drivers/iio/adc/ina2xx-adc.c - kernel/msm-4.19 - Gitiles

 /*
  * INA2XX Current and Power Monitors
  *
  * Copyright 2015 Baylibre SAS.
  *
  * 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.
  *
  * Based on linux/drivers/iio/adc/ad7291.c
  * Copyright 2010-2011 Analog Devices Inc.
  *
  * Based on linux/drivers/hwmon/ina2xx.c
  * Copyright 2012 Lothar Felten <l-felten@ti.com>
  *
  * Licensed under the GPL-2 or later.
  *
  * IIO driver for INA219-220-226-230-231
  *
  * Configurable 7-bit I2C slave address from 0x40 to 0x4F
  */

 #include <linux/delay.h>
 #include <linux/i2c.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/buffer.h>
 #include <linux/iio/kfifo_buf.h>
 #include <linux/iio/sysfs.h>
 #include <linux/kthread.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/regmap.h>
 #include <linux/util_macros.h>

 #include <linux/platform_data/ina2xx.h>

 /* INA2XX registers definition */
 #define INA2XX_CONFIG                   0x00
 #define INA2XX_SHUNT_VOLTAGE            0x01	/* readonly */
 #define INA2XX_BUS_VOLTAGE              0x02	/* readonly */
 #define INA2XX_POWER                    0x03	/* readonly */
 #define INA2XX_CURRENT                  0x04	/* readonly */
 #define INA2XX_CALIBRATION              0x05

 #define INA226_ALERT_MASK		GENMASK(2, 1)
 #define INA266_CVRF			BIT(3)

 #define INA2XX_MAX_REGISTERS            8

 /* settings - depend on use case */
 #define INA219_CONFIG_DEFAULT           0x399F	/* PGA=8 */
 #define INA226_CONFIG_DEFAULT           0x4327
 #define INA226_DEFAULT_AVG              4
 #define INA226_DEFAULT_IT		1110

 #define INA2XX_RSHUNT_DEFAULT           10000

 /*
  * bit mask for reading the averaging setting in the configuration register
  * FIXME: use regmap_fields.
  */
 #define INA2XX_MODE_MASK	GENMASK(3, 0)

 #define INA226_AVG_MASK		GENMASK(11, 9)
 #define INA226_SHIFT_AVG(val)	((val) << 9)

 /* Integration time for VBus */
 #define INA226_ITB_MASK		GENMASK(8, 6)
 #define INA226_SHIFT_ITB(val)	((val) << 6)

 /* Integration time for VShunt */
 #define INA226_ITS_MASK		GENMASK(5, 3)
 #define INA226_SHIFT_ITS(val)	((val) << 3)

 /* Cosmetic macro giving the sampling period for a full P=UxI cycle */
 #define SAMPLING_PERIOD(c)	((c->int_time_vbus + c->int_time_vshunt) \
 				 * c->avg)

 static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
 {
 	return (reg == INA2XX_CONFIG) || (reg > INA2XX_CURRENT);
 }

 static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
 {
 	return (reg != INA2XX_CONFIG);
 }

 static inline bool is_signed_reg(unsigned int reg)
 {
 	return (reg == INA2XX_SHUNT_VOLTAGE) || (reg == INA2XX_CURRENT);
 }

 static const struct regmap_config ina2xx_regmap_config = {
 	.reg_bits = 8,
 	.val_bits = 16,
 	.max_register = INA2XX_MAX_REGISTERS,
 	.writeable_reg = ina2xx_is_writeable_reg,
 	.volatile_reg = ina2xx_is_volatile_reg,
 };

 enum ina2xx_ids { ina219, ina226 };

 struct ina2xx_config {
 	u16 config_default;
 	int calibration_factor;
 	int shunt_div;
 	int bus_voltage_shift;
 	int bus_voltage_lsb;	/* uV */
 	int power_lsb;		/* uW */
 };

 struct ina2xx_chip_info {
 	struct regmap *regmap;
 	struct task_struct *task;
 	const struct ina2xx_config *config;
 	struct mutex state_lock;
 	unsigned int shunt_resistor;
 	int avg;
 	int int_time_vbus; /* Bus voltage integration time uS */
 	int int_time_vshunt; /* Shunt voltage integration time uS */
 	bool allow_async_readout;
 };

 static const struct ina2xx_config ina2xx_config[] = {
 	[ina219] = {
 		.config_default = INA219_CONFIG_DEFAULT,
 		.calibration_factor = 40960000,
 		.shunt_div = 100,
 		.bus_voltage_shift = 3,
 		.bus_voltage_lsb = 4000,
 		.power_lsb = 20000,
 	},
 	[ina226] = {
 		.config_default = INA226_CONFIG_DEFAULT,
 		.calibration_factor = 5120000,
 		.shunt_div = 400,
 		.bus_voltage_shift = 0,
 		.bus_voltage_lsb = 1250,
 		.power_lsb = 25000,
 	},
 };

 static int ina2xx_read_raw(struct iio_dev *indio_dev,
 			   struct iio_chan_spec const *chan,
 			   int *val, int *val2, long mask)
 {
 	int ret;
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 	unsigned int regval;

 	switch (mask) {
 	case IIO_CHAN_INFO_RAW:
 		ret = regmap_read(chip->regmap, chan->address, &regval);
 		if (ret)
 			return ret;

 		if (is_signed_reg(chan->address))
 			*val = (s16) regval;
 		else
 			*val  = regval;

 		return IIO_VAL_INT;

