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/debugfs.h>
14 #include <linux/delay.h>
15 #include <linux/err.h>
16 #include <linux/hwmon.h>
17 #include <linux/hwmon-sysfs.h>
18 #include <linux/i2c.h>
19 #include <linux/init.h>
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/slab.h>
23 #include <linux/jiffies.h>
24 #include <linux/unaligned.h>
25
26 /* commands (high repeatability mode) */
27 static const unsigned char sht3x_cmd_measure_single_hpm[] = { 0x24, 0x00 };
28
29 /* commands (medium repeatability mode) */
30 static const unsigned char sht3x_cmd_measure_single_mpm[] = { 0x24, 0x0b };
31
32 /* commands (low repeatability mode) */
33 static const unsigned char sht3x_cmd_measure_single_lpm[] = { 0x24, 0x16 };
34
35 /* commands for periodic mode */
36 static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 };
37 static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 };
38
39 /* commands for heater control */
40 static const unsigned char sht3x_cmd_heater_on[] = { 0x30, 0x6d };
41 static const unsigned char sht3x_cmd_heater_off[] = { 0x30, 0x66 };
42
43 /* other commands */
44 static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d };
45 static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 };
46 static const unsigned char sht3x_cmd_read_serial_number[] = { 0x37, 0x80 };
47
48 /* delays for single-shot mode i2c commands, both in us */
49 #define SHT3X_SINGLE_WAIT_TIME_HPM 15000
50 #define SHT3X_SINGLE_WAIT_TIME_MPM 6000
51 #define SHT3X_SINGLE_WAIT_TIME_LPM 4000
52
53 #define SHT3X_WORD_LEN 2
54 #define SHT3X_CMD_LENGTH 2
55 #define SHT3X_CRC8_LEN 1
56 #define SHT3X_RESPONSE_LENGTH 6
57 #define SHT3X_CRC8_POLYNOMIAL 0x31
58 #define SHT3X_CRC8_INIT 0xFF
59 #define SHT3X_MIN_TEMPERATURE -45000
60 #define SHT3X_MAX_TEMPERATURE 130000
61 #define SHT3X_MIN_HUMIDITY 0
62 #define SHT3X_MAX_HUMIDITY 100000
63
64 enum sht3x_chips {
65 sht3x = 1,
66 sts3x,
67 };
68
69 enum sht3x_limits {
70 limit_max = 0,
71 limit_max_hyst,
72 limit_min,
73 limit_min_hyst,
74 };
75
76 enum sht3x_repeatability {
77 low_repeatability,
78 medium_repeatability,
79 high_repeatability,
80 };
81
82 DECLARE_CRC8_TABLE(sht3x_crc8_table);
83
84 /* periodic measure commands (high repeatability mode) */
85 static 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 (medium repeatability) */
99 static const char periodic_measure_commands_mpm[][SHT3X_CMD_LENGTH] = {
100 /* 0.5 measurements per second */
101 {0x20, 0x24},
102 /* 1 measurements per second */
103 {0x21, 0x26},
104 /* 2 measurements per second */
105 {0x22, 0x20},
106 /* 4 measurements per second */
107 {0x23, 0x22},
108 /* 10 measurements per second */
109 {0x27, 0x21},
110 };
111
112 /* periodic measure commands (low repeatability mode) */
113 static const char periodic_measure_commands_lpm[][SHT3X_CMD_LENGTH] = {
114 /* 0.5 measurements per second */
115 {0x20, 0x2f},
116 /* 1 measurements per second */
117 {0x21, 0x2d},
118 /* 2 measurements per second */
119 {0x22, 0x2b},
120 /* 4 measurements per second */
121 {0x23, 0x29},
122 /* 10 measurements per second */
123 {0x27, 0x2a},
124 };
125
126 struct sht3x_limit_commands {
127 const char read_command[SHT3X_CMD_LENGTH];
128 const char write_command[SHT3X_CMD_LENGTH];
129 };
