1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
4 *
5 * Copyright (c) 2010 Ericsson AB.
6 *
7 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
8 *
9 * JC42.4 compliant temperature sensors are typically used on memory modules.
10 */
11
12 #include <linux/bitops.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/slab.h>
16 #include <linux/jiffies.h>
17 #include <linux/i2c.h>
18 #include <linux/hwmon.h>
19 #include <linux/err.h>
20 #include <linux/mutex.h>
21 #include <linux/of.h>
22
23 /* Addresses to scan */
24 static const unsigned short normal_i2c[] = {
25 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
26
27 /* JC42 registers. All registers are 16 bit. */
28 #define JC42_REG_CAP 0x00
29 #define JC42_REG_CONFIG 0x01
30 #define JC42_REG_TEMP_UPPER 0x02
31 #define JC42_REG_TEMP_LOWER 0x03
32 #define JC42_REG_TEMP_CRITICAL 0x04
33 #define JC42_REG_TEMP 0x05
34 #define JC42_REG_MANID 0x06
35 #define JC42_REG_DEVICEID 0x07
36 #define JC42_REG_SMBUS 0x22 /* NXP and Atmel, possibly others? */
37
38 /* Status bits in temperature register */
39 #define JC42_ALARM_CRIT_BIT 15
40 #define JC42_ALARM_MAX_BIT 14
41 #define JC42_ALARM_MIN_BIT 13
42
43 /* Configuration register defines */
44 #define JC42_CFG_CRIT_ONLY (1 << 2)
45 #define JC42_CFG_TCRIT_LOCK (1 << 6)
46 #define JC42_CFG_EVENT_LOCK (1 << 7)
47 #define JC42_CFG_SHUTDOWN (1 << 8)
48 #define JC42_CFG_HYST_SHIFT 9
49 #define JC42_CFG_HYST_MASK (0x03 << 9)
50
51 /* Capabilities */
52 #define JC42_CAP_RANGE (1 << 2)
53
54 /* Manufacturer IDs */
55 #define ADT_MANID 0x11d4 /* Analog Devices */
56 #define ATMEL_MANID 0x001f /* Atmel */
57 #define ATMEL_MANID2 0x1114 /* Atmel */
58 #define MAX_MANID 0x004d /* Maxim */
59 #define IDT_MANID 0x00b3 /* IDT */
60 #define MCP_MANID 0x0054 /* Microchip */
61 #define NXP_MANID 0x1131 /* NXP Semiconductors */
62 #define ONS_MANID 0x1b09 /* ON Semiconductor */
63 #define STM_MANID 0x104a /* ST Microelectronics */
64 #define GT_MANID 0x1c68 /* Giantec */
65 #define GT_MANID2 0x132d /* Giantec, 2nd mfg ID */
66
67 /* SMBUS register */
68 #define SMBUS_STMOUT BIT(7) /* SMBus time-out, active low */
69
70 /* Supported chips */
71
72 /* Analog Devices */
73 #define ADT7408_DEVID 0x0801
74 #define ADT7408_DEVID_MASK 0xffff
75
76 /* Atmel */
77 #define AT30TS00_DEVID 0x8201
78 #define AT30TS00_DEVID_MASK 0xffff
79
80 #define AT30TSE004_DEVID 0x2200
81 #define AT30TSE004_DEVID_MASK 0xffff
82
83 /* Giantec */
84 #define GT30TS00_DEVID 0x2200
85 #define GT30TS00_DEVID_MASK 0xff00
86
87 #define GT34TS02_DEVID 0x3300
88 #define GT34TS02_DEVID_MASK 0xff00
89
90 /* IDT */
91 #define TSE2004_DEVID 0x2200
92 #define TSE2004_DEVID_MASK 0xff00
93
94 #define TS3000_DEVID 0x2900 /* Also matches TSE2002 */
95 #define TS3000_DEVID_MASK 0xff00
96
97 #define TS3001_DEVID 0x3000
98 #define TS3001_DEVID_MASK 0xff00
99
100 /* Maxim */
101 #define MAX6604_DEVID 0x3e00
102 #define MAX6604_DEVID_MASK 0xffff
103
104 /* Microchip */
105 #define MCP9804_DEVID 0x0200
106 #define MCP9804_DEVID_MASK 0xfffc
107
108 #define MCP9808_DEVID 0x0400
109 #define MCP9808_DEVID_MASK 0xfffc
110
111 #define MCP98242_DEVID 0x2000
112 #define MCP98242_DEVID_MASK 0xfffc
113
114 #define MCP98243_DEVID 0x2100
115 #define MCP98243_DEVID_MASK 0xfffc
116
117 #define MCP98244_DEVID 0x2200
118 #define MCP98244_DEVID_MASK 0xfffc
119
120 #define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */
121 #define MCP9843_DEVID_MASK 0xfffe
122
123 /* NXP */
124 #define SE97_DEVID 0xa200
125 #define SE97_DEVID_MASK 0xfffc
126
127 #define SE98_DEVID 0xa100
128 #define SE98_DEVID_MASK 0xfffc
129
130 /* ON Semiconductor */
131 #define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */
132 #define CAT6095_DEVID_MASK 0xffe0
133
134 #define CAT34TS02C_DEVID 0x0a00
135 #define CAT34TS02C_DEVID_MASK 0xfff0
136
137 #define CAT34TS04_DEVID 0x2200
138 #define CAT34TS04_DEVID_MASK 0xfff0
139
140 /* ST Microelectronics */
