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* MPU3050 Tri-axis gyroscope driver
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* Copyright (C) 2011 Wistron Co.Ltd
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* Joseph Lai <joseph_lai@wistron.com>
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* Trimmed down by Alan Cox <alan@linux.intel.com> to produce this version
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* This is a 'lite' version of the driver, while we consider the right way
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* to present the other features to user space. In particular it requires the
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* device has an IRQ, and it only provides an input interface, so is not much
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* use for device orientation. A fuller version is available from the Meego
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* This program is based on bma023.c.
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public License along
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* with this program; if not, write to the Free Software Foundation, Inc.,
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* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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#include <linux/module.h>
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/platform_device.h>
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#include <linux/mutex.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/input.h>
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#include <linux/delay.h>
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#include <linux/slab.h>
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#include <linux/pm_runtime.h>
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#define MPU3050_CHIP_ID_REG 0x00
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#define MPU3050_CHIP_ID 0x69
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#define MPU3050_XOUT_H 0x1D
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#define MPU3050_PWR_MGM 0x3E
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#define MPU3050_PWR_MGM_POS 6
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#define MPU3050_PWR_MGM_MASK 0x40
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#define MPU3050_AUTO_DELAY 1000
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#define MPU3050_MIN_VALUE -32768
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#define MPU3050_MAX_VALUE 32767
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struct mpu3050_sensor {
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struct i2c_client *client;
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struct input_dev *idev;
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* mpu3050_xyz_read_reg - read the axes values
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* @buffer: provide register addr and get register
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* @length: length of register
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* Reads the register values in one transaction or returns a negative
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* error code on failure.
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static int mpu3050_xyz_read_reg(struct i2c_client *client,
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u8 *buffer, int length)
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* Annoying we can't make this const because the i2c layer doesn't
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* declare input buffers const.
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char cmd = MPU3050_XOUT_H;
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struct i2c_msg msg[] = {
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return i2c_transfer(client->adapter, msg, 2);
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* mpu3050_read_xyz - get co-ordinates from device
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* @client: i2c address of sensor
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* @coords: co-ordinates to update
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* Return the converted X Y and Z co-ordinates from the sensor device
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static void mpu3050_read_xyz(struct i2c_client *client,
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struct axis_data *coords)
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mpu3050_xyz_read_reg(client, (u8 *)buffer, 6);
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coords->x = be16_to_cpu(buffer[0]);
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coords->y = be16_to_cpu(buffer[1]);
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coords->z = be16_to_cpu(buffer[2]);
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dev_dbg(&client->dev, "%s: x %d, y %d, z %d\n", __func__,
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coords->x, coords->y, coords->z);
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* mpu3050_set_power_mode - set the power mode
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* @client: i2c client for the sensor
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* @val: value to switch on/off of power, 1: normal power, 0: low power
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* Put device to normal-power mode or low-power mode.
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static void mpu3050_set_power_mode(struct i2c_client *client, u8 val)
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value = i2c_smbus_read_byte_data(client, MPU3050_PWR_MGM);
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value = (value & ~MPU3050_PWR_MGM_MASK) |
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(((val << MPU3050_PWR_MGM_POS) & MPU3050_PWR_MGM_MASK) ^
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MPU3050_PWR_MGM_MASK);
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i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM, value);
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* mpu3050_input_open - called on input event open
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* @input: input dev of opened device
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* The input layer calls this function when input event is opened. The
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* function will push the device to resume. Then, the device is ready
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static int mpu3050_input_open(struct input_dev *input)
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struct mpu3050_sensor *sensor = input_get_drvdata(input);
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pm_runtime_get(sensor->dev);
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* mpu3050_input_close - called on input event close
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* @input: input dev of closed device
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* The input layer calls this function when input event is closed. The
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* function will push the device to suspend.
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static void mpu3050_input_close(struct input_dev *input)
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struct mpu3050_sensor *sensor = input_get_drvdata(input);
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pm_runtime_put(sensor->dev);
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* mpu3050_interrupt_thread - handle an IRQ
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* @irq: interrupt numner
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* Called by the kernel single threaded after an interrupt occurs. Read
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* the sensor data and generate an input event for it.
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static irqreturn_t mpu3050_interrupt_thread(int irq, void *data)
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struct mpu3050_sensor *sensor = data;
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struct axis_data axis;
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mpu3050_read_xyz(sensor->client, &axis);
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input_report_abs(sensor->idev, ABS_X, axis.x);
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input_report_abs(sensor->idev, ABS_Y, axis.y);
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input_report_abs(sensor->idev, ABS_Z, axis.z);
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input_sync(sensor->idev);
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* mpu3050_probe - device detection callback
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* @client: i2c client of found device
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* @id: id match information
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* The I2C layer calls us when it believes a sensor is present at this
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* address. Probe to see if this is correct and to validate the device.
