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From:   Parthiban Nallathambi <pn@denx.de>
To:     jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de,
        pmeerw@pmeerw.net, robh+dt@kernel.org, andy.shevchenko@gmail.com
Cc:     linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org,
        mark.rutland@arm.com, devicetree@vger.kernel.org,
        matthias.bgg@gmail.com, Parthiban Nallathambi <pn@denx.de>
Subject: [PATCH v7 1/2] iio: light: Add support for vishay vcnl4035
Date:   Wed,  7 Nov 2018 18:08:20 +0100
Message-Id: <20181107170821.1171886-1-pn@denx.de>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Add support for VCNL4035, which is capable of Ambient light
sensing (ALS) and proximity function. This patch adds support
only for ALS function

Signed-off-by: Parthiban Nallathambi <pn@denx.de>
---

Notes:
    Changelog in v7:
    - change probe and remove ordering
    - remove noidle pm call
    
    Changelog in v6:
    - Usage of devm_ for trigger probing and cleanups
    - pm_runtime re-order and exit patch corrections
    - IIO_INTENSITY to IIO_LIGHT, lux/steps are fixed at IT cycle
    lux can be calculated based on IT sensitivity
    - _CLEAR to _BOTH although measurement is only WHITE spectrum
    for traditional reasons
    
    Changelog in v5:
    - White spectrum is mesaured as "_CLEAR" intesity, so removed
    white spectrum modifier
    - Header re-ordering
    - Trigger init and de-init into separate function
    - Indentation correct and usage of dev_err in place of pr_err
    
    Changelog in v4:
    - New white light index is introduced for getting data from
    white spectrum
    - PM enable/disable is called from read_raw accordingly
    - Probe exit handling re-ordered
    
    Changelog in v3:
    - Usage of lock is not needed, removed mutex locking
    - ALS threshold and persistence configuration available
    as events and threshold events are notified to userspace
    - Usage of devm_ is re-ordered and exit handling updated
    - Complexity in timestamp calculation is removed and used
    iio_get_time_ns
    
    Changelog in v2:
    1. Fixed 0-day warning on le16_to_cpu usage
    2. Persistence value is directly mapped to datasheet's value to
    avoid confusions of usage from sysfs

 drivers/iio/light/Kconfig    |  13 +
 drivers/iio/light/Makefile   |   1 +
 drivers/iio/light/vcnl4035.c | 676 +++++++++++++++++++++++++++++++++++
 3 files changed, 690 insertions(+)
 create mode 100644 drivers/iio/light/vcnl4035.c

diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
index d66ea754ffff..36f458433480 100644
--- a/drivers/iio/light/Kconfig
+++ b/drivers/iio/light/Kconfig
@@ -460,6 +460,19 @@ config VCNL4000
 	 To compile this driver as a module, choose M here: the
 	 module will be called vcnl4000.
 
+config VCNL4035
+	tristate "VCNL4035 combined ALS and proximity sensor"
+	select IIO_TRIGGERED_BUFFER
+	select REGMAP_I2C
+	depends on I2C
+	help
+	 Say Y here if you want to build a driver for the Vishay VCNL4035,
+	 combined ambient light (ALS) and proximity sensor. Currently only ALS
+	 function is available.
+
+	 To compile this driver as a module, choose M here: the
+	 module will be called vcnl4035.
