Merge tag 'iio-for-3.9d' of git://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio into staging-next

Jonathan writes:

"4th set of IIO new drivers cleanups and fixes for the 3.9 cycle
+ a new spi helper function.

1) Introduce spi_sync_transfer and use it within IIO.  Originally
   it was envisioned that this nice little boilerplate replacement
   would go through the spi tree, but Grant Likely stated he'd
   prefer we take it through IIO as the example usecases were all
   in IIO (and are also in this pull request).  Note that given
   their may have been some unresolved elements related to the
   coccinelle element of the patch, that has been stripped out
   and will doubtlessly follow at a later date (along with
   lots of other patches for drivers elsewhere in the tree).

2) New Invensense MPU6050 driver.  This is stripped down to pretty
   much the basics from the original submission with the intent
   to build up all the fancy bits in an incremental (and hence
   reviewable fashion). It's been through a good few revisions
   so nice to finally merge this.

3) Change to iio_channel_get api to simplify device tree based
   mappings.  The actual mappings are currently under review.

4) Build fixes for !CONFIG_IIO_TRIGGER in the st_sensors driver.
   This one snuck past during review and testing but got picked
   up by Randy Dunlap in a randconfig build.

5) Some max1363 cleanups and enhancements.

6) Some comment fixes to make them coherent and comprehensible.

7) Trivial build warning fix in mxs-lradc"

8 files changed, 1415 insertions, 0 deletions

diff --git a/drivers/iio/imu/Kconfig b/drivers/iio/imu/Kconfig
index 47f66ed..4f40a10 100644
--- a/drivers/iio/imu/Kconfig
+++ b/drivers/iio/imu/Kconfig
@@ -36,3 +36,5 @@ config IIO_ADIS_LIB_BUFFER
 	help
 	  A set of buffer helper functions for the Analog Devices ADIS* device
 	  family.
+
+source "drivers/iio/imu/inv_mpu6050/Kconfig"
diff --git a/drivers/iio/imu/Makefile b/drivers/iio/imu/Makefile
index 019b717..f2f56ce 100644
--- a/drivers/iio/imu/Makefile
+++ b/drivers/iio/imu/Makefile
@@ -11,3 +11,5 @@ adis_lib-y += adis.o
 adis_lib-$(CONFIG_IIO_ADIS_LIB_BUFFER) += adis_trigger.o
 adis_lib-$(CONFIG_IIO_ADIS_LIB_BUFFER) += adis_buffer.o
 obj-$(CONFIG_IIO_ADIS_LIB) += adis_lib.o
+
+obj-y += inv_mpu6050/
diff --git a/drivers/iio/imu/inv_mpu6050/Kconfig b/drivers/iio/imu/inv_mpu6050/Kconfig
new file mode 100644
index 0000000..b5cfa3a
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/Kconfig
@@ -0,0 +1,13 @@
+#
+# inv-mpu6050 drivers for Invensense MPU devices and combos
+#
+
+config INV_MPU6050_IIO
+	tristate "Invensense MPU6050 devices"
+	depends on I2C && SYSFS
+	select IIO_TRIGGERED_BUFFER
+	help
+	  This driver supports the Invensense MPU6050 devices.
+	  It is a gyroscope/accelerometer combo device.
+	  This driver can be built as a module. The module will be called
+	  inv-mpu6050.
diff --git a/drivers/iio/imu/inv_mpu6050/Makefile b/drivers/iio/imu/inv_mpu6050/Makefile
new file mode 100644
index 0000000..3a677c7
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/Makefile
@@ -0,0 +1,6 @@
+#
+# Makefile for Invensense MPU6050 device.
+#
+
+obj-$(CONFIG_INV_MPU6050_IIO) += inv-mpu6050.o
+inv-mpu6050-objs := inv_mpu_core.o inv_mpu_ring.o inv_mpu_trigger.o
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
new file mode 100644
index 0000000..37ca05b
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_core.c
@@ -0,0 +1,795 @@
+/*
+* Copyright (C) 2012 Invensense, Inc.
+*
+* This software is licensed under the terms of the GNU General Public
+* License version 2, as published by the Free Software Foundation, and
+* may be copied, distributed, and modified under those terms.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/spinlock.h>
+#include "inv_mpu_iio.h"
+
+/*
+ * this is the gyro scale translated from dynamic range plus/minus
+ * {250, 500, 1000, 2000} to rad/s
+ */
+static const int gyro_scale_6050[] = {133090, 266181, 532362, 1064724};
+
+/*
+ * this is the accel scale translated from dynamic range plus/minus
+ * {2, 4, 8, 16} to m/s^2
+ */
+static const int accel_scale[] = {598, 1196, 2392, 4785};
+
+static const struct inv_mpu6050_reg_map reg_set_6050 = {
+	.sample_rate_div	= INV_MPU6050_REG_SAMPLE_RATE_DIV,
+	.lpf                    = INV_MPU6050_REG_CONFIG,
+	.user_ctrl              = INV_MPU6050_REG_USER_CTRL,
+	.fifo_en                = INV_MPU6050_REG_FIFO_EN,
+	.gyro_config            = INV_MPU6050_REG_GYRO_CONFIG,
+	.accl_config            = INV_MPU6050_REG_ACCEL_CONFIG,
+	.fifo_count_h           = INV_MPU6050_REG_FIFO_COUNT_H,
+	.fifo_r_w               = INV_MPU6050_REG_FIFO_R_W,
+	.raw_gyro               = INV_MPU6050_REG_RAW_GYRO,
+	.raw_accl               = INV_MPU6050_REG_RAW_ACCEL,
+	.temperature            = INV_MPU6050_REG_TEMPERATURE,
+	.int_enable             = INV_MPU6050_REG_INT_ENABLE,
+	.pwr_mgmt_1             = INV_MPU6050_REG_PWR_MGMT_1,
+	.pwr_mgmt_2             = INV_MPU6050_REG_PWR_MGMT_2,
+};
+
+static const struct inv_mpu6050_chip_config chip_config_6050 = {
+	.fsr = INV_MPU6050_FSR_2000DPS,
+	.lpf = INV_MPU6050_FILTER_20HZ,
+	.fifo_rate = INV_MPU6050_INIT_FIFO_RATE,
+	.gyro_fifo_enable = false,
+	.accl_fifo_enable = false,
+	.accl_fs = INV_MPU6050_FS_02G,
+};
+
+static const struct inv_mpu6050_hw hw_info[INV_NUM_PARTS] = {
+	{
+		.num_reg = 117,
+		.name = "MPU6050",
+		.reg = &reg_set_6050,
+		.config = &chip_config_6050,
+	},
+};
+
+int inv_mpu6050_write_reg(struct inv_mpu6050_state *st, int reg, u8 d)
+{
+	return i2c_smbus_write_i2c_block_data(st->client, reg, 1, &d);
+}
+
+int inv_mpu6050_switch_engine(struct inv_mpu6050_state *st, bool en, u32 mask)
+{
+	u8 d, mgmt_1;
+	int result;
+
+	/* switch clock needs to be careful. Only when gyro is on, can
+	   clock source be switched to gyro. Otherwise, it must be set to
+	   internal clock */
+	if (INV_MPU6050_BIT_PWR_GYRO_STBY == mask) {
+		result = i2c_smbus_read_i2c_block_data(st->client,
+				       st->reg->pwr_mgmt_1, 1, &mgmt_1);
+		if (result != 1)
+			return result;
+
+		mgmt_1 &= ~INV_MPU6050_BIT_CLK_MASK;
+	}
+
+	if ((INV_MPU6050_BIT_PWR_GYRO_STBY == mask) && (!en)) {
+		/* turning off gyro requires switch to internal clock first.
