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]>

---
 drivers/iio/light/ltr501.c | 114 +++++++++++++++++++++++++++++++--------------
 1 file changed, 80 insertions(+), 34 deletions(-)

drivers/iio/light/ltr501.c +80 -34

index 62b7072..84ee2b3 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);
 	}

@@ -76,16 +80,24 @@ static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
 	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) { \

@@ -218,16 +230,18 @@ 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;
 		}

@@ -255,13 +269,13 @@ 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 = 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)

@@ -273,7 +287,7 @@ 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));
 

@@ -289,8 +303,8 @@ 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))

@@ -300,10 +314,11 @@ 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,

@@ -317,43 +332,75 @@ 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_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
 	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;

@@ -385,9 +432,8 @@ error_unreg_buffer:
 
 static int ltr501_powerdown(struct ltr501_data *data)
 {
-	return ltr501_write_contr(data->client,
-		data->als_contr & ~LTR501_CONTR_ACTIVE,
-		data->ps_contr & ~LTR501_CONTR_ACTIVE);
+	return ltr501_write_contr(data, data->als_contr & ~LTR501_CONTR_ACTIVE,
+				  data->ps_contr & ~LTR501_CONTR_ACTIVE);
 }
 
 static int ltr501_remove(struct i2c_client *client)

@@ -414,7 +460,7 @@ 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

Quoted 5 lines

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

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

Looks good. Applied to the togreg branch of iio.git Initially pushed out as testign for the autobuilders to play with it.

Note I hand applied this as there was a lot of realignment stuff in a recent patch from Daniel.

As he'd gone to the effort to make checkpatch.pl --strict pass it I did the same and cleaned up a few corners (nothing remotely significant!)

If you could take a look at the result and check I didn't do anything silly
that would be great!

Thanks,

Jonathan

Quoted 276 lines

---
 drivers/iio/light/ltr501.c | 114
+++++++++++++++++++++++++++++++--------------
 1 file changed, 80 insertions(+), 34 deletions(-)

drivers/iio/light/ltr501.c +20 -8

index 62b7072..84ee2b3 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);
 	}

@@ -76,16 +80,24 @@ static int ltr501_read_als(struct ltr501_data *data,
 __le16 buf[2])
 	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) { \

drivers/iio/light/ltr501.c +6 -4

@@ -218,16 +230,18 @@ 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;

drivers/iio/light/ltr501.c +3 -3

 		}

@@ -255,13 +269,13 @@ 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 = 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)

drivers/iio/light/ltr501.c +3 -3

@@ -273,7 +287,7 @@ 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));

@@ -289,8 +303,8 @@ 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;

drivers/iio/light/ltr501.c +3 -2

 		if (test_bit(0, indio_dev->active_scan_mask))

@@ -300,10 +314,11 @@ 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;
 	}
 

drivers/iio/light/ltr501.c +42 -10

 	iio_push_to_buffers_with_timestamp(indio_dev, buf,

@@ -317,43 +332,75 @@ 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_probe(struct i2c_client *client,
 			  const struct i2c_device_id *id)
 {
 	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;
 

drivers/iio/light/ltr501.c +2 -3

 	indio_dev->dev.parent = &client->dev;

@@ -385,9 +432,8 @@ error_unreg_buffer:
 
 static int ltr501_powerdown(struct ltr501_data *data)
 {
-	return ltr501_write_contr(data->client,
-		data->als_contr & ~LTR501_CONTR_ACTIVE,
-		data->ps_contr & ~LTR501_CONTR_ACTIVE);
+	return ltr501_write_contr(data, data->als_contr &
 ~LTR501_CONTR_ACTIVE,
+				  data->ps_contr & ~LTR501_CONTR_ACTIVE);
 }
 

static int ltr501_remove(struct i2c_client *client)

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

@@ -414,7 +460,7 @@ 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 | 87 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

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

index 84ee2b3..22769c8 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 +82 -1

+
 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 +80,58 @@ 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 = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);

@@ -119,7 +177,7 @@ 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,

@@ -195,6 +253,13 @@ 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;
 }

@@ -245,16 +310,30 @@ 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
 };
 

@@ -396,6 +475,12 @@ 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_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;

Quoted 4 lines

Added support to modify and read ALS integration time.

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

Cool, didn't know about this regmap field stuff before. Not exactly heavily
used but looks helpful!