130
131 static const struct sht3x_limit_commands limit_commands[] = {
132 /* temp1_max, humidity1_max */
133 [limit_max] = { {0xe1, 0x1f}, {0x61, 0x1d} },
134 /* temp_1_max_hyst, humidity1_max_hyst */
135 [limit_max_hyst] = { {0xe1, 0x14}, {0x61, 0x16} },
136 /* temp1_min, humidity1_min */
137 [limit_min] = { {0xe1, 0x02}, {0x61, 0x00} },
138 /* temp_1_min_hyst, humidity1_min_hyst */
139 [limit_min_hyst] = { {0xe1, 0x09}, {0x61, 0x0B} },
140 };
141
142 #define SHT3X_NUM_LIMIT_CMD ARRAY_SIZE(limit_commands)
143
144 static const u16 mode_to_update_interval[] = {
145 0,
146 2000,
147 1000,
148 500,
149 250,
150 100,
151 };
152
153 static const struct hwmon_channel_info * const sht3x_channel_info[] = {
154 HWMON_CHANNEL_INFO(chip, HWMON_C_UPDATE_INTERVAL),
155 HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT | HWMON_T_MIN |
156 HWMON_T_MIN_HYST | HWMON_T_MAX |
157 HWMON_T_MAX_HYST | HWMON_T_ALARM),
158 HWMON_CHANNEL_INFO(humidity, HWMON_H_INPUT | HWMON_H_MIN |
159 HWMON_H_MIN_HYST | HWMON_H_MAX |
160 HWMON_H_MAX_HYST | HWMON_H_ALARM),
161 NULL,
162 };
163
164 struct sht3x_data {
165 struct i2c_client *client;
166 enum sht3x_chips chip_id;
167 struct mutex i2c_lock; /* lock for sending i2c commands */
168 struct mutex data_lock; /* lock for updating driver data */
169
170 u8 mode;
171 const unsigned char *command;
172 u32 wait_time; /* in us*/
173 unsigned long last_update; /* last update in periodic mode*/
174 enum sht3x_repeatability repeatability;
175 u32 serial_number;
176
177 /*
178 * cached values for temperature and humidity and limits
179 * the limits arrays have the following order:
180 * max, max_hyst, min, min_hyst
181 */
182 int temperature;
183 int temperature_limits[SHT3X_NUM_LIMIT_CMD];
184 u32 humidity;
185 u32 humidity_limits[SHT3X_NUM_LIMIT_CMD];
186 };
187
get_mode_from_update_interval(u16 value)188 static u8 get_mode_from_update_interval(u16 value)
189 {
190 size_t index;
191 u8 number_of_modes = ARRAY_SIZE(mode_to_update_interval);
192
193 if (value == 0)
194 return 0;
195
196 /* find next faster update interval */
197 for (index = 1; index < number_of_modes; index++) {
198 if (mode_to_update_interval[index] <= value)
199 return index;
200 }
201
202 return number_of_modes - 1;
203 }
204
sht3x_read_from_command(struct i2c_client * client,struct sht3x_data * data,const char * command,char * buf,int length,u32 wait_time)205 static int sht3x_read_from_command(struct i2c_client *client,
206 struct sht3x_data *data,
207 const char *command,
208 char *buf, int length, u32 wait_time)
209 {
210 int ret;
211
212 mutex_lock(&data->i2c_lock);
213 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
214
215 if (ret != SHT3X_CMD_LENGTH) {
216 ret = ret < 0 ? ret : -EIO;
217 goto out;
218 }
219
220 if (wait_time)
221 usleep_range(wait_time, wait_time + 1000);
222
223 ret = i2c_master_recv(client, buf, length);
224 if (ret != length) {
225 ret = ret < 0 ? ret : -EIO;
226 goto out;
227 }
228
229 ret = 0;
230 out:
231 mutex_unlock(&data->i2c_lock);
232 return ret;
233 }
234
sht3x_extract_temperature(u16 raw)235 static int sht3x_extract_temperature(u16 raw)
236 {
237 /*
238 * From datasheet:
239 * T = -45 + 175 * ST / 2^16
240 * Adapted for integer fixed point (3 digit) arithmetic.