+
 config VEML6070
 	tristate "VEML6070 UV A light sensor"
 	depends on I2C
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
index 86337b114bc4..286bf3975372 100644
--- a/drivers/iio/light/Makefile
+++ b/drivers/iio/light/Makefile
@@ -45,6 +45,7 @@ obj-$(CONFIG_TSL2772)		+= tsl2772.o
 obj-$(CONFIG_TSL4531)		+= tsl4531.o
 obj-$(CONFIG_US5182D)		+= us5182d.o
 obj-$(CONFIG_VCNL4000)		+= vcnl4000.o
+obj-$(CONFIG_VCNL4035)		+= vcnl4035.o
 obj-$(CONFIG_VEML6070)		+= veml6070.o
 obj-$(CONFIG_VL6180)		+= vl6180.o
 obj-$(CONFIG_ZOPT2201)		+= zopt2201.o
diff --git a/drivers/iio/light/vcnl4035.c b/drivers/iio/light/vcnl4035.c
new file mode 100644
index 000000000000..cca4db312bd3
--- /dev/null
+++ b/drivers/iio/light/vcnl4035.c
@@ -0,0 +1,676 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * VCNL4035 Ambient Light and Proximity Sensor - 7-bit I2C slave address 0x60
+ *
+ * Copyright (c) 2018, DENX Software Engineering GmbH
+ * Author: Parthiban Nallathambi <pn@denx.de>
+ *
+ * TODO: Proximity
+ */
+#include <linux/bitops.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/events.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define VCNL4035_DRV_NAME	"vcnl4035"
+#define VCNL4035_IRQ_NAME	"vcnl4035_event"
+#define VCNL4035_REGMAP_NAME	"vcnl4035_regmap"
+
+/* Device registers */
+#define VCNL4035_ALS_CONF	0x00
+#define VCNL4035_ALS_THDH	0x01
+#define VCNL4035_ALS_THDL	0x02
+#define VCNL4035_ALS_DATA	0x0B
+#define VCNL4035_WHITE_DATA	0x0C
+#define VCNL4035_INT_FLAG	0x0D
+#define VCNL4035_DEV_ID		0x0E
+
+/* Register masks */
+#define VCNL4035_MODE_ALS_MASK		BIT(0)
+#define VCNL4035_MODE_ALS_WHITE_CHAN	BIT(8)
+#define VCNL4035_MODE_ALS_INT_MASK	BIT(1)
+#define VCNL4035_ALS_IT_MASK		GENMASK(7, 5)
+#define VCNL4035_ALS_PERS_MASK		GENMASK(3, 2)
+#define VCNL4035_INT_ALS_IF_H_MASK	BIT(12)
+#define VCNL4035_INT_ALS_IF_L_MASK	BIT(13)
+
+/* Default values */
+#define VCNL4035_MODE_ALS_ENABLE	BIT(0)
+#define VCNL4035_MODE_ALS_DISABLE	0x00
+#define VCNL4035_MODE_ALS_INT_ENABLE	BIT(1)
+#define VCNL4035_MODE_ALS_INT_DISABLE	0
+#define VCNL4035_DEV_ID_VAL		0x80
+#define VCNL4035_ALS_IT_DEFAULT		0x01
+#define VCNL4035_ALS_PERS_DEFAULT	0x00
+#define VCNL4035_ALS_THDH_DEFAULT	5000
+#define VCNL4035_ALS_THDL_DEFAULT	100
+#define VCNL4035_SLEEP_DELAY_MS		2000
+
+struct vcnl4035_data {
+	struct i2c_client *client;
+	struct regmap *regmap;
+	unsigned int als_it_val;
+	unsigned int als_persistence;
+	unsigned int als_thresh_low;
+	unsigned int als_thresh_high;
+	struct iio_trigger *drdy_trigger0;
+};
+
+static inline bool vcnl4035_is_triggered(struct vcnl4035_data *data)
+{
+	int ret;
+	int reg;
+
+	ret = regmap_read(data->regmap, VCNL4035_INT_FLAG, &reg);
+	if (ret < 0)
+		return false;
+
+	return !!(reg &
+		(VCNL4035_INT_ALS_IF_H_MASK | VCNL4035_INT_ALS_IF_L_MASK));
+}
+
+static irqreturn_t vcnl4035_drdy_irq_thread(int irq, void *private)
+{
+	struct iio_dev *indio_dev = private;
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+
+	if (vcnl4035_is_triggered(data)) {
+		iio_push_event(indio_dev, IIO_UNMOD_EVENT_CODE(IIO_LIGHT,
+							0,
+							IIO_EV_TYPE_THRESH,
+							IIO_EV_DIR_EITHER),
+				iio_get_time_ns(indio_dev));
+		iio_trigger_poll_chained(data->drdy_trigger0);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+/* Triggered buffer */
+static irqreturn_t vcnl4035_trigger_consumer_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+	u8 buffer[ALIGN(sizeof(u16), sizeof(s64)) + sizeof(s64)];