A few questions inline..

1) A spot where a variable name change would make it easier to follow.

2) Why are the struct reg_field not defined as const in the regmap_field allocators? Here it gives the impression we are restricting ourselves to one instance of this chip, but in reality they seem to actually be const so we aren't.

messy :(

Quoted 19 lines

---
 drivers/iio/light/ltr501.c | 87
+++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

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

index 84ee2b3..22769c8 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 +50,16 @@
 

drivers/iio/light/ltr501.c line 55

Quoted 5 lines

drivers/iio/light/ltr501.c +3 -0

 #define LTR501_REGMAP_NAME "ltr501_regmap"
 
+static int int_time_mapping[] = {100000, 50000, 200000, 400000};
+
+static struct reg_field reg_it = REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);

Naming could be clearer. The reg_it here and the regmap_field below are different structures, but their name doesn't make this clear.

Also, why is the above not const? Obviously regmap doesn't take a const but I can't see why not... Mark?

It is only used to initialize elements (by copying) in the regmap_field that allocator of which it is passed to.

Quoted 132 lines

drivers/iio/light/ltr501.c +54 -0

+
 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 +80,58 @@ 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])

{

drivers/iio/light/ltr501.c +8 -1

 	int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);

@@ -119,7 +177,7 @@ 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,

@@ -195,6 +253,13 @@ 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;

}

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

@@ -245,16 +310,30 @@ 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

};

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

@@ -396,6 +475,12 @@ static int ltr501_probe(struct i2c_client *client,
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);

drivers/iio/light/ltr501.c static int ltr501_probe(struct i2c_client *client, · line 486

Quoted 10 lines

drivers/iio/light/ltr501.c +6 -0

 
+	data->reg_it = devm_regmap_field_alloc(&client->dev, regmap, reg_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;

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Hi Jonathan,

Quoted 9 lines · Kuppuswamy Sathyanarayanan

Quoted 4 lines

Added support to modify and read ALS integration time.

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

Cool, didn't know about this regmap field stuff before. Not exactly heavily
used but looks helpful!

yes. It simplifies the bit wise manipulations and makes it more readable. Avoids use of masks and logical operations.

Quoted 4 lines

A few questions inline..

1) A spot where a variable name change would make it easier to follow.

Fixed it in next set.

Quoted 4 lines

2) Why are the struct reg_field not defined as const in the regmap_field allocators? Here it gives the impression we are restricting ourselves to one instance of this chip, but in reality they seem to actually be const so we aren't.

There are few use cases in kernel where they allocate the reg_map fields in an array. In these cases same reg_field can be used with few index manipulations. Add const to allocators would restrict users in doing that.

Quoted 22 lines

messy :(

Quoted 19 lines

---
 drivers/iio/light/ltr501.c | 87
+++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 86 insertions(+), 1 deletion(-)

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

index 84ee2b3..22769c8 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 +50,16 @@
 

Quoted 7 lines

drivers/iio/light/ltr501.c line 55

Quoted 5 lines

drivers/iio/light/ltr501.c +3 -0

 #define LTR501_REGMAP_NAME "ltr501_regmap"
 
+static int int_time_mapping[] = {100000, 50000, 200000, 400000};
+
+static struct reg_field reg_it = REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);

Naming could be clearer. The reg_it here and the regmap_field below are different structures, but their name doesn't make this clear.

Fixed it in next set.

Quoted 3 lines

Also, why is the above not const? Obviously regmap doesn't take a const but I can't see why not... Mark?

I agree. Fixed it in next set.

Quoted 135 lines

It is only used to initialize elements (by copying) in the regmap_field that allocator of which it is passed to.

