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/**
* mCube MC3230 3-Axis Accelerometer
*
* Copyright (c) 2016 Hans de Goede <hdegoede@redhat.com>
*
* 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.
*
* IIO driver for mCube MC3230; 7-bit I2C address: 0x4c.
*/
#include <linux/i2c.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#define MC3230_REG_XOUT 0x00
#define MC3230_REG_YOUT 0x01
#define MC3230_REG_ZOUT 0x02
#define MC3230_REG_MODE 0x07
#define MC3230_MODE_OPCON_MASK 0x03
#define MC3230_MODE_OPCON_WAKE 0x01
#define MC3230_MODE_OPCON_STANDBY 0x03
#define MC3230_REG_CHIP_ID 0x18
#define MC3230_CHIP_ID 0x01
#define MC3230_REG_PRODUCT_CODE 0x3b
#define MC3230_PRODUCT_CODE 0x19
/*
* The accelerometer has one measurement range:
*
* -1.5g - +1.5g (8-bit, signed)
*
* scale = (1.5 + 1.5) * 9.81 / (2^8 - 1) = 0.115411765
*/
static const int mc3230_nscale = 115411765;
#define MC3230_CHANNEL(reg, axis) { \
.type = IIO_ACCEL, \
.address = reg, \
.modified = 1, \
.channel2 = IIO_MOD_##axis, \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
}
static const struct iio_chan_spec mc3230_channels[] = {
MC3230_CHANNEL(MC3230_REG_XOUT, X),
MC3230_CHANNEL(MC3230_REG_YOUT, Y),
MC3230_CHANNEL(MC3230_REG_ZOUT, Z),
};
struct mc3230_data {
struct i2c_client *client;
};
static int mc3230_set_opcon(struct mc3230_data *data, int opcon)
{
int ret;
struct i2c_client *client = data->client;
ret = i2c_smbus_read_byte_data(client, MC3230_REG_MODE);
if (ret < 0) {
dev_err(&client->dev, "failed to read mode reg: %d\n", ret);
return ret;
}
ret &= ~MC3230_MODE_OPCON_MASK;
ret |= opcon;
ret = i2c_smbus_write_byte_data(client, MC3230_REG_MODE, ret);
if (ret < 0) {
dev_err(&client->dev, "failed to write mode reg: %d\n", ret);
return ret;
}
return 0;
}
static int mc3230_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mc3230_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = i2c_smbus_read_byte_data(data->client, chan->address);
if (ret < 0)
return ret;
*val = sign_extend32(ret, 7);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = mc3230_nscale;
return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
}
static const struct iio_info mc3230_info = {
.read_raw = mc3230_read_raw,
};
static int mc3230_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct mc3230_data *data;
/* First check chip-id and product-id */
ret = i2c_smbus_read_byte_data(client, MC3230_REG_CHIP_ID);
if (ret != MC3230_CHIP_ID)
return (ret < 0) ? ret : -ENODEV;
ret = i2c_smbus_read_byte_data(client, MC3230_REG_PRODUCT_CODE);
if (ret != MC3230_PRODUCT_CODE)
return (ret < 0) ? ret : -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev) {
dev_err(&client->dev, "iio allocation failed!\n");
return -ENOMEM;
}
data = iio_priv(indio_dev);
data->client = client;
i2c_set_clientdata(client, indio_dev);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &mc3230_info;
indio_dev->name = "mc3230";
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = mc3230_channels;
indio_dev->num_channels = ARRAY_SIZE(mc3230_channels);
ret = mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");
mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
}
return ret;
}
static int mc3230_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
return mc3230_set_opcon(iio_priv(indio_dev), MC3230_MODE_OPCON_STANDBY);
}
#ifdef CONFIG_PM_SLEEP
static int mc3230_suspend(struct device *dev)
{
struct mc3230_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return mc3230_set_opcon(data, MC3230_MODE_OPCON_STANDBY);
}
static int mc3230_resume(struct device *dev)
{
struct mc3230_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return mc3230_set_opcon(data, MC3230_MODE_OPCON_WAKE);
}
#endif
static SIMPLE_DEV_PM_OPS(mc3230_pm_ops, mc3230_suspend, mc3230_resume);
static const struct i2c_device_id mc3230_i2c_id[] = {
{"mc3230", 0},
{}
};
MODULE_DEVICE_TABLE(i2c, mc3230_i2c_id);
static struct i2c_driver mc3230_driver = {
.driver = {
.name = "mc3230",
.pm = &mc3230_pm_ops,
},
.probe = mc3230_probe,
.remove = mc3230_remove,
.id_table = mc3230_i2c_id,
};
module_i2c_driver(mc3230_driver);
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("mCube MC3230 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");
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