1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * STTS751 sensor driver
4 *
5 * Copyright (C) 2016-2017 Istituto Italiano di Tecnologia - RBCS - EDL
6 * Robotics, Brain and Cognitive Sciences department
7 * Electronic Design Laboratory
8 *
9 * Written by Andrea Merello <andrea.merello@gmail.com>
10 *
11 * Based on LM95241 driver and LM90 driver
12 */
13
14 #include <linux/bitops.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/interrupt.h>
21 #include <linux/jiffies.h>
22 #include <linux/module.h>
23 #include <linux/mutex.h>
24 #include <linux/property.h>
25 #include <linux/slab.h>
26 #include <linux/sysfs.h>
27 #include <linux/util_macros.h>
28
29 #define DEVNAME "stts751"
30
31 static const unsigned short normal_i2c[] = {
32 0x48, 0x49, 0x38, 0x39, /* STTS751-0 */
33 0x4A, 0x4B, 0x3A, 0x3B, /* STTS751-1 */
34 I2C_CLIENT_END };
35
36 #define STTS751_REG_TEMP_H 0x00
37 #define STTS751_REG_STATUS 0x01
38 #define STTS751_STATUS_TRIPT BIT(0)
39 #define STTS751_STATUS_TRIPL BIT(5)
40 #define STTS751_STATUS_TRIPH BIT(6)
41 #define STTS751_REG_TEMP_L 0x02
42 #define STTS751_REG_CONF 0x03
43 #define STTS751_CONF_RES_MASK 0x0C
44 #define STTS751_CONF_RES_SHIFT 2
45 #define STTS751_CONF_EVENT_DIS BIT(7)
46 #define STTS751_CONF_STOP BIT(6)
47 #define STTS751_REG_RATE 0x04
48 #define STTS751_REG_HLIM_H 0x05
49 #define STTS751_REG_HLIM_L 0x06
50 #define STTS751_REG_LLIM_H 0x07
51 #define STTS751_REG_LLIM_L 0x08
52 #define STTS751_REG_TLIM 0x20
53 #define STTS751_REG_HYST 0x21
54 #define STTS751_REG_SMBUS_TO 0x22
55
56 #define STTS751_REG_PROD_ID 0xFD
57 #define STTS751_REG_MAN_ID 0xFE
58 #define STTS751_REG_REV_ID 0xFF
59
60 #define STTS751_0_PROD_ID 0x00
61 #define STTS751_1_PROD_ID 0x01
62 #define ST_MAN_ID 0x53
63
64 /*
65 * Possible update intervals are (in mS):
66 * 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 62.5, 31.25
67 * However we are not going to complicate things too much and we stick to the
68 * approx value in mS.
69 */
70 static const int stts751_intervals[] = {
71 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 63, 31
72 };
73
74 static const struct i2c_device_id stts751_id[] = {
75 { "stts751" },
76 { }
77 };
78
79 static const struct of_device_id __maybe_unused stts751_of_match[] = {
80 { .compatible = "st,stts751" },
81 { },
82 };
83 MODULE_DEVICE_TABLE(of, stts751_of_match);
84
85 struct stts751_priv {
86 struct device *dev;
87 struct i2c_client *client;
88 struct mutex access_lock;
89 u8 interval;
90 int res;
91 int event_max, event_min;
92 int therm;
93 int hyst;
94 int temp;
95 unsigned long last_update, last_alert_update;
96 u8 config;
97 bool min_alert, max_alert, therm_trip;
98 bool data_valid, alert_valid;
99 bool notify_max, notify_min;
100 };
101
102 /*
103 * These functions converts temperature from HW format to integer format and
104 * vice-vers. They are (mostly) taken from lm90 driver. Unit is in mC.
