Merge tag 'iio-for-4.8a' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

First round of IIO new device support, features and cleanups for the 4.8 cycle.

New device support
* ads1015
  - add ads1115 support
* bma220 accelerometer
  - new driver
  - triggered buffer support.
* bmc150
  - add bmm150 support.
* bmp280
  - bme280 support with addition of humidity channel.
* max5487 potentiometer
  - new driver
* MMA7660FC accelerometer.
  - New driver
* st-pressure
  - support for the lps22hb
* loop trigger.
  - This one is *nasty* but we have real applications (parrot drones) where
  it is useful.  The trigger basically spins as hard as it can firing off
  a new trigger each time all triggered devices come back to say they are
  done.  It doesn't hang a machine even when doing it on a dummy driver.
  A lot nicer than having this implemented within lots of device drivers
  anyway.

Core stuff
* Add support to create IIO devices via configfs (similar to we did for
triggers a while back) + docs.
* New channel types
  - IIO_ELECTRICAL_CONDUCTIVITY
* Couple of MAINTAINERS patches to list the device tree bindings.
* Make trigger ops structure non optional (comment fix). It hasn't been for
an awful long time, but that's not what the description said.

New features
* ak8975
  - support adapters that are limited to byte data only by allowing the
  emulated block read i2c function that was recently introduced.
* atlas-ph
  - support atlas-ec (electrical conductivity sensor)
* bmi160
  - add available frequency and scale attributes to make the driver
  more user friendly (and avoid having to read the datasheet to know
  what will work).
* dummy
  - move creation to configfs interface.  It's not real hardware so we
  are not that worried about the ABI breakage ;)
* mma8452
  - oversampling ration support
* nau7802
  - expose available gains to make life easier for userspace.
* st-sensors
  - allow use of emulation for SMBus block reads as all the st parts support
  it.
* ti-ads1015
  - list datasheet names to allow their use by inkernel consumers.
* Various module alias additions to help auto probing.  Drop one redundant one
as well.

Cleanups
* ad7266, ad7476, ad7887, ad7923, ad799x
  - use direct mode claim function rather than open coding it during sensor
  read (prevents switching on buffers mid read).
* ad7793, ad7791
  - use direct mode claim to prevent frequency changes when buffers running.
* afe440x - These are ABI breaking but the driver requires custom userspace
  code to do anything useful anyway and that is still being written and under
  control of TI.  Ultimately we may have other libraries to do pulse
  oximetry with these devices but we aren't aware of any yet.
  - kernel-doc format fixes
  - drop ifdef fun around of_match_ptr - it's not worth the mess to save
  a tiny amount of space.
  - drop some unnecessary register initializations.
  - drop the weird locked gain modes as they gain us nothing (can just set
  all gains separately).
  - remove handling of offset attributes seeing as no channels actually have
  them (oops)
  - Drop the LED3 input channel as it's an alias for ALED2.
  - *big one* remove channel names - an experiment that turned out to not
  make sense - see patch for details.
  - use regmap fields to clean up code.
  - tie the tia gain stages to appropriate channels in the ABI as that is
  what they really effect. Same with the LED currents.
  - cleanout some unused defines and fix a missnamed one.
* atlas-ph
  - reorganise to allow support of other similar parts.
* bmc150
  - document supported chips in kconfig help.
* jsa1212
  - drop an unneeded i2c functionality check for functionality the driver
  doesn't use.
* mxs-lradc
  - simply touch screen registration code.
  - remove the touch screen unregister as all devm based now.
  - disable only those channels that are masked in hardware stop (others
  are already dealt with elsewhere)
* st-sensors
  - unexport st_sensors_get_buffer_element as nothing outside the st-sensors
  core driver uses it.
  - fix handling of failure to start up regulators.
* tpl0102
  - drop an i2c functionality test for features that aren't needed.
* ti-am335x
  - use variable name rather than type in sizeof for clarity.
  - use SIMPLE_DEV_PM_OPS helper macro to tidy up a bit.

