Add driver for veml6030 ambient light sensor

veml6030 is an ambient light sensor from Vishay semiconductors. It has 16-bit resolution, supports both ambient light measurement and white channel which is more responsive to wider wavelength spectrum. It has flexible power saving, integration time and gain options. Communication with host is over I2C.

Signed-off-by Rishi Gupta <[email protected]>

---
Changes in v2:
* Added comma after CH_WHITE in enum veml6030_chan so it can be extended
* Removed .scan_type as driver doesn't use buffered mode
* Removed iio_device_unregister() as kernel will take care of cleaning

 drivers/iio/light/Kconfig    |  11 +
 drivers/iio/light/Makefile   |   1 +
 drivers/iio/light/veml6030.c | 633 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 645 insertions(+)
 create mode 100644 drivers/iio/light/veml6030.c

drivers/iio/light/Kconfig +11 -0

index 08d7e1e..e455cec 100644
@@ -495,6 +495,17 @@ config VCNL4035
 	  To compile this driver as a module, choose M here: the
 	  module will be called vcnl4035.
 
+config VEML6030
+	tristate "VEML6030 ambient light sensor"
+	select REGMAP_I2C
+	depends on I2C
+	help
+	  Say Y here if you want to build a driver for the Vishay VEML6030
+	  ambient light sensor (ALS).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called veml6030.
+
 config VEML6070
 	tristate "VEML6070 UV A light sensor"
 	depends on I2C

drivers/iio/light/Makefile +1 -0

index 00d1f9b..5e0c40b 100644
@@ -48,6 +48,7 @@ obj-$(CONFIG_TSL4531)		+= tsl4531.o
 obj-$(CONFIG_US5182D)		+= us5182d.o
 obj-$(CONFIG_VCNL4000)		+= vcnl4000.o
 obj-$(CONFIG_VCNL4035)		+= vcnl4035.o
+obj-$(CONFIG_VEML6030)		+= veml6030.o
 obj-$(CONFIG_VEML6070)		+= veml6070.o
 obj-$(CONFIG_VL6180)		+= vl6180.o
 obj-$(CONFIG_ZOPT2201)		+= zopt2201.o

drivers/iio/light/veml6030.c new file +54 -0

new file mode 100644
index 0000000..3f6b2bd
@@ -0,0 +1,633 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VEML6030 Ambient Light Sensor
+ *
+ * Copyright (c) 2019, Rishi Gupta <[email protected]>
+ *
+ * Datasheet: https://www.vishay.com/docs/84366/veml6030.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/regmap.h>
+#include <linux/mutex.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+
+/* Device registers */
+#define VEML6030_REG_ALS_CONF    0x00
+#define VEML6030_REG_ALS_WH      0x01
+#define VEML6030_REG_ALS_WL      0x02
+#define VEML6030_REG_ALS_PSM     0x03
+#define VEML6030_REG_ALS_DATA    0x04
+#define VEML6030_REG_WHITE_DATA  0x05
+#define VEML6030_REG_ALS_INT     0x06
+
+/* Bit masks for specific functionality */
+#define VEML6030_ALS_IT       GENMASK(9, 6)
+#define VEML6030_PSM          GENMASK(2, 1)
+#define VEML6030_ALS_PERS     GENMASK(5, 4)
+#define VEML6030_ALS_GAIN     GENMASK(12, 11)
+#define VEML6030_PSM_EN       BIT(0)
+#define VEML6030_INT_TH_LOW   BIT(15)
+#define VEML6030_INT_TH_HIGH  BIT(14)
+#define VEML6030_ALS_INT_EN   BIT(1)
+#define VEML6030_ALS_SD       BIT(0)
+
+struct veml6030_data {
+	struct i2c_client *client;
+	struct regmap *regmap;
+};
+
+static IIO_CONST_ATTR_INT_TIME_AVAIL("0.025 0.05 0.1 0.2 0.4 0.8");
+
+static struct attribute *veml6030_attributes[] = {
+	&iio_const_attr_integration_time_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group veml6030_attr_group = {
+	.attrs = veml6030_attributes,

drivers/iio/light/veml6030.c new file +51 -0

+}
+
+/*
+ * Persistence = 1/2/4/8 x integration time
+ * Minimum time for which light readings must stay above configured
+ * threshold to assert interrupt.
+ */
+static ssize_t veml6030_persistence_available(struct iio_dev *indio_dev,
+	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+	return sprintf(buf, "%s\n", "1 2 4 8");
+}
+
+/*
+ * Power saving modes supported.
+ * 1/2/3/4 corresponds to PSM modes 1/2/3/4 respectively.
+ */
+static ssize_t veml6030_psm_available(struct iio_dev *indio_dev,
+	uintptr_t private, const struct iio_chan_spec *chan, char *buf)
+{
+	return sprintf(buf, "%s\n", "1 2 3 4");
+}
+
+ssize_t veml6030_set_psm(struct iio_dev *indio_dev, uintptr_t priv,
+			const struct iio_chan_spec *chan, const char *buf,
+			size_t len)
+{
+	int ret;
+	unsigned int val;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = kstrtouint(buf, 0, &val);
+	if (ret < 0)
+		return ret;
+
+	if (val < 1 || val > 4)
+		return -EINVAL;
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_PSM,
+				 VEML6030_PSM | VEML6030_PSM_EN, val - 1);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't update psm value %d\n", ret);
+		return ret;
+	}
+
+	return len;
+}
+
+#define VEML6030_AVAIL(_name, _read) \
+{ \

drivers/iio/light/veml6030.c new file +27 -0

+	{ },
+};
+
+static const struct iio_event_spec veml6030_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_PERIOD),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
+/*
+ * This is used to specify both scan index and numerical
+ * channel number in channel specifications.
+ */

drivers/iio/light/veml6030.c new file +129 -0

+		.ext_info = veml6030_ext_info,
+	},
+	{
+		.type = IIO_INTENSITY,
+		.channel = CH_WHITE,
+		.modified = 1,
+		.channel2 = IIO_MOD_LIGHT_BOTH,
+		.scan_index = CH_WHITE,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
+	},
+};
+
+static const struct regmap_config veml6030_regmap_config = {
+	.name = "veml6030_regmap",
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = VEML6030_REG_ALS_INT,
+	.val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+static int veml6030_set_als_gain(struct iio_dev *indio_dev,
+						int val, int val2)
+{
+	int ret, gain;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val == 0 && val2 == 125000)
+		gain = 0x02;
+	else if (val == 0 && val2 == 250000)
+		gain = 0x03;
+	else if (val == 1 && val2 == 0)
+		gain = 0x00;
+	else if (val == 2 && val2 == 0)
+		gain = 0x01;
+	else
+		return -EINVAL;
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+					VEML6030_ALS_GAIN, gain);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't set ALS gain %d\n", ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int veml6030_set_als_persistence(struct iio_dev *indio_dev,
+						int val, int val2)
+{
+	int ret;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val < 0 || val > 8 || hweight8(val) != 1 || val2)
+		return -EINVAL;
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+					VEML6030_ALS_PERS, val);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't set persistence value %d\n", ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+static int veml6030_set_als_threshold(struct iio_dev *indio_dev,
+						int val, int val2, int dir)
+{
+	int ret;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val > 0xFFFF || val < 0 || val2)
+		return -EINVAL;
+
+	if (dir == IIO_EV_DIR_RISING) {
+		ret = regmap_write(data->regmap, VEML6030_REG_ALS_WH, val);
+		if (ret)
+			dev_err(&data->client->dev,
+					"can't set high threshold %d\n", ret);
+	} else {
+		ret = regmap_write(data->regmap, VEML6030_REG_ALS_WL, val);
+		if (ret)
+			dev_err(&data->client->dev,
+					"can't set low threshold %d\n", ret);
+	}
+
+	return ret;
+}
+
+static int veml6030_set_integration_time(struct iio_dev *indio_dev,
+						int val, int val2)
+{
+	int ret, int_time;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val)
+		return -EINVAL;
+
+	switch (val2) {
+	case 25000:
+		int_time = 12;
+		break;
+	case 50000:
+		int_time = 8;
+		break;
+	case 100000:
+		int_time = 0;
+		break;
+	case 200000:
+		int_time = 1;
+		break;
+	case 400000:
+		int_time = 2;
+		break;
+	case 800000:
+		int_time = 3;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+					VEML6030_ALS_IT, int_time);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't update integration time %d\n", ret);

drivers/iio/light/veml6030.c new file +31 -0

+ */
+static int veml6030_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	int ret, rdval;
+	struct veml6030_data *data = iio_priv(indio_dev);
+	struct regmap *regmap = data->regmap;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			ret = regmap_read(regmap, VEML6030_REG_ALS_DATA, &rdval);
+			if (ret < 0) {
+				dev_err(&data->client->dev, "can't read ALS data\n");
+				return ret;
+			}
+			*val = rdval;
+			return IIO_VAL_INT;
+		case IIO_INTENSITY:
+			ret = regmap_read(regmap, VEML6030_REG_WHITE_DATA, &rdval);
+			if (ret < 0) {
+				dev_err(&data->client->dev, "can't read white data\n");
+				return ret;
+			}
+			*val = rdval;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}

drivers/iio/light/veml6030.c new file +34 -0

+	case IIO_CHAN_INFO_INT_TIME:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			return veml6030_set_integration_time(indio_dev, val, val2);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			return veml6030_set_als_gain(indio_dev, val, val2);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6030_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)
+{
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		return veml6030_set_als_threshold(indio_dev, val, val2, dir);
+	case IIO_EV_INFO_PERIOD:
+		return veml6030_set_als_persistence(indio_dev, val, val2);
+	default:
+		return -EINVAL;
+	}
+
+	return -EINVAL;

drivers/iio/light/veml6030.c new file +26 -0

+		return -EINVAL;
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+					VEML6030_ALS_INT_EN, state);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't enable threshold interrupt %d\n", ret);
+		return ret;
+	}
+
+	return ret;
+}
+
+static const struct iio_info veml6030_info = {
+	.read_raw  = veml6030_read_raw,
+	.write_raw = veml6030_write_raw,
+	.write_event_value	= veml6030_write_thresh,
+	.write_event_config	= veml6030_write_interrupt_config,
+	.attrs = &veml6030_attr_group,
+};
+
+static irqreturn_t veml6030_event_handler(int irq, void *private)
+{
+	int ret, reg, evtdir;
+	struct iio_dev *indio_dev = private;
+	struct veml6030_data *data = iio_priv(indio_dev);

drivers/iio/light/veml6030.c new file +17 -0

+		return IRQ_HANDLED;
+
+	if (reg & VEML6030_INT_TH_HIGH)
+		evtdir = IIO_EV_DIR_RISING;
+	else
+		evtdir = IIO_EV_DIR_FALLING;
+
+	iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY,
+					0, IIO_EV_TYPE_THRESH, evtdir),
+					iio_get_time_ns(indio_dev));
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Corresponding to 1200 ms as refresh time, set ALS gain to
+ * ALS gain x 2, integration time to 200 ms and PSM to mode 2.

