- 根目录:
- drivers
- input
- misc
- mpu3050.c
/*
* 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 0x69
#define MPU3050_AUTO_DELAY 1000
#define MPU3050_MIN_VALUE -32768
#define MPU3050_MAX_VALUE 32767
#define MPU3050_DEFAULT_POLL_INTERVAL 200
#define MPU3050_DEFAULT_FS_RANGE 3
/* Register map */
#define MPU3050_CHIP_ID_REG 0x00
#define MPU3050_SMPLRT_DIV 0x15
#define MPU3050_DLPF_FS_SYNC 0x16
#define MPU3050_INT_CFG 0x17
#define MPU3050_XOUT_H 0x1D
#define MPU3050_PWR_MGM 0x3E
#define MPU3050_PWR_MGM_POS 6
/* Register bits */
/* DLPF_FS_SYNC */
#define MPU3050_EXT_SYNC_NONE 0x00
#define MPU3050_EXT_SYNC_TEMP 0x20
#define MPU3050_EXT_SYNC_GYROX 0x40
#define MPU3050_EXT_SYNC_GYROY 0x60
#define MPU3050_EXT_SYNC_GYROZ 0x80
#define MPU3050_EXT_SYNC_ACCELX 0xA0
#define MPU3050_EXT_SYNC_ACCELY 0xC0
#define MPU3050_EXT_SYNC_ACCELZ 0xE0
#define MPU3050_EXT_SYNC_MASK 0xE0
#define MPU3050_FS_250DPS 0x00
#define MPU3050_FS_500DPS 0x08
#define MPU3050_FS_1000DPS 0x10
#define MPU3050_FS_2000DPS 0x18
#define MPU3050_FS_MASK 0x18
#define MPU3050_DLPF_CFG_256HZ_NOLPF2 0x00
#define MPU3050_DLPF_CFG_188HZ 0x01
#define MPU3050_DLPF_CFG_98HZ 0x02
#define MPU3050_DLPF_CFG_42HZ 0x03
#define MPU3050_DLPF_CFG_20HZ 0x04
#define MPU3050_DLPF_CFG_10HZ 0x05
#define MPU3050_DLPF_CFG_5HZ 0x06
#define MPU3050_DLPF_CFG_2100HZ_NOLPF 0x07
#define MPU3050_DLPF_CFG_MASK 0x07
/* INT_CFG */
#define MPU3050_RAW_RDY_EN 0x01
#define MPU3050_MPU_RDY_EN 0x02
#define MPU3050_LATCH_INT_EN 0x04
/* PWR_MGM */
#define MPU3050_PWR_MGM_PLL_X 0x01
#define MPU3050_PWR_MGM_PLL_Y 0x02
#define MPU3050_PWR_MGM_PLL_Z 0x03
#define MPU3050_PWR_MGM_CLKSEL 0x07
#define MPU3050_PWR_MGM_STBY_ZG 0x08
#define MPU3050_PWR_MGM_STBY_YG 0x10
#define MPU3050_PWR_MGM_STBY_XG 0x20
#define MPU3050_PWR_MGM_SLEEP 0x40
#define MPU3050_PWR_MGM_RESET 0x80
#define MPU3050_PWR_MGM_MASK 0x40
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);
int error;
pm_runtime_get(sensor->dev);
/* Enable interrupts */
error = i2c_smbus_write_byte_data(sensor->client, MPU3050_INT_CFG,
MPU3050_LATCH_INT_EN |
MPU3050_RAW_RDY_EN |
MPU3050_MPU_RDY_EN);
if (error < 0) {
pm_runtime_put(sensor->dev);
return error;
}
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_hw_init - initialize hardware
* @sensor: the sensor
*
* Called during device probe; configures the sampling method.
*/
static int mpu3050_hw_init(struct mpu3050_sensor *sensor)
{
struct i2c_client *client = sensor->client;
int ret;
u8 reg;
/* Reset */
ret = i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM,
MPU3050_PWR_MGM_RESET);
if (ret < 0)
return ret;
ret = i2c_smbus_read_byte_data(client, MPU3050_PWR_MGM);
if (ret < 0)
return ret;
ret &= ~MPU3050_PWR_MGM_CLKSEL;
ret |= MPU3050_PWR_MGM_PLL_Z;
ret = i2c_smbus_write_byte_data(client, MPU3050_PWR_MGM, ret);
if (ret < 0)
return ret;
/* Output frequency divider. The poll interval */
ret = i2c_smbus_write_byte_data(client, MPU3050_SMPLRT_DIV,
MPU3050_DEFAULT_POLL_INTERVAL - 1);
if (ret < 0)
return ret;
/* Set low pass filter and full scale */
reg = MPU3050_DEFAULT_FS_RANGE;
reg |= MPU3050_DLPF_CFG_42HZ << 3;
reg |= MPU3050_EXT_SYNC_NONE << 5;
ret = i2c_smbus_write_byte_data(client, MPU3050_DLPF_FS_SYNC, reg);
if (ret < 0)
return ret;
return 0;
}
/**
* 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 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 = mpu3050_hw_init(sensor);
if (error)
goto err_pm_set_suspended;
error = request_threaded_irq(client->irq,
NULL, mpu3050_interrupt_thread,
IRQF_TRIGGER_RISING | IRQF_ONESHOT,
"mpu3050", 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_free_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 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 const struct of_device_id mpu3050_of_match[] = {
{ .compatible = "invn,mpu3050", },
{ },
};
MODULE_DEVICE_TABLE(of, mpu3050_of_match);
static struct i2c_driver mpu3050_i2c_driver = {
.driver = {
.name = "mpu3050",
.owner = THIS_MODULE,
.pm = &mpu3050_pm,
.of_match_table = mpu3050_of_match,
},
.probe = mpu3050_probe,
.remove = mpu3050_remove,
.id_table = mpu3050_ids,
};
module_i2c_driver(mpu3050_i2c_driver);
MODULE_AUTHOR("Wistron Corp.");
MODULE_DESCRIPTION("MPU3050 Tri-axis gyroscope driver");
MODULE_LICENSE("GPL");