Tools
* Add install / uninstall to makefile.  Someone cares, so presumably
some people will find it useful!
*  generic_buffer
   - rename to iio_generic_buffer to line up with other tools.
   - handle cleanup when receiving signals
   - Add a --device-num option and a --trigger-num option rather than
   relying on naming which doesn't work if you have two of the same part.

59 files changed, 2439 insertions, 742 deletions

diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index 505e921f0b19..6743b18194fb 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -46,6 +46,14 @@ config IIO_CONSUMERS_PER_TRIGGER
 	This value controls the maximum number of consumers that a
 	given trigger may handle. Default is 2.
 
+config IIO_SW_DEVICE
+	tristate "Enable software IIO device support"
+	select IIO_CONFIGFS
+	help
+	 Provides IIO core support for software devices. A software
+	 device can be created via configfs or directly by a driver
+	 using the API provided.
+
 config IIO_SW_TRIGGER
 	tristate "Enable software triggers support"
 	select IIO_CONFIGFS
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 20f649073462..87e4c4369e2f 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -8,6 +8,7 @@ industrialio-$(CONFIG_IIO_BUFFER) += industrialio-buffer.o
 industrialio-$(CONFIG_IIO_TRIGGER) += industrialio-trigger.o
 
 obj-$(CONFIG_IIO_CONFIGFS) += industrialio-configfs.o
+obj-$(CONFIG_IIO_SW_DEVICE) += industrialio-sw-device.o
 obj-$(CONFIG_IIO_SW_TRIGGER) += industrialio-sw-trigger.o
 obj-$(CONFIG_IIO_TRIGGERED_EVENT) += industrialio-triggered-event.o
 
diff --git a/drivers/iio/accel/Kconfig b/drivers/iio/accel/Kconfig
index e4a758cd7d35..31325870a9ef 100644
--- a/drivers/iio/accel/Kconfig
+++ b/drivers/iio/accel/Kconfig
@@ -17,6 +17,16 @@ config BMA180
 	  To compile this driver as a module, choose M here: the
 	  module will be called bma180.
 
+config BMA220
+    tristate "Bosch BMA220 3-Axis Accelerometer Driver"
+	depends on SPI
+    help
+      Say yes here to add support for the Bosch BMA220 triaxial
+      acceleration sensor.
+
+      To compile this driver as a module, choose M here: the
+      module will be called bma220_spi.
+
 config BMC150_ACCEL
 	tristate "Bosch BMC150 Accelerometer Driver"
 	select IIO_BUFFER
@@ -136,6 +146,16 @@ config MMA7455_SPI
 	  To compile this driver as a module, choose M here: the module
 	  will be called mma7455_spi.
 
+config MMA7660
+	tristate "Freescale MMA7660FC 3-Axis Accelerometer Driver"
+	depends on I2C
+	help
+	  Say yes here to get support for the Freescale MMA7660FC 3-Axis
+	  accelerometer.
+
+	  Choosing M will build the driver as a module. If so, the module
+	  will be called mma7660.
+
 config MMA8452
 	tristate "Freescale MMA8452Q and similar Accelerometers Driver"
 	depends on I2C
diff --git a/drivers/iio/accel/Makefile b/drivers/iio/accel/Makefile
index 71b6794de885..6cedbecca2ee 100644
--- a/drivers/iio/accel/Makefile
+++ b/drivers/iio/accel/Makefile
@@ -4,6 +4,7 @@
 
 # When adding new entries keep the list in alphabetical order
 obj-$(CONFIG_BMA180) += bma180.o
+obj-$(CONFIG_BMA220) += bma220_spi.o
 obj-$(CONFIG_BMC150_ACCEL) += bmc150-accel-core.o
 obj-$(CONFIG_BMC150_ACCEL_I2C) += bmc150-accel-i2c.o
 obj-$(CONFIG_BMC150_ACCEL_SPI) += bmc150-accel-spi.o
@@ -15,6 +16,8 @@ obj-$(CONFIG_MMA7455)		+= mma7455_core.o
 obj-$(CONFIG_MMA7455_I2C)	+= mma7455_i2c.o
 obj-$(CONFIG_MMA7455_SPI)	+= mma7455_spi.o
 
