xref: /openbmc/linux/drivers/iio/humidity/hdc100x.c (revision b8265621)
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 	/* Ensure natural alignment of timestamp */
42 	struct {
43 		__be16 channels[2];
44 		s64 ts __aligned(8);
45 	} scan;
46 };
47 
48 /* integration time in us */
49 static const int hdc100x_int_time[][3] = {
50 	{ 6350, 3650, 0 },	/* IIO_TEMP channel*/
51 	{ 6500, 3850, 2500 },	/* IIO_HUMIDITYRELATIVE channel */
52 };
53 
54 /* HDC100X_REG_CONFIG shift and mask values */
55 static const struct {
56 	int shift;
57 	int mask;
58 } hdc100x_resolution_shift[2] = {
59 	{ /* IIO_TEMP channel */
60 		.shift = 10,
61 		.mask = 1
62 	},
63 	{ /* IIO_HUMIDITYRELATIVE channel */
64 		.shift = 8,
65 		.mask = 3,
66 	},
67 };
68 
69 static IIO_CONST_ATTR(temp_integration_time_available,
70 		"0.00365 0.00635");
71 
72 static IIO_CONST_ATTR(humidityrelative_integration_time_available,
73 		"0.0025 0.00385 0.0065");
74 
75 static IIO_CONST_ATTR(out_current_heater_raw_available,
76 		"0 1");
77 
78 static struct attribute *hdc100x_attributes[] = {
79 	&iio_const_attr_temp_integration_time_available.dev_attr.attr,
80 	&iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
81 	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
82 	NULL
83 };
84 
85 static const struct attribute_group hdc100x_attribute_group = {
86 	.attrs = hdc100x_attributes,
87 };
88 
89 static const struct iio_chan_spec hdc100x_channels[] = {
90 	{
91 		.type = IIO_TEMP,
92 		.address = HDC100X_REG_TEMP,
93 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
94 			BIT(IIO_CHAN_INFO_SCALE) |
95 			BIT(IIO_CHAN_INFO_INT_TIME) |
96 			BIT(IIO_CHAN_INFO_OFFSET),
97 		.scan_index = 0,
98 		.scan_type = {
99 			.sign = 's',
100 			.realbits = 16,
101 			.storagebits = 16,
102 			.endianness = IIO_BE,
103 		},
104 	},
105 	{
106 		.type = IIO_HUMIDITYRELATIVE,
107 		.address = HDC100X_REG_HUMIDITY,
108 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
109 			BIT(IIO_CHAN_INFO_SCALE) |
110 			BIT(IIO_CHAN_INFO_INT_TIME),
111 		.scan_index = 1,
112 		.scan_type = {
113 			.sign = 'u',
114 			.realbits = 16,
115 			.storagebits = 16,
116 			.endianness = IIO_BE,
117 		},
118 	},
119 	{
120 		.type = IIO_CURRENT,
121 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
122 		.extend_name = "heater",
123 		.output = 1,
124 		.scan_index = -1,
125 	},
126 	IIO_CHAN_SOFT_TIMESTAMP(2),
127 };
128 
129 static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
130 
131 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
132 {
133 	int tmp = (~mask & data->config) | val;
134 	int ret;
135 
136 	ret = i2c_smbus_write_word_swapped(data->client,
137 						HDC100X_REG_CONFIG, tmp);
138 	if (!ret)
139 		data->config = tmp;
140 
141 	return ret;
142 }
143 
144 static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
145 {
146 	int shift = hdc100x_resolution_shift[chan].shift;
147 	int ret = -EINVAL;
148 	int i;
149 
150 	for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
151 		if (val2 && val2 == hdc100x_int_time[chan][i]) {
152 			ret = hdc100x_update_config(data,
153 				hdc100x_resolution_shift[chan].mask << shift,
154 				i << shift);
155 			if (!ret)
156 				data->adc_int_us[chan] = val2;
157 			break;
158 		}
159 	}
160 
161 	return ret;
162 }
163 
164 static int hdc100x_get_measurement(struct hdc100x_data *data,
165 				   struct iio_chan_spec const *chan)
166 {
167 	struct i2c_client *client = data->client;
168 	int delay = data->adc_int_us[chan->address];
169 	int ret;
170 	__be16 val;
171 
172 	/* start measurement */
173 	ret = i2c_smbus_write_byte(client, chan->address);
174 	if (ret < 0) {
175 		dev_err(&client->dev, "cannot start measurement");
176 		return ret;
177 	}
178 
