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7f07ec0f | 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 | ||
40 | static 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 | */ | |
79 | static const int stts751_intervals[] = { | |
80 | 16000, 8000, 4000, 2000, 1000, 500, 250, 125, 63, 31 | |
81 | }; | |
82 | ||
83 | static const struct i2c_device_id stts751_id[] = { | |
84 | { "stts751", 0 }, | |
85 | { } | |
86 | }; | |
87 | ||
1c1a7b75 JMC |
88 | static const struct of_device_id stts751_of_match[] = { |
89 | { .compatible = "stts751" }, | |
90 | { }, | |
91 | }; | |
92 | MODULE_DEVICE_TABLE(of, stts751_of_match); | |
93 | ||
7f07ec0f | 94 | struct 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 | */ | |
116 | static int stts751_to_deg(s16 hw_val) | |
117 | { | |
118 | return hw_val * 125 / 32; | |
119 | } | |
120 | ||
121 | static s32 stts751_to_hw(int val) | |
122 | { | |
123 | return DIV_ROUND_CLOSEST(val, 125) * 32; | |
124 | } | |
125 | ||
126 | static 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 | ||
158 | static 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 | ||
209 | static 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 | ||
224 | static 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 | ||
232 | static 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 | ||
250 | static 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 | */ | |
269 | static 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 | ||
318 | static 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 | ||
364 | static 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 | ||
385 | static ssize_t show_max_alarm(struct device *dev, struct device_attribute *attr, | |
386 | 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 - 1, "%d\n", priv->max_alert); | |
400 | } | |
401 | ||
402 | static ssize_t show_min_alarm(struct device *dev, struct device_attribute *attr, | |
403 | 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 - 1, "%d\n", priv->min_alert); | |
417 | } | |
418 | ||
419 | static ssize_t show_input(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 - 1, "%d\n", priv->temp); | |
432 | } | |
433 | ||
434 | static ssize_t show_therm(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 - 1, "%d\n", priv->therm); | |
440 | } | |
441 | ||
442 | static ssize_t set_therm(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 | ||
468 | exit: | |
469 | mutex_unlock(&priv->access_lock); | |
470 | if (ret) | |
471 | return ret; | |
472 | ||
473 | return count; | |
474 | } | |
475 | ||
476 | static ssize_t show_hyst(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 - 1, "%d\n", priv->hyst); | |
482 | } | |
483 | ||
484 | static ssize_t set_hyst(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 | ||
509 | static ssize_t show_therm_trip(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 - 1, "%d\n", priv->therm_trip); | |
522 | } | |
523 | ||
524 | static ssize_t show_max(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 - 1, "%d\n", priv->event_max); | |
530 | } | |
531 | ||
532 | static ssize_t set_max(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; | |
553 | exit: | |
554 | mutex_unlock(&priv->access_lock); | |
555 | return ret; | |
556 | } | |
557 | ||
558 | static ssize_t show_min(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 - 1, "%d\n", priv->event_min); | |
564 | } | |
565 | ||
566 | static ssize_t set_min(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; | |
587 | exit: | |
588 | mutex_unlock(&priv->access_lock); | |
589 | return ret; | |
590 | } | |
591 | ||
592 | static ssize_t show_interval(struct device *dev, struct device_attribute *attr, | |
593 | char *buf) | |
594 | { | |
595 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
596 | ||
597 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", | |
598 | stts751_intervals[priv->interval]); | |
599 | } | |
600 | ||
601 | static ssize_t set_interval(struct device *dev, struct device_attribute *attr, | |
602 | const char *buf, size_t count) | |
603 | { | |
604 | unsigned long val; | |
605 | int idx; | |
606 | int ret = count; | |
607 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