+		   Then turn off gyro engine */
+		mgmt_1 |= INV_CLK_INTERNAL;
+		result = inv_mpu6050_write_reg(st, st->reg->pwr_mgmt_1, mgmt_1);
+		if (result)
+			return result;
+	}
+
+	result = i2c_smbus_read_i2c_block_data(st->client,
+				       st->reg->pwr_mgmt_2, 1, &d);
+	if (result != 1)
+		return result;
+	if (en)
+		d &= ~mask;
+	else
+		d |= mask;
+	result = inv_mpu6050_write_reg(st, st->reg->pwr_mgmt_2, d);
+	if (result)
+		return result;
+
+	if (en) {
+		/* Wait for output stablize */
+		msleep(INV_MPU6050_TEMP_UP_TIME);
+		if (INV_MPU6050_BIT_PWR_GYRO_STBY == mask) {
+			/* switch internal clock to PLL */
+			mgmt_1 |= INV_CLK_PLL;
+			result = inv_mpu6050_write_reg(st,
+					st->reg->pwr_mgmt_1, mgmt_1);
+			if (result)
+				return result;
+		}
+	}
+
+	return 0;
+}
+
+int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on)
+{
+	int result;
+
+	if (power_on)
+		result = inv_mpu6050_write_reg(st, st->reg->pwr_mgmt_1, 0);
+	else
+		result = inv_mpu6050_write_reg(st, st->reg->pwr_mgmt_1,
+						INV_MPU6050_BIT_SLEEP);
+	if (result)
+		return result;
+
+	if (power_on)
+		msleep(INV_MPU6050_REG_UP_TIME);
+
+	return 0;
+}
+
+/**
+ *  inv_mpu6050_init_config() - Initialize hardware, disable FIFO.
+ *
+ *  Initial configuration:
+ *  FSR: ± 2000DPS
+ *  DLPF: 20Hz
+ *  FIFO rate: 50Hz
+ *  Clock source: Gyro PLL
+ */
+static int inv_mpu6050_init_config(struct iio_dev *indio_dev)
+{
+	int result;
+	u8 d;
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+
+	result = inv_mpu6050_set_power_itg(st, true);
+	if (result)
+		return result;
+	d = (INV_MPU6050_FSR_2000DPS << INV_MPU6050_GYRO_CONFIG_FSR_SHIFT);
+	result = inv_mpu6050_write_reg(st, st->reg->gyro_config, d);
+	if (result)
+		return result;
+
+	d = INV_MPU6050_FILTER_20HZ;
+	result = inv_mpu6050_write_reg(st, st->reg->lpf, d);
+	if (result)
+		return result;
+
+	d = INV_MPU6050_ONE_K_HZ / INV_MPU6050_INIT_FIFO_RATE - 1;
+	result = inv_mpu6050_write_reg(st, st->reg->sample_rate_div, d);
+	if (result)
+		return result;
+
+	d = (INV_MPU6050_FS_02G << INV_MPU6050_ACCL_CONFIG_FSR_SHIFT);
+	result = inv_mpu6050_write_reg(st, st->reg->accl_config, d);
+	if (result)
+		return result;
+
+	memcpy(&st->chip_config, hw_info[st->chip_type].config,
+		sizeof(struct inv_mpu6050_chip_config));
+	result = inv_mpu6050_set_power_itg(st, false);
+
+	return result;
+}
+
+static int inv_mpu6050_sensor_show(struct inv_mpu6050_state  *st, int reg,
+				int axis, int *val)
+{
+	int ind, result;
+	__be16 d;
+
+	ind = (axis - IIO_MOD_X) * 2;
+	result = i2c_smbus_read_i2c_block_data(st->client, reg + ind,  2,
+						(u8 *)&d);
+	if (result != 2)
+		return -EINVAL;
+	*val = (short)be16_to_cpup(&d);
+
+	return IIO_VAL_INT;
+}
+
+static int inv_mpu6050_read_raw(struct iio_dev *indio_dev,
+			      struct iio_chan_spec const *chan,
+			      int *val,
+			      int *val2,
+			      long mask) {
+	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
+
+	switch (mask) {
+	case IIO_CHAN_INFO_RAW:
+	{
+		int ret, result;
+
+		ret = IIO_VAL_INT;
+		result = 0;
+		mutex_lock(&indio_dev->mlock);
+		if (!st->chip_config.enable) {
+			result = inv_mpu6050_set_power_itg(st, true);
+			if (result)
+				goto error_read_raw;
+		}
+		/* when enable is on, power is already on */
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			if (!st->chip_config.gyro_fifo_enable ||
+					!st->chip_config.enable) {
+				result = inv_mpu6050_switch_engine(st, true,
+						INV_MPU6050_BIT_PWR_GYRO_STBY);
+				if (result)
+					goto error_read_raw;
+			}
+			ret =  inv_mpu6050_sensor_show(st, st->reg->raw_gyro,
+						chan->channel2, val);
+			if (!st->chip_config.gyro_fifo_enable ||
+					!st->chip_config.enable) {
+				result = inv_mpu6050_switch_engine(st, false,
+						INV_MPU6050_BIT_PWR_GYRO_STBY);
+				if (result)
+					goto error_read_raw;
+			}
+			break;
+		case IIO_ACCEL:
+			if (!st->chip_config.accl_fifo_enable ||
+					!st->chip_config.enable) {
+				result = inv_mpu6050_switch_engine(st, true,
+						INV_MPU6050_BIT_PWR_ACCL_STBY);
+				if (result)
+					goto error_read_raw;
+			}
+			ret = inv_mpu6050_sensor_show(st, st->reg->raw_accl,
+						chan->channel2, val);
+			if (!st->chip_config.accl_fifo_enable ||
+					!st->chip_config.enable) {
+				result = inv_mpu6050_switch_engine(st, false,
+						INV_MPU6050_BIT_PWR_ACCL_STBY);
+				if (result)
+					goto error_read_raw;
+			}
+			break;
+		case IIO_TEMP:
+			/* wait for stablization */
+			msleep(INV_MPU6050_SENSOR_UP_TIME);
+			inv_mpu6050_sensor_show(st, st->reg->temperature,
+							IIO_MOD_X, val);
+			break;
+		default:
+			ret = -EINVAL;
+			break;
+		}
+error_read_raw:
+		if (!st->chip_config.enable)
+			result |= inv_mpu6050_set_power_itg(st, false);
