlock(&data->lock_als);
+
+	return ret;
+}
+
+static int ltr501_ps_write_samp_freq(struct ltr501_data *data,
+				     int val, int val2)
+{
+	int i, ret;
+
+	i = ltr501_match_samp_freq(ltr501_ps_samp_table,
+				   ARRAY_SIZE(ltr501_ps_samp_table),
+				   val, val2);
+
+	if (i < 0)
+		return i;
+
+	mutex_lock(&data->lock_ps);
+	ret = regmap_field_write(data->reg_ps_rate, i);
+	mutex_unlock(&data->lock_ps);
+
+	return ret;
+}
+
+static int ltr501_als_read_samp_period(struct ltr501_data *data, int *val)
+{
+	int ret, i;
+
+	ret = regmap_field_read(data->reg_als_rate, &i);
+	if (ret < 0)
+		return ret;
+
+	if (i < 0 || i >= ARRAY_SIZE(ltr501_als_samp_table))
+		return -EINVAL;
+
+	*val = ltr501_als_samp_table[i].time_val;
+
+	return IIO_VAL_INT;
+}
+
+static int ltr501_ps_read_samp_period(struct ltr501_data *data, int *val)
+{
+	int ret, i;
+
+	ret = regmap_field_read(data->reg_ps_rate, &i);
+	if (ret < 0)
+		return ret;
+
+	if (i < 0 || i >= ARRAY_SIZE(ltr501_ps_samp_table))
+		return -EINVAL;
+
+	*val = ltr501_ps_samp_table[i].time_val;
+
+	return IIO_VAL_INT;
+}
+
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 {
 	int tries = 100;

@@ -177,6 +336,104 @@ static int ltr501_read_ps(struct ltr501_data *data)
 	return status;
 }
 
+static int ltr501_read_intr_prst(struct ltr501_data *data,
+				 enum iio_chan_type type,
+				 int *val2)
+{
+	int ret, samp_period, prst;
+
+	switch (type) {
+	case IIO_INTENSITY:
+		ret = regmap_field_read(data->reg_als_prst, &prst);
+		if (ret < 0)
+			return ret;
+
+		ret = ltr501_als_read_samp_period(data, &samp_period);
+
+		if (ret < 0)
+			return ret;
+		*val2 = samp_period * prst;
+		return IIO_VAL_INT_PLUS_MICRO;
+	case IIO_PROXIMITY:
+		ret = regmap_field_read(data->reg_ps_prst, &prst);
+		if (ret < 0)
+			return ret;
+
+		ret = ltr501_ps_read_samp_period(data, &samp_period);
+
+		if (ret < 0)
+			return ret;
+
+		*val2 = samp_period * prst;
+		return IIO_VAL_INT_PLUS_MICRO;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_write_intr_prst(struct ltr501_data *data,
+				  enum iio_chan_type type,
+				  int val, int val2)
+{
+	int ret, samp_period, new_val;
+	unsigned long period;
+
+	if (val < 0 || val2 < 0)
+		return -EINVAL;
+
+	/* period in microseconds */
+	period = ((val * 1000000) + val2);
+
+	switch (type) {
+	case IIO_INTENSITY:
+		ret = ltr501_als_read_samp_period(data, &samp_period);
+		if (ret < 0)
+			return ret;
+
+		/* period should be atleast equal to sampling period */
+		if (period < samp_period)
+			return -EINVAL;
+
+		new_val = DIV_ROUND_UP(period, samp_period);
+		if (new_val < 0 || new_val > 0x0f)
+			return -EINVAL;
+
+		mutex_lock(&data->lock_als);
+		ret = regmap_field_write(data->reg_als_prst, new_val);
+		mutex_unlock(&data->lock_als);
+		if (ret >= 0)
+			data->als_period = period;
+
+		return ret;
+	case IIO_PROXIMITY:
+		ret = ltr501_ps_read_samp_period(data, &samp_period);
+		if (ret < 0)
+			return ret;
+
+		/* period should be atleast equal to rate */
+		if (period < samp_period)
+			return -EINVAL;
+
+		new_val = DIV_ROUND_UP(period, samp_period);
+		if (new_val < 0 || new_val > 0x0f)
+			return -EINVAL;
+
+		mutex_lock(&data->lock_ps);
+		ret = regmap_field_write(data->reg_ps_prst, new_val);
+		mutex_unlock(&data->lock_ps);
+		if (ret >= 0)
+			data->ps_period = period;
+
+		return ret;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
 static const struct iio_event_spec ltr501_als_event_spec[] = {
 	{
 		.type = IIO_EV_TYPE_THRESH,

