xref: /openbmc/linux/drivers/iio/humidity/hdc100x.c (revision 5d331b7f)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * hdc100x.c - Support for the TI HDC100x temperature + humidity sensors
4  *
5  * Copyright (C) 2015, 2018
6  * Author: Matt Ranostay <matt.ranostay@konsulko.com>
7  *
8  * Datasheets:
9  * http://www.ti.com/product/HDC1000/datasheet
10  * http://www.ti.com/product/HDC1008/datasheet
11  * http://www.ti.com/product/HDC1010/datasheet
12  * http://www.ti.com/product/HDC1050/datasheet
13  * http://www.ti.com/product/HDC1080/datasheet
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/module.h>
18 #include <linux/init.h>
19 #include <linux/i2c.h>
20 
21 #include <linux/iio/iio.h>
22 #include <linux/iio/sysfs.h>
23 #include <linux/iio/buffer.h>
24 #include <linux/iio/trigger_consumer.h>
25 #include <linux/iio/triggered_buffer.h>
26 
27 #define HDC100X_REG_TEMP			0x00
28 #define HDC100X_REG_HUMIDITY			0x01
29 
30 #define HDC100X_REG_CONFIG			0x02
31 #define HDC100X_REG_CONFIG_ACQ_MODE		BIT(12)
32 #define HDC100X_REG_CONFIG_HEATER_EN		BIT(13)
33 
34 struct hdc100x_data {
35 	struct i2c_client *client;
36 	struct mutex lock;
37 	u16 config;
38 
39 	/* integration time of the sensor */
40 	int adc_int_us[2];
41 };
42 
43 /* integration time in us */
44 static const int hdc100x_int_time[][3] = {
45 	{ 6350, 3650, 0 },	/* IIO_TEMP channel*/
46 	{ 6500, 3850, 2500 },	/* IIO_HUMIDITYRELATIVE channel */
47 };
48 
49 /* HDC100X_REG_CONFIG shift and mask values */
50 static const struct {
51 	int shift;
52 	int mask;
53 } hdc100x_resolution_shift[2] = {
54 	{ /* IIO_TEMP channel */
55 		.shift = 10,
56 		.mask = 1
57 	},
58 	{ /* IIO_HUMIDITYRELATIVE channel */
59 		.shift = 8,
60 		.mask = 3,
61 	},
62 };
63 
64 static IIO_CONST_ATTR(temp_integration_time_available,
65 		"0.00365 0.00635");
66 
67 static IIO_CONST_ATTR(humidityrelative_integration_time_available,
68 		"0.0025 0.00385 0.0065");
69 
70 static IIO_CONST_ATTR(out_current_heater_raw_available,
71 		"0 1");
72 
73 static struct attribute *hdc100x_attributes[] = {
74 	&iio_const_attr_temp_integration_time_available.dev_attr.attr,
75 	&iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
76 	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
77 	NULL
78 };
79 
80 static const struct attribute_group hdc100x_attribute_group = {
81 	.attrs = hdc100x_attributes,
82 };
83 
84 static const struct iio_chan_spec hdc100x_channels[] = {
85 	{
86 		.type = IIO_TEMP,
87 		.address = HDC100X_REG_TEMP,
88 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
89 			BIT(IIO_CHAN_INFO_SCALE) |
90 			BIT(IIO_CHAN_INFO_INT_TIME) |
91 			BIT(IIO_CHAN_INFO_OFFSET),
92 		.scan_index = 0,
93 		.scan_type = {
94 			.sign = 's',
95 			.realbits = 16,
96 			.storagebits = 16,
97 			.endianness = IIO_BE,
98 		},
99 	},
100 	{
101 		.type = IIO_HUMIDITYRELATIVE,
102 		.address = HDC100X_REG_HUMIDITY,
103 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
104 			BIT(IIO_CHAN_INFO_SCALE) |
105 			BIT(IIO_CHAN_INFO_INT_TIME),
106 		.scan_index = 1,
107 		.scan_type = {
108 			.sign = 'u',
109 			.realbits = 16,
110 			.storagebits = 16,
111 			.endianness = IIO_BE,
112 		},
113 	},
114 	{
115 		.type = IIO_CURRENT,
116 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
117 		.extend_name = "heater",
118 		.output = 1,
119 		.scan_index = -1,
120 	},
121 	IIO_CHAN_SOFT_TIMESTAMP(2),
122 };
123 
124 static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
125 
126 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
127 {
128 	int tmp = (~mask & data->config) | val;
129 	int ret;
130 
131 	ret = i2c_smbus_write_word_swapped(data->client,
132 						HDC100X_REG_CONFIG, tmp);
133 	if (!ret)
134 		data->config = tmp;
135 
136 	return ret;
137 }
138 
139 static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
140 {
141 	int shift = hdc100x_resolution_shift[chan].shift;
142 	int ret = -EINVAL;
143 	int i;
144 
145 	for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
146 		if (val2 && val2 == hdc100x_int_time[chan][i]) {
147 			ret = hdc100x_update_config(data,
148 				hdc100x_resolution_shift[chan].mask << shift,
149 				i << shift);
150 			if (!ret)