+		mutex_unlock(&indio_dev->mlock);
+		if (result)
+			return result;
+
+		return ret;
+	}
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			*val  = 0;
+			*val2 = gyro_scale_6050[st->chip_config.fsr];
+
+			return IIO_VAL_INT_PLUS_NANO;
+		case IIO_ACCEL:
+			*val = 0;
+			*val2 = accel_scale[st->chip_config.accl_fs];
+
+			return IIO_VAL_INT_PLUS_MICRO;
+		case IIO_TEMP:
+			*val = 0;
+			*val2 = INV_MPU6050_TEMP_SCALE;
+
+			return IIO_VAL_INT_PLUS_MICRO;
+		default:
+			return -EINVAL;
+		}
+	case IIO_CHAN_INFO_OFFSET:
+		switch (chan->type) {
+		case IIO_TEMP:
+			*val = INV_MPU6050_TEMP_OFFSET;
+
+			return IIO_VAL_INT;
+		default:
+			return -EINVAL;
+		}
+	default:
+		return -EINVAL;
+	}
+}
+
+static int inv_mpu6050_write_fsr(struct inv_mpu6050_state *st, int fsr)
+{
+	int result;
+	u8 d;
+
+	if (fsr < 0 || fsr > INV_MPU6050_MAX_GYRO_FS_PARAM)
+		return -EINVAL;
+	if (fsr == st->chip_config.fsr)
+		return 0;
+
+	d = (fsr << INV_MPU6050_GYRO_CONFIG_FSR_SHIFT);
+	result = inv_mpu6050_write_reg(st, st->reg->gyro_config, d);
+	if (result)
+		return result;
+	st->chip_config.fsr = fsr;
+
+	return 0;
+}
+
+static int inv_mpu6050_write_accel_fs(struct inv_mpu6050_state *st, int fs)
+{
+	int result;
+	u8 d;
+
+	if (fs < 0 || fs > INV_MPU6050_MAX_ACCL_FS_PARAM)
+		return -EINVAL;
+	if (fs == st->chip_config.accl_fs)
+		return 0;
+
+	d = (fs << INV_MPU6050_ACCL_CONFIG_FSR_SHIFT);
+	result = inv_mpu6050_write_reg(st, st->reg->accl_config, d);
+	if (result)
+		return result;
+	st->chip_config.accl_fs = fs;
+
+	return 0;
+}
+
+static int inv_mpu6050_write_raw(struct iio_dev *indio_dev,
+			       struct iio_chan_spec const *chan,
+			       int val,
+			       int val2,
+			       long mask) {
+	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
+	int result;
+
+	mutex_lock(&indio_dev->mlock);
+	/* we should only update scale when the chip is disabled, i.e.,
+		not running */
+	if (st->chip_config.enable) {
+		result = -EBUSY;
+		goto error_write_raw;
+	}
+	result = inv_mpu6050_set_power_itg(st, true);
+	if (result)
+		goto error_write_raw;
+
+	switch (mask) {
+	case IIO_CHAN_INFO_SCALE:
+		switch (chan->type) {
+		case IIO_ANGL_VEL:
+			result = inv_mpu6050_write_fsr(st, val);
+			break;
+		case IIO_ACCEL:
+			result = inv_mpu6050_write_accel_fs(st, val);
+			break;
+		default:
+			result = -EINVAL;
+			break;
+		}
+		break;
+	default:
+		result = -EINVAL;
+		break;
+	}
+
+error_write_raw:
+	result |= inv_mpu6050_set_power_itg(st, false);
+	mutex_unlock(&indio_dev->mlock);
+
+	return result;
+}
+
+/**
+ *  inv_mpu6050_set_lpf() - set low pass filer based on fifo rate.
+ *
+ *                  Based on the Nyquist principle, the sampling rate must
+ *                  exceed twice of the bandwidth of the signal, or there
+ *                  would be alising. This function basically search for the
+ *                  correct low pass parameters based on the fifo rate, e.g,
+ *                  sampling frequency.
+ */
+static int inv_mpu6050_set_lpf(struct inv_mpu6050_state *st, int rate)
+{
+	const int hz[] = {188, 98, 42, 20, 10, 5};
+	const int d[] = {INV_MPU6050_FILTER_188HZ, INV_MPU6050_FILTER_98HZ,
+			INV_MPU6050_FILTER_42HZ, INV_MPU6050_FILTER_20HZ,
+			INV_MPU6050_FILTER_10HZ, INV_MPU6050_FILTER_5HZ};
+	int i, h, result;
+	u8 data;
+
+	h = (rate >> 1);
+	i = 0;
+	while ((h < hz[i]) && (i < ARRAY_SIZE(d) - 1))
+		i++;
+	data = d[i];
+	result = inv_mpu6050_write_reg(st, st->reg->lpf, data);
+	if (result)
+		return result;
+	st->chip_config.lpf = data;
+
+	return 0;
+}
+
+/**
+ * inv_mpu6050_fifo_rate_store() - Set fifo rate.
+ */
+static ssize_t inv_mpu6050_fifo_rate_store(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	s32 fifo_rate;
+	u8 d;
+	int result;
+	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+
+	if (kstrtoint(buf, 10, &fifo_rate))
+		return -EINVAL;
+	if (fifo_rate < INV_MPU6050_MIN_FIFO_RATE ||
+				fifo_rate > INV_MPU6050_MAX_FIFO_RATE)
+		return -EINVAL;
+	if (fifo_rate == st->chip_config.fifo_rate)
+		return count;
+
+	mutex_lock(&indio_dev->mlock);
+	if (st->chip_config.enable) {
+		result = -EBUSY;
+		goto fifo_rate_fail;
+	}
+	result = inv_mpu6050_set_power_itg(st, true);
+	if (result)
+		goto fifo_rate_fail;
+
+	d = INV_MPU6050_ONE_K_HZ / fifo_rate - 1;
+	result = inv_mpu6050_write_reg(st, st->reg->sample_rate_div, d);
+	if (result)
+		goto fifo_rate_fail;
+	st->chip_config.fifo_rate = fifo_rate;
+
+	result = inv_mpu6050_set_lpf(st, fifo_rate);
+	if (result)
+		goto fifo_rate_fail;
+
+fifo_rate_fail:
+	result |= inv_mpu6050_set_power_itg(st, false);
+	mutex_unlock(&indio_dev->mlock);
+	if (result)
+		return result;
+
+	return count;
+}
+
+/**
+ * inv_fifo_rate_show() - Get the current sampling rate.