drivers/iio/light/veml6030.c new file +23 -0

+	if (ret) {
+		dev_err(&client->dev, "can't setup ALS configs %d\n", ret);
+		return ret;
+	}
+
+	/* Wait 4 ms to let processor & oscillator start correctly */
+	usleep_range(3990, 4000);
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_PSM,
+				 VEML6030_PSM | VEML6030_PSM_EN, 0x03);
+	if (ret) {
+		dev_err(&client->dev, "can't setup defaults for PSM %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(data->regmap, VEML6030_REG_ALS_WH, 0xFFFF);
+	if (ret) {
+		dev_err(&client->dev, "can't read high threshold %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(data->regmap, VEML6030_REG_ALS_WL, 0x0000);
+	if (ret) {

drivers/iio/light/veml6030.c new file +31 -0

+	}
+
+	return ret;
+}
+
+static int veml6030_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	int ret;
+	struct veml6030_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "i2c adapter doesn't support plain i2c\n");
+		return -EOPNOTSUPP;
+	}
+
+	regmap = devm_regmap_init_i2c(client, &veml6030_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "can't setup regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;

drivers/iio/light/veml6030.c new file +6 -0

+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, veml6030_event_handler,
+						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						"veml6030", indio_dev);
+		if (ret < 0) {
+			dev_err(&client->dev,

drivers/iio/light/veml6030.c new file +7 -0

+	}
+
+	return ret;
+}
+
+static int veml6030_runtime_resume(struct device *dev)
+{

drivers/iio/light/veml6030.c new file +19 -0

+	}
+
+	return ret;
+}
+
+static const struct dev_pm_ops veml6030_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(veml6030_runtime_suspend,
+				veml6030_runtime_resume, NULL)
+};
+#endif
+
+static const struct of_device_id veml6030_of_match[] = {
+	{ .compatible = "vishay,veml6030" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, veml6030_of_match);
+

drivers/iio/light/veml6030.c new file +11 -0

+#endif
+	},
+	.probe = veml6030_probe,
+	.remove = veml6030_remove,
+	.id_table = veml6030_id,
+};
+module_i2c_driver(veml6030_driver);
+
+MODULE_AUTHOR("Rishi Gupta <[email protected]>");
+MODULE_DESCRIPTION("VEML6030 Ambient Light Sensor");
+MODULE_LICENSE("GPL v2");

veml6030 is an ambient light sensor from Vishay semiconductors. It has 16-bit resolution, supports both ambient light measurement and white channel which is more responsive to wider wavelength spectrum. It has flexible power saving, integration time and gain options. Communication with host is over I2C.

Signed-off-by Rishi Gupta <[email protected]>

---
Changes in v4:
* None

Changes in v3:
* Added appnote link in topmost comments section
* Dropped 'return ret' statements wherever not needed
* Removed .scan_index from channel specifications, not needed
* If irq is not enabled, events interfaces are not exposed now
* Return IRQ_NONE for spurious interrupt
* Removed CONFIG_PM, added __maybe_unused in power routines
* Removed of_match_ptr when specifying DT device id to match
* Corrected & documented sequence in veml6030_write_interrupt_config()
* Removed veml6030_remove() & added devm_add_action_or_reset functionality
* Added support to read integration time, gain, thresholds, period
* Removed including mutex.h not needed
* Set 100 ms integration & 1/8 gain during probe for better accuracy
* Used IIO_CONST_ATTR to create sysfs entries "_available"
* Minor cosmetics like everything in lower case

Changes in v2:
* Added comma after CH_WHITE in enum veml6030_chan so it can be extended
* Removed .scan_type as driver doesn't use buffered mode
* Removed iio_device_unregister() as kernel will take care of cleaning

 drivers/iio/light/Kconfig    |  11 +
 drivers/iio/light/Makefile   |   1 +
 drivers/iio/light/veml6030.c | 903 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 915 insertions(+)
 create mode 100644 drivers/iio/light/veml6030.c

drivers/iio/light/Kconfig +11 -0

index 4a1a883..f9d27ef 100644
@@ -496,6 +496,17 @@ config VCNL4035
 	  To compile this driver as a module, choose M here: the
 	  module will be called vcnl4035.
 
+config VEML6030
+	tristate "VEML6030 ambient light sensor"
+	select REGMAP_I2C
+	depends on I2C
+	help
+	  Say Y here if you want to build a driver for the Vishay VEML6030
+	  ambient light sensor (ALS).
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called veml6030.
+
 config VEML6070
 	tristate "VEML6070 UV A light sensor"
 	depends on I2C

drivers/iio/light/Makefile +1 -0

index 00d1f9b..5e0c40b 100644
@@ -48,6 +48,7 @@ obj-$(CONFIG_TSL4531)		+= tsl4531.o
 obj-$(CONFIG_US5182D)		+= us5182d.o
 obj-$(CONFIG_VCNL4000)		+= vcnl4000.o
 obj-$(CONFIG_VCNL4035)		+= vcnl4035.o
+obj-$(CONFIG_VEML6030)		+= veml6030.o
 obj-$(CONFIG_VEML6070)		+= veml6070.o
 obj-$(CONFIG_VL6180)		+= vl6180.o
 obj-$(CONFIG_ZOPT2201)		+= zopt2201.o