 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		*val = chip->avg;
 		return IIO_VAL_INT;

 	case IIO_CHAN_INFO_INT_TIME:
 		*val = 0;
 		if (chan->address == INA2XX_SHUNT_VOLTAGE)
 			*val2 = chip->int_time_vshunt;
 		else
 			*val2 = chip->int_time_vbus;

 		return IIO_VAL_INT_PLUS_MICRO;

 	case IIO_CHAN_INFO_SAMP_FREQ:
 		/*
 		 * Sample freq is read only, it is a consequence of
 		 * 1/AVG*(CT_bus+CT_shunt).
 		 */
 		*val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));

 		return IIO_VAL_INT;

 	case IIO_CHAN_INFO_SCALE:
 		switch (chan->address) {
 		case INA2XX_SHUNT_VOLTAGE:
 			/* processed (mV) = raw/shunt_div */
 			*val2 = chip->config->shunt_div;
 			*val = 1;
 			return IIO_VAL_FRACTIONAL;

 		case INA2XX_BUS_VOLTAGE:
 			/* processed (mV) = raw*lsb (uV) / (1000 << shift) */
 			*val = chip->config->bus_voltage_lsb;
 			*val2 = 1000 << chip->config->bus_voltage_shift;
 			return IIO_VAL_FRACTIONAL;

 		case INA2XX_POWER:
 			/* processed (mW) = raw*lsb (uW) / 1000 */
 			*val = chip->config->power_lsb;
 			*val2 = 1000;
 			return IIO_VAL_FRACTIONAL;

 		case INA2XX_CURRENT:
 			/* processed (mA) = raw (mA) */
 			*val = 1;
 			return IIO_VAL_INT;
 		}
 	}

 	return -EINVAL;
 }

 /*
  * Available averaging rates for ina226. The indices correspond with
  * the bit values expected by the chip (according to the ina226 datasheet,
  * table 3 AVG bit settings, found at
  * http://www.ti.com/lit/ds/symlink/ina226.pdf.
  */
 static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };

 static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
 			      unsigned int *config)
 {
 	int bits;

 	if (val > 1024 || val < 1)
 		return -EINVAL;

 	bits = find_closest(val, ina226_avg_tab,
 			    ARRAY_SIZE(ina226_avg_tab));

 	chip->avg = ina226_avg_tab[bits];

 	*config &= ~INA226_AVG_MASK;
 	*config |= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;

 	return 0;
 }

 /* Conversion times in uS */
 static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
 					    2116, 4156, 8244 };

 static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
 				    unsigned int val_us, unsigned int *config)
 {
 	int bits;

 	if (val_us > 8244 || val_us < 140)
 		return -EINVAL;

 	bits = find_closest(val_us, ina226_conv_time_tab,
 			    ARRAY_SIZE(ina226_conv_time_tab));

 	chip->int_time_vbus = ina226_conv_time_tab[bits];

 	*config &= ~INA226_ITB_MASK;
 	*config |= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;

 	return 0;
 }

 static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
 				      unsigned int val_us, unsigned int *config)
 {
 	int bits;

 	if (val_us > 8244 || val_us < 140)
 		return -EINVAL;

 	bits = find_closest(val_us, ina226_conv_time_tab,
 			    ARRAY_SIZE(ina226_conv_time_tab));

 	chip->int_time_vshunt = ina226_conv_time_tab[bits];

 	*config &= ~INA226_ITS_MASK;
 	*config |= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;

 	return 0;
 }

 static int ina2xx_write_raw(struct iio_dev *indio_dev,
 			    struct iio_chan_spec const *chan,
 			    int val, int val2, long mask)
 {
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 	unsigned int config, tmp;
 	int ret;

 	if (iio_buffer_enabled(indio_dev))
 		return -EBUSY;

 	mutex_lock(&chip->state_lock);

 	ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
 	if (ret)
 		goto err;

 	tmp = config;

 	switch (mask) {
 	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
 		ret = ina226_set_average(chip, val, &tmp);
 		break;

 	case IIO_CHAN_INFO_INT_TIME:
 		if (chan->address == INA2XX_SHUNT_VOLTAGE)
 			ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
 		else
 			ret = ina226_set_int_time_vbus(chip, val2, &tmp);
 		break;

 	default:
 		ret = -EINVAL;
 	}

 	if (!ret && (tmp != config))
 		ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
 err:
 	mutex_unlock(&chip->state_lock);

 	return ret;
 }

 static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
 					   struct device_attribute *attr,
 					   char *buf)
 {
 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));

 	return sprintf(buf, "%d\n", chip->allow_async_readout);
 }

 static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
 				struct device_attribute *attr,
 				const char *buf, size_t len)
 {
 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 	bool val;
 	int ret;

 	ret = strtobool((const char *) buf, &val);
 	if (ret)
 		return ret;

 	chip->allow_async_readout = val;

 	return len;
 }

 /*
  * Set current LSB to 1mA, shunt is in uOhms
  * (equation 13 in datasheet). We hardcode a Current_LSB
  * of 1.0 x10-6. The only remaining parameter is RShunt.
  * There is no need to expose the CALIBRATION register
  * to the user for now. But we need to reset this register
  * if the user updates RShunt after driver init, e.g upon
  * reading an EEPROM/Probe-type value.
  */
 static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
 {
 	u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
 				   chip->shunt_resistor);

 	return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
 }

 static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
 {
 	if (val <= 0 || val > chip->config->calibration_factor)
 		return -EINVAL;

 	chip->shunt_resistor = val;

 	return 0;
 }

 static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
 					  struct device_attribute *attr,
 					  char *buf)
 {
 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));

 	return sprintf(buf, "%d\n", chip->shunt_resistor);
 }

 static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
 					   struct device_attribute *attr,
 					   const char *buf, size_t len)
 {
 	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
 	unsigned long val;
 	int ret;

 	ret = kstrtoul((const char *) buf, 10, &val);
 	if (ret)
 		return ret;

 	ret = set_shunt_resistor(chip, val);
 	if (ret)
 		return ret;

