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1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Sensirion SHT3x-DIS humidity and temperature sensor driver.
3 * The SHT3x comes in many different versions, this driver is for the
4 * I2C version only.
5 *
6 * Copyright (C) 2016 Sensirion AG, Switzerland
7 * Author: David Frey <david.frey@sensirion.com>
8 * Author: Pascal Sachs <pascal.sachs@sensirion.com>
9 */
10
11#include <asm/page.h>
12#include <linux/crc8.h>
13#include <linux/delay.h>
14#include <linux/err.h>
15#include <linux/hwmon.h>
16#include <linux/hwmon-sysfs.h>
17#include <linux/i2c.h>
18#include <linux/init.h>
19#include <linux/kernel.h>
20#include <linux/module.h>
21#include <linux/slab.h>
22#include <linux/jiffies.h>
23
24/* commands (high repeatability mode) */
25static const unsigned char sht3x_cmd_measure_single_hpm[] = { 0x24, 0x00 };
26
27/* commands (medium repeatability mode) */
28static const unsigned char sht3x_cmd_measure_single_mpm[] = { 0x24, 0x0b };
29
30/* commands (low repeatability mode) */
31static const unsigned char sht3x_cmd_measure_single_lpm[] = { 0x24, 0x16 };
32
33/* commands for periodic mode */
34static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 };
35static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 };
36
37/* commands for heater control */
38static const unsigned char sht3x_cmd_heater_on[] = { 0x30, 0x6d };
39static const unsigned char sht3x_cmd_heater_off[] = { 0x30, 0x66 };
40
41/* other commands */
42static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d };
43static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 };
44
45/* delays for single-shot mode i2c commands, both in us */
46#define SHT3X_SINGLE_WAIT_TIME_HPM 15000
47#define SHT3X_SINGLE_WAIT_TIME_MPM 6000
48#define SHT3X_SINGLE_WAIT_TIME_LPM 4000
49
50#define SHT3X_WORD_LEN 2
51#define SHT3X_CMD_LENGTH 2
52#define SHT3X_CRC8_LEN 1
53#define SHT3X_RESPONSE_LENGTH 6
54#define SHT3X_CRC8_POLYNOMIAL 0x31
55#define SHT3X_CRC8_INIT 0xFF
56#define SHT3X_MIN_TEMPERATURE -45000
57#define SHT3X_MAX_TEMPERATURE 130000
58#define SHT3X_MIN_HUMIDITY 0
59#define SHT3X_MAX_HUMIDITY 100000
60
61enum sht3x_chips {
62 sht3x,
63 sts3x,
64};
65
66enum sht3x_limits {
67 limit_max = 0,
68 limit_max_hyst,
69 limit_min,
70 limit_min_hyst,
71};
72
73enum sht3x_repeatability {
74 low_repeatability,
75 medium_repeatability,
76 high_repeatability,
77};
78
79DECLARE_CRC8_TABLE(sht3x_crc8_table);
80
81/* periodic measure commands (high repeatability mode) */
82static const char periodic_measure_commands_hpm[][SHT3X_CMD_LENGTH] = {
83 /* 0.5 measurements per second */
84 {0x20, 0x32},
85 /* 1 measurements per second */
86 {0x21, 0x30},
87 /* 2 measurements per second */
88 {0x22, 0x36},
89 /* 4 measurements per second */
90 {0x23, 0x34},
91 /* 10 measurements per second */
92 {0x27, 0x37},
93};
94
95/* periodic measure commands (medium repeatability) */
96static const char periodic_measure_commands_mpm[][SHT3X_CMD_LENGTH] = {
97 /* 0.5 measurements per second */
98 {0x20, 0x24},
99 /* 1 measurements per second */
100 {0x21, 0x26},
101 /* 2 measurements per second */
102 {0x22, 0x20},
103 /* 4 measurements per second */
104 {0x23, 0x22},
105 /* 10 measurements per second */
106 {0x27, 0x21},
107};
108
109/* periodic measure commands (low repeatability mode) */
110static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = {
111 /* 0.5 measurements per second */
112 {0x20, 0x2f},
113 /* 1 measurements per second */
114 {0x21, 0x2d},
115 /* 2 measurements per second */
116 {0x22, 0x2b},
117 /* 4 measurements per second */
118 {0x23, 0x29},
119 /* 10 measurements per second */
120 {0x27, 0x2a},
121};
122
123struct sht3x_limit_commands {
124 const char read_command[SHT3X_CMD_LENGTH];
125 const char write_command[SHT3X_CMD_LENGTH];
126};
127
128static const struct sht3x_limit_commands limit_commands[] = {
129 /* temp1_max, humidity1_max */
130 [limit_max] = { {0xe1, 0x1f}, {0x61, 0x1d} },
131 /* temp_1_max_hyst, humidity1_max_hyst */
132 [limit_max_hyst] = { {0xe1, 0x14}, {0x61, 0x16} },
133 /* temp1_min, humidity1_min */
134 [limit_min] = { {0xe1, 0x02}, {0x61, 0x00} },
135 /* temp_1_min_hyst, humidity1_min_hyst */
136 [limit_min_hyst] = { {0xe1, 0x09}, {0x61, 0x0B} },
137};
138
139#define SHT3X_NUM_LIMIT_CMD ARRAY_SIZE(limit_commands)
140
141static const u16 mode_to_update_interval[] = {
142 0,
143 2000,
144 1000,
145 500,
146 250,
147 100,
148};
149
150static const struct hwmon_channel_info * const sht3x_channel_info[] = {
151 HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
152 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN |
153 HWMON_T_MIN_HYST | HWMON_T_MAX |
154 HWMON_T_MAX_HYST | HWMON_T_ALARM),
155 HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN |
156 HWMON_H_MIN_HYST | HWMON_H_MAX |
157 HWMON_H_MAX_HYST | HWMON_H_ALARM),
158 NULL,
159};
160
161struct sht3x_data {
162 struct i2c_client *client;
163 enum sht3x_chips chip_id;
164 struct mutex i2c_lock; /* lock for sending i2c commands */
165 struct mutex data_lock; /* lock for updating driver data */
166
167 u8 mode;
168 const unsigned char *command;
169 u32 wait_time; /* in us*/
170 unsigned long last_update; /* last update in periodic mode*/
171 enum sht3x_repeatability repeatability;
172
173 /*
174 * cached values for temperature and humidity and limits
175 * the limits arrays have the following order:
176 * max, max_hyst, min, min_hyst
177 */
178 int temperature;
179 int temperature_limits[SHT3X_NUM_LIMIT_CMD];
180 u32 humidity;
181 u32 humidity_limits[SHT3X_NUM_LIMIT_CMD];
182};
183
184static u8 get_mode_from_update_interval(u16 value)
185{
186 size_t index;
187 u8 number_of_modes = ARRAY_SIZE(mode_to_update_interval);
188
189 if (value == 0)
190 return 0;
191
192 /* find next faster update interval */
193 for (index = 1; index < number_of_modes; index++) {
194 if (mode_to_update_interval[index] <= value)
195 return index;
196 }
197
198 return number_of_modes - 1;
199}
200
201static int sht3x_read_from_command(struct i2c_client *client,
202 struct sht3x_data *data,
203 const char *command,
204 char *buf, int length, u32 wait_time)
205{
206 int ret;
207
208 mutex_lock(&data->i2c_lock);
209 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
210
211 if (ret != SHT3X_CMD_LENGTH) {
212 ret = ret < 0 ? ret : -EIO;
213 goto out;
214 }
215
216 if (wait_time)
217 usleep_range(wait_time, wait_time + 1000);
218
219 ret = i2c_master_recv(client, buf, length);
220 if (ret != length) {
221 ret = ret < 0 ? ret : -EIO;
222 goto out;
223 }
224
225 ret = 0;
226out:
227 mutex_unlock(&data->i2c_lock);
228 return ret;
229}
230
231static int sht3x_extract_temperature(u16 raw)
232{
233 /*
234 * From datasheet:
235 * T = -45 + 175 * ST / 2^16
236 * Adapted for integer fixed point (3 digit) arithmetic.
