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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 | ||
88 | struct stts751_priv { | |
89 | struct device *dev; | |
90 | struct i2c_client *client; | |
91 | struct mutex access_lock; | |
92 | u8 interval; | |
93 | int res; | |
94 | int event_max, event_min; | |
95 | int therm; | |
96 | int hyst; | |
97 | bool smbus_timeout; | |
98 | int temp; | |
99 | unsigned long last_update, last_alert_update; | |
100 | u8 config; | |
101 | bool min_alert, max_alert, therm_trip; | |
102 | bool data_valid, alert_valid; | |
103 | bool notify_max, notify_min; | |
104 | }; | |
105 | ||
106 | /* | |
107 | * These functions converts temperature from HW format to integer format and | |
108 | * vice-vers. They are (mostly) taken from lm90 driver. Unit is in mC. | |
109 | */ | |
110 | static int stts751_to_deg(s16 hw_val) | |
111 | { | |
112 | return hw_val * 125 / 32; | |
113 | } | |
114 | ||
115 | static s32 stts751_to_hw(int val) | |
116 | { | |
117 | return DIV_ROUND_CLOSEST(val, 125) * 32; | |
118 | } | |
119 | ||
120 | static int stts751_adjust_resolution(struct stts751_priv *priv) | |
121 | { | |
122 | u8 res; | |
123 | ||
124 | switch (priv->interval) { | |
125 | case 9: | |
126 | /* 10 bits */ | |
127 | res = 0; | |
128 | break; | |
129 | case 8: | |
130 | /* 11 bits */ | |
131 | res = 1; | |
132 | break; | |
133 | default: | |
134 | /* 12 bits */ | |
135 | res = 3; | |
136 | break; | |
137 | } | |
138 | ||
139 | if (priv->res == res) | |
140 | return 0; | |
141 | ||
142 | priv->config &= ~STTS751_CONF_RES_MASK; | |
143 | priv->config |= res << STTS751_CONF_RES_SHIFT; | |
144 | dev_dbg(&priv->client->dev, "setting res %d. config %x", | |
145 | res, priv->config); | |
146 | priv->res = res; | |
147 | ||
148 | return i2c_smbus_write_byte_data(priv->client, | |
149 | STTS751_REG_CONF, priv->config); | |
150 | } | |
151 | ||
152 | static int stts751_update_temp(struct stts751_priv *priv) | |
153 | { | |
154 | s32 integer1, integer2, frac; | |
155 | ||
156 | /* | |
157 | * There is a trick here, like in the lm90 driver. We have to read two | |
158 | * registers to get the sensor temperature, but we have to beware a | |
159 | * conversion could occur between the readings. We could use the | |
160 | * one-shot conversion register, but we don't want to do this (disables | |
161 | * hardware monitoring). So the solution used here is to read the high | |
162 | * byte once, then the low byte, then the high byte again. If the new | |
163 | * high byte matches the old one, then we have a valid reading. Else we | |
164 | * have to read the low byte again, and now we believe we have a correct | |
165 | * reading. | |
166 | */ | |
167 | integer1 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); | |
168 | if (integer1 < 0) { | |
169 | dev_dbg(&priv->client->dev, | |
170 | "I2C read failed (temp H). ret: %x\n", integer1); | |
171 | return integer1; | |
172 | } | |
173 | ||
174 | frac = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_L); | |
175 | if (frac < 0) { | |
176 | dev_dbg(&priv->client->dev, | |
177 | "I2C read failed (temp L). ret: %x\n", frac); | |
178 | return frac; | |
179 | } | |
180 | ||
181 | integer2 = i2c_smbus_read_byte_data(priv->client, STTS751_REG_TEMP_H); | |
182 | if (integer2 < 0) { | |
183 | dev_dbg(&priv->client->dev, | |
184 | "I2C 2nd read failed (temp H). ret: %x\n", integer2); | |
185 | return integer2; | |
186 | } | |
187 | ||
188 | if (integer1 != integer2) { | |