drivers/iio/light/veml6030.c new file +525 -0

new file mode 100644
index 0000000..d0d4e42
@@ -0,0 +1,903 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VEML6030 Ambient Light Sensor
+ *
+ * Copyright (c) 2019, Rishi Gupta <[email protected]>
+ *
+ * Datasheet: https://www.vishay.com/docs/84366/veml6030.pdf
+ * Appnote-84367: https://www.vishay.com/docs/84367/designingveml6030.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/regmap.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+
+/* Device registers */
+#define VEML6030_REG_ALS_CONF   0x00
+#define VEML6030_REG_ALS_WH     0x01
+#define VEML6030_REG_ALS_WL     0x02
+#define VEML6030_REG_ALS_PSM    0x03
+#define VEML6030_REG_ALS_DATA   0x04
+#define VEML6030_REG_WH_DATA    0x05
+#define VEML6030_REG_ALS_INT    0x06
+
+/* Bit masks for specific functionality */
+#define VEML6030_ALS_IT       GENMASK(9, 6)
+#define VEML6030_PSM          GENMASK(2, 1)
+#define VEML6030_ALS_PERS     GENMASK(5, 4)
+#define VEML6030_ALS_GAIN     GENMASK(12, 11)
+#define VEML6030_PSM_EN       BIT(0)
+#define VEML6030_INT_TH_LOW   BIT(15)
+#define VEML6030_INT_TH_HIGH  BIT(14)
+#define VEML6030_ALS_INT_EN   BIT(1)
+#define VEML6030_ALS_SD       BIT(0)
+
+/*
+ * The resolution depends on both gain and integration time. The
+ * cur_resolution stores one of the resolution mentioned in the
+ * table during startup and gets updated whenever integration time
+ * or gain is changed.
+ *
+ * Table 'resolution and maximum detection range' in appnote 84367
+ * is visualized as a 2D array. The cur_gain stores index of gain
+ * in this table (0-3) while the cur_integration_time holds index
+ * of integration time (0-5).
+ */
+struct veml6030_data {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	int cur_resolution;
+	int cur_gain;
+	int cur_integration_time;
+};
+
+/* Integration time available in seconds */
+static IIO_CONST_ATTR(in_illuminance_integration_time_available,
+				"0.025 0.05 0.1 0.2 0.4 0.8");
+
+/*
+ * Scale is 1/gain. Value 0.125 is ALS gain x (1/8), 0.25 is
+ * ALS gain x (1/4), 1.0 = ALS gain x 1 and 2.0 is ALS gain x 2.
+ */
+static IIO_CONST_ATTR(in_illuminance_scale_available,
+				"0.125 0.25 1.0 2.0");
+
+/*
+ * Power saving modes 1/2/3/4.
+ * Products can achieve a trade-off between power savings and
+ * frequency of als latest readings available through psm.
+ */
+static IIO_CONST_ATTR(in_illuminance_psm_available,
+				"1 2 3 4");
+
+static ssize_t in_illuminance_psm_store(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf, size_t len)
+{
+	int ret;
+	unsigned int val;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (kstrtouint(buf, 0, &val))
+		return -EINVAL;
+
+	if (val < 1 || val > 4)
+		return -EINVAL;
+
+	/* update bits 1-2 */
+	val = ((val - 1) << 1);
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_PSM,
+					VEML6030_PSM, val);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't update psm value %d\n", ret);
+		return ret;
+	}
+
+	return len;
+}
+
+static ssize_t in_illuminance_psm_show(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int ret, reg;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = regmap_read(data->regmap, VEML6030_REG_ALS_PSM, &reg);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't read psm register %d\n", ret);
+		return ret;
+	}
+
+	return sprintf(buf, "%d\n", (((reg >> 1) & 0x03) + 1));
+}
+
+static IIO_DEVICE_ATTR_RW(in_illuminance_psm, 0);
+
+static struct attribute *veml6030_attributes[] = {
+	&iio_const_attr_in_illuminance_integration_time_available.dev_attr.attr,
+	&iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
+	&iio_const_attr_in_illuminance_psm_available.dev_attr.attr,
+	&iio_dev_attr_in_illuminance_psm.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group veml6030_attr_group = {
+	.attrs = veml6030_attributes,
+};
+
+/*
+ * Persistence = 1/2/4/8 x integration time
+ * Minimum time for which light readings must stay above configured
+ * threshold to assert interrupt.
+ */
+static IIO_CONST_ATTR(in_illuminance_period_available,
+				"1 2 4 8");
+
+static struct attribute *veml6030_event_attributes[] = {
+	&iio_const_attr_in_illuminance_period_available.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group veml6030_event_attr_group = {
+	.attrs = veml6030_event_attributes,
+};
+
+static int veml6030_als_pwr_on(struct veml6030_data *data)
+{
+	return regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+				 VEML6030_ALS_SD, 0);
+}
+
+static int veml6030_als_shut_down(struct veml6030_data *data)
+{
+	return regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+				 VEML6030_ALS_SD, 1);
+}
+
+static void veml6030_als_shut_down_action(void *data)
+{
+	veml6030_als_shut_down(data);
+}
+
+static const struct iio_event_spec veml6030_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_PERIOD),
+	}, {
+		.type = IIO_EV_TYPE_THRESH,
+		.dir = IIO_EV_DIR_EITHER,
+		.mask_separate = BIT(IIO_EV_INFO_ENABLE),
+	},
+};
+
+/* Channel number */
+enum veml6030_chan {
+	CH_ALS,
+	CH_WHITE,
+};
+
+static const struct iio_chan_spec veml6030_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.channel = CH_ALS,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				BIT(IIO_CHAN_INFO_PROCESSED) |
+				BIT(IIO_CHAN_INFO_INT_TIME) |
+				BIT(IIO_CHAN_INFO_SCALE),
+		.event_spec = veml6030_event_spec,
+		.num_event_specs = ARRAY_SIZE(veml6030_event_spec),
+	},
+	{
+		.type = IIO_INTENSITY,
+		.channel = CH_WHITE,
+		.modified = 1,
+		.channel2 = IIO_MOD_LIGHT_BOTH,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				BIT(IIO_CHAN_INFO_PROCESSED),
+	},
+};
+
+static const struct regmap_config veml6030_regmap_config = {
+	.name = "veml6030_regmap",
+	.reg_bits = 8,
+	.val_bits = 16,
+	.max_register = VEML6030_REG_ALS_INT,
+	.val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+static int veml6030_read_persistence(struct iio_dev *indio_dev,
+						int *val, int *val2)
+{
+	int ret, reg;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't als configuration register %d\n", ret);
+		return ret;
+	}
+
+	*val = 1 << ((reg >> 3) & 0x03);
+	*val2 = 0;
+	return IIO_VAL_INT;
+}
+
+static int veml6030_write_persistence(struct iio_dev *indio_dev,
+						int val, int val2)
+{
+	int ret;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val < 0 || val > 8 || hweight8(val) != 1 || val2)
+		return -EINVAL;
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+					VEML6030_ALS_PERS, val << 4);
+	if (ret)
+		dev_err(&data->client->dev,
+				"can't set persistence value %d\n", ret);
+
+	return ret;
+}
+
+static int veml6030_set_als_gain(struct iio_dev *indio_dev,
+						int val, int val2)
+{
+	int ret, new_gain, gain_idx;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val == 0 && val2 == 125000) {
+		new_gain = 0x1000; /* 0x02 << 11 */
+		gain_idx = 3;
+	} else if (val == 0 && val2 == 250000) {
+		new_gain = 0x1800;
+		gain_idx = 2;
+	} else if (val == 1 && val2 == 0) {
+		new_gain = 0x00;
+		gain_idx = 1;
+	} else if (val == 2 && val2 == 0) {
+		new_gain = 0x800;
+		gain_idx = 0;
+	} else {
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+					VEML6030_ALS_GAIN, new_gain);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't set als gain %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Cache currently set gain & update resolution. For every
+	 * increase in the gain to next level, resolution is halved
+	 * and vice-versa.
+	 */
+	if (data->cur_gain < gain_idx)
+		data->cur_resolution <<= gain_idx - data->cur_gain;
+	else if (data->cur_gain > gain_idx)
+		data->cur_resolution >>= data->cur_gain - gain_idx;
+
+	data->cur_gain = gain_idx;
+
+	return ret;
+}
+
+static int veml6030_get_als_gain(struct iio_dev *indio_dev,
+						int *val, int *val2)
+{
+	int ret, reg;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't als configuration register %d\n", ret);
+		return ret;
+	}
+
+	switch ((reg >> 11) & 0x03) {
+	case 0:
+		*val = 1;
+		*val2 = 0;
+		break;
+	case 1:
+		*val = 2;
+		*val2 = 0;
+		break;
+	case 2:
+		*val = 0;
+		*val2 = 125000;
+		break;
+	case 3:
+		*val = 0;
+		*val2 = 250000;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int veml6030_read_thresh(struct iio_dev *indio_dev,
+						int *val, int *val2, int dir)
+{
+	int ret, reg;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (dir == IIO_EV_DIR_RISING)
+		ret = regmap_read(data->regmap, VEML6030_REG_ALS_WH, &reg);
+	else
+		ret = regmap_read(data->regmap, VEML6030_REG_ALS_WL, &reg);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't read als threshold value %d\n", ret);
+		return ret;
+	}
+
+	*val = reg & 0xffff;
+	*val2 = 0;
+	return IIO_VAL_INT;
+}
+
+static int veml6030_write_thresh(struct iio_dev *indio_dev,
+						int val, int val2, int dir)
+{
+	int ret;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val > 0xFFFF || val < 0 || val2)
+		return -EINVAL;
+
+	if (dir == IIO_EV_DIR_RISING) {
+		ret = regmap_write(data->regmap, VEML6030_REG_ALS_WH, val);
+		if (ret)
+			dev_err(&data->client->dev,
+					"can't set high threshold %d\n", ret);
+	} else {
+		ret = regmap_write(data->regmap, VEML6030_REG_ALS_WL, val);
+		if (ret)
+			dev_err(&data->client->dev,
+					"can't set low threshold %d\n", ret);
+	}
+
+	return ret;
+}
+
+static int veml6030_get_intgrn_tm(struct iio_dev *indio_dev,
+						int *val, int *val2)
+{
+	int ret, reg;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't als configuration register %d\n", ret);
+		return ret;
+	}
+
+	switch ((reg >> 6) & 0xF) {
+	case 0:
+		*val2 = 100000;
+		break;
+	case 1:
+		*val2 = 200000;
+		break;
+	case 2:
+		*val2 = 400000;
+		break;
+	case 3:
+		*val2 = 800000;
+		break;
+	case 8:
+		*val2 = 50000;
+		break;
+	case 12:
+		*val2 = 25000;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	*val = 0;
+	return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int veml6030_set_intgrn_tm(struct iio_dev *indio_dev,
+						int val, int val2)
+{
+	int ret, new_int_time, int_idx;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (val)
+		return -EINVAL;
+
+	switch (val2) {
+	case 25000:
+		new_int_time = 0x300;
+		int_idx = 5;
+		break;
+	case 50000:
+		new_int_time = 0x200;
+		int_idx = 4;
+		break;
+	case 100000:
+		new_int_time = 0x00;
+		int_idx = 3;
+		break;
+	case 200000:
+		new_int_time = 0x40;
+		int_idx = 2;
+		break;
+	case 400000:
+		new_int_time = 0x80;
+		int_idx = 1;
+		break;
+	case 800000:
+		new_int_time = 0xC0;
+		int_idx = 0;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+					VEML6030_ALS_IT, new_int_time);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't update als integration time %d\n", ret);
+		return ret;
+	}
+
+	/*
+	 * Cache current integration time and update resolution. For every
+	 * increase in integration time to next level, resolution is halved
+	 * and vice-versa.
+	 */
+	if (data->cur_integration_time < int_idx)
+		data->cur_resolution <<= int_idx - data->cur_integration_time;
+	else if (data->cur_integration_time > int_idx)
+		data->cur_resolution >>= data->cur_integration_time - int_idx;
+
+	data->cur_integration_time = int_idx;
+
+	return ret;
+}
+
+/*
+ * Provide both raw as well as light reading in lux.
+ * light (in lux) = resolution * raw reading
+ */
+static int veml6030_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	int ret, reg;
+	struct veml6030_data *data = iio_priv(indio_dev);
+	struct regmap *regmap = data->regmap;
+	struct device *dev = &data->client->dev;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+	case IIO_CHAN_INFO_PROCESSED:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			ret = regmap_read(regmap, VEML6030_REG_ALS_DATA, &reg);
+			if (ret < 0) {
+				dev_err(dev, "can't read als data %d\n", ret);
+				return ret;
+			}
+			if (mask == IIO_CHAN_INFO_PROCESSED) {
+				*val = (reg * data->cur_resolution) / 10000;
+				*val2 = (reg * data->cur_resolution) % 10000;
+				return IIO_VAL_INT_PLUS_MICRO;
+			}
+			*val = reg;
+			*val2 = 0;
+			return IIO_VAL_INT;
+		case IIO_INTENSITY:
+			ret = regmap_read(regmap, VEML6030_REG_WH_DATA, &reg);
+			if (ret < 0) {