+	int ret;
+
+	ret = regmap_read(data->regmap, VCNL4035_ALS_DATA, (int *)buffer);
+	if (ret < 0) {
+		dev_err(&data->client->dev,
+			"Trigger consumer can't read from sensor.\n");
+		goto fail_read;
+	}
+	iio_push_to_buffers_with_timestamp(indio_dev, buffer,
+					iio_get_time_ns(indio_dev));
+
+fail_read:
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int vcnl4035_als_drdy_set_state(struct iio_trigger *trigger,
+					bool enable_drdy)
+{
+	struct iio_dev *indio_dev = iio_trigger_get_drvdata(trigger);
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+	int val = enable_drdy ? VCNL4035_MODE_ALS_INT_ENABLE :
+					VCNL4035_MODE_ALS_INT_DISABLE;
+
+	return regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
+				 VCNL4035_MODE_ALS_INT_MASK,
+				 val);
+}
+
+static const struct iio_trigger_ops vcnl4035_trigger_ops = {
+	.validate_device = iio_trigger_validate_own_device,
+	.set_trigger_state = vcnl4035_als_drdy_set_state,
+};
+
+static int vcnl4035_set_pm_runtime_state(struct vcnl4035_data *data, bool on)
+{
+	int ret;
+	struct device *dev = &data->client->dev;
+
+	if (on) {
+		ret = pm_runtime_get_sync(dev);
+		if (ret < 0)
+			pm_runtime_put_noidle(dev);
+	} else {
+		pm_runtime_mark_last_busy(dev);
+		ret = pm_runtime_put_autosuspend(dev);
+	}
+
+	return ret;
+}
+
+/*
+ *	Device IT	INT Time (ms)	Scale (lux/step)
+ *	000		50		0.064
+ *	001		100		0.032
+ *	010		200		0.016
+ *	100		400		0.008
+ *	101 - 111	800		0.004
+ * Values are proportional, so ALS INT is selected for input due to
+ * simplicity reason. Integration time value and scaling is
+ * calculated based on device INT value
+ *
+ * Raw value needs to be scaled using ALS steps
+ */
+static int vcnl4035_read_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan, int *val,
+			    int *val2, long mask)
+{
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+	int ret;
+	int raw_data;
+	unsigned int reg;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = vcnl4035_set_pm_runtime_state(data, true);
+		if  (ret < 0)
+			return ret;
+
+		ret = iio_device_claim_direct_mode(indio_dev);
+		if (!ret) {
+			if (chan->channel)
+				reg = VCNL4035_ALS_DATA;
+			else
+				reg = VCNL4035_WHITE_DATA;
+			ret = regmap_read(data->regmap, reg, &raw_data);
+			iio_device_release_direct_mode(indio_dev);
+			if (!ret) {
+				*val = raw_data;
+				ret = IIO_VAL_INT;
+			}
+		}
+		vcnl4035_set_pm_runtime_state(data, false);
+		return ret;
+	case IIO_CHAN_INFO_INT_TIME:
+		*val = 50;
+		if (data->als_it_val)
+			*val = data->als_it_val * 100;
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		*val = 64;
+		if (!data->als_it_val)
+			*val2 = 1000;
+		else
+			*val2 = data->als_it_val * 2 * 1000;
+		return IIO_VAL_FRACTIONAL;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int vcnl4035_write_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int val, int val2, long mask)
+{
+	int ret;
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_INT_TIME:
+		if (val <= 0 || val > 800)
+			return -EINVAL;
+
+		ret = vcnl4035_set_pm_runtime_state(data, true);
+		if  (ret < 0)
+			return ret;
+
+		ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
+					 VCNL4035_ALS_IT_MASK,
+					 val / 100);
+		if (!ret)
+			data->als_it_val = val / 100;
+
+		vcnl4035_set_pm_runtime_state(data, false);
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+/* No direct ABI for persistence and threshold, so eventing */