189 | frac = i2c_smbus_read_byte_data(priv->client, | |
190 | STTS751_REG_TEMP_L); | |
191 | if (frac < 0) { | |
192 | dev_dbg(&priv->client->dev, | |
193 | "I2C 2nd read failed (temp L). ret: %x\n", | |
194 | frac); | |
195 | return frac; | |
196 | } | |
197 | } | |
198 | ||
199 | priv->temp = stts751_to_deg((integer1 << 8) | frac); | |
200 | return 0; | |
201 | } | |
202 | ||
203 | static int stts751_set_temp_reg16(struct stts751_priv *priv, int temp, | |
204 | u8 hreg, u8 lreg) | |
205 | { | |
206 | s32 hwval; | |
207 | int ret; | |
208 | ||
209 | hwval = stts751_to_hw(temp); | |
210 | ||
211 | ret = i2c_smbus_write_byte_data(priv->client, hreg, hwval >> 8); | |
212 | if (ret) | |
213 | return ret; | |
214 | ||
215 | return i2c_smbus_write_byte_data(priv->client, lreg, hwval & 0xff); | |
216 | } | |
217 | ||
218 | static int stts751_set_temp_reg8(struct stts751_priv *priv, int temp, u8 reg) | |
219 | { | |
220 | s32 hwval; | |
221 | ||
222 | hwval = stts751_to_hw(temp); | |
223 | return i2c_smbus_write_byte_data(priv->client, reg, hwval >> 8); | |
224 | } | |
225 | ||
226 | static int stts751_read_reg16(struct stts751_priv *priv, int *temp, | |
227 | u8 hreg, u8 lreg) | |
228 | { | |
229 | int integer, frac; | |
230 | ||
231 | integer = i2c_smbus_read_byte_data(priv->client, hreg); | |
232 | if (integer < 0) | |
233 | return integer; | |
234 | ||
235 | frac = i2c_smbus_read_byte_data(priv->client, lreg); | |
236 | if (frac < 0) | |
237 | return frac; | |
238 | ||
239 | *temp = stts751_to_deg((integer << 8) | frac); | |
240 | ||
241 | return 0; | |
242 | } | |
243 | ||
244 | static int stts751_read_reg8(struct stts751_priv *priv, int *temp, u8 reg) | |
245 | { | |
246 | int integer; | |
247 | ||
248 | integer = i2c_smbus_read_byte_data(priv->client, reg); | |
249 | if (integer < 0) | |
250 | return integer; | |
251 | ||
252 | *temp = stts751_to_deg(integer << 8); | |
253 | ||
254 | return 0; | |
255 | } | |
256 | ||
257 | /* | |
258 | * Update alert flags without waiting for cache to expire. We detects alerts | |
259 | * immediately for the sake of the alert handler; we still need to deal with | |
260 | * caching to workaround the fact that alarm flags int the status register, | |
261 | * despite what the datasheet claims, gets always cleared on read. | |
262 | */ | |
263 | static int stts751_update_alert(struct stts751_priv *priv) | |
264 | { | |
265 | int ret; | |
266 | bool conv_done; | |
267 | int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); | |
268 | ||
269 | /* | |
270 | * Add another 10% because if we run faster than the HW conversion | |
271 | * rate we will end up in reporting incorrectly alarms. | |
272 | */ | |
273 | cache_time += cache_time / 10; | |
274 | ||
275 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_STATUS); | |
276 | if (ret < 0) | |
277 | return ret; | |
278 | ||
279 | dev_dbg(&priv->client->dev, "status reg %x\n", ret); | |
280 | conv_done = ret & (STTS751_STATUS_TRIPH | STTS751_STATUS_TRIPL); | |
281 | /* | |
282 | * Reset the cache if the cache time expired, or if we are sure | |
283 | * we have valid data from a device conversion, or if we know | |
284 | * our cache has been never written. | |
285 | * | |
286 | * Note that when the cache has been never written the point is | |
287 | * to correctly initialize the timestamp, rather than clearing | |
288 | * the cache values. | |
289 | * | |
290 | * Note that updating the cache timestamp when we get an alarm flag | |
291 | * is required, otherwise we could incorrectly report alarms to be zero. | |