drivers/iio/light/veml6030.c new file +67 -0

+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_INT_TIME:
+		if (chan->type == IIO_LIGHT)
+			return veml6030_get_intgrn_tm(indio_dev, val, val2);
+		return -EINVAL;
+	case IIO_CHAN_INFO_SCALE:
+		if (chan->type == IIO_LIGHT)
+			return veml6030_get_als_gain(indio_dev, val, val2);
+		return -EINVAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6030_write_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int val, int val2, long mask)
+{
+	switch (mask) {
+	case IIO_CHAN_INFO_INT_TIME:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			return veml6030_set_intgrn_tm(indio_dev, val, val2);
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_LIGHT:
+			return veml6030_set_als_gain(indio_dev, val, val2);
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6030_read_event_val(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:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+		case IIO_EV_DIR_FALLING:
+			return veml6030_read_thresh(indio_dev, val, val2, dir);
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_EV_INFO_PERIOD:
+		return veml6030_read_persistence(indio_dev, val, val2);
+	default:
+		return -EINVAL;
+	}
+}
+
+static int veml6030_write_event_val(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)

drivers/iio/light/veml6030.c new file +144 -0

+	return -EINVAL;
+}
+
+static int veml6030_read_interrupt_config(struct iio_dev *indio_dev,
+		const struct iio_chan_spec *chan, enum iio_event_type type,
+		enum iio_event_direction dir)
+{
+	int ret, reg;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't read als conf register %d\n", ret);
+		return ret;
+	}
+
+	if (reg & VEML6030_ALS_INT_EN)
+		return 1;
+	else
+		return 0;
+}
+
+/*
+ * Sensor should not be measuring light when interrupt is configured.
+ * Therefore correct sequence to configure interrupt functionality is:
+ * shut down -> enable/disable interrupt -> power on
+ *
+ * state = 1 enables interrupt, state = 0 disables interrupt
+ */
+static int veml6030_write_interrupt_config(struct iio_dev *indio_dev,
+		const struct iio_chan_spec *chan, enum iio_event_type type,
+		enum iio_event_direction dir, int state)
+{
+	int ret;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	if (state < 0 || state > 1)
+		return -EINVAL;
+
+	ret = veml6030_als_shut_down(data);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"can't disable als to configure interrupt %d\n", ret);
+		return ret;
+	}
+
+	/* enable interrupt + power on */
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+			VEML6030_ALS_INT_EN | VEML6030_ALS_SD, state << 1);
+	if (ret)
+		dev_err(&data->client->dev,
+			"can't enable interrupt & poweron als %d\n", ret);
+
+	return ret;
+}
+
+static const struct iio_info veml6030_info = {
+	.read_raw  = veml6030_read_raw,
+	.write_raw = veml6030_write_raw,
+	.read_event_value = veml6030_read_event_val,
+	.write_event_value	= veml6030_write_event_val,
+	.read_event_config = veml6030_read_interrupt_config,
+	.write_event_config	= veml6030_write_interrupt_config,
+	.attrs = &veml6030_attr_group,
+	.event_attrs = &veml6030_event_attr_group,
+};
+
+static const struct iio_info veml6030_info_no_irq = {
+	.read_raw  = veml6030_read_raw,
+	.write_raw = veml6030_write_raw,
+	.attrs = &veml6030_attr_group,
+};
+
+static irqreturn_t veml6030_event_handler(int irq, void *private)
+{
+	int ret, reg, evtdir;
+	struct iio_dev *indio_dev = private;
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = regmap_read(data->regmap, VEML6030_REG_ALS_INT, &reg);
+	if (ret) {
+		dev_err(&data->client->dev,
+				"can't read als interrupt register %d\n", ret);
+		return IRQ_HANDLED;
+	}
+
+	/* Spurious interrupt handling */
+	if (!(reg & (VEML6030_INT_TH_HIGH | VEML6030_INT_TH_LOW)))
+		return IRQ_NONE;
+
+	if (reg & VEML6030_INT_TH_HIGH)
+		evtdir = IIO_EV_DIR_RISING;
+	else
+		evtdir = IIO_EV_DIR_FALLING;
+
+	iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY,
+					0, IIO_EV_TYPE_THRESH, evtdir),
+					iio_get_time_ns(indio_dev));
+
+	return IRQ_HANDLED;
+}
+
+/*
+ * Set ALS gain to 1/8, integration time to 100 ms, PSM to mode 2,
+ * persistence to 1 x integration time and the threshold
+ * interrupt disabled by default. First shutdown the sensor,
+ * update registers and then power on the sensor.
+ */
+static int veml6030_hw_init(struct iio_dev *indio_dev)
+{
+	int ret, val;
+	struct veml6030_data *data = iio_priv(indio_dev);
+	struct i2c_client *client = data->client;
+
+	ret = veml6030_als_shut_down(data);
+	if (ret) {
+		dev_err(&client->dev, "can't shutdown als %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(data->regmap, VEML6030_REG_ALS_CONF, 0x1001);
+	if (ret) {
+		dev_err(&client->dev, "can't setup als configs %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_PSM,
+				 VEML6030_PSM | VEML6030_PSM_EN, 0x03);
+	if (ret) {
+		dev_err(&client->dev, "can't setup default PSM %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(data->regmap, VEML6030_REG_ALS_WH, 0xFFFF);
+	if (ret) {
+		dev_err(&client->dev, "can't setup high threshold %d\n", ret);
+		return ret;
+	}
+
+	ret = regmap_write(data->regmap, VEML6030_REG_ALS_WL, 0x0000);
+	if (ret) {
+		dev_err(&client->dev, "can't setup low threshold %d\n", ret);
+		return ret;

drivers/iio/light/veml6030.c new file +58 -0

+
+	/* Clear stale interrupt status bits if any during start */
+	ret = regmap_read(data->regmap, VEML6030_REG_ALS_INT, &val);
+	if (ret < 0) {
+		dev_err(&client->dev,
+			"can't clear als interrupt status %d\n", ret);
+		return ret;
+	}
+
+	/* Cache currently active measurement parameters */
+	data->cur_gain = 3;
+	data->cur_resolution = 4608;
+	data->cur_integration_time = 3;
+
+	return ret;
+}
+
+static int veml6030_probe(struct i2c_client *client,
+			  const struct i2c_device_id *id)
+{
+	int ret;
+	struct veml6030_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+
+	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+		dev_err(&client->dev, "i2c adapter doesn't support plain i2c\n");
+		return -EOPNOTSUPP;
+	}
+
+	regmap = devm_regmap_init_i2c(client, &veml6030_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "can't setup regmap\n");
+		return PTR_ERR(regmap);
+	}
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	data = iio_priv(indio_dev);
+	i2c_set_clientdata(client, indio_dev);
+	data->client = client;
+	data->regmap = regmap;
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = "veml6030";
+	indio_dev->channels = veml6030_channels;
+	indio_dev->num_channels = ARRAY_SIZE(veml6030_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	if (client->irq) {
+		ret = devm_request_threaded_irq(&client->dev, client->irq,
+						NULL, veml6030_event_handler,
+						IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+						"veml6030", indio_dev);
+		if (ret < 0) {
+			dev_err(&client->dev,

drivers/iio/light/veml6030.c new file +69 -0

+	if (ret < 0)
+		return ret;
+
+	ret = veml6030_hw_init(indio_dev);
+	if (ret < 0)
+		return ret;
+
+	return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static int __maybe_unused veml6030_runtime_suspend(struct device *dev)
+{
+	int ret;
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = veml6030_als_shut_down(data);
+	if (ret < 0)
+		dev_err(&data->client->dev, "can't suspend als %d\n", ret);
+
+	return ret;
+}
+
+static int __maybe_unused veml6030_runtime_resume(struct device *dev)
+{
+	int ret;
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct veml6030_data *data = iio_priv(indio_dev);
+
+	ret = veml6030_als_pwr_on(data);
+	if (ret < 0)
+		dev_err(&data->client->dev, "can't resume als %d\n", ret);
+
+	return ret;
+}
+
+static const struct dev_pm_ops veml6030_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(veml6030_runtime_suspend,
+				veml6030_runtime_resume, NULL)
+};
+
+static const struct of_device_id veml6030_of_match[] = {
+	{ .compatible = "vishay,veml6030" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, veml6030_of_match);
+
+static const struct i2c_device_id veml6030_id[] = {
+	{ "veml6030", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, veml6030_id);
+
+static struct i2c_driver veml6030_driver = {
+	.driver = {
+		.name = "veml6030",
+		.of_match_table = veml6030_of_match,
+		.pm = &veml6030_pm_ops,
+	},
+	.probe = veml6030_probe,
+	.id_table = veml6030_id,
+};
+module_i2c_driver(veml6030_driver);
+
+MODULE_AUTHOR("Rishi Gupta <[email protected]>");
+MODULE_DESCRIPTION("VEML6030 Ambient Light Sensor");
+MODULE_LICENSE("GPL v2");

Quoted 7 lines · On Tue, 22 Oct 2019 09:27:15 +0530 Rishi Gupta <[email protected]> wrote:

veml6030 is an ambient light sensor from Vishay semiconductors. It has 16-bit resolution, supports both ambient light measurement and white channel which is more responsive to wider wavelength spectrum. It has flexible power saving, integration time and gain options. Communication with host is over I2C.

Signed-off-by Rishi Gupta <[email protected]>

Please avoid this complex nested replies to old patches. New version of a series should be a new thread.

It's much easier for myself or others to be sure they have the latest version than when they are interleaved like this.

I've raised ABI concerns in patch 3, so won't repeat that here

Various minor other things inline.