241 */
242 return ((21875 * (int)raw) >> 13) - 45000;
243 }
244
sht3x_extract_humidity(u16 raw)245 static u32 sht3x_extract_humidity(u16 raw)
246 {
247 /*
248 * From datasheet:
249 * RH = 100 * SRH / 2^16
250 * Adapted for integer fixed point (3 digit) arithmetic.
251 */
252 return (12500 * (u32)raw) >> 13;
253 }
254
sht3x_update_client(struct device * dev)255 static struct sht3x_data *sht3x_update_client(struct device *dev)
256 {
257 struct sht3x_data *data = dev_get_drvdata(dev);
258 struct i2c_client *client = data->client;
259 u16 interval_ms = mode_to_update_interval[data->mode];
260 unsigned long interval_jiffies = msecs_to_jiffies(interval_ms);
261 unsigned char buf[SHT3X_RESPONSE_LENGTH];
262 u16 val;
263 int ret = 0;
264
265 mutex_lock(&data->data_lock);
266 /*
267 * Only update cached readings once per update interval in periodic
268 * mode. In single shot mode the sensor measures values on demand, so
269 * every time the sysfs interface is called, a measurement is triggered.
270 * In periodic mode however, the measurement process is handled
271 * internally by the sensor and reading out sensor values only makes
272 * sense if a new reading is available.
273 */
274 if (time_after(jiffies, data->last_update + interval_jiffies)) {
275 ret = sht3x_read_from_command(client, data, data->command, buf,
276 sizeof(buf), data->wait_time);
277 if (ret)
278 goto out;
279
280 val = get_unaligned_be16(buf);
281 data->temperature = sht3x_extract_temperature(val);
282 val = get_unaligned_be16(buf + 3);
283 data->humidity = sht3x_extract_humidity(val);
284 data->last_update = jiffies;
285 }
286
287 out:
288 mutex_unlock(&data->data_lock);
289 if (ret)
290 return ERR_PTR(ret);
291
292 return data;
293 }
294
temp1_input_read(struct device * dev,long * temp)295 static int temp1_input_read(struct device *dev, long *temp)
296 {
297 struct sht3x_data *data = sht3x_update_client(dev);
298
299 if (IS_ERR(data))
300 return PTR_ERR(data);
301
302 *temp = data->temperature;
303 return 0;
304 }
305
humidity1_input_read(struct device * dev,long * humidity)306 static int humidity1_input_read(struct device *dev, long *humidity)
307 {
308 struct sht3x_data *data = sht3x_update_client(dev);
309
310 if (IS_ERR(data))
311 return PTR_ERR(data);
312
313 *humidity = data->humidity;
314 return 0;
315 }
316
317 /*
318 * limits_update must only be called from probe or with data_lock held
319 */
limits_update(struct sht3x_data * data)320 static int limits_update(struct sht3x_data *data)
321 {
322 int ret;
323 u8 index;
324 int temperature;
325 u32 humidity;
326 u16 raw;
327 char buffer[SHT3X_RESPONSE_LENGTH];
328 const struct sht3x_limit_commands *commands;
329 struct i2c_client *client = data->client;
330
331 for (index = 0; index < SHT3X_NUM_LIMIT_CMD; index++) {
332 commands = &limit_commands[index];
333 ret = sht3x_read_from_command(client, data,
334 commands->read_command, buffer,
335 SHT3X_RESPONSE_LENGTH, 0);
336
337 if (ret)
338 return ret;
339
340 raw = get_unaligned_be16(buffer);
341 temperature = sht3x_extract_temperature((raw & 0x01ff) << 7);
342 humidity = sht3x_extract_humidity(raw & 0xfe00);
343 data->temperature_limits[index] = temperature;