+ */
+static ssize_t inv_fifo_rate_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct inv_mpu6050_state *st = iio_priv(dev_to_iio_dev(dev));
+
+	return sprintf(buf, "%d\n", st->chip_config.fifo_rate);
+}
+
+/**
+ * inv_attr_show() - calling this function will show current
+ *                    parameters.
+ */
+static ssize_t inv_attr_show(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	struct inv_mpu6050_state *st = iio_priv(dev_to_iio_dev(dev));
+	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+	s8 *m;
+
+	switch (this_attr->address) {
+	/* In MPU6050, the two matrix are the same because gyro and accel
+	   are integrated in one chip */
+	case ATTR_GYRO_MATRIX:
+	case ATTR_ACCL_MATRIX:
+		m = st->plat_data.orientation;
+
+		return sprintf(buf, "%d, %d, %d; %d, %d, %d; %d, %d, %d\n",
+			m[0], m[1], m[2], m[3], m[4], m[5], m[6], m[7], m[8]);
+	default:
+		return -EINVAL;
+	}
+}
+
+/**
+ * inv_mpu6050_validate_trigger() - validate_trigger callback for invensense
+ *                                  MPU6050 device.
+ * @indio_dev: The IIO device
+ * @trig: The new trigger
+ *
+ * Returns: 0 if the 'trig' matches the trigger registered by the MPU6050
+ * device, -EINVAL otherwise.
+ */
+static int inv_mpu6050_validate_trigger(struct iio_dev *indio_dev,
+					struct iio_trigger *trig)
+{
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+
+	if (st->trig != trig)
+		return -EINVAL;
+
+	return 0;
+}
+
+#define INV_MPU6050_CHAN(_type, _channel2, _index)                    \
+	{                                                             \
+		.type = _type,                                        \
+		.modified = 1,                                        \
+		.channel2 = _channel2,                                \
+		.info_mask =  IIO_CHAN_INFO_SCALE_SHARED_BIT          \
+				| IIO_CHAN_INFO_RAW_SEPARATE_BIT,     \
+		.scan_index = _index,                                 \
+		.scan_type = {                                        \
+				.sign = 's',                          \
+				.realbits = 16,                       \
+				.storagebits = 16,                    \
+				.shift = 0 ,                          \
+				.endianness = IIO_BE,                 \
+			     },                                       \
+	}
+
+static const struct iio_chan_spec inv_mpu_channels[] = {
+	IIO_CHAN_SOFT_TIMESTAMP(INV_MPU6050_SCAN_TIMESTAMP),
+	/*
+	 * Note that temperature should only be via polled reading only,
+	 * not the final scan elements output.
+	 */
+	{
+		.type = IIO_TEMP,
+		.info_mask =  IIO_CHAN_INFO_RAW_SEPARATE_BIT
+				| IIO_CHAN_INFO_OFFSET_SEPARATE_BIT
+				| IIO_CHAN_INFO_SCALE_SEPARATE_BIT,
+		.scan_index = -1,
+	},
+	INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_X, INV_MPU6050_SCAN_GYRO_X),
+	INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Y, INV_MPU6050_SCAN_GYRO_Y),
+	INV_MPU6050_CHAN(IIO_ANGL_VEL, IIO_MOD_Z, INV_MPU6050_SCAN_GYRO_Z),
+
+	INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_X, INV_MPU6050_SCAN_ACCL_X),
+	INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Y, INV_MPU6050_SCAN_ACCL_Y),
+	INV_MPU6050_CHAN(IIO_ACCEL, IIO_MOD_Z, INV_MPU6050_SCAN_ACCL_Z),
+};
+
+/* constant IIO attribute */
+static IIO_CONST_ATTR_SAMP_FREQ_AVAIL("10 20 50 100 200 500");
+static IIO_DEV_ATTR_SAMP_FREQ(S_IRUGO | S_IWUSR, inv_fifo_rate_show,
+	inv_mpu6050_fifo_rate_store);
+static IIO_DEVICE_ATTR(in_gyro_matrix, S_IRUGO, inv_attr_show, NULL,
+	ATTR_GYRO_MATRIX);
+static IIO_DEVICE_ATTR(in_accel_matrix, S_IRUGO, inv_attr_show, NULL,
+	ATTR_ACCL_MATRIX);
+
+static struct attribute *inv_attributes[] = {
+	&iio_dev_attr_in_gyro_matrix.dev_attr.attr,
+	&iio_dev_attr_in_accel_matrix.dev_attr.attr,
+	&iio_dev_attr_sampling_frequency.dev_attr.attr,
+	&iio_const_attr_sampling_frequency_available.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group inv_attribute_group = {
+	.attrs = inv_attributes
+};
+
+static const struct iio_info mpu_info = {
+	.driver_module = THIS_MODULE,
+	.read_raw = &inv_mpu6050_read_raw,
+	.write_raw = &inv_mpu6050_write_raw,
+	.attrs = &inv_attribute_group,
+	.validate_trigger = inv_mpu6050_validate_trigger,
+};
+
+/**
+ *  inv_check_and_setup_chip() - check and setup chip.
+ */
+static int inv_check_and_setup_chip(struct inv_mpu6050_state *st,
+		const struct i2c_device_id *id)
+{
+	int result;
+
+	st->chip_type = INV_MPU6050;
+	st->hw  = &hw_info[st->chip_type];
+	st->reg = hw_info[st->chip_type].reg;
+
+	/* reset to make sure previous state are not there */
+	result = inv_mpu6050_write_reg(st, st->reg->pwr_mgmt_1,
+					INV_MPU6050_BIT_H_RESET);
+	if (result)
+		return result;
+	msleep(INV_MPU6050_POWER_UP_TIME);
+	/* toggle power state. After reset, the sleep bit could be on
+		or off depending on the OTP settings. Toggling power would
+		make it in a definite state as well as making the hardware
+		state align with the software state */
+	result = inv_mpu6050_set_power_itg(st, false);
+	if (result)
+		return result;
+	result = inv_mpu6050_set_power_itg(st, true);
+	if (result)
+		return result;
+
+	result = inv_mpu6050_switch_engine(st, false,
+					INV_MPU6050_BIT_PWR_ACCL_STBY);
+	if (result)
+		return result;
+	result = inv_mpu6050_switch_engine(st, false,
+					INV_MPU6050_BIT_PWR_GYRO_STBY);
+	if (result)
+		return result;
+
+	return 0;
+}
+
+/**
+ *  inv_mpu_probe() - probe function.
+ *  @client:          i2c client.
+ *  @id:              i2c device id.
+ *
+ *  Returns 0 on success, a negative error code otherwise.