Jonathan

Quoted 596 lines

---
Changes in v4:
* None

Changes in v3:
* Added appnote link in topmost comments section
* Dropped 'return ret' statements wherever not needed
* Removed .scan_index from channel specifications, not needed
* If irq is not enabled, events interfaces are not exposed now
* Return IRQ_NONE for spurious interrupt
* Removed CONFIG_PM, added __maybe_unused in power routines
* Removed of_match_ptr when specifying DT device id to match
* Corrected & documented sequence in veml6030_write_interrupt_config()
* Removed veml6030_remove() & added devm_add_action_or_reset functionality
* Added support to read integration time, gain, thresholds, period
* Removed including mutex.h not needed
* Set 100 ms integration & 1/8 gain during probe for better accuracy
* Used IIO_CONST_ATTR to create sysfs entries "_available"
* Minor cosmetics like everything in lower case

Changes in v2:
* Added comma after CH_WHITE in enum veml6030_chan so it can be extended
* Removed .scan_type as driver doesn't use buffered mode
* Removed iio_device_unregister() as kernel will take care of cleaning

 drivers/iio/light/Kconfig    |  11 +
 drivers/iio/light/Makefile   |   1 +
 drivers/iio/light/veml6030.c | 903 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 915 insertions(+)
 create mode 100644 drivers/iio/light/veml6030.c

drivers/iio/light/Kconfig +11 -0

index 4a1a883..f9d27ef 100644
@@ -496,6 +496,17 @@ config VCNL4035
        To compile this driver as a module, choose M here: the
        module will be called vcnl4035.
 
+config VEML6030
+     tristate "VEML6030 ambient light sensor"
+     select REGMAP_I2C
+     depends on I2C
+     help
+       Say Y here if you want to build a driver for the Vishay VEML6030
+       ambient light sensor (ALS).
+
+       To compile this driver as a module, choose M here: the
+       module will be called veml6030.
+
 config VEML6070
      tristate "VEML6070 UV A light sensor"
      depends on I2C

drivers/iio/light/Makefile +1 -0

index 00d1f9b..5e0c40b 100644
@@ -48,6 +48,7 @@ obj-$(CONFIG_TSL4531)               += tsl4531.o
 obj-$(CONFIG_US5182D)                += us5182d.o
 obj-$(CONFIG_VCNL4000)               += vcnl4000.o
 obj-$(CONFIG_VCNL4035)               += vcnl4035.o
+obj-$(CONFIG_VEML6030)               += veml6030.o
 obj-$(CONFIG_VEML6070)               += veml6070.o
 obj-$(CONFIG_VL6180)         += vl6180.o
 obj-$(CONFIG_ZOPT2201)               += zopt2201.o

