xref: /openbmc/linux/drivers/iio/humidity/hdc2010.c (revision c699ce1a)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * hdc2010.c - Support for the TI HDC2010 and HDC2080
4  * temperature + relative humidity sensors
5  *
6  * Copyright (C) 2020 Norphonic AS
7  * Author: Eugene Zaikonnikov <ez@norphonic.com>
8  *
9  * Datasheet: https://www.ti.com/product/HDC2010/datasheet
10  * Datasheet: https://www.ti.com/product/HDC2080/datasheet
11  */
12 
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/i2c.h>
16 #include <linux/bitops.h>
17 
18 #include <linux/iio/iio.h>
19 #include <linux/iio/sysfs.h>
20 
21 #define HDC2010_REG_TEMP_LOW			0x00
22 #define HDC2010_REG_TEMP_HIGH			0x01
23 #define HDC2010_REG_HUMIDITY_LOW		0x02
24 #define HDC2010_REG_HUMIDITY_HIGH		0x03
25 #define HDC2010_REG_INTERRUPT_DRDY		0x04
26 #define HDC2010_REG_TEMP_MAX			0x05
27 #define HDC2010_REG_HUMIDITY_MAX		0x06
28 #define HDC2010_REG_INTERRUPT_EN		0x07
29 #define HDC2010_REG_TEMP_OFFSET_ADJ		0x08
30 #define HDC2010_REG_HUMIDITY_OFFSET_ADJ		0x09
31 #define HDC2010_REG_TEMP_THR_L			0x0a
32 #define HDC2010_REG_TEMP_THR_H			0x0b
33 #define HDC2010_REG_RH_THR_L			0x0c
34 #define HDC2010_REG_RH_THR_H			0x0d
35 #define HDC2010_REG_RESET_DRDY_INT_CONF		0x0e
36 #define HDC2010_REG_MEASUREMENT_CONF		0x0f
37 
38 #define HDC2010_MEAS_CONF			GENMASK(2, 1)
39 #define HDC2010_MEAS_TRIG			BIT(0)
40 #define HDC2010_HEATER_EN			BIT(3)
41 #define HDC2010_AMM				GENMASK(6, 4)
42 
43 struct hdc2010_data {
44 	struct i2c_client *client;
45 	struct mutex lock;
46 	u8 measurement_config;
47 	u8 interrupt_config;
48 	u8 drdy_config;
49 };
50 
51 enum hdc2010_addr_groups {
52 	HDC2010_GROUP_TEMP = 0,
53 	HDC2010_GROUP_HUMIDITY,
54 };
55 
56 struct hdc2010_reg_record {
57 	unsigned long primary;
58 	unsigned long peak;
59 };
60 
61 static const struct hdc2010_reg_record hdc2010_reg_translation[] = {
62 	[HDC2010_GROUP_TEMP] = {
63 		.primary = HDC2010_REG_TEMP_LOW,
64 		.peak = HDC2010_REG_TEMP_MAX,
65 	},
66 	[HDC2010_GROUP_HUMIDITY] = {
67 		.primary = HDC2010_REG_HUMIDITY_LOW,
68 		.peak = HDC2010_REG_HUMIDITY_MAX,
69 	},
70 };
71 
72 static IIO_CONST_ATTR(out_current_heater_raw_available, "0 1");
73 
74 static struct attribute *hdc2010_attributes[] = {
75 	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
76 	NULL
77 };
78 
79 static const struct attribute_group hdc2010_attribute_group = {
80 	.attrs = hdc2010_attributes,
81 };
82 
83 static const struct iio_chan_spec hdc2010_channels[] = {
84 	{
85 		.type = IIO_TEMP,
86 		.address = HDC2010_GROUP_TEMP,
87 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
88 			BIT(IIO_CHAN_INFO_PEAK) |
89 			BIT(IIO_CHAN_INFO_OFFSET) |
90 			BIT(IIO_CHAN_INFO_SCALE),
91 	},
92 	{
93 		.type = IIO_HUMIDITYRELATIVE,
94 		.address = HDC2010_GROUP_HUMIDITY,
95 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
96 			BIT(IIO_CHAN_INFO_PEAK) |
97 			BIT(IIO_CHAN_INFO_SCALE),
98 	},
99 	{
100 		.type = IIO_CURRENT,
101 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
102 		.extend_name = "heater",
103 		.output = 1,
104 	},
105 };
106 
107 static int hdc2010_update_drdy_config(struct hdc2010_data *data,
108 					     char mask, char val)
109 {
110 	u8 tmp = (~mask & data->drdy_config) | val;
111 	int ret;
112 
