Re: [PATCH v6 1/2] iio: light: Add support for vishay vcnl4035

[Jonathan Cameron]

On Tue,  7 Aug 2018 12:27:03 +0200
Parthiban Nallathambi <pn@xxxxxxx> wrote:

> 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@xxxxxxx>
> 
Changelog should be below the --- as we don't want it in the final
git commit log.

> 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
> 
> 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 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 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 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

My main issue remaining in here is with the ordering in probe and
remove.  It becomes very messy and unclear once runtime_pm is
present.  I've note how I think that can be cleaned up though
such that the remove is the obvious unwind of the probe.

Unless I missing something (more than possible on a Sunday evening after
a nice dinner :) you aren't actually stopping the device from auto suspending
when running in buffered mode.

Jonathan

> ---
>  drivers/iio/light/Kconfig    |  12 +
>  drivers/iio/light/Makefile   |   1 +
>  drivers/iio/light/vcnl4035.c | 686 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 699 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..e9f471d93a15
> --- /dev/null
> +++ b/drivers/iio/light/vcnl4035.c
> @@ -0,0 +1,686 @@
> +// 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@xxxxxxx>
> + *
Nitpick. One blank line is plenty here.

> + *
> + * 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:4;

the :4 seems rather pointless. I'd drop it.

> +	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)
> +				data->als_thresh_high = val;
It is a matter of personal taste (and a question of just how much
time you spend reviewing code) but I much prefer this inverted
if (ret)
	return ret;

data->als_thresh_high = val;

return ret;
Takes one more line but means all error cases are handled the same way
by being the if case rather than having a mixture.

There are more complex cases with unwinding to do that are less obvious
but here it is easy.

> +		} else {
> +			if (val > data->als_thresh_high)
> +				return -EINVAL;
> +			ret = regmap_write(data->regmap, VCNL4035_ALS_THDL,
> +					   val);
> +			if (!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 || __sw_hweight8(val) != 1)

hweight8 not the specific implementation of it.

> +			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 unsigned long vcnl4035_available_scan_masks[] = {
> +	BIT(VCNL4035_CHAN_INDEX_LIGHT),
> +	BIT(VCNL4035_CHAN_INDEX_WHITE_LED),
> +	0
For this case we have the validate_scan_mask_onehot function.
(it's a very common case).

> +};
> +
> +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_LIGHT,

If it isn't measuring illuminance it should be IIO_INTENSITY.

Light is reserved for illuminance channels.

> +		.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,
> +					NULL);
> +	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;
Drop the return ret out of the brackets. It will be 0 or an error so that is equivalent.
> +	}
> +
> +	return 0;
> +}
> +
> +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 = iio_device_register(indio_dev);
> +	if (ret)
> +		goto fail_poweroff;
> +
> +	ret = pm_runtime_set_active(&client->dev);
> +	if (ret < 0)
> +		goto fail_unregister;
> +
> +	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_unregister:
> +	iio_device_unregister(indio_dev);
> +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);
> +
> +	iio_device_unregister(indio_dev);
> +
> +	pm_runtime_dont_use_autosuspend(&client->dev);
> +	pm_runtime_disable(&client->dev);
As I see it we can maintain the ordering against probe (i.e.
remove is reverse of probe) by putting these two before the
iio_device_unregister.

The pm_runtime_set_active should also be before iio_device_register
thus allowing the rest of this to be a correct reversing of steps
as well.

> +	pm_runtime_set_suspended(&client->dev);
> +	pm_runtime_put_noidle(&client->dev);

This last call is an oddity and basically just marks that we are done
with all runtime_pm calls and makes the reference counter got to 0
if we are currently enabled?.  From a quick look it isn't unwinding any
of the steps visible in probe.

Hmm. A quick look at other drivers suggests to me that this is needed
to drop the use count if the buffer happens to be enabled.
No interestingly you don't have the preenable / postdisable logic
that would actually keep the power up if the buffer is enabled...


> +
> +	return vcnl4035_set_als_power_state(iio_priv(indio_dev),
> +					VCNL4035_MODE_ALS_DISABLE);
> +}
> +
> +#ifdef CONFIG_PM
> +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;
> +}
> +#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 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,
> +};
> +
> +module_i2c_driver(vcnl4035_driver);
> +
> +MODULE_AUTHOR("Parthiban Nallathambi <pn@xxxxxxx>");
> +MODULE_DESCRIPTION("VCNL4035 Ambient Light Sensor driver");
> +MODULE_LICENSE("GPL v2");