 	/* Update the Calibration register */
 	ret = ina2xx_set_calibration(chip);
 	if (ret)
 		return ret;

 	return len;
 }

 #define INA2XX_CHAN(_type, _index, _address) { \
 	.type = (_type), \
 	.address = (_address), \
 	.indexed = 1, \
 	.channel = (_index), \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
 	| BIT(IIO_CHAN_INFO_SCALE), \
 	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
 				   BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
 	.scan_index = (_index), \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = 16, \
 		.storagebits = 16, \
 		.endianness = IIO_CPU, \
 	} \
 }

 /*
  * Sampling Freq is a consequence of the integration times of
  * the Voltage channels.
  */
 #define INA2XX_CHAN_VOLTAGE(_index, _address) { \
 	.type = IIO_VOLTAGE, \
 	.address = (_address), \
 	.indexed = 1, \
 	.channel = (_index), \
 	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
 			      BIT(IIO_CHAN_INFO_SCALE) | \
 			      BIT(IIO_CHAN_INFO_INT_TIME), \
 	.scan_index = (_index), \
 	.scan_type = { \
 		.sign = 'u', \
 		.realbits = 16, \
 		.storagebits = 16, \
 		.endianness = IIO_LE, \
 	} \
 }

 static const struct iio_chan_spec ina2xx_channels[] = {
 	INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
 	INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
 	INA2XX_CHAN(IIO_POWER, 2, INA2XX_POWER),
 	INA2XX_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
 	IIO_CHAN_SOFT_TIMESTAMP(4),
 };

 static int ina2xx_work_buffer(struct iio_dev *indio_dev)
 {
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 	unsigned short data[8];
 	int bit, ret, i = 0;
 	s64 time_a, time_b;
 	unsigned int alert;

 	time_a = iio_get_time_ns(indio_dev);

 	/*
 	 * Because the timer thread and the chip conversion clock
 	 * are asynchronous, the period difference will eventually
 	 * result in reading V[k-1] again, or skip V[k] at time Tk.
 	 * In order to resync the timer with the conversion process
 	 * we check the ConVersionReadyFlag.
 	 * On hardware that supports using the ALERT pin to toggle a
 	 * GPIO a triggered buffer could be used instead.
 	 * For now, we pay for that extra read of the ALERT register
 	 */
 	if (!chip->allow_async_readout)
 		do {
 			ret = regmap_read(chip->regmap, INA226_ALERT_MASK,
 					  &alert);
 			if (ret < 0)
 				return ret;

 			alert &= INA266_CVRF;
 		} while (!alert);

 	/*
 	 * Single register reads: bulk_read will not work with ina226
 	 * as there is no auto-increment of the address register for
 	 * data length longer than 16bits.
 	 */
 	for_each_set_bit(bit, indio_dev->active_scan_mask,
 			 indio_dev->masklength) {
 		unsigned int val;

 		ret = regmap_read(chip->regmap,
 				  INA2XX_SHUNT_VOLTAGE + bit, &val);
 		if (ret < 0)
 			return ret;

 		data[i++] = val;
 	}

 	time_b = iio_get_time_ns(indio_dev);

 	iio_push_to_buffers_with_timestamp(indio_dev,
 					   (unsigned int *)data, time_a);

 	return (unsigned long)(time_b - time_a) / 1000;
 };

 static int ina2xx_capture_thread(void *data)
 {
 	struct iio_dev *indio_dev = data;
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 	unsigned int sampling_us = SAMPLING_PERIOD(chip);
 	int buffer_us;

 	/*
 	 * Poll a bit faster than the chip internal Fs, in case
 	 * we wish to sync with the conversion ready flag.
 	 */
 	if (!chip->allow_async_readout)
 		sampling_us -= 200;

 	do {
 		buffer_us = ina2xx_work_buffer(indio_dev);
 		if (buffer_us < 0)
 			return buffer_us;

 		if (sampling_us > buffer_us)
 			udelay(sampling_us - buffer_us);

 	} while (!kthread_should_stop());

 	return 0;
 }

 static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
 {
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
 	unsigned int sampling_us = SAMPLING_PERIOD(chip);

 	dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
 		(unsigned int)(*indio_dev->active_scan_mask),
 		1000000 / sampling_us, chip->avg);

 	dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
 	dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
 		chip->allow_async_readout);

 	chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
 				 "%s:%d-%uus", indio_dev->name, indio_dev->id,
 				 sampling_us);

 	return PTR_ERR_OR_ZERO(chip->task);
 }

 static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
 {
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);

 	if (chip->task) {
 		kthread_stop(chip->task);
 		chip->task = NULL;
 	}

 	return 0;
 }

 static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
 	.postenable = &ina2xx_buffer_enable,
 	.predisable = &ina2xx_buffer_disable,
 };

 static int ina2xx_debug_reg(struct iio_dev *indio_dev,
 			    unsigned reg, unsigned writeval, unsigned *readval)
 {
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);

 	if (!readval)
 		return regmap_write(chip->regmap, reg, writeval);

 	return regmap_read(chip->regmap, reg, readval);
 }

 /* Possible integration times for vshunt and vbus */
 static IIO_CONST_ATTR_INT_TIME_AVAIL("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");

 static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO | S_IWUSR,
 		       ina2xx_allow_async_readout_show,
 		       ina2xx_allow_async_readout_store, 0);