+static int vcnl4035_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 vcnl4035_data *data = iio_priv(indio_dev);
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		switch (dir) {
+		case IIO_EV_DIR_RISING:
+			*val = data->als_thresh_high;
+			return IIO_VAL_INT;
+		case IIO_EV_DIR_FALLING:
+			*val = data->als_thresh_low;
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+		break;
+	case IIO_EV_INFO_PERIOD:
+		*val = data->als_persistence;
+		return IIO_VAL_INT;
+	default:
+		return -EINVAL;
+	}
+
+}
+
+static int vcnl4035_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 vcnl4035_data *data = iio_priv(indio_dev);
+	int ret;
+
+	switch (info) {
+	case IIO_EV_INFO_VALUE:
+		/* 16 bit threshold range 0 - 65535 */
+		if (val < 0 || val > 65535)
+			return -EINVAL;
+		if (dir == IIO_EV_DIR_RISING) {
+			if (val < data->als_thresh_low)
+				return -EINVAL;
+			ret = regmap_write(data->regmap, VCNL4035_ALS_THDH,
+					   val);
+			if (ret)
+				return ret;
+			data->als_thresh_high = val;
+		} else {
+			if (val > data->als_thresh_high)
+				return -EINVAL;
+			ret = regmap_write(data->regmap, VCNL4035_ALS_THDL,
+					   val);
+			if (ret)
+				return ret;
+			data->als_thresh_low = val;
+		}
+		return ret;
+	case IIO_EV_INFO_PERIOD:
+		/* allow only 1 2 4 8 as persistence value */
+		if (val < 0 || val > 8 || hweight8(val) != 1)
+			return -EINVAL;
+		ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
+					 VCNL4035_ALS_PERS_MASK, val);
+		if (!ret)
+			data->als_persistence = val;
+		return ret;
+	default:
+		return -EINVAL;
+	}
+}
+
+static IIO_CONST_ATTR_INT_TIME_AVAIL("50 100 200 400 800");
+
+static struct attribute *vcnl4035_attributes[] = {
+	&iio_const_attr_integration_time_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group vcnl4035_attribute_group = {
+	.attrs = vcnl4035_attributes,
+};
+
+static const struct iio_info vcnl4035_info = {
+	.read_raw		= vcnl4035_read_raw,
+	.write_raw		= vcnl4035_write_raw,
+	.read_event_value	= vcnl4035_read_thresh,
+	.write_event_value	= vcnl4035_write_thresh,
+	.attrs			= &vcnl4035_attribute_group,
+};
+
+static const struct iio_event_spec vcnl4035_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),
+	},
+};
+
+enum vcnl4035_scan_index_order {
+	VCNL4035_CHAN_INDEX_LIGHT,
+	VCNL4035_CHAN_INDEX_WHITE_LED,
+};
+
+static const struct iio_buffer_setup_ops iio_triggered_buffer_setup_ops = {
+	.validate_scan_mask = &iio_validate_scan_mask_onehot,
+};
+
+static const struct iio_chan_spec vcnl4035_channels[] = {
+	{
+		.type = IIO_LIGHT,
+		.channel = 0,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+				BIT(IIO_CHAN_INFO_INT_TIME) |
+				BIT(IIO_CHAN_INFO_SCALE),
+		.event_spec = vcnl4035_event_spec,
+		.num_event_specs = ARRAY_SIZE(vcnl4035_event_spec),
+		.scan_index = VCNL4035_CHAN_INDEX_LIGHT,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
+	},
+	{
+		.type = IIO_INTENSITY,
+		.channel = 1,
+		.modified = 1,
+		.channel2 = IIO_MOD_LIGHT_BOTH,
+		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+		.scan_index = VCNL4035_CHAN_INDEX_WHITE_LED,
+		.scan_type = {
+			.sign = 'u',
+			.realbits = 16,
+			.storagebits = 16,
+			.endianness = IIO_LE,
+		},
+	},
+};
+
+static int vcnl4035_set_als_power_state(struct vcnl4035_data *data, u8 status)
+{
+	return regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
+					VCNL4035_MODE_ALS_MASK,
+					status);
+}
+
+static int vcnl4035_init(struct vcnl4035_data *data)
+{
+	int ret;
+	int id;
+