+ */
+static int inv_mpu_probe(struct i2c_client *client,
+	const struct i2c_device_id *id)
+{
+	struct inv_mpu6050_state *st;
+	struct iio_dev *indio_dev;
+	int result;
+
+	if (!i2c_check_functionality(client->adapter,
+					I2C_FUNC_SMBUS_READ_I2C_BLOCK |
+					I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)) {
+		result = -ENOSYS;
+		goto out_no_free;
+	}
+	indio_dev = iio_device_alloc(sizeof(*st));
+	if (indio_dev == NULL) {
+		result =  -ENOMEM;
+		goto out_no_free;
+	}
+	st = iio_priv(indio_dev);
+	st->client = client;
+	st->plat_data = *(struct inv_mpu6050_platform_data
+				*)dev_get_platdata(&client->dev);
+	/* power is turned on inside check chip type*/
+	result = inv_check_and_setup_chip(st, id);
+	if (result)
+		goto out_free;
+
+	result = inv_mpu6050_init_config(indio_dev);
+	if (result) {
+		dev_err(&client->dev,
+			"Could not initialize device.\n");
+		goto out_free;
+	}
+
+	i2c_set_clientdata(client, indio_dev);
+	indio_dev->dev.parent = &client->dev;
+	indio_dev->name = id->name;
+	indio_dev->channels = inv_mpu_channels;
+	indio_dev->num_channels = ARRAY_SIZE(inv_mpu_channels);
+
+	indio_dev->info = &mpu_info;
+	indio_dev->modes = INDIO_BUFFER_TRIGGERED;
+
+	result = iio_triggered_buffer_setup(indio_dev,
+					    inv_mpu6050_irq_handler,
+					    inv_mpu6050_read_fifo,
+					    NULL);
+	if (result) {
+		dev_err(&st->client->dev, "configure buffer fail %d\n",
+				result);
+		goto out_free;
+	}
+	result = inv_mpu6050_probe_trigger(indio_dev);
+	if (result) {
+		dev_err(&st->client->dev, "trigger probe fail %d\n", result);
+		goto out_unreg_ring;
+	}
+
+	INIT_KFIFO(st->timestamps);
+	spin_lock_init(&st->time_stamp_lock);
+	result = iio_device_register(indio_dev);
+	if (result) {
+		dev_err(&st->client->dev, "IIO register fail %d\n", result);
+		goto out_remove_trigger;
+	}
+
+	return 0;
+
+out_remove_trigger:
+	inv_mpu6050_remove_trigger(st);
+out_unreg_ring:
+	iio_triggered_buffer_cleanup(indio_dev);
+out_free:
+	iio_device_free(indio_dev);
+out_no_free:
+
+	return result;
+}
+
+static int inv_mpu_remove(struct i2c_client *client)
+{
+	struct iio_dev *indio_dev = i2c_get_clientdata(client);
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+
+	iio_device_unregister(indio_dev);
+	inv_mpu6050_remove_trigger(st);
+	iio_triggered_buffer_cleanup(indio_dev);
+	iio_device_free(indio_dev);
+
+	return 0;
+}
+#ifdef CONFIG_PM_SLEEP
+
+static int inv_mpu_resume(struct device *dev)
+{
+	return inv_mpu6050_set_power_itg(
+		iio_priv(i2c_get_clientdata(to_i2c_client(dev))), true);
+}
+
+static int inv_mpu_suspend(struct device *dev)
+{
+	return inv_mpu6050_set_power_itg(
+		iio_priv(i2c_get_clientdata(to_i2c_client(dev))), false);
+}
+static SIMPLE_DEV_PM_OPS(inv_mpu_pmops, inv_mpu_suspend, inv_mpu_resume);
+
+#define INV_MPU6050_PMOPS (&inv_mpu_pmops)
+#else
+#define INV_MPU6050_PMOPS NULL
+#endif /* CONFIG_PM_SLEEP */
+
+/*
+ * device id table is used to identify what device can be
+ * supported by this driver
+ */
+static const struct i2c_device_id inv_mpu_id[] = {
+	{"mpu6050", INV_MPU6050},
+	{}
+};
+
+MODULE_DEVICE_TABLE(i2c, inv_mpu_id);
+
+static struct i2c_driver inv_mpu_driver = {
+	.probe		=	inv_mpu_probe,
+	.remove		=	inv_mpu_remove,
+	.id_table	=	inv_mpu_id,
+	.driver = {
+		.owner	=	THIS_MODULE,
+		.name	=	"inv-mpu6050",
+		.pm     =       INV_MPU6050_PMOPS,
+	},
+};
+
+module_i2c_driver(inv_mpu_driver);
+
+MODULE_AUTHOR("Invensense Corporation");
+MODULE_DESCRIPTION("Invensense device MPU6050 driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
new file mode 100644
index 0000000..f383955
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h
@@ -0,0 +1,246 @@
+/*
+* Copyright (C) 2012 Invensense, Inc.
+*
+* This software is licensed under the terms of the GNU General Public
+* License version 2, as published by the Free Software Foundation, and
+* may be copied, distributed, and modified under those terms.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*/
+#include <linux/i2c.h>
+#include <linux/kfifo.h>
+#include <linux/spinlock.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/buffer.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/kfifo_buf.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+#include <linux/platform_data/invensense_mpu6050.h>
+
+/**
+ *  struct inv_mpu6050_reg_map - Notable registers.
+ *  @sample_rate_div:	Divider applied to gyro output rate.
+ *  @lpf:		Configures internal low pass filter.
+ *  @user_ctrl:		Enables/resets the FIFO.
+ *  @fifo_en:		Determines which data will appear in FIFO.
+ *  @gyro_config:	gyro config register.
+ *  @accl_config:	accel config register
+ *  @fifo_count_h:	Upper byte of FIFO count.
+ *  @fifo_r_w:		FIFO register.
+ *  @raw_gyro:		Address of first gyro register.
+ *  @raw_accl:		Address of first accel register.
+ *  @temperature:	temperature register
+ *  @int_enable:	Interrupt enable register.
+ *  @pwr_mgmt_1:	Controls chip's power state and clock source.
+ *  @pwr_mgmt_2:	Controls power state of individual sensors.
+ */
+struct inv_mpu6050_reg_map {
+	u8 sample_rate_div;
+	u8 lpf;
+	u8 user_ctrl;
+	u8 fifo_en;
+	u8 gyro_config;
+	u8 accl_config;
+	u8 fifo_count_h;
+	u8 fifo_r_w;
+	u8 raw_gyro;
+	u8 raw_accl;
+	u8 temperature;
+	u8 int_enable;
+	u8 pwr_mgmt_1;
+	u8 pwr_mgmt_2;
+};
+
+/*device enum */
+enum inv_devices {
+	INV_MPU6050,
+	INV_NUM_PARTS
+};
+
+/**
+ *  struct inv_mpu6050_chip_config - Cached chip configuration data.
+ *  @fsr:		Full scale range.
+ *  @lpf:		Digital low pass filter frequency.
+ *  @accl_fs:		accel full scale range.
+ *  @enable:		master enable state.
+ *  @accl_fifo_enable:	enable accel data output
+ *  @gyro_fifo_enable:	enable gyro data output
+ *  @fifo_rate:		FIFO update rate.