113 	ret = i2c_smbus_write_byte_data(data->client,
114 					HDC2010_REG_RESET_DRDY_INT_CONF, tmp);
115 	if (ret)
116 		return ret;
117 
118 	data->drdy_config = tmp;
119 
120 	return 0;
121 }
122 
123 static int hdc2010_get_prim_measurement_word(struct hdc2010_data *data,
124 					     struct iio_chan_spec const *chan)
125 {
126 	struct i2c_client *client = data->client;
127 	s32 ret;
128 
129 	ret = i2c_smbus_read_word_data(client,
130 			hdc2010_reg_translation[chan->address].primary);
131 
132 	if (ret < 0)
133 		dev_err(&client->dev, "Could not read sensor measurement word\n");
134 
135 	return ret;
136 }
137 
138 static int hdc2010_get_peak_measurement_byte(struct hdc2010_data *data,
139 					     struct iio_chan_spec const *chan)
140 {
141 	struct i2c_client *client = data->client;
142 	s32 ret;
143 
144 	ret = i2c_smbus_read_byte_data(client,
145 			hdc2010_reg_translation[chan->address].peak);
146 
147 	if (ret < 0)
148 		dev_err(&client->dev, "Could not read sensor measurement byte\n");
149 
150 	return ret;
151 }
152 
153 static int hdc2010_get_heater_status(struct hdc2010_data *data)
154 {
155 	return !!(data->drdy_config & HDC2010_HEATER_EN);
156 }
157 
158 static int hdc2010_read_raw(struct iio_dev *indio_dev,
159 			    struct iio_chan_spec const *chan, int *val,
160 			    int *val2, long mask)
161 {
162 	struct hdc2010_data *data = iio_priv(indio_dev);
163 
164 	switch (mask) {
165 	case IIO_CHAN_INFO_RAW: {
166 		int ret;
167 
168 		if (chan->type == IIO_CURRENT) {
169 			*val = hdc2010_get_heater_status(data);
170 			return IIO_VAL_INT;
171 		}
172 		ret = iio_device_claim_direct_mode(indio_dev);
173 		if (ret)
174 			return ret;
175 		mutex_lock(&data->lock);
176 		ret = hdc2010_get_prim_measurement_word(data, chan);
177 		mutex_unlock(&data->lock);
178 		iio_device_release_direct_mode(indio_dev);
179 		if (ret < 0)
180 			return ret;
181 		*val = ret;
182 		return IIO_VAL_INT;
183 	}
184 	case IIO_CHAN_INFO_PEAK: {
185 		int ret;
186 
187 		ret = iio_device_claim_direct_mode(indio_dev);
188 		if (ret)
189 			return ret;
190 		mutex_lock(&data->lock);
191 		ret = hdc2010_get_peak_measurement_byte(data, chan);
192 		mutex_unlock(&data->lock);
193 		iio_device_release_direct_mode(indio_dev);
194 		if (ret < 0)
195 			return ret;
196 		/* Scaling up the value so we can use same offset as RAW */
197 		*val = ret * 256;
198 		return IIO_VAL_INT;
199 	}
200 	case IIO_CHAN_INFO_SCALE:
201 		*val2 = 65536;
202 		if (chan->type == IIO_TEMP)
203 			*val = 165000;
204 		else
205 			*val = 100000;
206 		return IIO_VAL_FRACTIONAL;
207 	case IIO_CHAN_INFO_OFFSET:
208 		*val = -15887;
209 		*val2 = 515151;
210 		return IIO_VAL_INT_PLUS_MICRO;
211 	default:
212 		return -EINVAL;
213 	}
214 }
215 
216 static int hdc2010_write_raw(struct iio_dev *indio_dev,
217 			     struct iio_chan_spec const *chan,
218 			     int val, int val2, long mask)
219 {
220 	struct hdc2010_data *data = iio_priv(indio_dev);
221 	int new, ret;
222 
223 	switch (mask) {
224 	case IIO_CHAN_INFO_RAW:
225 		if (chan->type != IIO_CURRENT || val2 != 0)
226 			return -EINVAL;
227 
228 		switch (val) {
229 		case 1:
230 			new = HDC2010_HEATER_EN;
231 			break;
232 		case 0:
233 			new = 0;
234 			break;
235 		default:
236 			return -EINVAL;
237 		}
238 
239 		mutex_lock(&data->lock);
