Invensense MPU6050 Device Driver.

This the basic functional Invensense MPU6050 Device driver.
Signed-off-by: Ge Gao <ggao@invensense.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Documentation/ABI/testing/sysfs-bus-iio-mpu6050

+What:           /sys/bus/iio/devices/iio:deviceX/in_gyro_matrix
+What:           /sys/bus/iio/devices/iio:deviceX/in_accel_matrix
+What:           /sys/bus/iio/devices/iio:deviceX/in_magn_matrix
+KernelVersion:  3.4.0
+Contact:        linux-iio@vger.kernel.org
+Description:
+		This is mounting matrix for motion sensors. Mounting matrix
+		is a 3x3 unitary matrix. A typical mounting matrix would look like
+		[0, 1, 0; 1, 0, 0; 0, 0, -1]. Using this information, it would be
+		easy to tell the relative positions among sensors as well as their
+		positions relative to the board that holds these sensors. Identity matrix
+		[1, 0, 0; 0, 1, 0; 0, 0, 1] means sensor chip and device are perfectly
+		aligned with each other. All axes are exactly the same.

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"

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/

drivers/iio/imu/inv_mpu6050/Kconfig

+#
+# 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.

drivers/iio/imu/inv_mpu6050/Makefile

+#
+# 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

drivers/iio/imu/inv_mpu6050/inv_mpu_iio.h

+/*
+* 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);

drivers/iio/imu/inv_mpu6050/inv_mpu_ring.c

+/*
+* 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;
+}

drivers/iio/imu/inv_mpu6050/inv_mpu_trigger.c

+/*
+* 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);
+}

include/linux/platform_data/invensense_mpu6050.h

+/*
+* 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.
+*/
+
+#ifndef __INV_MPU6050_PLATFORM_H_
+#define __INV_MPU6050_PLATFORM_H_
+
+/**
+ * struct inv_mpu6050_platform_data - Platform data for the mpu driver
+ * @orientation:	Orientation matrix of the chip
+ *
+ * Contains platform specific information on how to configure the MPU6050 to
+ * work on this platform.  The orientation matricies are 3x3 rotation matricies
+ * that are applied to the data to rotate from the mounting orientation to the
+ * platform orientation.  The values must be one of 0, 1, or -1 and each row and
+ * column should have exactly 1 non-zero value.
+ */
+struct inv_mpu6050_platform_data {
+	__s8 orientation[9];
+};
+
+#endif