105 */
stts751_to_deg(s16 hw_val)106 static int stts751_to_deg(s16 hw_val)
107 {
108 return hw_val * 125 / 32;
109 }
110
stts751_to_hw(int val)111 static s32 stts751_to_hw(int val)
112 {
113 return DIV_ROUND_CLOSEST(val, 125) * 32;
114 }
115
stts751_adjust_resolution(struct stts751_priv * priv)116 static int stts751_adjust_resolution(struct stts751_priv *priv)
117 {
118 u8 res;
119
120 switch (priv->interval) {
121 case 9:
122 /* 10 bits */
123 res = 0;
124 break;
125 case 8:
126 /* 11 bits */
127 res = 1;
128 break;
129 default:
130 /* 12 bits */
131 res = 3;
132 break;
133 }
134
135 if (priv->res == res)
136 return 0;
137
138 priv->config &= ~STTS751_CONF_RES_MASK;
139 priv->config |= res << STTS751_CONF_RES_SHIFT;
140 dev_dbg(&priv->client->dev, "setting res %d. config %x",
141 res, priv->config);
142 priv->res = res;
143
144 return i2c_smbus_write_byte_data(priv->client,
145 STTS751_REG_CONF, priv->config);
146 }
147
stts751_update_temp(struct stts751_priv * priv)148 static int stts751_update_temp(struct stts751_priv *priv)
149 {
150 s32 integer1, integer2, frac;
151
152 /*
153 * There is a trick here, like in the lm90 driver. We have to read two
154 * registers to get the sensor temperature, but we have to beware a
155 * conversion could occur between the readings. We could use the
156 * one-shot conversion register, but we don't want to do this (disables
157 * hardware monitoring). So the solution used here is to read the high
158 * byte once, then the low byte, then the high byte again. If the new
159 * high byte matches the old one, then we have a valid reading. Else we
160 * have to read the low byte again, and now we believe we have a correct
161 * reading.
162 */
163 integer1 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H);
164 if (integer1 < 0) {
165 dev_dbg(&priv->client->dev,
166 "I2C read failed (temp H). ret: %x\n", integer1);
167 return integer1;
168 }
169
170 frac = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_L);
171 if (frac < 0) {
172 dev_dbg(&priv->client->dev,
173 "I2C read failed (temp L). ret: %x\n", frac);
174 return frac;
175 }
176
177 integer2 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H);
178 if (integer2 < 0) {
179 dev_dbg(&priv->client->dev,
180 "I2C 2nd read failed (temp H). ret: %x\n", integer2);
181 return integer2;
182 }
183
184 if (integer1 != integer2) {
185 frac = i2c_smbus_read_byte_data(priv->client,
186 STTS751_REG_TEMP_L);
187 if (frac < 0) {
188 dev_dbg(&priv->client->dev,
189 "I2C 2nd read failed (temp L). ret: %x\n",
190 frac);
191 return frac;
192 }
193 }
194
195 priv->temp = stts751_to_deg((integer1 << 8) | frac);
196 return 0;
197 }
198
stts751_set_temp_reg16(struct stts751_priv * priv,int temp,u8 hreg,u8 lreg)199 static int stts751_set_temp_reg16(struct stts751_priv *priv, int temp,
200 u8 hreg, u8 lreg)
201 {
202 s32 hwval;
203 int ret;
204
205 hwval = stts751_to_hw(temp);
206
207 ret = i2c_smbus_write_byte_data(priv->client, hreg, hwval >> 8);
208 if (ret)
209 return ret;
210
211 return i2c_smbus_write_byte_data(priv->client, lreg, hwval & 0xff);
212 }
213
stts751_set_temp_reg8(struct stts751_priv * priv,int temp,u8 reg)214 static int stts751_set_temp_reg8(struct stts751_priv *priv, int temp, u8 reg)
215 {
216 s32 hwval;
217
218 hwval = stts751_to_hw(temp);
219 return i2c_smbus_write_byte_data(priv->client, reg, hwval >> 8);
220 }
221
stts751_read_reg16(struct stts751_priv * priv,int * temp,u8 hreg,u8 lreg)222 static int stts751_read_reg16(struct stts751_priv *priv, int *temp,
223 u8 hreg, u8 lreg)
224 {
225 int integer, frac;
226
227 integer = i2c_smbus_read_byte_data(priv->client, hreg);
228 if (integer < 0)
229 return integer;
230
231 frac = i2c_smbus_read_byte_data(priv->client, lreg);
232 if (frac < 0)
233 return frac;
234
235 *temp = stts751_to_deg((integer << 8) | frac);
236
237 return 0;
238 }
239
stts751_read_reg8(struct stts751_priv * priv,int * temp,u8 reg)240 static int stts751_read_reg8(struct stts751_priv *priv, int *temp, u8 reg)
241 {
242 int integer;
243
244 integer = i2c_smbus_read_byte_data(priv->client, reg);
245 if (integer < 0)
246 return integer;
247
248 *temp = stts751_to_deg(integer << 8);
249
250 return 0;
251 }
252
253 /*
254 * Update alert flags without waiting for cache to expire. We detects alerts
255 * immediately for the sake of the alert handler; we still need to deal with
256 * caching to workaround the fact that alarm flags int the status register,
257 * despite what the datasheet claims, gets always cleared on read.