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* If present install the relevant sysfs interfaces and input device.
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static int __devinit mpu3050_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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struct mpu3050_sensor *sensor;
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struct input_dev *idev;
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sensor = kzalloc(sizeof(struct mpu3050_sensor), GFP_KERNEL);
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idev = input_allocate_device();
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if (!sensor || !idev) {
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dev_err(&client->dev, "failed to allocate driver data\n");
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sensor->client = client;
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sensor->dev = &client->dev;
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mpu3050_set_power_mode(client, 1);
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ret = i2c_smbus_read_byte_data(client, MPU3050_CHIP_ID_REG);
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dev_err(&client->dev, "failed to detect device\n");
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if (ret != MPU3050_CHIP_ID) {
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dev_err(&client->dev, "unsupported chip id\n");
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idev->name = "MPU3050";
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idev->id.bustype = BUS_I2C;
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idev->dev.parent = &client->dev;
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idev->open = mpu3050_input_open;
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idev->close = mpu3050_input_close;
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__set_bit(EV_ABS, idev->evbit);
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input_set_abs_params(idev, ABS_X,
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MPU3050_MIN_VALUE, MPU3050_MAX_VALUE, 0, 0);
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input_set_abs_params(idev, ABS_Y,
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MPU3050_MIN_VALUE, MPU3050_MAX_VALUE, 0, 0);
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input_set_abs_params(idev, ABS_Z,
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MPU3050_MIN_VALUE, MPU3050_MAX_VALUE, 0, 0);
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input_set_drvdata(idev, sensor);
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pm_runtime_set_active(&client->dev);
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error = request_threaded_irq(client->irq,
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NULL, mpu3050_interrupt_thread,
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dev_err(&client->dev,
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"can't get IRQ %d, error %d\n", client->irq, error);
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goto err_pm_set_suspended;
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error = input_register_device(idev);
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dev_err(&client->dev, "failed to register input device\n");
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pm_runtime_enable(&client->dev);
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pm_runtime_set_autosuspend_delay(&client->dev, MPU3050_AUTO_DELAY);
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free_irq(client->irq, sensor);
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err_pm_set_suspended:
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pm_runtime_set_suspended(&client->dev);
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input_free_device(idev);
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* mpu3050_remove - remove a sensor
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* @client: i2c client of sensor being removed
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* Our sensor is going away, clean up the resources.
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static int __devexit mpu3050_remove(struct i2c_client *client)
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struct mpu3050_sensor *sensor = i2c_get_clientdata(client);
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pm_runtime_disable(&client->dev);
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pm_runtime_set_suspended(&client->dev);
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free_irq(client->irq, sensor);
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input_unregister_device(sensor->idev);
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* mpu3050_suspend - called on device suspend
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* @dev: device being suspended
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* Put the device into sleep mode before we suspend the machine.
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static int mpu3050_suspend(struct device *dev)
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struct i2c_client *client = to_i2c_client(dev);
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mpu3050_set_power_mode(client, 0);
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* mpu3050_resume - called on device resume
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* @dev: device being resumed
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* Put the device into powered mode on resume.
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static int mpu3050_resume(struct device *dev)
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struct i2c_client *client = to_i2c_client(dev);
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mpu3050_set_power_mode(client, 1);
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msleep(100); /* wait for gyro chip resume */
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static UNIVERSAL_DEV_PM_OPS(mpu3050_pm, mpu3050_suspend, mpu3050_resume, NULL);
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static const struct i2c_device_id mpu3050_ids[] = {
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MODULE_DEVICE_TABLE(i2c, mpu3050_ids);
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static struct i2c_driver mpu3050_i2c_driver = {
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.owner = THIS_MODULE,
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.probe = mpu3050_probe,
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.remove = __devexit_p(mpu3050_remove),
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.id_table = mpu3050_ids,
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static int __init mpu3050_init(void)
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return i2c_add_driver(&mpu3050_i2c_driver);
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module_init(mpu3050_init);
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static void __exit mpu3050_exit(void)
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i2c_del_driver(&mpu3050_i2c_driver);
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module_exit(mpu3050_exit);
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MODULE_AUTHOR("Wistron Corp.");
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MODULE_DESCRIPTION("MPU3050 Tri-axis gyroscope driver");
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MODULE_LICENSE("GPL");