// SPDX-License-Identifier: GPL-2.0-only
/*
* Freescale MMA7660FC 3-Axis Accelerometer
*
* Copyright (c) 2016, Intel Corporation.
*
* IIO driver for Freescale MMA7660FC; 7-bit I2C address: 0x4c.
*/
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#define MMA7660_DRIVER_NAME "mma7660"
#define MMA7660_REG_XOUT 0x00
#define MMA7660_REG_YOUT 0x01
#define MMA7660_REG_ZOUT 0x02
#define MMA7660_REG_OUT_BIT_ALERT BIT(6)
#define MMA7660_REG_MODE 0x07
#define MMA7660_REG_MODE_BIT_MODE BIT(0)
#define MMA7660_REG_MODE_BIT_TON BIT(2)
#define MMA7660_I2C_READ_RETRIES 5
/*
* The accelerometer has one measurement range:
*
* -1.5g - +1.5g (6-bit, signed)
*
* scale = (1.5 + 1.5) * 9.81 / (2^6 - 1) = 0.467142857
*/
#define MMA7660_SCALE_AVAIL "0.467142857"
static const int mma7660_nscale = 467142857;
enum mma7660_mode {
MMA7660_MODE_STANDBY,
MMA7660_MODE_ACTIVE
};
struct mma7660_data {
struct i2c_client *client;
struct mutex lock;
enum mma7660_mode mode;
struct iio_mount_matrix orientation;
};
static const struct iio_mount_matrix *
mma7660_get_mount_matrix(const struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct mma7660_data *data = iio_priv(indio_dev);
return &data->orientation;
}
static const struct iio_chan_spec_ext_info mma7660_ext_info[] = {
IIO_MOUNT_MATRIX(IIO_SHARED_BY_DIR, mma7660_get_mount_matrix),
{ }
};
static IIO_CONST_ATTR(in_accel_scale_available, MMA7660_SCALE_AVAIL);
static struct attribute *mma7660_attributes[] = {
&iio_const_attr_in_accel_scale_available.dev_attr.attr,
NULL,
};
static const struct attribute_group mma7660_attribute_group = {
.attrs = mma7660_attributes
};
#define MMA7660_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), \
.ext_info = mma7660_ext_info, \
}
static const struct iio_chan_spec mma7660_channels[] = {
MMA7660_CHANNEL(MMA7660_REG_XOUT, X),
MMA7660_CHANNEL(MMA7660_REG_YOUT, Y),
MMA7660_CHANNEL(MMA7660_REG_ZOUT, Z),
};
static int mma7660_set_mode(struct mma7660_data *data,
enum mma7660_mode mode)
{
int ret;
struct i2c_client *client = data->client;
if (mode == data->mode)
return 0;
ret = i2c_smbus_read_byte_data(client, MMA7660_REG_MODE);
if (ret < 0) {
dev_err(&client->dev, "failed to read sensor mode\n");
return ret;
}
if (mode == MMA7660_MODE_ACTIVE) {
ret &= ~MMA7660_REG_MODE_BIT_TON;
ret |= MMA7660_REG_MODE_BIT_MODE;
} else {
ret &= ~MMA7660_REG_MODE_BIT_TON;
ret &= ~MMA7660_REG_MODE_BIT_MODE;
}
ret = i2c_smbus_write_byte_data(client, MMA7660_REG_MODE, ret);
if (ret < 0) {
dev_err(&client->dev, "failed to change sensor mode\n");
return ret;
}
data->mode = mode;
return ret;
}
static int mma7660_read_accel(struct mma7660_data *data, u8 address)
{
int ret, retries = MMA7660_I2C_READ_RETRIES;
struct i2c_client *client = data->client;
/*
* Read data. If the Alert bit is set, the register was read at
* the same time as the device was attempting to update the content.
* The solution is to read the register again. Do this only
* MMA7660_I2C_READ_RETRIES times to avoid spending too much time
* in the kernel.
*/
do {
ret = i2c_smbus_read_byte_data(client, address);
if (ret < 0) {
dev_err(&client->dev, "register read failed\n");
return ret;
}
} while (retries-- > 0 && ret & MMA7660_REG_OUT_BIT_ALERT);
if (ret & MMA7660_REG_OUT_BIT_ALERT) {
dev_err(&client->dev, "all register read retries failed\n");
return -ETIMEDOUT;
}
return ret;
}
static int mma7660_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mma7660_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&data->lock);
ret = mma7660_read_accel(data, chan->address);
mutex_unlock(&data->lock);
if (ret < 0)
return ret;
*val = sign_extend32(ret, 5);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = 0;
*val2 = mma7660_nscale;
return IIO_VAL_INT_PLUS_NANO;
default:
return -EINVAL;
}
return -EINVAL;
}
static const struct iio_info mma7660_info = {
.read_raw = mma7660_read_raw,
.attrs = &mma7660_attribute_group,
};
static int mma7660_probe(struct i2c_client *client)
{
int ret;
struct iio_dev *indio_dev;
struct mma7660_data *data;
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);
mutex_init(&data->lock);
data->mode = MMA7660_MODE_STANDBY;
ret = iio_read_mount_matrix(&client->dev, &data->orientation);
if (ret)
return ret;
indio_dev->info = &mma7660_info;
indio_dev->name = MMA7660_DRIVER_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = mma7660_channels;
indio_dev->num_channels = ARRAY_SIZE(mma7660_channels);
ret = mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");
mma7660_set_mode(data, MMA7660_MODE_STANDBY);
}
return ret;
}
static void mma7660_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
int ret;
iio_device_unregister(indio_dev);
ret = mma7660_set_mode(iio_priv(indio_dev), MMA7660_MODE_STANDBY);
if (ret)
dev_warn(&client->dev, "Failed to put device in stand-by mode (%pe), ignoring\n",
ERR_PTR(ret));
}
static int mma7660_suspend(struct device *dev)
{
struct mma7660_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return mma7660_set_mode(data, MMA7660_MODE_STANDBY);
}
static int mma7660_resume(struct device *dev)
{
struct mma7660_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return mma7660_set_mode(data, MMA7660_MODE_ACTIVE);
}
static DEFINE_SIMPLE_DEV_PM_OPS(mma7660_pm_ops, mma7660_suspend,
mma7660_resume);
static const struct i2c_device_id mma7660_i2c_id[] = {
{ "mma7660" },
{}
};
MODULE_DEVICE_TABLE(i2c, mma7660_i2c_id);
static const struct of_device_id mma7660_of_match[] = {
{ .compatible = "fsl,mma7660" },
{ }
};
MODULE_DEVICE_TABLE(of, mma7660_of_match);
static const struct acpi_device_id mma7660_acpi_id[] = {
{"MMA7660", 0},
{}
};
MODULE_DEVICE_TABLE(acpi, mma7660_acpi_id);
static struct i2c_driver mma7660_driver = {
.driver = {
.name = "mma7660",
.pm = pm_sleep_ptr(&mma7660_pm_ops),
.of_match_table = mma7660_of_match,
.acpi_match_table = mma7660_acpi_id,
},
.probe = mma7660_probe,
.remove = mma7660_remove,
.id_table = mma7660_i2c_id,
};
module_i2c_driver(mma7660_driver);
MODULE_AUTHOR("Constantin Musca <[email protected]>");
MODULE_DESCRIPTION("Freescale MMA7660FC 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");
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