179 	/* wait for integration time to pass */
180 	usleep_range(delay, delay + 1000);
181 
182 	/* read measurement */
183 	ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
184 	if (ret < 0) {
185 		dev_err(&client->dev, "cannot read sensor data\n");
186 		return ret;
187 	}
188 	return be16_to_cpu(val);
189 }
190 
191 static int hdc100x_get_heater_status(struct hdc100x_data *data)
192 {
193 	return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
194 }
195 
196 static int hdc100x_read_raw(struct iio_dev *indio_dev,
197 			    struct iio_chan_spec const *chan, int *val,
198 			    int *val2, long mask)
199 {
200 	struct hdc100x_data *data = iio_priv(indio_dev);
201 
202 	switch (mask) {
203 	case IIO_CHAN_INFO_RAW: {
204 		int ret;
205 
206 		mutex_lock(&data->lock);
207 		if (chan->type == IIO_CURRENT) {
208 			*val = hdc100x_get_heater_status(data);
209 			ret = IIO_VAL_INT;
210 		} else {
211 			ret = iio_device_claim_direct_mode(indio_dev);
212 			if (ret) {
213 				mutex_unlock(&data->lock);
214 				return ret;
215 			}
216 
217 			ret = hdc100x_get_measurement(data, chan);
218 			iio_device_release_direct_mode(indio_dev);
219 			if (ret >= 0) {
220 				*val = ret;
221 				ret = IIO_VAL_INT;
222 			}
223 		}
224 		mutex_unlock(&data->lock);
225 		return ret;
226 	}
227 	case IIO_CHAN_INFO_INT_TIME:
228 		*val = 0;
229 		*val2 = data->adc_int_us[chan->address];
230 		return IIO_VAL_INT_PLUS_MICRO;
231 	case IIO_CHAN_INFO_SCALE:
232 		if (chan->type == IIO_TEMP) {
233 			*val = 165000;
234 			*val2 = 65536;
235 			return IIO_VAL_FRACTIONAL;
236 		} else {
237 			*val = 100000;
238 			*val2 = 65536;
239 			return IIO_VAL_FRACTIONAL;
240 		}
241 		break;
242 	case IIO_CHAN_INFO_OFFSET:
243 		*val = -15887;
244 		*val2 = 515151;
245 		return IIO_VAL_INT_PLUS_MICRO;
246 	default:
247 		return -EINVAL;
248 	}
249 }
250 
251 static int hdc100x_write_raw(struct iio_dev *indio_dev,
252 			     struct iio_chan_spec const *chan,
253 			     int val, int val2, long mask)
254 {
255 	struct hdc100x_data *data = iio_priv(indio_dev);
256 	int ret = -EINVAL;
257 
258 	switch (mask) {
259 	case IIO_CHAN_INFO_INT_TIME:
260 		if (val != 0)
261 			return -EINVAL;
262 
263 		mutex_lock(&data->lock);
264 		ret = hdc100x_set_it_time(data, chan->address, val2);
265 		mutex_unlock(&data->lock);
266 		return ret;
267 	case IIO_CHAN_INFO_RAW:
268 		if (chan->type != IIO_CURRENT || val2 != 0)
269 			return -EINVAL;
270 
271 		mutex_lock(&data->lock);
272 		ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
273 					val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
274 		mutex_unlock(&data->lock);
275 		return ret;
276 	default:
277 		return -EINVAL;
278 	}
279 }
280 
281 static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
282 {
283 	struct hdc100x_data *data = iio_priv(indio_dev);
284 	int ret;
285 
286 	ret = iio_triggered_buffer_postenable(indio_dev);
287 	if (ret)
288 		return ret;
289 
290 	/* Buffer is enabled. First set ACQ Mode, then attach poll func */
291 	mutex_lock(&data->lock);
292 	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
293 				    HDC100X_REG_CONFIG_ACQ_MODE);
294 	mutex_unlock(&data->lock);
295 	if (ret)
296 		iio_triggered_buffer_predisable(indio_dev);
297 
298 	return ret;
299 }
300 
301 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
302 {
303 	struct hdc100x_data *data = iio_priv(indio_dev);
304 	int ret, ret2;
305 
306 	mutex_lock(&data->lock);
307 	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
308 	mutex_unlock(&data->lock);
309 
310 	ret2 = iio_triggered_buffer_predisable(indio_dev);
311 	if (ret == 0)
312 		ret = ret2;
313 
314 	return ret;
315 }
316 
317 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
318 	.postenable  = hdc100x_buffer_postenable,
