1/*
2 * STTS751 sensor driver
3 *
4 * Copyright (C) 2016-2017 Istituto Italiano di Tecnologia - RBCS - EDL
5 * Robotics, Brain and Cognitive Sciences department
6 * Electronic Design Laboratory
7 *
8 * Written by Andrea Merello <andrea.merello@gmail.com>
9 *
10 * Based on LM95241 driver and LM90 driver
11 *
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
16 *
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
21 */
22
23#include <linux/bitops.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/interrupt.h>
30#include <linux/jiffies.h>
31#include <linux/module.h>
32#include <linux/mutex.h>
33#include <linux/property.h>
34#include <linux/slab.h>
35#include <linux/sysfs.h>
36#include <linux/util_macros.h>
37
38#define DEVNAME "stts751"
39
40static const unsigned short normal_i2c[] = {
41 0x48, 0x49, 0x38, 0x39, /* STTS751-0 */
42 0x4A, 0x4B, 0x3A, 0x3B, /* STTS751-1 */
43 I2C_CLIENT_END };
44
45#define STTS751_REG_TEMP_H 0x00
46#define STTS751_REG_STATUS 0x01
47#define STTS751_STATUS_TRIPT BIT(0)
48#define STTS751_STATUS_TRIPL BIT(5)
49#define STTS751_STATUS_TRIPH BIT(6)
50#define STTS751_REG_TEMP_L 0x02
51#define STTS751_REG_CONF 0x03
52#define STTS751_CONF_RES_MASK 0x0C
53#define STTS751_CONF_RES_SHIFT 2
54#define STTS751_CONF_EVENT_DIS BIT(7)
55#define STTS751_CONF_STOP BIT(6)
56#define STTS751_REG_RATE 0x04
57#define STTS751_REG_HLIM_H 0x05
58#define STTS751_REG_HLIM_L 0x06
59#define STTS751_REG_LLIM_H 0x07
60#define STTS751_REG_LLIM_L 0x08
61#define STTS751_REG_TLIM 0x20
62#define STTS751_REG_HYST 0x21
63#define STTS751_REG_SMBUS_TO 0x22
64
65#define STTS751_REG_PROD_ID 0xFD
66#define STTS751_REG_MAN_ID 0xFE
67#define STTS751_REG_REV_ID 0xFF
68
69#define STTS751_0_PROD_ID 0x00
70#define STTS751_1_PROD_ID 0x01
71#define ST_MAN_ID 0x53
72
73/*
74 * Possible update intervals are (in mS):
75 * 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 62.5, 31.25
76 * However we are not going to complicate things too much and we stick to the
77 * approx value in mS.
78 */
79static const int stts751_intervals[] = {
80 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 63, 31
81};
82
83static const struct i2c_device_id stts751_id[] = {
84 { "stts751", 0 },
85 { }
86};
87
88static const struct of_device_id stts751_of_match[] = {
89 { .compatible = "stts751" },
90 { },
91};
92MODULE_DEVICE_TABLE(of, stts751_of_match);
93
94struct stts751_priv {
95 struct device *dev;
96 struct i2c_client *client;
97 struct mutex access_lock;
98 u8 interval;
99 int res;
100 int event_max, event_min;
101 int therm;
102 int hyst;
103 bool smbus_timeout;
104 int temp;
105 unsigned long last_update, last_alert_update;
106 u8 config;
107 bool min_alert, max_alert, therm_trip;
108 bool data_valid, alert_valid;
109 bool notify_max, notify_min;
110};
111
112/*
113 * These functions converts temperature from HW format to integer format and
114 * vice-vers. They are (mostly) taken from lm90 driver. Unit is in mC.