344 data->humidity_limits[index] = humidity;
345 }
346
347 return ret;
348 }
349
temp1_limit_read(struct device * dev,int index)350 static int temp1_limit_read(struct device *dev, int index)
351 {
352 struct sht3x_data *data = dev_get_drvdata(dev);
353
354 return data->temperature_limits[index];
355 }
356
humidity1_limit_read(struct device * dev,int index)357 static int humidity1_limit_read(struct device *dev, int index)
358 {
359 struct sht3x_data *data = dev_get_drvdata(dev);
360
361 return data->humidity_limits[index];
362 }
363
364 /*
365 * limit_write must only be called with data_lock held
366 */
limit_write(struct device * dev,u8 index,int temperature,u32 humidity)367 static size_t limit_write(struct device *dev,
368 u8 index,
369 int temperature,
370 u32 humidity)
371 {
372 char buffer[SHT3X_CMD_LENGTH + SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
373 char *position = buffer;
374 int ret;
375 u16 raw;
376 struct sht3x_data *data = dev_get_drvdata(dev);
377 struct i2c_client *client = data->client;
378 const struct sht3x_limit_commands *commands;
379
380 commands = &limit_commands[index];
381
382 memcpy(position, commands->write_command, SHT3X_CMD_LENGTH);
383 position += SHT3X_CMD_LENGTH;
384 /*
385 * ST = (T + 45) / 175 * 2^16
386 * SRH = RH / 100 * 2^16
387 * adapted for fixed point arithmetic and packed the same as
388 * in limit_read()
389 */
390 raw = ((u32)(temperature + 45000) * 24543) >> (16 + 7);
391 raw |= ((humidity * 42950) >> 16) & 0xfe00;
392
393 put_unaligned_be16(raw, position);
394 position += SHT3X_WORD_LEN;
395 *position = crc8(sht3x_crc8_table,
396 position - SHT3X_WORD_LEN,
397 SHT3X_WORD_LEN,
398 SHT3X_CRC8_INIT);
399
400 mutex_lock(&data->i2c_lock);
401 ret = i2c_master_send(client, buffer, sizeof(buffer));
402 mutex_unlock(&data->i2c_lock);
403
404 if (ret != sizeof(buffer))
405 return ret < 0 ? ret : -EIO;
406
407 data->temperature_limits[index] = temperature;
408 data->humidity_limits[index] = humidity;
409
410 return 0;
411 }
412
temp1_limit_write(struct device * dev,int index,int val)413 static int temp1_limit_write(struct device *dev, int index, int val)
414 {
415 int temperature;
416 int ret;
417 struct sht3x_data *data = dev_get_drvdata(dev);
418
419 temperature = clamp_val(val, SHT3X_MIN_TEMPERATURE,
420 SHT3X_MAX_TEMPERATURE);
421 mutex_lock(&data->data_lock);
422 ret = limit_write(dev, index, temperature,
423 data->humidity_limits[index]);
424 mutex_unlock(&data->data_lock);
425
426 return ret;
427 }
428
humidity1_limit_write(struct device * dev,int index,int val)429 static int humidity1_limit_write(struct device *dev, int index, int val)
430 {
431 u32 humidity;
432 int ret;
433 struct sht3x_data *data = dev_get_drvdata(dev);
434
435 humidity = clamp_val(val, SHT3X_MIN_HUMIDITY, SHT3X_MAX_HUMIDITY);
436 mutex_lock(&data->data_lock);
437 ret = limit_write(dev, index, data->temperature_limits[index],
438 humidity);
439 mutex_unlock(&data->data_lock);
440
441 return ret;
442 }
443
sht3x_select_command(struct sht3x_data * data)444 static void sht3x_select_command(struct sht3x_data *data)
445 {
446 /*
447 * For single-shot mode, only non blocking mode is support,
448 * we have to wait ourselves for result.