237 */
238 return ((21875 * (int)raw) >> 13) - 45000;
239}
240
241static u32 sht3x_extract_humidity(u16 raw)
242{
243 /*
244 * From datasheet:
245 * RH = 100 * SRH / 2^16
246 * Adapted for integer fixed point (3 digit) arithmetic.
247 */
248 return (12500 * (u32)raw) >> 13;
249}
250
251static struct sht3x_data *sht3x_update_client(struct device *dev)
252{
253 struct sht3x_data *data = dev_get_drvdata(dev);
254 struct i2c_client *client = data->client;
255 u16 interval_ms = mode_to_update_interval[data->mode];
256 unsigned long interval_jiffies = msecs_to_jiffies(interval_ms);
257 unsigned char buf[SHT3X_RESPONSE_LENGTH];
258 u16 val;
259 int ret = 0;
260
261 mutex_lock(&data->data_lock);
262 /*
263 * Only update cached readings once per update interval in periodic
264 * mode. In single shot mode the sensor measures values on demand, so
265 * every time the sysfs interface is called, a measurement is triggered.
266 * In periodic mode however, the measurement process is handled
267 * internally by the sensor and reading out sensor values only makes
268 * sense if a new reading is available.
269 */
270 if (time_after(jiffies, data->last_update + interval_jiffies)) {
271 ret = sht3x_read_from_command(client, data, data->command, buf,
272 sizeof(buf), data->wait_time);
273 if (ret)
274 goto out;
275
276 val = be16_to_cpup((__be16 *)buf);
277 data->temperature = sht3x_extract_temperature(val);
278 val = be16_to_cpup((__be16 *)(buf + 3));
279 data->humidity = sht3x_extract_humidity(val);
280 data->last_update = jiffies;
281 }
282
283out:
284 mutex_unlock(&data->data_lock);
285 if (ret)
286 return ERR_PTR(ret);
287
288 return data;
289}
290
291static int temp1_input_read(struct device *dev)
292{
293 struct sht3x_data *data = sht3x_update_client(dev);
294
295 if (IS_ERR(data))
296 return PTR_ERR(data);
297
298 return data->temperature;
299}
300
301static int humidity1_input_read(struct device *dev)
302{
303 struct sht3x_data *data = sht3x_update_client(dev);
304
305 if (IS_ERR(data))
306 return PTR_ERR(data);
307
308 return data->humidity;
309}
310
311/*
312 * limits_update must only be called from probe or with data_lock held
313 */
314static int limits_update(struct sht3x_data *data)
315{
316 int ret;
317 u8 index;
318 int temperature;
319 u32 humidity;
320 u16 raw;
321 char buffer[SHT3X_RESPONSE_LENGTH];
322 const struct sht3x_limit_commands *commands;
323 struct i2c_client *client = data->client;
324
325 for (index = 0; index < SHT3X_NUM_LIMIT_CMD; index++) {
326 commands = &limit_commands[index];
327 ret = sht3x_read_from_command(client, data,
328 commands->read_command, buffer,
329 SHT3X_RESPONSE_LENGTH, 0);
330
331 if (ret)
332 return ret;
333
334 raw = be16_to_cpup((__be16 *)buffer);
335 temperature = sht3x_extract_temperature((raw & 0x01ff) << 7);
336 humidity = sht3x_extract_humidity(raw & 0xfe00);
337 data->temperature_limits[index] = temperature;
338 data->humidity_limits[index] = humidity;
339 }
340
341 return ret;
342}
343
344static int temp1_limit_read(struct device *dev, int index)
345{
346 struct sht3x_data *data = dev_get_drvdata(dev);
347
348 return data->temperature_limits[index];
349}
350
351static int humidity1_limit_read(struct device *dev, int index)
352{
353 struct sht3x_data *data = dev_get_drvdata(dev);
354
355 return data->humidity_limits[index];
356}
357
358/*
359 * limit_write must only be called with data_lock held
360 */
361static size_t limit_write(struct device *dev,
362 u8 index,
363 int temperature,
364 u32 humidity)
365{
366 char buffer[SHT3X_CMD_LENGTH + SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
367 char *position = buffer;
368 int ret;
369 u16 raw;
370 struct sht3x_data *data = dev_get_drvdata(dev);
371 struct i2c_client *client = data->client;
372 const struct sht3x_limit_commands *commands;
373
374 commands = &limit_commands[index];
375
376 memcpy(position, commands->write_command, SHT3X_CMD_LENGTH);
377 position += SHT3X_CMD_LENGTH;
378 /*
379 * ST = (T + 45) / 175 * 2^16
380 * SRH = RH / 100 * 2^16
381 * adapted for fixed point arithmetic and packed the same as
382 * in limit_read()
383 */
384 raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7);
385 raw |= ((humidity * 42950) >> 16) & 0xfe00;
386
387 *((__be16 *)position) = cpu_to_be16(raw);
388 position += SHT3X_WORD_LEN;
389 *position = crc8(sht3x_crc8_table,
390 position - SHT3X_WORD_LEN,
391 SHT3X_WORD_LEN,
392 SHT3X_CRC8_INIT);
393
394 mutex_lock(&data->i2c_lock);
395 ret = i2c_master_send(client, buffer, sizeof(buffer));
396 mutex_unlock(&data->i2c_lock);
397
398 if (ret != sizeof(buffer))
399 return ret < 0 ? ret : -EIO;
400
401 data->temperature_limits[index] = temperature;
402 data->humidity_limits[index] = humidity;
403
404 return 0;
405}
406
407static int temp1_limit_write(struct device *dev, int index, int val)
408{
409 int temperature;
410 int ret;
411 struct sht3x_data *data = dev_get_drvdata(dev);
412
413 temperature = clamp_val(val, SHT3X_MIN_TEMPERATURE,
414 SHT3X_MAX_TEMPERATURE);
415 mutex_lock(&data->data_lock);
416 ret = limit_write(dev, index, temperature,
417 data->humidity_limits[index]);
418 mutex_unlock(&data->data_lock);
419
420 return ret;
421}
422
423static int humidity1_limit_write(struct device *dev, int index, int val)
424{
425 u32 humidity;
426 int ret;
427 struct sht3x_data *data = dev_get_drvdata(dev);
428
429 humidity = clamp_val(val, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY);
430 mutex_lock(&data->data_lock);
431 ret = limit_write(dev, index, data->temperature_limits[index],
432 humidity);
433 mutex_unlock(&data->data_lock);
434
435 return ret;
436}
437
438static void sht3x_select_command(struct sht3x_data *data)
439{
440 /*
441 * For single-shot mode, only non blocking mode is support,
442 * we have to wait ourselves for result.