292 | */ | |
293 | if (time_after(jiffies, priv->last_alert_update + cache_time) || | |
294 | conv_done || !priv->alert_valid) { | |
295 | priv->max_alert = false; | |
296 | priv->min_alert = false; | |
297 | priv->alert_valid = true; | |
298 | priv->last_alert_update = jiffies; | |
299 | dev_dbg(&priv->client->dev, "invalidating alert cache\n"); | |
300 | } | |
301 | ||
302 | priv->max_alert |= !!(ret & STTS751_STATUS_TRIPH); | |
303 | priv->min_alert |= !!(ret & STTS751_STATUS_TRIPL); | |
304 | priv->therm_trip = !!(ret & STTS751_STATUS_TRIPT); | |
305 | ||
306 | dev_dbg(&priv->client->dev, "max_alert: %d, min_alert: %d, therm_trip: %d\n", | |
307 | priv->max_alert, priv->min_alert, priv->therm_trip); | |
308 | ||
309 | return 0; | |
310 | } | |
311 | ||
312 | static void stts751_alert(struct i2c_client *client, | |
313 | enum i2c_alert_protocol type, unsigned int data) | |
314 | { | |
315 | int ret; | |
316 | struct stts751_priv *priv = i2c_get_clientdata(client); | |
317 | ||
318 | if (type != I2C_PROTOCOL_SMBUS_ALERT) | |
319 | return; | |
320 | ||
321 | dev_dbg(&client->dev, "alert!"); | |
322 | ||
323 | mutex_lock(&priv->access_lock); | |
324 | ret = stts751_update_alert(priv); | |
325 | if (ret < 0) { | |
326 | /* default to worst case */ | |
327 | priv->max_alert = true; | |
328 | priv->min_alert = true; | |
329 | ||
330 | dev_warn(priv->dev, | |
331 | "Alert received, but can't communicate to the device. Triggering all alarms!"); | |
332 | } | |
333 | ||
334 | if (priv->max_alert) { | |
335 | if (priv->notify_max) | |
336 | dev_notice(priv->dev, "got alert for HIGH temperature"); | |
337 | priv->notify_max = false; | |
338 | ||
339 | /* unblock alert poll */ | |
340 | sysfs_notify(&priv->dev->kobj, NULL, "temp1_max_alarm"); | |
341 | } | |
342 | ||
343 | if (priv->min_alert) { | |
344 | if (priv->notify_min) | |
345 | dev_notice(priv->dev, "got alert for LOW temperature"); | |
346 | priv->notify_min = false; | |
347 | ||
348 | /* unblock alert poll */ | |
349 | sysfs_notify(&priv->dev->kobj, NULL, "temp1_min_alarm"); | |
350 | } | |
351 | ||
352 | if (priv->min_alert || priv->max_alert) | |
353 | kobject_uevent(&priv->dev->kobj, KOBJ_CHANGE); | |
354 | ||
355 | mutex_unlock(&priv->access_lock); | |
356 | } | |
357 | ||
358 | static int stts751_update(struct stts751_priv *priv) | |
359 | { | |
360 | int ret; | |
361 | int cache_time = msecs_to_jiffies(stts751_intervals[priv->interval]); | |
362 | ||
363 | if (time_after(jiffies, priv->last_update + cache_time) || | |
364 | !priv->data_valid) { | |
365 | ret = stts751_update_temp(priv); | |
366 | if (ret) | |
367 | return ret; | |
368 | ||
369 | ret = stts751_update_alert(priv); | |
370 | if (ret) | |
371 | return ret; | |
372 | priv->data_valid = true; | |
373 | priv->last_update = jiffies; | |
374 | } | |
375 | ||
376 | return 0; | |
377 | } | |
378 | ||
379 | static ssize_t show_max_alarm(struct device *dev, struct device_attribute *attr, | |
380 | char *buf) | |
381 | { | |
382 | int ret; | |
383 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
384 | ||
385 | mutex_lock(&priv->access_lock); | |
386 | ret = stts751_update(priv); | |
387 | if (!ret) | |
388 | priv->notify_max = true; | |
389 | mutex_unlock(&priv->access_lock); | |
390 | if (ret < 0) | |
391 | return ret; | |
392 | ||
393 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->max_alert); | |
394 | } | |
395 | ||
396 | static ssize_t show_min_alarm(struct device *dev, struct device_attribute *attr, | |
397 | char *buf) | |
