Date:   Mon, 11 Feb 2019 15:58:27 +0100 (CET)
From:   Peter Meerwald-Stadler <pmeerw@...erw.net>
To:     Robert Eshleman <bobbyeshleman@...il.com>
cc:     Jonathan Cameron <jic23@...nel.org>,
        Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org
Subject: Re: [PATCH 1/3] iio: light: Add driver for ap3216c

On Sun, 10 Feb 2019, Robert Eshleman wrote:

> This patch adds support for the ap3216c ambient light and proximity
> sensor.

comments below
 
> Supported features include:
> 
> * Illuminance (lux)
> * Proximity (raw)
> * IR (raw)
> * Rising/falling threshold events for illuminance and proximity
> * Calibration scale for illuminance
> * Calibration bias for proximity
> 
> Signed-off-by: Robert Eshleman <bobbyeshleman@...il.com>
> ---
>  drivers/iio/light/Kconfig   |  11 +
>  drivers/iio/light/Makefile  |   1 +
>  drivers/iio/light/ap3216c.c | 793 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 805 insertions(+)
>  create mode 100644 drivers/iio/light/ap3216c.c
> 
> diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
> index 36f458433480..74688d19beb1 100644
> --- a/drivers/iio/light/Kconfig
> +++ b/drivers/iio/light/Kconfig
> @@ -41,6 +41,17 @@ config AL3320A
>  	 To compile this driver as a module, choose M here: the
>  	 module will be called al3320a.
>  
> +config AP3216C
> +	tristate "AP3216C Ambient Light and Proximity sensor"
> +	select REGMAP_I2C
> +	depends on I2C
> +	help
> +	  Say Y here to build a driver for the AP3216C Ambient Light and
> +	  Proximity sensor.
> +
> +	  To compile this driver as a module, choose M here: the
> +	  module will be called ap3216c.
> +
>  config APDS9300
>  	tristate "APDS9300 ambient light sensor"
>  	depends on I2C
> diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
> index 286bf3975372..7d2f8fa0f30d 100644
> --- a/drivers/iio/light/Makefile
> +++ b/drivers/iio/light/Makefile
> @@ -7,6 +7,7 @@
>  obj-$(CONFIG_ACPI_ALS)		+= acpi-als.o
>  obj-$(CONFIG_ADJD_S311)		+= adjd_s311.o
>  obj-$(CONFIG_AL3320A)		+= al3320a.o
> +obj-$(CONFIG_AP3216C)		+= ap3216c.o
>  obj-$(CONFIG_APDS9300)		+= apds9300.o
>  obj-$(CONFIG_APDS9960)		+= apds9960.o
>  obj-$(CONFIG_BH1750)		+= bh1750.o
> diff --git a/drivers/iio/light/ap3216c.c b/drivers/iio/light/ap3216c.c
> new file mode 100644
> index 000000000000..12802b45c01c
> --- /dev/null
> +++ b/drivers/iio/light/ap3216c.c
> @@ -0,0 +1,793 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * AP3216C Ambient Light and Infrared Proximity Sensor
> + *
> + * Copyright (c) 2019, Robert Eshleman.
> + *
> + * Datasheet: https://pdf-datasheet-datasheet.netdna-ssl.com/pdf-down/A/P/3/AP3216C-LITE-ON.pdf
> + *
> + * 7-bit I2C slave address 0x1E
> + */
> +
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/i2c.h>
> +#include <linux/interrupt.h>
> +#include <linux/bits.h>
> +#include <linux/regmap.h>
> +#include <linux/iio/iio.h>
> +#include <linux/iio/sysfs.h>
> +#include <linux/iio/events.h>
> +
> +#define AP3216C_DRV_NAME "ap3216c"
> +
> +/* register addresses */
> +#define AP3216C_SYS 0x0
> +#define AP3216C_INT_STATUS 0x01
> +#define AP3216C_INT_CLR 0x02
> +#define AP3216C_IR_DATA_LO 0x0A
> +#define AP3216C_IR_DATA_HI 0x0B
> +#define AP3216C_ALS_DATA_LO 0x0C
> +#define AP3216C_ALS_DATA_HI 0x0D
> +#define AP3216C_PS_DATA_LO 0x0E
> +#define AP3216C_PS_DATA_HI 0x0F
> +#define AP3216C_ALS_CFG 0x10
> +#define AP3216C_ALS_CALIB 0x19
> +#define AP3216C_ALS_LO_THR_LO 0x1A
> +#define AP3216C_ALS_LO_THR_HI 0x1B
> +#define AP3216C_ALS_HI_THR_LO 0x1C
> +#define AP3216C_ALS_HI_THR_HI 0x1D
> +#define AP3216C_PS_CFG 0x20
> +#define AP3216C_PS_CALIB_LO 0x28
> +#define AP3216C_PS_CALIB_HI 0x29
> +#define AP3216C_PS_LO_THR_LO 0x2A
> +#define AP3216C_PS_LO_THR_HI 0x2B
> +#define AP3216C_PS_HI_THR_LO 0x2C
> +#define AP3216C_PS_HI_THR_HI 0x2D
> +
> +/* SYS_MODE mask and config value */
> +#define AP3216C_SYS_MODE_ALS_PS GENMASK(1, 0)
> +#define AP3216C_SYS_MODE_ALS_ONLY 0x01
> +
> +/* INT_STATUS masks and config value */
> +#define AP3216C_INT_STATUS_ALS_MASK 1
> +#define AP3216C_INT_STATUS_PS_MASK (1 << 1)