449 */
450 if (data->mode > 0) {
451 data->command = sht3x_cmd_measure_periodic_mode;
452 data->wait_time = 0;
453 } else {
454 if (data->repeatability == high_repeatability) {
455 data->command = sht3x_cmd_measure_single_hpm;
456 data->wait_time = SHT3X_SINGLE_WAIT_TIME_HPM;
457 } else if (data->repeatability == medium_repeatability) {
458 data->command = sht3x_cmd_measure_single_mpm;
459 data->wait_time = SHT3X_SINGLE_WAIT_TIME_MPM;
460 } else {
461 data->command = sht3x_cmd_measure_single_lpm;
462 data->wait_time = SHT3X_SINGLE_WAIT_TIME_LPM;
463 }
464 }
465 }
466
status_register_read(struct device * dev,char * buffer,int length)467 static int status_register_read(struct device *dev,
468 char *buffer, int length)
469 {
470 int ret;
471 struct sht3x_data *data = dev_get_drvdata(dev);
472 struct i2c_client *client = data->client;
473
474 ret = sht3x_read_from_command(client, data, sht3x_cmd_read_status_reg,
475 buffer, length, 0);
476
477 return ret;
478 }
479
temp1_alarm_read(struct device * dev)480 static int temp1_alarm_read(struct device *dev)
481 {
482 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
483 int ret;
484
485 ret = status_register_read(dev, buffer,
486 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
487 if (ret)
488 return ret;
489
490 return !!(buffer[0] & 0x04);
491 }
492
humidity1_alarm_read(struct device * dev)493 static int humidity1_alarm_read(struct device *dev)
494 {
495 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
496 int ret;
497
498 ret = status_register_read(dev, buffer,
499 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
500 if (ret)
501 return ret;
502
503 return !!(buffer[0] & 0x08);
504 }
505
heater_enable_show(struct device * dev,struct device_attribute * attr,char * buf)506 static ssize_t heater_enable_show(struct device *dev,
507 struct device_attribute *attr,
508 char *buf)
509 {
510 char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
511 int ret;
512
513 ret = status_register_read(dev, buffer,
514 SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
515 if (ret)
516 return ret;
517
518 return sysfs_emit(buf, "%d\n", !!(buffer[0] & 0x20));
519 }
520
heater_enable_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)521 static ssize_t heater_enable_store(struct device *dev,
522 struct device_attribute *attr,
523 const char *buf,
524 size_t count)
525 {
526 struct sht3x_data *data = dev_get_drvdata(dev);
527 struct i2c_client *client = data->client;
528 int ret;
529 bool status;
530
531 ret = kstrtobool(buf, &status);
532 if (ret)
533 return ret;
534
535 mutex_lock(&data->i2c_lock);
536
537 if (status)
538 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_on,
539 SHT3X_CMD_LENGTH);
540 else
541 ret = i2c_master_send(client, (char *)&sht3x_cmd_heater_off,
542 SHT3X_CMD_LENGTH);
543
544 mutex_unlock(&data->i2c_lock);
545
546 return ret;
547 }
548
update_interval_read(struct device * dev)549 static int update_interval_read(struct device *dev)
550 {
551 struct sht3x_data *data = dev_get_drvdata(dev);
552
553 return mode_to_update_interval[data->mode];
554 }
555
update_interval_write(struct device * dev,int val)556 static int update_interval_write(struct device *dev, int val)
557 {
558 u8 mode;
559 int ret;
560 const char *command;
561 struct sht3x_data *data = dev_get_drvdata(dev);
562 struct i2c_client *client = data->client;
563
564 mode = get_mode_from_update_interval(val);
565
566 mutex_lock(&data->data_lock);
567 /* mode did not change */
568 if (mode == data->mode) {
569 mutex_unlock(&data->data_lock);
570 return 0;
571 }
572
573 mutex_lock(&data->i2c_lock);
574 /*
575 * Abort periodic measure mode.
576 * To do any changes to the configuration while in periodic mode, we
577 * have to send a break command to the sensor, which then falls back
578 * to single shot (mode = 0).
