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1// SPDX-License-Identifier: GPL-2.0+2/*3 * ens210.c - Support for ScioSense ens210 temperature & humidity sensor family4 *5 * (7-bit I2C slave address 0x43 ENS210)6 * (7-bit I2C slave address 0x43 ENS210A)7 * (7-bit I2C slave address 0x44 ENS211)8 * (7-bit I2C slave address 0x45 ENS212)9 * (7-bit I2C slave address 0x46 ENS213A)10 * (7-bit I2C slave address 0x47 ENS215)11 *12 * Datasheet:13 * https://www.sciosense.com/wp-content/uploads/2024/04/ENS21x-Datasheet.pdf14 * https://www.sciosense.com/wp-content/uploads/2023/12/ENS210-Datasheet.pdf15 */16 17#include <linux/crc7.h>18#include <linux/delay.h>19#include <linux/i2c.h>20#include <linux/iio/iio.h>21#include <linux/mod_devicetable.h>22#include <linux/module.h>23#include <linux/types.h>24 25#include <linux/unaligned.h>26 27/* register definitions */28#define ENS210_REG_PART_ID 0x0029#define ENS210_REG_DIE_REV 0x0230#define ENS210_REG_UID 0x0431#define ENS210_REG_SYS_CTRL 0x1032#define ENS210_REG_SYS_STAT 0x1133#define ENS210_REG_SENS_RUN 0x2134#define ENS210_REG_SENS_START 0x2235#define ENS210_REG_SENS_STOP 0x2336#define ENS210_REG_SENS_STAT 0x2437#define ENS210_REG_T_VAL 0x3038#define ENS210_REG_H_VAL 0x3339 40/* value definitions */41#define ENS210_SENS_START_T_START BIT(0)42#define ENS210_SENS_START_H_START BIT(1)43 44#define ENS210_SENS_STAT_T_ACTIVE BIT(0)45#define ENS210_SENS_STAT_H_ACTIVE BIT(1)46 47#define ENS210_SYS_CTRL_LOW_POWER_ENABLE BIT(0)48#define ENS210_SYS_CTRL_SYS_RESET BIT(7)49 50#define ENS210_SYS_STAT_SYS_ACTIVE BIT(0)51 52enum ens210_partnumber {53 ENS210 = 0x0210,54 ENS210A = 0xa210,55 ENS211 = 0x0211,56 ENS212 = 0x0212,57 ENS213A = 0xa213,58 ENS215 = 0x0215,59};60 61/**62 * struct ens210_chip_info - Humidity/Temperature chip specific information63 * @name: name of device64 * @part_id: chip identifier65 * @conv_time_msec: time for conversion calculation in m/s66 */67struct ens210_chip_info {68 const char *name;69 enum ens210_partnumber part_id;70 unsigned int conv_time_msec;71};72 73/**74 * struct ens210_data - Humidity/Temperature sensor device structure75 * @client: i2c client76 * @chip_info: chip specific information77 * @lock: lock protecting against simultaneous callers of get_measurement78 * since multiple uninterrupted transactions are required79 */80struct ens210_data {81 struct i2c_client *client;82 const struct ens210_chip_info *chip_info;83 struct mutex lock;84};85 86/* calculate 17-bit crc7 */87static u8 ens210_crc7(u32 val)88{89 unsigned int val_be = (val & 0x1ffff) >> 0x8;90 91 return crc7_be(0xde, (u8 *)&val_be, 3) >> 1;92}93 94static int ens210_get_measurement(struct iio_dev *indio_dev, bool temp, int *val)95{96 struct ens210_data *data = iio_priv(indio_dev);97 struct device *dev = &data->client->dev;98 u32 regval;99 u8 regval_le[3];100 int ret;101 102 /* assert read */103 ret = i2c_smbus_write_byte_data(data->client, ENS210_REG_SENS_START,104 temp ? ENS210_SENS_START_T_START :105 ENS210_SENS_START_H_START);106 if (ret)107 return ret;108 109 /* wait for conversion to be ready */110 msleep(data->chip_info->conv_time_msec);111 112 