+ */
+struct inv_mpu6050_chip_config {
+	unsigned int fsr:2;
+	unsigned int lpf:3;
+	unsigned int accl_fs:2;
+	unsigned int enable:1;
+	unsigned int accl_fifo_enable:1;
+	unsigned int gyro_fifo_enable:1;
+	u16 fifo_rate;
+};
+
+/**
+ *  struct inv_mpu6050_hw - Other important hardware information.
+ *  @num_reg:	Number of registers on device.
+ *  @name:      name of the chip.
+ *  @reg:   register map of the chip.
+ *  @config:    configuration of the chip.
+ */
+struct inv_mpu6050_hw {
+	u8 num_reg;
+	u8 *name;
+	const struct inv_mpu6050_reg_map *reg;
+	const struct inv_mpu6050_chip_config *config;
+};
+
+/*
+ *  struct inv_mpu6050_state - Driver state variables.
+ *  @TIMESTAMP_FIFO_SIZE: fifo size for timestamp.
+ *  @trig:              IIO trigger.
+ *  @chip_config:	Cached attribute information.
+ *  @reg:		Map of important registers.
+ *  @hw:		Other hardware-specific information.
+ *  @chip_type:		chip type.
+ *  @time_stamp_lock:	spin lock to time stamp.
+ *  @client:		i2c client handle.
+ *  @plat_data:		platform data.
+ *  @timestamps:        kfifo queue to store time stamp.
+ */
+struct inv_mpu6050_state {
+#define TIMESTAMP_FIFO_SIZE 16
+	struct iio_trigger  *trig;
+	struct inv_mpu6050_chip_config chip_config;
+	const struct inv_mpu6050_reg_map *reg;
+	const struct inv_mpu6050_hw *hw;
+	enum   inv_devices chip_type;
+	spinlock_t time_stamp_lock;
+	struct i2c_client *client;
+	struct inv_mpu6050_platform_data plat_data;
+	DECLARE_KFIFO(timestamps, long long, TIMESTAMP_FIFO_SIZE);
+};
+
+/*register and associated bit definition*/
+#define INV_MPU6050_REG_SAMPLE_RATE_DIV     0x19
+#define INV_MPU6050_REG_CONFIG              0x1A
+#define INV_MPU6050_REG_GYRO_CONFIG         0x1B
+#define INV_MPU6050_REG_ACCEL_CONFIG	    0x1C
+
+#define INV_MPU6050_REG_FIFO_EN             0x23
+#define INV_MPU6050_BIT_ACCEL_OUT                   0x08
+#define INV_MPU6050_BITS_GYRO_OUT                   0x70
+
+#define INV_MPU6050_REG_INT_ENABLE          0x38
+#define INV_MPU6050_BIT_DATA_RDY_EN                 0x01
+#define INV_MPU6050_BIT_DMP_INT_EN                  0x02
+
+#define INV_MPU6050_REG_RAW_ACCEL           0x3B
+#define INV_MPU6050_REG_TEMPERATURE         0x41
+#define INV_MPU6050_REG_RAW_GYRO            0x43
+
+#define INV_MPU6050_REG_USER_CTRL           0x6A
+#define INV_MPU6050_BIT_FIFO_RST                    0x04
+#define INV_MPU6050_BIT_DMP_RST                     0x08
+#define INV_MPU6050_BIT_I2C_MST_EN                  0x20
+#define INV_MPU6050_BIT_FIFO_EN                     0x40
+#define INV_MPU6050_BIT_DMP_EN                      0x80
+
+#define INV_MPU6050_REG_PWR_MGMT_1          0x6B
+#define INV_MPU6050_BIT_H_RESET                     0x80
+#define INV_MPU6050_BIT_SLEEP                       0x40
+#define INV_MPU6050_BIT_CLK_MASK                    0x7
+
+#define INV_MPU6050_REG_PWR_MGMT_2          0x6C
+#define INV_MPU6050_BIT_PWR_ACCL_STBY               0x38
+#define INV_MPU6050_BIT_PWR_GYRO_STBY               0x07
+
+#define INV_MPU6050_REG_FIFO_COUNT_H        0x72
+#define INV_MPU6050_REG_FIFO_R_W            0x74
+
+#define INV_MPU6050_BYTES_PER_3AXIS_SENSOR   6
+#define INV_MPU6050_FIFO_COUNT_BYTE          2
+#define INV_MPU6050_FIFO_THRESHOLD           500
+#define INV_MPU6050_POWER_UP_TIME            100
+#define INV_MPU6050_TEMP_UP_TIME             100
+#define INV_MPU6050_SENSOR_UP_TIME           30
+#define INV_MPU6050_REG_UP_TIME              5
+
+#define INV_MPU6050_TEMP_OFFSET	             12421
+#define INV_MPU6050_TEMP_SCALE               2941
+#define INV_MPU6050_MAX_GYRO_FS_PARAM        3
+#define INV_MPU6050_MAX_ACCL_FS_PARAM        3
+#define INV_MPU6050_THREE_AXIS               3
+#define INV_MPU6050_GYRO_CONFIG_FSR_SHIFT    3
+#define INV_MPU6050_ACCL_CONFIG_FSR_SHIFT    3
+
+/* 6 + 6 round up and plus 8 */
+#define INV_MPU6050_OUTPUT_DATA_SIZE         24
+
+/* init parameters */
+#define INV_MPU6050_INIT_FIFO_RATE           50
+#define INV_MPU6050_TIME_STAMP_TOR                        5
+#define INV_MPU6050_MAX_FIFO_RATE                         1000
+#define INV_MPU6050_MIN_FIFO_RATE                         4
+#define INV_MPU6050_ONE_K_HZ                              1000
+
+/* scan element definition */
+enum inv_mpu6050_scan {
+	INV_MPU6050_SCAN_ACCL_X,
+	INV_MPU6050_SCAN_ACCL_Y,
+	INV_MPU6050_SCAN_ACCL_Z,
+	INV_MPU6050_SCAN_GYRO_X,
+	INV_MPU6050_SCAN_GYRO_Y,
+	INV_MPU6050_SCAN_GYRO_Z,
+	INV_MPU6050_SCAN_TIMESTAMP,
+};
+
+enum inv_mpu6050_filter_e {
+	INV_MPU6050_FILTER_256HZ_NOLPF2 = 0,
+	INV_MPU6050_FILTER_188HZ,
+	INV_MPU6050_FILTER_98HZ,
+	INV_MPU6050_FILTER_42HZ,
+	INV_MPU6050_FILTER_20HZ,
+	INV_MPU6050_FILTER_10HZ,
+	INV_MPU6050_FILTER_5HZ,
+	INV_MPU6050_FILTER_2100HZ_NOLPF,
+	NUM_MPU6050_FILTER
+};
+
+/* IIO attribute address */
+enum INV_MPU6050_IIO_ATTR_ADDR {
+	ATTR_GYRO_MATRIX,
+	ATTR_ACCL_MATRIX,
+};
+
+enum inv_mpu6050_accl_fs_e {
+	INV_MPU6050_FS_02G = 0,
+	INV_MPU6050_FS_04G,
+	INV_MPU6050_FS_08G,
+	INV_MPU6050_FS_16G,
+	NUM_ACCL_FSR
+};
+
+enum inv_mpu6050_fsr_e {
+	INV_MPU6050_FSR_250DPS = 0,
+	INV_MPU6050_FSR_500DPS,
+	INV_MPU6050_FSR_1000DPS,
+	INV_MPU6050_FSR_2000DPS,
+	NUM_MPU6050_FSR
+};
+
+enum inv_mpu6050_clock_sel_e {
+	INV_CLK_INTERNAL = 0,
+	INV_CLK_PLL,
+	NUM_CLK
+};
+
+irqreturn_t inv_mpu6050_irq_handler(int irq, void *p);
+irqreturn_t inv_mpu6050_read_fifo(int irq, void *p);
+int inv_mpu6050_probe_trigger(struct iio_dev *indio_dev);
+void inv_mpu6050_remove_trigger(struct inv_mpu6050_state *st);
+int inv_reset_fifo(struct iio_dev *indio_dev);
+int inv_mpu6050_switch_engine(struct inv_mpu6050_state *st, bool en, u32 mask);
+int inv_mpu6050_write_reg(struct inv_mpu6050_state *st, int reg, u8 val);
+int inv_mpu6050_set_power_itg(struct inv_mpu6050_state *st, bool power_on);
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
new file mode 100644
index 0000000..331781f
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c
@@ -0,0 +1,196 @@
+/*
+* Copyright (C) 2012 Invensense, Inc.