 static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO | S_IWUSR,
 		       ina2xx_shunt_resistor_show,
 		       ina2xx_shunt_resistor_store, 0);

 static struct attribute *ina2xx_attributes[] = {
 	&iio_dev_attr_in_allow_async_readout.dev_attr.attr,
 	&iio_const_attr_integration_time_available.dev_attr.attr,
 	&iio_dev_attr_in_shunt_resistor.dev_attr.attr,
 	NULL,
 };

 static const struct attribute_group ina2xx_attribute_group = {
 	.attrs = ina2xx_attributes,
 };

 static const struct iio_info ina2xx_info = {
 	.driver_module = THIS_MODULE,
 	.attrs = &ina2xx_attribute_group,
 	.read_raw = ina2xx_read_raw,
 	.write_raw = ina2xx_write_raw,
 	.debugfs_reg_access = ina2xx_debug_reg,
 };

 /* Initialize the configuration and calibration registers. */
 static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
 {
 	int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
 	if (ret)
 		return ret;

 	return ina2xx_set_calibration(chip);
 }

 static int ina2xx_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	struct ina2xx_chip_info *chip;
 	struct iio_dev *indio_dev;
 	struct iio_buffer *buffer;
 	unsigned int val;
 	enum ina2xx_ids type;
 	int ret;

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

 	chip = iio_priv(indio_dev);

 	/* This is only used for device removal purposes. */
 	i2c_set_clientdata(client, indio_dev);

 	chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 	if (IS_ERR(chip->regmap)) {
 		dev_err(&client->dev, "failed to allocate register map\n");
 		return PTR_ERR(chip->regmap);
 	}

 	if (client->dev.of_node)
 		type = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
 	else
 		type = id->driver_data;
 	chip->config = &ina2xx_config[type];

 	mutex_init(&chip->state_lock);

 	if (of_property_read_u32(client->dev.of_node,
 				 "shunt-resistor", &val) < 0) {
 		struct ina2xx_platform_data *pdata =
 		    dev_get_platdata(&client->dev);

 		if (pdata)
 			val = pdata->shunt_uohms;
 		else
 			val = INA2XX_RSHUNT_DEFAULT;
 	}

 	ret = set_shunt_resistor(chip, val);
 	if (ret)
 		return ret;

 	/* Patch the current config register with default. */
 	val = chip->config->config_default;

 	if (id->driver_data == ina226) {
 		ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
 		ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
 		ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
 	}

 	ret = ina2xx_init(chip, val);
 	if (ret) {
 		dev_err(&client->dev, "error configuring the device\n");
 		return ret;
 	}

 	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
 	indio_dev->dev.parent = &client->dev;
 	indio_dev->dev.of_node = client->dev.of_node;
 	indio_dev->channels = ina2xx_channels;
 	indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
 	indio_dev->name = id->name;
 	indio_dev->info = &ina2xx_info;
 	indio_dev->setup_ops = &ina2xx_setup_ops;

 	buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
 	if (!buffer)
 		return -ENOMEM;

 	iio_device_attach_buffer(indio_dev, buffer);

 	return iio_device_register(indio_dev);
 }

 static int ina2xx_remove(struct i2c_client *client)
 {
 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
 	struct ina2xx_chip_info *chip = iio_priv(indio_dev);

 	iio_device_unregister(indio_dev);

 	/* Powerdown */
 	return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
 				  INA2XX_MODE_MASK, 0);
 }

 static const struct i2c_device_id ina2xx_id[] = {
 	{"ina219", ina219},
 	{"ina220", ina219},
 	{"ina226", ina226},
 	{"ina230", ina226},
 	{"ina231", ina226},
 	{}
 };
 MODULE_DEVICE_TABLE(i2c, ina2xx_id);

 static const struct of_device_id ina2xx_of_match[] = {
 	{
 		.compatible = "ti,ina219",
 		.data = (void *)ina219
 	},
 	{
 		.compatible = "ti,ina220",
 		.data = (void *)ina219
 	},
 	{
 		.compatible = "ti,ina226",
 		.data = (void *)ina226
 	},
 	{
 		.compatible = "ti,ina230",
 		.data = (void *)ina226
 	},
 	{
 		.compatible = "ti,ina231",
 		.data = (void *)ina226
 	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, ina2xx_of_match);

 static struct i2c_driver ina2xx_driver = {
 	.driver = {
 		   .name = KBUILD_MODNAME,
 		   .of_match_table = ina2xx_of_match,
 	},
 	.probe = ina2xx_probe,
 	.remove = ina2xx_remove,
 	.id_table = ina2xx_id,
 };
 module_i2c_driver(ina2xx_driver);

 MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
 MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
 MODULE_LICENSE("GPL v2");
	/*
	* INA2XX Current and Power Monitors
	*
	* Copyright 2015 Baylibre SAS.
	*
	* 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.
	*
	* Based on linux/drivers/iio/adc/ad7291.c
	* Copyright 2010-2011 Analog Devices Inc.
	*
	* Based on linux/drivers/hwmon/ina2xx.c
	* Copyright 2012 Lothar Felten <l-felten@ti.com>
	*
	* Licensed under the GPL-2 or later.
	*
	* IIO driver for INA219-220-226-230-231
	*
	* Configurable 7-bit I2C slave address from 0x40 to 0x4F
	*/

	#include <linux/delay.h>
	#include <linux/i2c.h>
	#include <linux/iio/iio.h>
	#include <linux/iio/buffer.h>
	#include <linux/iio/kfifo_buf.h>
	#include <linux/iio/sysfs.h>
	#include <linux/kthread.h>
	#include <linux/module.h>
	#include <linux/of_device.h>
	#include <linux/regmap.h>
	#include <linux/util_macros.h>

