drivers/iio/light/cm3232.c - kernel/quantenna - Git at Google

 /*
  * CM3232 Ambient Light Sensor
  *
  * Copyright (C) 2014-2015 Capella Microsystems Inc.
  * Author: Kevin Tsai <ktsai@capellamicro.com>
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2, as published
  * by the Free Software Foundation.
  *
  * IIO driver for CM3232 (7-bit I2C slave address 0x10).
  */

 #include <linux/i2c.h>
 #include <linux/module.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 #include <linux/init.h>

 /* Registers Address */
 #define CM3232_REG_ADDR_CMD		0x00
 #define CM3232_REG_ADDR_ALS		0x50
 #define CM3232_REG_ADDR_ID		0x53

 #define CM3232_CMD_ALS_DISABLE		BIT(0)

 #define CM3232_CMD_ALS_IT_SHIFT		2
 #define CM3232_CMD_ALS_IT_MASK		(BIT(2) | BIT(3) | BIT(4))
 #define CM3232_CMD_ALS_IT_DEFAULT	(0x01 << CM3232_CMD_ALS_IT_SHIFT)

 #define CM3232_CMD_ALS_RESET		BIT(6)

 #define CM3232_CMD_DEFAULT		CM3232_CMD_ALS_IT_DEFAULT

 #define CM3232_HW_ID			0x32
 #define CM3232_CALIBSCALE_DEFAULT	100000
 #define CM3232_CALIBSCALE_RESOLUTION	100000
 #define CM3232_MLUX_PER_LUX		1000

 #define CM3232_MLUX_PER_BIT_DEFAULT	64
 #define CM3232_MLUX_PER_BIT_BASE_IT	100000

 static const struct {
 	int val;
 	int val2;
 	u8 it;
 } cm3232_als_it_scales[] = {
 	{0, 100000, 0},	/* 0.100000 */
 	{0, 200000, 1},	/* 0.200000 */
 	{0, 400000, 2},	/* 0.400000 */
 	{0, 800000, 3},	/* 0.800000 */
 	{1, 600000, 4},	/* 1.600000 */
 	{3, 200000, 5},	/* 3.200000 */
 };

 struct cm3232_als_info {
 	u8 regs_cmd_default;
 	u8 hw_id;
 	int calibscale;
 	int mlux_per_bit;
 	int mlux_per_bit_base_it;
 };

 static struct cm3232_als_info cm3232_als_info_default = {
 	.regs_cmd_default = CM3232_CMD_DEFAULT,
 	.hw_id = CM3232_HW_ID,
 	.calibscale = CM3232_CALIBSCALE_DEFAULT,
 	.mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
 	.mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
 };

 struct cm3232_chip {
 	struct i2c_client *client;
 	struct cm3232_als_info *als_info;
 	u8 regs_cmd;
 	u16 regs_als;
 };

 /**
  * cm3232_reg_init() - Initialize CM3232
  * @chip:	pointer of struct cm3232_chip.
  *
  * Check and initialize CM3232 ambient light sensor.
  *
  * Return: 0 for success; otherwise for error code.
  */
 static int cm3232_reg_init(struct cm3232_chip *chip)
 {
 	struct i2c_client *client = chip->client;
 	s32 ret;

 	chip->als_info = &cm3232_als_info_default;

 	/* Identify device */
 	ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
 	if (ret < 0) {
 		dev_err(&chip->client->dev, "Error reading addr_id\n");
 		return ret;
 	}

 	if ((ret & 0xFF) != chip->als_info->hw_id)
 		return -ENODEV;

 	/* Disable and reset device */
 	chip->regs_cmd = CM3232_CMD_ALS_DISABLE | CM3232_CMD_ALS_RESET;
 	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 					chip->regs_cmd);
 	if (ret < 0) {
 		dev_err(&chip->client->dev, "Error writing reg_cmd\n");
 		return ret;
 	}

 	/* Register default value */
 	chip->regs_cmd = chip->als_info->regs_cmd_default;

