271 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * t5403.c - Support for EPCOS T5403 pressure/temperature sensor4 *5 * Copyright (c) 2014 Peter Meerwald <pmeerw@pmeerw.net>6 *7 * (7-bit I2C slave address 0x77)8 *9 * TODO: end-of-conversion irq10 */11 12#include <linux/module.h>13#include <linux/i2c.h>14#include <linux/iio/iio.h>15#include <linux/iio/sysfs.h>16#include <linux/delay.h>17 18#define T5403_DATA 0xf5 /* data, LSB first, 16 bit */19#define T5403_CALIB_DATA 0x8e /* 10 calibration coeff., LSB first, 16 bit */20#define T5403_SLAVE_ADDR 0x88 /* I2C slave address, 0x77 */21#define T5403_COMMAND 0xf122 23/* command bits */24#define T5403_MODE_SHIFT 3 /* conversion time: 2, 8, 16, 66 ms */25#define T5403_PT BIT(1) /* 0 .. pressure, 1 .. temperature measurement */26#define T5403_SCO BIT(0) /* start conversion */27 28#define T5403_MODE_LOW 029#define T5403_MODE_STANDARD 130#define T5403_MODE_HIGH 231#define T5403_MODE_ULTRA_HIGH 332 33#define T5403_I2C_MASK (~BIT(7))34#define T5403_I2C_ADDR 0x7735 36static const int t5403_pressure_conv_ms[] = {2, 8, 16, 66};37 38struct t5403_data {39 struct i2c_client *client;40 struct mutex lock;41 int mode;42 __le16 c[10];43};44 45#define T5403_C_U16(i) le16_to_cpu(data->c[(i) - 1])46#define T5403_C(i) sign_extend32(T5403_C_U16(i), 15)47 48static int t5403_read(struct t5403_data *data, bool pressure)49{50 int wait_time = 3; /* wakeup time in ms */51 52 int ret = i2c_smbus_write_byte_data(data->client, T5403_COMMAND,53 (pressure ? (data->mode << T5403_MODE_SHIFT) : T5403_PT) |54 T5403_SCO);55 if (ret < 0)56 return ret;57 58 wait_time += pressure ? t5403_pressure_conv_ms[data->mode] : 2;59 60 msleep(wait_time);61 62 return i2c_smbus_read_word_data(data->client, T5403_DATA);63}64 65static int t5403_comp_pressure(struct t5403_data *data, int *val, int *val2)66{67 int ret;68 s16 t_r;69 u16 p_r;70 s32 S, O, X;71 72 mutex_lock(&data->lock);73 74 ret = t5403_read(data, false);75 if (ret < 0)76 goto done;77 t_r = ret;78 79 ret = t5403_read(data, true);80 if (ret < 0)81 goto done;82 p_r = ret;83 84 /* see EPCOS application note */85 S = T5403_C_U16(3) + (s32) T5403_C_U16(4) * t_r / 0x20000 +86 T5403_C(5) * t_r / 0x8000 * t_r / 0x80000 +87 T5403_C(9) * t_r / 0x8000 * t_r / 0x8000 * t_r / 0x10000;88 89 O = T5403_C(6) * 0x4000 + T5403_C(7) * t_r / 8 +90 T5403_C(8) * t_r / 0x8000 * t_r / 16 +91 T5403_C(9) * t_r / 0x8000 * t_r / 0x10000 * t_r;92 93 X = (S * p_r + O) / 0x4000;94 95 X += ((X - 75000) * (X - 75000) / 0x10000 - 9537) *96 T5403_C(10) / 0x10000;97 98 *val = X / 1000;99 *val2 = (X % 1000) * 1000;100 101done:102 mutex_unlock(&data->lock);103 return ret;104}105 106static int t5403_comp_temp(struct t5403_data *data, int *val)107{108 int ret;109 s16 t_r;110 111 mutex_lock(&data->lock);112 ret = t5403_read(data, false);113 if (ret < 0)114 goto done;115 t_r = ret;116 117 /* see EPCOS application note */118 *val = ((s32) T5403_C_U16(1) * t_r / 0x100 +119 (s32) T5403_C_U16(2) * 0x40) * 1000 / 0x10000;120 121done:122 mutex_unlock(&data->lock);123 return ret;124}125 126static int t5403_read_raw(struct iio_dev *indio_dev,127 struct iio_chan_spec const *chan,128 int *val, int *val2, long mask)129{130 struct t5403_data *data = iio_priv(indio_dev);131 int ret;132 133 switch (mask) {134 case IIO_CHAN_INFO_PROCESSED:135 switch (chan->type) {136 case IIO_PRESSURE:137 