258 */
stts751_update_alert(struct stts751_priv * priv)259 static int stts751_update_alert(struct stts751_priv *priv)
260 {
261 int ret;
262 bool conv_done;
263 int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]);
264
265 /*
266 * Add another 10% because if we run faster than the HW conversion
267 * rate we will end up in reporting incorrectly alarms.
268 */
269 cache_time += cache_time / 10;
270
271 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_STATUS);
272 if (ret < 0)
273 return ret;
274
275 dev_dbg(&priv->client->dev, "status reg %x\n", ret);
276 conv_done = ret & (STTS751_STATUS_TRIPH | STTS751_STATUS_TRIPL);
277 /*
278 * Reset the cache if the cache time expired, or if we are sure
279 * we have valid data from a device conversion, or if we know
280 * our cache has been never written.
281 *
282 * Note that when the cache has been never written the point is
283 * to correctly initialize the timestamp, rather than clearing
284 * the cache values.
285 *
286 * Note that updating the cache timestamp when we get an alarm flag
287 * is required, otherwise we could incorrectly report alarms to be zero.
288 */
289 if (time_after(jiffies, priv->last_alert_update + cache_time) ||
290 conv_done || !priv->alert_valid) {
291 priv->max_alert = false;
292 priv->min_alert = false;
293 priv->alert_valid = true;
294 priv->last_alert_update = jiffies;
295 dev_dbg(&priv->client->dev, "invalidating alert cache\n");
296 }
297
298 priv->max_alert |= !!(ret & STTS751_STATUS_TRIPH);
299 priv->min_alert |= !!(ret & STTS751_STATUS_TRIPL);
300 priv->therm_trip = !!(ret & STTS751_STATUS_TRIPT);
301
302 dev_dbg(&priv->client->dev, "max_alert: %d, min_alert: %d, therm_trip: %d\n",
303 priv->max_alert, priv->min_alert, priv->therm_trip);
304
305 return 0;
306 }
307
stts751_alert(struct i2c_client * client,enum i2c_alert_protocol type,unsigned int data)308 static void stts751_alert(struct i2c_client *client,
309 enum i2c_alert_protocol type, unsigned int data)
310 {
311 int ret;
312 struct stts751_priv *priv = i2c_get_clientdata(client);
313
314 if (type != I2C_PROTOCOL_SMBUS_ALERT)
315 return;
316
317 dev_dbg(&client->dev, "alert!");
318
319 mutex_lock(&priv->access_lock);
320 ret = stts751_update_alert(priv);
321 if (ret < 0) {
322 /* default to worst case */
323 priv->max_alert = true;
324 priv->min_alert = true;
325
326 dev_warn(priv->dev,
327 "Alert received, but can't communicate to the device. Triggering all alarms!");
328 }
329
330 if (priv->max_alert) {
331 if (priv->notify_max)
332 dev_notice(priv->dev, "got alert for HIGH temperature");
333 priv->notify_max = false;
334
335 /* unblock alert poll */
336 sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm");
337 }
338
339 if (priv->min_alert) {
340 if (priv->notify_min)
341 dev_notice(priv->dev, "got alert for LOW temperature");
342 priv->notify_min = false;
343
344 /* unblock alert poll */
345 sysfs_notify(&priv->dev->kobj, NULL, "temp1_min_alarm");
346 }
347
348 if (priv->min_alert || priv->max_alert)
349 kobject_uevent(&priv->dev->kobj, KOBJ_CHANGE);