141 #define STTS424_DEVID 0x0101
142 #define STTS424_DEVID_MASK 0xffff
143
144 #define STTS424E_DEVID 0x0000
145 #define STTS424E_DEVID_MASK 0xfffe
146
147 #define STTS2002_DEVID 0x0300
148 #define STTS2002_DEVID_MASK 0xffff
149
150 #define STTS2004_DEVID 0x2201
151 #define STTS2004_DEVID_MASK 0xffff
152
153 #define STTS3000_DEVID 0x0200
154 #define STTS3000_DEVID_MASK 0xffff
155
156 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
157
158 struct jc42_chips {
159 u16 manid;
160 u16 devid;
161 u16 devid_mask;
162 };
163
164 static struct jc42_chips jc42_chips[] = {
165 { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
166 { ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
167 { ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
168 { GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK },
169 { GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
170 { IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
171 { IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
172 { IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
173 { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
174 { MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
175 { MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK },
176 { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
177 { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
178 { MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
179 { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
180 { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
181 { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
182 { ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
183 { ONS_MANID, CAT34TS04_DEVID, CAT34TS04_DEVID_MASK },
184 { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
185 { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
186 { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
187 { STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
188 { STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
189 { STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
190 };
191
192 enum temp_index {
193 t_input = 0,
194 t_crit,
195 t_min,
196 t_max,
197 t_num_temp
198 };
199
200 static const u8 temp_regs[t_num_temp] = {
201 [t_input] = JC42_REG_TEMP,
202 [t_crit] = JC42_REG_TEMP_CRITICAL,
203 [t_min] = JC42_REG_TEMP_LOWER,
204 [t_max] = JC42_REG_TEMP_UPPER,
205 };
206
207 /* Each client has this additional data */
208 struct jc42_data {
209 struct i2c_client *client;
210 struct mutex update_lock; /* protect register access */
211 bool extended; /* true if extended range supported */
212 bool valid;
213 unsigned long last_updated; /* In jiffies */
214 u16 orig_config; /* original configuration */
215 u16 config; /* current configuration */
216 u16 temp[t_num_temp];/* Temperatures */
217 };
218
219 #define JC42_TEMP_MIN_EXTENDED (-40000)
220 #define JC42_TEMP_MIN 0
221 #define JC42_TEMP_MAX 125000
222
jc42_temp_to_reg(long temp,bool extended)223 static u16 jc42_temp_to_reg(long temp, bool extended)
224 {
225 int ntemp = clamp_val(temp,
226 extended ? JC42_TEMP_MIN_EXTENDED :
227 JC42_TEMP_MIN, JC42_TEMP_MAX);
228
229 /* convert from 0.001 to 0.0625 resolution */
230 return (ntemp * 2 / 125) & 0x1fff;
231 }
232
jc42_temp_from_reg(s16 reg)233 static int jc42_temp_from_reg(s16 reg)
234 {
235 reg = sign_extend32(reg, 12);
236
237 /* convert from 0.0625 to 0.001 resolution */
238 return reg * 125 / 2;
239 }
240
jc42_update_device(struct device * dev)241 static struct jc42_data *jc42_update_device(struct device *dev)
242 {
243 struct jc42_data *data = dev_get_drvdata(dev);
244 struct i2c_client *client = data->client;
245 struct jc42_data *ret = data;
246 int i, val;
247
248 mutex_lock(&data->update_lock);
249
250 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
251 for (i = 0; i < t_num_temp; i++) {
252 val = i2c_smbus_read_word_swapped(client, temp_regs[i]);