443 */
444 if (data->mode > 0) {
445 data->command = sht3x_cmd_measure_periodic_mode;
446 data->wait_time = 0;
447 } else {
448 if (data->repeatability == high_repeatability) {
449 data->command = sht3x_cmd_measure_single_hpm;
450 data->wait_time = SHT3X_SINGLE_WAIT_TIME_HPM;
451 } else if (data->repeatability == medium_repeatability) {
452 data->command = sht3x_cmd_measure_single_mpm;
453 data->wait_time = SHT3X_SINGLE_WAIT_TIME_MPM;
454 } else {
455 data->command = sht3x_cmd_measure_single_lpm;
456 data->wait_time = SHT3X_SINGLE_WAIT_TIME_LPM;
457 }
458 }
459}
460
461static int status_register_read(struct device *dev,
462 char *buffer, int length)
463{
464 int ret;
465 struct sht3x_data *data = dev_get_drvdata(dev);
466 struct i2c_client *client = data->client;
467
468 ret = sht3x_read_from_command(client, data, sht3x_cmd_read_status_reg,
469 buffer, length, 0);
470
471 return ret;
472}
473
474static int temp1_alarm_read(struct device *dev)
475{
476 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
477 int ret;
478
479 ret = status_register_read(dev, buffer,
480 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
481 if (ret)
482 return ret;
483
484 return !!(buffer[0] & 0x04);
485}
486
487static int humidity1_alarm_read(struct device *dev)
488{
489 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
490 int ret;
491
492 ret = status_register_read(dev, buffer,
493 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
494 if (ret)
495 return ret;
496
497 return !!(buffer[0] & 0x08);
498}
499
500static ssize_t heater_enable_show(struct device *dev,
501 struct device_attribute *attr,
502 char *buf)
503{
504 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
505 int ret;
506
507 ret = status_register_read(dev, buffer,
508 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
509 if (ret)
510 return ret;
511
512 return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x20));
513}
514
515static ssize_t heater_enable_store(struct device *dev,
516 struct device_attribute *attr,
517 const char *buf,
518 size_t count)
519{
520 struct sht3x_data *data = dev_get_drvdata(dev);
521 struct i2c_client *client = data->client;
522 int ret;
523 bool status;
524
525 ret = kstrtobool(buf, &status);
526 if (ret)
527 return ret;
528
529 mutex_lock(&data->i2c_lock);
530
531 if (status)
532 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_on,
533 SHT3X_CMD_LENGTH);
534 else
535 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_off,
536 SHT3X_CMD_LENGTH);
537
538 mutex_unlock(&data->i2c_lock);
539
540 return ret;
541}
542
543static int update_interval_read(struct device *dev)
544{
545 struct sht3x_data *data = dev_get_drvdata(dev);
546
547 return mode_to_update_interval[data->mode];
548}
549
550static int update_interval_write(struct device *dev, int val)
551{
552 u8 mode;
553 int ret;
554 const char *command;
555 struct sht3x_data *data = dev_get_drvdata(dev);
556 struct i2c_client *client = data->client;
557
558 mode = get_mode_from_update_interval(val);
559
560 mutex_lock(&data->data_lock);
561 /* mode did not change */
562 if (mode == data->mode) {
563 mutex_unlock(&data->data_lock);
564 return 0;
565 }
566
567 mutex_lock(&data->i2c_lock);
568 /*
569 * Abort periodic measure mode.
570 * To do any changes to the configuration while in periodic mode, we
571 * have to send a break command to the sensor, which then falls back
572 * to single shot (mode = 0).
573 */
574 if (data->mode > 0) {
575 ret = i2c_master_send(client, sht3x_cmd_break,
576 SHT3X_CMD_LENGTH);
577 if (ret != SHT3X_CMD_LENGTH)
578 goto out;
579 data->mode = 0;
580 }
581
582 if (mode > 0) {
583 if (data->repeatability == high_repeatability)
584 command = periodic_measure_commands_hpm[mode - 1];
585 else if (data->repeatability == medium_repeatability)
586 command = periodic_measure_commands_mpm[mode - 1];
587 else
588 command = periodic_measure_commands_lpm[mode - 1];
589
590 /* select mode */
591 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
592 if (ret != SHT3X_CMD_LENGTH)
593 goto out;
594 }
595
596 /* select mode and command */
597 data->mode = mode;
598 sht3x_select_command(data);
599
600out:
601 mutex_unlock(&data->i2c_lock);
602 mutex_unlock(&data->data_lock);
603 if (ret != SHT3X_CMD_LENGTH)
604 return ret < 0 ? ret : -EIO;
605
606 return 0;
607}
608
609static ssize_t repeatability_show(struct device *dev,
610 struct device_attribute *attr,
611 char *buf)
612{
613 struct sht3x_data *data = dev_get_drvdata(dev);
614
615 return sysfs_emit(buf, "%d\n", data->repeatability);
616}
617
618static ssize_t repeatability_store(struct device *dev,
619 struct device_attribute *attr,
620 const char *buf,
621 size_t count)
622{
623 int ret;
624 u8 val;
625
626 struct sht3x_data *data = dev_get_drvdata(dev);
627
628 ret = kstrtou8(buf, 0, &val);
629 if (ret)
630 return ret;
631
632 if (val > 2)
633 return -EINVAL;
634
635 data->repeatability = val;
636
637 return count;
638}
639
640static SENSOR_DEVICE_ATTR_RW(heater_enable, heater_enable, 0);
641static SENSOR_DEVICE_ATTR_RW(repeatability, repeatability, 0);
642
643static struct attribute *sht3x_attrs[] = {
644 &sensor_dev_attr_heater_enable.dev_attr.attr,
645 &sensor_dev_attr_repeatability.dev_attr.attr,
646 NULL
647};
648
649ATTRIBUTE_GROUPS(sht3x);
650
651static umode_t sht3x_is_visible(const void *data, enum hwmon_sensor_types type,
652 u32 attr, int channel)
653{
654 const struct sht3x_data *chip_data = data;
655
656 switch (type) {
657 case hwmon_chip:
658 switch (attr) {
659 case hwmon_chip_update_interval:
660 return 0644;
661 default:
662 break;
663 }
664 break;
665 case hwmon_temp:
666 switch (attr) {
667 case hwmon_temp_input:
668 case hwmon_temp_alarm:
669 return 0444;
670 case hwmon_temp_max:
671 case hwmon_temp_max_hyst:
672 case hwmon_temp_min:
673 case hwmon_temp_min_hyst:
674 return 0644;
675 default:
676 break;
677 }
678 break;
679 case hwmon_humidity:
680 if (chip_data->chip_id == sts3x)
681 break;
682 switch (attr) {
683 case hwmon_humidity_input:
684 case hwmon_humidity_alarm:
685 return 0444;
686 case hwmon_humidity_max:
687 case hwmon_humidity_max_hyst:
688 case hwmon_humidity_min:
689 case hwmon_humidity_min_hyst:
690 return 0644;
691 default:
692 break;
693 }
694 break;
695 default:
696 break;
697 }
698
699 return 0;
700}
701
702static int sht3x_read(struct device *dev, enum hwmon_sensor_types type,
703 u32 attr, int channel, long *val)
704{
705 enum sht3x_limits index;
706
707 switch (type) {
708 case hwmon_chip:
709 switch (attr) {
710 case hwmon_chip_update_interval:
711 *val = update_interval_read(dev);
712 break;
713 default:
714 return -EOPNOTSUPP;
715 }
716 break;
717 case hwmon_temp:
718 switch (attr) {
719 case hwmon_temp_input:
720 *val = temp1_input_read(dev);
721 break;
722 case hwmon_temp_alarm:
723 *val = temp1_alarm_read(dev);
724 break;
725 case hwmon_temp_max:
726 index = limit_max;
727 *val = temp1_limit_read(dev, index);
728 break;
729 case hwmon_temp_max_hyst:
730 index = limit_max_hyst;
731 *val = temp1_limit_read(dev, index);
732 break;
733 case hwmon_temp_min:
734 index = limit_min;
735 *val = temp1_limit_read(dev, index);
736 break;
737 case hwmon_temp_min_hyst:
738 index = limit_min_hyst;
739 *val = temp1_limit_read(dev, index);
740 break;
741 default:
742 return -EOPNOTSUPP;
743 }
744 break;
745 case hwmon_humidity:
746 switch (attr) {
747 case hwmon_humidity_input:
748 *val = humidity1_input_read(dev);
749 break;
750 case hwmon_humidity_alarm:
751 *val = humidity1_alarm_read(dev);
752 break;
753 case hwmon_humidity_max:
754 index = limit_max;
755 *val = humidity1_limit_read(dev, index);
756 break;
757 case hwmon_humidity_max_hyst:
758 index = limit_max_hyst;
759 *val = humidity1_limit_read(dev, index);
760 break;
761 case hwmon_humidity_min:
762 index = limit_min;
763 *val = humidity1_limit_read(dev, index);
764 break;
765 case hwmon_humidity_min_hyst:
766 index = limit_min_hyst;
767 *val = humidity1_limit_read(dev, index);
768 break;
769 default:
770 return -EOPNOTSUPP;
771 }
772 break;
773 default:
774 return -EOPNOTSUPP;
775 }
776
777 return 0;
778}
779
780static int sht3x_write(struct device *dev, enum hwmon_sensor_types type,
781 u32 attr, int channel, long val)
782{
783 enum sht3x_limits index;
784
785 switch (type) {
786 case hwmon_chip:
787 switch (attr) {
788 case hwmon_chip_update_interval:
789 return update_interval_write(dev, val);
790 default:
791 return -EOPNOTSUPP;
792 }
793 case hwmon_temp:
794 switch (attr) {
795 case hwmon_temp_max:
796 index = limit_max;
797 break;
798 case hwmon_temp_max_hyst:
799 index = limit_max_hyst;
800 break;
801 case hwmon_temp_min:
802 index = limit_min;
803 break;
804 case hwmon_temp_min_hyst:
805 index = limit_min_hyst;
806 break;
807 default:
808 return -EOPNOTSUPP;
809 }
810 return temp1_limit_write(dev, index, val);
811 case hwmon_humidity:
812 switch (attr) {
813 case hwmon_humidity_max:
814 index = limit_max;
815 break;
816 case hwmon_humidity_max_hyst:
817 index = limit_max_hyst;
818 break;
819 case hwmon_humidity_min:
820 index = limit_min;
821 break;
822 case hwmon_humidity_min_hyst:
823 index = limit_min_hyst;
824 break;
825 default:
826 return -EOPNOTSUPP;
827 }
828 return humidity1_limit_write(dev, index, val);
829 default:
830 return -EOPNOTSUPP;
831 }
832}
833
834static const struct hwmon_ops sht3x_ops = {
835 .is_visible = sht3x_is_visible,
836 .read = sht3x_read,
837 .write = sht3x_write,
838};
839
840static const struct hwmon_chip_info sht3x_chip_info = {
841 .ops = &sht3x_ops,
842 .info = sht3x_channel_info,
843};
844
845/* device ID table */
846static const struct i2c_device_id sht3x_ids[] = {
847 {"sht3x", sht3x},
848 {"sts3x", sts3x},
849 {}
850};
851
852MODULE_DEVICE_TABLE(i2c, sht3x_ids);
853
854static int sht3x_probe(struct i2c_client *client)
855{
856 int ret;
857 struct sht3x_data *data;
858 struct device *hwmon_dev;
859 struct i2c_adapter *adap = client->adapter;
860 struct device *dev = &client->dev;
861
862 /*
863 * we require full i2c support since the sht3x uses multi-byte read and
864 * writes as well as multi-byte commands which are not supported by
865 * the smbus protocol
866 */
867 if (!i2c_check_functionality(adap, I2C_FUNC_I2C))
868 return -ENODEV;
869
870 ret = i2c_master_send(client, sht3x_cmd_clear_status_reg,
871 SHT3X_CMD_LENGTH);
872 if (ret != SHT3X_CMD_LENGTH)
873 return ret < 0 ? ret : -ENODEV;
874
875 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
876 if (!data)
877 return -ENOMEM;
878
879 data->repeatability = high_repeatability;
880 data->mode = 0;
881 data->last_update = jiffies - msecs_to_jiffies(3000);
882 data->client = client;
883 data->chip_id = i2c_match_id(sht3x_ids, client)->driver_data;
884 crc8_populate_msb(sht3x_crc8_table, SHT3X_CRC8_POLYNOMIAL);
885
886 sht3x_select_command(data);
887
888 mutex_init(&data->i2c_lock);
889 mutex_init(&data->data_lock);
890
891 /*
892 * An attempt to read limits register too early
893 * causes a NACK response from the chip.
