--- /dev/null
+/*
+ * MPU3050 Tri-axis gyroscope driver
+ *
+ * Copyright (C) 2011 Wistron Co.Ltd
+ * Joseph Lai <joseph_lai@wistron.com>
+ *
+ * Trimmed down by Alan Cox <alan@linux.intel.com> to produce this version
+ *
+ * This is a 'lite' version of the driver, while we consider the right way
+ * to present the other features to user space. In particular it requires the
+ * device has an IRQ, and it only provides an input interface, so is not much
+ * use for device orientation. A fuller version is available from the Meego
+ * tree.
+ *
+ * This program is based on bma023.c.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/input.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/pm_runtime.h>
+
+#define MPU3050_CHIP_ID_REG 0x00
+#define MPU3050_CHIP_ID 0x69
+#define MPU3050_XOUT_H 0x1D
+#define MPU3050_PWR_MGM 0x3E
+#define MPU3050_PWR_MGM_POS 6
+#define MPU3050_PWR_MGM_MASK 0x40
+
+#define MPU3050_AUTO_DELAY 1000
+
+#define MPU3050_MIN_VALUE -32768
+#define MPU3050_MAX_VALUE 32767
+
+struct axis_data {
+ s16 x;
+ s16 y;
+ s16 z;
+};
+
+struct mpu3050_sensor {
+ struct i2c_client *client;
+ struct device *dev;
+ struct input_dev *idev;
+};
+
+/**
+ * mpu3050_xyz_read_reg - read the axes values
+ * @buffer: provide register addr and get register
+ * @length: length of register
+ *
+ * Reads the register values in one transaction or returns a negative
+ * error code on failure.
+ */
+static int mpu3050_xyz_read_reg(struct i2c_client *client,
+ u8 *buffer, int length)
+{
+ /*
+ * Annoying we can't make this const because the i2c layer doesn't
+ * declare input buffers const.
+ */
+ char cmd = MPU3050_XOUT_H;
+ struct i2c_msg msg[] = {
+ {
+ .addr = client->addr,
+ .flags = 0,
+ .len = 1,
+ .buf = &cmd,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = length,
+ .buf = buffer,
+ },
+ };
+
+ return i2c_transfer(client->adapter, msg, 2);
+}
+
+/**
+ * mpu3050_read_xyz - get co-ordinates from device
+ * @client: i2c address of sensor
+ * @coords: co-ordinates to update
+ *
+ * Return the converted X Y and Z co-ordinates from the sensor device
+ */
+static void mpu3050_read_xyz(struct i2c_client *client,
+ struct axis_data *coords)
+{
+ u16 buffer[3];
+
+ mpu3050_xyz_read_reg(client, (u8 *)buffer, 6);
+ coords->x = be16_to_cpu(buffer[0]);
+ coords->y = be16_to_cpu(buffer[1]);
+ coords->z = be16_to_cpu(buffer[2]);
+ dev_dbg(&client->dev, "%s: x %d, y %d, z %d\n", __func__,
+ coords->x, coords->y, coords->z);
+}
+
+/**
+ * mpu3050_set_power_mode - set the power mode
+ * @client: i2c client for the sensor
+ * @val: value to switch on/off of power, 1: normal power, 0: low power
+ *
+ * Put device to normal-power mode or low-power mode.
+ */
+static void mpu3050_set_power_mode(struct i2c_client *client, u8 val)
+{
+ u8 value;
+
+ value = i2c_smbus_read_byte_data(client, MPU3050_PWR_MGM);
+ value = (value & ~MPU3050_PWR_MGM_MASK) |
+ (((val << MPU3050_PWR_MGM_POS) & MPU3050_PWR_MGM_MASK) ^
+ MPU3050_PWR_MGM_MASK);
+ i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM, value);
+}
+
+/**
+ * mpu3050_input_open - called on input event open
+ * @input: input dev of opened device
+ *
+ * The input layer calls this function when input event is opened. The
+ * function will push the device to resume. Then, the device is ready
+ * to provide data.
+ */
+static int mpu3050_input_open(struct input_dev *input)
+{
+ struct mpu3050_sensor *sensor = input_get_drvdata(input);
+
+ pm_runtime_get(sensor->dev);
+
+ return 0;
+}
+
+/**
+ * mpu3050_input_close - called on input event close
+ * @input: input dev of closed device
+ *
+ * The input layer calls this function when input event is closed. The
+ * function will push the device to suspend.
+ */
+static void mpu3050_input_close(struct input_dev *input)
+{
+ struct mpu3050_sensor *sensor = input_get_drvdata(input);
+
+ pm_runtime_put(sensor->dev);
+}
+
+/**
+ * mpu3050_interrupt_thread - handle an IRQ
+ * @irq: interrupt numner
+ * @data: the sensor
+ *
+ * Called by the kernel single threaded after an interrupt occurs. Read
+ * the sensor data and generate an input event for it.
+ */
+static irqreturn_t mpu3050_interrupt_thread(int irq, void *data)
+{
+ struct mpu3050_sensor *sensor = data;
+ struct axis_data axis;
+
+ mpu3050_read_xyz(sensor->client, &axis);
+
+ input_report_abs(sensor->idev, ABS_X, axis.x);
+ input_report_abs(sensor->idev, ABS_Y, axis.y);
+ input_report_abs(sensor->idev, ABS_Z, axis.z);
+ input_sync(sensor->idev);
+
+ return IRQ_HANDLED;
+}
+
+/**
+ * mpu3050_probe - device detection callback
+ * @client: i2c client of found device
+ * @id: id match information
+ *
+ * The I2C layer calls us when it believes a sensor is present at this
+ * address. Probe to see if this is correct and to validate the device.
