1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com>
4 *
5 * The LM95245 is a sensor chip made by TI / National Semiconductor.
6 * It reports up to two temperatures (its own plus an external one).
7 *
8 * This driver is based on lm95241.c
9 */
10
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/hwmon.h>
14 #include <linux/i2c.h>
15 #include <linux/module.h>
16 #include <linux/mutex.h>
17 #include <linux/regmap.h>
18 #include <linux/slab.h>
19
20 static const unsigned short normal_i2c[] = {
21 0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END };
22
23 /* LM95245 registers */
24 /* general registers */
25 #define LM95245_REG_RW_CONFIG1 0x03
26 #define LM95245_REG_RW_CONVERS_RATE 0x04
27 #define LM95245_REG_W_ONE_SHOT 0x0F
28
29 /* diode configuration */
30 #define LM95245_REG_RW_CONFIG2 0xBF
31 #define LM95245_REG_RW_REMOTE_OFFH 0x11
32 #define LM95245_REG_RW_REMOTE_OFFL 0x12
33
34 /* status registers */
35 #define LM95245_REG_R_STATUS1 0x02
36 #define LM95245_REG_R_STATUS2 0x33
37
38 /* limit registers */
39 #define LM95245_REG_RW_REMOTE_OS_LIMIT 0x07
40 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT 0x20
41 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT 0x19
42 #define LM95245_REG_RW_COMMON_HYSTERESIS 0x21
43
44 /* temperature signed */
45 #define LM95245_REG_R_LOCAL_TEMPH_S 0x00
46 #define LM95245_REG_R_LOCAL_TEMPL_S 0x30
47 #define LM95245_REG_R_REMOTE_TEMPH_S 0x01
48 #define LM95245_REG_R_REMOTE_TEMPL_S 0x10
49 /* temperature unsigned */
50 #define LM95245_REG_R_REMOTE_TEMPH_U 0x31
51 #define LM95245_REG_R_REMOTE_TEMPL_U 0x32
52
53 /* id registers */
54 #define LM95245_REG_R_MAN_ID 0xFE
55 #define LM95245_REG_R_CHIP_ID 0xFF
56
57 /* LM95245 specific bitfields */
58 #define CFG_STOP 0x40
59 #define CFG_REMOTE_TCRIT_MASK 0x10
60 #define CFG_REMOTE_OS_MASK 0x08
61 #define CFG_LOCAL_TCRIT_MASK 0x04
62 #define CFG_LOCAL_OS_MASK 0x02
63
64 #define CFG2_OS_A0 0x40
65 #define CFG2_DIODE_FAULT_OS 0x20
66 #define CFG2_DIODE_FAULT_TCRIT 0x10
67 #define CFG2_REMOTE_TT 0x08
68 #define CFG2_REMOTE_FILTER_DIS 0x00
69 #define CFG2_REMOTE_FILTER_EN 0x06
70
71 /* conversation rate in ms */
72 #define RATE_CR0063 0x00
73 #define RATE_CR0364 0x01
74 #define RATE_CR1000 0x02
75 #define RATE_CR2500 0x03
76
77 #define STATUS1_ROS 0x10
78 #define STATUS1_DIODE_FAULT 0x04
79 #define STATUS1_RTCRIT 0x02
80 #define STATUS1_LOC 0x01
81
82 #define MANUFACTURER_ID 0x01
83 #define LM95235_REVISION 0xB1
84 #define LM95245_REVISION 0xB3
85
86 /* Client data (each client gets its own) */
87 struct lm95245_data {
88 struct regmap *regmap;
89 struct mutex update_lock;
90 int interval; /* in msecs */
91 };
92
93 /* Conversions */
temp_from_reg_unsigned(u8 val_h,u8 val_l)94 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
95 {
96 return val_h * 1000 + val_l * 1000 / 256;
97 }
98
temp_from_reg_signed(u8 val_h,u8 val_l)99 static int temp_from_reg_signed(u8 val_h, u8 val_l)
100 {
101 if (val_h & 0x80)
102 return (val_h - 0x100) * 1000;
103 return temp_from_reg_unsigned(val_h, val_l);
104 }
105
lm95245_read_conversion_rate(struct lm95245_data * data)106 static int lm95245_read_conversion_rate(struct lm95245_data *data)
107 {
108 unsigned int rate;
109 int ret;
110
111 ret = regmap_read(data->regmap, LM95245_REG_RW_CONVERS_RATE, &rate);
112 if (ret < 0)
113 return ret;
114
115 switch (rate) {
116 case RATE_CR0063:
117 data->interval = 63;
118 break;
119 case RATE_CR0364:
120 data->interval = 364;
121 break;