 	/* Configure register */
 	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 					chip->regs_cmd);
 	if (ret < 0)
 		dev_err(&chip->client->dev, "Error writing reg_cmd\n");

 	return 0;
 }

 /**
  *  cm3232_read_als_it() - Get sensor integration time
  *  @chip:	pointer of struct cm3232_chip
  *  @val:	pointer of int to load the integration (sec).
  *  @val2:	pointer of int to load the integration time (microsecond).
  *
  *  Report the current integration time.
  *
  *  Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
  */
 static int cm3232_read_als_it(struct cm3232_chip *chip, int *val, int *val2)
 {
 	u16 als_it;
 	int i;

 	als_it = chip->regs_cmd;
 	als_it &= CM3232_CMD_ALS_IT_MASK;
 	als_it >>= CM3232_CMD_ALS_IT_SHIFT;
 	for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
 		if (als_it == cm3232_als_it_scales[i].it) {
 			*val = cm3232_als_it_scales[i].val;
 			*val2 = cm3232_als_it_scales[i].val2;
 			return IIO_VAL_INT_PLUS_MICRO;
 		}
 	}

 	return -EINVAL;
 }

 /**
  * cm3232_write_als_it() - Write sensor integration time
  * @chip:	pointer of struct cm3232_chip.
  * @val:	integration time in second.
  * @val2:	integration time in microsecond.
  *
  * Convert integration time to sensor value.
  *
  * Return: i2c_smbus_write_byte_data command return value.
  */
 static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)
 {
 	struct i2c_client *client = chip->client;
 	u16 als_it, cmd;
 	int i;
 	s32 ret;

 	for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
 		if (val == cm3232_als_it_scales[i].val &&
 			val2 == cm3232_als_it_scales[i].val2) {

 			als_it = cm3232_als_it_scales[i].it;
 			als_it <<= CM3232_CMD_ALS_IT_SHIFT;

 			cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;
 			cmd |= als_it;
 			ret = i2c_smbus_write_byte_data(client,
 							CM3232_REG_ADDR_CMD,
 							cmd);
 			if (ret < 0)
 				return ret;
 			chip->regs_cmd = cmd;
 			return 0;
 		}
 	}
 	return -EINVAL;
 }

 /**
  * cm3232_get_lux() - report current lux value
  * @chip:	pointer of struct cm3232_chip.
  *
  * Convert sensor data to lux.  It depends on integration
  * time and calibscale variable.
  *
  * Return: Zero or positive value is lux, otherwise error code.
  */
 static int cm3232_get_lux(struct cm3232_chip *chip)
 {
 	struct i2c_client *client = chip->client;
 	struct cm3232_als_info *als_info = chip->als_info;
 	int ret;
 	int val, val2;
 	int als_it;
 	u64 lux;

 	/* Calculate mlux per bit based on als_it */
 	ret = cm3232_read_als_it(chip, &val, &val2);
 	if (ret < 0)
 		return -EINVAL;
 	als_it = val * 1000000 + val2;
 	lux = (__force u64)als_info->mlux_per_bit;
 	lux *= als_info->mlux_per_bit_base_it;
 	lux = div_u64(lux, als_it);

 	ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);
 	if (ret < 0) {
 		dev_err(&client->dev, "Error reading reg_addr_als\n");
 		return ret;
 	}

 	chip->regs_als = (u16)ret;
 	lux *= chip->regs_als;
 	lux *= als_info->calibscale;
 	lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);
 	lux = div_u64(lux, CM3232_MLUX_PER_LUX);

 	if (lux > 0xFFFF)
 		lux = 0xFFFF;

 	return (int)lux;
 }

 static int cm3232_read_raw(struct iio_dev *indio_dev,
 			struct iio_chan_spec const *chan,
 			int *val, int *val2, long mask)
 {
 	struct cm3232_chip *chip = iio_priv(indio_dev);
 	struct cm3232_als_info *als_info = chip->als_info;
 	int ret;

 	switch (mask) {
 	case IIO_CHAN_INFO_PROCESSED:
 		ret = cm3232_get_lux(chip);
 		if (ret < 0)
 			return ret;
 		*val = ret;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_CALIBSCALE:
 		*val = als_info->calibscale;
 		return IIO_VAL_INT;
 	case IIO_CHAN_INFO_INT_TIME:
 		return cm3232_read_als_it(chip, val, val2);
 	}

 	return -EINVAL;
 }

 static int cm3232_write_raw(struct iio_dev *indio_dev,
 			struct iio_chan_spec const *chan,
 			int val, int val2, long mask)
 {
 	struct cm3232_chip *chip = iio_priv(indio_dev);
 	struct cm3232_als_info *als_info = chip->als_info;

 	switch (mask) {
 	case IIO_CHAN_INFO_CALIBSCALE:
 		als_info->calibscale = val;
 		return 0;
 	case IIO_CHAN_INFO_INT_TIME:
 		return cm3232_write_als_it(chip, val, val2);
 	}