398 | { | |
399 | int ret; | |
400 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
401 | ||
402 | mutex_lock(&priv->access_lock); | |
403 | ret = stts751_update(priv); | |
404 | if (!ret) | |
405 | priv->notify_min = true; | |
406 | mutex_unlock(&priv->access_lock); | |
407 | if (ret < 0) | |
408 | return ret; | |
409 | ||
410 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->min_alert); | |
411 | } | |
412 | ||
413 | static ssize_t show_input(struct device *dev, struct device_attribute *attr, | |
414 | char *buf) | |
415 | { | |
416 | int ret; | |
417 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
418 | ||
419 | mutex_lock(&priv->access_lock); | |
420 | ret = stts751_update(priv); | |
421 | mutex_unlock(&priv->access_lock); | |
422 | if (ret < 0) | |
423 | return ret; | |
424 | ||
425 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->temp); | |
426 | } | |
427 | ||
428 | static ssize_t show_therm(struct device *dev, struct device_attribute *attr, | |
429 | char *buf) | |
430 | { | |
431 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
432 | ||
433 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->therm); | |
434 | } | |
435 | ||
436 | static ssize_t set_therm(struct device *dev, struct device_attribute *attr, | |
437 | const char *buf, size_t count) | |
438 | { | |
439 | int ret; | |
440 | long temp; | |
441 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
442 | ||
443 | if (kstrtol(buf, 10, &temp) < 0) | |
444 | return -EINVAL; | |
445 | ||
446 | /* HW works in range -64C to +127.937C */ | |
447 | temp = clamp_val(temp, -64000, 127937); | |
448 | mutex_lock(&priv->access_lock); | |
449 | ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_TLIM); | |
450 | if (ret) | |
451 | goto exit; | |
452 | ||
453 | dev_dbg(&priv->client->dev, "setting therm %ld", temp); | |
454 | ||
455 | /* | |
456 | * hysteresis reg is relative to therm, so the HW does not need to be | |
457 | * adjusted, we need to update our local copy only. | |
458 | */ | |
459 | priv->hyst = temp - (priv->therm - priv->hyst); | |
460 | priv->therm = temp; | |
461 | ||
462 | exit: | |
463 | mutex_unlock(&priv->access_lock); | |
464 | if (ret) | |
465 | return ret; | |
466 | ||
467 | return count; | |
468 | } | |
469 | ||
470 | static ssize_t show_hyst(struct device *dev, struct device_attribute *attr, | |
471 | char *buf) | |
472 | { | |
473 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
474 | ||
475 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->hyst); | |
476 | } | |
477 | ||
478 | static ssize_t set_hyst(struct device *dev, struct device_attribute *attr, | |
479 | const char *buf, size_t count) | |
480 | { | |
481 | int ret; | |
482 | long temp; | |
483 | ||
484 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
485 | ||
486 | if (kstrtol(buf, 10, &temp) < 0) | |
487 | return -EINVAL; | |
488 | ||
489 | mutex_lock(&priv->access_lock); | |
490 | /* HW works in range -64C to +127.937C */ | |
491 | temp = clamp_val(temp, -64000, priv->therm); | |
492 | priv->hyst = temp; | |
493 | dev_dbg(&priv->client->dev, "setting hyst %ld", temp); | |
494 | temp = priv->therm - temp; | |
495 | ret = stts751_set_temp_reg8(priv, temp, STTS751_REG_HYST); | |
496 | mutex_unlock(&priv->access_lock); | |
497 | if (ret) | |
498 | return ret; | |
499 | ||
500 | return count; | |
501 | } | |
502 | ||
503 | static ssize_t show_therm_trip(struct device *dev, | |
504 | struct device_attribute *attr, char *buf) | |
505 | { | |
506 | int ret; | |
