1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * htu21.c - Support for Measurement-Specialties 4 * htu21 temperature & humidity sensor 5 * and humidity part of MS8607 sensor 6 * 7 * Copyright (c) 2014 Measurement-Specialties 8 * 9 * (7-bit I2C slave address 0x40) 10 * 11 * Datasheet: 12 * http://www.meas-spec.com/downloads/HTU21D.pdf 13 * Datasheet: 14 * http://www.meas-spec.com/downloads/MS8607-02BA01.pdf 15 */ 16 17 #include <linux/init.h> 18 #include <linux/device.h> 19 #include <linux/kernel.h> 20 #include <linux/stat.h> 21 #include <linux/module.h> 22 #include <linux/iio/iio.h> 23 #include <linux/iio/sysfs.h> 24 25 #include "../common/ms_sensors/ms_sensors_i2c.h" 26 27 #define HTU21_RESET 0xFE 28 29 enum { 30 HTU21, 31 MS8607 32 }; 33 34 static const int htu21_samp_freq[4] = { 20, 40, 70, 120 }; 35 /* String copy of the above const for readability purpose */ 36 static const char htu21_show_samp_freq[] = "20 40 70 120"; 37 38 static int htu21_read_raw(struct iio_dev *indio_dev, 39 struct iio_chan_spec const *channel, int *val, 40 int *val2, long mask) 41 { 42 int ret, temperature; 43 unsigned int humidity; 44 struct ms_ht_dev *dev_data = iio_priv(indio_dev); 45 46 switch (mask) { 47 case IIO_CHAN_INFO_PROCESSED: 48 switch (channel->type) { 49 case IIO_TEMP: /* in milli °C */ 50 ret = ms_sensors_ht_read_temperature(dev_data, 51 &temperature); 52 if (ret) 53 return ret; 54 *val = temperature; 55 56 return IIO_VAL_INT; 57 case IIO_HUMIDITYRELATIVE: /* in milli %RH */ 58 ret = ms_sensors_ht_read_humidity(dev_data, 59 &humidity); 60 if (ret) 61 return ret; 62 *val = humidity; 63 64 return IIO_VAL_INT; 65 default: 66 return -EINVAL; 67 } 68 case IIO_CHAN_INFO_SAMP_FREQ: 69 *val = htu21_samp_freq[dev_data->res_index]; 70 71 return IIO_VAL_INT; 72 default: 73 return -EINVAL; 74 } 75 } 76 77 static int htu21_write_raw(struct iio_dev *indio_dev, 78 struct iio_chan_spec const *chan, 79 int val, int val2, long mask) 80 { 81 struct ms_ht_dev *dev_data = iio_priv(indio_dev); 82 int i, ret; 83 84 switch (mask) { 85 case IIO_CHAN_INFO_SAMP_FREQ: 86 i = ARRAY_SIZE(htu21_samp_freq); 87 while (i-- > 0) 88 if (val == htu21_samp_freq[i]) 89 break; 90 if (i < 0) 91 return -EINVAL; 92 mutex_lock(&dev_data->lock); 93 dev_data->res_index = i; 94 ret = ms_sensors_write_resolution(dev_data, i); 95 mutex_unlock(&dev_data->lock); 96 97 return ret; 98 default: 99 return -EINVAL; 100 } 101 } 102 103 static const struct iio_chan_spec htu21_channels[] = { 104 { 105 .type = IIO_TEMP, 106 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED), 107 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), 108 }, 109 { 110 .type = IIO_HUMIDITYRELATIVE, 111 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED), 112 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), 113 } 114 }; 115 116 /* 117 * Meas Spec recommendation is to not read temperature 118 * on this driver part for MS8607 119 */ 120 static const struct iio_chan_spec ms8607_channels[] = { 121 { 122 .type = IIO_HUMIDITYRELATIVE, 123 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED), 124 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), 125 } 126 }; 127 128 static ssize_t htu21_show_battery_low(struct device *dev, 129 struct device_attribute *attr, char *buf) 130 { 131 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 132 struct ms_ht_dev *dev_data = iio_priv(indio_dev); 133 134 return ms_sensors_show_battery_low(dev_data, buf); 135 } 136 137 static ssize_t htu21_show_heater(struct device *dev, 138 struct device_attribute *attr, char *buf) 139 { 140 