Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Sat, 30 Jun 2018 11:51:42 +0200 (CEST)
From:   Peter Meerwald-Stadler <pmeerw@pmeerw.net>
To:     Parthiban Nallathambi <pn@denx.de>
cc:     jic23@kernel.org, knaack.h@gmx.de, lars@metafoo.de,
        robh+dt@kernel.org, linux-iio@vger.kernel.org,
        linux-kernel@vger.kernel.org, mark.rutland@arm.com,
        devicetree@vger.kernel.org, matthias.bgg@gmail.com, wd@denx.de,
        sbabic@denx.de, hs@denx.de
Subject: Re: [PATCH v2 1/2] iio: light: Add support for vishay vcnl4035
In-Reply-To: <20180629153802.1639514-1-pn@denx.de>
Message-ID: <alpine.DEB.2.21.1806301131230.15970@vps.pmeerw.net>
References: <20180628123021.1628338-1-pn@denx.de> <20180629153802.1639514-1-pn@denx.de>
User-Agent: Alpine 2.21 (DEB 202 2017-01-01)
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
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

comments below

a lot of effort is in getting a timestamp; is it worth it for ALS 
measurement? also the implementation is quite involved, what is the idea?
 
> Signed-off-by: Parthiban Nallathambi <pn@denx.de>
> ---
> 
> Changelog since v1:
> 
> 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    |  12 +
>  drivers/iio/light/Makefile   |   1 +
>  drivers/iio/light/vcnl4035.c | 682 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 695 insertions(+)
>  create mode 100644 drivers/iio/light/vcnl4035.c
> 
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index c7ef8d1862d6..b7069a4c28a2 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -447,6 +447,18 @@ 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 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 80943af5d627..dce98511a59b 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -44,6 +44,7 @@ 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..45eccb462ed0
> --- /dev/null
> +++ b/drivers/iio/light/vcnl4035.c
> @@ -0,0 +1,682 @@
> +// 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/module.h>
> +#include <linux/i2c.h>
> +#include <linux/regmap.h>
> +#include <linux/pm_runtime.h>
> +
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/buffer.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_INT_FLAG	0x0D

there seems to be a tab before VCNL4035_INT_FLAG, should be space

> +#define VCNL4035_DEV_ID		0x0E
> +
> +/* Register masks */
> +#define VCNL4035_MODE_ALS_MASK		BIT(0)
> +#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	0x00
> +#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;
> +	/* protect device settings persistence, integration time, threshold */
> +	struct mutex lock;
> +	unsigned int als_it_val;
> +	unsigned int als_persistence:4;
> +	unsigned int als_thresh_low;
> +	unsigned int als_thresh_high;
> +	struct iio_trigger *drdy_trigger0;
> +	s64 irq_timestamp;
> +};
> +
> +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;
> +	if (reg & (VCNL4035_INT_ALS_IF_H_MASK | VCNL4035_INT_ALS_IF_L_MASK))
> +		return true;
> +	else
> +		return false;
> +}
> +
> +static irqreturn_t vcnl4035_drdy_irq_handler(int irq, void *private)
> +{
> +	struct iio_dev *indio_dev = private;
> +	struct vcnl4035_data *data = iio_priv(indio_dev);
> +
> +	data->irq_timestamp = iio_get_time_ns(indio_dev);
> +	return IRQ_WAKE_THREAD;
> +}
> +
> +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_trigger_poll_chained(data->drdy_trigger0);
> +		return IRQ_HANDLED;
> +	}
> +
> +	return IRQ_NONE;
> +}
> +
> +/* Triggered buffer */
> +static irqreturn_t vcnl4035_trigger_consumer_store_time(int irq, void *p)
> +{
> +	struct iio_poll_func *pf = p;
> +	struct iio_dev *indio_dev = pf->indio_dev;
> +
> +	if (!iio_trigger_using_own(indio_dev))
> +		pf->timestamp = iio_get_time_ns(indio_dev);
> +
> +	return IRQ_WAKE_THREAD;
> +}
> +
> +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);
> +	int als_data;
> +	int ret;
> +
> +	if (iio_trigger_using_own(indio_dev) && data->irq_timestamp) {
> +		pf->timestamp = data->irq_timestamp;
> +		data->irq_timestamp = 0;
> +	}
> +
> +	if (!pf->timestamp)
> +		pf->timestamp = iio_get_time_ns(indio_dev);
> +
> +	mutex_lock(&data->lock);

what is the purpose of the lock?
the comment in vcnl4035_data doesn't mention it either

