xref: /openbmc/linux/drivers/iio/humidity/hdc100x.c (revision 2326f3cd)
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  * https://www.ti.com/product/HDC1000/datasheet
10  * https://www.ti.com/product/HDC1008/datasheet
11  * https://www.ti.com/product/HDC1010/datasheet
12  * https://www.ti.com/product/HDC1050/datasheet
13  * https://www.ti.com/product/HDC1080/datasheet
14  */
15 
16 #include <linux/delay.h>
17 #include <linux/module.h>
18 #include <linux/mod_devicetable.h>
19 #include <linux/init.h>
20 #include <linux/i2c.h>
21 
22 #include <linux/iio/iio.h>
23 #include <linux/iio/sysfs.h>
24 #include <linux/iio/buffer.h>
25 #include <linux/iio/trigger_consumer.h>
26 #include <linux/iio/triggered_buffer.h>
27 
28 #include <linux/time.h>
29 
30 #define HDC100X_REG_TEMP			0x00
31 #define HDC100X_REG_HUMIDITY			0x01
32 
33 #define HDC100X_REG_CONFIG			0x02
34 #define HDC100X_REG_CONFIG_ACQ_MODE		BIT(12)
35 #define HDC100X_REG_CONFIG_HEATER_EN		BIT(13)
36 
37 struct hdc100x_data {
38 	struct i2c_client *client;
39 	struct mutex lock;
40 	u16 config;
41 
42 	/* integration time of the sensor */
43 	int adc_int_us[2];
44 	/* Ensure natural alignment of timestamp */
45 	struct {
46 		__be16 channels[2];
47 		s64 ts __aligned(8);
48 	} scan;
49 };
50 
51 /* integration time in us */
52 static const int hdc100x_int_time[][3] = {
53 	{ 6350, 3650, 0 },	/* IIO_TEMP channel*/
54 	{ 6500, 3850, 2500 },	/* IIO_HUMIDITYRELATIVE channel */
55 };
56 
57 /* HDC100X_REG_CONFIG shift and mask values */
58 static const struct {
59 	int shift;
60 	int mask;
61 } hdc100x_resolution_shift[2] = {
62 	{ /* IIO_TEMP channel */
63 		.shift = 10,
64 		.mask = 1
65 	},
66 	{ /* IIO_HUMIDITYRELATIVE channel */
67 		.shift = 8,
68 		.mask = 3,
69 	},
70 };
71 
72 static IIO_CONST_ATTR(temp_integration_time_available,
73 		"0.00365 0.00635");
74 
75 static IIO_CONST_ATTR(humidityrelative_integration_time_available,
76 		"0.0025 0.00385 0.0065");
77 
78 static IIO_CONST_ATTR(out_current_heater_raw_available,
79 		"0 1");
80 
81 static struct attribute *hdc100x_attributes[] = {
82 	&iio_const_attr_temp_integration_time_available.dev_attr.attr,
83 	&iio_const_attr_humidityrelative_integration_time_available.dev_attr.attr,
84 	&iio_const_attr_out_current_heater_raw_available.dev_attr.attr,
85 	NULL
86 };
87 
88 static const struct attribute_group hdc100x_attribute_group = {
89 	.attrs = hdc100x_attributes,
90 };
91 
92 static const struct iio_chan_spec hdc100x_channels[] = {
93 	{
94 		.type = IIO_TEMP,
95 		.address = HDC100X_REG_TEMP,
96 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
97 			BIT(IIO_CHAN_INFO_SCALE) |
98 			BIT(IIO_CHAN_INFO_INT_TIME) |
99 			BIT(IIO_CHAN_INFO_OFFSET),
100 		.scan_index = 0,
101 		.scan_type = {
102 			.sign = 's',
103 			.realbits = 16,
104 			.storagebits = 16,
105 			.endianness = IIO_BE,
106 		},
107 	},
108 	{
109 		.type = IIO_HUMIDITYRELATIVE,
110 		.address = HDC100X_REG_HUMIDITY,
111 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
112 			BIT(IIO_CHAN_INFO_SCALE) |
113 			BIT(IIO_CHAN_INFO_INT_TIME),
114 		.scan_index = 1,
115 		.scan_type = {
116 			.sign = 'u',
117 			.realbits = 16,
118 			.storagebits = 16,
119 			.endianness = IIO_BE,
120 		},
121 	},
122 	{
123 		.type = IIO_CURRENT,
124 		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
125 		.extend_name = "heater",
126 		.output = 1,
127 		.scan_index = -1,
128 	},
129 	IIO_CHAN_SOFT_TIMESTAMP(2),
130 };
131 
132 static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
133 