+*
+* This software is licensed under the terms of the GNU General Public
+* License version 2, as published by the Free Software Foundation, and
+* may be copied, distributed, and modified under those terms.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*/
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/sysfs.h>
+#include <linux/jiffies.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/kfifo.h>
+#include <linux/poll.h>
+#include "inv_mpu_iio.h"
+
+int inv_reset_fifo(struct iio_dev *indio_dev)
+{
+	int result;
+	u8 d;
+	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
+
+	/* disable interrupt */
+	result = inv_mpu6050_write_reg(st, st->reg->int_enable, 0);
+	if (result) {
+		dev_err(&st->client->dev, "int_enable failed %d\n", result);
+		return result;
+	}
+	/* disable the sensor output to FIFO */
+	result = inv_mpu6050_write_reg(st, st->reg->fifo_en, 0);
+	if (result)
+		goto reset_fifo_fail;
+	/* disable fifo reading */
+	result = inv_mpu6050_write_reg(st, st->reg->user_ctrl, 0);
+	if (result)
+		goto reset_fifo_fail;
+
+	/* reset FIFO*/
+	result = inv_mpu6050_write_reg(st, st->reg->user_ctrl,
+					INV_MPU6050_BIT_FIFO_RST);
+	if (result)
+		goto reset_fifo_fail;
+	/* enable interrupt */
+	if (st->chip_config.accl_fifo_enable ||
+	    st->chip_config.gyro_fifo_enable) {
+		result = inv_mpu6050_write_reg(st, st->reg->int_enable,
+					INV_MPU6050_BIT_DATA_RDY_EN);
+		if (result)
+			return result;
+	}
+	/* enable FIFO reading and I2C master interface*/
+	result = inv_mpu6050_write_reg(st, st->reg->user_ctrl,
+					INV_MPU6050_BIT_FIFO_EN);
+	if (result)
+		goto reset_fifo_fail;
+	/* enable sensor output to FIFO */
+	d = 0;
+	if (st->chip_config.gyro_fifo_enable)
+		d |= INV_MPU6050_BITS_GYRO_OUT;
+	if (st->chip_config.accl_fifo_enable)
+		d |= INV_MPU6050_BIT_ACCEL_OUT;
+	result = inv_mpu6050_write_reg(st, st->reg->fifo_en, d);
+	if (result)
+		goto reset_fifo_fail;
+
+	return 0;
+
+reset_fifo_fail:
+	dev_err(&st->client->dev, "reset fifo failed %d\n", result);
+	result = inv_mpu6050_write_reg(st, st->reg->int_enable,
+					INV_MPU6050_BIT_DATA_RDY_EN);
+
+	return result;
+}
+
+static void inv_clear_kfifo(struct inv_mpu6050_state *st)
+{
+	unsigned long flags;
+
+	/* take the spin lock sem to avoid interrupt kick in */
+	spin_lock_irqsave(&st->time_stamp_lock, flags);
+	kfifo_reset(&st->timestamps);
+	spin_unlock_irqrestore(&st->time_stamp_lock, flags);
+}
+
+/**
+ * inv_mpu6050_irq_handler() - Cache a timestamp at each data ready interrupt.
+ */
+irqreturn_t inv_mpu6050_irq_handler(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	s64 timestamp;
+
+	timestamp = iio_get_time_ns();
+	spin_lock(&st->time_stamp_lock);
+	kfifo_in(&st->timestamps, &timestamp, 1);
+	spin_unlock(&st->time_stamp_lock);
+
+	return IRQ_WAKE_THREAD;
+}
+
+/**
+ * inv_mpu6050_read_fifo() - Transfer data from hardware FIFO to KFIFO.
