Message-ID: <20191110104153.783e8ee2@archlinux>
Date:   Sun, 10 Nov 2019 10:41:53 +0000
From:   Jonathan Cameron <jic23@...nel.org>
To:     Rishi Gupta <gupt21@...il.com>
Cc:     knaack.h@....de, lars@...afoo.de, pmeerw@...erw.net,
        gregkh@...uxfoundation.org, tglx@...utronix.de,
        allison@...utok.net, alexios.zavras@...el.com, angus@...ea.ca,
        linux-iio@...r.kernel.org, linux-kernel@...r.kernel.org,
        robh+dt@...nel.org, mark.rutland@....com,
        devicetree@...r.kernel.org
Subject: Re: [PATCH v6 1/3] iio: light: add driver for veml6030 ambient
 light sensor

On Mon,  4 Nov 2019 21:08:24 +0530
Rishi Gupta <gupt21@...il.com> 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 <gupt21@...il.com>
One minor thing inline. I'll fix it up whilst applying but please
take a quick look at the result and check I haven't messed it up!

Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan


> ---
> Changes in v6:
> * Move devm_add_action_or_reset() after veml6030_hw_init()
> * Reading/Writing/Show for period now takes values in seconds
> 
> Changes in v5:
> * Removed setting val2 when returning IIO_VAL_INT
> * Removed redundant return from veml6030_read_raw()
> * Set 4000 as min time in usleep_range(4000, 4002)
> * Removed PSM support completely
> 
> 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 | 911 +++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 923 insertions(+)
>  create mode 100644 drivers/iio/light/veml6030.c
> 
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 4a1a883..f9d27ef 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -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
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index 00d1f9b..5e0c40b 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -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
> diff --git a/drivers/iio/light/veml6030.c b/drivers/iio/light/veml6030.c
> new file mode 100644
> index 0000000..a38b110
> --- /dev/null
> +++ b/drivers/iio/light/veml6030.c
> @@ -0,0 +1,911 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * VEML6030 Ambient Light Sensor
> + *
> + * Copyright (c) 2019, Rishi Gupta <gupt21@...il.com>
> + *
> + * 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");
> +
> +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,
> +	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 the interrupt.
> + */
> +static const char * const period_values[] = {
> +		"0.1 0.2 0.4 0.8",
> +		"0.2 0.4 0.8 1.6",
> +		"0.4 0.8 1.6 3.2",
> +		"0.8 1.6 3.2 6.4",
> +		"0.05 0.1 0.2 0.4",
> +		"0.025 0.050 0.1 0.2"
> +};
> +
> +/*
> + * Return list of valid period values in seconds corresponding to
> + * the currently active integration time.
> + */
> +static ssize_t in_illuminance_period_available_show(struct device *dev,
> +				struct device_attribute *attr, char *buf)
> +{
> +	int ret, reg, x;
> +	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> +	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;
> +	}
> +
> +	ret = ((reg >> 6) & 0xF);
> +	switch (ret) {
> +	case 0:
> +	case 1:
> +	case 2:
> +	case 3:
> +		x = ret;
> +		break;
> +	case 8:
> +		x = 4;
> +		break;
> +	case 12:
> +		x = 5;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return snprintf(buf, PAGE_SIZE, "%s\n", period_values[x]);
> +}
> +
> +static IIO_DEVICE_ATTR_RO(in_illuminance_period_available, 0);
> +
> +static struct attribute *veml6030_event_attributes[] = {
> +	&iio_dev_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),

These last two should be one entry.   I'll fix that up but
please run a quick test in case I'm missing anything.

> +	},
> +};
> +
> +/* 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_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 read als conf 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;
> +}
> +
> +static int veml6030_read_persistence(struct iio_dev *indio_dev,
> +						int *val, int *val2)
> +{
> +	int ret, reg, period, x, y;
> +	struct veml6030_data *data = iio_priv(indio_dev);
> +
> +	ret = veml6030_get_intgrn_tm(indio_dev, &x, &y);
> +	if (ret < 0)
> +		return ret;
> +
> +	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);
> +	}
> +
> +	/* integration time multiplied by 1/2/4/8 */
> +	period = y * (1 << ((reg >> 4) & 0x03));
> +
> +	*val = period / 1000000;
> +	*val2 = period % 1000000;
> +
> +	return IIO_VAL_INT_PLUS_MICRO;
> +}
> +
> +static int veml6030_write_persistence(struct iio_dev *indio_dev,
> +						int val, int val2)
> +{
> +	int ret, period, x, y;
> +	struct veml6030_data *data = iio_priv(indio_dev);
> +
> +	ret = veml6030_get_intgrn_tm(indio_dev, &x, &y);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (!val) {
> +		period = val2 / y;
> +	} else {
> +		if ((val == 1) && (val2 == 600000))
> +			period = 1600000 / y;
> +		else if ((val == 3) && (val2 == 200000))
> +			period = 3200000 / y;
> +		else if ((val == 6) && (val2 == 400000))
> +			period = 6400000 / y;
> +		else
> +			period = -1;
> +	}
> +
> +	if (period <= 0 || period > 8 || hweight8(period) != 1)
> +		return -EINVAL;
> +
> +	ret = regmap_update_bits(data->regmap, VEML6030_REG_ALS_CONF,
> +				VEML6030_ALS_PERS, (ffs(period) - 1) << 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 read als conf 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;
> +	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;
> +}
> +
> +/*
> + * 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;
> +			return IIO_VAL_INT;
> +		case IIO_INTENSITY:
> +			ret = regmap_read(regmap, VEML6030_REG_WH_DATA, &reg);
> +			if (ret < 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;
> +			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)
> +{
> +	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;
> +	}
> +}
> +
> +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;
> +	}
> +
> +	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(4000, 4002);
> +
> +	/* 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;
> +	}
> +
> +	ret = veml6030_hw_init(indio_dev);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = devm_add_action_or_reset(&client->dev,
> +					veml6030_als_shut_down_action, data);
> +	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));

Hmm. For platform devices there was a recent move to get rid of the
conversion dance going on here (it's the same as dev_get_drvdata(dev))
but we seem to be sticking to this for for i2c devices.
 
> +	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 <gupt21@...il.com>");
> +MODULE_DESCRIPTION("VEML6030 Ambient Light Sensor");
> +MODULE_LICENSE("GPL v2");

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