@@ -189,7 +446,8 @@ static const struct iio_event_spec ltr501_als_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),
 	},
 
 };

@@ -206,7 +464,8 @@ static const struct iio_event_spec ltr501_pxs_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),
 	},
 };
 

@@ -235,7 +494,8 @@ static const struct iio_chan_spec ltr501_channels[] = {
 				 ARRAY_SIZE(ltr501_als_event_spec)),
 	LTR501_INTENSITY_CHANNEL(1, LTR501_ALS_DATA1, IIO_MOD_LIGHT_IR,
 				 BIT(IIO_CHAN_INFO_SCALE) |
-				 BIT(IIO_CHAN_INFO_INT_TIME),
+				 BIT(IIO_CHAN_INFO_INT_TIME) |
+				 BIT(IIO_CHAN_INFO_SAMP_FREQ),
 				 NULL, 0),
 	{
 		.type = IIO_PROXIMITY,

@@ -320,6 +580,15 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		switch (chan->type) {
+		case IIO_INTENSITY:
+			return ltr501_als_read_samp_freq(data, val, val2);
+		case IIO_PROXIMITY:
+			return ltr501_ps_read_samp_freq(data, val, val2);
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }

@@ -340,7 +609,7 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 			    int val, int val2, long mask)
 {
 	struct ltr501_data *data = iio_priv(indio_dev);
-	int i;
+	int i, ret, freq_val, freq_val2;
 
 	if (iio_buffer_enabled(indio_dev))
 		return -EBUSY;

@@ -382,6 +651,49 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
 		default:
 			return -EINVAL;
 		}
+	case IIO_CHAN_INFO_SAMP_FREQ:
+		switch (chan->type) {
+		case IIO_INTENSITY:
+			ret = ltr501_als_read_samp_freq(data, &freq_val,
+							&freq_val2);
+			if (ret < 0)
+				return ret;
+
+			ret = ltr501_als_write_samp_freq(data, val, val2);
+			if (ret < 0)
+				return ret;
+
+			/* update persistence count when changing frequency */
+			ret = ltr501_write_intr_prst(data, chan->type,
+						     0, data->als_period);
+
+			if (ret < 0)
+				return ltr501_als_write_samp_freq(data,
+								  freq_val,
+								  freq_val2);
+			return ret;
+		case IIO_PROXIMITY:
+			ret = ltr501_ps_read_samp_freq(data, &freq_val,
+						       &freq_val2);
+			if (ret < 0)
+				return ret;
+
+			ret = ltr501_ps_write_samp_freq(data, val, val2);
+			if (ret < 0)
+				return ret;
+
+			/* update persistence count when changing frequency */
+			ret = ltr501_write_intr_prst(data, chan->type,
+						     0, data->ps_period);
+
+			if (ret < 0)
+				return ltr501_ps_write_samp_freq(data,
+								 freq_val,
+								 freq_val2);
+			return ret;
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }

@@ -509,6 +821,55 @@ static int ltr501_write_thresh(struct iio_dev *indio_dev,
 	return -EINVAL;
 }
 
