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/mod_devicetable.h> |
23 | #include <linux/iio/iio.h> |
24 | #include <linux/iio/sysfs.h> |
25 | |
26 | #include "../common/ms_sensors/ms_sensors_i2c.h" |
27 | |
28 | #define HTU21_RESET 0xFE |
29 | |
30 | enum { |
31 | HTU21, |
32 | MS8607 |
33 | }; |
34 | |
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" ; |
38 | |
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) |
42 | { |
43 | int ret, temperature; |
44 | unsigned int humidity; |
45 | struct ms_ht_dev *dev_data = iio_priv(indio_dev); |
46 | |
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: &temperature); |
53 | if (ret) |
54 | return ret; |
55 | *val = temperature; |
56 | |
57 | return IIO_VAL_INT; |
58 | case IIO_HUMIDITYRELATIVE: /* in milli %RH */ |
59 | ret = ms_sensors_ht_read_humidity(dev_data, |
60 | humidity: &humidity); |
61 | if (ret) |
62 | return ret; |
63 | *val = humidity; |
64 | |
65 | return IIO_VAL_INT; |
66 | default: |
67 | return -EINVAL; |
68 | } |
69 | case IIO_CHAN_INFO_SAMP_FREQ: |
70 | *val = htu21_samp_freq[dev_data->res_index]; |
71 | |
72 | return IIO_VAL_INT; |
73 | default: |
74 | return -EINVAL; |
75 | } |
76 | } |
77 | |
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) |
81 | { |
82 | struct ms_ht_dev *dev_data = iio_priv(indio_dev); |
83 | int i, ret; |
84 | |
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(lock: &dev_data->lock); |
97 | |
98 | return ret; |
99 | default: |
100 | return -EINVAL; |
101 | } |
102 | } |
103 | |
104 | static const struct iio_chan_spec htu21_channels[] = { |
105 | { |
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), |
109 | }, |
110 | { |
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), |
114 | } |
115 | }; |
116 | |
117 | /* |
118 | * Meas Spec recommendation is to not read temperature |
119 | * on this driver part for MS8607 |
120 | */ |
121 | static const struct iio_chan_spec ms8607_channels[] = { |
122 | { |
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), |
126 | } |
127 | }; |
128 | |
129 | static ssize_t htu21_show_battery_low(struct device *dev, |
130 | struct device_attribute *attr, char *buf) |
131 | { |
132 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
133 | struct ms_ht_dev *dev_data = iio_priv(indio_dev); |
134 | |
135 | return ms_sensors_show_battery_low(dev_data, buf); |
136 | } |
137 | |
138 | static ssize_t htu21_show_heater(struct device *dev, |
139 | struct device_attribute *attr, char *buf) |
140 | { |
141 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
142 | struct ms_ht_dev *dev_data = iio_priv(indio_dev); |
143 | |
144 | return ms_sensors_show_heater(dev_data, buf); |
145 | } |
146 | |
147 | static ssize_t htu21_write_heater(struct device *dev, |
148 | struct device_attribute *attr, |
149 | const char *buf, size_t len) |
150 | { |
151 | struct iio_dev *indio_dev = dev_to_iio_dev(dev); |
152 | struct ms_ht_dev *dev_data = iio_priv(indio_dev); |
153 | |
154 | return ms_sensors_write_heater(dev_data, buf, len); |
155 | } |
156 | |
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); |
162 | |
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, |
168 | }; |
169 | |
170 | static const struct attribute_group htu21_attribute_group = { |
171 | .attrs = htu21_attributes, |
172 | }; |
173 | |
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 | }; |
179 | |
180 | static int htu21_probe(struct i2c_client *client) |
181 | { |
182 | const struct i2c_device_id *id = i2c_client_get_device_id(client); |
183 | struct ms_ht_dev *dev_data; |
184 | struct iio_dev *indio_dev; |
185 | int ret; |
186 | u64 serial_number; |
187 | |
188 | if (!i2c_check_functionality(adap: client->adapter, |
189 | I2C_FUNC_SMBUS_WRITE_BYTE_DATA | |
190 | I2C_FUNC_SMBUS_WRITE_BYTE | |
191 | I2C_FUNC_SMBUS_READ_I2C_BLOCK)) { |
192 | dev_err(&client->dev, |
193 | "Adapter does not support some i2c transaction\n" ); |
194 | return -EOPNOTSUPP; |
195 | } |
196 | |
197 | indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*dev_data)); |
198 | if (!indio_dev) |
199 | return -ENOMEM; |
200 | |
201 | dev_data = iio_priv(indio_dev); |
202 | dev_data->client = client; |
203 | dev_data->res_index = 0; |
204 | mutex_init(&dev_data->lock); |
205 | |
206 | indio_dev->info = &htu21_info; |
207 | indio_dev->name = id->name; |
208 | indio_dev->modes = INDIO_DIRECT_MODE; |
209 | |
210 | if (id->driver_data == MS8607) { |
211 | indio_dev->channels = ms8607_channels; |
212 | indio_dev->num_channels = ARRAY_SIZE(ms8607_channels); |
213 | } else { |
214 | indio_dev->channels = htu21_channels; |
215 | indio_dev->num_channels = ARRAY_SIZE(htu21_channels); |
216 | } |
217 | |
218 | i2c_set_clientdata(client, data: indio_dev); |
219 | |
220 | ret = ms_sensors_reset(cli: client, HTU21_RESET, delay: 15000); |
221 | if (ret) |
222 | return ret; |
223 | |
224 | ret = ms_sensors_read_serial(client, sn: &serial_number); |
225 | if (ret) |
226 | return ret; |
227 | dev_info(&client->dev, "Serial number : %llx" , serial_number); |
228 | |
229 | return devm_iio_device_register(&client->dev, indio_dev); |
230 | } |
231 | |
232 | static const struct i2c_device_id htu21_id[] = { |
233 | {"htu21" , HTU21}, |
234 | {"ms8607-humidity" , MS8607}, |
235 | {} |
236 | }; |
237 | MODULE_DEVICE_TABLE(i2c, htu21_id); |
238 | |
239 | static const struct of_device_id htu21_of_match[] = { |
240 | { .compatible = "meas,htu21" , }, |
241 | { .compatible = "meas,ms8607-humidity" , }, |
242 | { }, |
243 | }; |
244 | MODULE_DEVICE_TABLE(of, htu21_of_match); |
245 | |
246 | static struct i2c_driver htu21_driver = { |
247 | .probe = htu21_probe, |
248 | .id_table = htu21_id, |
249 | .driver = { |
250 | .name = "htu21" , |
251 | .of_match_table = htu21_of_match, |
252 | }, |
253 | }; |
254 | |
255 | module_i2c_driver(htu21_driver); |
256 | |
257 | MODULE_DESCRIPTION("Measurement-Specialties htu21 temperature and humidity driver" ); |
258 | MODULE_AUTHOR("William Markezana <william.markezana@meas-spec.com>" ); |
259 | MODULE_AUTHOR("Ludovic Tancerel <ludovic.tancerel@maplehightech.com>" ); |
260 | MODULE_LICENSE("GPL v2" ); |
261 | MODULE_IMPORT_NS(IIO_MEAS_SPEC_SENSORS); |
262 | |