Quoted 132 lines

drivers/iio/light/ltr501.c +54 -0

+
 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 +80,58 @@ 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])

{

drivers/iio/light/ltr501.c +8 -1

 	int ret = ltr501_drdy(data, LTR501_STATUS_ALS_RDY);

@@ -119,7 +177,7 @@ 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,

@@ -195,6 +253,13 @@ 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;

}

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

@@ -245,16 +310,30 @@ 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

};

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

@@ -396,6 +475,12 @@ static int ltr501_probe(struct i2c_client *client,
 	mutex_init(&data->lock_als);
 	mutex_init(&data->lock_ps);
 

Quoted 16 lines

drivers/iio/light/ltr501.c static int ltr501_probe(struct i2c_client *client, · line 486

Quoted 10 lines

drivers/iio/light/ltr501.c +6 -0

+	data->reg_it = devm_regmap_field_alloc(&client->dev, regmap, reg_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;

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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 | 310 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 304 insertions(+), 6 deletions(-)

drivers/iio/light/ltr501.c +304 -6

index 22769c8..8ead137 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)

@@ -43,16 +49,22 @@
 #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"
 
 static int int_time_mapping[] = {100000, 50000, 200000, 400000};
 
 static struct reg_field reg_it = REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
+static struct reg_field reg_als_intr = REG_FIELD(LTR501_INTR, 0, 0);
+static struct reg_field reg_ps_intr = REG_FIELD(LTR501_INTR, 1, 1);
 
 struct ltr501_data {
 	struct i2c_client *client;

@@ -60,6 +72,8 @@ 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)

@@ -158,7 +172,41 @@ 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), \

@@ -171,13 +219,17 @@ 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_SCALE) | BIT(IIO_CHAN_INFO_INT_TIME),
+		NULL, 0),
 	{
 		.type = IIO_PROXIMITY,
 		.address = LTR501_PS_DATA,

@@ -190,6 +242,8 @@ 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),
 };

@@ -326,6 +380,180 @@ 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");

@@ -341,10 +569,21 @@ 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,
 };
 

@@ -409,6 +648,36 @@ 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;

@@ -481,6 +750,20 @@ 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_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_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;

@@ -489,7 +772,6 @@ 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;

@@ -499,6 +781,22 @@ 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 | 389 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 382 insertions(+), 7 deletions(-)

drivers/iio/light/ltr501.c +16 -1

index 8ead137..d635ff4 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 int int_time_mapping[] = {100000, 50000, 200000, 400000};

@@ -65,17 +70,119 @@ static int int_time_mapping[] = {100000, 50000, 200000, 400000};
 static struct reg_field reg_it = REG_FIELD(LTR501_ALS_MEAS_RATE, 3, 4);
 static struct reg_field reg_als_intr = REG_FIELD(LTR501_INTR, 0, 0);
 static struct reg_field reg_ps_intr = REG_FIELD(LTR501_INTR, 1, 1);
+static struct reg_field reg_als_rate = REG_FIELD(LTR501_ALS_MEAS_RATE, 0, 2);
+static struct reg_field reg_ps_rate = REG_FIELD(LTR501_PS_MEAS_RATE, 0, 3);
+static struct reg_field reg_als_prst = REG_FIELD(LTR501_INTR_PRST, 0, 3);
+static struct reg_field reg_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 */

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

+static struct ltr501_samp_table ps_sampling_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(struct ltr501_samp_table *table,
+					   int len, int val, int val2)
+{
+	int i, freq;
+
+	freq = val * 1000000 + val2;
+
+	for (i = 0; i < len; i++) {
+		if (table[i].freq_val == freq)
+			return i;
+	}
+
+	return -EINVAL;
+}
+
+static int ltr501_read_samp_freq(struct regmap_field *field,
+			   struct ltr501_samp_table *freq,
+			   int len, int *val, int *val2)
+{
+	int ret, i;
+
+	ret = regmap_field_read(field, &i);
+	if (ret < 0)
+		return ret;
+
+	if (i < 0 || i >= len)
+		return -EINVAL;
+
+	*val = freq[i].freq_val / 1000000;
+	*val2 = freq[i].freq_val % 1000000;
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int ltr501_write_samp_freq(struct ltr501_data *data,
+				struct regmap_field *field,
+				struct ltr501_samp_table *freq,
+				int len, int val, int val2)
+{
+	int i, ret;
+
+	i = ltr501_match_samp_freq(als_sampling_table,
+				   ARRAY_SIZE(als_sampling_table),
+				   val, val2);
+

drivers/iio/light/ltr501.c +74 -0

+static int ltr501_read_samp_rate(struct regmap_field *field,
+			   struct ltr501_samp_table *table,
+			   int len, int *val)
+{
+	int ret, i;
+
+	ret = regmap_field_read(field, &i);
+	if (ret < 0)
+		return ret;
+
+	if (i < 0 || i >= len)
+		return -EINVAL;
+
+	*val = table[i].time_val;
+
+	return IIO_VAL_INT;
+}
+
 static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
 {
 	int tries = 100;

