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
43struct 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
51enum hdc2010_addr_groups {
52	HDC2010_GROUP_TEMP = 0,
53	HDC2010_GROUP_HUMIDITY,
54};
55
56struct hdc2010_reg_record {
57	unsigned long primary;
58	unsigned long peak;
59};
60
61static 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
72static IIO_CONST_ATTR(out_current_heater_raw_available, "0 1");
73
74static struct attribute *hdc2010_attributes[] = {
75	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
76	NULL
77};
78
79static const struct attribute_group hdc2010_attribute_group = {
80	.attrs = hdc2010_attributes,
81};
82
83static 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
107static 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
123static 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
138static 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
153static int hdc2010_get_heater_status(struct hdc2010_data *data)
154{
155	return !!(data->drdy_config & HDC2010_HEATER_EN);
156}
157
158static 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
216static 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
248static 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
254static 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
310static 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
322static const struct i2c_device_id hdc2010_id[] = {
323	{ "hdc2010" },
324	{ "hdc2080" },
325	{ }
326};
327MODULE_DEVICE_TABLE(i2c, hdc2010_id);
328
329static const struct of_device_id hdc2010_dt_ids[] = {
330	{ .compatible = "ti,hdc2010" },
331	{ .compatible = "ti,hdc2080" },
332	{ }
333};
334MODULE_DEVICE_TABLE(of, hdc2010_dt_ids);
335
336static struct i2c_driver hdc2010_driver = {
337	.driver = {
338		.name	= "hdc2010",
339		.of_match_table = hdc2010_dt_ids,
340	},
341	.probe = hdc2010_probe,
342	.remove = hdc2010_remove,
343	.id_table = hdc2010_id,
344};
345module_i2c_driver(hdc2010_driver);
346
347MODULE_AUTHOR("Eugene Zaikonnikov <ez@norphonic.com>");
348MODULE_DESCRIPTION("TI HDC2010 humidity and temperature sensor driver");
349MODULE_LICENSE("GPL");
350