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 141 struct ms_ht_dev *dev_data = iio_priv(indio_dev); 142 143 return ms_sensors_show_heater(dev_data, buf); 144 } 145 146 static ssize_t htu21_write_heater(struct device *dev, 147 struct device_attribute *attr, 148 const char *buf, size_t len) 149 { 150 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 151 struct ms_ht_dev *dev_data = iio_priv(indio_dev); 152 153 return ms_sensors_write_heater(dev_data, buf, len); 154 } 155 156 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq); 157 static IIO_DEVICE_ATTR(battery_low, S_IRUGO, 158 htu21_show_battery_low, NULL, 0); 159 static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR, 160 htu21_show_heater, htu21_write_heater, 0); 161 162 static struct attribute *htu21_attributes[] = { 163 &iio_const_attr_sampling_frequency_available.dev_attr.attr, 164 &iio_dev_attr_battery_low.dev_attr.attr, 165 &iio_dev_attr_heater_enable.dev_attr.attr, 166 NULL, 167 }; 168 169 static const struct attribute_group htu21_attribute_group = { 170 .attrs = htu21_attributes, 171 }; 172 173 static const struct iio_info htu21_info = { 174 .read_raw = htu21_read_raw, 175 .write_raw = htu21_write_raw, 176 .attrs = &htu21_attribute_group, 177 }; 178 179 static int htu21_probe(struct i2c_client *client, 180 const struct i2c_device_id *id) 181 { 182 struct ms_ht_dev *dev_data; 183 struct iio_dev *indio_dev; 184 int ret; 185 u64 serial_number; 186 187 if (!i2c_check_functionality(client->adapter, 188 I2C_FUNC_SMBUS_WRITE_BYTE_DATA | 189 I2C_FUNC_SMBUS_WRITE_BYTE | 190 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { 191 dev_err(&client->dev, 192 "Adapter does not support some i2c transaction\n"); 193 return -EOPNOTSUPP; 194 } 195 196 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data)); 197 if (!indio_dev) 198 return -ENOMEM; 199 200 dev_data = iio_priv(indio_dev); 201 dev_data->client = client; 202 dev_data->res_index = 0; 203 mutex_init(&dev_data->lock); 204 205 indio_dev->info = &htu21_info; 206 indio_dev->name = id->name; 207 indio_dev->modes = INDIO_DIRECT_MODE; 208 209 if (id->driver_data == MS8607) { 210 indio_dev->channels = ms8607_channels; 211 indio_dev->num_channels = ARRAY_SIZE(ms8607_channels); 212 } else { 213 indio_dev->channels = htu21_channels; 214 indio_dev->num_channels = ARRAY_SIZE(htu21_channels); 215 } 216 217 i2c_set_clientdata(client, indio_dev); 218 219 ret = ms_sensors_reset(client, HTU21_RESET, 15000); 220 if (ret) 221 return ret; 222 223 ret = ms_sensors_read_serial(client, &serial_number); 224 if (ret) 225 return ret; 226 dev_info(&client->dev, "Serial number : %llx", serial_number); 227 228 return devm_iio_device_register(&client->dev, indio_dev); 229 } 230 231 static const struct i2c_device_id htu21_id[] = { 232 {"htu21", HTU21}, 233 {"ms8607-humidity", MS8607}, 234 {} 235 }; 236 MODULE_DEVICE_TABLE(i2c, htu21_id); 237 238 static const struct of_device_id htu21_of_match[] = { 239 { .compatible = "meas,htu21", }, 240 { .compatible = "meas,ms8607-humidity", }, 241 { }, 242 }; 243 MODULE_DEVICE_TABLE(of, htu21_of_match); 244 245 static struct i2c_driver htu21_driver = { 246 .probe = htu21_probe, 247 .id_table = htu21_id, 248 .driver = { 249 .name = "htu21", 250 .of_match_table = of_match_ptr(htu21_of_match), 251 }, 252 }; 253 254 module_i2c_driver(htu21_driver); 255 256 MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver"); 257 MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>"); 258 MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>"); 259 MODULE_LICENSE("GPL v2"); 260