507 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
508 | ||
509 | mutex_lock(&priv->access_lock); | |
510 | ret = stts751_update(priv); | |
511 | mutex_unlock(&priv->access_lock); | |
512 | if (ret < 0) | |
513 | return ret; | |
514 | ||
515 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->therm_trip); | |
516 | } | |
517 | ||
518 | static ssize_t show_max(struct device *dev, struct device_attribute *attr, | |
519 | char *buf) | |
520 | { | |
521 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
522 | ||
523 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->event_max); | |
524 | } | |
525 | ||
526 | static ssize_t set_max(struct device *dev, struct device_attribute *attr, | |
527 | const char *buf, size_t count) | |
528 | { | |
529 | int ret; | |
530 | long temp; | |
531 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
532 | ||
533 | if (kstrtol(buf, 10, &temp) < 0) | |
534 | return -EINVAL; | |
535 | ||
536 | mutex_lock(&priv->access_lock); | |
537 | /* HW works in range -64C to +127.937C */ | |
538 | temp = clamp_val(temp, priv->event_min, 127937); | |
539 | ret = stts751_set_temp_reg16(priv, temp, | |
540 | STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); | |
541 | if (ret) | |
542 | goto exit; | |
543 | ||
544 | dev_dbg(&priv->client->dev, "setting event max %ld", temp); | |
545 | priv->event_max = temp; | |
546 | ret = count; | |
547 | exit: | |
548 | mutex_unlock(&priv->access_lock); | |
549 | return ret; | |
550 | } | |
551 | ||
552 | static ssize_t show_min(struct device *dev, struct device_attribute *attr, | |
553 | char *buf) | |
554 | { | |
555 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
556 | ||
557 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", priv->event_min); | |
558 | } | |
559 | ||
560 | static ssize_t set_min(struct device *dev, struct device_attribute *attr, | |
561 | const char *buf, size_t count) | |
562 | { | |
563 | int ret; | |
564 | long temp; | |
565 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
566 | ||
567 | if (kstrtol(buf, 10, &temp) < 0) | |
568 | return -EINVAL; | |
569 | ||
570 | mutex_lock(&priv->access_lock); | |
571 | /* HW works in range -64C to +127.937C */ | |
572 | temp = clamp_val(temp, -64000, priv->event_max); | |
573 | ret = stts751_set_temp_reg16(priv, temp, | |
574 | STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); | |
575 | if (ret) | |
576 | goto exit; | |
577 | ||
578 | dev_dbg(&priv->client->dev, "setting event min %ld", temp); | |
579 | priv->event_min = temp; | |
580 | ret = count; | |
581 | exit: | |
582 | mutex_unlock(&priv->access_lock); | |
583 | return ret; | |
584 | } | |
585 | ||
586 | static ssize_t show_interval(struct device *dev, struct device_attribute *attr, | |
587 | char *buf) | |
588 | { | |
589 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
590 | ||
591 | return snprintf(buf, PAGE_SIZE - 1, "%d\n", | |
592 | stts751_intervals[priv->interval]); | |
593 | } | |
594 | ||
595 | static ssize_t set_interval(struct device *dev, struct device_attribute *attr, | |
596 | const char *buf, size_t count) | |
597 | { | |
598 | unsigned long val; | |
599 | int idx; | |
600 | int ret = count; | |
601 | struct stts751_priv *priv = dev_get_drvdata(dev); | |
602 | ||
603 | if (kstrtoul(buf, 10, &val) < 0) | |
604 | return -EINVAL; | |
605 | ||
606 | idx = find_closest_descending(val, stts751_intervals, | |
607 | ARRAY_SIZE(stts751_intervals)); | |
608 | ||
609 | dev_dbg(&priv->client->dev, "setting interval. req:%lu, idx: %d, val: %d", | |