+	ret = regmap_read(data->regmap, VCNL4035_DEV_ID, &id);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "Failed to read DEV_ID register\n");
+		return ret;
+	}
+
+	if (id != VCNL4035_DEV_ID_VAL) {
+		dev_err(&data->client->dev, "Wrong id, got %x, expected %x\n",
+			id, VCNL4035_DEV_ID_VAL);
+		return -ENODEV;
+	}
+
+	ret = vcnl4035_set_als_power_state(data, VCNL4035_MODE_ALS_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	/* ALS white channel enable */
+	ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
+				 VCNL4035_MODE_ALS_WHITE_CHAN,
+				 1);
+	if (ret) {
+		dev_err(&data->client->dev, "set white channel enable %d\n",
+			ret);
+		return ret;
+	}
+
+	/* set default integration time - 100 ms for ALS */
+	ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
+				 VCNL4035_ALS_IT_MASK,
+				 VCNL4035_ALS_IT_DEFAULT);
+	if (ret) {
+		dev_err(&data->client->dev, "set default ALS IT returned %d\n",
+			ret);
+		return ret;
+	}
+	data->als_it_val = VCNL4035_ALS_IT_DEFAULT;
+
+	/* set default persistence time - 1 for ALS */
+	ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
+				 VCNL4035_ALS_PERS_MASK,
+				 VCNL4035_ALS_PERS_DEFAULT);
+	if (ret) {
+		dev_err(&data->client->dev, "set default PERS returned %d\n",
+			ret);
+		return ret;
+	}
+	data->als_persistence = VCNL4035_ALS_PERS_DEFAULT;
+
+	/* set default HIGH threshold for ALS */
+	ret = regmap_write(data->regmap, VCNL4035_ALS_THDH,
+				VCNL4035_ALS_THDH_DEFAULT);
+	if (ret) {
+		dev_err(&data->client->dev, "set default THDH returned %d\n",
+			ret);
+		return ret;
+	}
+	data->als_thresh_high = VCNL4035_ALS_THDH_DEFAULT;
+
+	/* set default LOW threshold for ALS */
+	ret = regmap_write(data->regmap, VCNL4035_ALS_THDL,
+				VCNL4035_ALS_THDL_DEFAULT);
+	if (ret) {
+		dev_err(&data->client->dev, "set default THDL returned %d\n",
+			ret);
+		return ret;
+	}
+	data->als_thresh_low = VCNL4035_ALS_THDL_DEFAULT;
+
+	return 0;
+}
+
+static bool vcnl4035_is_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case VCNL4035_ALS_CONF:
+	case VCNL4035_DEV_ID:
+		return false;
+	default:
+		return true;
+	}
+}
+
+static const struct regmap_config vcnl4035_regmap_config = {
+	.name		= VCNL4035_REGMAP_NAME,
+	.reg_bits	= 8,
+	.val_bits	= 16,
+	.max_register	= VCNL4035_DEV_ID,
+	.cache_type	= REGCACHE_RBTREE,
+	.volatile_reg	= vcnl4035_is_volatile_reg,
+	.val_format_endian = REGMAP_ENDIAN_LITTLE,
+};
+
+static int vcnl4035_probe_trigger(struct iio_dev *indio_dev)
+{
+	int ret;
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+
+	data->drdy_trigger0 = devm_iio_trigger_alloc(
+			indio_dev->dev.parent,
+			"%s-dev%d", indio_dev->name, indio_dev->id);
+	if (!data->drdy_trigger0)
+		return -ENOMEM;
+
+	data->drdy_trigger0->dev.parent = indio_dev->dev.parent;
+	data->drdy_trigger0->ops = &vcnl4035_trigger_ops;
+	iio_trigger_set_drvdata(data->drdy_trigger0, indio_dev);
+	ret = devm_iio_trigger_register(indio_dev->dev.parent,
+					data->drdy_trigger0);
+	if (ret) {
+		dev_err(&data->client->dev, "iio trigger register failed\n");
+		return ret;
+	}
+
+	/* Trigger setup */
+	ret = devm_iio_triggered_buffer_setup(indio_dev->dev.parent, indio_dev,
+					NULL, vcnl4035_trigger_consumer_handler,
+					&iio_triggered_buffer_setup_ops);
+	if (ret < 0) {
+		dev_err(&data->client->dev, "iio triggered buffer setup failed\n");
+		return ret;
+	}
+
+	/* IRQ to trigger mapping */
+	ret = devm_request_threaded_irq(&data->client->dev, data->client->irq,
+			NULL, vcnl4035_drdy_irq_thread,