319 	.predisable  = hdc100x_buffer_predisable,
320 };
321 
322 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
323 {
324 	struct iio_poll_func *pf = p;
325 	struct iio_dev *indio_dev = pf->indio_dev;
326 	struct hdc100x_data *data = iio_priv(indio_dev);
327 	struct i2c_client *client = data->client;
328 	int delay = data->adc_int_us[0] + data->adc_int_us[1];
329 	int ret;
330 
331 	/* dual read starts at temp register */
332 	mutex_lock(&data->lock);
333 	ret = i2c_smbus_write_byte(client, HDC100X_REG_TEMP);
334 	if (ret < 0) {
335 		dev_err(&client->dev, "cannot start measurement\n");
336 		goto err;
337 	}
338 	usleep_range(delay, delay + 1000);
339 
340 	ret = i2c_master_recv(client, (u8 *)data->scan.channels, 4);
341 	if (ret < 0) {
342 		dev_err(&client->dev, "cannot read sensor data\n");
343 		goto err;
344 	}
345 
346 	iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
347 					   iio_get_time_ns(indio_dev));
348 err:
349 	mutex_unlock(&data->lock);
350 	iio_trigger_notify_done(indio_dev->trig);
351 
352 	return IRQ_HANDLED;
353 }
354 
355 static const struct iio_info hdc100x_info = {
356 	.read_raw = hdc100x_read_raw,
357 	.write_raw = hdc100x_write_raw,
358 	.attrs = &hdc100x_attribute_group,
359 };
360 
361 static int hdc100x_probe(struct i2c_client *client,
362 			 const struct i2c_device_id *id)
363 {
364 	struct iio_dev *indio_dev;
365 	struct hdc100x_data *data;
366 	int ret;
367 
368 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
369 				     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
370 		return -EOPNOTSUPP;
371 
372 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
373 	if (!indio_dev)
374 		return -ENOMEM;
375 
376 	data = iio_priv(indio_dev);
377 	i2c_set_clientdata(client, indio_dev);
378 	data->client = client;
379 	mutex_init(&data->lock);
380 
381 	indio_dev->dev.parent = &client->dev;
382 	indio_dev->name = dev_name(&client->dev);
383 	indio_dev->modes = INDIO_DIRECT_MODE;
384 	indio_dev->info = &hdc100x_info;
385 
386 	indio_dev->channels = hdc100x_channels;
387 	indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
388 	indio_dev->available_scan_masks = hdc100x_scan_masks;
389 
390 	/* be sure we are in a known state */
391 	hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
392 	hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
393 	hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
394 
395 	ret = devm_iio_triggered_buffer_setup(&client->dev,
396 					 indio_dev, NULL,
397 					 hdc100x_trigger_handler,
398 					 &hdc_buffer_setup_ops);
399 	if (ret < 0) {
400 		dev_err(&client->dev, "iio triggered buffer setup failed\n");
401 		return ret;
402 	}
403 
404 	return devm_iio_device_register(&client->dev, indio_dev);
405 }
406 
407 static const struct i2c_device_id hdc100x_id[] = {
408 	{ "hdc100x", 0 },
409 	{ "hdc1000", 0 },
410 	{ "hdc1008", 0 },
411 	{ "hdc1010", 0 },
412 	{ "hdc1050", 0 },
413 	{ "hdc1080", 0 },
414 	{ }
415 };
416 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
417 
418 static const struct of_device_id hdc100x_dt_ids[] = {
419 	{ .compatible = "ti,hdc1000" },
420 	{ .compatible = "ti,hdc1008" },
421 	{ .compatible = "ti,hdc1010" },
422 	{ .compatible = "ti,hdc1050" },
423 	{ .compatible = "ti,hdc1080" },
424 	{ }
425 };
426 MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
427 
428 static struct i2c_driver hdc100x_driver = {
429 	.driver = {
430 		.name	= "hdc100x",
431 		.of_match_table = of_match_ptr(hdc100x_dt_ids),
432 	},
433 	.probe = hdc100x_probe,
434 	.id_table = hdc100x_id,
435 };
436 module_i2c_driver(hdc100x_driver);
437 
438 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
439 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
440 MODULE_LICENSE("GPL");
441