115 */
116static int stts751_to_deg(s16 hw_val)
117{
118 return hw_val * 125 / 32;
119}
120
121static s32 stts751_to_hw(int val)
122{
123 return DIV_ROUND_CLOSEST(val, 125) * 32;
124}
125
126static int stts751_adjust_resolution(struct stts751_priv *priv)
127{
128 u8 res;
129
130 switch (priv->interval) {
131 case 9:
132 /* 10 bits */
133 res = 0;
134 break;
135 case 8:
136 /* 11 bits */
137 res = 1;
138 break;
139 default:
140 /* 12 bits */
141 res = 3;
142 break;
143 }
144
145 if (priv->res == res)
146 return 0;
147
148 priv->config &= ~STTS751_CONF_RES_MASK;
149 priv->config |= res << STTS751_CONF_RES_SHIFT;
150 dev_dbg(&priv->client->dev, "setting res %d. config %x",
151 res, priv->config);
152 priv->res = res;
153
154 return i2c_smbus_write_byte_data(priv->client,
155 STTS751_REG_CONF, priv->config);
156}
157
158static int stts751_update_temp(struct stts751_priv *priv)
159{
160 s32 integer1, integer2, frac;
161
162 /*
163 * There is a trick here, like in the lm90 driver. We have to read two
164 * registers to get the sensor temperature, but we have to beware a
165 * conversion could occur between the readings. We could use the
166 * one-shot conversion register, but we don't want to do this (disables
167 * hardware monitoring). So the solution used here is to read the high
168 * byte once, then the low byte, then the high byte again. If the new
169 * high byte matches the old one, then we have a valid reading. Else we
170 * have to read the low byte again, and now we believe we have a correct
171 * reading.
172 */
173 integer1 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H);
174 if (integer1 < 0) {
175 dev_dbg(&priv->client->dev,
176 "I2C read failed (temp H). ret: %x\n", integer1);
177 return integer1;
178 }
179
180 frac = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_L);
181 if (frac < 0) {
182 dev_dbg(&priv->client->dev,
183 "I2C read failed (temp L). ret: %x\n", frac);
184 return frac;
185 }
186
187 integer2 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H);
188 if (integer2 < 0) {
189 dev_dbg(&priv->client->dev,
190 "I2C 2nd read failed (temp H). ret: %x\n", integer2);
191 return integer2;
192 }
193
194 if (integer1 != integer2) {
195 frac = i2c_smbus_read_byte_data(priv->client,
196 STTS751_REG_TEMP_L);
197 if (frac < 0) {
198 dev_dbg(&priv->client->dev,
199 "I2C 2nd read failed (temp L). ret: %x\n",
200 frac);
201 return frac;
202 }
203 }
204
205 priv->temp = stts751_to_deg((integer1 << 8) | frac);
206 return 0;
207}
208
209static int stts751_set_temp_reg16(struct stts751_priv *priv, int temp,
210 u8 hreg, u8 lreg)
211{
212 s32 hwval;
213 int ret;
214
215 hwval = stts751_to_hw(temp);
216
217 ret = i2c_smbus_write_byte_data(priv->client, hreg, hwval >> 8);
218 if (ret)
219 return ret;
220
221 return i2c_smbus_write_byte_data(priv->client, lreg, hwval & 0xff);
222}
223
224static int stts751_set_temp_reg8(struct stts751_priv *priv, int temp, u8 reg)
225{
226 s32 hwval;
227
228 hwval = stts751_to_hw(temp);
229 return i2c_smbus_write_byte_data(priv->client, reg, hwval >> 8);
230}
231
232static int stts751_read_reg16(struct stts751_priv *priv, int *temp,
233 u8 hreg, u8 lreg)
234{
235 int integer, frac;
236
237 integer = i2c_smbus_read_byte_data(priv->client, hreg);
238 if (integer < 0)
239 return integer;
240
241 frac = i2c_smbus_read_byte_data(priv->client, lreg);
242 if (frac < 0)
243 return frac;
244
245 *temp = stts751_to_deg((integer << 8) | frac);
246
247 return 0;
248}
249
250static int stts751_read_reg8(struct stts751_priv *priv, int *temp, u8 reg)
251{
252 int integer;
253
254 integer = i2c_smbus_read_byte_data(priv->client, reg);
255 if (integer < 0)
256 return integer;
257
258 *temp = stts751_to_deg(integer << 8);
259
260 return 0;
261}
262
263/*
264 * Update alert flags without waiting for cache to expire. We detects alerts
265 * immediately for the sake of the alert handler; we still need to deal with
266 * caching to workaround the fact that alarm flags int the status register,
267 * despite what the datasheet claims, gets always cleared on read.