151 				data->adc_int_us[chan] = val2;
152 			break;
153 		}
154 	}
155 
156 	return ret;
157 }
158 
159 static int hdc100x_get_measurement(struct hdc100x_data *data,
160 				   struct iio_chan_spec const *chan)
161 {
162 	struct i2c_client *client = data->client;
163 	int delay = data->adc_int_us[chan->address];
164 	int ret;
165 	__be16 val;
166 
167 	/* start measurement */
168 	ret = i2c_smbus_write_byte(client, chan->address);
169 	if (ret < 0) {
170 		dev_err(&client->dev, "cannot start measurement");
171 		return ret;
172 	}
173 
174 	/* wait for integration time to pass */
175 	usleep_range(delay, delay + 1000);
176 
177 	/* read measurement */
178 	ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
179 	if (ret < 0) {
180 		dev_err(&client->dev, "cannot read sensor data\n");
181 		return ret;
182 	}
183 	return be16_to_cpu(val);
184 }
185 
186 static int hdc100x_get_heater_status(struct hdc100x_data *data)
187 {
188 	return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
189 }
190 
191 static int hdc100x_read_raw(struct iio_dev *indio_dev,
192 			    struct iio_chan_spec const *chan, int *val,
193 			    int *val2, long mask)
194 {
195 	struct hdc100x_data *data = iio_priv(indio_dev);
196 
197 	switch (mask) {
198 	case IIO_CHAN_INFO_RAW: {
199 		int ret;
200 
201 		mutex_lock(&data->lock);
202 		if (chan->type == IIO_CURRENT) {
203 			*val = hdc100x_get_heater_status(data);
204 			ret = IIO_VAL_INT;
205 		} else {
206 			ret = iio_device_claim_direct_mode(indio_dev);
207 			if (ret) {
208 				mutex_unlock(&data->lock);
209 				return ret;
210 			}
211 
212 			ret = hdc100x_get_measurement(data, chan);
213 			iio_device_release_direct_mode(indio_dev);
214 			if (ret >= 0) {
215 				*val = ret;
216 				ret = IIO_VAL_INT;
217 			}
218 		}
219 		mutex_unlock(&data->lock);
220 		return ret;
221 	}
222 	case IIO_CHAN_INFO_INT_TIME:
223 		*val = 0;
224 		*val2 = data->adc_int_us[chan->address];
225 		return IIO_VAL_INT_PLUS_MICRO;
226 	case IIO_CHAN_INFO_SCALE:
227 		if (chan->type == IIO_TEMP) {
228 			*val = 165000;
229 			*val2 = 65536;
230 			return IIO_VAL_FRACTIONAL;
231 		} else {
232 			*val = 100;
233 			*val2 = 65536;
234 			return IIO_VAL_FRACTIONAL;
235 		}
236 		break;
237 	case IIO_CHAN_INFO_OFFSET:
238 		*val = -15887;
239 		*val2 = 515151;
240 		return IIO_VAL_INT_PLUS_MICRO;
241 	default:
242 		return -EINVAL;
243 	}
244 }
245 
246 static int hdc100x_write_raw(struct iio_dev *indio_dev,
247 			     struct iio_chan_spec const *chan,
248 			     int val, int val2, long mask)
249 {
250 	struct hdc100x_data *data = iio_priv(indio_dev);
251 	int ret = -EINVAL;
252 
253 	switch (mask) {
254 	case IIO_CHAN_INFO_INT_TIME:
255 		if (val != 0)
256 			return -EINVAL;
257 
258 		mutex_lock(&data->lock);
259 		ret = hdc100x_set_it_time(data, chan->address, val2);
260 		mutex_unlock(&data->lock);
261 		return ret;
262 	case IIO_CHAN_INFO_RAW:
263 		if (chan->type != IIO_CURRENT || val2 != 0)
264 			return -EINVAL;
265 
266 		mutex_lock(&data->lock);
267 		ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
268 					val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
269 		mutex_unlock(&data->lock);
270 		return ret;
271 	default:
272 		return -EINVAL;
273 	}
274 }
275 
276 static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
277 {
278 	struct hdc100x_data *data = iio_priv(indio_dev);
279 	int ret;
280 
281 	/* Buffer is enabled. First set ACQ Mode, then attach poll func */
282 	mutex_lock(&data->lock);
283 	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
284 				    HDC100X_REG_CONFIG_ACQ_MODE);
285 	mutex_unlock(&data->lock);
286 	if (ret)
287 		return ret;
288 
289 	return iio_triggered_buffer_postenable(indio_dev);
290 }
291 
292 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
293 {
294 	struct hdc100x_data *data = iio_priv(indio_dev);
295 	int ret;
296 
297 	/* First detach poll func, then reset ACQ mode. OK to disable buffer */
298 	ret = iio_triggered_buffer_predisable(indio_dev);
299 	if (ret)
300 		return ret;
301 
302 	mutex_lock(&data->lock);
303 	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
304 	mutex_unlock(&data->lock);
305 
306 	return ret;
307 }
308 