use BIT()?

> +#define AP3216C_INT_STATUS_CLR GENMASK(1, 0)
> +#define AP3216C_INT_CLR_MANUAL 1
> +
> +/* IR_DATA mask/shift */
> +#define AP3216C_IR_DATA_LO_MASK GENMASK(1, 0)
> +#define AP3216C_IR_DATA_HI_SHIFT 2
> +
> +/* ALS_DATA shift and fractional helper */
> +#define AP3216C_ALS_DATA_HI_SHIFT 8
> +#define AP3216C_ALS_DATA_DENOM 100000
> +
> +/* ALS_CALIB masks/shifts */
> +#define AP3216C_ALS_CALIB_INT_MASK GENMASK(7, 6)
> +#define AP3216C_ALS_CALIB_INT_SHIFT 6
> +#define AP3216C_ALS_CALIB_DEC_MASK GENMASK(5, 0)
> +
> +/* PS_DATA shifts/masks/bits */
> +#define AP3216C_PS_DATA_LO_MASK GENMASK(3, 0)
> +#define AP3216C_PS_DATA_LO_IR_OF BIT(6)
> +#define AP3216C_PS_DATA_HI_MASK GENMASK(5, 0)
> +#define AP3216C_PS_DATA_HI_SHIFT 4
> +#define AP3216C_PS_DATA_HI_IR_OF BIT(6)
> +
> +/* ALS_CFG masks */
> +#define AP3216C_ALS_CFG_GAIN_MASK GENMASK(5, 4)
> +
> +/* ALS_CALIB shifts */
> +#define AP3216C_ALS_CALIB_INT_SHIFT 6
> +
> +/* ALS_HI_THR masks and shifts */
> +#define AP3216C_ALS_HI_THR_LO_MASK GENMASK(7, 0)
> +#define AP3216C_ALS_HI_THR_HI_SHIFT 8
> +#define AP3216C_ALS_HI_THR_HI_MASK GENMASK(7, 4)
> +#define AP3216C_ALS_HI_THR_HI_SHIFT 8
> +
> +/* ALS_LO_THR masks and shifts */
> +#define AP3216C_ALS_LO_THR_LO_MASK GENMASK(3, 0)
> +#define AP3216C_ALS_LO_THR_HI_MASK GENMASK(7, 4)
> +#define AP3216C_ALS_LO_THR_HI_SHIFT 8
> +
> +/* PS_CFG reg mask/shift/bit values */
> +#define AP3216C_PS_CFG_GAIN_MASK GENMASK(3, 2)
> +#define AP3216C_PS_CFG_GAIN_SHIFT 2
> +#define AP3216C_PS_CFG_GAIN(val) \
> +	(1 << ((val & AP3216C_PS_CFG_GAIN_MASK) >> AP3216C_PS_CFG_GAIN_SHIFT))
> +
> +/* PS_LO and PS_HI shift/mask and multiplier values */
> +#define AP3216C_PS_LO_THR_HI_MULT 4
> +#define AP3216C_PS_HI_THR_HI_SHIFT 2
> +#define AP3216C_PS_HI_THR_HI_MULT 4
> +
> +/* PS_THR_LO and PS_THR_HI masks */
> +#define AP3216C_PS_THR_LO_MASK GENMASK(1, 0)
> +#define AP3216C_PS_THR_HI_MASK GENMASK(10, 2)
> +
> +/* PS_CALIB_HI and PS_CALIB_LO shift/mask/bit values */
> +#define AP3216C_PS_CALIB_HI_SHIFT 1
> +#define AP3216C_PS_CALIB_HI_MASK GENMASK(8, 1)
> +#define AP3216C_PS_CALIB_LO_MASK BIT(0)
> +
> +/* ALS fractional helper values */
> +#define AP3216C_ALS_INTEG_MULT 10000
> +#define AP3216C_ALS_FRACT_DIV 100
> +
> +/* ALS_CALIB min/max values (0.0 <= ALS_CALIB <= 3.984375) */
> +#define AP3216C_ALS_CALIB_INT_MIN 0
> +#define AP3216C_ALS_CALIB_DEC_MIN 0
> +#define AP3216C_ALS_CALIB_INT_MAX 3
> +#define AP3216C_ALS_CALIB_DEC_MAX 984375
> +
> +/* ALS_CALIB conversion denominator */
> +#define AP3216C_ALS_CALIB_DENOM 64
> +
> +#define AP3216C_IIO_MULT 1000000
> +
> +static u16 ap3216c_gain_array[] = {