894 * Waiting for an empirical delay of 500 us solves the issue.
895 */
896 usleep_range(500, 600);
897
898 ret = limits_update(data);
899 if (ret)
900 return ret;
901
902 hwmon_dev = devm_hwmon_device_register_with_info(dev,
903 client->name,
904 data,
905 &sht3x_chip_info,
906 sht3x_groups);
907
908 if (IS_ERR(hwmon_dev))
909 dev_dbg(dev, "unable to register hwmon device\n");
910
911 return PTR_ERR_OR_ZERO(hwmon_dev);
912}
913
914static struct i2c_driver sht3x_i2c_driver = {
915 .driver.name = "sht3x",
916 .probe = sht3x_probe,
917 .id_table = sht3x_ids,
918};
919
920module_i2c_driver(sht3x_i2c_driver);
921
922MODULE_AUTHOR("David Frey <david.frey@sensirion.com>");
923MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>");
924MODULE_DESCRIPTION("Sensirion SHT3x humidity and temperature sensor driver");
925MODULE_LICENSE("GPL");
1/* Sensirion SHT3x-DIS humidity and temperature sensor driver.
2 * The SHT3x comes in many different versions, this driver is for the
3 * I2C version only.
4 *
5 * Copyright (C) 2016 Sensirion AG, Switzerland
6 * Author: David Frey <david.frey@sensirion.com>
7 * Author: Pascal Sachs <pascal.sachs@sensirion.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 */
20
21#include <asm/page.h>
22#include <linux/crc8.h>
23#include <linux/delay.h>
24#include <linux/err.h>
25#include <linux/hwmon.h>
26#include <linux/hwmon-sysfs.h>
27#include <linux/i2c.h>
28#include <linux/init.h>
29#include <linux/kernel.h>
30#include <linux/module.h>
31#include <linux/slab.h>
32#include <linux/jiffies.h>
33#include <linux/platform_data/sht3x.h>
34
35/* commands (high precision mode) */
36static const unsigned char sht3x_cmd_measure_blocking_hpm[] = { 0x2c, 0x06 };
37static const unsigned char sht3x_cmd_measure_nonblocking_hpm[] = { 0x24, 0x00 };
38
39/* commands (low power mode) */
40static const unsigned char sht3x_cmd_measure_blocking_lpm[] = { 0x2c, 0x10 };
41static const unsigned char sht3x_cmd_measure_nonblocking_lpm[] = { 0x24, 0x16 };
42
43/* commands for periodic mode */
44static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 };
45static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 };
46
47/* commands for heater control */
48static const unsigned char sht3x_cmd_heater_on[] = { 0x30, 0x6d };
49static const unsigned char sht3x_cmd_heater_off[] = { 0x30, 0x66 };
50
51/* other commands */
52static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d };
53static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 };
54
55/* delays for non-blocking i2c commands, both in us */
56#define SHT3X_NONBLOCKING_WAIT_TIME_HPM 15000
57#define SHT3X_NONBLOCKING_WAIT_TIME_LPM 4000
58
59#define SHT3X_WORD_LEN 2
60#define SHT3X_CMD_LENGTH 2
61#define SHT3X_CRC8_LEN 1
62#define SHT3X_RESPONSE_LENGTH 6
63#define SHT3X_CRC8_POLYNOMIAL 0x31
64#define SHT3X_CRC8_INIT 0xFF
65#define SHT3X_MIN_TEMPERATURE -45000
66#define SHT3X_MAX_TEMPERATURE 130000
67#define SHT3X_MIN_HUMIDITY 0
68#define SHT3X_MAX_HUMIDITY 100000
69
70enum sht3x_chips {
71 sht3x,
72 sts3x,
73};
74
75enum sht3x_limits {
76 limit_max = 0,
77 limit_max_hyst,
78 limit_min,
79 limit_min_hyst,
80};
81
82DECLARE_CRC8_TABLE(sht3x_crc8_table);
83
84/* periodic measure commands (high precision mode) */
85static const char periodic_measure_commands_hpm[][SHT3X_CMD_LENGTH] = {
86 /* 0.5 measurements per second */
87 {0x20, 0x32},
88 /* 1 measurements per second */
89 {0x21, 0x30},
90 /* 2 measurements per second */
91 {0x22, 0x36},
92 /* 4 measurements per second */
93 {0x23, 0x34},
94 /* 10 measurements per second */
95 {0x27, 0x37},
96};
97
98/* periodic measure commands (low power mode) */
99static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = {
100 /* 0.5 measurements per second */
101 {0x20, 0x2f},
102 /* 1 measurements per second */
103 {0x21, 0x2d},
104 /* 2 measurements per second */
105 {0x22, 0x2b},
106 /* 4 measurements per second */
107 {0x23, 0x29},
108 /* 10 measurements per second */
109 {0x27, 0x2a},
110};
111
112struct sht3x_limit_commands {
113 const char read_command[SHT3X_CMD_LENGTH];
114 const char write_command[SHT3X_CMD_LENGTH];
115};
116
117static const struct sht3x_limit_commands limit_commands[] = {
118 /* temp1_max, humidity1_max */
119 [limit_max] = { {0xe1, 0x1f}, {0x61, 0x1d} },
120 /* temp_1_max_hyst, humidity1_max_hyst */
121 [limit_max_hyst] = { {0xe1, 0x14}, {0x61, 0x16} },
122 /* temp1_min, humidity1_min */
123 [limit_min] = { {0xe1, 0x02}, {0x61, 0x00} },
124 /* temp_1_min_hyst, humidity1_min_hyst */
125 [limit_min_hyst] = { {0xe1, 0x09}, {0x61, 0x0B} },
126};
127
128#define SHT3X_NUM_LIMIT_CMD ARRAY_SIZE(limit_commands)
129
130static const u16 mode_to_update_interval[] = {
131 0,
132 2000,
133 1000,
134 500,
135 250,
136 100,
137};
138
139struct sht3x_data {
140 struct i2c_client *client;
141 struct mutex i2c_lock; /* lock for sending i2c commands */
142 struct mutex data_lock; /* lock for updating driver data */
143
144 u8 mode;
145 const unsigned char *command;
146 u32 wait_time; /* in us*/
147 unsigned long last_update; /* last update in periodic mode*/
148
149 struct sht3x_platform_data setup;
150
151 /*
152 * cached values for temperature and humidity and limits
153 * the limits arrays have the following order:
154 * max, max_hyst, min, min_hyst
155 */
156 int temperature;
157 int temperature_limits[SHT3X_NUM_LIMIT_CMD];
158 u32 humidity;
159 u32 humidity_limits[SHT3X_NUM_LIMIT_CMD];
160};
161
162static u8 get_mode_from_update_interval(u16 value)
163{
164 size_t index;
165 u8 number_of_modes = ARRAY_SIZE(mode_to_update_interval);
166
167 if (value == 0)
168 return 0;
169
170 /* find next faster update interval */
171 for (index = 1; index < number_of_modes; index++) {
172 if (mode_to_update_interval[index] <= value)
173 return index;
174 }
175
176 return number_of_modes - 1;
177}
178
179static int sht3x_read_from_command(struct i2c_client *client,
180 struct sht3x_data *data,
181 const char *command,
182 char *buf, int length, u32 wait_time)
183{
184 int ret;
185
186 mutex_lock(&data->i2c_lock);
187 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
188
189 if (ret != SHT3X_CMD_LENGTH) {
190 ret = ret < 0 ? ret : -EIO;
191 goto out;
192 }
193
194 if (wait_time)
195 usleep_range(wait_time, wait_time + 1000);
196
197 ret = i2c_master_recv(client, buf, length);
198 if (ret != length) {
199 ret = ret < 0 ? ret : -EIO;
200 goto out;
201 }
202
203 ret = 0;
204out:
205 mutex_unlock(&data->i2c_lock);
206 return ret;
207}
208
209static int sht3x_extract_temperature(u16 raw)
210{
211 /*
212 * From datasheet:
213 * T = -45 + 175 * ST / 2^16
214 * Adapted for integer fixed point (3 digit) arithmetic.