drivers/iio/light/veml6030.c new file +525 -0

new file mode 100644
index 0000000..d0d4e42
@@ -0,0 +1,903 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * VEML6030 Ambient Light Sensor
+ *
+ * Copyright (c) 2019, Rishi Gupta <[email protected]>
+ *
+ * Datasheet: https://www.vishay.com/docs/84366/veml6030.pdf
+ * Appnote-84367: https://www.vishay.com/docs/84367/designingveml6030.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/regmap.h>
+#include <linux/interrupt.h>
+#include <linux/pm_runtime.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/events.h>
+
+/* Device registers */
+#define VEML6030_REG_ALS_CONF   0x00
+#define VEML6030_REG_ALS_WH     0x01
+#define VEML6030_REG_ALS_WL     0x02
+#define VEML6030_REG_ALS_PSM    0x03
+#define VEML6030_REG_ALS_DATA   0x04
+#define VEML6030_REG_WH_DATA    0x05
+#define VEML6030_REG_ALS_INT    0x06
+
+/* Bit masks for specific functionality */
+#define VEML6030_ALS_IT       GENMASK(9, 6)
+#define VEML6030_PSM          GENMASK(2, 1)
+#define VEML6030_ALS_PERS     GENMASK(5, 4)
+#define VEML6030_ALS_GAIN     GENMASK(12, 11)
+#define VEML6030_PSM_EN       BIT(0)
+#define VEML6030_INT_TH_LOW   BIT(15)
+#define VEML6030_INT_TH_HIGH  BIT(14)
+#define VEML6030_ALS_INT_EN   BIT(1)
+#define VEML6030_ALS_SD       BIT(0)
+
+/*
+ * The resolution depends on both gain and integration time. The
+ * cur_resolution stores one of the resolution mentioned in the
+ * table during startup and gets updated whenever integration time
+ * or gain is changed.
+ *
+ * Table 'resolution and maximum detection range' in appnote 84367
+ * is visualized as a 2D array. The cur_gain stores index of gain
+ * in this table (0-3) while the cur_integration_time holds index
+ * of integration time (0-5).
+ */
+struct veml6030_data {
+     struct i2c_client *client;
+     struct regmap *regmap;
+     int cur_resolution;
+     int cur_gain;
+     int cur_integration_time;
+};
+
+/* Integration time available in seconds */
+static IIO_CONST_ATTR(in_illuminance_integration_time_available,
+                             "0.025 0.05 0.1 0.2 0.4 0.8");
+
+/*
+ * Scale is 1/gain. Value 0.125 is ALS gain x (1/8), 0.25 is
+ * ALS gain x (1/4), 1.0 = ALS gain x 1 and 2.0 is ALS gain x 2.
+ */
+static IIO_CONST_ATTR(in_illuminance_scale_available,
+                             "0.125 0.25 1.0 2.0");
+
+/*
+ * Power saving modes 1/2/3/4.
+ * Products can achieve a trade-off between power savings and
+ * frequency of als latest readings available through psm.
+ */
+static IIO_CONST_ATTR(in_illuminance_psm_available,
+                             "1 2 3 4");
+
+static ssize_t in_illuminance_psm_store(struct device *dev,
+                                             struct device_attribute *attr,
+                                             const char *buf, size_t len)
+{
+     int ret;
+     unsigned int val;
+     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     if (kstrtouint(buf, 0, &val))
+             return -EINVAL;
+
+     if (val < 1 || val > 4)
+             return -EINVAL;
+
+     /* update bits 1-2 */
+     val = ((val - 1) << 1);
+
+     ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_PSM,
+                                     VEML6030_PSM, val);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't update psm value %d\n", ret);
+             return ret;
+     }
+
+     return len;
+}
+
+static ssize_t in_illuminance_psm_show(struct device *dev,
+                             struct device_attribute *attr, char *buf)
+{
+     int ret, reg;
+     struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = regmap_read(data->regmap, VEML6030_REG_ALS_PSM, &reg);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't read psm register %d\n", ret);
+             return ret;
+     }
+
+     return sprintf(buf, "%d\n", (((reg >> 1) & 0x03) + 1));
+}
+
+static IIO_DEVICE_ATTR_RW(in_illuminance_psm, 0);
+
+static struct attribute *veml6030_attributes[] = {
+     &iio_const_attr_in_illuminance_integration_time_available.dev_attr.attr,
+     &iio_const_attr_in_illuminance_scale_available.dev_attr.attr,
+     &iio_const_attr_in_illuminance_psm_available.dev_attr.attr,
+     &iio_dev_attr_in_illuminance_psm.dev_attr.attr,
+     NULL
+};
+
+static const struct attribute_group veml6030_attr_group = {
+     .attrs = veml6030_attributes,
+};
+
+/*
+ * Persistence = 1/2/4/8 x integration time
+ * Minimum time for which light readings must stay above configured
+ * threshold to assert interrupt.
+ */
+static IIO_CONST_ATTR(in_illuminance_period_available,
+                             "1 2 4 8");
+
+static struct attribute *veml6030_event_attributes[] = {
+     &iio_const_attr_in_illuminance_period_available.dev_attr.attr,
+     NULL
+};
+
+static const struct attribute_group veml6030_event_attr_group = {
+     .attrs = veml6030_event_attributes,
+};
+
+static int veml6030_als_pwr_on(struct veml6030_data *data)
+{
+     return regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+                              VEML6030_ALS_SD, 0);
+}
+
+static int veml6030_als_shut_down(struct veml6030_data *data)
+{
+     return regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+                              VEML6030_ALS_SD, 1);
+}
+
+static void veml6030_als_shut_down_action(void *data)
+{
+     veml6030_als_shut_down(data);
+}
+
+static const struct iio_event_spec veml6030_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_PERIOD),
+     }, {
+             .type = IIO_EV_TYPE_THRESH,
+             .dir = IIO_EV_DIR_EITHER,
+             .mask_separate = BIT(IIO_EV_INFO_ENABLE),
+     },
+};
+
+/* Channel number */
+enum veml6030_chan {
+     CH_ALS,
+     CH_WHITE,
+};
+
+static const struct iio_chan_spec veml6030_channels[] = {
+     {
+             .type = IIO_LIGHT,
+             .channel = CH_ALS,
+             .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                             BIT(IIO_CHAN_INFO_PROCESSED) |
+                             BIT(IIO_CHAN_INFO_INT_TIME) |
+                             BIT(IIO_CHAN_INFO_SCALE),
+             .event_spec = veml6030_event_spec,
+             .num_event_specs = ARRAY_SIZE(veml6030_event_spec),
+     },
+     {
+             .type = IIO_INTENSITY,
+             .channel = CH_WHITE,
+             .modified = 1,
+             .channel2 = IIO_MOD_LIGHT_BOTH,
+             .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+                             BIT(IIO_CHAN_INFO_PROCESSED),
+     },
+};
+
+static const struct regmap_config veml6030_regmap_config = {
+     .name = "veml6030_regmap",
+     .reg_bits = 8,
+     .val_bits = 16,
+     .max_register = VEML6030_REG_ALS_INT,
+     .val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+static int veml6030_read_persistence(struct iio_dev *indio_dev,
+                                             int *val, int *val2)
+{
+     int ret, reg;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't als configuration register %d\n", ret);
+             return ret;
+     }
+
+     *val = 1 << ((reg >> 3) & 0x03);
+     *val2 = 0;
+     return IIO_VAL_INT;
+}
+
+static int veml6030_write_persistence(struct iio_dev *indio_dev,
+                                             int val, int val2)
+{
+     int ret;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     if (val < 0 || val > 8 || hweight8(val) != 1 || val2)
+             return -EINVAL;
+
+     ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+                                     VEML6030_ALS_PERS, val << 4);
+     if (ret)
+             dev_err(&data->client->dev,
+                             "can't set persistence value %d\n", ret);
+
+     return ret;
+}
+
+static int veml6030_set_als_gain(struct iio_dev *indio_dev,
+                                             int val, int val2)
+{
+     int ret, new_gain, gain_idx;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     if (val == 0 && val2 == 125000) {
+             new_gain = 0x1000; /* 0x02 << 11 */
+             gain_idx = 3;
+     } else if (val == 0 && val2 == 250000) {
+             new_gain = 0x1800;
+             gain_idx = 2;
+     } else if (val == 1 && val2 == 0) {
+             new_gain = 0x00;
+             gain_idx = 1;
+     } else if (val == 2 && val2 == 0) {
+             new_gain = 0x800;
+             gain_idx = 0;
+     } else {
+             return -EINVAL;
+     }
+
+     ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+                                     VEML6030_ALS_GAIN, new_gain);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't set als gain %d\n", ret);
+             return ret;
+     }
+
+     /*
+      * Cache currently set gain & update resolution. For every
+      * increase in the gain to next level, resolution is halved
+      * and vice-versa.
+      */
+     if (data->cur_gain < gain_idx)
+             data->cur_resolution <<= gain_idx - data->cur_gain;
+     else if (data->cur_gain > gain_idx)
+             data->cur_resolution >>= data->cur_gain - gain_idx;
+
+     data->cur_gain = gain_idx;
+
+     return ret;
+}
+
+static int veml6030_get_als_gain(struct iio_dev *indio_dev,
+                                             int *val, int *val2)
+{
+     int ret, reg;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't als configuration register %d\n", ret);
+             return ret;
+     }
+
+     switch ((reg >> 11) & 0x03) {
+     case 0:
+             *val = 1;
+             *val2 = 0;
+             break;
+     case 1:
+             *val = 2;
+             *val2 = 0;
+             break;
+     case 2:
+             *val = 0;
+             *val2 = 125000;
+             break;
+     case 3:
+             *val = 0;
+             *val2 = 250000;
+             break;
+     default:
+             return -EINVAL;
+     }
+
+     return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int veml6030_read_thresh(struct iio_dev *indio_dev,
+                                             int *val, int *val2, int dir)
+{
+     int ret, reg;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     if (dir == IIO_EV_DIR_RISING)
+             ret = regmap_read(data->regmap, VEML6030_REG_ALS_WH, &reg);
+     else
+             ret = regmap_read(data->regmap, VEML6030_REG_ALS_WL, &reg);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't read als threshold value %d\n", ret);
+             return ret;
+     }
+
+     *val = reg & 0xffff;
+     *val2 = 0;
+     return IIO_VAL_INT;
+}
+
+static int veml6030_write_thresh(struct iio_dev *indio_dev,
+                                             int val, int val2, int dir)
+{
+     int ret;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     if (val > 0xFFFF || val < 0 || val2)
+             return -EINVAL;
+
+     if (dir == IIO_EV_DIR_RISING) {
+             ret = regmap_write(data->regmap, VEML6030_REG_ALS_WH, val);
+             if (ret)
+                     dev_err(&data->client->dev,
+                                     "can't set high threshold %d\n", ret);
+     } else {
+             ret = regmap_write(data->regmap, VEML6030_REG_ALS_WL, val);
+             if (ret)
+                     dev_err(&data->client->dev,
+                                     "can't set low threshold %d\n", ret);
+     }
+
+     return ret;
+}
+
+static int veml6030_get_intgrn_tm(struct iio_dev *indio_dev,
+                                             int *val, int *val2)
+{
+     int ret, reg;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't als configuration register %d\n", ret);
+             return ret;
+     }
+
+     switch ((reg >> 6) & 0xF) {
+     case 0:
+             *val2 = 100000;
+             break;
+     case 1:
+             *val2 = 200000;
+             break;
+     case 2:
+             *val2 = 400000;
+             break;
+     case 3:
+             *val2 = 800000;
+             break;
+     case 8:
+             *val2 = 50000;
+             break;
+     case 12:
+             *val2 = 25000;
+             break;
+     default:
+             return -EINVAL;
+     }
+
+     *val = 0;
+     return IIO_VAL_INT_PLUS_MICRO;
+}
+
+static int veml6030_set_intgrn_tm(struct iio_dev *indio_dev,
+                                             int val, int val2)
+{
+     int ret, new_int_time, int_idx;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     if (val)
+             return -EINVAL;
+
+     switch (val2) {
+     case 25000:
+             new_int_time = 0x300;
+             int_idx = 5;
+             break;
+     case 50000:
+             new_int_time = 0x200;
+             int_idx = 4;
+             break;
+     case 100000:
+             new_int_time = 0x00;
+             int_idx = 3;
+             break;
+     case 200000:
+             new_int_time = 0x40;
+             int_idx = 2;
+             break;
+     case 400000:
+             new_int_time = 0x80;
+             int_idx = 1;
+             break;
+     case 800000:
+             new_int_time = 0xC0;
+             int_idx = 0;
+             break;
+     default:
+             return -EINVAL;
+     }
+
+     ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+                                     VEML6030_ALS_IT, new_int_time);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't update als integration time %d\n", ret);
+             return ret;
+     }
+
+     /*
+      * Cache current integration time and update resolution. For every
+      * increase in integration time to next level, resolution is halved
+      * and vice-versa.
+      */
+     if (data->cur_integration_time < int_idx)
+             data->cur_resolution <<= int_idx - data->cur_integration_time;
+     else if (data->cur_integration_time > int_idx)
+             data->cur_resolution >>= data->cur_integration_time - int_idx;
+
+     data->cur_integration_time = int_idx;
+
+     return ret;
+}
+
+/*
+ * Provide both raw as well as light reading in lux.
+ * light (in lux) = resolution * raw reading
+ */
+static int veml6030_read_raw(struct iio_dev *indio_dev,
+                         struct iio_chan_spec const *chan, int *val,
+                         int *val2, long mask)
+{
+     int ret, reg;
+     struct veml6030_data *data = iio_priv(indio_dev);
+     struct regmap *regmap = data->regmap;
+     struct device *dev = &data->client->dev;
+
+     switch (mask) {
+     case IIO_CHAN_INFO_RAW:
+     case IIO_CHAN_INFO_PROCESSED:
+             switch (chan->type) {
+             case IIO_LIGHT:
+                     ret = regmap_read(regmap, VEML6030_REG_ALS_DATA, &reg);
+                     if (ret < 0) {
+                             dev_err(dev, "can't read als data %d\n", ret);
+                             return ret;
+                     }
+                     if (mask == IIO_CHAN_INFO_PROCESSED) {
+                             *val = (reg * data->cur_resolution) / 10000;
+                             *val2 = (reg * data->cur_resolution) % 10000;
+                             return IIO_VAL_INT_PLUS_MICRO;
+                     }
+                     *val = reg;
+                     *val2 = 0;
+                     return IIO_VAL_INT;
+             case IIO_INTENSITY:
+                     ret = regmap_read(regmap, VEML6030_REG_WH_DATA, &reg);
+                     if (ret < 0) {

drivers/iio/light/veml6030.c line 535

Quoted 10 lines

drivers/iio/light/veml6030.c new file +10 -0

+                             dev_err(dev, "can't read white data %d\n", ret);
+                             return ret;
+                     }
+                     if (mask == IIO_CHAN_INFO_PROCESSED) {
+                             *val = (reg * data->cur_resolution) / 10000;
+                             *val2 = (reg * data->cur_resolution) % 10000;
+                             return IIO_VAL_INT_PLUS_MICRO;
+                     }
+                     *val = reg;
+                     *val2 = 0;

No need to set val2 if returning IIO_VAL_INT, it's not read.

Quoted 67 lines

drivers/iio/light/veml6030.c new file +67 -0

+                     return IIO_VAL_INT;
+             default:
+                     return -EINVAL;
+             }
+     case IIO_CHAN_INFO_INT_TIME:
+             if (chan->type == IIO_LIGHT)
+                     return veml6030_get_intgrn_tm(indio_dev, val, val2);
+             return -EINVAL;
+     case IIO_CHAN_INFO_SCALE:
+             if (chan->type == IIO_LIGHT)
+                     return veml6030_get_als_gain(indio_dev, val, val2);
+             return -EINVAL;
+     default:
+             return -EINVAL;
+     }
+}
+
+static int veml6030_write_raw(struct iio_dev *indio_dev,
+                             struct iio_chan_spec const *chan,
+                             int val, int val2, long mask)
+{
+     switch (mask) {
+     case IIO_CHAN_INFO_INT_TIME:
+             switch (chan->type) {
+             case IIO_LIGHT:
+                     return veml6030_set_intgrn_tm(indio_dev, val, val2);
+             default:
+                     return -EINVAL;
+             }
+     case IIO_CHAN_INFO_SCALE:
+             switch (chan->type) {
+             case IIO_LIGHT:
+                     return veml6030_set_als_gain(indio_dev, val, val2);
+             default:
+                     return -EINVAL;
+             }
+     default:
+             return -EINVAL;
+     }
+}
+
+static int veml6030_read_event_val(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:
+             switch (dir) {
+             case IIO_EV_DIR_RISING:
+             case IIO_EV_DIR_FALLING:
+                     return veml6030_read_thresh(indio_dev, val, val2, dir);
+             default:
+                     return -EINVAL;
+             }
+             break;
+     case IIO_EV_INFO_PERIOD:
+             return veml6030_read_persistence(indio_dev, val, val2);
+     default:
+             return -EINVAL;
+     }
+}
+
+static int veml6030_write_event_val(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)

drivers/iio/light/veml6030.c line 612

Quoted 10 lines

drivers/iio/light/veml6030.c new file +10 -0

+{
+     switch (info) {
+     case IIO_EV_INFO_VALUE:
+             return veml6030_write_thresh(indio_dev, val, val2, dir);
+     case IIO_EV_INFO_PERIOD:
+             return veml6030_write_persistence(indio_dev, val, val2);
+     default:
+             return -EINVAL;
+     }
+

You can't get here, so loose this final return.

