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OpenCloudOS-Kernel/drivers/iio/accel/stk8312.c

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/**
* Sensortek STK8312 3-Axis Accelerometer
*
* Copyright (c) 2015, Intel Corporation.
*
* This file is subject to the terms and conditions of version 2 of
* the GNU General Public License. See the file COPYING in the main
* directory of this archive for more details.
*
* IIO driver for STK8312; 7-bit I2C address: 0x3D.
*/
#include <linux/acpi.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#define STK8312_REG_XOUT 0x00
#define STK8312_REG_YOUT 0x01
#define STK8312_REG_ZOUT 0x02
#define STK8312_REG_MODE 0x07
#define STK8312_REG_STH 0x13
#define STK8312_REG_RESET 0x20
#define STK8312_REG_AFECTRL 0x24
#define STK8312_REG_OTPADDR 0x3D
#define STK8312_REG_OTPDATA 0x3E
#define STK8312_REG_OTPCTRL 0x3F
#define STK8312_MODE_ACTIVE 1
#define STK8312_MODE_STANDBY 0
#define STK8312_MODE_MASK 0x01
#define STK8312_RNG_MASK 0xC0
#define STK8312_RNG_SHIFT 6
#define STK8312_READ_RETRIES 16
#define STK8312_DRIVER_NAME "stk8312"
/*
* The accelerometer has two measurement ranges:
*
* -6g - +6g (8-bit, signed)
* -16g - +16g (8-bit, signed)
*
* scale1 = (6 + 6) * 9.81 / (2^8 - 1) = 0.4616
* scale2 = (16 + 16) * 9.81 / (2^8 - 1) = 1.2311
*/
#define STK8312_SCALE_AVAIL "0.4616 1.2311"
static const int stk8312_scale_table[][2] = {
{0, 461600}, {1, 231100}
};
#define STK8312_ACCEL_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 stk8312_channels[] = {
STK8312_ACCEL_CHANNEL(STK8312_REG_XOUT, X),
STK8312_ACCEL_CHANNEL(STK8312_REG_YOUT, Y),
STK8312_ACCEL_CHANNEL(STK8312_REG_ZOUT, Z),
};
struct stk8312_data {
struct i2c_client *client;
struct mutex lock;
int range;
u8 mode;
};
static IIO_CONST_ATTR(in_accel_scale_available, STK8312_SCALE_AVAIL);
static struct attribute *stk8312_attributes[] = {
&iio_const_attr_in_accel_scale_available.dev_attr.attr,
NULL,
};
static const struct attribute_group stk8312_attribute_group = {
.attrs = stk8312_attributes
};
static int stk8312_otp_init(struct stk8312_data *data)
{
int ret;
int count = 10;
struct i2c_client *client = data->client;
ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPADDR, 0x70);
if (ret < 0)
goto exit_err;
ret = i2c_smbus_write_byte_data(client, STK8312_REG_OTPCTRL, 0x02);
if (ret < 0)
goto exit_err;
do {
usleep_range(1000, 5000);
ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPCTRL);
if (ret < 0)
goto exit_err;
count--;
} while (!(ret & 0x80) && count > 0);
if (count == 0)
goto exit_err;
ret = i2c_smbus_read_byte_data(client, STK8312_REG_OTPDATA);
if (ret < 0)
goto exit_err;
ret = i2c_smbus_write_byte_data(data->client,
STK8312_REG_AFECTRL, ret);
if (ret < 0)
goto exit_err;
msleep(150);
return ret;
exit_err:
dev_err(&client->dev, "failed to initialize sensor\n");
return ret;
}
static int stk8312_set_mode(struct stk8312_data *data, u8 mode)
{
int ret;
u8 masked_reg;
struct i2c_client *client = data->client;
if (mode > 1)
return -EINVAL;
else if (mode == data->mode)
return 0;
ret = i2c_smbus_read_byte_data(client, STK8312_REG_MODE);
if (ret < 0) {
dev_err(&client->dev, "failed to change sensor mode\n");
return ret;
}
masked_reg = ret & (~STK8312_MODE_MASK);
masked_reg |= mode;
ret = i2c_smbus_write_byte_data(client,
STK8312_REG_MODE, masked_reg);
if (ret < 0) {
dev_err(&client->dev, "failed to change sensor mode\n");
return ret;
}
data->mode = mode;
if (mode == STK8312_MODE_ACTIVE) {
/* Need to run OTP sequence before entering active mode */
usleep_range(1000, 5000);
ret = stk8312_otp_init(data);
}
return ret;
}
static int stk8312_set_range(struct stk8312_data *data, u8 range)
{
int ret;
u8 masked_reg;
u8 mode;
struct i2c_client *client = data->client;
if (range != 1 && range != 2)
return -EINVAL;
else if (range == data->range)
return 0;
mode = data->mode;
/* We need to go in standby mode to modify registers */
ret = stk8312_set_mode(data, STK8312_MODE_STANDBY);
if (ret < 0)
return ret;
ret = i2c_smbus_read_byte_data(client, STK8312_REG_STH);
if (ret < 0) {
dev_err(&client->dev, "failed to change sensor range\n");
return ret;
}