215 */
216 return ((21875 * (int)raw) >> 13) - 45000;
217}
218
219static u32 sht3x_extract_humidity(u16 raw)
220{
221 /*
222 * From datasheet:
223 * RH = 100 * SRH / 2^16
224 * Adapted for integer fixed point (3 digit) arithmetic.
225 */
226 return (12500 * (u32)raw) >> 13;
227}
228
229static struct sht3x_data *sht3x_update_client(struct device *dev)
230{
231 struct sht3x_data *data = dev_get_drvdata(dev);
232 struct i2c_client *client = data->client;
233 u16 interval_ms = mode_to_update_interval[data->mode];
234 unsigned long interval_jiffies = msecs_to_jiffies(interval_ms);
235 unsigned char buf[SHT3X_RESPONSE_LENGTH];
236 u16 val;
237 int ret = 0;
238
239 mutex_lock(&data->data_lock);
240 /*
241 * Only update cached readings once per update interval in periodic
242 * mode. In single shot mode the sensor measures values on demand, so
243 * every time the sysfs interface is called, a measurement is triggered.
244 * In periodic mode however, the measurement process is handled
245 * internally by the sensor and reading out sensor values only makes
246 * sense if a new reading is available.
247 */
248 if (time_after(jiffies, data->last_update + interval_jiffies)) {
249 ret = sht3x_read_from_command(client, data, data->command, buf,
250 sizeof(buf), data->wait_time);
251 if (ret)
252 goto out;
253
254 val = be16_to_cpup((__be16 *)buf);
255 data->temperature = sht3x_extract_temperature(val);
256 val = be16_to_cpup((__be16 *)(buf + 3));
257 data->humidity = sht3x_extract_humidity(val);
258 data->last_update = jiffies;
259 }
260
261out:
262 mutex_unlock(&data->data_lock);
263 if (ret)
264 return ERR_PTR(ret);
265
266 return data;
267}
268
269/* sysfs attributes */
270static ssize_t temp1_input_show(struct device *dev,
271 struct device_attribute *attr, char *buf)
272{
273 struct sht3x_data *data = sht3x_update_client(dev);
274
275 if (IS_ERR(data))
276 return PTR_ERR(data);
277
278 return sprintf(buf, "%d\n", data->temperature);
279}
280
281static ssize_t humidity1_input_show(struct device *dev,
282 struct device_attribute *attr, char *buf)
283{
284 struct sht3x_data *data = sht3x_update_client(dev);
285
286 if (IS_ERR(data))
287 return PTR_ERR(data);
288
289 return sprintf(buf, "%u\n", data->humidity);
290}
291
292/*
293 * limits_update must only be called from probe or with data_lock held
294 */
295static int limits_update(struct sht3x_data *data)
296{
297 int ret;
298 u8 index;
299 int temperature;
300 u32 humidity;
301 u16 raw;
302 char buffer[SHT3X_RESPONSE_LENGTH];
303 const struct sht3x_limit_commands *commands;
304 struct i2c_client *client = data->client;
305
306 for (index = 0; index < SHT3X_NUM_LIMIT_CMD; index++) {
307 commands = &limit_commands[index];
308 ret = sht3x_read_from_command(client, data,
309 commands->read_command, buffer,
310 SHT3X_RESPONSE_LENGTH, 0);
311
312 if (ret)
313 return ret;
314
315 raw = be16_to_cpup((__be16 *)buffer);
316 temperature = sht3x_extract_temperature((raw & 0x01ff) << 7);
317 humidity = sht3x_extract_humidity(raw & 0xfe00);
318 data->temperature_limits[index] = temperature;
319 data->humidity_limits[index] = humidity;
320 }
321
322 return ret;
323}
324
325static ssize_t temp1_limit_show(struct device *dev,
326 struct device_attribute *attr,
327 char *buf)
328{
329 struct sht3x_data *data = dev_get_drvdata(dev);
330 u8 index = to_sensor_dev_attr(attr)->index;
331 int temperature_limit = data->temperature_limits[index];
332
333 return scnprintf(buf, PAGE_SIZE, "%d\n", temperature_limit);
334}
335
336static ssize_t humidity1_limit_show(struct device *dev,
337 struct device_attribute *attr,
338 char *buf)
339{
340 struct sht3x_data *data = dev_get_drvdata(dev);
341 u8 index = to_sensor_dev_attr(attr)->index;
342 u32 humidity_limit = data->humidity_limits[index];
343
344 return scnprintf(buf, PAGE_SIZE, "%u\n", humidity_limit);
345}
346
347/*
348 * limit_store must only be called with data_lock held
349 */
350static size_t limit_store(struct device *dev,
351 size_t count,
352 u8 index,
353 int temperature,
354 u32 humidity)
355{
356 char buffer[SHT3X_CMD_LENGTH + SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
357 char *position = buffer;
358 int ret;
359 u16 raw;
360 struct sht3x_data *data = dev_get_drvdata(dev);
361 struct i2c_client *client = data->client;
362 const struct sht3x_limit_commands *commands;
363
364 commands = &limit_commands[index];
365
366 memcpy(position, commands->write_command, SHT3X_CMD_LENGTH);
367 position += SHT3X_CMD_LENGTH;
368 /*
369 * ST = (T + 45) / 175 * 2^16
370 * SRH = RH / 100 * 2^16
371 * adapted for fixed point arithmetic and packed the same as
372 * in limit_show()
373 */
374 raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7);
375 raw |= ((humidity * 42950) >> 16) & 0xfe00;
376
377 *((__be16 *)position) = cpu_to_be16(raw);
378 position += SHT3X_WORD_LEN;
379 *position = crc8(sht3x_crc8_table,
380 position - SHT3X_WORD_LEN,
381 SHT3X_WORD_LEN,
382 SHT3X_CRC8_INIT);
383
384 mutex_lock(&data->i2c_lock);
385 ret = i2c_master_send(client, buffer, sizeof(buffer));
386 mutex_unlock(&data->i2c_lock);
387
388 if (ret != sizeof(buffer))
389 return ret < 0 ? ret : -EIO;
390
391 data->temperature_limits[index] = temperature;
392 data->humidity_limits[index] = humidity;
393 return count;
394}
395
396static ssize_t temp1_limit_store(struct device *dev,
397 struct device_attribute *attr,
398 const char *buf,
399 size_t count)