> +	ret = regmap_read(data->regmap, VCNL4035_ALS_DATA, &als_data);
> +	mutex_unlock(&data->lock);
> +	if (!ret)
> +		iio_push_to_buffers_with_timestamp(indio_dev,
> +						   &als_data,

als_data needs to be large enough to hold the timestamp, see documentation 
of iio_push_to_buffers_with_timestamp()

> +						   pf->timestamp);
> +	else
> +		dev_err(&data->client->dev,
> +			"Trigger consumer can't read from sensor.\n");
> +	pf->timestamp = 0;
> +
> +	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;
> +	int ret;
> +
> +	ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
> +				 VCNL4035_MODE_ALS_INT_MASK,
> +				 val);
> +	if (ret)
> +		dev_err(&data->client->dev, "%s failed\n", __func__);
> +
> +	return ret;
> +}
> +
> +static const struct iio_trigger_ops vcnl4035_trigger_ops = {
> +	.set_trigger_state = vcnl4035_als_drdy_set_state,
> +};
> +
> +/*
> + *	Device IT	INT Time(ms)	Scale (lux/step)

maybe space before (ms)?

> + *	000		50		0.064
> + *	001		100		0.032
> + *	010		200		0.016
> + *	100		400		0.008
> + *	101 - 111	800		0.004
> + * Values are proportial, so ALS INT is selected for input due to

proportional

> + * simplicity reason. Integration time value and scaling is
> + * calculated based on device INT value
> + *
> + * Raw value needs to be scaled using ALS STEPS

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 busy;

needed? can 'ret' be used?

> +	int raw_data;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_RAW:
> +		busy = iio_device_claim_direct_mode(indio_dev);
> +		if (busy)
> +			return -EBUSY;
> +
> +		ret = regmap_read(data->regmap, VCNL4035_ALS_DATA, &raw_data);
> +		iio_device_release_direct_mode(indio_dev);
> +		if (ret < 0)
> +			return ret;
> +
> +		*val = raw_data;
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_INT_TIME:
> +		mutex_lock(&data->lock);
> +		*val = data->als_it_val * 100;
> +		if (!*val)

maybe check data->als_it_val and then set *val accordingly as done below

> +			*val = 50;
> +		mutex_unlock(&data->lock);
> +		return IIO_VAL_INT;
> +	case IIO_CHAN_INFO_SCALE:
> +		mutex_lock(&data->lock);
> +		*val = 64;
> +		if (!data->als_it_val)
> +			*val2 = 1000;
> +		else
> +			*val2 = data->als_it_val * 2 * 1000;
> +		mutex_unlock(&data->lock);
> +		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;
> +		mutex_lock(&data->lock);
> +		ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
> +					 VCNL4035_ALS_IT_MASK,
> +					 val / 100);
> +		if (!ret)
> +			data->als_it_val = val / 100;
> +		mutex_unlock(&data->lock);
> +		break;

return ret;
directly here

> +	default:
> +		return -EINVAL;
> +	}
> +	return ret;
> +}
> +
> +/* 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:
> +			mutex_lock(&data->lock);
> +			*val = data->als_thresh_high;
> +			mutex_unlock(&data->lock);
> +			break;
> +		case IIO_EV_DIR_FALLING:
> +			mutex_lock(&data->lock);
> +			*val = data->als_thresh_low;
> +			mutex_unlock(&data->lock);
> +			break;
> +		default:
> +			return -EINVAL;
> +		}
> +		break;
> +	case IIO_EV_INFO_PERIOD:
> +		mutex_lock(&data->lock);
> +		*val = data->als_persistence;
> +		mutex_unlock(&data->lock);
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return IIO_VAL_INT;

move it up, instead of the 
break;