268 */
269static int stts751_update_alert(struct stts751_priv *priv)
270{
271 int ret;
272 bool conv_done;
273 int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]);
274
275 /*
276 * Add another 10% because if we run faster than the HW conversion
277 * rate we will end up in reporting incorrectly alarms.
278 */
279 cache_time += cache_time / 10;
280
281 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_STATUS);
282 if (ret < 0)
283 return ret;
284
285 dev_dbg(&priv->client->dev, "status reg %x\n", ret);
286 conv_done = ret & (STTS751_STATUS_TRIPH | STTS751_STATUS_TRIPL);
287 /*
288 * Reset the cache if the cache time expired, or if we are sure
289 * we have valid data from a device conversion, or if we know
290 * our cache has been never written.
291 *
292 * Note that when the cache has been never written the point is
293 * to correctly initialize the timestamp, rather than clearing
294 * the cache values.
295 *
296 * Note that updating the cache timestamp when we get an alarm flag
297 * is required, otherwise we could incorrectly report alarms to be zero.
298 */
299 if (time_after(jiffies, priv->last_alert_update + cache_time) ||
300 conv_done || !priv->alert_valid) {
301 priv->max_alert = false;
302 priv->min_alert = false;
303 priv->alert_valid = true;
304 priv->last_alert_update = jiffies;
305 dev_dbg(&priv->client->dev, "invalidating alert cache\n");
306 }
307
308 priv->max_alert |= !!(ret & STTS751_STATUS_TRIPH);
309 priv->min_alert |= !!(ret & STTS751_STATUS_TRIPL);
310 priv->therm_trip = !!(ret & STTS751_STATUS_TRIPT);
311
312 dev_dbg(&priv->client->dev, "max_alert: %d, min_alert: %d, therm_trip: %d\n",
313 priv->max_alert, priv->min_alert, priv->therm_trip);
314
315 return 0;
316}
317
318static void stts751_alert(struct i2c_client *client,
319 enum i2c_alert_protocol type, unsigned int data)
320{
321 int ret;
322 struct stts751_priv *priv = i2c_get_clientdata(client);
323
324 if (type != I2C_PROTOCOL_SMBUS_ALERT)
325 return;
326
327 dev_dbg(&client->dev, "alert!");
328
329 mutex_lock(&priv->access_lock);
330 ret = stts751_update_alert(priv);
331 if (ret < 0) {
332 /* default to worst case */
333 priv->max_alert = true;
334 priv->min_alert = true;
335
336 dev_warn(priv->dev,
337 "Alert received, but can't communicate to the device. Triggering all alarms!");
338 }
339
340 if (priv->max_alert) {
341 if (priv->notify_max)
342 dev_notice(priv->dev, "got alert for HIGH temperature");
343 priv->notify_max = false;
344
345 /* unblock alert poll */
346 sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm");
347 }
348
349 if (priv->min_alert) {
350 if (priv->notify_min)
351 dev_notice(priv->dev, "got alert for LOW temperature");
352 priv->notify_min = false;
353
354 /* unblock alert poll */
355 sysfs_notify(&priv->dev->kobj, NULL, "temp1_min_alarm");