+obj-$(CONFIG_MMA7660)	+= mma7660.o
+
 obj-$(CONFIG_MMA8452)	+= mma8452.o
 
 obj-$(CONFIG_MMA9551_CORE)	+= mma9551_core.o
diff --git a/drivers/iio/accel/bma220_spi.c b/drivers/iio/accel/bma220_spi.c
new file mode 100644
index 000000000000..1098d10df8e8
--- /dev/null
+++ b/drivers/iio/accel/bma220_spi.c
@@ -0,0 +1,338 @@
+/**
+ * BMA220 Digital triaxial acceleration sensor driver
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ */
+
+#include <linux/acpi.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/iio/triggered_buffer.h>
+
+#define BMA220_REG_ID				0x00
+#define BMA220_REG_ACCEL_X			0x02
+#define BMA220_REG_ACCEL_Y			0x03
+#define BMA220_REG_ACCEL_Z			0x04
+#define BMA220_REG_RANGE			0x11
+#define BMA220_REG_SUSPEND			0x18
+
+#define BMA220_CHIP_ID				0xDD
+#define BMA220_READ_MASK			0x80
+#define BMA220_RANGE_MASK			0x03
+#define BMA220_DATA_SHIFT			2
+#define BMA220_SUSPEND_SLEEP			0xFF
+#define BMA220_SUSPEND_WAKE			0x00
+
+#define BMA220_DEVICE_NAME			"bma220"
+#define BMA220_SCALE_AVAILABLE			"0.623 1.248 2.491 4.983"
+
+#define BMA220_ACCEL_CHANNEL(index, reg, axis) {			\
+	.type = IIO_ACCEL,						\
+	.address = reg,							\
+	.modified = 1,							\
+	.channel2 = IIO_MOD_##axis,					\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),			\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),		\
+	.scan_index = index,						\
+	.scan_type = {							\
+		.sign = 's',						\
+		.realbits = 6,						\
+		.storagebits = 8,					\
+		.shift = BMA220_DATA_SHIFT,				\
+		.endianness = IIO_CPU,					\
+	},								\
+}
+
+enum bma220_axis {
+	AXIS_X,
+	AXIS_Y,
+	AXIS_Z,
+};
+
+static IIO_CONST_ATTR(in_accel_scale_available, BMA220_SCALE_AVAILABLE);
+
+static struct attribute *bma220_attributes[] = {
+	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group bma220_attribute_group = {
+	.attrs = bma220_attributes,
+};
+
+static const int bma220_scale_table[][4] = {
+	{0, 623000}, {1, 248000}, {2, 491000}, {4, 983000}
+};
+
+struct bma220_data {
+	struct spi_device *spi_device;
+	struct mutex lock;
+	s8 buffer[16]; /* 3x8-bit channels + 5x8 padding + 8x8 timestamp */
+	u8 tx_buf[2] ____cacheline_aligned;
+};
+
+static const struct iio_chan_spec bma220_channels[] = {
+	BMA220_ACCEL_CHANNEL(0, BMA220_REG_ACCEL_X, X),
+	BMA220_ACCEL_CHANNEL(1, BMA220_REG_ACCEL_Y, Y),
+	BMA220_ACCEL_CHANNEL(2, BMA220_REG_ACCEL_Z, Z),
+	IIO_CHAN_SOFT_TIMESTAMP(3),
+};
+
+static inline int bma220_read_reg(struct spi_device *spi, u8 reg)
+{
+	return spi_w8r8(spi, reg | BMA220_READ_MASK);
+}
+
+static const unsigned long bma220_accel_scan_masks[] = {
+	BIT(AXIS_X) | BIT(AXIS_Y) | BIT(AXIS_Z),
+	0
+};
+
+static irqreturn_t bma220_trigger_handler(int irq, void *p)
+{
+	int ret;
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct bma220_data *data = iio_priv(indio_dev);
+	struct spi_device *spi = data->spi_device;
+
+	mutex_lock(&data->lock);
+	data->tx_buf[0] = BMA220_REG_ACCEL_X | BMA220_READ_MASK;
+	ret = spi_write_then_read(spi, data->tx_buf, 1, data->buffer,
+				  ARRAY_SIZE(bma220_channels) - 1);
+	if (ret < 0)
+		goto err;