+ */
+irqreturn_t inv_mpu6050_read_fifo(int irq, void *p)
+{
+	struct iio_poll_func *pf = p;
+	struct iio_dev *indio_dev = pf->indio_dev;
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	size_t bytes_per_datum;
+	int result;
+	u8 data[INV_MPU6050_OUTPUT_DATA_SIZE];
+	u16 fifo_count;
+	s64 timestamp;
+	u64 *tmp;
+
+	mutex_lock(&indio_dev->mlock);
+	if (!(st->chip_config.accl_fifo_enable |
+		st->chip_config.gyro_fifo_enable))
+		goto end_session;
+	bytes_per_datum = 0;
+	if (st->chip_config.accl_fifo_enable)
+		bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
+
+	if (st->chip_config.gyro_fifo_enable)
+		bytes_per_datum += INV_MPU6050_BYTES_PER_3AXIS_SENSOR;
+
+	/*
+	 * read fifo_count register to know how many bytes inside FIFO
+	 * right now
+	 */
+	result = i2c_smbus_read_i2c_block_data(st->client,
+				       st->reg->fifo_count_h,
+				       INV_MPU6050_FIFO_COUNT_BYTE, data);
+	if (result != INV_MPU6050_FIFO_COUNT_BYTE)
+		goto end_session;
+	fifo_count = be16_to_cpup((__be16 *)(&data[0]));
+	if (fifo_count < bytes_per_datum)
+		goto end_session;
+	/* fifo count can't be odd number, if it is odd, reset fifo*/
+	if (fifo_count & 1)
+		goto flush_fifo;
+	if (fifo_count >  INV_MPU6050_FIFO_THRESHOLD)
+		goto flush_fifo;
+	/* Timestamp mismatch. */
+	if (kfifo_len(&st->timestamps) >
+		fifo_count / bytes_per_datum + INV_MPU6050_TIME_STAMP_TOR)
+			goto flush_fifo;
+	while (fifo_count >= bytes_per_datum) {
+		result = i2c_smbus_read_i2c_block_data(st->client,
+						       st->reg->fifo_r_w,
+						       bytes_per_datum, data);
+		if (result != bytes_per_datum)
+			goto flush_fifo;
+
+		result = kfifo_out(&st->timestamps, &timestamp, 1);
+		/* when there is no timestamp, put timestamp as 0 */
+		if (0 == result)
+			timestamp = 0;
+
+		tmp = (u64 *)data;
+		tmp[DIV_ROUND_UP(bytes_per_datum, 8)] = timestamp;
+		result = iio_push_to_buffers(indio_dev, data);
+		if (result)
+			goto flush_fifo;
+		fifo_count -= bytes_per_datum;
+	}
+
+end_session:
+	mutex_unlock(&indio_dev->mlock);
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+
+flush_fifo:
+	/* Flush HW and SW FIFOs. */
+	inv_reset_fifo(indio_dev);
+	inv_clear_kfifo(st);
+	mutex_unlock(&indio_dev->mlock);
+	iio_trigger_notify_done(indio_dev->trig);
+
+	return IRQ_HANDLED;
+}
diff --git a/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
new file mode 100644
index 0000000..e1d0869
--- /dev/null
+++ b/drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c
@@ -0,0 +1,155 @@
+/*
+* Copyright (C) 2012 Invensense, Inc.
+*
+* This software is licensed under the terms of the GNU General Public
+* License version 2, as published by the Free Software Foundation, and
+* may be copied, distributed, and modified under those terms.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*/
+
+#include "inv_mpu_iio.h"
+
+static void inv_scan_query(struct iio_dev *indio_dev)
+{
+	struct inv_mpu6050_state  *st = iio_priv(indio_dev);
+
+	st->chip_config.gyro_fifo_enable =
+		test_bit(INV_MPU6050_SCAN_GYRO_X,
+			indio_dev->active_scan_mask) ||
+			test_bit(INV_MPU6050_SCAN_GYRO_Y,
+			indio_dev->active_scan_mask) ||
+			test_bit(INV_MPU6050_SCAN_GYRO_Z,
+			indio_dev->active_scan_mask);
+
+	st->chip_config.accl_fifo_enable =
+		test_bit(INV_MPU6050_SCAN_ACCL_X,
+			indio_dev->active_scan_mask) ||
+			test_bit(INV_MPU6050_SCAN_ACCL_Y,
+			indio_dev->active_scan_mask) ||
+			test_bit(INV_MPU6050_SCAN_ACCL_Z,
+			indio_dev->active_scan_mask);
+}
+
+/**
+ *  inv_mpu6050_set_enable() - enable chip functions.
+ *  @indio_dev:	Device driver instance.
+ *  @enable: enable/disable
+ */
+static int inv_mpu6050_set_enable(struct iio_dev *indio_dev, bool enable)
+{
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+	int result;
+
+	if (enable) {
+		result = inv_mpu6050_set_power_itg(st, true);
+		if (result)
+			return result;
+		inv_scan_query(indio_dev);
+		if (st->chip_config.gyro_fifo_enable) {
+			result = inv_mpu6050_switch_engine(st, true,
+					INV_MPU6050_BIT_PWR_GYRO_STBY);
+			if (result)
+				return result;
+		}
+		if (st->chip_config.accl_fifo_enable) {
+			result = inv_mpu6050_switch_engine(st, true,
+					INV_MPU6050_BIT_PWR_ACCL_STBY);
+			if (result)
+				return result;
+		}
+		result = inv_reset_fifo(indio_dev);
+		if (result)
+			return result;
+	} else {
+		result = inv_mpu6050_write_reg(st, st->reg->fifo_en, 0);
+		if (result)
+			return result;
+
+		result = inv_mpu6050_write_reg(st, st->reg->int_enable, 0);
+		if (result)
+			return result;
+
+		result = inv_mpu6050_write_reg(st, st->reg->user_ctrl, 0);
+		if (result)
+			return result;
+
+		result = inv_mpu6050_switch_engine(st, false,
+					INV_MPU6050_BIT_PWR_GYRO_STBY);
+		if (result)
+			return result;
+
+		result = inv_mpu6050_switch_engine(st, false,
+					INV_MPU6050_BIT_PWR_ACCL_STBY);
+		if (result)
+			return result;
+		result = inv_mpu6050_set_power_itg(st, false);
+		if (result)
+			return result;
+	}
+	st->chip_config.enable = enable;
+
+	return 0;
+}
+
+/**
+ * inv_mpu_data_rdy_trigger_set_state() - set data ready interrupt state
+ * @trig: Trigger instance
+ * @state: Desired trigger state
+ */
+static int inv_mpu_data_rdy_trigger_set_state(struct iio_trigger *trig,
+						bool state)
+{
+	return inv_mpu6050_set_enable(trig->private_data, state);
+}
+
+static const struct iio_trigger_ops inv_mpu_trigger_ops = {
+	.owner = THIS_MODULE,
+	.set_trigger_state = &inv_mpu_data_rdy_trigger_set_state,
+};
+
+int inv_mpu6050_probe_trigger(struct iio_dev *indio_dev)
+{
+	int ret;
+	struct inv_mpu6050_state *st = iio_priv(indio_dev);
+
+	st->trig = iio_trigger_alloc("%s-dev%d",
+					indio_dev->name,
+					indio_dev->id);
+	if (st->trig == NULL) {
+		ret = -ENOMEM;
+		goto error_ret;
+	}
+	ret = request_irq(st->client->irq, &iio_trigger_generic_data_rdy_poll,
+				IRQF_TRIGGER_RISING,
+				"inv_mpu",
+				st->trig);
+	if (ret)
+		goto error_free_trig;
+	st->trig->dev.parent = &st->client->dev;
+	st->trig->private_data = indio_dev;
+	st->trig->ops = &inv_mpu_trigger_ops;
+	ret = iio_trigger_register(st->trig);
+	if (ret)
+		goto error_free_irq;
+	indio_dev->trig = st->trig;
+
+	return 0;
+
+error_free_irq:
+	free_irq(st->client->irq, st->trig);
+error_free_trig:
+	iio_trigger_free(st->trig);
+error_ret:
+	return ret;
+}
+
+void inv_mpu6050_remove_trigger(struct inv_mpu6050_state *st)
+{
+	iio_trigger_unregister(st->trig);
+	free_irq(st->client->irq, st->trig);
+	iio_trigger_free(st->trig);
+}