356 }
357
358 if (priv->min_alert || priv->max_alert)
359 kobject_uevent(&priv->dev->kobj, KOBJ_CHANGE);
360
361 mutex_unlock(&priv->access_lock);
362}
363
364static int stts751_update(struct stts751_priv *priv)
365{
366 int ret;
367 int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]);
368
369 if (time_after(jiffies, priv->last_update + cache_time) ||
370 !priv->data_valid) {
371 ret = stts751_update_temp(priv);
372 if (ret)
373 return ret;
374
375 ret = stts751_update_alert(priv);
376 if (ret)
377 return ret;
378 priv->data_valid = true;
379 priv->last_update = jiffies;
380 }
381
382 return 0;
383}
384
385static ssize_t max_alarm_show(struct device *dev,
386 struct device_attribute *attr, char *buf)
387{
388 int ret;
389 struct stts751_priv *priv = dev_get_drvdata(dev);
390
391 mutex_lock(&priv->access_lock);
392 ret = stts751_update(priv);
393 if (!ret)
394 priv->notify_max = true;
395 mutex_unlock(&priv->access_lock);
396 if (ret < 0)
397 return ret;
398
399 return snprintf(buf, PAGE_SIZE, "%d\n", priv->max_alert);
400}
401
402static ssize_t min_alarm_show(struct device *dev,
403 struct device_attribute *attr, char *buf)
404{
405 int ret;
406 struct stts751_priv *priv = dev_get_drvdata(dev);
407
408 mutex_lock(&priv->access_lock);
409 ret = stts751_update(priv);
410 if (!ret)
411 priv->notify_min = true;
412 mutex_unlock(&priv->access_lock);
413 if (ret < 0)
414 return ret;
415
416 return snprintf(buf, PAGE_SIZE, "%d\n", priv->min_alert);
417}
418
419static ssize_t input_show(struct device *dev, struct device_attribute *attr,
420 char *buf)
421{
422 int ret;
423 struct stts751_priv *priv = dev_get_drvdata(dev);
424
425 mutex_lock(&priv->access_lock);
426 ret = stts751_update(priv);
427 mutex_unlock(&priv->access_lock);
428 if (ret < 0)
429 return ret;
430
431 return snprintf(buf, PAGE_SIZE, "%d\n", priv->temp);
432}
433
434static ssize_t therm_show(struct device *dev, struct device_attribute *attr,
435 char *buf)
436{
437 struct stts751_priv *priv = dev_get_drvdata(dev);
438
439 return snprintf(buf, PAGE_SIZE, "%d\n", priv->therm);
440}
441
442static ssize_t therm_store(struct device *dev, struct device_attribute *attr,
443 const char *buf, size_t count)
444{
445 int ret;
446 long temp;
447 struct stts751_priv *priv = dev_get_drvdata(dev);
448
449 if (kstrtol(buf, 10, &temp) < 0)
450 return -EINVAL;
451
452 /* HW works in range -64C to +127.937C */
453 temp = clamp_val(temp, -64000, 127937);
454 mutex_lock(&priv->access_lock);
455 ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_TLIM);
456 if (ret)
457 goto exit;
458
459 dev_dbg(&priv->client->dev, "setting therm %ld", temp);
460
461 /*
462 * hysteresis reg is relative to therm, so the HW does not need to be
463 * adjusted, we need to update our local copy only.