122 case RATE_CR1000:
123 data->interval = 1000;
124 break;
125 case RATE_CR2500:
126 default:
127 data->interval = 2500;
128 break;
129 }
130 return 0;
131 }
132
lm95245_set_conversion_rate(struct lm95245_data * data,long interval)133 static int lm95245_set_conversion_rate(struct lm95245_data *data, long interval)
134 {
135 int ret, rate;
136
137 if (interval <= 63) {
138 interval = 63;
139 rate = RATE_CR0063;
140 } else if (interval <= 364) {
141 interval = 364;
142 rate = RATE_CR0364;
143 } else if (interval <= 1000) {
144 interval = 1000;
145 rate = RATE_CR1000;
146 } else {
147 interval = 2500;
148 rate = RATE_CR2500;
149 }
150
151 ret = regmap_write(data->regmap, LM95245_REG_RW_CONVERS_RATE, rate);
152 if (ret < 0)
153 return ret;
154
155 data->interval = interval;
156 return 0;
157 }
158
lm95245_read_temp(struct device * dev,u32 attr,int channel,long * val)159 static int lm95245_read_temp(struct device *dev, u32 attr, int channel,
160 long *val)
161 {
162 struct lm95245_data *data = dev_get_drvdata(dev);
163 struct regmap *regmap = data->regmap;
164 unsigned int regs[2];
165 unsigned int regval;
166 u8 regvals[2];
167 int ret;
168
169 switch (attr) {
170 case hwmon_temp_input:
171 regs[0] = channel ? LM95245_REG_R_REMOTE_TEMPL_S :
172 LM95245_REG_R_LOCAL_TEMPL_S;
173 regs[1] = channel ? LM95245_REG_R_REMOTE_TEMPH_S :
174 LM95245_REG_R_LOCAL_TEMPH_S;
175 ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
176 if (ret < 0)
177 return ret;
178 /*
179 * Local temp is always signed.
180 * Remote temp has both signed and unsigned data.
181 * Use signed calculation for remote if signed bit is set
182 * or if reported temperature is below signed limit.
183 */
184 if (!channel || (regvals[1] & 0x80) || regvals[1] < 0x7f) {
185 *val = temp_from_reg_signed(regvals[1], regvals[0]);
186 return 0;
187 }
188 ret = regmap_bulk_read(regmap, LM95245_REG_R_REMOTE_TEMPH_U, regvals, 2);
189 if (ret)
190 return ret;
191 *val = temp_from_reg_unsigned(regvals[0], regvals[1]);
192 return 0;
193 case hwmon_temp_max:
194 ret = regmap_read(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT,
195 ®val);
196 if (ret < 0)
197 return ret;
198 *val = regval * 1000;
199 return 0;
200 case hwmon_temp_crit:
201 regs[0] = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT :
202 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT;
203 ret = regmap_read(regmap, regs[0], ®val);
204 if (ret < 0)
205 return ret;
206 *val = regval * 1000;
207 return 0;
208 case hwmon_temp_max_hyst:
209 regs[0] = LM95245_REG_RW_REMOTE_OS_LIMIT;
210 regs[1] = LM95245_REG_RW_COMMON_HYSTERESIS;
211 ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
212 if (ret < 0)
213 return ret;
214 *val = (regvals[0] - regvals[1]) * 1000;
215 return 0;
216 case hwmon_temp_crit_hyst:
217 regs[0] = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT :
218 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT;
219 regs[1] = LM95245_REG_RW_COMMON_HYSTERESIS;
220
221 ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
222 if (ret < 0)
223 return ret;
224 *val = (regvals[0] - regvals[1]) * 1000;
225 return 0;
226 case hwmon_temp_type:
227 ret = regmap_read(regmap, LM95245_REG_RW_CONFIG2, ®val);
228 if (ret < 0)
229 return ret;
230 *val = (regval & CFG2_REMOTE_TT) ? 1 : 2;
231 return 0;
232 case hwmon_temp_offset:
233 ret = regmap_bulk_read(regmap, LM95245_REG_RW_REMOTE_OFFH, regvals, 2);
234 if (ret < 0)
235 return ret;
236 *val = temp_from_reg_signed(regvals[0], regvals[1]);