350
351 mutex_unlock(&priv->access_lock);
352 }
353
stts751_update(struct stts751_priv * priv)354 static int stts751_update(struct stts751_priv *priv)
355 {
356 int ret;
357 int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]);
358
359 if (time_after(jiffies, priv->last_update + cache_time) ||
360 !priv->data_valid) {
361 ret = stts751_update_temp(priv);
362 if (ret)
363 return ret;
364
365 ret = stts751_update_alert(priv);
366 if (ret)
367 return ret;
368 priv->data_valid = true;
369 priv->last_update = jiffies;
370 }
371
372 return 0;
373 }
374
max_alarm_show(struct device * dev,struct device_attribute * attr,char * buf)375 static ssize_t max_alarm_show(struct device *dev,
376 struct device_attribute *attr, char *buf)
377 {
378 int ret;
379 struct stts751_priv *priv = dev_get_drvdata(dev);
380
381 mutex_lock(&priv->access_lock);
382 ret = stts751_update(priv);
383 if (!ret)
384 priv->notify_max = true;
385 mutex_unlock(&priv->access_lock);
386 if (ret < 0)
387 return ret;
388
389 return sysfs_emit(buf, "%d\n", priv->max_alert);
390 }
391
min_alarm_show(struct device * dev,struct device_attribute * attr,char * buf)392 static ssize_t min_alarm_show(struct device *dev,
393 struct device_attribute *attr, char *buf)
394 {
395 int ret;
396 struct stts751_priv *priv = dev_get_drvdata(dev);
397
398 mutex_lock(&priv->access_lock);
399 ret = stts751_update(priv);
400 if (!ret)
401 priv->notify_min = true;
402 mutex_unlock(&priv->access_lock);
403 if (ret < 0)
404 return ret;
405
406 return sysfs_emit(buf, "%d\n", priv->min_alert);
407 }
408
input_show(struct device * dev,struct device_attribute * attr,char * buf)409 static ssize_t input_show(struct device *dev, struct device_attribute *attr,
410 char *buf)
411 {
412 int ret;
413 struct stts751_priv *priv = dev_get_drvdata(dev);
414
415 mutex_lock(&priv->access_lock);
416 ret = stts751_update(priv);
417 mutex_unlock(&priv->access_lock);
418 if (ret < 0)
419 return ret;
420
421 return sysfs_emit(buf, "%d\n", priv->temp);
422 }
423
therm_show(struct device * dev,struct device_attribute * attr,char * buf)424 static ssize_t therm_show(struct device *dev, struct device_attribute *attr,
425 char *buf)
426 {
427 struct stts751_priv *priv = dev_get_drvdata(dev);
428
429 return sysfs_emit(buf, "%d\n", priv->therm);
430 }
431
therm_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)432 static ssize_t therm_store(struct device *dev, struct device_attribute *attr,
433 const char *buf, size_t count)
434 {
435 int ret;
436 long temp;
437 struct stts751_priv *priv = dev_get_drvdata(dev);
438
439 if (kstrtol(buf, 10, &temp) < 0)
440 return -EINVAL;
441
442 /* HW works in range -64C to +127.937C */
443 temp = clamp_val(temp, -64000, 127937);
444 mutex_lock(&priv->access_lock);
445 ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_TLIM);
446 if (ret)
447 goto exit;
448
449 dev_dbg(&priv->client->dev, "setting therm %ld", temp);
450
451 /*
452 * hysteresis reg is relative to therm, so the HW does not need to be
453 * adjusted, we need to update our local copy only.