464 */
465 priv->hyst = temp - (priv->therm - priv->hyst);
466 priv->therm = temp;
467
468exit:
469 mutex_unlock(&priv->access_lock);
470 if (ret)
471 return ret;
472
473 return count;
474}
475
476static ssize_t hyst_show(struct device *dev, struct device_attribute *attr,
477 char *buf)
478{
479 struct stts751_priv *priv = dev_get_drvdata(dev);
480
481 return snprintf(buf, PAGE_SIZE, "%d\n", priv->hyst);
482}
483
484static ssize_t hyst_store(struct device *dev, struct device_attribute *attr,
485 const char *buf, size_t count)
486{
487 int ret;
488 long temp;
489
490 struct stts751_priv *priv = dev_get_drvdata(dev);
491
492 if (kstrtol(buf, 10, &temp) < 0)
493 return -EINVAL;
494
495 mutex_lock(&priv->access_lock);
496 /* HW works in range -64C to +127.937C */
497 temp = clamp_val(temp, -64000, priv->therm);
498 priv->hyst = temp;
499 dev_dbg(&priv->client->dev, "setting hyst %ld", temp);
500 temp = priv->therm - temp;
501 ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_HYST);
502 mutex_unlock(&priv->access_lock);
503 if (ret)
504 return ret;
505
506 return count;
507}
508
509static ssize_t therm_trip_show(struct device *dev,
510 struct device_attribute *attr, char *buf)
511{
512 int ret;
513 struct stts751_priv *priv = dev_get_drvdata(dev);
514
515 mutex_lock(&priv->access_lock);
516 ret = stts751_update(priv);
517 mutex_unlock(&priv->access_lock);
518 if (ret < 0)
519 return ret;
520
521 return snprintf(buf, PAGE_SIZE, "%d\n", priv->therm_trip);
522}
523
524static ssize_t max_show(struct device *dev, struct device_attribute *attr,
525 char *buf)
526{
527 struct stts751_priv *priv = dev_get_drvdata(dev);
528
529 return snprintf(buf, PAGE_SIZE, "%d\n", priv->event_max);
530}
531
532static ssize_t max_store(struct device *dev, struct device_attribute *attr,
533 const char *buf, size_t count)
534{
535 int ret;
536 long temp;
537 struct stts751_priv *priv = dev_get_drvdata(dev);
538
539 if (kstrtol(buf, 10, &temp) < 0)
540 return -EINVAL;
541
542 mutex_lock(&priv->access_lock);
543 /* HW works in range -64C to +127.937C */
544 temp = clamp_val(temp, priv->event_min, 127937);
545 ret = stts751_set_temp_reg16(priv, temp,
546 STTS751_REG_HLIM_H, STTS751_REG_HLIM_L);
547 if (ret)
548 goto exit;
549
550 dev_dbg(&priv->client->dev, "setting event max %ld", temp);
551 priv->event_max = temp;
552 ret = count;
553exit:
554 mutex_unlock(&priv->access_lock);
555 return ret;
556}
557
558static ssize_t min_show(struct device *dev, struct device_attribute *attr,
559 char *buf)
560{
561 struct stts751_priv *priv = dev_get_drvdata(dev);
562
563 return snprintf(buf, PAGE_SIZE, "%d\n", priv->event_min);
564}
565
566static ssize_t min_store(struct device *dev, struct device_attribute *attr,
567 const char *buf, size_t count)
568{
569 int ret;
570 long temp;
571 struct stts751_priv *priv = dev_get_drvdata(dev);
572
573 if (kstrtol(buf, 10, &temp) < 0)
574 return -EINVAL;
575
576 mutex_lock(&priv->access_lock);
577 /* HW works in range -64C to +127.937C */
578 temp = clamp_val(temp, -64000, priv->event_max);
579 ret = stts751_set_temp_reg16(priv, temp,
580 STTS751_REG_LLIM_H, STTS751_REG_LLIM_L);
581 if (ret)
582 goto exit;
583
584 dev_dbg(&priv->client->dev, "setting event min %ld", temp);
585 priv->event_min = temp;
586 ret = count;
587exit:
588 mutex_unlock(&priv->access_lock);
589 return ret;
590}
591
592static ssize_t interval_show(struct device *dev,
593 struct device_attribute *attr, char *buf)
594{
595 struct stts751_priv *priv = dev_get_drvdata(dev);
596
597 return snprintf(buf, PAGE_SIZE, "%d\n",
598 stts751_intervals[priv->interval]);
599}
600
601static ssize_t interval_store(struct device *dev,
602 struct device_attribute *attr, const char *buf,
603 size_t count)
604{
605 unsigned long val;
606 int idx;
607 int ret = count;
608 struct stts751_priv *priv = dev_get_drvdata(dev);
609
610 if (kstrtoul(buf, 10, &val) < 0)
611 return -EINVAL;
612
613 idx = find_closest_descending(val, stts751_intervals,
614 ARRAY_SIZE(stts751_intervals));
615
616 dev_dbg(&priv->client->dev, "setting interval. req:%lu, idx: %d, val: %d",
617 val, idx, stts751_intervals[idx]);
618
619 mutex_lock(&priv->access_lock);
620 if (priv->interval == idx)
621 goto exit;
622
623 /*
624 * In early development stages I've become suspicious about the chip
625 * starting to misbehave if I ever set, even briefly, an invalid
626 * configuration. While I'm not sure this is really needed, be
627 * conservative and set rate/resolution in such an order that avoids
628 * passing through an invalid configuration.