610 | val, idx, stts751_intervals[idx]); | |
611 | ||
612 | mutex_lock(&priv->access_lock); | |
613 | if (priv->interval == idx) | |
614 | goto exit; | |
615 | ||
616 | /* | |
617 | * In early development stages I've become suspicious about the chip | |
618 | * starting to misbehave if I ever set, even briefly, an invalid | |
619 | * configuration. While I'm not sure this is really needed, be | |
620 | * conservative and set rate/resolution in such an order that avoids | |
621 | * passing through an invalid configuration. | |
622 | */ | |
623 | ||
624 | /* speed up: lower the resolution, then modify convrate */ | |
625 | if (priv->interval < idx) { | |
626 | dev_dbg(&priv->client->dev, "lower resolution, then modify convrate"); | |
627 | priv->interval = idx; | |
628 | ret = stts751_adjust_resolution(priv); | |
629 | if (ret) | |
630 | goto exit; | |
631 | } | |
632 | ||
633 | ret = i2c_smbus_write_byte_data(priv->client, STTS751_REG_RATE, idx); | |
634 | if (ret) | |
635 | goto exit; | |
636 | /* slow down: modify convrate, then raise resolution */ | |
637 | if (priv->interval != idx) { | |
638 | dev_dbg(&priv->client->dev, "modify convrate, then raise resolution"); | |
639 | priv->interval = idx; | |
640 | ret = stts751_adjust_resolution(priv); | |
641 | if (ret) | |
642 | goto exit; | |
643 | } | |
644 | ret = count; | |
645 | exit: | |
646 | mutex_unlock(&priv->access_lock); | |
647 | ||
648 | return ret; | |
649 | } | |
650 | ||
651 | static int stts751_detect(struct i2c_client *new_client, | |
652 | struct i2c_board_info *info) | |
653 | { | |
654 | struct i2c_adapter *adapter = new_client->adapter; | |
655 | const char *name; | |
656 | int tmp; | |
657 | ||
658 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA)) | |
659 | return -ENODEV; | |
660 | ||
661 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_MAN_ID); | |
662 | if (tmp != ST_MAN_ID) | |
663 | return -ENODEV; | |
664 | ||
665 | /* lower temperaure registers always have bits 0-3 set to zero */ | |
666 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_TEMP_L); | |
667 | if (tmp & 0xf) | |
668 | return -ENODEV; | |
669 | ||
670 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_HLIM_L); | |
671 | if (tmp & 0xf) | |
672 | return -ENODEV; | |
673 | ||
674 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_LLIM_L); | |
675 | if (tmp & 0xf) | |
676 | return -ENODEV; | |
677 | ||
678 | /* smbus timeout register always have bits 0-7 set to zero */ | |
679 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_SMBUS_TO); | |
680 | if (tmp & 0x7f) | |
681 | return -ENODEV; | |
682 | ||
683 | tmp = i2c_smbus_read_byte_data(new_client, STTS751_REG_PROD_ID); | |
684 | ||
685 | switch (tmp) { | |
686 | case STTS751_0_PROD_ID: | |
687 | name = "STTS751-0"; | |
688 | break; | |
689 | case STTS751_1_PROD_ID: | |
690 | name = "STTS751-1"; | |
691 | break; | |
692 | default: | |
693 | return -ENODEV; | |
694 | } | |
695 | dev_dbg(&new_client->dev, "Chip %s detected", name); | |
696 | ||
697 | strlcpy(info->type, stts751_id[0].name, I2C_NAME_SIZE); | |
698 | return 0; | |
699 | } | |
700 | ||
701 | static int stts751_read_chip_config(struct stts751_priv *priv) | |
702 | { | |
703 | int ret; | |
704 | int tmp; | |
705 | ||
706 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_CONF); | |
707 | if (ret < 0) | |
708 | return ret; | |
709 | priv->config = ret; | |
710 | priv->res = (ret & STTS751_CONF_RES_MASK) >> STTS751_CONF_RES_SHIFT; | |
711 | ||
712 | ret = i2c_smbus_read_byte_data(priv->client, STTS751_REG_RATE); | |