+
+	iio_push_to_buffers_with_timestamp(indio_dev, data->buffer,
+					   pf->timestamp);
+err:
+	mutex_unlock(&data->lock);
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
+
+static int bma220_read_raw(struct iio_dev *indio_dev,
+			   struct iio_chan_spec const *chan,
+			   int *val, int *val2, long mask)
+{
+	int ret;
+	u8 range_idx;
+	struct bma220_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+		ret = bma220_read_reg(data->spi_device, chan->address);
+		if (ret < 0)
+			return -EINVAL;
+		*val = sign_extend32(ret >> BMA220_DATA_SHIFT, 5);
+		return IIO_VAL_INT;
+	case IIO_CHAN_INFO_SCALE:
+		ret = bma220_read_reg(data->spi_device, BMA220_REG_RANGE);
+		if (ret < 0)
+			return ret;
+		range_idx = ret & BMA220_RANGE_MASK;
+		*val = bma220_scale_table[range_idx][0];
+		*val2 = bma220_scale_table[range_idx][1];
+		return IIO_VAL_INT_PLUS_MICRO;
+	}
+
+	return -EINVAL;
+}
+
+static int bma220_write_raw(struct iio_dev *indio_dev,
+			    struct iio_chan_spec const *chan,
+			    int val, int val2, long mask)
+{
+	int i;
+	int ret;
+	int index = -1;
+	struct bma220_data *data = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		for (i = 0; i < ARRAY_SIZE(bma220_scale_table); i++)
+			if (val == bma220_scale_table[i][0] &&
+			    val2 == bma220_scale_table[i][1]) {
+				index = i;
+				break;
+			}
+		if (index < 0)
+			return -EINVAL;
+
+		mutex_lock(&data->lock);
+		data->tx_buf[0] = BMA220_REG_RANGE;
+		data->tx_buf[1] = index;
+		ret = spi_write(data->spi_device, data->tx_buf,
+				sizeof(data->tx_buf));
+		if (ret < 0)
+			dev_err(&data->spi_device->dev,
+				"failed to set measurement range\n");
+		mutex_unlock(&data->lock);
+
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static const struct iio_info bma220_info = {
+	.driver_module		= THIS_MODULE,
+	.read_raw		= bma220_read_raw,
+	.write_raw		= bma220_write_raw,
+	.attrs			= &bma220_attribute_group,
+};
+
+static int bma220_init(struct spi_device *spi)
+{
+	int ret;
+
+	ret = bma220_read_reg(spi, BMA220_REG_ID);
+	if (ret != BMA220_CHIP_ID)
+		return -ENODEV;
+
+	/* Make sure the chip is powered on */
+	ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
+	if (ret < 0)
+		return ret;
+	else if (ret == BMA220_SUSPEND_WAKE)
+		return bma220_read_reg(spi, BMA220_REG_SUSPEND);
+
+	return 0;
+}
+
+static int bma220_deinit(struct spi_device *spi)
+{
+	int ret;
+
+	/* Make sure the chip is powered off */
+	ret = bma220_read_reg(spi, BMA220_REG_SUSPEND);
+	if (ret < 0)
+		return ret;
+	else if (ret == BMA220_SUSPEND_SLEEP)
+		return bma220_read_reg(spi, BMA220_REG_SUSPEND);
+
+	return 0;
+}
+
+static int bma220_probe(struct spi_device *spi)
+{
+	int ret;
+	struct iio_dev *indio_dev;
+	struct bma220_data *data;
+
+	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*data));
+	if (!indio_dev) {
+		dev_err(&spi->dev, "iio allocation failed!\n");
+		return -ENOMEM;
+	}
+
+	data = iio_priv(indio_dev);
+	data->spi_device = spi;
+	spi_set_drvdata(spi, indio_dev);
+	mutex_init(&data->lock);
+
+	indio_dev->dev.parent = &spi->dev;
+	indio_dev->info = &bma220_info;