 	return -EINVAL;
 }

 /**
  * cm3232_get_it_available() - Get available ALS IT value
  * @dev:	pointer of struct device.
  * @attr:	pointer of struct device_attribute.
  * @buf:	pointer of return string buffer.
  *
  * Display the available integration time in second.
  *
  * Return: string length.
  */
 static ssize_t cm3232_get_it_available(struct device *dev,
 			struct device_attribute *attr, char *buf)
 {
 	int i, len;

 	for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)
 		len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
 			cm3232_als_it_scales[i].val,
 			cm3232_als_it_scales[i].val2);
 	return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
 }

 static const struct iio_chan_spec cm3232_channels[] = {
 	{
 		.type = IIO_LIGHT,
 		.info_mask_separate =
 			BIT(IIO_CHAN_INFO_PROCESSED) |
 			BIT(IIO_CHAN_INFO_CALIBSCALE) |
 			BIT(IIO_CHAN_INFO_INT_TIME),
 	}
 };

 static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
 			S_IRUGO, cm3232_get_it_available, NULL, 0);

 static struct attribute *cm3232_attributes[] = {
 	&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
 	NULL,
 };

 static const struct attribute_group cm3232_attribute_group = {
 	.attrs = cm3232_attributes
 };

 static const struct iio_info cm3232_info = {
 	.driver_module		= THIS_MODULE,
 	.read_raw		= &cm3232_read_raw,
 	.write_raw		= &cm3232_write_raw,
 	.attrs			= &cm3232_attribute_group,
 };

 static int cm3232_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct cm3232_chip *chip;
 	struct iio_dev *indio_dev;
 	int ret;

 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
 	if (!indio_dev)
 		return -ENOMEM;

 	chip = iio_priv(indio_dev);
 	i2c_set_clientdata(client, indio_dev);
 	chip->client = client;

 	indio_dev->dev.parent = &client->dev;
 	indio_dev->channels = cm3232_channels;
 	indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);
 	indio_dev->info = &cm3232_info;
 	indio_dev->name = id->name;
 	indio_dev->modes = INDIO_DIRECT_MODE;

 	ret = cm3232_reg_init(chip);
 	if (ret) {
 		dev_err(&client->dev,
 			"%s: register init failed\n",
 			__func__);
 		return ret;
 	}

 	return iio_device_register(indio_dev);
 }

 static int cm3232_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);

 	i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 		CM3232_CMD_ALS_DISABLE);

 	iio_device_unregister(indio_dev);

 	return 0;
 }

 static const struct i2c_device_id cm3232_id[] = {
 	{"cm3232", 0},
 	{}
 };

 #ifdef CONFIG_PM_SLEEP
 static int cm3232_suspend(struct device *dev)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 	struct cm3232_chip *chip = iio_priv(indio_dev);
 	struct i2c_client *client = chip->client;
 	int ret;

 	chip->regs_cmd |= CM3232_CMD_ALS_DISABLE;
 	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 					chip->regs_cmd);

 	return ret;
 }

 static int cm3232_resume(struct device *dev)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
 	struct cm3232_chip *chip = iio_priv(indio_dev);
 	struct i2c_client *client = chip->client;
 	int ret;

 	chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;
 	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
 					chip->regs_cmd | CM3232_CMD_ALS_RESET);

 	return ret;
 }

 static const struct dev_pm_ops cm3232_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(cm3232_suspend, cm3232_resume)};
 #endif

 MODULE_DEVICE_TABLE(i2c, cm3232_id);

 static const struct of_device_id cm3232_of_match[] = {
 	{.compatible = "capella,cm3232"},
 	{}
 };
 MODULE_DEVICE_TABLE(of, cm3232_of_match);

 static struct i2c_driver cm3232_driver = {
 	.driver = {
 		.name	= "cm3232",
 		.of_match_table = of_match_ptr(cm3232_of_match),
 #ifdef CONFIG_PM_SLEEP
 		.pm	= &cm3232_pm_ops,
 #endif
 	},
 	.id_table	= cm3232_id,
 	.probe		= cm3232_probe,
 	.remove		= cm3232_remove,
 };

 module_i2c_driver(cm3232_driver);

 MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
 MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
 MODULE_LICENSE("GPL");
	/*
	* CM3232 Ambient Light Sensor
	*
	* Copyright (C) 2014-2015 Capella Microsystems Inc.
	* Author: Kevin Tsai <ktsai@capellamicro.com>
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2, as published
	* by the Free Software Foundation.
	*
	* IIO driver for CM3232 (7-bit I2C slave address 0x10).
	*/