454 */
455 priv->hyst = temp - (priv->therm - priv->hyst);
456 priv->therm = temp;
457
458 exit:
459 mutex_unlock(&priv->access_lock);
460 if (ret)
461 return ret;
462
463 return count;
464 }
465
hyst_show(struct device * dev,struct device_attribute * attr,char * buf)466 static ssize_t hyst_show(struct device *dev, struct device_attribute *attr,
467 char *buf)
468 {
469 struct stts751_priv *priv = dev_get_drvdata(dev);
470
471 return sysfs_emit(buf, "%d\n", priv->hyst);
472 }
473
hyst_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)474 static ssize_t hyst_store(struct device *dev, struct device_attribute *attr,
475 const char *buf, size_t count)
476 {
477 int ret;
478 long temp;
479
480 struct stts751_priv *priv = dev_get_drvdata(dev);
481
482 if (kstrtol(buf, 10, &temp) < 0)
483 return -EINVAL;
484
485 mutex_lock(&priv->access_lock);
486 /* HW works in range -64C to +127.937C */
487 temp = clamp_val(temp, -64000, priv->therm);
488 priv->hyst = temp;
489 dev_dbg(&priv->client->dev, "setting hyst %ld", temp);
490 temp = priv->therm - temp;
491 ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_HYST);
492 mutex_unlock(&priv->access_lock);
493 if (ret)
494 return ret;
495
496 return count;
497 }
498
therm_trip_show(struct device * dev,struct device_attribute * attr,char * buf)499 static ssize_t therm_trip_show(struct device *dev,
500 struct device_attribute *attr, char *buf)
501 {
502 int ret;
503 struct stts751_priv *priv = dev_get_drvdata(dev);
504
505 mutex_lock(&priv->access_lock);
506 ret = stts751_update(priv);
507 mutex_unlock(&priv->access_lock);
508 if (ret < 0)
509 return ret;
510
511 return sysfs_emit(buf, "%d\n", priv->therm_trip);
512 }
513
max_show(struct device * dev,struct device_attribute * attr,char * buf)514 static ssize_t max_show(struct device *dev, struct device_attribute *attr,
515 char *buf)
516 {
517 struct stts751_priv *priv = dev_get_drvdata(dev);
518
519 return sysfs_emit(buf, "%d\n", priv->event_max);
520 }
521
max_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)522 static ssize_t max_store(struct device *dev, struct device_attribute *attr,
523 const char *buf, size_t count)
524 {
525 int ret;
526 long temp;
527 struct stts751_priv *priv = dev_get_drvdata(dev);
528
529 if (kstrtol(buf, 10, &temp) < 0)
530 return -EINVAL;
531
532 mutex_lock(&priv->access_lock);
533 /* HW works in range -64C to +127.937C */
534 temp = clamp_val(temp, priv->event_min, 127937);
535 ret = stts751_set_temp_reg16(priv, temp,
536 STTS751_REG_HLIM_H, STTS751_REG_HLIM_L);
537 if (ret)
538 goto exit;
539
540 dev_dbg(&priv->client->dev, "setting event max %ld", temp);
541 priv->event_max = temp;
542 ret = count;
543 exit:
544 mutex_unlock(&priv->access_lock);
545 return ret;
546 }
547
min_show(struct device * dev,struct device_attribute * attr,char * buf)548 static ssize_t min_show(struct device *dev, struct device_attribute *attr,
549 char *buf)
550 {
551 struct stts751_priv *priv = dev_get_drvdata(dev);
552
553 return sysfs_emit(buf, "%d\n", priv->event_min);
554 }
555
min_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)556 static ssize_t min_store(struct device *dev, struct device_attribute *attr,
557 const char *buf, size_t count)
558 {
559 int ret;
560 long temp;
561 struct stts751_priv *priv = dev_get_drvdata(dev);
562
563 if (kstrtol(buf, 10, &temp) < 0)
564 return -EINVAL;
565
566 mutex_lock(&priv->access_lock);
567 /* HW works in range -64C to +127.937C */
568 temp = clamp_val(temp, -64000, priv->event_max);
569 ret = stts751_set_temp_reg16(priv, temp,
570 STTS751_REG_LLIM_H, STTS751_REG_LLIM_L);
571 if (ret)
572 goto exit;
573
574 dev_dbg(&priv->client->dev, "setting event min %ld", temp);
575 priv->event_min = temp;
576 ret = count;
577 exit:
578 mutex_unlock(&priv->access_lock);
579 return ret;
580 }
581
interval_show(struct device * dev,struct device_attribute * attr,char * buf)582 static ssize_t interval_show(struct device *dev,
583 struct device_attribute *attr, char *buf)
584 {
585 struct stts751_priv *priv = dev_get_drvdata(dev);
586
587 return sysfs_emit(buf, "%d\n",
588 stts751_intervals[priv->interval]);
589 }
590
interval_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)591 static ssize_t interval_store(struct device *dev,
592 struct device_attribute *attr, const char *buf,
593 size_t count)
594 {
595 unsigned long val;
596 int idx;
597 int ret = count;
598 struct stts751_priv *priv = dev_get_drvdata(dev);
599
600 if (kstrtoul(buf, 10, &val) < 0)
601 return -EINVAL;
602
603 idx = find_closest_descending(val, stts751_intervals,
604 ARRAY_SIZE(stts751_intervals));
605
606 dev_dbg(&priv->client->dev, "setting interval. req:%lu, idx: %d, val: %d",
607 val, idx, stts751_intervals[idx]);
608
609 mutex_lock(&priv->access_lock);
610 if (priv->interval == idx)
611 goto exit;
612
613 /*
614 * In early development stages I've become suspicious about the chip
615 * starting to misbehave if I ever set, even briefly, an invalid
616 * configuration. While I'm not sure this is really needed, be
617 * conservative and set rate/resolution in such an order that avoids
618 * passing through an invalid configuration.