> +}
> +
> +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 */
> +		if (val < 0 || val > 65535)
> +			return -EINVAL;
> +		if (dir == IIO_EV_DIR_RISING) {
> +			if (val < data->als_thresh_low)
> +				return -EINVAL;
> +			mutex_lock(&data->lock);
> +			ret = regmap_write(data->regmap, VCNL4035_ALS_THDH,
> +					   val);

isn't the purpose of the lock to have 
data->als_thresh_high = val;
in the same critical section?

here and similarly below

> +			mutex_unlock(&data->lock);
> +			if (ret)
> +				return ret;
> +			data->als_thresh_high = val;
> +		} else {
> +			if (val > data->als_thresh_high)
> +				return -EINVAL;
> +			mutex_lock(&data->lock);
> +			ret = regmap_write(data->regmap, VCNL4035_ALS_THDL,
> +					   val);
> +			mutex_unlock(&data->lock);
> +			if (ret)
> +				return ret;
> +			data->als_thresh_low = val;
> +		}
> +		break;
> +	case IIO_EV_INFO_PERIOD:
> +		/* allow only 1 2 4 8 as persistence value */
> +		if (val < 0 || val > 8 || (__sw_hweight8(val) != 1))

parenthesis around last condition not needed

> +			return -EINVAL;
> +		mutex_lock(&data->lock);
> +		ret = regmap_update_bits(data->regmap, VCNL4035_ALS_CONF,
> +					 VCNL4035_ALS_PERS_MASK, val);
> +		mutex_unlock(&data->lock);
> +		if (ret)
> +			return ret;
> +		data->als_persistence = val;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +	return 0;
> +}
> +
> +static IIO_CONST_ATTR(als_available_integration_time, "50 100 200 400 800");
> +static IIO_CONST_ATTR(als_available_persistence, "1 2 4 8");
> +static IIO_CONST_ATTR(als_available_threshold_range, "0 65535");
> +
> +static struct attribute *vcnl4035_attributes[] = {
> +	&iio_const_attr_als_available_integration_time.dev_attr.attr,
> +	&iio_const_attr_als_available_threshold_range.dev_attr.attr,
> +	&iio_const_attr_als_available_persistence.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,
> +};
> +
> +enum vcnl4035_scan_index_order {
> +	VCNL4035_CHAN_INDEX_LIGHT,
> +};
> +
> +static const unsigned long vcnl4035_available_scan_masks[] = {
> +	BIT(VCNL4035_CHAN_INDEX_LIGHT), 0

I'd put 0 in a separate line so that it can be extended with a single line 
patch (extreme nitpick)