	#include <linux/i2c.h>
	#include <linux/module.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/sysfs.h>
	#include <linux/init.h>

	/* Registers Address */
	#define CM3232_REG_ADDR_CMD 0x00
	#define CM3232_REG_ADDR_ALS 0x50
	#define CM3232_REG_ADDR_ID 0x53

	#define CM3232_CMD_ALS_DISABLE BIT(0)

	#define CM3232_CMD_ALS_IT_SHIFT 2
	#define CM3232_CMD_ALS_IT_MASK (BIT(2) \| BIT(3) \| BIT(4))
	#define CM3232_CMD_ALS_IT_DEFAULT (0x01 << CM3232_CMD_ALS_IT_SHIFT)

	#define CM3232_CMD_ALS_RESET BIT(6)

	#define CM3232_CMD_DEFAULT CM3232_CMD_ALS_IT_DEFAULT

	#define CM3232_HW_ID 0x32
	#define CM3232_CALIBSCALE_DEFAULT 100000
	#define CM3232_CALIBSCALE_RESOLUTION 100000
	#define CM3232_MLUX_PER_LUX 1000

	#define CM3232_MLUX_PER_BIT_DEFAULT 64
	#define CM3232_MLUX_PER_BIT_BASE_IT 100000

	static const struct {
	int val;
	int val2;
	u8 it;
	} cm3232_als_it_scales[] = {
	{0, 100000, 0}, /* 0.100000 */
	{0, 200000, 1}, /* 0.200000 */
	{0, 400000, 2}, /* 0.400000 */
	{0, 800000, 3}, /* 0.800000 */
	{1, 600000, 4}, /* 1.600000 */
	{3, 200000, 5}, /* 3.200000 */
	};

	struct cm3232_als_info {
	u8 regs_cmd_default;
	u8 hw_id;
	int calibscale;
	int mlux_per_bit;
	int mlux_per_bit_base_it;
	};

	static struct cm3232_als_info cm3232_als_info_default = {
	.regs_cmd_default = CM3232_CMD_DEFAULT,
	.hw_id = CM3232_HW_ID,
	.calibscale = CM3232_CALIBSCALE_DEFAULT,
	.mlux_per_bit = CM3232_MLUX_PER_BIT_DEFAULT,
	.mlux_per_bit_base_it = CM3232_MLUX_PER_BIT_BASE_IT,
	};

	struct cm3232_chip {
	struct i2c_client *client;
	struct cm3232_als_info *als_info;
	u8 regs_cmd;
	u16 regs_als;
	};

	/**
	* cm3232_reg_init() - Initialize CM3232
	* @chip: pointer of struct cm3232_chip.
	*
	* Check and initialize CM3232 ambient light sensor.
	*
	* Return: 0 for success; otherwise for error code.
	*/
	static int cm3232_reg_init(struct cm3232_chip *chip)
	{
	struct i2c_client *client = chip->client;
	s32 ret;

	chip->als_info = &cm3232_als_info_default;

	/* Identify device */
	ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ID);
	if (ret < 0) {
	dev_err(&chip->client->dev, "Error reading addr_id\n");
	return ret;
	}

	if ((ret & 0xFF) != chip->als_info->hw_id)
	return -ENODEV;

	/* Disable and reset device */
	chip->regs_cmd = CM3232_CMD_ALS_DISABLE \| CM3232_CMD_ALS_RESET;
	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
	chip->regs_cmd);
	if (ret < 0) {
	dev_err(&chip->client->dev, "Error writing reg_cmd\n");
	return ret;
	}

	/* Register default value */
	chip->regs_cmd = chip->als_info->regs_cmd_default;

	/* Configure register */
	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
	chip->regs_cmd);
	if (ret < 0)
	dev_err(&chip->client->dev, "Error writing reg_cmd\n");

	return 0;
	}

	/**
	* cm3232_read_als_it() - Get sensor integration time
	* @chip: pointer of struct cm3232_chip
	* @val: pointer of int to load the integration (sec).
	* @val2: pointer of int to load the integration time (microsecond).
	*
	* Report the current integration time.
	*
	* Return: IIO_VAL_INT_PLUS_MICRO for success, otherwise -EINVAL.
	*/
	static int cm3232_read_als_it(struct cm3232_chip chip, int val, int *val2)
	{
	u16 als_it;
	int i;