ret = i2c_smbus_read_byte_data(data->client, ENS210_REG_SENS_STAT);113 if (ret < 0)114 return ret;115 116 /* perform read */117 ret = i2c_smbus_read_i2c_block_data(118 data->client, temp ? ENS210_REG_T_VAL : ENS210_REG_H_VAL, 3,119 regval_le);120 if (ret < 0) {121 dev_err(dev, "failed to read register");122 return -EIO;123 }124 if (ret != 3) {125 dev_err(dev, "expected 3 bytes, received %d\n", ret);126 return -EIO;127 }128 129 regval = get_unaligned_le24(regval_le);130 if (ens210_crc7(regval) != ((regval >> 17) & 0x7f)) {131 dev_err(dev, "invalid crc\n");132 return -EIO;133 }134 135 if (!((regval >> 16) & 0x1)) {136 dev_err(dev, "data is not valid");137 return -EIO;138 }139 140 *val = regval & GENMASK(15, 0);141 return IIO_VAL_INT;142}143 144static int ens210_read_raw(struct iio_dev *indio_dev,145 struct iio_chan_spec const *channel, int *val,146 int *val2, long mask)147{148 struct ens210_data *data = iio_priv(indio_dev);149 int ret;150 151 switch (mask) {152 case IIO_CHAN_INFO_RAW:153 scoped_guard(mutex, &data->lock) {154 ret = ens210_get_measurement(155 indio_dev, channel->type == IIO_TEMP, val);156 if (ret)157 return ret;158 return IIO_VAL_INT;159 }160 return -EINVAL; /* compiler warning workaround */161 case IIO_CHAN_INFO_SCALE:162 if (channel->type == IIO_TEMP) {163 *val = 15;164 *val2 = 625000;165 } else {166 *val = 1;167 *val2 = 953125;168 }169 return IIO_VAL_INT_PLUS_MICRO;170 case IIO_CHAN_INFO_OFFSET:171 *val = -17481;172 *val2 = 600000;173 return IIO_VAL_INT_PLUS_MICRO;174 default:175 return -EINVAL;176 }177}178 179static const struct iio_chan_spec ens210_channels[] = {180 {181 .type = IIO_TEMP,182 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |183 BIT(IIO_CHAN_INFO_SCALE) |184 BIT(IIO_CHAN_INFO_OFFSET),185 },186 {187 .type = IIO_HUMIDITYRELATIVE,188 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |189 BIT(IIO_CHAN_INFO_SCALE),190 }191};192 193static const struct iio_info ens210_info = {194 .read_raw = ens210_read_raw,195};196 197static int ens210_probe(struct i2c_client *client)198{199 struct ens210_data *data;200 struct iio_dev *indio_dev;201 uint16_t part_id;202 int ret;203 204 if (!i2c_check_functionality(client->adapter,205 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |206 I2C_FUNC_SMBUS_WRITE_BYTE |207 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {208 return dev_err_probe(&client->dev, -EOPNOTSUPP,209 "adapter does not support some i2c transactions\n");210 }211 212 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));213 if (!indio_dev)214 return -ENOMEM;215 216 data = iio_priv(indio_dev);217 data->client = client;218 mutex_init(&data->lock);219 data->chip_info = i2c_get_match_data(client);220 221 ret = devm_regulator_get_enable(&client->dev, "vdd");222 if (ret)223 return ret;224 225 /* reset device */226 ret = i2c_smbus_write_byte_data(client, ENS210_REG_SYS_CTRL,227 ENS210_SYS_CTRL_SYS_RESET);228 if (ret)229 return ret;230 231 /* wait for device to become active */232 usleep_range(4000, 5000);233 234 /* disable low power mode */235 ret = i2c_smbus_write_byte_data(client, ENS210_REG_SYS_CTRL, 0x00);236 if (ret)237 return