+			IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+			VCNL4035_IRQ_NAME, indio_dev);
+	if (ret < 0)
+		dev_err(&data->client->dev, "request irq %d for trigger0 failed\n",
+				data->client->irq);
+	return ret;
+}
+
+static int vcnl4035_probe(struct i2c_client *client,
+				const struct i2c_device_id *id)
+{
+	struct vcnl4035_data *data;
+	struct iio_dev *indio_dev;
+	struct regmap *regmap;
+	int ret;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	regmap = devm_regmap_init_i2c(client, &vcnl4035_regmap_config);
+	if (IS_ERR(regmap)) {
+		dev_err(&client->dev, "regmap_init failed!\n");
+		return PTR_ERR(regmap);
+	}
+
+	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->info = &vcnl4035_info;
+	indio_dev->name = VCNL4035_DRV_NAME;
+	indio_dev->channels = vcnl4035_channels;
+	indio_dev->num_channels = ARRAY_SIZE(vcnl4035_channels);
+	indio_dev->modes = INDIO_DIRECT_MODE;
+
+	ret = vcnl4035_init(data);
+	if (ret < 0) {
+		dev_err(&client->dev, "vcnl4035 chip init failed\n");
+		return ret;
+	}
+
+	if (client->irq > 0) {
+		ret = vcnl4035_probe_trigger(indio_dev);
+		if (ret < 0) {
+			dev_err(&client->dev, "vcnl4035 unable init trigger\n");
+			goto fail_poweroff;
+		}
+	}
+
+	ret = pm_runtime_set_active(&client->dev);
+	if (ret < 0)
+		goto fail_poweroff;
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0)
+		goto fail_poweroff;
+
+	pm_runtime_enable(&client->dev);
+	pm_runtime_set_autosuspend_delay(&client->dev, VCNL4035_SLEEP_DELAY_MS);
+	pm_runtime_use_autosuspend(&client->dev);
+
+	return 0;
+
+fail_poweroff:
+	vcnl4035_set_als_power_state(data, VCNL4035_MODE_ALS_DISABLE);
+	return ret;
+}
+
+static int vcnl4035_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+
+	pm_runtime_dont_use_autosuspend(&client->dev);
+	pm_runtime_disable(&client->dev);
+	iio_device_unregister(indio_dev);
+	pm_runtime_set_suspended(&client->dev);
+
+	return vcnl4035_set_als_power_state(iio_priv(indio_dev),
+					VCNL4035_MODE_ALS_DISABLE);
+}
+
+static int __maybe_unused vcnl4035_runtime_suspend(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+	int ret;
+
+	ret = vcnl4035_set_als_power_state(data, VCNL4035_MODE_ALS_DISABLE);
+	regcache_mark_dirty(data->regmap);
+
+	return ret;
+}
+
+static int __maybe_unused vcnl4035_runtime_resume(struct device *dev)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
+	struct vcnl4035_data *data = iio_priv(indio_dev);
+	int ret;
+
+	regcache_sync(data->regmap);
+	ret = vcnl4035_set_als_power_state(data, VCNL4035_MODE_ALS_ENABLE);
+	if (ret < 0)
+		return ret;
+
+	/* wait for 1 ALS integration cycle */
+	msleep(data->als_it_val * 100);
+
+	return 0;
+}
+
+static const struct dev_pm_ops vcnl4035_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+				pm_runtime_force_resume)
+	SET_RUNTIME_PM_OPS(vcnl4035_runtime_suspend,
+			   vcnl4035_runtime_resume, NULL)
+};
+
+static const struct of_device_id vcnl4035_of_match[] = {
+	{ .compatible = "vishay,vcnl4035", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, vcnl4035_of_match);
+
+static struct i2c_driver vcnl4035_driver = {
+	.driver = {
+		.name   = VCNL4035_DRV_NAME,
+		.pm	= &vcnl4035_pm_ops,
+		.of_match_table = vcnl4035_of_match,
+	},
+	.probe  = vcnl4035_probe,
+	.remove	= vcnl4035_remove,
+};
+
+module_i2c_driver(vcnl4035_driver);
+
+MODULE_AUTHOR("Parthiban Nallathambi <pn@denx.de>");
+MODULE_DESCRIPTION("VCNL4035 Ambient Light Sensor driver");
+MODULE_LICENSE("GPL v2");
-- 
2.17.2