237 return 0;
238 case hwmon_temp_max_alarm:
239 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®val);
240 if (ret < 0)
241 return ret;
242 *val = !!(regval & STATUS1_ROS);
243 return 0;
244 case hwmon_temp_crit_alarm:
245 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®val);
246 if (ret < 0)
247 return ret;
248 *val = !!(regval & (channel ? STATUS1_RTCRIT : STATUS1_LOC));
249 return 0;
250 case hwmon_temp_fault:
251 ret = regmap_read(regmap, LM95245_REG_R_STATUS1, ®val);
252 if (ret < 0)
253 return ret;
254 *val = !!(regval & STATUS1_DIODE_FAULT);
255 return 0;
256 default:
257 return -EOPNOTSUPP;
258 }
259 }
260
lm95245_write_temp(struct device * dev,u32 attr,int channel,long val)261 static int lm95245_write_temp(struct device *dev, u32 attr, int channel,
262 long val)
263 {
264 struct lm95245_data *data = dev_get_drvdata(dev);
265 struct regmap *regmap = data->regmap;
266 unsigned int regval;
267 u8 regvals[2];
268 int ret, reg;
269
270 switch (attr) {
271 case hwmon_temp_max:
272 val = clamp_val(val / 1000, 0, 255);
273 ret = regmap_write(regmap, LM95245_REG_RW_REMOTE_OS_LIMIT, val);
274 return ret;
275 case hwmon_temp_crit:
276 reg = channel ? LM95245_REG_RW_REMOTE_TCRIT_LIMIT :
277 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT;
278 val = clamp_val(val / 1000, 0, channel ? 255 : 127);
279 ret = regmap_write(regmap, reg, val);
280 return ret;
281 case hwmon_temp_crit_hyst:
282 mutex_lock(&data->update_lock);
283 ret = regmap_read(regmap, LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
284 ®val);
285 if (ret < 0) {
286 mutex_unlock(&data->update_lock);
287 return ret;
288 }
289 /* Clamp to reasonable range to prevent overflow */
290 val = clamp_val(val, -1000000, 1000000);
291 val = regval - val / 1000;
292 val = clamp_val(val, 0, 31);
293 ret = regmap_write(regmap, LM95245_REG_RW_COMMON_HYSTERESIS,
294 val);
295 mutex_unlock(&data->update_lock);
296 return ret;
297 case hwmon_temp_offset:
298 val = clamp_val(val, -128000, 127875);
299 val = val * 256 / 1000;
300 regvals[0] = val >> 8;
301 regvals[1] = val & 0xe0;
302
303 ret = regmap_bulk_write(regmap, LM95245_REG_RW_REMOTE_OFFH, regvals, 2);
304 return ret;
305 case hwmon_temp_type:
306 if (val != 1 && val != 2)
307 return -EINVAL;
308 ret = regmap_update_bits(regmap, LM95245_REG_RW_CONFIG2,
309 CFG2_REMOTE_TT,
310 val == 1 ? CFG2_REMOTE_TT : 0);
311 return ret;
312 default:
313 return -EOPNOTSUPP;
314 }
315 }
316
lm95245_read_chip(struct device * dev,u32 attr,int channel,long * val)317 static int lm95245_read_chip(struct device *dev, u32 attr, int channel,
318 long *val)
319 {
320 struct lm95245_data *data = dev_get_drvdata(dev);
321
322 switch (attr) {
323 case hwmon_chip_update_interval:
324 *val = data->interval;
325 return 0;
326 default:
327 return -EOPNOTSUPP;
328 }
329 }
330
lm95245_write_chip(struct device * dev,u32 attr,int channel,long val)331 static int lm95245_write_chip(struct device *dev, u32 attr, int channel,
332 long val)
333 {
334 struct lm95245_data *data = dev_get_drvdata(dev);
335 int ret;
336
337 switch (attr) {
338 case hwmon_chip_update_interval:
339 mutex_lock(&data->update_lock);
340 ret = lm95245_set_conversion_rate(data, val);
341 mutex_unlock(&data->update_lock);
342 return ret;
343 default:
344 return -EOPNOTSUPP;
345 }
346 }
347
lm95245_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)348 static int lm95245_read(struct device *dev, enum hwmon_sensor_types type,
