x86/speculation/mds: Fix documentation typo
[linux/fpc-iii.git] / drivers / iio / humidity / htu21.c
blob2c4b9be85a05a95b7980ddb3b2146033a120c566
1 /*
2 * htu21.c - Support for Measurement-Specialties
3 * htu21 temperature & humidity sensor
4 * and humidity part of MS8607 sensor
6 * Copyright (c) 2014 Measurement-Specialties
8 * Licensed under the GPL-2.
10 * (7-bit I2C slave address 0x40)
12 * Datasheet:
13 * http://www.meas-spec.com/downloads/HTU21D.pdf
14 * Datasheet:
15 * http://www.meas-spec.com/downloads/MS8607-02BA01.pdf
18 #include <linux/init.h>
19 #include <linux/device.h>
20 #include <linux/kernel.h>
21 #include <linux/stat.h>
22 #include <linux/module.h>
23 #include <linux/iio/iio.h>
24 #include <linux/iio/sysfs.h>
26 #include "../common/ms_sensors/ms_sensors_i2c.h"
28 #define HTU21_RESET 0xFE
30 enum {
31 HTU21,
32 MS8607
35 static const int htu21_samp_freq[4] = { 20, 40, 70, 120 };
36 /* String copy of the above const for readability purpose */
37 static const char htu21_show_samp_freq[] = "20 40 70 120";
39 static int htu21_read_raw(struct iio_dev *indio_dev,
40 struct iio_chan_spec const *channel, int *val,
41 int *val2, long mask)
43 int ret, temperature;
44 unsigned int humidity;
45 struct ms_ht_dev *dev_data = iio_priv(indio_dev);
47 switch (mask) {
48 case IIO_CHAN_INFO_PROCESSED:
49 switch (channel->type) {
50 case IIO_TEMP: /* in milli °C */
51 ret = ms_sensors_ht_read_temperature(dev_data,
52 &temperature);
53 if (ret)
54 return ret;
55 *val = temperature;
57 return IIO_VAL_INT;
58 case IIO_HUMIDITYRELATIVE: /* in milli %RH */
59 ret = ms_sensors_ht_read_humidity(dev_data,
60 &humidity);
61 if (ret)
62 return ret;
63 *val = humidity;
65 return IIO_VAL_INT;
66 default:
67 return -EINVAL;
69 case IIO_CHAN_INFO_SAMP_FREQ:
70 *val = htu21_samp_freq[dev_data->res_index];
72 return IIO_VAL_INT;
73 default:
74 return -EINVAL;
78 static int htu21_write_raw(struct iio_dev *indio_dev,
79 struct iio_chan_spec const *chan,
80 int val, int val2, long mask)
82 struct ms_ht_dev *dev_data = iio_priv(indio_dev);
83 int i, ret;
85 switch (mask) {
86 case IIO_CHAN_INFO_SAMP_FREQ:
87 i = ARRAY_SIZE(htu21_samp_freq);
88 while (i-- > 0)
89 if (val == htu21_samp_freq[i])
90 break;
91 if (i < 0)
92 return -EINVAL;
93 mutex_lock(&dev_data->lock);
94 dev_data->res_index = i;
95 ret = ms_sensors_write_resolution(dev_data, i);
96 mutex_unlock(&dev_data->lock);
98 return ret;
99 default:
100 return -EINVAL;
104 static const struct iio_chan_spec htu21_channels[] = {
106 .type = IIO_TEMP,
107 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
108 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
111 .type = IIO_HUMIDITYRELATIVE,
112 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
113 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
118 * Meas Spec recommendation is to not read temperature
119 * on this driver part for MS8607
121 static const struct iio_chan_spec ms8607_channels[] = {
123 .type = IIO_HUMIDITYRELATIVE,
124 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_PROCESSED),
125 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
129 static ssize_t htu21_show_battery_low(struct device *dev,
130 struct device_attribute *attr, char *buf)
132 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
133 struct ms_ht_dev *dev_data = iio_priv(indio_dev);
135 return ms_sensors_show_battery_low(dev_data, buf);
138 static ssize_t htu21_show_heater(struct device *dev,
139 struct device_attribute *attr, char *buf)