+	indio_dev->name = BMA220_DEVICE_NAME;
+	indio_dev->modes = INDIO_DIRECT_MODE;
+	indio_dev->channels = bma220_channels;
+	indio_dev->num_channels = ARRAY_SIZE(bma220_channels);
+	indio_dev->available_scan_masks = bma220_accel_scan_masks;
+
+	ret = bma220_init(data->spi_device);
+	if (ret < 0)
+		return ret;
+
+	ret = iio_triggered_buffer_setup(indio_dev, NULL,
+					 bma220_trigger_handler, NULL);
+	if (ret < 0) {
+		dev_err(&spi->dev, "iio triggered buffer setup failed\n");
+		goto err_suspend;
+	}
+
+	ret = iio_device_register(indio_dev);
+	if (ret < 0) {
+		dev_err(&spi->dev, "iio_device_register failed\n");
+		iio_triggered_buffer_cleanup(indio_dev);
+		goto err_suspend;
+	}
+
+	return 0;
+
+err_suspend:
+	return bma220_deinit(spi);
+}
+
+static int bma220_remove(struct spi_device *spi)
+{
+	struct iio_dev *indio_dev = spi_get_drvdata(spi);
+
+	iio_device_unregister(indio_dev);
+	iio_triggered_buffer_cleanup(indio_dev);
+
+	return bma220_deinit(spi);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int bma220_suspend(struct device *dev)
+{
+	struct bma220_data *data =
+			iio_priv(spi_get_drvdata(to_spi_device(dev)));
+
+	/* The chip can be suspended/woken up by a simple register read. */
+	return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND);
+}
+
+static int bma220_resume(struct device *dev)
+{
+	struct bma220_data *data =
+			iio_priv(spi_get_drvdata(to_spi_device(dev)));
+
+	return bma220_read_reg(data->spi_device, BMA220_REG_SUSPEND);
+}
+
+static SIMPLE_DEV_PM_OPS(bma220_pm_ops, bma220_suspend, bma220_resume);
+
+#define BMA220_PM_OPS (&bma220_pm_ops)
+#else
+#define BMA220_PM_OPS NULL
+#endif
+
+static const struct spi_device_id bma220_spi_id[] = {
+	{"bma220", 0},
+	{}
+};
+
+static const struct acpi_device_id bma220_acpi_id[] = {
+	{"BMA0220", 0},
+	{}
+};
+
+MODULE_DEVICE_TABLE(spi, bma220_spi_id);
+
+static struct spi_driver bma220_driver = {
+	.driver = {
+		.name = "bma220_spi",
+		.pm = BMA220_PM_OPS,
+		.acpi_match_table = ACPI_PTR(bma220_acpi_id),
+	},
+	.probe =            bma220_probe,
+	.remove =           bma220_remove,
+	.id_table =         bma220_spi_id,
+};
+
+module_spi_driver(bma220_driver);
+
+MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
+MODULE_DESCRIPTION("BMA220 acceleration sensor driver");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/accel/mma7660.c b/drivers/iio/accel/mma7660.c
new file mode 100644
index 000000000000..0acdee516973
--- /dev/null
+++ b/drivers/iio/accel/mma7660.c
@@ -0,0 +1,277 @@
+/**
+ * Freescale MMA7660FC 3-Axis Accelerometer
+ *
+ * Copyright (c) 2016, Intel Corporation.
+ *
+ * This file is subject to the terms and conditions of version 2 of
+ * the GNU General Public License. See the file COPYING in the main
+ * directory of this archive for more details.
+ *
+ * IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c.
+ */
+
+#include <linux/acpi.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define MMA7660_DRIVER_NAME	"mma7660"
+
+#define MMA7660_REG_XOUT	0x00
+#define MMA7660_REG_YOUT	0x01