608 | ||
609 | if (kstrtoul(buf, 10, &val) < 0) | |
610 | return -EINVAL; | |
611 | ||
612 | idx = find_closest_descending(val, stts751_intervals, | |
613 | ARRAY_SIZE(stts751_intervals)); | |
614 | ||
615 | dev_dbg(&priv->client->dev, "setting interval. req:%lu, idx: %d, val: %d", | |
616 | val, idx, stts751_intervals[idx]); | |
617 | ||
618 | mutex_lock(&priv->access_lock); | |
619 | if (priv->interval == idx) | |
620 | goto exit; | |
621 | ||
622 | /* | |
623 | * In early development stages I've become suspicious about the chip | |
624 | * starting to misbehave if I ever set, even briefly, an invalid | |
625 | * configuration. While I'm not sure this is really needed, be | |
626 | * conservative and set rate/resolution in such an order that avoids | |
627 | * passing through an invalid configuration. | |
628 | */ | |
629 | ||
630 | /* speed up: lower the resolution, then modify convrate */ | |
631 | if (priv->interval < idx) { | |
632 | dev_dbg(&priv->client->dev, "lower resolution, then modify convrate"); | |
633 | priv->interval = idx; | |
634 | ret = stts751_adjust_resolution(priv); | |
635 | if (ret) | |
636 | goto exit; | |
637 | } | |
638 | ||
639 | ret = i2c_smbus_write_byte_data(priv->client, STTS751_REG_RATE, idx); | |
640 | if (ret) | |
641 | goto exit; | |
642 | /* slow down: modify convrate, then raise resolution */ | |
643 | if (priv->interval != idx) { | |
644 | dev_dbg(&priv->client->dev, "modify convrate, then raise resolution"); | |
645 | priv->interval = idx; | |
646 | ret = stts751_adjust_resolution(priv); | |
647 | if (ret) | |
648 | goto exit; | |
649 | } | |
650 | ret = count; | |
651 | exit: | |
652 | mutex_unlock(&priv->access_lock); | |
653 | ||
654 | return ret; | |
655 | } | |
656 | ||
657 | static int stts751_detect(struct i2c_client *new_client, | |
658 | struct i2c_board_info *info) | |
659 | { | |
660 | struct i2c_adapter *adapter = new_client->adapter; | |
661 | const char *name; | |
662 | int tmp; | |
663 | ||
664 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
665 | return -ENODEV; | |
666 | ||
667 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_MAN_ID); | |
668 | if (tmp != ST_MAN_ID) | |
669 | return -ENODEV; | |
670 | ||
671 | /* lower temperaure registers always have bits 0-3 set to zero */ | |
672 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_TEMP_L); | |
673 | if (tmp & 0xf) | |
674 | return -ENODEV; | |
675 | ||
676 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_HLIM_L); | |
677 | if (tmp & 0xf) | |
678 | return -ENODEV; | |
679 | ||
680 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_LLIM_L); | |
681 | if (tmp & 0xf) | |
682 | return -ENODEV; | |
683 | ||
684 | /* smbus timeout register always have bits 0-7 set to zero */ | |
685 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_SMBUS_TO); | |
686 | if (tmp & 0x7f) | |
687 | return -ENODEV; | |
688 | ||
689 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID); | |
690 | ||
691 | switch (tmp) { | |
692 | case STTS751_0_PROD_ID: | |
693 | name = "STTS751-0"; | |
694 | break; | |
695 | case STTS751_1_PROD_ID: | |
696 | name = "STTS751-1"; | |
697 | break; | |
698 | default: | |
699 | return -ENODEV; | |
700 | } | |
701 | dev_dbg(&new_client->dev, "Chip %s detected", name); | |
702 | ||
703 | strlcpy(info->type, stts751_id[0].name, I2C_NAME_SIZE); | |
704 | return 0; | |
705 | } | |
706 | ||
707 | static int stts751_read_chip_config(struct stts751_priv *priv) | |
708 | { | |
709 | int ret; | |
710 | int tmp; | |
711 | ||
712 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_CONF); | |
713 | if (ret < 0) | |
714 | return ret; | |
715 | priv->config = ret; | |
716 | priv->res = (ret & STTS751_CONF_RES_MASK) >> STTS751_CONF_RES_SHIFT; | |
717 | ||
718 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE); | |
719 | if (ret < 0) | |
720 | return ret; | |
721 | priv->interval = ret; | |
722 | ||
723 | ret = stts751_read_reg16(priv, &priv->event_max, | |
724 | STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); | |
725 | if (ret) | |
726 | return ret; | |
727 | ||
728 | ret = stts751_read_reg16(priv, &priv->event_min, | |
729 | STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); | |