ret = t5403_comp_pressure(data, val, val2);138 if (ret < 0)139 return ret;140 return IIO_VAL_INT_PLUS_MICRO;141 case IIO_TEMP:142 ret = t5403_comp_temp(data, val);143 if (ret < 0)144 return ret;145 return IIO_VAL_INT;146 default:147 return -EINVAL;148 }149 case IIO_CHAN_INFO_INT_TIME:150 *val = 0;151 *val2 = t5403_pressure_conv_ms[data->mode] * 1000;152 return IIO_VAL_INT_PLUS_MICRO;153 default:154 return -EINVAL;155 }156}157 158static int t5403_write_raw(struct iio_dev *indio_dev,159 struct iio_chan_spec const *chan,160 int val, int val2, long mask)161{162 struct t5403_data *data = iio_priv(indio_dev);163 int i;164 165 switch (mask) {166 case IIO_CHAN_INFO_INT_TIME:167 if (val != 0)168 return -EINVAL;169 for (i = 0; i < ARRAY_SIZE(t5403_pressure_conv_ms); i++)170 if (val2 == t5403_pressure_conv_ms[i] * 1000) {171 mutex_lock(&data->lock);172 data->mode = i;173 mutex_unlock(&data->lock);174 return 0;175 }176 return -EINVAL;177 default:178 return -EINVAL;179 }180}181 182static const struct iio_chan_spec t5403_channels[] = {183 {184 .type = IIO_PRESSURE,185 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) |186 BIT(IIO_CHAN_INFO_INT_TIME),187 },188 {189 .type = IIO_TEMP,190 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),191 },192};193 194static IIO_CONST_ATTR_INT_TIME_AVAIL("0.002 0.008 0.016 0.066");195 196static struct attribute *t5403_attributes[] = {197 &iio_const_attr_integration_time_available.dev_attr.attr,198 NULL199};200 201static const struct attribute_group t5403_attribute_group = {202 .attrs = t5403_attributes,203};204 205static const struct iio_info t5403_info = {206 .read_raw = &t5403_read_raw,207 .write_raw = &t5403_write_raw,208 .attrs = &t5403_attribute_group,209};210 211static int t5403_probe(struct i2c_client *client)212{213 const struct i2c_device_id *id = i2c_client_get_device_id(client);214 struct t5403_data *data;215 struct iio_dev *indio_dev;216 int ret;217 218 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |219 I2C_FUNC_SMBUS_I2C_BLOCK))220 return -EOPNOTSUPP;221 222 ret = i2c_smbus_read_byte_data(client, T5403_SLAVE_ADDR);223 if (ret < 0)224 return ret;225 if ((ret & T5403_I2C_MASK) != T5403_I2C_ADDR)226 return -ENODEV;227 228 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));229 if (!indio_dev)230 return -ENOMEM;231 232 data = iio_priv(indio_dev);233 data->client = client;234 mutex_init(&data->lock);235 236 i2c_set_clientdata(client, indio_dev);237 indio_dev->info = &t5403_info;238 indio_dev->name = id->name;239 indio_dev->modes = INDIO_DIRECT_MODE;240 indio_dev->channels = t5403_channels;241 indio_dev->num_channels = ARRAY_SIZE(t5403_channels);242 243 data->mode = T5403_MODE_STANDARD;244 245 ret = i2c_smbus_read_i2c_block_data(data->client, T5403_CALIB_DATA,246 sizeof(data->c), (u8 *) data->c);247 if (ret < 0)248 return ret;249 250 return devm_iio_device_register(&client->dev, indio_dev);251}252 253static const struct i2c_device_id t5403_id[] = {254 { "t5403" },255 { }256};257MODULE_DEVICE_TABLE(i2c, t5403_id);258 259static struct i2c_driver t5403_driver = {260 .driver = {261 .name = "t5403",262 },263 .probe = t5403_probe,264 .id_table = t5403_id,265};266module_i2c_driver(t5403_driver);267 268MODULE_AUTHOR("Peter Meerwald <pmeerw@pmeerw.net>");269MODULE_DESCRIPTION("EPCOS T5403 pressure/temperature sensor driver");270MODULE_LICENSE("GPL");271