	als_it = chip->regs_cmd;
	als_it &= CM3232_CMD_ALS_IT_MASK;
	als_it >>= CM3232_CMD_ALS_IT_SHIFT;
	for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
	if (als_it == cm3232_als_it_scales[i].it) {
	*val = cm3232_als_it_scales[i].val;
	*val2 = cm3232_als_it_scales[i].val2;
	return IIO_VAL_INT_PLUS_MICRO;
	}
	}

	return -EINVAL;
	}

	/**
	* cm3232_write_als_it() - Write sensor integration time
	* @chip: pointer of struct cm3232_chip.
	* @val: integration time in second.
	* @val2: integration time in microsecond.
	*
	* Convert integration time to sensor value.
	*
	* Return: i2c_smbus_write_byte_data command return value.
	*/
	static int cm3232_write_als_it(struct cm3232_chip *chip, int val, int val2)
	{
	struct i2c_client *client = chip->client;
	u16 als_it, cmd;
	int i;
	s32 ret;

	for (i = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++) {
	if (val == cm3232_als_it_scales[i].val &&
	val2 == cm3232_als_it_scales[i].val2) {

	als_it = cm3232_als_it_scales[i].it;
	als_it <<= CM3232_CMD_ALS_IT_SHIFT;

	cmd = chip->regs_cmd & ~CM3232_CMD_ALS_IT_MASK;
	cmd \|= als_it;
	ret = i2c_smbus_write_byte_data(client,
	CM3232_REG_ADDR_CMD,
	cmd);
	if (ret < 0)
	return ret;
	chip->regs_cmd = cmd;
	return 0;
	}
	}
	return -EINVAL;
	}

	/**
	* cm3232_get_lux() - report current lux value
	* @chip: pointer of struct cm3232_chip.
	*
	* Convert sensor data to lux. It depends on integration
	* time and calibscale variable.
	*
	* Return: Zero or positive value is lux, otherwise error code.
	*/
	static int cm3232_get_lux(struct cm3232_chip *chip)
	{
	struct i2c_client *client = chip->client;
	struct cm3232_als_info *als_info = chip->als_info;
	int ret;
	int val, val2;
	int als_it;
	u64 lux;

	/* Calculate mlux per bit based on als_it */
	ret = cm3232_read_als_it(chip, &val, &val2);
	if (ret < 0)
	return -EINVAL;
	als_it = val * 1000000 + val2;
	lux = (__force u64)als_info->mlux_per_bit;
	lux *= als_info->mlux_per_bit_base_it;
	lux = div_u64(lux, als_it);

	ret = i2c_smbus_read_word_data(client, CM3232_REG_ADDR_ALS);
	if (ret < 0) {
	dev_err(&client->dev, "Error reading reg_addr_als\n");
	return ret;
	}

	chip->regs_als = (u16)ret;
	lux *= chip->regs_als;
	lux *= als_info->calibscale;
	lux = div_u64(lux, CM3232_CALIBSCALE_RESOLUTION);
	lux = div_u64(lux, CM3232_MLUX_PER_LUX);

	if (lux > 0xFFFF)
	lux = 0xFFFF;

	return (int)lux;
	}

	static int cm3232_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct cm3232_chip *chip = iio_priv(indio_dev);
	struct cm3232_als_info *als_info = chip->als_info;
	int ret;

	switch (mask) {
	case IIO_CHAN_INFO_PROCESSED:
	ret = cm3232_get_lux(chip);
	if (ret < 0)
	return ret;
	*val = ret;
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_CALIBSCALE:
	*val = als_info->calibscale;
	return IIO_VAL_INT;
	case IIO_CHAN_INFO_INT_TIME:
	return cm3232_read_als_it(chip, val, val2);
	}

	return -EINVAL;
	}

	static int cm3232_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct cm3232_chip *chip = iio_priv(indio_dev);
	struct cm3232_als_info *als_info = chip->als_info;

	switch (mask) {
	case IIO_CHAN_INFO_CALIBSCALE:
	als_info->calibscale = val;
	return 0;
	case IIO_CHAN_INFO_INT_TIME:
	return cm3232_write_als_it(chip, val, val2);
	}

	return -EINVAL;
	}

	/**
	* cm3232_get_it_available() - Get available ALS IT value
	* @dev: pointer of struct device.
	* @attr: pointer of struct device_attribute.
	* @buf: pointer of return string buffer.
	*
	* Display the available integration time in second.
	*
	* Return: string length.
	*/
	static ssize_t cm3232_get_it_available(struct device *dev,
	struct device_attribute attr, char buf)
	{
	int i, len;