579 */
580 if (data->mode > 0) {
581 ret = i2c_master_send(client, sht3x_cmd_break,
582 SHT3X_CMD_LENGTH);
583 if (ret != SHT3X_CMD_LENGTH)
584 goto out;
585 data->mode = 0;
586 }
587
588 if (mode > 0) {
589 if (data->repeatability == high_repeatability)
590 command = periodic_measure_commands_hpm[mode - 1];
591 else if (data->repeatability == medium_repeatability)
592 command = periodic_measure_commands_mpm[mode - 1];
593 else
594 command = periodic_measure_commands_lpm[mode - 1];
595
596 /* select mode */
597 ret = i2c_master_send(client, command, SHT3X_CMD_LENGTH);
598 if (ret != SHT3X_CMD_LENGTH)
599 goto out;
600 }
601
602 /* select mode and command */
603 data->mode = mode;
604 sht3x_select_command(data);
605
606 out:
607 mutex_unlock(&data->i2c_lock);
608 mutex_unlock(&data->data_lock);
609 if (ret != SHT3X_CMD_LENGTH)
610 return ret < 0 ? ret : -EIO;
611
612 return 0;
613 }
614
repeatability_show(struct device * dev,struct device_attribute * attr,char * buf)615 static ssize_t repeatability_show(struct device *dev,
616 struct device_attribute *attr,
617 char *buf)
618 {
619 struct sht3x_data *data = dev_get_drvdata(dev);
620
621 return sysfs_emit(buf, "%d\n", data->repeatability);
622 }
623
repeatability_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)624 static ssize_t repeatability_store(struct device *dev,
625 struct device_attribute *attr,
626 const char *buf,
627 size_t count)
628 {
629 int ret;
630 u8 val;
631
632 struct sht3x_data *data = dev_get_drvdata(dev);
633
634 ret = kstrtou8(buf, 0, &val);
635 if (ret)
636 return ret;
637
638 if (val > 2)
639 return -EINVAL;
640
641 data->repeatability = val;
642
643 return count;
644 }
645
646 static SENSOR_DEVICE_ATTR_RW(heater_enable, heater_enable, 0);
647 static SENSOR_DEVICE_ATTR_RW(repeatability, repeatability, 0);
648
649 static struct attribute *sht3x_attrs[] = {
650 &sensor_dev_attr_heater_enable.dev_attr.attr,
651 &sensor_dev_attr_repeatability.dev_attr.attr,
652 NULL
653 };
654
655 ATTRIBUTE_GROUPS(sht3x);
656
sht3x_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)657 static umode_t sht3x_is_visible(const void *data, enum hwmon_sensor_types type,
658 u32 attr, int channel)
659 {
660 const struct sht3x_data *chip_data = data;
661
662 switch (type) {
663 case hwmon_chip:
664 switch (attr) {
665 case hwmon_chip_update_interval:
666 return 0644;
667 default:
668 break;
669 }
670 break;
671 case hwmon_temp:
672 switch (attr) {
673 case hwmon_temp_input:
674 case hwmon_temp_alarm:
675 return 0444;
676 case hwmon_temp_max:
677 case hwmon_temp_max_hyst:
678 case hwmon_temp_min:
679 case hwmon_temp_min_hyst:
680 return 0644;
681 default:
682 break;
683 }
684 break;
685 case hwmon_humidity:
686 if (chip_data->chip_id == sts3x)
687 break;
688 switch (attr) {
689 case hwmon_humidity_input:
690 case hwmon_humidity_alarm:
691 return 0444;
692 case hwmon_humidity_max:
693 case hwmon_humidity_max_hyst:
694 case hwmon_humidity_min:
695 case hwmon_humidity_min_hyst:
696 return 0644;
697 default:
698 break;
699 }
700 break;
701 default:
702 break;
703 }
704
705 return 0;
706 }
707
sht3x_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)708 static int sht3x_read(struct device *dev, enum hwmon_sensor_types type,
709 u32 attr, int channel, long *val)
710 {