141 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
142 struct ms_ht_dev *dev_data = iio_priv(indio_dev);
144 return ms_sensors_show_heater(dev_data, buf);
147 static ssize_t htu21_write_heater(struct device *dev,
148 struct device_attribute *attr,
149 const char *buf, size_t len)
151 struct iio_dev *indio_dev = dev_to_iio_dev(dev);
152 struct ms_ht_dev *dev_data = iio_priv(indio_dev);
154 return ms_sensors_write_heater(dev_data, buf, len);
157 static IIO_CONST_ATTR_SAMP_FREQ_AVAIL(htu21_show_samp_freq);
158 static IIO_DEVICE_ATTR(battery_low, S_IRUGO,
159 htu21_show_battery_low, NULL, 0);
160 static IIO_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,
161 htu21_show_heater, htu21_write_heater, 0);
163 static struct attribute *htu21_attributes[] = {
164 &iio_const_attr_sampling_frequency_available.dev_attr.attr,
165 &iio_dev_attr_battery_low.dev_attr.attr,
166 &iio_dev_attr_heater_enable.dev_attr.attr,
167 NULL,
170 static const struct attribute_group htu21_attribute_group = {
171 .attrs = htu21_attributes,
174 static const struct iio_info htu21_info = {
175 .read_raw = htu21_read_raw,
176 .write_raw = htu21_write_raw,
177 .attrs = &htu21_attribute_group,
178 .driver_module = THIS_MODULE,
181 static int htu21_probe(struct i2c_client *client,
182 const struct i2c_device_id *id)
184 struct ms_ht_dev *dev_data;
185 struct iio_dev *indio_dev;
186 int ret;
187 u64 serial_number;
189 if (!i2c_check_functionality(client->adapter,
190 I2C_FUNC_SMBUS_WRITE_BYTE_DATA |
191 I2C_FUNC_SMBUS_WRITE_BYTE |
192 I2C_FUNC_SMBUS_READ_I2C_BLOCK)) {
193 dev_err(&client->dev,
194 "Adapter does not support some i2c transaction\n");
195 return -EOPNOTSUPP;
198 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*dev_data));
199 if (!indio_dev)
200 return -ENOMEM;
202 dev_data = iio_priv(indio_dev);
203 dev_data->client = client;
204 dev_data->res_index = 0;
205 mutex_init(&dev_data->lock);
207 indio_dev->info = &htu21_info;
208 indio_dev->name = id->name;
209 indio_dev->dev.parent = &client->dev;
210 indio_dev->modes = INDIO_DIRECT_MODE;
212 if (id->driver_data == MS8607) {
213 indio_dev->channels = ms8607_channels;
214 indio_dev->num_channels = ARRAY_SIZE(ms8607_channels);
215 } else {
216 indio_dev->channels = htu21_channels;
217 indio_dev->num_channels = ARRAY_SIZE(htu21_channels);
220 i2c_set_clientdata(client, indio_dev);
222 ret = ms_sensors_reset(client, HTU21_RESET, 15000);
223 if (ret)
224 return ret;
226 ret = ms_sensors_read_serial(client, &serial_number);
227 if (ret)
228 return ret;
229 dev_info(&client->dev, "Serial number : %llx", serial_number);
231 return devm_iio_device_register(&client->dev, indio_dev);
234 static const struct i2c_device_id htu21_id[] = {
235 {"htu21", HTU21},
236 {"ms8607-humidity", MS8607},
239 MODULE_DEVICE_TABLE(i2c, htu21_id);
241 static const struct of_device_id htu21_of_match[] = {
242 { .compatible = "meas,htu21", },
243 { .compatible = "meas,ms8607-humidity", },
244 { },
246 MODULE_DEVICE_TABLE(of, htu21_of_match);
248 static struct i2c_driver htu21_driver = {
249 .probe = htu21_probe,
250 .id_table = htu21_id,
251 .driver = {
252 .name = "htu21",
253 .of_match_table = of_match_ptr(htu21_of_match),
257 module_i2c_driver(htu21_driver);
259 MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver");
260 MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>");
261 MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>");
262 MODULE_LICENSE("GPL v2");