+#define MMA7660_REG_ZOUT	0x02
+#define MMA7660_REG_OUT_BIT_ALERT	BIT(6)
+
+#define MMA7660_REG_MODE	0x07
+#define MMA7660_REG_MODE_BIT_MODE	BIT(0)
+#define MMA7660_REG_MODE_BIT_TON	BIT(2)
+
+#define MMA7660_I2C_READ_RETRIES	5
+
+/*
+ * The accelerometer has one measurement range:
+ *
+ * -1.5g - +1.5g (6-bit, signed)
+ *
+ * scale = (1.5 + 1.5) * 9.81 / (2^6 - 1)	= 0.467142857
+ */
+
+#define MMA7660_SCALE_AVAIL	"0.467142857"
+
+const int mma7660_nscale = 467142857;
+
+#define MMA7660_CHANNEL(reg, axis) {	\
+	.type = IIO_ACCEL,	\
+	.address = reg,	\
+	.modified = 1,	\
+	.channel2 = IIO_MOD_##axis,	\
+	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),	\
+	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
+}
+
+static const struct iio_chan_spec mma7660_channels[] = {
+	MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
+	MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
+	MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
+};
+
+enum mma7660_mode {
+	MMA7660_MODE_STANDBY,
+	MMA7660_MODE_ACTIVE
+};
+
+struct mma7660_data {
+	struct i2c_client *client;
+	struct mutex lock;
+	enum mma7660_mode mode;
+};
+
+static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
+
+static struct attribute *mma7660_attributes[] = {
+	&iio_const_attr_in_accel_scale_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group mma7660_attribute_group = {
+	.attrs = mma7660_attributes
+};
+
+static int mma7660_set_mode(struct mma7660_data *data,
+				enum mma7660_mode mode)
+{
+	int ret;
+	struct i2c_client *client = data->client;
+
+	if (mode == data->mode)
+		return 0;
+
+	ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to read sensor mode\n");
+		return ret;
+	}
+
+	if (mode == MMA7660_MODE_ACTIVE) {
+		ret &= ~MMA7660_REG_MODE_BIT_TON;
+		ret |= MMA7660_REG_MODE_BIT_MODE;
+	} else {
+		ret &= ~MMA7660_REG_MODE_BIT_TON;
+		ret &= ~MMA7660_REG_MODE_BIT_MODE;
+	}
+
+	ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
+	if (ret < 0) {
+		dev_err(&client->dev, "failed to change sensor mode\n");
+		return ret;
+	}
+
+	data->mode = mode;
+
+	return ret;
+}
+
+static int mma7660_read_accel(struct mma7660_data *data, u8 address)
+{
+	int ret, retries = MMA7660_I2C_READ_RETRIES;
+	struct i2c_client *client = data->client;
+
+	/*
+	 * Read data. If the Alert bit is set, the register was read at
+	 * the same time as the device was attempting to update the content.
+	 * The solution is to read the register again. Do this only
+	 * MMA7660_I2C_READ_RETRIES times to avoid spending too much time
+	 * in the kernel.
+	 */
+	do {
+		ret = i2c_smbus_read_byte_data(client, address);
+		if (ret < 0) {
+			dev_err(&client->dev, "register read failed\n");
+			return ret;
+		}
+	} while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);
+
+	if (ret & MMA7660_REG_OUT_BIT_ALERT) {
+		dev_err(&client->dev, "all register read retries failed\n");
+		return -ETIMEDOUT;
+	}
+
+	return ret;
+}
+
+static int mma7660_read_raw(struct iio_dev *indio_dev,
+				struct iio_chan_spec const *chan,
+				int *val, int *val2, long mask)
+{
+	struct mma7660_da