	for (i = 0, len = 0; i < ARRAY_SIZE(cm3232_als_it_scales); i++)
	len += scnprintf(buf + len, PAGE_SIZE - len, "%u.%06u ",
	cm3232_als_it_scales[i].val,
	cm3232_als_it_scales[i].val2);
	return len + scnprintf(buf + len, PAGE_SIZE - len, "\n");
	}

	static const struct iio_chan_spec cm3232_channels[] = {
	{
	.type = IIO_LIGHT,
	.info_mask_separate =
	BIT(IIO_CHAN_INFO_PROCESSED) \|
	BIT(IIO_CHAN_INFO_CALIBSCALE) \|
	BIT(IIO_CHAN_INFO_INT_TIME),
	}
	};

	static IIO_DEVICE_ATTR(in_illuminance_integration_time_available,
	S_IRUGO, cm3232_get_it_available, NULL, 0);

	static struct attribute *cm3232_attributes[] = {
	&iio_dev_attr_in_illuminance_integration_time_available.dev_attr.attr,
	NULL,
	};

	static const struct attribute_group cm3232_attribute_group = {
	.attrs = cm3232_attributes
	};

	static const struct iio_info cm3232_info = {
	.driver_module = THIS_MODULE,
	.read_raw = &cm3232_read_raw,
	.write_raw = &cm3232_write_raw,
	.attrs = &cm3232_attribute_group,
	};

	static int cm3232_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct cm3232_chip *chip;
	struct iio_dev *indio_dev;
	int ret;

	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
	if (!indio_dev)
	return -ENOMEM;

	chip = iio_priv(indio_dev);
	i2c_set_clientdata(client, indio_dev);
	chip->client = client;

	indio_dev->dev.parent = &client->dev;
	indio_dev->channels = cm3232_channels;
	indio_dev->num_channels = ARRAY_SIZE(cm3232_channels);
	indio_dev->info = &cm3232_info;
	indio_dev->name = id->name;
	indio_dev->modes = INDIO_DIRECT_MODE;

	ret = cm3232_reg_init(chip);
	if (ret) {
	dev_err(&client->dev,
	"%s: register init failed\n",
	__func__);
	return ret;
	}

	return iio_device_register(indio_dev);
	}

	static int cm3232_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);

	i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
	CM3232_CMD_ALS_DISABLE);

	iio_device_unregister(indio_dev);

	return 0;
	}

	static const struct i2c_device_id cm3232_id[] = {
	{"cm3232", 0},
	{}
	};

	#ifdef CONFIG_PM_SLEEP
	static int cm3232_suspend(struct device *dev)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct cm3232_chip *chip = iio_priv(indio_dev);
	struct i2c_client *client = chip->client;
	int ret;

	chip->regs_cmd \|= CM3232_CMD_ALS_DISABLE;
	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
	chip->regs_cmd);

	return ret;
	}

	static int cm3232_resume(struct device *dev)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
	struct cm3232_chip *chip = iio_priv(indio_dev);
	struct i2c_client *client = chip->client;
	int ret;

	chip->regs_cmd &= ~CM3232_CMD_ALS_DISABLE;
	ret = i2c_smbus_write_byte_data(client, CM3232_REG_ADDR_CMD,
	chip->regs_cmd \| CM3232_CMD_ALS_RESET);

	return ret;
	}

	static const struct dev_pm_ops cm3232_pm_ops = {
	SET_SYSTEM_SLEEP_PM_OPS(cm3232_suspend, cm3232_resume)};
	#endif

	MODULE_DEVICE_TABLE(i2c, cm3232_id);

	static const struct of_device_id cm3232_of_match[] = {
	{.compatible = "capella,cm3232"},
	{}
	};
	MODULE_DEVICE_TABLE(of, cm3232_of_match);

	static struct i2c_driver cm3232_driver = {
	.driver = {
	.name = "cm3232",
	.of_match_table = of_match_ptr(cm3232_of_match),
	#ifdef CONFIG_PM_SLEEP
	.pm = &cm3232_pm_ops,
	#endif
	},
	.id_table = cm3232_id,
	.probe = cm3232_probe,
	.remove = cm3232_remove,
	};

	module_i2c_driver(cm3232_driver);

	MODULE_AUTHOR("Kevin Tsai <ktsai@capellamicro.com>");
	MODULE_DESCRIPTION("CM3232 ambient light sensor driver");
	MODULE_LICENSE("GPL");