	#include <linux/platform_data/ina2xx.h>

	/* INA2XX registers definition */
	#define INA2XX_CONFIG 0x00
	#define INA2XX_SHUNT_VOLTAGE 0x01 /* readonly */
	#define INA2XX_BUS_VOLTAGE 0x02 /* readonly */
	#define INA2XX_POWER 0x03 /* readonly */
	#define INA2XX_CURRENT 0x04 /* readonly */
	#define INA2XX_CALIBRATION 0x05

	#define INA226_ALERT_MASK GENMASK(2, 1)
	#define INA266_CVRF BIT(3)

	#define INA2XX_MAX_REGISTERS 8

	/* settings - depend on use case */
	#define INA219_CONFIG_DEFAULT 0x399F /* PGA=8 */
	#define INA226_CONFIG_DEFAULT 0x4327
	#define INA226_DEFAULT_AVG 4
	#define INA226_DEFAULT_IT 1110

	#define INA2XX_RSHUNT_DEFAULT 10000

	/*
	* bit mask for reading the averaging setting in the configuration register
	* FIXME: use regmap_fields.
	*/
	#define INA2XX_MODE_MASK GENMASK(3, 0)

	#define INA226_AVG_MASK GENMASK(11, 9)
	#define INA226_SHIFT_AVG(val) ((val) << 9)

	/* Integration time for VBus */
	#define INA226_ITB_MASK GENMASK(8, 6)
	#define INA226_SHIFT_ITB(val) ((val) << 6)

	/* Integration time for VShunt */
	#define INA226_ITS_MASK GENMASK(5, 3)
	#define INA226_SHIFT_ITS(val) ((val) << 3)

	/* Cosmetic macro giving the sampling period for a full P=UxI cycle */
	#define SAMPLING_PERIOD(c) ((c->int_time_vbus + c->int_time_vshunt) \
	* c->avg)

	static bool ina2xx_is_writeable_reg(struct device *dev, unsigned int reg)
	{
	return (reg == INA2XX_CONFIG) \|\| (reg > INA2XX_CURRENT);
	}

	static bool ina2xx_is_volatile_reg(struct device *dev, unsigned int reg)
	{
	return (reg != INA2XX_CONFIG);
	}

	static inline bool is_signed_reg(unsigned int reg)
	{
	return (reg == INA2XX_SHUNT_VOLTAGE) \|\| (reg == INA2XX_CURRENT);
	}

	static const struct regmap_config ina2xx_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
	.max_register = INA2XX_MAX_REGISTERS,
	.writeable_reg = ina2xx_is_writeable_reg,
	.volatile_reg = ina2xx_is_volatile_reg,
	};

	enum ina2xx_ids { ina219, ina226 };

	struct ina2xx_config {
	u16 config_default;
	int calibration_factor;
	int shunt_div;
	int bus_voltage_shift;
	int bus_voltage_lsb; /* uV */
	int power_lsb; /* uW */
	};

	struct ina2xx_chip_info {
	struct regmap *regmap;
	struct task_struct *task;
	const struct ina2xx_config *config;
	struct mutex state_lock;
	unsigned int shunt_resistor;
	int avg;
	int int_time_vbus; /* Bus voltage integration time uS */
	int int_time_vshunt; /* Shunt voltage integration time uS */
	bool allow_async_readout;
	};

	static const struct ina2xx_config ina2xx_config[] = {
	[ina219] = {
	.config_default = INA219_CONFIG_DEFAULT,
	.calibration_factor = 40960000,
	.shunt_div = 100,
	.bus_voltage_shift = 3,
	.bus_voltage_lsb = 4000,
	.power_lsb = 20000,
	},
	[ina226] = {
	.config_default = INA226_CONFIG_DEFAULT,
	.calibration_factor = 5120000,
	.shunt_div = 400,
	.bus_voltage_shift = 0,
	.bus_voltage_lsb = 1250,
	.power_lsb = 25000,
	},
	};

	static int ina2xx_read_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	int ret;
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
	unsigned int regval;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
	ret = regmap_read(chip->regmap, chan->address, &regval);
	if (ret)
	return ret;

	if (is_signed_reg(chan->address))
	*val = (s16) regval;
	else
	*val = regval;

	return IIO_VAL_INT;

	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
	*val = chip->avg;
	return IIO_VAL_INT;

	case IIO_CHAN_INFO_INT_TIME:
	*val = 0;
	if (chan->address == INA2XX_SHUNT_VOLTAGE)
	*val2 = chip->int_time_vshunt;
	else
	*val2 = chip->int_time_vbus;

	return IIO_VAL_INT_PLUS_MICRO;

	case IIO_CHAN_INFO_SAMP_FREQ:
	/*
	* Sample freq is read only, it is a consequence of
	* 1/AVG*(CT_bus+CT_shunt).
	*/
	*val = DIV_ROUND_CLOSEST(1000000, SAMPLING_PERIOD(chip));

	return IIO_VAL_INT;

	case IIO_CHAN_INFO_SCALE:
	switch (chan->address) {
	case INA2XX_SHUNT_VOLTAGE:
	/* processed (mV) = raw/shunt_div */
	*val2 = chip->config->shunt_div;
	*val = 1;
	return IIO_VAL_FRACTIONAL;

	case INA2XX_BUS_VOLTAGE:
	/* processed (mV) = rawlsb (uV) / (1000 << shift) /
	*val = chip->config->bus_voltage_lsb;
	*val2 = 1000 << chip->config->bus_voltage_shift;
	return IIO_VAL_FRACTIONAL;