> +};
> +
> +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),
> +	},
> +};
> +
> +static const struct iio_chan_spec vcnl4035_channels[] = {
> +	{
> +		.type = IIO_INTENSITY,
> +		.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,
> +		},
> +	},
> +};
> +
> +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;
> +	}
> +
> +#ifndef CONFIG_PM
> +	ret = vcnl4035_set_als_power_state(data, VCNL4035_MODE_ALS_ENABLE);
> +	if (ret < 0)
> +		return ret;
> +#endif
> +	/* 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) {
> +		pr_err("regmap_update_bits 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) {
> +		pr_err("regmap_update_bits 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) {
> +		pr_err("regmap_write 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) {
> +		pr_err("regmap_write 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(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;
> +	mutex_init(&data->lock);
> +
> +	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;
> +	}
> +
> +	ret = pm_runtime_set_active(&client->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);
> +
> +	if (client->irq) {
> +		data->drdy_trigger0 = devm_iio_trigger_alloc(
> +			indio_dev->dev.parent,
> +			"%s-dev%d", indio_dev->name, indio_dev->id);
> +		if (!data->drdy_trigger0) {
> +			ret = -ENOMEM;
> +			goto fail_pm_disable;
> +		}
> +		data->drdy_trigger0->dev.parent = indio_dev->dev.parent;
> +		data->drdy_trigger0->ops = &vcnl4035_trigger_ops;
> +		indio_dev->available_scan_masks = vcnl4035_available_scan_masks;
> +		iio_trigger_set_drvdata(data->drdy_trigger0, indio_dev);
> +
> +		/* IRQ to trigger mapping */
> +		ret = devm_request_threaded_irq(&client->dev, client->irq,
> +			vcnl4035_drdy_irq_handler, vcnl4035_drdy_irq_thread,
> +			IRQF_TRIGGER_LOW | IRQF_ONESHOT,
> +			VCNL4035_IRQ_NAME, indio_dev);
> +		if (ret < 0) {
> +			dev_err(&client->dev, "request irq %d for trigger0 failed\n",
> +				client->irq);
> +			goto fail_pm_disable;
> +			}
> +
> +		ret = devm_iio_trigger_register(indio_dev->dev.parent,
> +						data->drdy_trigger0);
> +		if (ret) {
> +			dev_err(&client->dev, "iio trigger register failed\n");
> +			goto fail_pm_disable;
> +		}
> +
> +		/* Trigger setup */
> +		ret = devm_iio_triggered_buffer_setup(indio_dev->dev.parent,
> +			indio_dev,
> +			vcnl4035_trigger_consumer_store_time,
> +			vcnl4035_trigger_consumer_handler,
> +			NULL);
> +		if (ret < 0) {
> +			dev_err(&client->dev, "iio triggered buffer setup failed\n");
> +			goto fail_pm_disable;
> +		}
> +	}
> +
> +	ret = iio_device_register(indio_dev);
> +	if (ret)
> +		goto fail_pm_disable;
> +	dev_info(&client->dev, "%s Ambient light/proximity sensor\n",

no need for this logging

> +						VCNL4035_DRV_NAME);
> +	return 0;
> +
> +fail_pm_disable:
> +	pm_runtime_disable(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);
> +	pm_runtime_put_noidle(&client->dev);
> +fail_poweroff:
> +	return vcnl4035_set_als_power_state(data, VCNL4035_MODE_ALS_DISABLE);

I think we want to return the 'ret' value indicating the original failure, 
not the return value of vcnl4035_set_als_power_state() which is likely success

> +}
> +
> +static int vcnl4035_remove(struct i2c_client *client)
> +{
> +	struct iio_dev *indio_dev = i2c_get_clientdata(client);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	pm_runtime_disable(&client->dev);
> +	pm_runtime_set_suspended(&client->dev);
> +	pm_runtime_put_noidle(&client->dev);
> +
> +	return vcnl4035_set_als_power_state(iio_priv(indio_dev),
> +					VCNL4035_MODE_ALS_DISABLE);
> +}
> +
> +#ifdef CONFIG_PM
> +static int 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;
> +
> +	mutex_lock(&data->lock);
> +	ret = vcnl4035_set_als_power_state(data, VCNL4035_MODE_ALS_DISABLE);
> +	regcache_mark_dirty(data->regmap);
> +	mutex_unlock(&data->lock);
> +
> +	return ret;
> +}
> +
> +static int 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;
> +}
> +#endif
> +
> +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 const struct i2c_device_id vcnl4035_id[] = {
> +	{ "vcnl4035", 0 },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, vcnl4035_id);
> +
> +static struct i2c_driver vcnl4035_driver = {
> +	.driver = {
> +		.name   = VCNL4035_DRV_NAME,
> +		.pm	= &vcnl4035_pm_ops,
> +		.of_match_table = of_match_ptr(vcnl4035_of_match),
> +	},
> +	.probe  = vcnl4035_probe,
> +	.remove	= vcnl4035_remove,
> +	.id_table = vcnl4035_id,
> +};
> +
> +module_i2c_driver(vcnl4035_driver);
> +
> +MODULE_AUTHOR("Parthiban Nallathambi <pn@denx.de>");
> +MODULE_DESCRIPTION("VCNL4035 Ambient Light Sensor driver");
> +MODULE_LICENSE("GPL v2");
> 

-- 

Peter Meerwald-Stadler
Mobile: +43 664 24 44 418