400{
401 int temperature;
402 int ret;
403 struct sht3x_data *data = dev_get_drvdata(dev);
404 u8 index = to_sensor_dev_attr(attr)->index;
405
406 ret = kstrtoint(buf, 0, &temperature);
407 if (ret)
408 return ret;
409
410 temperature = clamp_val(temperature, SHT3X_MIN_TEMPERATURE,
411 SHT3X_MAX_TEMPERATURE);
412 mutex_lock(&data->data_lock);
413 ret = limit_store(dev, count, index, temperature,
414 data->humidity_limits[index]);
415 mutex_unlock(&data->data_lock);
416
417 return ret;
418}
419
420static ssize_t humidity1_limit_store(struct device *dev,
421 struct device_attribute *attr,
422 const char *buf,
423 size_t count)
424{
425 u32 humidity;
426 int ret;
427 struct sht3x_data *data = dev_get_drvdata(dev);
428 u8 index = to_sensor_dev_attr(attr)->index;
429
430 ret = kstrtou32(buf, 0, &humidity);
431 if (ret)
432 return ret;
433
434 humidity = clamp_val(humidity, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY);
435 mutex_lock(&data->data_lock);
436 ret = limit_store(dev, count, index, data->temperature_limits[index],
437 humidity);
438 mutex_unlock(&data->data_lock);
439
440 return ret;
441}
442
443static void sht3x_select_command(struct sht3x_data *data)
444{
445 /*
446 * In blocking mode (clock stretching mode) the I2C bus
447 * is blocked for other traffic, thus the call to i2c_master_recv()
448 * will wait until the data is ready. For non blocking mode, we
449 * have to wait ourselves.
450 */
451 if (data->mode > 0) {
452 data->command = sht3x_cmd_measure_periodic_mode;
453 data->wait_time = 0;
454 } else if (data->setup.blocking_io) {
455 data->command = data->setup.high_precision ?
456 sht3x_cmd_measure_blocking_hpm :
457 sht3x_cmd_measure_blocking_lpm;
458 data->wait_time = 0;
459 } else {
460 if (data->setup.high_precision) {
461 data->command = sht3x_cmd_measure_nonblocking_hpm;
462 data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_HPM;
463 } else {
464 data->command = sht3x_cmd_measure_nonblocking_lpm;
465 data->wait_time = SHT3X_NONBLOCKING_WAIT_TIME_LPM;
466 }
467 }
468}
469
470static int status_register_read(struct device *dev,
471 struct device_attribute *attr,
472 char *buffer, int length)
473{
474 int ret;
475 struct sht3x_data *data = dev_get_drvdata(dev);
476 struct i2c_client *client = data->client;
477
478 ret = sht3x_read_from_command(client, data, sht3x_cmd_read_status_reg,
479 buffer, length, 0);
480
481 return ret;
482}
483
484static ssize_t temp1_alarm_show(struct device *dev,
485 struct device_attribute *attr,
486 char *buf)
487{
488 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
489 int ret;
490
491 ret = status_register_read(dev, attr, buffer,
492 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
493 if (ret)
494 return ret;
495
496 return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x04));
497}
498
499static ssize_t humidity1_alarm_show(struct device *dev,
500 struct device_attribute *attr,
501 char *buf)
502{
503 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
504 int ret;
505
506 ret = status_register_read(dev, attr, buffer,
507 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
508 if (ret)
509 return ret;
510
511 return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x08));
512}
513
514static ssize_t heater_enable_show(struct device *dev,
515 struct device_attribute *attr,
516 char *buf)
517{
518 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
519 int ret;
520
521 ret = status_register_read(dev, attr, buffer,
522 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
523 if (ret)
524 return ret;
525
526 return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x20));
527}
528
529static ssize_t heater_enable_store(struct device *dev,
530 struct device_attribute *attr,
531 const char *buf,
532 size_t count)
533{
534 struct sht3x_data *data = dev_get_drvdata(dev);
535 struct i2c_client *client = data->client;
536 int ret;
537 bool status;
538
539 ret = kstrtobool(buf, &status);
540 if (ret)
541 return ret;
542
543 mutex_lock(&data->i2c_lock);
544
545 if (status)
546 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_on,
547 SHT3X_CMD_LENGTH);
548 else
549 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_off,
550 SHT3X_CMD_LENGTH);
551
552 mutex_unlock(&data->i2c_lock);
553
554 return ret;
555}
556
557static ssize_t update_interval_show(struct device *dev,
558 struct device_attribute *attr,
559 char *buf)
560{
561 struct sht3x_data *data = dev_get_drvdata(dev);
562
563 return scnprintf(buf, PAGE_SIZE, "%u\n",
564 mode_to_update_interval[data->mode]);
565}
566
567static ssize_t update_interval_store(struct device *dev,
568 struct device_attribute *attr,
569 const char *buf,
570 size_t count)
571{
572 u16 update_interval;
573 u8 mode;
574 int ret;
575 const char *command;
576 struct sht3x_data *data = dev_get_drvdata(dev);
577 struct i2c_client *client = data->client;
578
579 ret = kstrtou16(buf, 0, &update_interval);
580 if (ret)
581 return ret;
582
583 mode = get_mode_from_update_interval(update_interval);
584
585 mutex_lock(&data->data_lock);
586 /* mode did not change */
587 if (mode == data->mode) {
588 mutex_unlock(&data->data_lock);
589 return count;
590 }
591
592 mutex_lock(&data->i2c_lock);
593 /*
594 * Abort periodic measure mode.
595 * To do any changes to the configuration while in periodic mode, we
596 * have to send a break command to the sensor, which then falls back
597 * to single shot (mode = 0).