619 */
620
621 /* speed up: lower the resolution, then modify convrate */
622 if (priv->interval < idx) {
623 dev_dbg(&priv->client->dev, "lower resolution, then modify convrate");
624 priv->interval = idx;
625 ret = stts751_adjust_resolution(priv);
626 if (ret)
627 goto exit;
628 }
629
630 ret = i2c_smbus_write_byte_data(priv->client, STTS751_REG_RATE, idx);
631 if (ret)
632 goto exit;
633 /* slow down: modify convrate, then raise resolution */
634 if (priv->interval != idx) {
635 dev_dbg(&priv->client->dev, "modify convrate, then raise resolution");
636 priv->interval = idx;
637 ret = stts751_adjust_resolution(priv);
638 if (ret)
639 goto exit;
640 }
641 ret = count;
642 exit:
643 mutex_unlock(&priv->access_lock);
644
645 return ret;
646 }
647
stts751_detect(struct i2c_client * new_client,struct i2c_board_info * info)648 static int stts751_detect(struct i2c_client *new_client,
649 struct i2c_board_info *info)
650 {
651 struct i2c_adapter *adapter = new_client->adapter;
652 const char *name;
653 int tmp;
654
655 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
656 return -ENODEV;
657
658 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_MAN_ID);
659 if (tmp != ST_MAN_ID)
660 return -ENODEV;
661
662 /* lower temperaure registers always have bits 0-3 set to zero */
663 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_TEMP_L);
664 if (tmp & 0xf)
665 return -ENODEV;
666
667 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_HLIM_L);
668 if (tmp & 0xf)
669 return -ENODEV;
670
671 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_LLIM_L);
672 if (tmp & 0xf)
673 return -ENODEV;
674
675 /* smbus timeout register always have bits 0-7 set to zero */
676 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_SMBUS_TO);
677 if (tmp & 0x7f)
678 return -ENODEV;
679
680 tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID);
681
682 switch (tmp) {
683 case STTS751_0_PROD_ID:
684 name = "STTS751-0";
685 break;
686 case STTS751_1_PROD_ID:
687 name = "STTS751-1";
688 break;
689 default:
690 return -ENODEV;
691 }
692 dev_dbg(&new_client->dev, "Chip %s detected", name);
693
694 strscpy(info->type, stts751_id[0].name, I2C_NAME_SIZE);
695 return 0;
696 }
697
stts751_read_chip_config(struct stts751_priv * priv)698 static int stts751_read_chip_config(struct stts751_priv *priv)
699 {
700 int ret;
701 int tmp;
702
703 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_CONF);
704 if (ret < 0)
705 return ret;
706 priv->config = ret;
707 priv->res = (ret & STTS751_CONF_RES_MASK) >> STTS751_CONF_RES_SHIFT;
708
709 ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE);
710 if (ret < 0)
711 return ret;
712 if (ret >= ARRAY_SIZE(stts751_intervals)) {
713 dev_err(priv->dev, "Unrecognized conversion rate 0x%x\n", ret);
714 return -ENODEV;
715 }
716 priv->interval = ret;
717
718 ret = stts751_read_reg16(priv, &priv->event_max,
719 STTS751_REG_HLIM_H, STTS751_REG_HLIM_L);
720 if (ret)
721 return ret;
722
723 ret = stts751_read_reg16(priv, &priv->event_min,
724 STTS751_REG_LLIM_H, STTS751_REG_LLIM_L);
725 if (ret)
726 return ret;
727
728 ret = stts751_read_reg8(priv, &priv->therm, STTS751_REG_TLIM);
729 if (ret)
730 return ret;
731
732 ret = stts751_read_reg8(priv, &tmp, STTS751_REG_HYST);