Quoted 144 lines

drivers/iio/light/veml6030.c new file +144 -0

+     return -EINVAL;
+}
+
+static int veml6030_read_interrupt_config(struct iio_dev *indio_dev,
+             const struct iio_chan_spec *chan, enum iio_event_type type,
+             enum iio_event_direction dir)
+{
+     int ret, reg;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = regmap_read(data->regmap, VEML6030_REG_ALS_CONF, &reg);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't read als conf register %d\n", ret);
+             return ret;
+     }
+
+     if (reg & VEML6030_ALS_INT_EN)
+             return 1;
+     else
+             return 0;
+}
+
+/*
+ * Sensor should not be measuring light when interrupt is configured.
+ * Therefore correct sequence to configure interrupt functionality is:
+ * shut down -> enable/disable interrupt -> power on
+ *
+ * state = 1 enables interrupt, state = 0 disables interrupt
+ */
+static int veml6030_write_interrupt_config(struct iio_dev *indio_dev,
+             const struct iio_chan_spec *chan, enum iio_event_type type,
+             enum iio_event_direction dir, int state)
+{
+     int ret;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     if (state < 0 || state > 1)
+             return -EINVAL;
+
+     ret = veml6030_als_shut_down(data);
+     if (ret < 0) {
+             dev_err(&data->client->dev,
+                     "can't disable als to configure interrupt %d\n", ret);
+             return ret;
+     }
+
+     /* enable interrupt + power on */
+     ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
+                     VEML6030_ALS_INT_EN | VEML6030_ALS_SD, state << 1);
+     if (ret)
+             dev_err(&data->client->dev,
+                     "can't enable interrupt & poweron als %d\n", ret);
+
+     return ret;
+}
+
+static const struct iio_info veml6030_info = {
+     .read_raw  = veml6030_read_raw,
+     .write_raw = veml6030_write_raw,
+     .read_event_value = veml6030_read_event_val,
+     .write_event_value      = veml6030_write_event_val,
+     .read_event_config = veml6030_read_interrupt_config,
+     .write_event_config     = veml6030_write_interrupt_config,
+     .attrs = &veml6030_attr_group,
+     .event_attrs = &veml6030_event_attr_group,
+};
+
+static const struct iio_info veml6030_info_no_irq = {
+     .read_raw  = veml6030_read_raw,
+     .write_raw = veml6030_write_raw,
+     .attrs = &veml6030_attr_group,
+};
+
+static irqreturn_t veml6030_event_handler(int irq, void *private)
+{
+     int ret, reg, evtdir;
+     struct iio_dev *indio_dev = private;
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = regmap_read(data->regmap, VEML6030_REG_ALS_INT, &reg);
+     if (ret) {
+             dev_err(&data->client->dev,
+                             "can't read als interrupt register %d\n", ret);
+             return IRQ_HANDLED;
+     }
+
+     /* Spurious interrupt handling */
+     if (!(reg & (VEML6030_INT_TH_HIGH | VEML6030_INT_TH_LOW)))
+             return IRQ_NONE;
+
+     if (reg & VEML6030_INT_TH_HIGH)
+             evtdir = IIO_EV_DIR_RISING;
+     else
+             evtdir = IIO_EV_DIR_FALLING;
+
+     iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_INTENSITY,
+                                     0, IIO_EV_TYPE_THRESH, evtdir),
+                                     iio_get_time_ns(indio_dev));
+
+     return IRQ_HANDLED;
+}
+
+/*
+ * Set ALS gain to 1/8, integration time to 100 ms, PSM to mode 2,
+ * persistence to 1 x integration time and the threshold
+ * interrupt disabled by default. First shutdown the sensor,
+ * update registers and then power on the sensor.
+ */
+static int veml6030_hw_init(struct iio_dev *indio_dev)
+{
+     int ret, val;
+     struct veml6030_data *data = iio_priv(indio_dev);
+     struct i2c_client *client = data->client;
+
+     ret = veml6030_als_shut_down(data);
+     if (ret) {
+             dev_err(&client->dev, "can't shutdown als %d\n", ret);
+             return ret;
+     }
+
+     ret = regmap_write(data->regmap, VEML6030_REG_ALS_CONF, 0x1001);
+     if (ret) {
+             dev_err(&client->dev, "can't setup als configs %d\n", ret);
+             return ret;
+     }
+
+     ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_PSM,
+                              VEML6030_PSM | VEML6030_PSM_EN, 0x03);
+     if (ret) {
+             dev_err(&client->dev, "can't setup default PSM %d\n", ret);
+             return ret;
+     }
+
+     ret = regmap_write(data->regmap, VEML6030_REG_ALS_WH, 0xFFFF);
+     if (ret) {
+             dev_err(&client->dev, "can't setup high threshold %d\n", ret);
+             return ret;
+     }
+
+     ret = regmap_write(data->regmap, VEML6030_REG_ALS_WL, 0x0000);
+     if (ret) {
+             dev_err(&client->dev, "can't setup low threshold %d\n", ret);
+             return ret;

drivers/iio/light/veml6030.c line 766

Quoted 10 lines

drivers/iio/light/veml6030.c new file +10 -0

+     }
+
+     ret = veml6030_als_pwr_on(data);
+     if (ret) {
+             dev_err(&client->dev, "can't poweron als %d\n", ret);
+             return ret;
+     }
+
+     /* Wait 4 ms to let processor & oscillator start correctly */
+     usleep_range(3990, 4000);

I you need to sleep 4msecs then the smallest value needs to be 4msecs.

Quoted 64 lines

drivers/iio/light/veml6030.c new file +64 -0

+
+     /* Clear stale interrupt status bits if any during start */
+     ret = regmap_read(data->regmap, VEML6030_REG_ALS_INT, &val);
+     if (ret < 0) {
+             dev_err(&client->dev,
+                     "can't clear als interrupt status %d\n", ret);
+             return ret;
+     }
+
+     /* Cache currently active measurement parameters */
+     data->cur_gain = 3;
+     data->cur_resolution = 4608;
+     data->cur_integration_time = 3;
+
+     return ret;
+}
+
+static int veml6030_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+     int ret;
+     struct veml6030_data *data;
+     struct iio_dev *indio_dev;
+     struct regmap *regmap;
+
+     if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+             dev_err(&client->dev, "i2c adapter doesn't support plain i2c\n");
+             return -EOPNOTSUPP;
+     }
+
+     regmap = devm_regmap_init_i2c(client, &veml6030_regmap_config);
+     if (IS_ERR(regmap)) {
+             dev_err(&client->dev, "can't setup regmap\n");
+             return PTR_ERR(regmap);
+     }
+
+     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+     if (!indio_dev)
+             return -ENOMEM;
+
+     data = iio_priv(indio_dev);
+     i2c_set_clientdata(client, indio_dev);
+     data->client = client;
+     data->regmap = regmap;
+
+     indio_dev->dev.parent = &client->dev;
+     indio_dev->name = "veml6030";
+     indio_dev->channels = veml6030_channels;
+     indio_dev->num_channels = ARRAY_SIZE(veml6030_channels);
+     indio_dev->modes = INDIO_DIRECT_MODE;
+
+     if (client->irq) {
+             ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                             NULL, veml6030_event_handler,
+                                             IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                             "veml6030", indio_dev);
+             if (ret < 0) {
+                     dev_err(&client->dev,
+                                     "irq %d request failed\n", client->irq);
+                     return ret;
+             }
+             indio_dev->info = &veml6030_info;
+     } else {
+             indio_dev->info = &veml6030_info_no_irq;

drivers/iio/light/veml6030.c line 834

Quoted 4 lines

drivers/iio/light/veml6030.c new file +4 -0

+     }
+
+     ret = devm_add_action_or_reset(&client->dev,
+                                     veml6030_als_shut_down_action, data);

What is this reversing? It should be immediately after whatever that is, thus ensuring we only undo whatever we need to on failure and the ordering is correct for remove. I am guessing it should be after hw_init.