134 static int hdc100x_update_config(struct hdc100x_data *data, int mask, int val)
135 {
136 	int tmp = (~mask & data->config) | val;
137 	int ret;
138 
139 	ret = i2c_smbus_write_word_swapped(data->client,
140 						HDC100X_REG_CONFIG, tmp);
141 	if (!ret)
142 		data->config = tmp;
143 
144 	return ret;
145 }
146 
147 static int hdc100x_set_it_time(struct hdc100x_data *data, int chan, int val2)
148 {
149 	int shift = hdc100x_resolution_shift[chan].shift;
150 	int ret = -EINVAL;
151 	int i;
152 
153 	for (i = 0; i < ARRAY_SIZE(hdc100x_int_time[chan]); i++) {
154 		if (val2 && val2 == hdc100x_int_time[chan][i]) {
155 			ret = hdc100x_update_config(data,
156 				hdc100x_resolution_shift[chan].mask << shift,
157 				i << shift);
158 			if (!ret)
159 				data->adc_int_us[chan] = val2;
160 			break;
161 		}
162 	}
163 
164 	return ret;
165 }
166 
167 static int hdc100x_get_measurement(struct hdc100x_data *data,
168 				   struct iio_chan_spec const *chan)
169 {
170 	struct i2c_client *client = data->client;
171 	int delay = data->adc_int_us[chan->address] + 1*USEC_PER_MSEC;
172 	int ret;
173 	__be16 val;
174 
175 	/* start measurement */
176 	ret = i2c_smbus_write_byte(client, chan->address);
177 	if (ret < 0) {
178 		dev_err(&client->dev, "cannot start measurement");
179 		return ret;
180 	}
181 
182 	/* wait for integration time to pass */
183 	usleep_range(delay, delay + 1000);
184 
185 	/* read measurement */
186 	ret = i2c_master_recv(data->client, (char *)&val, sizeof(val));
187 	if (ret < 0) {
188 		dev_err(&client->dev, "cannot read sensor data\n");
189 		return ret;
190 	}
191 	return be16_to_cpu(val);
192 }
193 
194 static int hdc100x_get_heater_status(struct hdc100x_data *data)
195 {
196 	return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
197 }
198 
199 static int hdc100x_read_raw(struct iio_dev *indio_dev,
200 			    struct iio_chan_spec const *chan, int *val,
201 			    int *val2, long mask)
202 {
203 	struct hdc100x_data *data = iio_priv(indio_dev);
204 
205 	switch (mask) {
206 	case IIO_CHAN_INFO_RAW: {
207 		int ret;
208 
209 		mutex_lock(&data->lock);
210 		if (chan->type == IIO_CURRENT) {
211 			*val = hdc100x_get_heater_status(data);
212 			ret = IIO_VAL_INT;
213 		} else {
214 			ret = iio_device_claim_direct_mode(indio_dev);
215 			if (ret) {
216 				mutex_unlock(&data->lock);
217 				return ret;
218 			}
219 
220 			ret = hdc100x_get_measurement(data, chan);
221 			iio_device_release_direct_mode(indio_dev);
222 			if (ret >= 0) {
223 				*val = ret;
224 				ret = IIO_VAL_INT;
225 			}
226 		}
227 		mutex_unlock(&data->lock);
228 		return ret;
229 	}
230 	case IIO_CHAN_INFO_INT_TIME:
231 		*val = 0;
232 		*val2 = data->adc_int_us[chan->address];
233 		return IIO_VAL_INT_PLUS_MICRO;
234 	case IIO_CHAN_INFO_SCALE:
235 		if (chan->type == IIO_TEMP) {
236 			*val = 165000;
237 			*val2 = 65536;
238 			return IIO_VAL_FRACTIONAL;
239 		} else {
240 			*val = 100000;
241 			*val2 = 65536;
242 			return IIO_VAL_FRACTIONAL;
243 		}
244 		break;
245 	case IIO_CHAN_INFO_OFFSET:
246 		*val = -15887;
247 		*val2 = 515151;
248 		return IIO_VAL_INT_PLUS_MICRO;
249 	default:
250 		return -EINVAL;
251 	}
252 }
253 
254 static int hdc100x_write_raw(struct iio_dev *indio_dev,
255 			     struct iio_chan_spec const *chan,
256 			     int val, int val2, long mask)
257 {
258 	struct hdc100x_data *data = iio_priv(indio_dev);
259 	int ret = -EINVAL;
260 
261 	switch (mask) {
262 	case IIO_CHAN_INFO_INT_TIME:
263 		if (val != 0)
264 			return -EINVAL;
265 
266 		mutex_lock(&data->lock);
267 		ret = hdc100x_set_it_time(data, chan->address, val2);
