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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * This is a non-complete driver implementation for the4 * HS3001 humidity and temperature sensor and compatibles. It does not include5 * the configuration possibilities, where it needs to be set to 'programming mode'6 * during power-up.7 *8 *9 * Copyright (C) 2023 SYS TEC electronic AG10 * Author: Andre Werner <andre.werner@systec-electronic.com>11 */12 13#include <linux/bitfield.h>14#include <linux/delay.h>15#include <linux/err.h>16#include <linux/hwmon.h>17#include <linux/i2c.h>18#include <linux/init.h>19#include <linux/kernel.h>20#include <linux/module.h>21#include <linux/of_device.h>22#include <linux/slab.h>23#include <linux/types.h>24 25/* Measurement times */26#define HS3001_WAKEUP_TIME 100 /* us */27#define HS3001_8BIT_RESOLUTION 550 /* us */28#define HS3001_10BIT_RESOLUTION 1310 /* us */29#define HS3001_12BIT_RESOLUTION 4500 /* us */30#define HS3001_14BIT_RESOLUTION 16900 /* us */31 32#define HS3001_RESPONSE_LENGTH 433 34#define HS3001_FIXPOINT_ARITH 1000U35 36#define HS3001_MASK_HUMIDITY_0X3FFF GENMASK(13, 0)37#define HS3001_MASK_STATUS_0XC0 GENMASK(7, 6)38 39/* Definitions for Status Bits of A/D Data */40#define HS3001_DATA_VALID 0x00 /* Valid Data */41#define HS3001_DATA_STALE 0x01 /* Stale Data */42 43struct hs3001_data {44 struct i2c_client *client;45 struct mutex i2c_lock; /* lock for sending i2c commands */46 u32 wait_time; /* in us */47 int temperature; /* in milli degree */48 u32 humidity; /* in milli % */49};50 51static int hs3001_extract_temperature(u16 raw)52{53 /* fixpoint arithmetic 1 digit */54 u32 temp = (raw >> 2) * HS3001_FIXPOINT_ARITH * 165;55 56 temp /= (1 << 14) - 1;57 58 return (int)temp - 40 * HS3001_FIXPOINT_ARITH;59}60 61static u32 hs3001_extract_humidity(u16 raw)62{63 u32 hum = (raw & HS3001_MASK_HUMIDITY_0X3FFF) * HS3001_FIXPOINT_ARITH * 100;64 65 return hum / (1 << 14) - 1;66}67 68static int hs3001_data_fetch_command(struct i2c_client *client,69 struct hs3001_data *data)70{71 int ret;72 u8 buf[HS3001_RESPONSE_LENGTH];73 u8 hs3001_status;74 75 ret = i2c_master_recv(client, buf, HS3001_RESPONSE_LENGTH);76 if (ret != HS3001_RESPONSE_LENGTH) {77 ret = ret < 0 ? ret : -EIO;78 dev_dbg(&client->dev,79 "Error in i2c communication. Error code: %d.\n", ret);80 return ret;81 }82 83 hs3001_status = FIELD_GET(HS3001_MASK_STATUS_0XC0, buf[0]);84 if (hs3001_status == HS3001_DATA_STALE) {85 dev_dbg(&client->dev, "Sensor busy.\n");86 return -EBUSY;87 }88 if (hs3001_status != HS3001_DATA_VALID) {89 dev_dbg(&client->dev, "Data invalid.\n");90 return -EIO;91 }92 93 data->humidity =94 hs3001_extract_humidity(be16_to_cpup((__be16 *)&buf[0]));95 data->temperature =96 hs3001_extract_temperature(be16_to_cpup((__be16 *)&buf[2]));97 98 return 0;99}100 101static umode_t hs3001_is_visible(const void *data, enum hwmon_sensor_types type,102 u32 attr, int channel)103{104 /* Both, humidity and temperature can only be read. */105 return 0444;106}107 108static int hs3001_read(struct device *dev, enum hwmon_sensor_types type,109 u32 attr, int channel, long *val)110{111 struct hs3001_data *data = dev_get_drvdata(dev);112 struct i2c_client *client = data->client;113 int ret;114 115 mutex_lock(&data->i2c_lock);116 ret = i2c_master_send(client, NULL, 0);117 if (ret < 0) {118 mutex_unlock(&data->i2c_lock);119 return ret;120 }121 122 /*123 * Sensor needs some time to process measurement depending on124 * resolution (ref. datasheet)125 */126 fsleep(data->wait_time);127 128 ret = hs3001_data_fetch_command(client, data);129 mutex_unlock(&data->i2c_lock);130 131 if (ret < 0)132 return ret;133 134 switch (type) {135 case hwmon_temp:136 switch (attr) {137 case hwmon_temp_input:138 *val = data->temperature;139 break;140 default:141 return -EINVAL;142 }143 break;144 case hwmon_humidity:145 switch (attr) {146 case hwmon_humidity_input:147 *val = data->humidity;148 break;149 default:150 return -EINVAL;151 }152 break;153 default:154 return -EINVAL;155 }156 157 return 0;158}159 160static const struct hwmon_channel_info *hs3001_info[] = {161 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),162 HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT),163 NULL164};165 166static const struct hwmon_ops hs3001_hwmon_ops = {167 .is_visible = hs3001_is_visible,168 .read = hs3001_read,169};170 171static const struct hwmon_chip_info hs3001_chip_info = {172 .ops = &hs3001_hwmon_ops,173 .info = hs3001_info,174};175 176/* device ID table */177static const struct i2c_device_id hs3001_ids[] = {178 { "hs3001" },179 { },180};181 182MODULE_DEVICE_TABLE(i2c, hs3001_ids);183 184static const struct of_device_id hs3001_of_match[] = {185 {.compatible = "renesas,hs3001"},186 { },187};188 189MODULE_DEVICE_TABLE(of, hs3001_of_match);190 191static int hs3001_probe(struct i2c_client *client)192{193 struct hs3001_data *data;194 struct device *hwmon_dev;195 struct device *dev = &client->dev;196 197 if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C))198 return -EOPNOTSUPP;199 200 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);201 if (!data)202 return -ENOMEM;203 204 data->client = client;205 206 /*207 * Measurement time = wake-up time + measurement time temperature208 * + measurement time humidity. This is currently static, because209 * enabling programming mode is not supported, yet.210 */211 data->wait_time = (HS3001_WAKEUP_TIME + HS3001_14BIT_RESOLUTION +212 HS3001_14BIT_RESOLUTION);213 214 mutex_init(&data->i2c_lock);215 216 hwmon_dev = devm_hwmon_device_register_with_info(dev,217 client->name,218 data,219 &hs3001_chip_info,220 NULL);221 222 if (IS_ERR(hwmon_dev))223 return dev_err_probe(dev, PTR_ERR(hwmon_dev),224 "Unable to register hwmon device.\n");225 226 return 0;227}228 229static struct i2c_driver hs3001_i2c_driver = {230 .driver = {231 .name = "hs3001",232 .of_match_table = hs3001_of_match,233 },234 .probe = hs3001_probe,235 .id_table = hs3001_ids,236};237 238module_i2c_driver(hs3001_i2c_driver);239 240MODULE_AUTHOR("Andre Werner <andre.werner@systec-electronic.com>");241MODULE_DESCRIPTION("HS3001 humidity and temperature sensor base driver");242MODULE_LICENSE("GPL");243