@@ -172,6 +279,116 @@ 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, rate, prst;
+
+	switch (type) {
+	case IIO_INTENSITY:
+		ret = regmap_field_read(data->reg_als_prst, &prst);
+		if (ret < 0)
+			return ret;
+
+		ret = ltr501_read_samp_rate(data->reg_als_rate,
+					    als_sampling_table,
+					    ARRAY_SIZE(als_sampling_table),
+					    &rate);
+
+		if (ret < 0)
+			return ret;
+		*val2 = rate * 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_read_samp_rate(data->reg_ps_rate,
+					    ps_sampling_table,
+					    ARRAY_SIZE(ps_sampling_table),
+					    &rate);
+
+		if (ret < 0)
+			return ret;
+
+		*val2 = rate * 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, rate, new_val;
+	unsigned long period;
+
+	if (val < 0 || val2 < 0)
+		return -EINVAL;
+
+	/* period in microseconds */
+	period = ((val * 1000000) + val2);
+

drivers/iio/light/ltr501.c +208 -6

+		if (period < rate)
+			return -EINVAL;
+
+		new_val = DIV_ROUND_UP(period, rate);
+		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_read_samp_rate(data->reg_ps_rate,
+					    ps_sampling_table,
+					    ARRAY_SIZE(ps_sampling_table),
+					    &rate);
+		if (ret < 0)
+			return ret;
+
+		/* period should be atleast equal to rate */
+		if (period < rate)
+			return -EINVAL;
+
+		new_val = DIV_ROUND_UP(period, rate);
+		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,

@@ -184,7 +401,8 @@ 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),
 	},
 
 };

@@ -201,7 +419,8 @@ 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),
 	},
 };
 

@@ -228,7 +447,8 @@ static const struct iio_chan_spec ltr501_channels[] = {
 	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_SCALE) | BIT(IIO_CHAN_INFO_INT_TIME) |
+		BIT(IIO_CHAN_INFO_SAMP_FREQ),
 		NULL, 0),
 	{
 		.type = IIO_PROXIMITY,

@@ -314,6 +534,23 @@ 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:
+			ret = ltr501_read_samp_freq(data->reg_als_rate,
+						als_sampling_table,
+						ARRAY_SIZE(als_sampling_table),
+						val, val2);
+			return ret;
+		case IIO_PROXIMITY:
+			ret = ltr501_read_samp_freq(data->reg_ps_rate,
+						ps_sampling_table,
+						ARRAY_SIZE(ps_sampling_table),
+						val, val2);
+			return ret;
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }

@@ -334,7 +571,7 @@ 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;

@@ -376,6 +613,57 @@ 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_read_samp_freq(data->reg_als_rate,
+						als_sampling_table,
+						ARRAY_SIZE(als_sampling_table),
+						&freq_val, &freq_val2);
+			ret = ltr501_write_samp_freq(data, data->reg_als_rate,
+						als_sampling_table,
+						ARRAY_SIZE(als_sampling_table),
+						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_write_samp_freq(data,
+						data->reg_als_rate,
+						als_sampling_table,
+						ARRAY_SIZE(als_sampling_table),
+						freq_val, freq_val2);
+			return ret;
+		case IIO_PROXIMITY:
+			ret = ltr501_read_samp_freq(data->reg_ps_rate,
+						ps_sampling_table,
+						ARRAY_SIZE(ps_sampling_table),
+						&freq_val, &freq_val2);
+			ret = ltr501_write_samp_freq(data, data->reg_ps_rate,
+						ps_sampling_table,
+						ARRAY_SIZE(ps_sampling_table),
+						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_write_samp_freq(data,
+						data->reg_ps_rate,
+						ps_sampling_table,
+						ARRAY_SIZE(ps_sampling_table),
+						freq_val, freq_val2);
+			return ret;
+		default:
+			return -EINVAL;
+		}
 	}
 	return -EINVAL;
 }

@@ -499,6 +787,55 @@ 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,

@@ -557,11 +894,13 @@ 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
 };
 

@@ -580,8 +919,8 @@ 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,

@@ -694,6 +1033,14 @@ 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);
 }
 

@@ -764,6 +1111,34 @@ 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_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_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_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_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;