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/*
* t5403.c - Support for EPCOS T5403 pressure/temperature sensor
*
* Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>
*
* 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.
*
* (7-bit I2C slave address 0x77)
*
* TODO: end-of-conversion irq
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/delay.h>
#define T5403_DATA 0xf5 /* data, LSB first, 16 bit */
#define T5403_CALIB_DATA 0x8e /* 10 calibration coeff., LSB first, 16 bit */
#define T5403_SLAVE_ADDR 0x88 /* I2C slave address, 0x77 */
#define T5403_COMMAND 0xf1
/* command bits */
#define T5403_MODE_SHIFT 3 /* conversion time: 2, 8, 16, 66 ms */
#define T5403_PT BIT(1) /* 0 .. pressure, 1 .. temperature measurement */
#define T5403_SCO BIT(0) /* start conversion */
#define T5403_MODE_LOW 0
#define T5403_MODE_STANDARD 1
#define T5403_MODE_HIGH 2
#define T5403_MODE_ULTRA_HIGH 3
#define T5403_I2C_MASK (~BIT(7))
#define T5403_I2C_ADDR 0x77
static const int t5403_pressure_conv_ms[] = {2, 8, 16, 66};
struct t5403_data {
struct i2c_client *client;
struct mutex lock;
int mode;
__le16 c[10];
};
#define T5403_C_U16(i) le16_to_cpu(data->c[(i) - 1])
#define T5403_C(i) sign_extend32(T5403_C_U16(i), 15)
static int t5403_read(struct t5403_data *data, bool pressure)
{
int wait_time = 3; /* wakeup time in ms */
int ret = i2c_smbus_write_byte_data(data->client, T5403_COMMAND,
(pressure ? (data->mode << T5403_MODE_SHIFT) : T5403_PT) |
T5403_SCO);
if (ret < 0)
return ret;
wait_time += pressure ? t5403_pressure_conv_ms[data->mode] : 2;
msleep(wait_time);
return i2c_smbus_read_word_data(data->client, T5403_DATA);
}
static int t5403_comp_pressure(struct t5403_data *data, int *val, int *val2)
{
int ret;
s16 t_r;
u16 p_r;
s32 S, O, X;
mutex_lock(&data->lock);
ret = t5403_read(data, false);
if (ret < 0)
goto done;
t_r = ret;
ret = t5403_read(data, true);
if (ret < 0)
goto done;
p_r = ret;
/* see EPCOS application note */
S = T5403_C_U16(3) + (s32) T5403_C_U16(4) * t_r / 0x20000 +
T5403_C(5) * t_r / 0x8000 * t_r / 0x80000 +
T5403_C(9) * t_r / 0x8000 * t_r / 0x8000 * t_r / 0x10000;
O = T5403_C(6) * 0x4000 + T5403_C(7) * t_r / 8 +
T5403_C(8) * t_r / 0x8000 * t_r / 16 +
T5403_C(9) * t_r / 0x8000 * t_r / 0x10000 * t_r;
X = (S * p_r + O) / 0x4000;
X += ((X - 75000) * (X - 75000) / 0x10000 - 9537) *
T5403_C(10) / 0x10000;
*val = X / 1000;
*val2 = (X % 1000) * 1000;
done:
mutex_unlock(&data->lock);
return ret;
}
static int t5403_comp_temp(struct t5403_data *data, int *val)
{
int ret;
s16 t_r;
mutex_lock(&data->lock);
ret = t5403_read(data, false);
if (ret < 0)
goto done;
t_r = ret;
/* see EPCOS application note */
*val = ((s32) T5403_C_U16(1) * t_r / 0x100 +
(s32) T5403_C_U16(2) * 0x40) * 1000 / 0x10000;
done:
mutex_unlock(&data->lock);
return ret;
}
static int t5403_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct t5403_data *data = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_PROCESSED:
switch (chan->type) {
case IIO_PRESSURE:
ret = t5403_comp_pressure(data, val, val2);
if (ret < 0)
return ret;
return IIO_VAL_INT_PLUS_MICRO;
case IIO_TEMP:
ret = t5403_comp_temp(data, val);
if (ret < 0)
return ret;
return IIO_VAL_INT;
default:
return -EINVAL;
}
case IIO_CHAN_INFO_INT_TIME:
*val = 0;
*val2 = t5403_pressure_conv_ms[data->mode] * 1000;
return IIO_VAL_INT_PLUS_MICRO;
default:
return -EINVAL;
}
}
static int t5403_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val, int val2, long mask)
{
struct t5403_data *data = iio_priv(indio_dev);
int i;
switch (mask) {
case IIO_CHAN_INFO_INT_TIME:
if (val != 0)
return -EINVAL;
for (i = 0; i < ARRAY_SIZE(t5403_pressure_conv_ms); i++)
if (val2 == t5403_pressure_conv_ms[i] * 1000) {
mutex_lock(&data->lock);
data->mode = i;
mutex_unlock(&data->lock);
return 0;
}
return -EINVAL;
default:
return -EINVAL;
}
}
static const struct iio_chan_spec t5403_channels[] = {
{
.type = IIO_PRESSURE,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |
BIT(IIO_CHAN_INFO_INT_TIME),
},
{
.type = IIO_TEMP,
.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
},
};
static IIO_CONST_ATTR_INT_TIME_AVAIL("0.002 0.008 0.016 0.066");
static struct attribute *t5403_attributes[] = {
&iio_const_attr_integration_time_available.dev_attr.attr,
NULL
};
static const struct attribute_group t5403_attribute_group = {
.attrs = t5403_attributes,
};
static const struct iio_info t5403_info = {
.read_raw = &t5403_read_raw,
.write_raw = &t5403_write_raw,
.attrs = &t5403_attribute_group,
};
static int t5403_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct t5403_data *data;
struct iio_dev *indio_dev;
int ret;
if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
I2C_FUNC_SMBUS_I2C_BLOCK))
return -EOPNOTSUPP;
ret = i2c_smbus_read_byte_data(client, T5403_SLAVE_ADDR);
if (ret < 0)
return ret;
if ((ret & T5403_I2C_MASK) != T5403_I2C_ADDR)
return -ENODEV;
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (!indio_dev)
return -ENOMEM;
data = iio_priv(indio_dev);
data->client = client;
mutex_init(&data->lock);
i2c_set_clientdata(client, indio_dev);
indio_dev->info = &t5403_info;
indio_dev->name = id->name;
indio_dev->dev.parent = &client->dev;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = t5403_channels;
indio_dev->num_channels = ARRAY_SIZE(t5403_channels);
data->mode = T5403_MODE_STANDARD;
ret = i2c_smbus_read_i2c_block_data(data->client, T5403_CALIB_DATA,
sizeof(data->c), (u8 *) data->c);
if (ret < 0)
return ret;
return devm_iio_device_register(&client->dev, indio_dev);
}
static const struct i2c_device_id t5403_id[] = {
{ "t5403", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, t5403_id);
static struct i2c_driver t5403_driver = {
.driver = {
.name = "t5403",
},
.probe = t5403_probe,
.id_table = t5403_id,
};
module_i2c_driver(t5403_driver);
MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");
MODULE_DESCRIPTION("EPCOS T5403 pressure/temperature sensor driver");
MODULE_LICENSE("GPL");
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