240 		ret = hdc2010_update_drdy_config(data, HDC2010_HEATER_EN, new);
241 		mutex_unlock(&data->lock);
242 		return ret;
243 	default:
244 		return -EINVAL;
245 	}
246 }
247 
248 static const struct iio_info hdc2010_info = {
249 	.read_raw = hdc2010_read_raw,
250 	.write_raw = hdc2010_write_raw,
251 	.attrs = &hdc2010_attribute_group,
252 };
253 
254 static int hdc2010_probe(struct i2c_client *client)
255 {
256 	struct iio_dev *indio_dev;
257 	struct hdc2010_data *data;
258 	u8 tmp;
259 	int ret;
260 
261 	if (!i2c_check_functionality(client->adapter,
262 	    I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
263 		return -EOPNOTSUPP;
264 
265 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
266 	if (!indio_dev)
267 		return -ENOMEM;
268 
269 	data = iio_priv(indio_dev);
270 	i2c_set_clientdata(client, indio_dev);
271 	data->client = client;
272 	mutex_init(&data->lock);
273 
274 	/*
275 	 * As DEVICE ID register does not differentiate between
276 	 * HDC2010 and HDC2080, we have the name hardcoded
277 	 */
278 	indio_dev->name = "hdc2010";
279 	indio_dev->modes = INDIO_DIRECT_MODE;
280 	indio_dev->info = &hdc2010_info;
281 
282 	indio_dev->channels = hdc2010_channels;
283 	indio_dev->num_channels = ARRAY_SIZE(hdc2010_channels);
284 
285 	/* Enable Automatic Measurement Mode at 5Hz */
286 	ret = hdc2010_update_drdy_config(data, HDC2010_AMM, HDC2010_AMM);
287 	if (ret)
288 		return ret;
289 
290 	/*
291 	 * We enable both temp and humidity measurement.
292 	 * However the measurement won't start even in AMM until triggered.
293 	 */
294 	tmp = (data->measurement_config & ~HDC2010_MEAS_CONF) |
295 		HDC2010_MEAS_TRIG;
296 
297 	ret = i2c_smbus_write_byte_data(client, HDC2010_REG_MEASUREMENT_CONF, tmp);
298 	if (ret) {
299 		dev_warn(&client->dev, "Unable to set up measurement\n");
300 		if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
301 			dev_warn(&client->dev, "Unable to restore default AMM\n");
302 		return ret;
303 	}
304 
305 	data->measurement_config = tmp;
306 
307 	return iio_device_register(indio_dev);
308 }
309 
310 static void hdc2010_remove(struct i2c_client *client)
311 {
312 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
313 	struct hdc2010_data *data = iio_priv(indio_dev);
314 
315 	iio_device_unregister(indio_dev);
316 
317 	/* Disable Automatic Measurement Mode */
318 	if (hdc2010_update_drdy_config(data, HDC2010_AMM, 0))
319 		dev_warn(&client->dev, "Unable to restore default AMM\n");
320 }
321 
322 static const struct i2c_device_id hdc2010_id[] = {
323 	{ "hdc2010" },
324 	{ "hdc2080" },
325 	{ }
326 };
327 MODULE_DEVICE_TABLE(i2c, hdc2010_id);
328 
329 static const struct of_device_id hdc2010_dt_ids[] = {
330 	{ .compatible = "ti,hdc2010" },
331 	{ .compatible = "ti,hdc2080" },
332 	{ }
333 };
334 MODULE_DEVICE_TABLE(of, hdc2010_dt_ids);
335 
336 static struct i2c_driver hdc2010_driver = {
337 	.driver = {
338 		.name	= "hdc2010",
339 		.of_match_table = hdc2010_dt_ids,
340 	},
341 	.probe_new = hdc2010_probe,
342 	.remove = hdc2010_remove,
343 	.id_table = hdc2010_id,
344 };
345 module_i2c_driver(hdc2010_driver);
346 
347 MODULE_AUTHOR("Eugene Zaikonnikov <ez@norphonic.com>");
348 MODULE_DESCRIPTION("TI HDC2010 humidity and temperature sensor driver");
349 MODULE_LICENSE("GPL");
350