masked_reg = ret & (~STK8312_RNG_MASK);
masked_reg |= range << STK8312_RNG_SHIFT;
ret = i2c_smbus_write_byte_data(client, STK8312_REG_STH, masked_reg);
if (ret < 0)
dev_err(&client->dev, "failed to change sensor range\n");
else
data->range = range;
return stk8312_set_mode(data, mode);
}
static int stk8312_read_accel(struct stk8312_data *data, u8 address)
{
int ret;
struct i2c_client *client = data->client;
if (address > 2)
return -EINVAL;
ret = i2c_smbus_read_byte_data(client, address);
if (ret < 0) {
dev_err(&client->dev, "register read failed\n");
return ret;
}
return sign_extend32(ret, 7);
}
static int stk8312_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct stk8312_data *data = iio_priv(indio_dev);
if (chan->type != IIO_ACCEL)
return -EINVAL;
switch (mask) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&data->lock);
*val = stk8312_read_accel(data, chan->address);
mutex_unlock(&data->lock);
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
*val = stk8312_scale_table[data->range - 1][0];
*val2 = stk8312_scale_table[data->range - 1][1];
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int stk8312_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
int i;
int index = -1;
int ret;
struct stk8312_data *data = iio_priv(indio_dev);
switch (mask) {
case IIO_CHAN_INFO_SCALE:
for (i = 0; i < ARRAY_SIZE(stk8312_scale_table); i++)
if (val == stk8312_scale_table[i][0] &&
val2 == stk8312_scale_table[i][1]) {
index = i + 1;
break;
}
if (index < 0)
return -EINVAL;
mutex_lock(&data->lock);
ret = stk8312_set_range(data, index);
mutex_unlock(&data->lock);
return ret;
}
return -EINVAL;
}
static const struct iio_info stk8312_info = {
.driver_module = THIS_MODULE,
.read_raw = stk8312_read_raw,
.write_raw = stk8312_write_raw,
.attrs = &stk8312_attribute_group,
};
static int stk8312_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int ret;
struct iio_dev *indio_dev;
struct stk8312_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);
indio_dev->dev.parent = &client->dev;
indio_dev->info = &stk8312_info;
indio_dev->name = STK8312_DRIVER_NAME;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = stk8312_channels;
indio_dev->num_channels = ARRAY_SIZE(stk8312_channels);
/* A software reset is recommended at power-on */
ret = i2c_smbus_write_byte_data(data->client, STK8312_REG_RESET, 0x00);
if (ret < 0) {
dev_err(&client->dev, "failed to reset sensor\n");
return ret;
}
ret = stk8312_set_range(data, 1);
if (ret < 0)
return ret;
ret = stk8312_set_mode(data, STK8312_MODE_ACTIVE);
if (ret < 0)
return ret;
ret = iio_device_register(indio_dev);
if (ret < 0) {
dev_err(&client->dev, "device_register failed\n");
stk8312_set_mode(data, STK8312_MODE_STANDBY);
}
return ret;
}
static int stk8312_remove(struct i2c_client *client)
{
struct iio_dev *indio_dev = i2c_get_clientdata(client);
iio_device_unregister(indio_dev);
return stk8312_set_mode(iio_priv(indio_dev), STK8312_MODE_STANDBY);
}
#ifdef CONFIG_PM_SLEEP
static int stk8312_suspend(struct device *dev)
{
struct stk8312_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return stk8312_set_mode(data, STK8312_MODE_STANDBY);
}
static int stk8312_resume(struct device *dev)
{
struct stk8312_data *data;
data = iio_priv(i2c_get_clientdata(to_i2c_client(dev)));
return stk8312_set_mode(data, STK8312_MODE_ACTIVE);
}
static SIMPLE_DEV_PM_OPS(stk8312_pm_ops, stk8312_suspend, stk8312_resume);
#define STK8312_PM_OPS (&stk8312_pm_ops)
#else
#define STK8312_PM_OPS NULL
#endif
static const struct i2c_device_id stk8312_i2c_id[] = {
{"STK8312", 0},
{}
};
static const struct acpi_device_id stk8312_acpi_id[] = {
{"STK8312", 0},
{}
};
MODULE_DEVICE_TABLE(acpi, stk8312_acpi_id);
static struct i2c_driver stk8312_driver = {
.driver = {
.name = "stk8312",
.pm = STK8312_PM_OPS,
.acpi_match_table = ACPI_PTR(stk8312_acpi_id),
},
.probe = stk8312_probe,
.remove = stk8312_remove,
.id_table = stk8312_i2c_id,
};
module_i2c_driver(stk8312_driver);
MODULE_AUTHOR("Tiberiu Breana <tiberiu.a.breana@intel.com>");
MODULE_DESCRIPTION("STK8312 3-Axis Accelerometer driver");
MODULE_LICENSE("GPL v2");
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