const

> +	3500,  /* 0.3500 lux resolution */
> +	 788,  /* 0.0788 lux resolution */
> +	 197,  /* 0.0197 lux resolution */
> +	  49,  /* 0.0049 lux resolution */
> +};
> +
> +struct ap3216c_data {
> +	struct regmap *regmap;
> +	struct i2c_client *client;
> +	bool als_thresh_en;
> +	bool prox_thresh_en;
> +};
> +
> +static const struct iio_event_spec ap3216c_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_shared_by_type = BIT(IIO_EV_INFO_ENABLE),
> +	},
> +};
> +
> +static const struct iio_chan_spec ap3216c_channels[] = {
> +	{
> +		.type = IIO_LIGHT,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
> +				      BIT(IIO_CHAN_INFO_CALIBSCALE),

should probably be INFO_SCALE, as is used to select sensitivity and is not 
meant to calibrate the chip

> +		.event_spec = ap3216c_event_spec,
> +		.num_event_specs = ARRAY_SIZE(ap3216c_event_spec),
> +	},
> +	{
> +		.type = IIO_PROXIMITY,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
> +				      BIT(IIO_CHAN_INFO_CALIBBIAS),

should probably be INFO_SCALE

> +		.event_spec = ap3216c_event_spec,
> +		.num_event_specs = ARRAY_SIZE(ap3216c_event_spec),
> +	},
> +	{
> +		.type = IIO_LIGHT,
> +		.modified = 1,
> +		.channel2 = IIO_MOD_LIGHT_IR,
> +		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
> +	}
> +};
> +
> +static int ap3216c_write_event_value(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 ap3216c_data *data = iio_priv(indio_dev);
> +	int cfg, gain;
> +	int integral, fractional;
> +	int lo, hi;
> +	u16 thr;
> +	int ret;
> +
> +	switch (chan->type) {
> +	case IIO_LIGHT:
> +		ret = regmap_read(data->regmap, AP3216C_ALS_CFG, &cfg);
> +		if (ret < 0)
> +			return ret;
> +
> +		gain = ap3216c_gain_array[cfg & AP3216C_ALS_CFG_GAIN_MASK];
> +		integral = val * AP3216C_ALS_INTEG_MULT / gain;
> +		fractional = val2 / AP3216C_ALS_FRACT_DIV / gain;
> +
> +		thr = integral + fractional;
> +
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:

mutex around the two writes to have atomic update of regs?