349 u32 attr, int channel, long *val)
350 {
351 switch (type) {
352 case hwmon_chip:
353 return lm95245_read_chip(dev, attr, channel, val);
354 case hwmon_temp:
355 return lm95245_read_temp(dev, attr, channel, val);
356 default:
357 return -EOPNOTSUPP;
358 }
359 }
360
lm95245_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)361 static int lm95245_write(struct device *dev, enum hwmon_sensor_types type,
362 u32 attr, int channel, long val)
363 {
364 switch (type) {
365 case hwmon_chip:
366 return lm95245_write_chip(dev, attr, channel, val);
367 case hwmon_temp:
368 return lm95245_write_temp(dev, attr, channel, val);
369 default:
370 return -EOPNOTSUPP;
371 }
372 }
373
lm95245_temp_is_visible(const void * data,u32 attr,int channel)374 static umode_t lm95245_temp_is_visible(const void *data, u32 attr, int channel)
375 {
376 switch (attr) {
377 case hwmon_temp_input:
378 case hwmon_temp_max_alarm:
379 case hwmon_temp_max_hyst:
380 case hwmon_temp_crit_alarm:
381 case hwmon_temp_fault:
382 return 0444;
383 case hwmon_temp_type:
384 case hwmon_temp_max:
385 case hwmon_temp_crit:
386 case hwmon_temp_offset:
387 return 0644;
388 case hwmon_temp_crit_hyst:
389 return (channel == 0) ? 0644 : 0444;
390 default:
391 return 0;
392 }
393 }
394
lm95245_is_visible(const void * data,enum hwmon_sensor_types type,u32 attr,int channel)395 static umode_t lm95245_is_visible(const void *data,
396 enum hwmon_sensor_types type,
397 u32 attr, int channel)
398 {
399 switch (type) {
400 case hwmon_chip:
401 switch (attr) {
402 case hwmon_chip_update_interval:
403 return 0644;
404 default:
405 return 0;
406 }
407 case hwmon_temp:
408 return lm95245_temp_is_visible(data, attr, channel);
409 default:
410 return 0;
411 }
412 }
413
414 /* Return 0 if detection is successful, -ENODEV otherwise */
lm95245_detect(struct i2c_client * new_client,struct i2c_board_info * info)415 static int lm95245_detect(struct i2c_client *new_client,
416 struct i2c_board_info *info)
417 {
418 struct i2c_adapter *adapter = new_client->adapter;
419 int address = new_client->addr;
420 const char *name;
421 int rev, id;
422
423 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
424 return -ENODEV;
425
426 id = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID);
427 if (id != MANUFACTURER_ID)
428 return -ENODEV;
429
430 rev = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID);
431 switch (rev) {
432 case LM95235_REVISION:
433 if (address != 0x18 && address != 0x29 && address != 0x4c)
434 return -ENODEV;
435 name = "lm95235";
436 break;
437 case LM95245_REVISION:
438 name = "lm95245";
439 break;
440 default:
441 return -ENODEV;
442 }
443
444 strscpy(info->type, name, I2C_NAME_SIZE);
445 return 0;
446 }
447
lm95245_init_client(struct lm95245_data * data)448 static int lm95245_init_client(struct lm95245_data *data)
449 {
450 int ret;
451
452 ret = lm95245_read_conversion_rate(data);
453 if (ret < 0)
454 return ret;
455
456 return regmap_update_bits(data->regmap, LM95245_REG_RW_CONFIG1,
457 CFG_STOP, 0);
458 }
459
lm95245_is_writeable_reg(struct device * dev,unsigned int reg)460 static bool lm95245_is_writeable_reg(struct device *dev, unsigned int reg)
461 {
462 switch (reg) {
463 case LM95245_REG_RW_CONFIG1:
464 case LM95245_REG_RW_CONVERS_RATE:
465 case LM95245_REG_W_ONE_SHOT:
466 case LM95245_REG_RW_CONFIG2:
467 case LM95245_REG_RW_REMOTE_OFFH:
468 case LM95245_REG_RW_REMOTE_OFFL:
469 case LM95245_REG_RW_REMOTE_OS_LIMIT:
