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  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
 37struct 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 */
 52static 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 */
 58static 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
 72static IIO_CONST_ATTR(temp_integration_time_available,
 73		"0.00365 0.00635");
 74
 75static IIO_CONST_ATTR(humidityrelative_integration_time_available,
 76		"0.0025 0.00385 0.0065");
 77
 78static IIO_CONST_ATTR(out_current_heater_raw_available,
 79		"0 1");
 80
 81static 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
 88static const struct attribute_group hdc100x_attribute_group = {
 89	.attrs = hdc100x_attributes,
 90};
 91
 92static 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
132static const unsigned long hdc100x_scan_masks[] = {0x3, 0};
133
134static 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
147static 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
167static 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
194static int hdc100x_get_heater_status(struct hdc100x_data *data)
195{
196	return !!(data->config & HDC100X_REG_CONFIG_HEATER_EN);
197}
198
199static 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
254static 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
284static 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
298static 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
310static const struct iio_buffer_setup_ops hdc_buffer_setup_ops = {
311	.postenable  = hdc100x_buffer_postenable,
312	.predisable  = hdc100x_buffer_predisable,
313};
314
315static 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));
341err:
342	mutex_unlock(&data->lock);
343	iio_trigger_notify_done(indio_dev->trig);
344
345	return IRQ_HANDLED;
346}
347
348static 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
354static int hdc100x_probe(struct i2c_client *client)
355{
356	struct iio_dev *indio_dev;
357	struct hdc100x_data *data;
358	int ret;
359
360	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WORD_DATA |
361				     I2C_FUNC_SMBUS_BYTE | I2C_FUNC_I2C))
362		return -EOPNOTSUPP;
363
364	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
365	if (!indio_dev)
366		return -ENOMEM;
367
368	data = iio_priv(indio_dev);
369	i2c_set_clientdata(client, indio_dev);
370	data->client = client;
371	mutex_init(&data->lock);
372
373	indio_dev->name = dev_name(&client->dev);
374	indio_dev->modes = INDIO_DIRECT_MODE;
375	indio_dev->info = &hdc100x_info;
376
377	indio_dev->channels = hdc100x_channels;
378	indio_dev->num_channels = ARRAY_SIZE(hdc100x_channels);
379	indio_dev->available_scan_masks = hdc100x_scan_masks;
380
381	/* be sure we are in a known state */
382	hdc100x_set_it_time(data, 0, hdc100x_int_time[0][0]);
383	hdc100x_set_it_time(data, 1, hdc100x_int_time[1][0]);
384	hdc100x_update_config(data, HDC100X_REG_CONFIG_ACQ_MODE, 0);
385
386	ret = devm_iio_triggered_buffer_setup(&client->dev,
387					 indio_dev, NULL,
388					 hdc100x_trigger_handler,
389					 &hdc_buffer_setup_ops);
390	if (ret < 0) {
391		dev_err(&client->dev, "iio triggered buffer setup failed\n");
392		return ret;
393	}
394
395	return devm_iio_device_register(&client->dev, indio_dev);
396}
397
398static const struct i2c_device_id hdc100x_id[] = {
399	{ "hdc100x" },
400	{ "hdc1000" },
401	{ "hdc1008" },
402	{ "hdc1010" },
403	{ "hdc1050" },
404	{ "hdc1080" },
405	{ }
406};
407MODULE_DEVICE_TABLE(i2c, hdc100x_id);
408
409static const struct of_device_id hdc100x_dt_ids[] = {
410	{ .compatible = "ti,hdc1000" },
411	{ .compatible = "ti,hdc1008" },
412	{ .compatible = "ti,hdc1010" },
413	{ .compatible = "ti,hdc1050" },
414	{ .compatible = "ti,hdc1080" },
415	{ }
416};
417MODULE_DEVICE_TABLE(of, hdc100x_dt_ids);
418
419static const struct acpi_device_id hdc100x_acpi_match[] = {
420	{ "TXNW1010" },
421	{ }
422};
423MODULE_DEVICE_TABLE(acpi, hdc100x_acpi_match);
424
425static struct i2c_driver hdc100x_driver = {
426	.driver = {
427		.name	= "hdc100x",
428		.of_match_table = hdc100x_dt_ids,
429		.acpi_match_table = hdc100x_acpi_match,
430	},
431	.probe = hdc100x_probe,
432	.id_table = hdc100x_id,
433};
434module_i2c_driver(hdc100x_driver);
435
436MODULE_AUTHOR("Matt Ranostay <matt.ranostay@konsulko.com>");
437MODULE_DESCRIPTION("TI HDC100x humidity and temperature sensor driver");
438MODULE_LICENSE("GPL");