598 */
599 if (data->mode > 0) {
600 ret = i2c_master_send(client, sht3x_cmd_break,
601 SHT3X_CMD_LENGTH);
602 if (ret != SHT3X_CMD_LENGTH)
603 goto out;
604 data->mode = 0;
605 }
606
607 if (mode > 0) {
608 if (data->setup.high_precision)
609 command = periodic_measure_commands_hpm[mode - 1];
610 else
611 command = periodic_measure_commands_lpm[mode - 1];
612
613 /* select mode */
614 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
615 if (ret != SHT3X_CMD_LENGTH)
616 goto out;
617 }
618
619 /* select mode and command */
620 data->mode = mode;
621 sht3x_select_command(data);
622
623out:
624 mutex_unlock(&data->i2c_lock);
625 mutex_unlock(&data->data_lock);
626 if (ret != SHT3X_CMD_LENGTH)
627 return ret < 0 ? ret : -EIO;
628
629 return count;
630}
631
632static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, temp1_input_show, NULL, 0);
633static SENSOR_DEVICE_ATTR(humidity1_input, S_IRUGO, humidity1_input_show,
634 NULL, 0);
635static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO | S_IWUSR,
636 temp1_limit_show, temp1_limit_store,
637 limit_max);
638static SENSOR_DEVICE_ATTR(humidity1_max, S_IRUGO | S_IWUSR,
639 humidity1_limit_show, humidity1_limit_store,
640 limit_max);
641static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO | S_IWUSR,
642 temp1_limit_show, temp1_limit_store,
643 limit_max_hyst);
644static SENSOR_DEVICE_ATTR(humidity1_max_hyst, S_IRUGO | S_IWUSR,
645 humidity1_limit_show, humidity1_limit_store,
646 limit_max_hyst);
647static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO | S_IWUSR,
648 temp1_limit_show, temp1_limit_store,
649 limit_min);
650static SENSOR_DEVICE_ATTR(humidity1_min, S_IRUGO | S_IWUSR,
651 humidity1_limit_show, humidity1_limit_store,
652 limit_min);
653static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO | S_IWUSR,
654 temp1_limit_show, temp1_limit_store,
655 limit_min_hyst);
656static SENSOR_DEVICE_ATTR(humidity1_min_hyst, S_IRUGO | S_IWUSR,
657 humidity1_limit_show, humidity1_limit_store,
658 limit_min_hyst);
659static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, temp1_alarm_show, NULL, 0);
660static SENSOR_DEVICE_ATTR(humidity1_alarm, S_IRUGO, humidity1_alarm_show,
661 NULL, 0);
662static SENSOR_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,
663 heater_enable_show, heater_enable_store, 0);
664static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
665 update_interval_show, update_interval_store, 0);
666
667static struct attribute *sht3x_attrs[] = {
668 &sensor_dev_attr_temp1_input.dev_attr.attr,
669 &sensor_dev_attr_humidity1_input.dev_attr.attr,
670 &sensor_dev_attr_temp1_max.dev_attr.attr,
671 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
672 &sensor_dev_attr_humidity1_max.dev_attr.attr,
673 &sensor_dev_attr_humidity1_max_hyst.dev_attr.attr,
674 &sensor_dev_attr_temp1_min.dev_attr.attr,
675 &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
676 &sensor_dev_attr_humidity1_min.dev_attr.attr,
677 &sensor_dev_attr_humidity1_min_hyst.dev_attr.attr,
678 &sensor_dev_attr_temp1_alarm.dev_attr.attr,
679 &sensor_dev_attr_humidity1_alarm.dev_attr.attr,
680 &sensor_dev_attr_heater_enable.dev_attr.attr,
681 &sensor_dev_attr_update_interval.dev_attr.attr,
682 NULL
683};
684
685static struct attribute *sts3x_attrs[] = {
686 &sensor_dev_attr_temp1_input.dev_attr.attr,
687 NULL
688};
689
690ATTRIBUTE_GROUPS(sht3x);
691ATTRIBUTE_GROUPS(sts3x);
692
693static int sht3x_probe(struct i2c_client *client,
694 const struct i2c_device_id *id)
695{
696 int ret;
697 struct sht3x_data *data;
698 struct device *hwmon_dev;
699 struct i2c_adapter *adap = client->adapter;
700 struct device *dev = &client->dev;
701 const struct attribute_group **attribute_groups;
702
703 /*
704 * we require full i2c support since the sht3x uses multi-byte read and
705 * writes as well as multi-byte commands which are not supported by
706 * the smbus protocol
707 */
708 if (!i2c_check_functionality(adap, I2C_FUNC_I2C))
709 return -ENODEV;
710
711 ret = i2c_master_send(client, sht3x_cmd_clear_status_reg,
712 SHT3X_CMD_LENGTH);
713 if (ret != SHT3X_CMD_LENGTH)
714 return ret < 0 ? ret : -ENODEV;
715
716 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
717 if (!data)
718 return -ENOMEM;
719
720 data->setup.blocking_io = false;
721 data->setup.high_precision = true;
722 data->mode = 0;
723 data->last_update = jiffies - msecs_to_jiffies(3000);
724 data->client = client;
725 crc8_populate_msb(sht3x_crc8_table, SHT3X_CRC8_POLYNOMIAL);
726
727 if (client->dev.platform_data)
728 data->setup = *(struct sht3x_platform_data *)dev->platform_data;
729
730 sht3x_select_command(data);
731
732 mutex_init(&data->i2c_lock);
733 mutex_init(&data->data_lock);
734
735 /*
736 * An attempt to read limits register too early
737 * causes a NACK response from the chip.
738 * Waiting for an empirical delay of 500 us solves the issue.
739 */
740 usleep_range(500, 600);
741
742 ret = limits_update(data);
743 if (ret)
744 return ret;
745
746 if (id->driver_data == sts3x)
747 attribute_groups = sts3x_groups;
748 else
749 attribute_groups = sht3x_groups;
750
751 hwmon_dev = devm_hwmon_device_register_with_groups(dev,
752 client->name,
753 data,
754 attribute_groups);
755
756 if (IS_ERR(hwmon_dev))
757 dev_dbg(dev, "unable to register hwmon device\n");
758
759 return PTR_ERR_OR_ZERO(hwmon_dev);
760}
761
762/* device ID table */
763static const struct i2c_device_id sht3x_ids[] = {
764 {"sht3x", sht3x},
765 {"sts3x", sts3x},
766 {}
767};
768
769MODULE_DEVICE_TABLE(i2c, sht3x_ids);
770
771static struct i2c_driver sht3x_i2c_driver = {
772 .driver.name = "sht3x",
773 .probe = sht3x_probe,
774 .id_table = sht3x_ids,
775};
776
777module_i2c_driver(sht3x_i2c_driver);
778
779MODULE_AUTHOR("David Frey <david.frey@sensirion.com>");
780MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>");
781MODULE_DESCRIPTION("Sensirion SHT3x humidity and temperature sensor driver");
782MODULE_LICENSE("GPL");