629 */
630
631 /* speed up: lower the resolution, then modify convrate */
632 if (priv->interval < idx) {
633 dev_dbg(&priv->client->dev, "lower resolution, then modify convrate");
634 priv->interval = idx;
635 ret = stts751_adjust_resolution(priv);
636 if (ret)
637 goto exit;
638 }
639
640 ret = i2c_smbus_write_byte_data(priv->client, STTS751_REG_RATE, idx);
641 if (ret)
642 goto exit;
643 /* slow down: modify convrate, then raise resolution */
644 if (priv->interval != idx) {
645 dev_dbg(&priv->client->dev, "modify convrate, then raise resolution");
646 priv->interval = idx;
647 ret = stts751_adjust_resolution(priv);
648 if (ret)
649 goto exit;
650 }
651 ret = count;
652exit:
653 mutex_unlock(&priv->access_lock);
654
655 return ret;
656}
657
658static int stts751_detect(struct i2c_client *new_client,
659 struct i2c_board_info *info)
660{
661 struct i2c_adapter *adapter = new_client->adapter;
662 const char *name;
663 int tmp;
664
665 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
666 return -ENODEV;
667
668 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_MAN_ID);
669 if (tmp != ST_MAN_ID)
670 return -ENODEV;
671
672 /* lower temperaure registers always have bits 0-3 set to zero */
673 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_TEMP_L);
674 if (tmp & 0xf)
675 return -ENODEV;
676
677 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_HLIM_L);
678 if (tmp & 0xf)
679 return -ENODEV;
680
681 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_LLIM_L);
682 if (tmp & 0xf)
683 return -ENODEV;
684
685 /* smbus timeout register always have bits 0-7 set to zero */
686 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_SMBUS_TO);
687 if (tmp & 0x7f)
688 return -ENODEV;
689
690 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID);
691
692 switch (tmp) {
693 case STTS751_0_PROD_ID:
694 name = "STTS751-0";
695 break;
696 case STTS751_1_PROD_ID:
697 name = "STTS751-1";
698 break;
699 default:
700 return -ENODEV;
701 }
702 dev_dbg(&new_client->dev, "Chip %s detected", name);
703
704 strlcpy(info->type, stts751_id[0].name, I2C_NAME_SIZE);
705 return 0;
706}
707
708static int stts751_read_chip_config(struct stts751_priv *priv)
709{
710 int ret;
711 int tmp;
712
713 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_CONF);
714 if (ret < 0)
715 return ret;
716 priv->config = ret;
717 priv->res = (ret & STTS751_CONF_RES_MASK) >> STTS751_CONF_RES_SHIFT;
718
719 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE);
720 if (ret < 0)
721 return ret;
722 if (ret >= ARRAY_SIZE(stts751_intervals)) {
723 dev_err(priv->dev, "Unrecognized conversion rate 0x%x\n", ret);
724 return -ENODEV;
725 }
726 priv->interval = ret;
727
728 ret = stts751_read_reg16(priv, &priv->event_max,
729 STTS751_REG_HLIM_H, STTS751_REG_HLIM_L);
730 if (ret)
731 return ret;
732
733 ret = stts751_read_reg16(priv, &priv->event_min,
734 STTS751_REG_LLIM_H, STTS751_REG_LLIM_L);
735 if (ret)
736 return ret;
737
738 ret = stts751_read_reg8(priv, &priv->therm, STTS751_REG_TLIM);
739 if (ret)
740 return ret;
741
742 ret = stts751_read_reg8(priv, &tmp, STTS751_REG_HYST);
743 if (ret)
744 return ret;