730 | if (ret) | |
731 | return ret; | |
732 | ||
733 | ret = stts751_read_reg8(priv, &priv->therm, STTS751_REG_TLIM); | |
734 | if (ret) | |
735 | return ret; | |
736 | ||
737 | ret = stts751_read_reg8(priv, &tmp, STTS751_REG_HYST); | |
738 | if (ret) | |
739 | return ret; | |
740 | priv->hyst = priv->therm - tmp; | |
741 | ||
742 | return 0; | |
743 | } | |
744 | ||
745 | static SENSOR_DEVICE_ATTR(temp1_input, 0444, show_input, NULL, 0); | |
746 | static SENSOR_DEVICE_ATTR(temp1_min, 0644, show_min, set_min, 0); | |
747 | static SENSOR_DEVICE_ATTR(temp1_max, 0644, show_max, set_max, 0); | |
748 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, 0444, show_min_alarm, NULL, 0); | |
749 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, 0444, show_max_alarm, NULL, 0); | |
750 | static SENSOR_DEVICE_ATTR(temp1_crit, 0644, show_therm, set_therm, 0); | |
751 | static SENSOR_DEVICE_ATTR(temp1_crit_hyst, 0644, show_hyst, set_hyst, 0); | |
752 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, 0444, show_therm_trip, NULL, 0); | |
753 | static SENSOR_DEVICE_ATTR(update_interval, 0644, | |
754 | show_interval, set_interval, 0); | |
755 | ||
756 | static struct attribute *stts751_attrs[] = { | |
757 | &sensor_dev_attr_temp1_input.dev_attr.attr, | |
758 | &sensor_dev_attr_temp1_min.dev_attr.attr, | |
759 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
760 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
761 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
762 | &sensor_dev_attr_temp1_crit.dev_attr.attr, | |
763 | &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, | |
764 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, | |
765 | &sensor_dev_attr_update_interval.dev_attr.attr, | |
766 | NULL | |
767 | }; | |
768 | ATTRIBUTE_GROUPS(stts751); | |
769 | ||
770 | static int stts751_probe(struct i2c_client *client, | |
771 | const struct i2c_device_id *id) | |
772 | { | |
773 | struct stts751_priv *priv; | |
774 | int ret; | |
775 | bool smbus_nto; | |
776 | int rev_id; | |
777 | ||
778 | priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); | |
779 | if (!priv) | |
780 | return -ENOMEM; | |
781 | ||
782 | priv->client = client; | |
783 | priv->notify_max = true; | |
784 | priv->notify_min = true; | |
785 | i2c_set_clientdata(client, priv); | |
786 | mutex_init(&priv->access_lock); | |
787 | ||
788 | if (device_property_present(&client->dev, | |
789 | "smbus-timeout-disable")) { | |
790 | smbus_nto = device_property_read_bool(&client->dev, | |
791 | "smbus-timeout-disable"); | |
792 | ||
793 | ret = i2c_smbus_write_byte_data(client, STTS751_REG_SMBUS_TO, | |
794 | smbus_nto ? 0 : 0x80); | |
795 | if (ret) | |
796 | return ret; | |
797 | } | |
798 | ||
799 | rev_id = i2c_smbus_read_byte_data(client, STTS751_REG_REV_ID); | |
800 | if (rev_id < 0) | |
801 | return -ENODEV; | |
802 | if (rev_id != 0x1) { | |
803 | dev_dbg(&client->dev, "Chip revision 0x%x is untested\n", | |
804 | rev_id); | |
805 | } | |
806 | ||
807 | ret = stts751_read_chip_config(priv); | |
808 | if (ret) | |
809 | return ret; | |
810 | ||
811 | priv->config &= ~(STTS751_CONF_STOP | STTS751_CONF_EVENT_DIS); | |
812 | ret = i2c_smbus_write_byte_data(client, STTS751_REG_CONF, priv->config); | |
813 | if (ret) | |
814 | return ret; | |
815 | ||
816 | priv->dev = devm_hwmon_device_register_with_groups(&client->dev, | |
817 | client->name, priv, | |
818 | stts751_groups); | |
819 | return PTR_ERR_OR_ZERO(priv->dev); | |
820 | } | |
821 | ||
822 | MODULE_DEVICE_TABLE(i2c, stts751_id); | |
823 | ||
824 | static struct i2c_driver stts751_driver = { | |
825 | .class = I2C_CLASS_HWMON, | |
826 | .driver = { | |
827 | .name = DEVNAME, | |
1c1a7b75 | 828 | .of_match_table = of_match_ptr(stts751_of_match), |
7f07ec0f | 829 | }, |
830 | .probe = stts751_probe, | |
831 | .id_table = stts751_id, | |
832 | .detect = stts751_detect, | |
833 | .alert = stts751_alert, | |
834 | .address_list = normal_i2c, | |
835 | }; | |
836 | ||
837 | module_i2c_driver(stts751_driver); | |
838 | ||
839 | MODULE_AUTHOR("Andrea Merello <andrea.merello@gmail.com>"); | |
840 | MODULE_DESCRIPTION("STTS751 sensor driver"); | |
841 | MODULE_LICENSE("GPL"); |