Quoted 69 lines

drivers/iio/light/veml6030.c new file +69 -0

+     if (ret < 0)
+             return ret;
+
+     ret = veml6030_hw_init(indio_dev);
+     if (ret < 0)
+             return ret;
+
+     return devm_iio_device_register(&client->dev, indio_dev);
+}
+
+static int __maybe_unused veml6030_runtime_suspend(struct device *dev)
+{
+     int ret;
+     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = veml6030_als_shut_down(data);
+     if (ret < 0)
+             dev_err(&data->client->dev, "can't suspend als %d\n", ret);
+
+     return ret;
+}
+
+static int __maybe_unused veml6030_runtime_resume(struct device *dev)
+{
+     int ret;
+     struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+     struct veml6030_data *data = iio_priv(indio_dev);
+
+     ret = veml6030_als_pwr_on(data);
+     if (ret < 0)
+             dev_err(&data->client->dev, "can't resume als %d\n", ret);
+
+     return ret;
+}
+
+static const struct dev_pm_ops veml6030_pm_ops = {
+     SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+                             pm_runtime_force_resume)
+     SET_RUNTIME_PM_OPS(veml6030_runtime_suspend,
+                             veml6030_runtime_resume, NULL)
+};
+
+static const struct of_device_id veml6030_of_match[] = {
+     { .compatible = "vishay,veml6030" },
+     { }
+};
+MODULE_DEVICE_TABLE(of, veml6030_of_match);
+
+static const struct i2c_device_id veml6030_id[] = {
+     { "veml6030", 0 },
+     { }
+};
+MODULE_DEVICE_TABLE(i2c, veml6030_id);
+
+static struct i2c_driver veml6030_driver = {
+     .driver = {
+             .name = "veml6030",
+             .of_match_table = veml6030_of_match,
+             .pm = &veml6030_pm_ops,
+     },
+     .probe = veml6030_probe,
+     .id_table = veml6030_id,
+};
+module_i2c_driver(veml6030_driver);
+
+MODULE_AUTHOR("Rishi Gupta <[email protected]>");
+MODULE_DESCRIPTION("VEML6030 Ambient Light Sensor");
+MODULE_LICENSE("GPL v2");

Thanks Jonathan, sorry for deep thread, learnt will keep in mind.

All suggested changes done except re-ordering devm_add_action_or_reset. Please see inline and suggest if I missed something.

Quoted 47 lines

Quoted 47 lines

drivers/iio/light/veml6030.c new file +47 -0

+static int veml6030_probe(struct i2c_client *client,
+                       const struct i2c_device_id *id)
+{
+     int ret;
+     struct veml6030_data *data;
+     struct iio_dev *indio_dev;
+     struct regmap *regmap;
+
+     if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
+             dev_err(&client->dev, "i2c adapter doesn't support plain i2c\n");
+             return -EOPNOTSUPP;
+     }
+
+     regmap = devm_regmap_init_i2c(client, &veml6030_regmap_config);
+     if (IS_ERR(regmap)) {
+             dev_err(&client->dev, "can't setup regmap\n");
+             return PTR_ERR(regmap);
+     }
+
+     indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+     if (!indio_dev)
+             return -ENOMEM;
+
+     data = iio_priv(indio_dev);
+     i2c_set_clientdata(client, indio_dev);
+     data->client = client;
+     data->regmap = regmap;
+
+     indio_dev->dev.parent = &client->dev;
+     indio_dev->name = "veml6030";
+     indio_dev->channels = veml6030_channels;
+     indio_dev->num_channels = ARRAY_SIZE(veml6030_channels);
+     indio_dev->modes = INDIO_DIRECT_MODE;
+
+     if (client->irq) {
+             ret = devm_request_threaded_irq(&client->dev, client->irq,
+                                             NULL, veml6030_event_handler,
+                                             IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+                                             "veml6030", indio_dev);
+             if (ret < 0) {
+                     dev_err(&client->dev,
+                                     "irq %d request failed\n", client->irq);
+                     return ret;
+             }
+             indio_dev->info = &veml6030_info;
+     } else {
+             indio_dev->info = &veml6030_info_no_irq;

Quoted 9 lines

drivers/iio/light/veml6030.c line 834

Quoted 4 lines

drivers/iio/light/veml6030.c new file +4 -0

+     }
+
+     ret = devm_add_action_or_reset(&client->dev,
+                                     veml6030_als_shut_down_action, data);  

What is this reversing? It should be immediately after whatever that is, thus ensuring we only undo whatever we need to on failure and the ordering is correct for remove. I am guessing it should be after hw_init.

This just disables active measurements (this is the only thing we need to do when failure happens).

Suppose hw initialisation succeeds but call to devm_add_action_or_reset() fails. In this case sensor will be left turned on as veml6030_als_shut_down_action() will never be executed. Therefore I kept it before veml6030_hw_init().
Does this sounds correct to you ?

Quoted 10 lines

Quoted 10 lines

drivers/iio/light/veml6030.c new file +9 -0

+     if (ret < 0)
+             return ret;
+
+     ret = veml6030_hw_init(indio_dev);
+     if (ret < 0)
+             return ret;
+
+     return devm_iio_device_register(&client->dev, indio_dev);
+}

This commit adds device tree bindings for veml6030 ambient light sensor.

Signed-off-by Rishi Gupta <[email protected]>

---
Changes in v2:
* Corrected grammatical mistake from 'is' to 'are' in description of bindings

 .../devicetree/bindings/iio/light/veml6030.yaml    | 62 ++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/light/veml6030.yaml

Documentation/devicetree/bindings/iio/light/veml6030.yaml new file +62 -0

new file mode 100644
index 0000000..969b314
@@ -0,0 +1,62 @@
+# SPDX-License-Identifier: GPL-2.0+
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/light/veml6030.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: VEML6030 Ambient Light Sensor (ALS)
+
+maintainers:
+  - Rishi Gupta <[email protected]>
+
+description: |
+  Bindings for the ambient light sensor veml6030 from Vishay
+  Semiconductors over an i2c interface.
+
+  Irrespective of whether interrupt is used or not, application
+  can get the ALS and White channel reading from IIO raw interface.
+
+  If the interrupts are used, application will receive an IIO event
+  whenever configured threshold is crossed.
+
+  Specifications about the sensor can be found at:
+    https://www.vishay.com/docs/84366/veml6030.pdf
+
+properties:
+  compatible:
+    enum:
+      - vishay,veml6030
+
+  reg:
+    description:
+      I2C address of the device. If the ADDR pin on veml6030
+      is pulled up, this address is 0x48. If the ADDR pin is
+      pulled down, this address is 0x10.
+    maxItems: 1
+
+  interrupts:
+    description:
+      interrupt mapping for IRQ. Configure with IRQ_TYPE_LEVEL_LOW.
+      Refer to interrupt-controller/interrupts.txt for generic
+      interrupt client node bindings.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        light-sensor@10 {
+                compatible = "vishay,veml6030";
+                reg = <0x10>;
+                interrupts = <12 IRQ_TYPE_LEVEL_LOW>;
+        };
+    };
+...

This commit adds device tree bindings for veml6030 ambient light sensor.

Signed-off-by Rishi Gupta <[email protected]>

---
Changes in v3:
* None

Changes in v2:
* Corrected grammatical mistake from 'is' to 'are' in description of bindings

 .../devicetree/bindings/iio/light/veml6030.yaml    | 62 ++++++++++++++++++++++
 1 file changed, 62 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/iio/light/veml6030.yaml

Documentation/devicetree/bindings/iio/light/veml6030.yaml new file +0 -0

new file mode 100644
index 0000000..969b314

Documentation/devicetree/bindings/iio/light/veml6030.yaml new file +23 -0

+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/light/veml6030.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: VEML6030 Ambient Light Sensor (ALS)
+
+maintainers:
+  - Rishi Gupta <[email protected]>
+
+description: |
+  Bindings for the ambient light sensor veml6030 from Vishay
+  Semiconductors over an i2c interface.
+
+  Irrespective of whether interrupt is used or not, application
+  can get the ALS and White channel reading from IIO raw interface.
+
+  If the interrupts are used, application will receive an IIO event
+  whenever configured threshold is crossed.
+
+  Specifications about the sensor can be found at:
+    https://www.vishay.com/docs/84366/veml6030.pdf
+

Documentation/devicetree/bindings/iio/light/veml6030.yaml new file +27 -1

+
+  interrupts:
+    description:
+      interrupt mapping for IRQ. Configure with IRQ_TYPE_LEVEL_LOW.
+      Refer to interrupt-controller/interrupts.txt for generic
+      interrupt client node bindings.
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/irq.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        light-sensor@10 {
+                compatible = "vishay,veml6030";
+                reg = <0x10>;
+                interrupts = <12 IRQ_TYPE_LEVEL_LOW>;
+        };
+    };
+...
--

2.7.4

The driver for veml6030 light sensor provides custom sysfs entries used to know parameters supported by the driver and to configure sensor like setting power saving mode and persistence etc. This commit document them.

Signed-off-by Rishi Gupta <[email protected]>

---
Changes in v2:
* Nothing has changed in this file

 .../ABI/testing/sysfs-bus-iio-light-veml6030       | 49 ++++++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/ABI/testing/sysfs-bus-iio-light-veml6030

Documentation/ABI/testing/sysfs-bus-iio-light-veml6030 new file +0 -0

new file mode 100644
index 0000000..13589c9

Documentation/ABI/testing/sysfs-bus-iio-light-veml6030 new file +31 -0

+Date:		September 2019
+KernelVersion:	5.3.1
+Contact:	Rishi Gupta <[email protected]>
+Description:
+		List of valid values available in multiples of integration time
+		for which the light intensity must be above the cutoff level
+		before interrupt is asserted. This refers to persistence values.
+
+What:		/sys/bus/iio/devices/iio:deviceX/events/in_illuminance_thresh_either_period
+Date:		September 2019
+KernelVersion:	5.3.1
+Contact:	Rishi Gupta <[email protected]>
+Description:
+		Value in multiple of integration time for which the light intensity must
+		be above the cutoff level before interrupt is asserted.
+
+What:		/sys/bus/iio/devices/iio:deviceX/events/in_illuminance_thresh_rising_value
+Date:		September 2019
+KernelVersion:	5.3.1
+Contact:	Rishi Gupta <[email protected]>
+Description:
+		Raw threshold value from 0 to 0xffffffff. An interrupt will be asserted whenever
+		light intensity is above this value.
+
+What:		/sys/bus/iio/devices/iio:deviceX/events/in_illuminance_thresh_falling_value
+Date:		September 2019
+KernelVersion:	5.3.1
+Contact:	Rishi Gupta <[email protected]>
+Description:
+		Raw threshold value from 0 to 0xffffffff. An interrupt will be asserted whenever
+		light intensity is below this value.