711 enum sht3x_limits index;
712 int ret;
713
714 switch (type) {
715 case hwmon_chip:
716 switch (attr) {
717 case hwmon_chip_update_interval:
718 *val = update_interval_read(dev);
719 break;
720 default:
721 return -EOPNOTSUPP;
722 }
723 break;
724 case hwmon_temp:
725 switch (attr) {
726 case hwmon_temp_input:
727 return temp1_input_read(dev, val);
728 case hwmon_temp_alarm:
729 ret = temp1_alarm_read(dev);
730 if (ret < 0)
731 return ret;
732 *val = ret;
733 break;
734 case hwmon_temp_max:
735 index = limit_max;
736 *val = temp1_limit_read(dev, index);
737 break;
738 case hwmon_temp_max_hyst:
739 index = limit_max_hyst;
740 *val = temp1_limit_read(dev, index);
741 break;
742 case hwmon_temp_min:
743 index = limit_min;
744 *val = temp1_limit_read(dev, index);
745 break;
746 case hwmon_temp_min_hyst:
747 index = limit_min_hyst;
748 *val = temp1_limit_read(dev, index);
749 break;
750 default:
751 return -EOPNOTSUPP;
752 }
753 break;
754 case hwmon_humidity:
755 switch (attr) {
756 case hwmon_humidity_input:
757 return humidity1_input_read(dev, val);
758 case hwmon_humidity_alarm:
759 ret = humidity1_alarm_read(dev);
760 if (ret < 0)
761 return ret;
762 *val = ret;
763 break;
764 case hwmon_humidity_max:
765 index = limit_max;
766 *val = humidity1_limit_read(dev, index);
767 break;
768 case hwmon_humidity_max_hyst:
769 index = limit_max_hyst;
770 *val = humidity1_limit_read(dev, index);
771 break;
772 case hwmon_humidity_min:
773 index = limit_min;
774 *val = humidity1_limit_read(dev, index);
775 break;
776 case hwmon_humidity_min_hyst:
777 index = limit_min_hyst;
778 *val = humidity1_limit_read(dev, index);
779 break;
780 default:
781 return -EOPNOTSUPP;
782 }
783 break;
784 default:
785 return -EOPNOTSUPP;
786 }
787
788 return 0;
789 }
790
sht3x_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)791 static int sht3x_write(struct device *dev, enum hwmon_sensor_types type,
792 u32 attr, int channel, long val)
793 {
794 enum sht3x_limits index;
795
796 switch (type) {
797 case hwmon_chip:
798 switch (attr) {
799 case hwmon_chip_update_interval:
800 return update_interval_write(dev, val);
801 default:
802 return -EOPNOTSUPP;
803 }
804 case hwmon_temp:
805 switch (attr) {
806 case hwmon_temp_max:
807 index = limit_max;
808 break;
809 case hwmon_temp_max_hyst:
810 index = limit_max_hyst;
811 break;
812 case hwmon_temp_min:
813 index = limit_min;
814 break;
815 case hwmon_temp_min_hyst:
816 index = limit_min_hyst;
817 break;
818 default:
819 return -EOPNOTSUPP;
820 }
821 return temp1_limit_write(dev, index, val);
822 case hwmon_humidity:
823 switch (attr) {
824 case hwmon_humidity_max:
825 index = limit_max;
826 break;
827 case hwmon_humidity_max_hyst:
828 index = limit_max_hyst;
829 break;
830 case hwmon_humidity_min:
831 index = limit_min;
832 break;
833 case hwmon_humidity_min_hyst:
834 index = limit_min_hyst;
835 break;
836 default:
837 return -EOPNOTSUPP;
838 }
839 return humidity1_limit_write(dev, index, val);
840 default:
841 return -EOPNOTSUPP;
842 }
843 }
844
sht3x_serial_number_read(struct sht3x_data * data)845 static void sht3x_serial_number_read(struct sht3x_data *data)
846 {
847 int ret;
848 char buffer[SHT3X_RESPONSE_LENGTH];
849 struct i2c_client *client = data->client;
850
851 ret = sht3x_read_from_command(client, data,
