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/**
* IIO driver for the MiraMEMS DA280 3-axis accelerometer and
* IIO driver for the MiraMEMS DA226 2-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 and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/byteorder/generic.h>
#define DA280_REG_CHIP_ID 0x01
#define DA280_REG_ACC_X_LSB 0x02
#define DA280_REG_ACC_Y_LSB 0x04
#define DA280_REG_ACC_Z_LSB 0x06
#define DA280_REG_MODE_BW 0x11
#define DA280_CHIP_ID 0x13
#define DA280_MODE_ENABLE 0x1e
#define DA280_MODE_DISABLE 0x9e
enum { da226, da280 };
/*
* a value of + or -4096 corresponds to + or - 1G
* scale = 9.81 / 4096 = 0.002395019
*/
static const int da280_nscale = 2395019;
#define DA280_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 da280_channels[] = {
DA280_CHANNEL(DA280_REG_ACC_X_LSB, X),
DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y),
DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z),
};
struct da280_data {
struct i2c_client *client;
};
static int da280_enable(struct i2c_client *client, bool enable)
{
u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE;
return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data);
}
static int da280_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct da280_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = i2c_smbus_read_word_data(data->client, chan->address);
if (ret < 0)
return ret;
/*
* Values are 14 bits, stored as 16 bits with the 2
* least significant bits always 0.
*/
*val = (short)ret >> 2;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = da280_nscale;
return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
}
static const struct iio_info da280_info = {
.read_raw = da280_read_raw,
};
static int da280_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct da280_data *data;
ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID);
if (ret != DA280_CHIP_ID)
return (ret < 0) ? ret : -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
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 = &da280_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = da280_channels;
if (id->driver_data == da226) {
indio_dev->name = "da226";
indio_dev->num_channels = 2;
} else {
indio_dev->name = "da280";
indio_dev->num_channels = 3;
}
ret = da280_enable(client, true);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");
da280_enable(client, false);
}
return ret;
}
static int da280_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
return da280_enable(client, false);
}
#ifdef CONFIG_PM_SLEEP
static int da280_suspend(struct device *dev)
{
return da280_enable(to_i2c_client(dev), false);
}
static int da280_resume(struct device *dev)
{
return da280_enable(to_i2c_client(dev), true);
}
#endif
static SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume);
static const struct i2c_device_id da280_i2c_id[] = {
{ "da226", da226 },
{ "da280", da280 },
{}
};
MODULE_DEVICE_TABLE(i2c, da280_i2c_id);
static struct i2c_driver da280_driver = {
.driver = {
.name = "da280",
.pm = &da280_pm_ops,
},
.probe = da280_probe,
.remove = da280_remove,
.id_table = da280_i2c_id,
};
module_i2c_driver(da280_driver);
MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");
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