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