852 sht3x_cmd_read_serial_number,
853 buffer,
854 SHT3X_RESPONSE_LENGTH, 0);
855 if (ret)
856 return;
857
858 data->serial_number = (buffer[0] << 24) | (buffer[1] << 16) |
859 (buffer[3] << 8) | buffer[4];
860
861 debugfs_create_u32("serial_number", 0444, client->debugfs, &data->serial_number);
862 }
863
864 static const struct hwmon_ops sht3x_ops = {
865 .is_visible = sht3x_is_visible,
866 .read = sht3x_read,
867 .write = sht3x_write,
868 };
869
870 static const struct hwmon_chip_info sht3x_chip_info = {
871 .ops = &sht3x_ops,
872 .info = sht3x_channel_info,
873 };
874
sht3x_probe(struct i2c_client * client)875 static int sht3x_probe(struct i2c_client *client)
876 {
877 int ret;
878 struct sht3x_data *data;
879 struct device *hwmon_dev;
880 struct i2c_adapter *adap = client->adapter;
881 struct device *dev = &client->dev;
882
883 /*
884 * we require full i2c support since the sht3x uses multi-byte read and
885 * writes as well as multi-byte commands which are not supported by
886 * the smbus protocol
887 */
888 if (!i2c_check_functionality(adap, I2C_FUNC_I2C))
889 return -ENODEV;
890
891 ret = i2c_master_send(client, sht3x_cmd_clear_status_reg,
892 SHT3X_CMD_LENGTH);
893 if (ret != SHT3X_CMD_LENGTH)
894 return ret < 0 ? ret : -ENODEV;
895
896 data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
897 if (!data)
898 return -ENOMEM;
899
900 data->repeatability = high_repeatability;
901 data->mode = 0;
902 data->last_update = jiffies - msecs_to_jiffies(3000);
903 data->client = client;
904 data->chip_id = (uintptr_t)i2c_get_match_data(client);
905 crc8_populate_msb(sht3x_crc8_table, SHT3X_CRC8_POLYNOMIAL);
906
907 sht3x_select_command(data);
908
909 mutex_init(&data->i2c_lock);
910 mutex_init(&data->data_lock);
911
912 /*
913 * An attempt to read limits register too early
914 * causes a NACK response from the chip.
915 * Waiting for an empirical delay of 500 us solves the issue.
916 */
917 usleep_range(500, 600);
918
919 ret = limits_update(data);
920 if (ret)
921 return ret;
922
923 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
924 &sht3x_chip_info, sht3x_groups);
925 if (IS_ERR(hwmon_dev))
926 return PTR_ERR(hwmon_dev);
927
928 sht3x_serial_number_read(data);
929
930 return 0;
931 }
932
933 /* device ID table */
934 static const struct i2c_device_id sht3x_ids[] = {
935 { .name = "sht3x", .driver_data = sht3x },
936 { .name = "sts3x", .driver_data = sts3x },
937 { .name = "sht85", .driver_data = sht3x },
938 { }
939 };
940
941 MODULE_DEVICE_TABLE(i2c, sht3x_ids);
942
943 static const struct of_device_id sht3x_of_match[] = {
944 { .compatible = "sensirion,sht30", .data = (void *)(uintptr_t)sht3x },
945 { .compatible = "sensirion,sts30", .data = (void *)(uintptr_t)sts3x },
946 { }
947 };
948
949 MODULE_DEVICE_TABLE(of, sht3x_of_match);
950
951 static struct i2c_driver sht3x_i2c_driver = {
952 .driver = {
953 .name = "sht3x",
954 .of_match_table = sht3x_of_match,
955 },
956 .probe = sht3x_probe,
957 .id_table = sht3x_ids,
958 };
959 module_i2c_driver(sht3x_i2c_driver);
960
961 MODULE_AUTHOR("David Frey <david.frey@sensirion.com>");
962 MODULE_AUTHOR("Pascal Sachs <pascal.sachs@sensirion.com>");
963 MODULE_DESCRIPTION("Sensirion SHT3x humidity and temperature sensor driver");
964 MODULE_LICENSE("GPL");
965