+static int ltr501_read_event(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)
+{
+	int ret;
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		return ltr501_read_thresh(indio_dev, chan, type, dir,
+					  info, val, val2);
+	case IIO_EV_INFO_PERIOD:
+		ret = ltr501_read_intr_prst(iio_priv(indio_dev),
+					    chan->type, val2);
+		*val = *val2 / 1000000;
+		*val2 = *val2 % 1000000;
+		return ret;
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_write_event(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 ltr501_write_thresh(indio_dev, chan, type, dir,
+					   info, val, val2);
+	case IIO_EV_INFO_PERIOD:
+		return ltr501_write_intr_prst(iio_priv(indio_dev), chan->type,
+					      val, val2);
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;
+}
+
 static int ltr501_read_event_config(struct iio_dev *indio_dev,
 				    const struct iio_chan_spec *chan,
 				    enum iio_event_type type,

@@ -568,11 +929,13 @@ static int ltr501_write_event_config(struct iio_dev *indio_dev,
 static IIO_CONST_ATTR(in_proximity_scale_available, "1 0.25 0.125 0.0625");
 static IIO_CONST_ATTR(in_intensity_scale_available, "1 0.005");
 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.05 0.1 0.2 0.4");
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("20 10 5 2 1 0.5");
 
 static struct attribute *ltr501_attributes[] = {
 	&iio_const_attr_in_proximity_scale_available.dev_attr.attr,
 	&iio_const_attr_in_intensity_scale_available.dev_attr.attr,
 	&iio_const_attr_integration_time_available.dev_attr.attr,
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
 	NULL
 };
 

@@ -591,8 +954,8 @@ static const struct iio_info ltr501_info = {
 	.read_raw = ltr501_read_raw,
 	.write_raw = ltr501_write_raw,
 	.attrs = &ltr501_attribute_group,
-	.read_event_value	= &ltr501_read_thresh,
-	.write_event_value	= &ltr501_write_thresh,
+	.read_event_value	= &ltr501_read_event,
+	.write_event_value	= &ltr501_write_event,
 	.read_event_config	= &ltr501_read_event_config,
 	.write_event_config	= &ltr501_write_event_config,
 	.driver_module = THIS_MODULE,

@@ -706,6 +1069,14 @@ static int ltr501_init(struct ltr501_data *data)
 
 	data->ps_contr = status | LTR501_CONTR_ACTIVE;
 
+	ret = ltr501_read_intr_prst(data, IIO_INTENSITY, &data->als_period);
+	if (ret < 0)
+		return ret;
+
+	ret = ltr501_read_intr_prst(data, IIO_PROXIMITY, &data->ps_period);
+	if (ret < 0)
+		return ret;
+
 	return ltr501_write_contr(data, data->als_contr, data->ps_contr);
 }
 

@@ -783,6 +1154,34 @@ static int ltr501_probe(struct i2c_client *client,
 		return PTR_ERR(data->reg_ps_intr);
 	}
 
+	data->reg_als_rate = devm_regmap_field_alloc(&client->dev, regmap,
+						     reg_field_als_rate);
+	if (IS_ERR(data->reg_als_rate)) {
+		dev_err(&client->dev, "ALS samp rate field init failed.\n");
+		return PTR_ERR(data->reg_als_rate);
+	}
+
+	data->reg_ps_rate = devm_regmap_field_alloc(&client->dev, regmap,
+						    reg_field_ps_rate);
+	if (IS_ERR(data->reg_ps_rate)) {
+		dev_err(&client->dev, "PS samp rate field init failed.\n");
+		return PTR_ERR(data->reg_ps_rate);
+	}
+
+	data->reg_als_prst = devm_regmap_field_alloc(&client->dev, regmap,
+						     reg_field_als_prst);
+	if (IS_ERR(data->reg_als_prst)) {
+		dev_err(&client->dev, "ALS prst reg field init failed\n");
+		return PTR_ERR(data->reg_als_prst);
+	}
+
+	data->reg_ps_prst = devm_regmap_field_alloc(&client->dev, regmap,
+						    reg_field_ps_prst);
+	if (IS_ERR(data->reg_ps_prst)) {
+		dev_err(&client->dev, "PS prst reg field init failed.\n");
+		return PTR_ERR(data->reg_ps_prst);
+	}
+
 	ret = regmap_read(data->regmap, LTR501_PART_ID, &partid);
 	if (ret < 0)
 		return ret;