+ *
+ * If present install the relevant sysfs interfaces and input device.
+ */
+static int __devinit mpu3050_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct mpu3050_sensor *sensor;
+ struct input_dev *idev;
+ int ret;
+ int error;
+
+ sensor = kzalloc(sizeof(struct mpu3050_sensor), GFP_KERNEL);
+ idev = input_allocate_device();
+ if (!sensor || !idev) {
+ dev_err(&client->dev, "failed to allocate driver data\n");
+ error = -ENOMEM;
+ goto err_free_mem;
+ }
+
+ sensor->client = client;
+ sensor->dev = &client->dev;
+ sensor->idev = idev;
+
+ mpu3050_set_power_mode(client, 1);
+ msleep(10);
+
+ ret = i2c_smbus_read_byte_data(client, MPU3050_CHIP_ID_REG);
+ if (ret < 0) {
+ dev_err(&client->dev, "failed to detect device\n");
+ error = -ENXIO;
+ goto err_free_mem;
+ }
+
+ if (ret != MPU3050_CHIP_ID) {
+ dev_err(&client->dev, "unsupported chip id\n");
+ error = -ENXIO;
+ goto err_free_mem;
+ }
+
+ idev->name = "MPU3050";
+ idev->id.bustype = BUS_I2C;
+ idev->dev.parent = &client->dev;
+
+ idev->open = mpu3050_input_open;
+ idev->close = mpu3050_input_close;
+
+ __set_bit(EV_ABS, idev->evbit);
+ input_set_abs_params(idev, ABS_X,
+ MPU3050_MIN_VALUE, MPU3050_MAX_VALUE, 0, 0);
+ input_set_abs_params(idev, ABS_Y,
+ MPU3050_MIN_VALUE, MPU3050_MAX_VALUE, 0, 0);
+ input_set_abs_params(idev, ABS_Z,
+ MPU3050_MIN_VALUE, MPU3050_MAX_VALUE, 0, 0);
+
+ input_set_drvdata(idev, sensor);
+
+ pm_runtime_set_active(&client->dev);
+
+ error = request_threaded_irq(client->irq,
+ NULL, mpu3050_interrupt_thread,
+ IRQF_TRIGGER_RISING,
+ "mpu_int", sensor);
+ if (error) {
+ dev_err(&client->dev,
+ "can't get IRQ %d, error %d\n", client->irq, error);
+ goto err_pm_set_suspended;
+ }
+
+ error = input_register_device(idev);
+ if (error) {
+ dev_err(&client->dev, "failed to register input device\n");
+ goto err_free_irq;
+ }
+
+ pm_runtime_enable(&client->dev);
+ pm_runtime_set_autosuspend_delay(&client->dev, MPU3050_AUTO_DELAY);
+
+ return 0;
+
+err_free_irq:
+ free_irq(client->irq, sensor);
+err_pm_set_suspended:
+ pm_runtime_set_suspended(&client->dev);
+err_free_mem:
+ input_unregister_device(idev);
+ kfree(sensor);
+ return error;
+}
+
+/**
+ * mpu3050_remove - remove a sensor
+ * @client: i2c client of sensor being removed
+ *
+ * Our sensor is going away, clean up the resources.
+ */
+static int __devexit mpu3050_remove(struct i2c_client *client)
+{
+ struct mpu3050_sensor *sensor = i2c_get_clientdata(client);
+
+ pm_runtime_disable(&client->dev);
+ pm_runtime_set_suspended(&client->dev);
+
+ free_irq(client->irq, sensor);
+ input_unregister_device(sensor->idev);
+ kfree(sensor);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+/**
+ * mpu3050_suspend - called on device suspend
+ * @dev: device being suspended
+ *
+ * Put the device into sleep mode before we suspend the machine.
+ */
+static int mpu3050_suspend(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+
+ mpu3050_set_power_mode(client, 0);
+
+ return 0;
+}
+
+/**
+ * mpu3050_resume - called on device resume
+ * @dev: device being resumed
+ *
+ * Put the device into powered mode on resume.
+ */
+static int mpu3050_resume(struct device *dev)
+{
+ struct i2c_client *client = to_i2c_client(dev);
+
+ mpu3050_set_power_mode(client, 1);
+ msleep(100); /* wait for gyro chip resume */
+
+ return 0;
+}
+#endif
+
+static UNIVERSAL_DEV_PM_OPS(mpu3050_pm, mpu3050_suspend, mpu3050_resume, NULL);
+
+static const struct i2c_device_id mpu3050_ids[] = {
+ { "mpu3050", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, mpu3050_ids);
+
+static struct i2c_driver mpu3050_i2c_driver = {
+ .driver = {
+ .name = "mpu3050",
+ .owner = THIS_MODULE,
+ .pm = &mpu3050_pm,
+ },
+ .probe = mpu3050_probe,
+ .remove = __devexit_p(mpu3050_remove),
+ .id_table = mpu3050_ids,
+};
+
+static int __init mpu3050_init(void)
+{
+ return i2c_add_driver(&mpu3050_i2c_driver);
+}
+module_init(mpu3050_init);
+
+static void __exit mpu3050_exit(void)
+{
+ i2c_del_driver(&mpu3050_i2c_driver);
+}
+module_exit(mpu3050_exit);
+
+MODULE_AUTHOR("Wistron Corp.");
+MODULE_DESCRIPTION("MPU3050 Tri-axis gyroscope driver");
+MODULE_LICENSE("GPL");