> +			ret = regmap_write(data->regmap, AP3216C_ALS_HI_THR_LO,
> +					   thr & AP3216C_ALS_HI_THR_LO_MASK);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_write(data->regmap,
> +					   AP3216C_ALS_HI_THR_HI,
> +					   (thr & AP3216C_ALS_HI_THR_HI_MASK) >>
> +					   AP3216C_ALS_HI_THR_HI_SHIFT);
> +			if (ret < 0)
> +				return ret;
> +
> +			return ret;
> +
> +		case IIO_EV_DIR_FALLING:
> +			ret = regmap_write(data->regmap,
> +					   AP3216C_ALS_LO_THR_LO,
> +					   thr & AP3216C_ALS_LO_THR_LO_MASK);
> +
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_write(data->regmap,
> +					   AP3216C_ALS_LO_THR_HI,
> +					   (thr & AP3216C_ALS_LO_THR_HI_MASK) >>
> +					   AP3216C_ALS_LO_THR_HI_SHIFT);
> +			if (ret < 0)
> +				return ret;
> +
> +			return ret;
> +
> +		default:
> +			return -EINVAL;
> +		}
> +		return -EINVAL;
> +
> +	case IIO_PROXIMITY:
> +		lo = val & AP3216C_PS_THR_LO_MASK;
> +		hi = (val & AP3216C_PS_THR_HI_MASK) >>
> +			AP3216C_PS_HI_THR_HI_SHIFT;
> +
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			ret = regmap_write(data->regmap,
> +					   AP3216C_PS_HI_THR_LO, lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			return regmap_write(data->regmap,
> +					    AP3216C_PS_HI_THR_HI, hi);
> +
> +		case IIO_EV_DIR_FALLING:
> +			ret = regmap_write(data->regmap,
> +					   AP3216C_PS_LO_THR_LO, lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			return regmap_write(data->regmap,
> +					    AP3216C_PS_LO_THR_HI, hi);
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	default:
> +		return -EINVAL;
> +	}
> +	return -EINVAL;

should not be needed

> +}
> +
> +static int ap3216c_read_event_value(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 ap3216c_data *data = iio_priv(indio_dev);
> +	unsigned int lo, hi;
> +	int ret;
> +
> +	switch (chan->type) {
> +	case IIO_LIGHT:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_HI_THR_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_HI_THR_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +			*val = (hi << AP3216C_ALS_HI_THR_HI_SHIFT) | lo;
> +			return IIO_VAL_INT;
> +
> +		case IIO_EV_DIR_FALLING:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_LO_THR_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_LO_THR_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +			*val = (hi << AP3216C_ALS_LO_THR_HI_SHIFT) | lo;
> +			return IIO_VAL_INT;
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	case IIO_PROXIMITY:
> +		switch (dir) {
> +		case IIO_EV_DIR_RISING:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_HI_THR_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_HI_THR_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +			*val = (hi * AP3216C_PS_HI_THR_HI_MULT) +
> +				(lo & AP3216C_PS_THR_LO_MASK);
> +
> +			return IIO_VAL_INT;
> +
> +		case IIO_EV_DIR_FALLING:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_LO_THR_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_LO_THR_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +			*val = (hi * AP3216C_PS_LO_THR_HI_MULT) +
> +				(lo & AP3216C_PS_THR_LO_MASK);
> +
> +			return IIO_VAL_INT;
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return -EINVAL;

should not be needed; compilers are smart enough to see that this is 
unreachable (here and elsewhere)

