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/*
* Driver for Freescale's 3-Axis Accelerometer MMA8450
*
* Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
*
* 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; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/i2c.h>
#include <linux/input-polldev.h>
#include <linux/of_device.h>
#define MMA8450_DRV_NAME "mma8450"
#define MODE_CHANGE_DELAY_MS 100
#define POLL_INTERVAL 100
#define POLL_INTERVAL_MAX 500
/* register definitions */
#define MMA8450_STATUS 0x00
#define MMA8450_STATUS_ZXYDR 0x08
#define MMA8450_OUT_X8 0x01
#define MMA8450_OUT_Y8 0x02
#define MMA8450_OUT_Z8 0x03
#define MMA8450_OUT_X_LSB 0x05
#define MMA8450_OUT_X_MSB 0x06
#define MMA8450_OUT_Y_LSB 0x07
#define MMA8450_OUT_Y_MSB 0x08
#define MMA8450_OUT_Z_LSB 0x09
#define MMA8450_OUT_Z_MSB 0x0a
#define MMA8450_XYZ_DATA_CFG 0x16
#define MMA8450_CTRL_REG1 0x38
#define MMA8450_CTRL_REG2 0x39
/* mma8450 status */
struct mma8450 {
struct i2c_client *client;
struct input_polled_dev *idev;
};
static int mma8450_read(struct mma8450 *m, unsigned off)
{
struct i2c_client *c = m->client;
int ret;
ret = i2c_smbus_read_byte_data(c, off);
if (ret < 0)
dev_err(&c->dev,
"failed to read register 0x%02x, error %d\n",
off, ret);
return ret;
}
static int mma8450_write(struct mma8450 *m, unsigned off, u8 v)
{
struct i2c_client *c = m->client;
int error;
error = i2c_smbus_write_byte_data(c, off, v);
if (error < 0) {
dev_err(&c->dev,
"failed to write to register 0x%02x, error %d\n",
off, error);
return error;
}
return 0;
}
static int mma8450_read_block(struct mma8450 *m, unsigned off,
u8 *buf, size_t size)
{
struct i2c_client *c = m->client;
int err;
err = i2c_smbus_read_i2c_block_data(c, off, size, buf);
if (err < 0) {
dev_err(&c->dev,
"failed to read block data at 0x%02x, error %d\n",
MMA8450_OUT_X_LSB, err);
return err;
}
return 0;
}
static void mma8450_poll(struct input_polled_dev *dev)
{
struct mma8450 *m = dev->private;
int x, y, z;
int ret;
u8 buf[6];
ret = mma8450_read(m, MMA8450_STATUS);
if (ret < 0)
return;
if (!(ret & MMA8450_STATUS_ZXYDR))
return;
ret = mma8450_read_block(m, MMA8450_OUT_X_LSB, buf, sizeof(buf));
if (ret < 0)
return;
x = ((int)(s8)buf[1] << 4) | (buf[0] & 0xf);
y = ((int)(s8)buf[3] << 4) | (buf[2] & 0xf);
z = ((int)(s8)buf[5] << 4) | (buf[4] & 0xf);
input_report_abs(dev->input, ABS_X, x);
input_report_abs(dev->input, ABS_Y, y);
input_report_abs(dev->input, ABS_Z, z);
input_sync(dev->input);
}
/* Initialize the MMA8450 chip */
static void mma8450_open(struct input_polled_dev *dev)
{
struct mma8450 *m = dev->private;
int err;
/* enable all events from X/Y/Z, no FIFO */
err = mma8450_write(m, MMA8450_XYZ_DATA_CFG, 0x07);
if (err)
return;
/*
* Sleep mode poll rate - 50Hz
* System output data rate - 400Hz
* Full scale selection - Active, +/- 2G
*/
err = mma8450_write(m, MMA8450_CTRL_REG1, 0x01);
if (err < 0)
return;
msleep(MODE_CHANGE_DELAY_MS);
}
static void mma8450_close(struct input_polled_dev *dev)
{
struct mma8450 *m = dev->private;
mma8450_write(m, MMA8450_CTRL_REG1, 0x00);
mma8450_write(m, MMA8450_CTRL_REG2, 0x01);
}
/*
* I2C init/probing/exit functions
*/
static int mma8450_probe(struct i2c_client *c,
const struct i2c_device_id *id)
{
struct input_polled_dev *idev;
struct mma8450 *m;
int err;
m = devm_kzalloc(&c->dev, sizeof(*m), GFP_KERNEL);
if (!m)
return -ENOMEM;
idev = devm_input_allocate_polled_device(&c->dev);
if (!idev)
return -ENOMEM;
m->client = c;
m->idev = idev;
idev->private = m;
idev->input->name = MMA8450_DRV_NAME;
idev->input->id.bustype = BUS_I2C;
idev->poll = mma8450_poll;
idev->poll_interval = POLL_INTERVAL;
idev->poll_interval_max = POLL_INTERVAL_MAX;
idev->open = mma8450_open;
idev->close = mma8450_close;
__set_bit(EV_ABS, idev->input->evbit);
input_set_abs_params(idev->input, ABS_X, -2048, 2047, 32, 32);
input_set_abs_params(idev->input, ABS_Y, -2048, 2047, 32, 32);
input_set_abs_params(idev->input, ABS_Z, -2048, 2047, 32, 32);
err = input_register_polled_device(idev);
if (err) {
dev_err(&c->dev, "failed to register polled input device\n");
return err;
}
i2c_set_clientdata(c, m);
return 0;
}
static const struct i2c_device_id mma8450_id[] = {
{ MMA8450_DRV_NAME, 0 },
{ },
};
MODULE_DEVICE_TABLE(i2c, mma8450_id);
static const struct of_device_id mma8450_dt_ids[] = {
{ .compatible = "fsl,mma8450", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, mma8450_dt_ids);
static struct i2c_driver mma8450_driver = {
.driver = {
.name = MMA8450_DRV_NAME,
.of_match_table = mma8450_dt_ids,
},
.probe = mma8450_probe,
.id_table = mma8450_id,
};
module_i2c_driver(mma8450_driver);
MODULE_AUTHOR("Freescale Semiconductor, Inc.");
MODULE_DESCRIPTION("MMA8450 3-Axis Accelerometer Driver");
MODULE_LICENSE("GPL");
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