	case INA2XX_POWER:
	/* processed (mW) = rawlsb (uW) / 1000 /
	*val = chip->config->power_lsb;
	*val2 = 1000;
	return IIO_VAL_FRACTIONAL;

	case INA2XX_CURRENT:
	/* processed (mA) = raw (mA) */
	*val = 1;
	return IIO_VAL_INT;
	}
	}

	return -EINVAL;
	}

	/*
	* Available averaging rates for ina226. The indices correspond with
	* the bit values expected by the chip (according to the ina226 datasheet,
	* table 3 AVG bit settings, found at
	* http://www.ti.com/lit/ds/symlink/ina226.pdf.
	*/
	static const int ina226_avg_tab[] = { 1, 4, 16, 64, 128, 256, 512, 1024 };

	static int ina226_set_average(struct ina2xx_chip_info *chip, unsigned int val,
	unsigned int *config)
	{
	int bits;

	if (val > 1024 \|\| val < 1)
	return -EINVAL;

	bits = find_closest(val, ina226_avg_tab,
	ARRAY_SIZE(ina226_avg_tab));

	chip->avg = ina226_avg_tab[bits];

	*config &= ~INA226_AVG_MASK;
	*config \|= INA226_SHIFT_AVG(bits) & INA226_AVG_MASK;

	return 0;
	}

	/* Conversion times in uS */
	static const int ina226_conv_time_tab[] = { 140, 204, 332, 588, 1100,
	2116, 4156, 8244 };

	static int ina226_set_int_time_vbus(struct ina2xx_chip_info *chip,
	unsigned int val_us, unsigned int *config)
	{
	int bits;

	if (val_us > 8244 \|\| val_us < 140)
	return -EINVAL;

	bits = find_closest(val_us, ina226_conv_time_tab,
	ARRAY_SIZE(ina226_conv_time_tab));

	chip->int_time_vbus = ina226_conv_time_tab[bits];

	*config &= ~INA226_ITB_MASK;
	*config \|= INA226_SHIFT_ITB(bits) & INA226_ITB_MASK;

	return 0;
	}

	static int ina226_set_int_time_vshunt(struct ina2xx_chip_info *chip,
	unsigned int val_us, unsigned int *config)
	{
	int bits;

	if (val_us > 8244 \|\| val_us < 140)
	return -EINVAL;

	bits = find_closest(val_us, ina226_conv_time_tab,
	ARRAY_SIZE(ina226_conv_time_tab));

	chip->int_time_vshunt = ina226_conv_time_tab[bits];

	*config &= ~INA226_ITS_MASK;
	*config \|= INA226_SHIFT_ITS(bits) & INA226_ITS_MASK;

	return 0;
	}

	static int ina2xx_write_raw(struct iio_dev *indio_dev,
	struct iio_chan_spec const *chan,
	int val, int val2, long mask)
	{
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
	unsigned int config, tmp;
	int ret;

	if (iio_buffer_enabled(indio_dev))
	return -EBUSY;

	mutex_lock(&chip->state_lock);

	ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
	if (ret)
	goto err;

	tmp = config;

	switch (mask) {
	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
	ret = ina226_set_average(chip, val, &tmp);
	break;

	case IIO_CHAN_INFO_INT_TIME:
	if (chan->address == INA2XX_SHUNT_VOLTAGE)
	ret = ina226_set_int_time_vshunt(chip, val2, &tmp);
	else
	ret = ina226_set_int_time_vbus(chip, val2, &tmp);
	break;

	default:
	ret = -EINVAL;
	}

	if (!ret && (tmp != config))
	ret = regmap_write(chip->regmap, INA2XX_CONFIG, tmp);
	err:
	mutex_unlock(&chip->state_lock);

	return ret;
	}

	static ssize_t ina2xx_allow_async_readout_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));

	return sprintf(buf, "%d\n", chip->allow_async_readout);
	}

	static ssize_t ina2xx_allow_async_readout_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t len)
	{
	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
	bool val;
	int ret;

	ret = strtobool((const char *) buf, &val);
	if (ret)
	return ret;

	chip->allow_async_readout = val;

	return len;
	}

	/*
	* Set current LSB to 1mA, shunt is in uOhms
	* (equation 13 in datasheet). We hardcode a Current_LSB
	* of 1.0 x10-6. The only remaining parameter is RShunt.
	* There is no need to expose the CALIBRATION register
	* to the user for now. But we need to reset this register
	* if the user updates RShunt after driver init, e.g upon
	* reading an EEPROM/Probe-type value.
	*/
	static int ina2xx_set_calibration(struct ina2xx_chip_info *chip)
	{
	u16 regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
	chip->shunt_resistor);

	return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
	}

	static int set_shunt_resistor(struct ina2xx_chip_info *chip, unsigned int val)
	{
	if (val <= 0 \|\| val > chip->config->calibration_factor)
	return -EINVAL;

	chip->shunt_resistor = val;

	return 0;
	}

	static ssize_t ina2xx_shunt_resistor_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));

	return sprintf(buf, "%d\n", chip->shunt_resistor);
	}

	static ssize_t ina2xx_shunt_resistor_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t len)
	{
	struct ina2xx_chip_info *chip = iio_priv(dev_to_iio_dev(dev));
	unsigned long val;
	int ret;

	ret = kstrtoul((const char *) buf, 10, &val);
	if (ret)
	return ret;

	ret = set_shunt_resistor(chip, val);
	if (ret)
	return ret;