> +}
> +
> +static int ap3216c_read_event_config(struct iio_dev *indio_dev,
> +				    const struct iio_chan_spec *chan,
> +				    enum iio_event_type type,
> +				    enum iio_event_direction dir)
> +{
> +	struct ap3216c_data *data = iio_priv(indio_dev);
> +
> +	switch (chan->type) {
> +	case IIO_LIGHT:
> +		return data->als_thresh_en;
> +
> +	case IIO_PROXIMITY:
> +		return data->prox_thresh_en;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static int ap3216c_write_event_config(struct iio_dev *indio_dev,
> +				     const struct iio_chan_spec *chan,
> +				     enum iio_event_type type,
> +				     enum iio_event_direction dir, int state)
> +{
> +	struct ap3216c_data *data = iio_priv(indio_dev);
> +
> +	switch (chan->type) {
> +	case IIO_LIGHT:
> +		data->als_thresh_en = state;
> +		return 0;
> +
> +	case IIO_PROXIMITY:
> +		data->prox_thresh_en = state;
> +		return 0;
> +
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return -EINVAL;
> +}
> +
> +static const struct regmap_config ap3216c_regmap_config = {
> +	.reg_bits = 8,
> +	.val_bits = 8,
> +	.max_register = AP3216C_PS_HI_THR_HI,
> +};
> +
> +/**
> + * Returns integral part of decimal between 0.0 and 3.984275
> + */
> +static int ap3216c_als_calibscale_int(int val)
> +{
> +	if (val > AP3216C_ALS_CALIB_INT_MAX)
> +		return AP3216C_ALS_CALIB_INT_MAX;
> +
> +	if (val <= AP3216C_ALS_CALIB_INT_MIN)
> +		return AP3216C_ALS_CALIB_INT_MIN;
> +
> +	return val;
> +}
> +
> +/**
> + * Returns decimal part of decimal number between 0.0 and 3.984275
> + */
> +static int ap3216c_als_calibscale_dec(int val, int val2)
> +{
> +	/* Return max decimal if number exceeds calibscale max */
> +	if (val > AP3216C_ALS_CALIB_INT_MAX ||
> +	    (val == AP3216C_ALS_CALIB_INT_MAX &&
> +	     val2 > AP3216C_ALS_CALIB_DEC_MAX))
> +		return AP3216C_ALS_CALIB_DEC_MAX;
> +
> +	/* Floor the decimal if integral below minimum */
> +	if (val <= AP3216C_ALS_CALIB_INT_MIN)
> +		return AP3216C_ALS_CALIB_DEC_MIN;
> +
> +	/* Floor the decimal if decimal below minimum */
> +	if (val2 < AP3216C_ALS_CALIB_DEC_MIN)
> +		return AP3216C_ALS_CALIB_DEC_MIN;
> +
> +	/* Return max decimal if decimal above maximum */
> +	if (val2 > AP3216C_ALS_CALIB_DEC_MAX)
> +		return AP3216C_ALS_CALIB_DEC_MAX;
> +
> +	return val2;
> +}
> +
> +static int ap3216c_write_raw(struct iio_dev *indio_dev,
> +			     struct iio_chan_spec const *chan,
> +			     int val, int val2, long mask)
> +{
> +	struct ap3216c_data *data = iio_priv(indio_dev);
> +	int integral, decimal;
> +	int tmp;
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_CALIBSCALE:
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			integral = ap3216c_als_calibscale_int(val);
> +			decimal = ap3216c_als_calibscale_dec(val, val2);
> +
> +			tmp = integral << AP3216C_ALS_CALIB_INT_SHIFT;
> +
> +			/*
> +			 * Reverse scaling by multiplying by the scaling
> +			 * denominator and dividing by IIO multiplier.
> +			 */
> +			tmp |= (decimal * AP3216C_ALS_CALIB_DENOM) /
> +				AP3216C_IIO_MULT;
> +
> +			return regmap_write(data->regmap,
> +					    AP3216C_ALS_CALIB, tmp);
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	case IIO_CHAN_INFO_CALIBBIAS:
> +		switch (chan->type) {
> +		case IIO_PROXIMITY:
> +			ret = regmap_write(data->regmap, AP3216C_PS_CALIB_LO,
> +					   val & AP3216C_PS_CALIB_LO_MASK);