733 if (ret)
734 return ret;
735 priv->hyst = priv->therm - tmp;
736
737 return 0;
738 }
739
740 static SENSOR_DEVICE_ATTR_RO(temp1_input, input, 0);
741 static SENSOR_DEVICE_ATTR_RW(temp1_min, min, 0);
742 static SENSOR_DEVICE_ATTR_RW(temp1_max, max, 0);
743 static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, min_alarm, 0);
744 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, max_alarm, 0);
745 static SENSOR_DEVICE_ATTR_RW(temp1_crit, therm, 0);
746 static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, hyst, 0);
747 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, therm_trip, 0);
748 static SENSOR_DEVICE_ATTR_RW(update_interval, interval, 0);
749
750 static struct attribute *stts751_attrs[] = {
751 &sensor_dev_attr_temp1_input.dev_attr.attr,
752 &sensor_dev_attr_temp1_min.dev_attr.attr,
753 &sensor_dev_attr_temp1_max.dev_attr.attr,
754 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
755 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
756 &sensor_dev_attr_temp1_crit.dev_attr.attr,
757 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
758 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
759 &sensor_dev_attr_update_interval.dev_attr.attr,
760 NULL
761 };
762 ATTRIBUTE_GROUPS(stts751);
763
stts751_probe(struct i2c_client * client)764 static int stts751_probe(struct i2c_client *client)
765 {
766 struct stts751_priv *priv;
767 int ret;
768 bool smbus_nto;
769 int rev_id;
770
771 priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL);
772 if (!priv)
773 return -ENOMEM;
774
775 priv->client = client;
776 priv->notify_max = true;
777 priv->notify_min = true;
778 i2c_set_clientdata(client, priv);
779 mutex_init(&priv->access_lock);
780
781 if (device_property_present(&client->dev,
782 "smbus-timeout-disable")) {
783 smbus_nto = device_property_read_bool(&client->dev,
784 "smbus-timeout-disable");
785
786 ret = i2c_smbus_write_byte_data(client, STTS751_REG_SMBUS_TO,
787 smbus_nto ? 0 : 0x80);
788 if (ret)
789 return ret;
790 }
791
792 rev_id = i2c_smbus_read_byte_data(client, STTS751_REG_REV_ID);
793 if (rev_id < 0)
794 return -ENODEV;
795 if (rev_id != 0x1) {
796 dev_dbg(&client->dev, "Chip revision 0x%x is untested\n",
797 rev_id);
798 }
799
800 ret = stts751_read_chip_config(priv);
801 if (ret)
802 return ret;
803
804 priv->config &= ~(STTS751_CONF_STOP | STTS751_CONF_EVENT_DIS);
805 ret = i2c_smbus_write_byte_data(client, STTS751_REG_CONF, priv->config);
806 if (ret)
807 return ret;
808
809 priv->dev = devm_hwmon_device_register_with_groups(&client->dev,
810 client->name, priv,
811 stts751_groups);
812 return PTR_ERR_OR_ZERO(priv->dev);
813 }
814
815 MODULE_DEVICE_TABLE(i2c, stts751_id);
816
817 static struct i2c_driver stts751_driver = {
818 .class = I2C_CLASS_HWMON,
819 .driver = {
820 .name = DEVNAME,
821 .of_match_table = of_match_ptr(stts751_of_match),
822 },
823 .probe = stts751_probe,
824 .id_table = stts751_id,
825 .detect = stts751_detect,
826 .alert = stts751_alert,
827 .address_list = normal_i2c,
828 };
829
830 module_i2c_driver(stts751_driver);
831
832 MODULE_AUTHOR("Andrea Merello <andrea.merello@gmail.com>");
833 MODULE_DESCRIPTION("STTS751 sensor driver");
834 MODULE_LICENSE("GPL");
835