309 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
310 	.postenable  = hdc100x_buffer_postenable,
311 	.predisable  = hdc100x_buffer_predisable,
312 };
313 
314 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
315 {
316 	struct iio_poll_func *pf = p;
317 	struct iio_dev *indio_dev = pf->indio_dev;
318 	struct hdc100x_data *data = iio_priv(indio_dev);
319 	struct i2c_client *client = data->client;
320 	int delay = data->adc_int_us[0] + data->adc_int_us[1];
321 	int ret;
322 	s16 buf[8];  /* 2x s16 + padding + 8 byte timestamp */
323 
324 	/* dual read starts at temp register */
325 	mutex_lock(&data->lock);
326 	ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
327 	if (ret < 0) {
328 		dev_err(&client->dev, "cannot start measurement\n");
329 		goto err;
330 	}
331 	usleep_range(delay, delay + 1000);
332 
333 	ret = i2c_master_recv(client, (u8 *)buf, 4);
334 	if (ret < 0) {
335 		dev_err(&client->dev, "cannot read sensor data\n");
336 		goto err;
337 	}
338 
339 	iio_push_to_buffers_with_timestamp(indio_dev, buf,
340 					   iio_get_time_ns(indio_dev));
341 err:
342 	mutex_unlock(&data->lock);
343 	iio_trigger_notify_done(indio_dev->trig);
344 
345 	return IRQ_HANDLED;
346 }
347 
348 static const struct iio_info hdc100x_info = {
349 	.read_raw = hdc100x_read_raw,
350 	.write_raw = hdc100x_write_raw,
351 	.attrs = &hdc100x_attribute_group,
352 };
353 
354 static int hdc100x_probe(struct i2c_client *client,
355 			 const struct i2c_device_id *id)
356 {
357 	struct iio_dev *indio_dev;
358 	struct hdc100x_data *data;
359 	int ret;
360 
361 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
362 				     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
363 		return -EOPNOTSUPP;
364 
365 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
366 	if (!indio_dev)
367 		return -ENOMEM;
368 
369 	data = iio_priv(indio_dev);
370 	i2c_set_clientdata(client, indio_dev);
371 	data->client = client;
372 	mutex_init(&data->lock);
373 
374 	indio_dev->dev.parent = &client->dev;
375 	indio_dev->name = dev_name(&client->dev);
376 	indio_dev->modes = INDIO_DIRECT_MODE;
377 	indio_dev->info = &hdc100x_info;
378 
379 	indio_dev->channels = hdc100x_channels;
380 	indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
381 	indio_dev->available_scan_masks = hdc100x_scan_masks;
382 
383 	/* be sure we are in a known state */
384 	hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
385 	hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
386 	hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
387 
388 	ret = iio_triggered_buffer_setup(indio_dev, NULL,
389 					 hdc100x_trigger_handler,
390 					 &hdc_buffer_setup_ops);
391 	if (ret < 0) {
392 		dev_err(&client->dev, "iio triggered buffer setup failed\n");
393 		return ret;
394 	}
395 	ret = iio_device_register(indio_dev);
396 	if (ret < 0)
397 		iio_triggered_buffer_cleanup(indio_dev);
398 
399 	return ret;
400 }
401 
402 static int hdc100x_remove(struct i2c_client *client)
403 {
404 	struct iio_dev *indio_dev = i2c_get_clientdata(client);
405 
406 	iio_device_unregister(indio_dev);
407 	iio_triggered_buffer_cleanup(indio_dev);
408 
409 	return 0;
410 }
411 
412 static const struct i2c_device_id hdc100x_id[] = {
413 	{ "hdc100x", 0 },
414 	{ "hdc1000", 0 },
415 	{ "hdc1008", 0 },
416 	{ "hdc1010", 0 },
417 	{ "hdc1050", 0 },
418 	{ "hdc1080", 0 },
419 	{ }
420 };
421 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
422 
423 static const struct of_device_id hdc100x_dt_ids[] = {
424 	{ .compatible = "ti,hdc1000" },
425 	{ .compatible = "ti,hdc1008" },
426 	{ .compatible = "ti,hdc1010" },
427 	{ .compatible = "ti,hdc1050" },
428 	{ .compatible = "ti,hdc1080" },
429 	{ }
430 };
431 MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
432 
433 static struct i2c_driver hdc100x_driver = {
434 	.driver = {
435 		.name	= "hdc100x",
436 		.of_match_table = of_match_ptr(hdc100x_dt_ids),
437 	},
438 	.probe = hdc100x_probe,
439 	.remove = hdc100x_remove,
440 	.id_table = hdc100x_id,
441 };
442 module_i2c_driver(hdc100x_driver);
443 
444 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
445 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
446 MODULE_LICENSE("GPL");
447