> +			if (ret < 0)
> +				return ret;
> +
> +			tmp = (val & AP3216C_PS_CALIB_HI_MASK) >>
> +				AP3216C_PS_CALIB_HI_SHIFT;
> +
> +			return regmap_write(data->regmap,
> +					    AP3216C_PS_CALIB_HI, tmp);
> +
> +		default:
> +			return -EINVAL;
> +		}
> +	default:
> +		return -EINVAL;
> +	}
> +	return -EINVAL;
> +}
> +
> +static int ap3216c_read_raw(struct iio_dev *indio_dev,
> +				struct iio_chan_spec const *chan,
> +				int *val, int *val2, long mask)
> +{
> +	struct ap3216c_data *data = iio_priv(indio_dev);
> +	int lo, hi;
> +	int cfg, tmp;
> +	int ret;
> +
> +	switch (mask) {
> +	case IIO_CHAN_INFO_CALIBSCALE:
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_CALIB, &tmp);
> +			if (ret < 0)
> +				return ret;
> +
> +			/* Scale is multiplied by 1/64 */
> +			*val = tmp;
> +			*val2 = AP3216C_ALS_CALIB_DENOM;
> +			return IIO_VAL_FRACTIONAL;
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	case IIO_CHAN_INFO_CALIBBIAS:
> +		switch (chan->type) {
> +		case IIO_PROXIMITY:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_CALIB_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_CALIB_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +
> +			*val = lo | (hi << AP3216C_PS_CALIB_HI_SHIFT);
> +			return IIO_VAL_INT;
> +
> +		default:
> +			return -EINVAL;
> +		}
> +
> +	case IIO_CHAN_INFO_PROCESSED:
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_DATA_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_DATA_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_ALS_CFG, &cfg);
> +			if (ret < 0)
> +				return ret;
> +
> +			tmp = (hi << AP3216C_ALS_DATA_HI_SHIFT) | lo;
> +			tmp *= ap3216c_gain_array[cfg & AP3216C_ALS_CFG_GAIN_MASK];
> +
> +			*val = tmp;
> +			*val2 = AP3216C_ALS_DATA_DENOM;
> +
> +			return IIO_VAL_FRACTIONAL;
> +		default:
> +			return -EINVAL;
> +		}
> +	case IIO_CHAN_INFO_RAW:
> +		switch (chan->type) {
> +		case IIO_LIGHT:
> +			if (chan->channel2 != IIO_MOD_LIGHT_IR)
> +				return -EINVAL;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_IR_DATA_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_IR_DATA_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +			tmp = lo & AP3216C_IR_DATA_LO_MASK;
> +			tmp |= hi << AP3216C_IR_DATA_HI_SHIFT;
> +			*val = tmp;
> +
> +			return IIO_VAL_INT;
> +
> +		case IIO_PROXIMITY:
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_DATA_LO, &lo);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_DATA_HI, &hi);
> +			if (ret < 0)
> +				return ret;
> +
> +			ret = regmap_read(data->regmap,
> +					  AP3216C_PS_CFG, &cfg);
> +			if (ret < 0)
> +				return ret;
> +
> +			tmp = lo & AP3216C_PS_DATA_LO_MASK;
> +			tmp |= (hi & AP3216C_PS_DATA_HI_MASK) <<
> +				AP3216C_PS_DATA_HI_SHIFT;
> +			*val = tmp * AP3216C_PS_CFG_GAIN(cfg);
> +
> +			return IIO_VAL_INT;
> +		default:
> +			return -EINVAL;
> +		}
> +	default:
> +		return -EINVAL;
> +	}
> +	return -EINVAL;
> +}
> +
> +static const struct iio_info ap3216c_info = {
> +	.read_raw = ap3216c_read_raw,
> +	.write_raw = ap3216c_write_raw,
> +	.read_event_value = ap3216c_read_event_value,
> +	.write_event_value = ap3216c_write_event_value,
> +	.read_event_config = ap3216c_read_event_config,
> +	.write_event_config = ap3216c_write_event_config,
> +};
> +
> +static int ap3216c_clear_int(struct ap3216c_data *data)

