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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * tsys01.c - Support for Measurement-Specialties tsys01 temperature sensor4 *5 * Copyright (c) 2015 Measurement-Specialties6 *7 * Datasheet:8 * http://www.meas-spec.com/downloads/TSYS01_Digital_Temperature_Sensor.pdf9 */10 11#include <linux/iio/iio.h>12#include <linux/iio/sysfs.h>13#include <linux/device.h>14#include <linux/mutex.h>15#include <linux/module.h>16#include <linux/mod_devicetable.h>17#include <linux/init.h>18#include <linux/kernel.h>19#include <linux/stat.h>20#include "../common/ms_sensors/ms_sensors_i2c.h"21 22/* TSYS01 Commands */23#define TSYS01_RESET 0x1E24#define TSYS01_CONVERSION_START 0x4825#define TSYS01_ADC_READ 0x0026#define TSYS01_PROM_READ 0xA027 28#define TSYS01_PROM_WORDS_NB 829 30struct tsys01_dev {31 void *client;32 struct mutex lock; /* lock during conversion */33 34 int (*reset)(void *cli, u8 cmd, unsigned int delay);35 int (*convert_and_read)(void *cli, u8 conv, u8 rd,36 unsigned int delay, u32 *adc);37 int (*read_prom_word)(void *cli, int cmd, u16 *word);38 39 u16 prom[TSYS01_PROM_WORDS_NB];40};41 42/* Multiplication coefficients for temperature computation */43static const int coeff_mul[] = { -1500000, 1000000, -2000000,44 4000000, -2000000 };45 46static int tsys01_read_temperature(struct iio_dev *indio_dev,47 s32 *temperature)48{49 int ret, i;50 u32 adc;51 s64 temp = 0;52 struct tsys01_dev *dev_data = iio_priv(indio_dev);53 54 mutex_lock(&dev_data->lock);55 ret = dev_data->convert_and_read(dev_data->client,56 TSYS01_CONVERSION_START,57 TSYS01_ADC_READ, 9000, &adc);58 mutex_unlock(&dev_data->lock);59 if (ret)60 return ret;61 62 adc >>= 8;63 64 /* Temperature algorithm */65 for (i = 4; i > 0; i--) {66 temp += coeff_mul[i] *67 (s64)dev_data->prom[5 - i];68 temp *= (s64)adc;69 temp = div64_s64(temp, 100000);70 }71 temp *= 10;72 temp += coeff_mul[0] * (s64)dev_data->prom[5];73 temp = div64_s64(temp, 100000);74 75 *temperature = temp;76 77 return 0;78}79 80static int tsys01_read_raw(struct iio_dev *indio_dev,81 struct iio_chan_spec const *channel, int *val,82 int *val2, long mask)83{84 int ret;85 s32 temperature;86 87 switch (mask) {88 case IIO_CHAN_INFO_PROCESSED:89 switch (channel->type) {90 case IIO_TEMP: /* in milli °C */91 ret = tsys01_read_temperature(indio_dev, &temperature);92 if (ret)93 return ret;94 *val = temperature;95 96 return IIO_VAL_INT;97 default:98 return -EINVAL;99 }100 default:101 return -EINVAL;102 }103}104 105static const struct iio_chan_spec tsys01_channels[] = {106 {107 .type = IIO_TEMP,108 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),109 }110};111 112static const struct iio_info tsys01_info = {113 .read_raw = tsys01_read_raw,114};115 116static bool tsys01_crc_valid(u16 *n_prom)117{118 u8 cnt;119 u8 sum = 0;120 121 for (cnt = 0; cnt < TSYS01_PROM_WORDS_NB; cnt++)122 sum += ((n_prom[0] >> 8) + (n_prom[0] & 0xFF));123 124 return (sum == 0);125}126 127static int tsys01_read_prom(struct iio_dev *indio_dev)128{129 int i, ret;130 struct tsys01_dev *dev_data = iio_priv(indio_dev);131 char buf[7 * TSYS01_PROM_WORDS_NB + 1];132 char *ptr = buf;133 134 for (i = 0; i < TSYS01_PROM_WORDS_NB; i++) {135 ret = dev_data->read_prom_word(dev_data->client,136 TSYS01_PROM_READ + (i << 1),137 &dev_data->prom[i]);138 if (ret)139 return ret;140 141 ret = sprintf(ptr, "0x%04x ", dev_data->prom[i]);142 ptr += ret;143 }144 145 if (!tsys01_crc_valid(dev_data->prom)) {146 dev_err(&indio_dev->dev, "prom crc check error\n");147 return -ENODEV;148 }149 *ptr = 0;150 dev_info(&indio_dev->dev, "PROM coefficients : %s\n", buf);151 152 return 0;153}154 155static int tsys01_probe(struct iio_dev *indio_dev, struct device *dev)156{157 int ret;158 struct tsys01_dev *dev_data = iio_priv(indio_dev);159 160 mutex_init(&dev_data->lock);161 162 indio_dev->info = &tsys01_info;163 indio_dev->name = dev->driver->name;164 indio_dev->modes = INDIO_DIRECT_MODE;165 indio_dev->channels = tsys01_channels;166 indio_dev->num_channels = ARRAY_SIZE(tsys01_channels);167 168 ret = dev_data->reset(dev_data->client, TSYS01_RESET, 3000);169 if (ret)170 return ret;171 172 ret = tsys01_read_prom(indio_dev);173 if (ret)174 return ret;175 176 return devm_iio_device_register(dev, indio_dev);177}178 179static int tsys01_i2c_probe(struct i2c_client *client)180{181 struct tsys01_dev *dev_data;182 struct iio_dev *indio_dev;183 184 if (!i2c_check_functionality(client->adapter,185 I2C_FUNC_SMBUS_WORD_DATA |186 I2C_FUNC_SMBUS_WRITE_BYTE |187 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {188 dev_err(&client->dev,189 "Adapter does not support some i2c transaction\n");190 return -EOPNOTSUPP;191 }192 193 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));194 if (!indio_dev)195 return -ENOMEM;196 197 dev_data = iio_priv(indio_dev);198 dev_data->client = client;199 dev_data->reset = ms_sensors_reset;200 dev_data->read_prom_word = ms_sensors_read_prom_word;201 dev_data->convert_and_read = ms_sensors_convert_and_read;202 203 i2c_set_clientdata(client, indio_dev);204 205 return tsys01_probe(indio_dev, &client->dev);206}207 208static const struct i2c_device_id tsys01_id[] = {209 { "tsys01" },210 {}211};212MODULE_DEVICE_TABLE(i2c, tsys01_id);213 214static const struct of_device_id tsys01_of_match[] = {215 { .compatible = "meas,tsys01", },216 { },217};218MODULE_DEVICE_TABLE(of, tsys01_of_match);219 220static struct i2c_driver tsys01_driver = {221 .probe = tsys01_i2c_probe,222 .id_table = tsys01_id,223 .driver = {224 .name = "tsys01",225 .of_match_table = tsys01_of_match,226 },227};228 229module_i2c_driver(tsys01_driver);230 231MODULE_DESCRIPTION("Measurement-Specialties tsys01 temperature driver");232MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");233MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");234MODULE_LICENSE("GPL v2");235MODULE_IMPORT_NS(IIO_MEAS_SPEC_SENSORS);236