Merge tag 'iio-for-4.5b' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

Second set of IIO new drivers, functionality and cleanups for the 4.5 cycle.

The big one here is the configfs support which has been a long time in the
works but should allow for cleaner ways to do instantiation of those elements
of IIO that aren't directly connected to specific hardware. Lots of cool new
stuff we can use this for in the works!

New core stuff (basically all configfs support related)
* Configfs support
  - Core support (was waiting for a configfs patch that went in around 4.4rc2)
  - A little fixlet to add a configfs.h to contain a reference to the
    configfs_subsystem structure.
* Some infrastructure to simplify handling of software based triggers
  (i.e. ones with no actual hardware associated with them)
* A high resolution timer based trigger.  This has been around for years
    but until the configfs support was ready we didn't have a sensible way
    of instantiating instances of it (the method used for the sysfs_trigger
    has never been really satisfactory)

New Device Support
* AMS iAQ Volatile Organic Compounds sensor support.
* Freescale imx7d ADC driver
* Maxim MAX30100 oximeter driver (note that for these devices most of the
  smart stuff will be in userspace - effectively they are just light sensors
  with some interesting led synchronization as far as the kernel is concerned).
* Microchip mcp3421 support added to the mcp3422 driver.
* TI adc124s021 support added to the adc128s052 driver.
* TI ina219, inda226 power monitors. Note that there is an existing hwmon driver
  for these parts, the usecase is somewhat different so it is unclear at this
  point if the hwmon driver will eventually be replaced by a bridge from
  this driver.  In the meantime the Kconfig dependencies should prevent both
  from being built.

New driver functionality
* us8152d power management support.

Cleanups, fixups
* Use list_for_each_entry_safe instead of list_for_each_safe with the entry
  bit coded longhand.
* Select IRQ_WORK for IIO_DUMMY_EVGEN.  This is a fix that somehow got lost
  when the driver was moved so lets do it again.
* st-accel - drop an unused define.
* vz89x, lidar - optimize i2c transactions by using a single i2c tranfers
  instead of multiple calls where supported (fall back to smbus calls as
  before if not).
* Use dev_get_platdata() in staging drivers: tsl2x7x, adcs and frequency
  drivers instead of direct access to the structure element.

1 files changed, 745 insertions, 0 deletions

diff --git a/drivers/iio/adc/ina2xx-adc.c b/drivers/iio/adc/ina2xx-adc.c
new file mode 100644
index 000000000000..4c18c4cc8939
--- /dev/null
+++ b/drivers/iio/adc/ina2xx-adc.c
@@ -0,0 +1,745 @@
+/*
+ * 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/module.h>
+#include <linux/kthread.h>
+#include <linux/delay.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/sysfs.h>
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+#include <linux/platform_data/ina2xx.h>
+
+#include <linux/util_macros.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		0x06
+#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;
+	s64 prev_ns;	/* track buffer capture time, check for underruns*/
+	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 < 0)
+			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*1000/shunt_div */
+			*val2 = chip->config->shunt_div;
+			*val = 1000;
+			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);
+	int ret;
+	unsigned int config, tmp;
+
+	if (iio_buffer_enabled(indio_dev))
+		return -EBUSY;
+
+	mutex_lock(&chip->state_lock);
+
+	ret = regmap_read(chip->regmap, INA2XX_CONFIG, &config);
+	if (ret < 0)
+		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;
+}
+
+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;
+
+	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_LE, \
+	} \
+}
+
+/*
+ * 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_CURRENT, 2, INA2XX_CURRENT),
+	INA2XX_CHAN(IIO_POWER, 3, INA2XX_POWER),
+	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;
+	unsigned long buffer_us, elapsed_us;
+	s64 time_a, time_b;
+	unsigned int alert;
+
+	time_a = iio_get_time_ns();
+
+	/*
+	 * 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;
+			trace_printk("Conversion ready: %d\n", !!alert);
+
+		} 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();
+
+	iio_push_to_buffers_with_timestamp(indio_dev,
+					   (unsigned int *)data, time_a);
+
+	buffer_us = (unsigned long)(time_b - time_a) / 1000;
+	elapsed_us = (unsigned long)(time_a - chip->prev_ns) / 1000;
+
+	trace_printk("uS: elapsed: %lu, buf: %lu\n", elapsed_us, buffer_us);
+
+	chip->prev_ns = time_a;
+
+	return buffer_us;
+};
+
+static int ina2xx_capture_thread(void *data)
+{
+	struct iio_dev *indio_dev = (struct iio_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);
+
+	trace_printk("Enabling buffer w/ scan_mask %02x, freq = %d, avg =%u\n",
+		     (unsigned int)(*indio_dev->active_scan_mask),
+		     1000000/sampling_us, chip->avg);
+
+	trace_printk("Expected work period: %u us\n", sampling_us);
+	trace_printk("Async readout mode: %d\n", chip->allow_async_readout);
+
+	chip->prev_ns = iio_get_time_ns();
+
+	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 = {
+	.debugfs_reg_access = &ina2xx_debug_reg,
+	.read_raw = &ina2xx_read_raw,
+	.write_raw = &ina2xx_write_raw,
+	.attrs = &ina2xx_attribute_group,
+	.driver_module = THIS_MODULE,
+};
+
+/* Initialize the configuration and calibration registers. */
+static int ina2xx_init(struct ina2xx_chip_info *chip, unsigned int config)
+{
+	u16 regval;
+	int ret = regmap_write(chip->regmap, INA2XX_CONFIG, config);
+
+	if (ret < 0)
+		return ret;
+	/*
+	 * 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.
+	 */
+	regval = DIV_ROUND_CLOSEST(chip->config->calibration_factor,
+			    chip->shunt_resistor);
+
+	return regmap_write(chip->regmap, INA2XX_CALIBRATION, regval);
+}
+
+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;
+	int ret;
+	unsigned int val;
+
+	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*chip));
+	if (!indio_dev)
+		return -ENOMEM;
+
+	chip = iio_priv(indio_dev);
+
+	chip->config = &ina2xx_config[id->driver_data];
+
+	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;
+
+	mutex_init(&chip->state_lock);
+
+	/* This is only used for device removal purposes. */
+	i2c_set_clientdata(client, indio_dev);
+
+	indio_dev->name = id->name;
+	indio_dev->channels = ina2xx_channels;
+	indio_dev->num_channels = ARRAY_SIZE(ina2xx_channels);
+
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->info = &ina2xx_info;
+	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
+
+	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);
+	}
+
+	/* 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 < 0) {
+		dev_err(&client->dev, "error configuring the device: %d\n",
+			ret);
+		return -ENODEV;
+	}
+
+	buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
+	if (!buffer)
+		return -ENOMEM;
+
+	indio_dev->setup_ops = &ina2xx_setup_ops;
+
+	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 struct i2c_driver ina2xx_driver = {
+	.driver = {
+		   .name = KBUILD_MODNAME,
+	},
+	.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");