ret;238 239 /* wait for device to finish */240 usleep_range(4000, 5000);241 242 /* get part_id */243 ret = i2c_smbus_read_word_data(client, ENS210_REG_PART_ID);244 if (ret < 0)245 return ret;246 part_id = ret;247 248 if (part_id != data->chip_info->part_id) {249 dev_info(&client->dev,250 "Part ID does not match (0x%04x != 0x%04x)\n", part_id,251 data->chip_info->part_id);252 }253 254 /* reenable low power */255 ret = i2c_smbus_write_byte_data(client, ENS210_REG_SYS_CTRL,256 ENS210_SYS_CTRL_LOW_POWER_ENABLE);257 if (ret)258 return ret;259 260 indio_dev->name = data->chip_info->name;261 indio_dev->modes = INDIO_DIRECT_MODE;262 indio_dev->channels = ens210_channels;263 indio_dev->num_channels = ARRAY_SIZE(ens210_channels);264 indio_dev->info = &ens210_info;265 266 return devm_iio_device_register(&client->dev, indio_dev);267}268 269static const struct ens210_chip_info ens210_chip_info_data = {270 .name = "ens210",271 .part_id = ENS210,272 .conv_time_msec = 130,273};274 275static const struct ens210_chip_info ens210a_chip_info_data = {276 .name = "ens210a",277 .part_id = ENS210A,278 .conv_time_msec = 130,279};280 281static const struct ens210_chip_info ens211_chip_info_data = {282 .name = "ens211",283 .part_id = ENS211,284 .conv_time_msec = 32,285};286 287static const struct ens210_chip_info ens212_chip_info_data = {288 .name = "ens212",289 .part_id = ENS212,290 .conv_time_msec = 32,291};292 293static const struct ens210_chip_info ens213a_chip_info_data = {294 .name = "ens213a",295 .part_id = ENS213A,296 .conv_time_msec = 130,297};298 299static const struct ens210_chip_info ens215_chip_info_data = {300 .name = "ens215",301 .part_id = ENS215,302 .conv_time_msec = 130,303};304 305static const struct of_device_id ens210_of_match[] = {306 { .compatible = "sciosense,ens210", .data = &ens210_chip_info_data },307 { .compatible = "sciosense,ens210a", .data = &ens210a_chip_info_data },308 { .compatible = "sciosense,ens211", .data = &ens211_chip_info_data },309 { .compatible = "sciosense,ens212", .data = &ens212_chip_info_data },310 { .compatible = "sciosense,ens213a", .data = &ens213a_chip_info_data },311 { .compatible = "sciosense,ens215", .data = &ens215_chip_info_data },312 { }313};314MODULE_DEVICE_TABLE(of, ens210_of_match);315 316static const struct i2c_device_id ens210_id_table[] = {317 { "ens210", (kernel_ulong_t)&ens210_chip_info_data },318 { "ens210a", (kernel_ulong_t)&ens210a_chip_info_data },319 { "ens211", (kernel_ulong_t)&ens211_chip_info_data },320 { "ens212", (kernel_ulong_t)&ens212_chip_info_data },321 { "ens213a", (kernel_ulong_t)&ens213a_chip_info_data },322 { "ens215", (kernel_ulong_t)&ens215_chip_info_data },323 { }324};325MODULE_DEVICE_TABLE(i2c, ens210_id_table);326 327static struct i2c_driver ens210_driver = {328 .probe = ens210_probe,329 .id_table = ens210_id_table,330 .driver = {331 .name = "ens210",332 .of_match_table = ens210_of_match,333 },334};335module_i2c_driver(ens210_driver);336 337MODULE_DESCRIPTION("ScioSense ENS210 temperature and humidity sensor driver");338MODULE_AUTHOR("Joshua Felmeden <jfelmeden@thegoodpenguin.co.uk>");339MODULE_LICENSE("GPL");340