function needed?

> +{
> +	return regmap_write(data->regmap,
> +			    AP3216C_INT_STATUS, AP3216C_INT_STATUS_CLR);
> +}
> +
> +static irqreturn_t ap3216c_event_handler(int irq, void *p)
> +{
> +	struct iio_dev *indio_dev = p;
> +	struct ap3216c_data *data = iio_priv(indio_dev);
> +	int status;
> +	s64 timestamp;
> +	int ret;
> +
> +	ret = regmap_read(data->regmap, AP3216C_INT_STATUS, &status);
> +	if (ret) {
> +		/*
> +		 * Without being able to guarantee the interrupt came from
> +		 * this device, we must return IRQ_HANDLED instead of
> +		 * IRQ_NONE.
> +		 */
> +		dev_err(&data->client->dev, "error reading IRQ status\n");
> +		return IRQ_HANDLED;
> +	}
> +
> +	/* The IRQ was not from this device */
> +	if (!status)
> +		return IRQ_NONE;
> +
> +	timestamp = iio_get_time_ns(indio_dev);
> +	if ((status & AP3216C_INT_STATUS_PS_MASK) && data->prox_thresh_en)
> +		iio_push_event(indio_dev,
> +			       IIO_UNMOD_EVENT_CODE(IIO_PROXIMITY, 0,
> +						    IIO_EV_TYPE_THRESH,
> +						    IIO_EV_DIR_EITHER),
> +			       timestamp);
> +
> +	if ((status & AP3216C_INT_STATUS_ALS_MASK) && data->als_thresh_en)
> +		iio_push_event(indio_dev,
> +			       IIO_UNMOD_EVENT_CODE(IIO_LIGHT, 0,
> +						    IIO_EV_TYPE_THRESH,
> +						    IIO_EV_DIR_EITHER),
> +			       timestamp);
> +
> +	ret = ap3216c_clear_int(data);
> +	if (ret < 0)
> +		dev_err(&data->client->dev, "error clearing IRQ\n");
> +
> +	return IRQ_HANDLED;
> +}
> +
> +static int ap3216c_probe(struct i2c_client *client,
> +			  const struct i2c_device_id *id)
> +{
> +	struct ap3216c_data *data;
> +	struct iio_dev *indio_dev;
> +	int ret;
> +
> +	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
> +	if (!indio_dev)
> +		return -ENOMEM;
> +
> +	data = iio_priv(indio_dev);
> +	data->client = client;
> +	indio_dev->dev.parent = &client->dev;
> +	indio_dev->info = &ap3216c_info;
> +	indio_dev->name = AP3216C_DRV_NAME;
> +	indio_dev->channels = ap3216c_channels;
> +	indio_dev->num_channels = ARRAY_SIZE(ap3216c_channels);
> +
> +	data->regmap = devm_regmap_init_i2c(client, &ap3216c_regmap_config);
> +	if (IS_ERR(data->regmap)) {
> +		dev_err(&client->dev, "Failed to allocate register map\n");
> +		return PTR_ERR(data->regmap);
> +	}
> +
> +	/* Default to thresh events disabled */
> +	data->als_thresh_en = false;
> +	data->prox_thresh_en = false;
> +
> +	/*
> +	 * Require that that the interrupt is cleared only when the INT

that that

> +	 * register is written to, instead of when data is read.  This
> +	 * prevents the interrupt from falsely reporting IRQ_NONE.
> +	 */
> +	ret = regmap_write(data->regmap,
> +			   AP3216C_INT_CLR, AP3216C_INT_CLR_MANUAL);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Before setting up IRQ, clear any stale interrupt */
> +	ret = ap3216c_clear_int(data);
> +	if (ret < 0)
> +		return ret;
> +
> +	if (client->irq) {
> +		ret = devm_request_threaded_irq(&client->dev, client->irq,
> +						NULL, ap3216c_event_handler,
> +						IRQF_TRIGGER_FALLING |
> +						IRQF_SHARED | IRQF_ONESHOT,
> +						client->name, indio_dev);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	/* Enable ALS and PS+IR */
> +	ret = regmap_write(data->regmap, AP3216C_SYS, AP3216C_SYS_MODE_ALS_PS);
> +	if (ret < 0)
> +		return ret;
> +
> +	return devm_iio_device_register(&client->dev, indio_dev);
> +}
> +
> +static const struct of_device_id ap3216c_of_match[] = {
> +	{ .compatible = "liteon,ap3216c", },
> +	{ },
> +};
> +MODULE_DEVICE_TABLE(of, ap3216c_of_match);
> +
> +static const struct i2c_device_id ap3216c_id[] = {
> +	{"ap3216c", 0},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, ap3216c_id);
> +
> +static struct i2c_driver ap3216c_driver = {
> +	.driver = {
> +		.name	= AP3216C_DRV_NAME,
> +	},
> +	.probe		= ap3216c_probe,
> +	.id_table	= ap3216c_id,
> +};
> +module_i2c_driver(ap3216c_driver);
> +
> +MODULE_AUTHOR("Robert Eshleman <bobbyeshleman@...il.com>");
> +MODULE_DESCRIPTION("APC3216C Ambient Light and Proximity Sensor");
> +MODULE_LICENSE("GPL v2");
> 

-- 

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

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