268 		mutex_unlock(&data->lock);
269 		return ret;
270 	case IIO_CHAN_INFO_RAW:
271 		if (chan->type != IIO_CURRENT || val2 != 0)
272 			return -EINVAL;
273 
274 		mutex_lock(&data->lock);
275 		ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_HEATER_EN,
276 					val ? HDC100X_REG_CONFIG_HEATER_EN : 0);
277 		mutex_unlock(&data->lock);
278 		return ret;
279 	default:
280 		return -EINVAL;
281 	}
282 }
283 
284 static int hdc100x_buffer_postenable(struct iio_dev *indio_dev)
285 {
286 	struct hdc100x_data *data = iio_priv(indio_dev);
287 	int ret;
288 
289 	/* Buffer is enabled. First set ACQ Mode, then attach poll func */
290 	mutex_lock(&data->lock);
291 	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE,
292 				    HDC100X_REG_CONFIG_ACQ_MODE);
293 	mutex_unlock(&data->lock);
294 
295 	return ret;
296 }
297 
298 static int hdc100x_buffer_predisable(struct iio_dev *indio_dev)
299 {
300 	struct hdc100x_data *data = iio_priv(indio_dev);
301 	int ret;
302 
303 	mutex_lock(&data->lock);
304 	ret = hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
305 	mutex_unlock(&data->lock);
306 
307 	return ret;
308 }
309 
310 static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
311 	.postenable  = hdc100x_buffer_postenable,
312 	.predisable  = hdc100x_buffer_predisable,
313 };
314 
315 static irqreturn_t hdc100x_trigger_handler(int irq, void *p)
316 {
317 	struct iio_poll_func *pf = p;
318 	struct iio_dev *indio_dev = pf->indio_dev;
319 	struct hdc100x_data *data = iio_priv(indio_dev);
320 	struct i2c_client *client = data->client;
321 	int delay = data->adc_int_us[0] + data->adc_int_us[1] + 2*USEC_PER_MSEC;
322 	int ret;
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 *)data->scan.channels, 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, &data->scan,
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->name = dev_name(&client->dev);
375 	indio_dev->modes = INDIO_DIRECT_MODE;
376 	indio_dev->info = &hdc100x_info;
377 
378 	indio_dev->channels = hdc100x_channels;
379 	indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
380 	indio_dev->available_scan_masks = hdc100x_scan_masks;
381 
382 	/* be sure we are in a known state */
383 	hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
384 	hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
385 	hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
386 
387 	ret = devm_iio_triggered_buffer_setup(&client->dev,
388 					 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 
396 	return devm_iio_device_register(&client->dev, indio_dev);
397 }
398 
399 static const struct i2c_device_id hdc100x_id[] = {
400 	{ "hdc100x", 0 },
401 	{ "hdc1000", 0 },
402 	{ "hdc1008", 0 },
403 	{ "hdc1010", 0 },
404 	{ "hdc1050", 0 },
405 	{ "hdc1080", 0 },
406 	{ }
407 };
408 MODULE_DEVICE_TABLE(i2c, hdc100x_id);
409 
410 static const struct of_device_id hdc100x_dt_ids[] = {
411 	{ .compatible = "ti,hdc1000" },
412 	{ .compatible = "ti,hdc1008" },
413 	{ .compatible = "ti,hdc1010" },
414 	{ .compatible = "ti,hdc1050" },
415 	{ .compatible = "ti,hdc1080" },
416 	{ }
417 };
418 MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
419 
420 static struct i2c_driver hdc100x_driver = {
421 	.driver = {
422 		.name	= "hdc100x",
423 		.of_match_table = hdc100x_dt_ids,
424 	},
425 	.probe = hdc100x_probe,
426 	.id_table = hdc100x_id,
427 };
428 module_i2c_driver(hdc100x_driver);
429 
430 MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
431 MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
432 MODULE_LICENSE("GPL");
433