	/* Update the Calibration register */
	ret = ina2xx_set_calibration(chip);
	if (ret)
	return ret;

	return len;
	}

	#define INA2XX_CHAN(_type, _index, _address) { \
	.type = (_type), \
	.address = (_address), \
	.indexed = 1, \
	.channel = (_index), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \
	\| BIT(IIO_CHAN_INFO_SCALE), \
	.info_mask_shared_by_dir = BIT(IIO_CHAN_INFO_SAMP_FREQ) \| \
	BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \
	.scan_index = (_index), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = 16, \
	.storagebits = 16, \
	.endianness = IIO_CPU, \
	} \
	}

	/*
	* Sampling Freq is a consequence of the integration times of
	* the Voltage channels.
	*/
	#define INA2XX_CHAN_VOLTAGE(_index, _address) { \
	.type = IIO_VOLTAGE, \
	.address = (_address), \
	.indexed = 1, \
	.channel = (_index), \
	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) \| \
	BIT(IIO_CHAN_INFO_SCALE) \| \
	BIT(IIO_CHAN_INFO_INT_TIME), \
	.scan_index = (_index), \
	.scan_type = { \
	.sign = 'u', \
	.realbits = 16, \
	.storagebits = 16, \
	.endianness = IIO_LE, \
	} \
	}

	static const struct iio_chan_spec ina2xx_channels[] = {
	INA2XX_CHAN_VOLTAGE(0, INA2XX_SHUNT_VOLTAGE),
	INA2XX_CHAN_VOLTAGE(1, INA2XX_BUS_VOLTAGE),
	INA2XX_CHAN(IIO_POWER, 2, INA2XX_POWER),
	INA2XX_CHAN(IIO_CURRENT, 3, INA2XX_CURRENT),
	IIO_CHAN_SOFT_TIMESTAMP(4),
	};

	static int ina2xx_work_buffer(struct iio_dev *indio_dev)
	{
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
	unsigned short data[8];
	int bit, ret, i = 0;
	s64 time_a, time_b;
	unsigned int alert;

	time_a = iio_get_time_ns(indio_dev);

	/*
	* Because the timer thread and the chip conversion clock
	* are asynchronous, the period difference will eventually
	* result in reading V[k-1] again, or skip V[k] at time Tk.
	* In order to resync the timer with the conversion process
	* we check the ConVersionReadyFlag.
	* On hardware that supports using the ALERT pin to toggle a
	* GPIO a triggered buffer could be used instead.
	* For now, we pay for that extra read of the ALERT register
	*/
	if (!chip->allow_async_readout)
	do {
	ret = regmap_read(chip->regmap, INA226_ALERT_MASK,
	&alert);
	if (ret < 0)
	return ret;

	alert &= INA266_CVRF;
	} while (!alert);

	/*
	* Single register reads: bulk_read will not work with ina226
	* as there is no auto-increment of the address register for
	* data length longer than 16bits.
	*/
	for_each_set_bit(bit, indio_dev->active_scan_mask,
	indio_dev->masklength) {
	unsigned int val;

	ret = regmap_read(chip->regmap,
	INA2XX_SHUNT_VOLTAGE + bit, &val);
	if (ret < 0)
	return ret;

	data[i++] = val;
	}

	time_b = iio_get_time_ns(indio_dev);

	iio_push_to_buffers_with_timestamp(indio_dev,
	(unsigned int *)data, time_a);

	return (unsigned long)(time_b - time_a) / 1000;
	};

	static int ina2xx_capture_thread(void *data)
	{
	struct iio_dev *indio_dev = data;
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
	unsigned int sampling_us = SAMPLING_PERIOD(chip);
	int buffer_us;

	/*
	* Poll a bit faster than the chip internal Fs, in case
	* we wish to sync with the conversion ready flag.
	*/
	if (!chip->allow_async_readout)
	sampling_us -= 200;

	do {
	buffer_us = ina2xx_work_buffer(indio_dev);
	if (buffer_us < 0)
	return buffer_us;

	if (sampling_us > buffer_us)
	udelay(sampling_us - buffer_us);

	} while (!kthread_should_stop());

	return 0;
	}

	static int ina2xx_buffer_enable(struct iio_dev *indio_dev)
	{
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);
	unsigned int sampling_us = SAMPLING_PERIOD(chip);

	dev_dbg(&indio_dev->dev, "Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
	(unsigned int)(*indio_dev->active_scan_mask),
	1000000 / sampling_us, chip->avg);

	dev_dbg(&indio_dev->dev, "Expected work period: %u us\n", sampling_us);
	dev_dbg(&indio_dev->dev, "Async readout mode: %d\n",
	chip->allow_async_readout);

	chip->task = kthread_run(ina2xx_capture_thread, (void *)indio_dev,
	"%s:%d-%uus", indio_dev->name, indio_dev->id,
	sampling_us);

	return PTR_ERR_OR_ZERO(chip->task);
	}

	static int ina2xx_buffer_disable(struct iio_dev *indio_dev)
	{
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);

	if (chip->task) {
	kthread_stop(chip->task);
	chip->task = NULL;
	}

	return 0;
	}

	static const struct iio_buffer_setup_ops ina2xx_setup_ops = {
	.postenable = &ina2xx_buffer_enable,
	.predisable = &ina2xx_buffer_disable,
	};

	static int ina2xx_debug_reg(struct iio_dev *indio_dev,
	unsigned reg, unsigned writeval, unsigned *readval)
	{
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);

	if (!readval)
	return regmap_write(chip->regmap, reg, writeval);

	return regmap_read(chip->regmap, reg, readval);
	}

	/* Possible integration times for vshunt and vbus */
	static IIO_CONST_ATTR_INT_TIME_AVAIL("0.000140 0.000204 0.000332 0.000588 0.001100 0.002116 0.004156 0.008244");