745 priv->hyst = priv->therm - tmp;
746
747 return 0;
748}
749
750static SENSOR_DEVICE_ATTR_RO(temp1_input, input, 0);
751static SENSOR_DEVICE_ATTR_RW(temp1_min, min, 0);
752static SENSOR_DEVICE_ATTR_RW(temp1_max, max, 0);
753static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, min_alarm, 0);
754static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, max_alarm, 0);
755static SENSOR_DEVICE_ATTR_RW(temp1_crit, therm, 0);
756static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, hyst, 0);
757static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, therm_trip, 0);
758static SENSOR_DEVICE_ATTR_RW(update_interval, interval, 0);
759
760static struct attribute *stts751_attrs[] = {
761 &sensor_dev_attr_temp1_input.dev_attr.attr,
762 &sensor_dev_attr_temp1_min.dev_attr.attr,
763 &sensor_dev_attr_temp1_max.dev_attr.attr,
764 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
765 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
766 &sensor_dev_attr_temp1_crit.dev_attr.attr,
767 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
768 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
769 &sensor_dev_attr_update_interval.dev_attr.attr,
770 NULL
771};
772ATTRIBUTE_GROUPS(stts751);
773
774static int stts751_probe(struct i2c_client *client,
775 const struct i2c_device_id *id)
776{
777 struct stts751_priv *priv;
778 int ret;
779 bool smbus_nto;
780 int rev_id;
781
782 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
783 if (!priv)
784 return -ENOMEM;
785
786 priv->client = client;
787 priv->notify_max = true;
788 priv->notify_min = true;
789 i2c_set_clientdata(client, priv);
790 mutex_init(&priv->access_lock);
791
792 if (device_property_present(&client->dev,
793 "smbus-timeout-disable")) {
794 smbus_nto = device_property_read_bool(&client->dev,
795 "smbus-timeout-disable");
796
797 ret = i2c_smbus_write_byte_data(client, STTS751_REG_SMBUS_TO,
798 smbus_nto ? 0 : 0x80);
799 if (ret)
800 return ret;
801 }
802
803 rev_id = i2c_smbus_read_byte_data(client, STTS751_REG_REV_ID);
804 if (rev_id < 0)
805 return -ENODEV;
806 if (rev_id != 0x1) {
807 dev_dbg(&client->dev, "Chip revision 0x%x is untested\n",
808 rev_id);
809 }
810
811 ret = stts751_read_chip_config(priv);
812 if (ret)
813 return ret;
814
815 priv->config &= ~(STTS751_CONF_STOP | STTS751_CONF_EVENT_DIS);
816 ret = i2c_smbus_write_byte_data(client, STTS751_REG_CONF, priv->config);
817 if (ret)
818 return ret;
819
820 priv->dev = devm_hwmon_device_register_with_groups(&client->dev,
821 client->name, priv,
822 stts751_groups);
823 return PTR_ERR_OR_ZERO(priv->dev);
824}
825
826MODULE_DEVICE_TABLE(i2c, stts751_id);
827
828static struct i2c_driver stts751_driver = {
829 .class = I2C_CLASS_HWMON,
830 .driver = {
831 .name = DEVNAME,
832 .of_match_table = of_match_ptr(stts751_of_match),
833 },
834 .probe = stts751_probe,
835 .id_table = stts751_id,
836 .detect = stts751_detect,
837 .alert = stts751_alert,
838 .address_list = normal_i2c,
839};
840
841module_i2c_driver(stts751_driver);
842
843MODULE_AUTHOR("Andrea Merello <andrea.merello@gmail.com>");
844MODULE_DESCRIPTION("STTS751 sensor driver");
845MODULE_LICENSE("GPL");
846