470 case LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT:
471 case LM95245_REG_RW_REMOTE_TCRIT_LIMIT:
472 case LM95245_REG_RW_COMMON_HYSTERESIS:
473 return true;
474 default:
475 return false;
476 }
477 }
478
lm95245_is_volatile_reg(struct device * dev,unsigned int reg)479 static bool lm95245_is_volatile_reg(struct device *dev, unsigned int reg)
480 {
481 switch (reg) {
482 case LM95245_REG_R_STATUS1:
483 case LM95245_REG_R_STATUS2:
484 case LM95245_REG_R_LOCAL_TEMPH_S:
485 case LM95245_REG_R_LOCAL_TEMPL_S:
486 case LM95245_REG_R_REMOTE_TEMPH_S:
487 case LM95245_REG_R_REMOTE_TEMPL_S:
488 case LM95245_REG_R_REMOTE_TEMPH_U:
489 case LM95245_REG_R_REMOTE_TEMPL_U:
490 return true;
491 default:
492 return false;
493 }
494 }
495
496 static const struct regmap_config lm95245_regmap_config = {
497 .reg_bits = 8,
498 .val_bits = 8,
499 .writeable_reg = lm95245_is_writeable_reg,
500 .volatile_reg = lm95245_is_volatile_reg,
501 .cache_type = REGCACHE_MAPLE,
502 .use_single_read = true,
503 .use_single_write = true,
504 };
505
506 static const struct hwmon_channel_info * const lm95245_info[] = {
507 HWMON_CHANNEL_INFO(chip,
508 HWMON_C_UPDATE_INTERVAL),
509 HWMON_CHANNEL_INFO(temp,
510 HWMON_T_INPUT | HWMON_T_CRIT | HWMON_T_CRIT_HYST |
511 HWMON_T_CRIT_ALARM,
512 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST |
513 HWMON_T_CRIT | HWMON_T_CRIT_HYST | HWMON_T_FAULT |
514 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM |
515 HWMON_T_TYPE | HWMON_T_OFFSET),
516 NULL
517 };
518
519 static const struct hwmon_ops lm95245_hwmon_ops = {
520 .is_visible = lm95245_is_visible,
521 .read = lm95245_read,
522 .write = lm95245_write,
523 };
524
525 static const struct hwmon_chip_info lm95245_chip_info = {
526 .ops = &lm95245_hwmon_ops,
527 .info = lm95245_info,
528 };
529
lm95245_probe(struct i2c_client * client)530 static int lm95245_probe(struct i2c_client *client)
531 {
532 struct device *dev = &client->dev;
533 struct lm95245_data *data;
534 struct device *hwmon_dev;
535 int ret;
536
537 data = devm_kzalloc(dev, sizeof(struct lm95245_data), GFP_KERNEL);
538 if (!data)
539 return -ENOMEM;
540
541 data->regmap = devm_regmap_init_i2c(client, &lm95245_regmap_config);
542 if (IS_ERR(data->regmap))
543 return PTR_ERR(data->regmap);
544
545 mutex_init(&data->update_lock);
546
547 /* Initialize the LM95245 chip */
548 ret = lm95245_init_client(data);
549 if (ret < 0)
550 return ret;
551
552 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
553 data,
554 &lm95245_chip_info,
555 NULL);
556 return PTR_ERR_OR_ZERO(hwmon_dev);
557 }
558
559 /* Driver data (common to all clients) */
560 static const struct i2c_device_id lm95245_id[] = {
561 { "lm95235" },
562 { "lm95245" },
563 { }
564 };
565 MODULE_DEVICE_TABLE(i2c, lm95245_id);
566
567 static const struct of_device_id __maybe_unused lm95245_of_match[] = {
568 { .compatible = "national,lm95235" },
569 { .compatible = "national,lm95245" },
570 { },
571 };
572 MODULE_DEVICE_TABLE(of, lm95245_of_match);
573
574 static struct i2c_driver lm95245_driver = {
575 .class = I2C_CLASS_HWMON,
576 .driver = {
577 .name = "lm95245",
578 .of_match_table = of_match_ptr(lm95245_of_match),
579 },
580 .probe = lm95245_probe,
581 .id_table = lm95245_id,
582 .detect = lm95245_detect,
583 .address_list = normal_i2c,
584 };
585
586 module_i2c_driver(lm95245_driver);
587
588 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
589 MODULE_DESCRIPTION("LM95235/LM95245 sensor driver");
590 MODULE_LICENSE("GPL");
591