	static IIO_DEVICE_ATTR(in_allow_async_readout, S_IRUGO \| S_IWUSR,
	ina2xx_allow_async_readout_show,
	ina2xx_allow_async_readout_store, 0);

	static IIO_DEVICE_ATTR(in_shunt_resistor, S_IRUGO \| S_IWUSR,
	ina2xx_shunt_resistor_show,
	ina2xx_shunt_resistor_store, 0);

	static struct attribute *ina2xx_attributes[] = {
	&iio_dev_attr_in_allow_async_readout.dev_attr.attr,
	&iio_const_attr_integration_time_available.dev_attr.attr,
	&iio_dev_attr_in_shunt_resistor.dev_attr.attr,
	NULL,
	};

	static const struct attribute_group ina2xx_attribute_group = {
	.attrs = ina2xx_attributes,
	};

	static const struct iio_info ina2xx_info = {
	.driver_module = THIS_MODULE,
	.attrs = &ina2xx_attribute_group,
	.read_raw = ina2xx_read_raw,
	.write_raw = ina2xx_write_raw,
	.debugfs_reg_access = ina2xx_debug_reg,
	};

	/* Initialize the configuration and calibration registers. */
	static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
	{
	int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
	if (ret)
	return ret;

	return ina2xx_set_calibration(chip);
	}

	static int ina2xx_probe(struct i2c_client *client,
	const struct i2c_device_id *id)
	{
	struct ina2xx_chip_info *chip;
	struct iio_dev *indio_dev;
	struct iio_buffer *buffer;
	unsigned int val;
	enum ina2xx_ids type;
	int ret;

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

	chip = iio_priv(indio_dev);

	/* This is only used for device removal purposes. */
	i2c_set_clientdata(client, indio_dev);

	chip->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
	if (IS_ERR(chip->regmap)) {
	dev_err(&client->dev, "failed to allocate register map\n");
	return PTR_ERR(chip->regmap);
	}

	if (client->dev.of_node)
	type = (enum ina2xx_ids)of_device_get_match_data(&client->dev);
	else
	type = id->driver_data;
	chip->config = &ina2xx_config[type];

	mutex_init(&chip->state_lock);

	if (of_property_read_u32(client->dev.of_node,
	"shunt-resistor", &val) < 0) {
	struct ina2xx_platform_data *pdata =
	dev_get_platdata(&client->dev);

	if (pdata)
	val = pdata->shunt_uohms;
	else
	val = INA2XX_RSHUNT_DEFAULT;
	}

	ret = set_shunt_resistor(chip, val);
	if (ret)
	return ret;

	/* Patch the current config register with default. */
	val = chip->config->config_default;

	if (id->driver_data == ina226) {
	ina226_set_average(chip, INA226_DEFAULT_AVG, &val);
	ina226_set_int_time_vbus(chip, INA226_DEFAULT_IT, &val);
	ina226_set_int_time_vshunt(chip, INA226_DEFAULT_IT, &val);
	}

	ret = ina2xx_init(chip, val);
	if (ret) {
	dev_err(&client->dev, "error configuring the device\n");
	return ret;
	}

	indio_dev->modes = INDIO_DIRECT_MODE \| INDIO_BUFFER_SOFTWARE;
	indio_dev->dev.parent = &client->dev;
	indio_dev->dev.of_node = client->dev.of_node;
	indio_dev->channels = ina2xx_channels;
	indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
	indio_dev->name = id->name;
	indio_dev->info = &ina2xx_info;
	indio_dev->setup_ops = &ina2xx_setup_ops;

	buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
	if (!buffer)
	return -ENOMEM;

	iio_device_attach_buffer(indio_dev, buffer);

	return iio_device_register(indio_dev);
	}

	static int ina2xx_remove(struct i2c_client *client)
	{
	struct iio_dev *indio_dev = i2c_get_clientdata(client);
	struct ina2xx_chip_info *chip = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);

	/* Powerdown */
	return regmap_update_bits(chip->regmap, INA2XX_CONFIG,
	INA2XX_MODE_MASK, 0);
	}

	static const struct i2c_device_id ina2xx_id[] = {
	{"ina219", ina219},
	{"ina220", ina219},
	{"ina226", ina226},
	{"ina230", ina226},
	{"ina231", ina226},
	{}
	};
	MODULE_DEVICE_TABLE(i2c, ina2xx_id);

	static const struct of_device_id ina2xx_of_match[] = {
	{
	.compatible = "ti,ina219",
	.data = (void *)ina219
	},
	{
	.compatible = "ti,ina220",
	.data = (void *)ina219
	},
	{
	.compatible = "ti,ina226",
	.data = (void *)ina226
	},
	{
	.compatible = "ti,ina230",
	.data = (void *)ina226
	},
	{
	.compatible = "ti,ina231",
	.data = (void *)ina226
	},
	{},
	};
	MODULE_DEVICE_TABLE(of, ina2xx_of_match);

	static struct i2c_driver ina2xx_driver = {
	.driver = {
	.name = KBUILD_MODNAME,
	.of_match_table = ina2xx_of_match,
	},
	.probe = ina2xx_probe,
	.remove = ina2xx_remove,
	.id_table = ina2xx_id,
	};
	module_i2c_driver(ina2xx_driver);

	MODULE_AUTHOR("Marc Titinger <marc.titinger@baylibre.com>");
	MODULE_DESCRIPTION("Texas Instruments INA2XX ADC driver");
	MODULE_LICENSE("GPL v2");