713 | if (ret < 0) | |
714 | return ret; | |
715 | priv->interval = ret; | |
716 | ||
717 | ret = stts751_read_reg16(priv, &priv->event_max, | |
718 | STTS751_REG_HLIM_H, STTS751_REG_HLIM_L); | |
719 | if (ret) | |
720 | return ret; | |
721 | ||
722 | ret = stts751_read_reg16(priv, &priv->event_min, | |
723 | STTS751_REG_LLIM_H, STTS751_REG_LLIM_L); | |
724 | if (ret) | |
725 | return ret; | |
726 | ||
727 | ret = stts751_read_reg8(priv, &priv->therm, STTS751_REG_TLIM); | |
728 | if (ret) | |
729 | return ret; | |
730 | ||
731 | ret = stts751_read_reg8(priv, &tmp, STTS751_REG_HYST); | |
732 | if (ret) | |
733 | return ret; | |
734 | priv->hyst = priv->therm - tmp; | |
735 | ||
736 | return 0; | |
737 | } | |
738 | ||
739 | static SENSOR_DEVICE_ATTR(temp1_input, 0444, show_input, NULL, 0); | |
740 | static SENSOR_DEVICE_ATTR(temp1_min, 0644, show_min, set_min, 0); | |
741 | static SENSOR_DEVICE_ATTR(temp1_max, 0644, show_max, set_max, 0); | |
742 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, 0444, show_min_alarm, NULL, 0); | |
743 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, 0444, show_max_alarm, NULL, 0); | |
744 | static SENSOR_DEVICE_ATTR(temp1_crit, 0644, show_therm, set_therm, 0); | |
745 | static SENSOR_DEVICE_ATTR(temp1_crit_hyst, 0644, show_hyst, set_hyst, 0); | |
746 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, 0444, show_therm_trip, NULL, 0); | |
747 | static SENSOR_DEVICE_ATTR(update_interval, 0644, | |
748 | show_interval, set_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 | ||
764 | static int stts751_probe(struct i2c_client *client, | |
765 | const struct i2c_device_id *id) | |
766 | { | |
767 | struct stts751_priv *priv; | |
768 | int ret; | |
769 | bool smbus_nto; | |
770 | int rev_id; | |
771 | ||
772 | priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); | |
773 | if (!priv) | |
774 | return -ENOMEM; | |
775 | ||
776 | priv->client = client; | |
777 | priv->notify_max = true; | |
778 | priv->notify_min = true; | |
779 | i2c_set_clientdata(client, priv); | |
780 | mutex_init(&priv->access_lock); | |
781 | ||
782 | if (device_property_present(&client->dev, | |
783 | "smbus-timeout-disable")) { | |
784 | smbus_nto = device_property_read_bool(&client->dev, | |
785 | "smbus-timeout-disable"); | |
786 | ||
787 | ret = i2c_smbus_write_byte_data(client, STTS751_REG_SMBUS_TO, | |
788 | smbus_nto ? 0 : 0x80); | |
789 | if (ret) | |
790 | return ret; | |
791 | } | |
792 | ||
793 | rev_id = i2c_smbus_read_byte_data(client, STTS751_REG_REV_ID); | |
794 | if (rev_id < 0) | |
795 | return -ENODEV; | |
796 | if (rev_id != 0x1) { | |
797 | dev_dbg(&client->dev, "Chip revision 0x%x is untested\n", | |
798 | rev_id); | |
799 | } | |
800 | ||
801 | ret = stts751_read_chip_config(priv); | |
802 | if (ret) | |
803 | return ret; | |
804 | ||
805 | priv->config &= ~(STTS751_CONF_STOP | STTS751_CONF_EVENT_DIS); | |
806 | ret = i2c_smbus_write_byte_data(client, STTS751_REG_CONF, priv->config); | |
807 | if (ret) | |
808 | return ret; | |
809 | ||
810 | priv->dev = devm_hwmon_device_register_with_groups(&client->dev, | |
811 | client->name, priv, | |
812 | stts751_groups); | |
813 | return PTR_ERR_OR_ZERO(priv->dev); | |
814 | } | |
815 | ||
816 | MODULE_DEVICE_TABLE(i2c, stts751_id); | |
817 | ||
818 | static struct i2c_driver stts751_driver = { | |
819 | .class = I2C_CLASS_HWMON, | |
820 | .driver = { | |
821 | .name = DEVNAME, | |
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"); |