253 if (val < 0) {
254 ret = ERR_PTR(val);
255 goto abort;
256 }
257 data->temp[i] = val;
258 }
259 data->last_updated = jiffies;
260 data->valid = true;
261 }
262 abort:
263 mutex_unlock(&data->update_lock);
264 return ret;
265 }
266
jc42_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)267 static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
268 u32 attr, int channel, long *val)
269 {
270 struct jc42_data *data = jc42_update_device(dev);
271 int temp, hyst;
272
273 if (IS_ERR(data))
274 return PTR_ERR(data);
275
276 switch (attr) {
277 case hwmon_temp_input:
278 *val = jc42_temp_from_reg(data->temp[t_input]);
279 return 0;
280 case hwmon_temp_min:
281 *val = jc42_temp_from_reg(data->temp[t_min]);
282 return 0;
283 case hwmon_temp_max:
284 *val = jc42_temp_from_reg(data->temp[t_max]);
285 return 0;
286 case hwmon_temp_crit:
287 *val = jc42_temp_from_reg(data->temp[t_crit]);
288 return 0;
289 case hwmon_temp_max_hyst:
290 temp = jc42_temp_from_reg(data->temp[t_max]);
291 hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
292 >> JC42_CFG_HYST_SHIFT];
293 *val = temp - hyst;
294 return 0;
295 case hwmon_temp_crit_hyst:
296 temp = jc42_temp_from_reg(data->temp[t_crit]);
297 hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
298 >> JC42_CFG_HYST_SHIFT];
299 *val = temp - hyst;
300 return 0;
301 case hwmon_temp_min_alarm:
302 *val = (data->temp[t_input] >> JC42_ALARM_MIN_BIT) & 1;
303 return 0;
304 case hwmon_temp_max_alarm:
305 *val = (data->temp[t_input] >> JC42_ALARM_MAX_BIT) & 1;
306 return 0;
307 case hwmon_temp_crit_alarm:
308 *val = (data->temp[t_input] >> JC42_ALARM_CRIT_BIT) & 1;
309 return 0;
310 default:
311 return -EOPNOTSUPP;
312 }
313 }
314
jc42_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)315 static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
316 u32 attr, int channel, long val)
317 {
318 struct jc42_data *data = dev_get_drvdata(dev);
319 struct i2c_client *client = data->client;
320 int diff, hyst;
321 int ret;
322
323 mutex_lock(&data->update_lock);
324
325 switch (attr) {
326 case hwmon_temp_min:
327 data->temp[t_min] = jc42_temp_to_reg(val, data->extended);
328 ret = i2c_smbus_write_word_swapped(client, temp_regs[t_min],
329 data->temp[t_min]);
330 break;
331 case hwmon_temp_max:
332 data->temp[t_max] = jc42_temp_to_reg(val, data->extended);
333 ret = i2c_smbus_write_word_swapped(client, temp_regs[t_max],
334 data->temp[t_max]);
335 break;
336 case hwmon_temp_crit:
337 data->temp[t_crit] = jc42_temp_to_reg(val, data->extended);
338 ret = i2c_smbus_write_word_swapped(client, temp_regs[t_crit],
339 data->temp[t_crit]);
340 break;
341 case hwmon_temp_crit_hyst:
342 /*
343 * JC42.4 compliant chips only support four hysteresis values.
344 * Pick best choice and go from there.
345 */
346 val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED
347 : JC42_TEMP_MIN) - 6000,
348 JC42_TEMP_MAX);
349 diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
350 hyst = 0;
351 if (diff > 0) {
352 if (diff < 2250)
353 hyst = 1; /* 1.5 degrees C */
354 else if (diff < 4500)
355 hyst = 2; /* 3.0 degrees C */
356 else
357 hyst = 3; /* 6.0 degrees C */
358 }
359 data->config = (data->config & ~JC42_CFG_HYST_MASK) |
360 (hyst << JC42_CFG_HYST_SHIFT);
361 ret = i2c_smbus_write_word_swapped(data->client,
362 JC42_REG_CONFIG,
363 data->config);
364 break;
365 default:
366 ret = -EOPNOTSUPP;
367 break;
368 }
369
370 mutex_unlock(&data->update_lock);
371
372 return ret;
373 }
374
jc42_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)375 static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
376 u32 attr, int channel)
377 {
378 const struct jc42_data *data = _data;
379 unsigned int config = data->config;
380 umode_t mode = 0444;
381
382 switch (attr) {
383 case hwmon_temp_min:
384 case hwmon_temp_max:
385 if (!(config & JC42_CFG_EVENT_LOCK))
386 mode |= 0200;
387 break;
388 case hwmon_temp_crit:
389 if (!(config & JC42_CFG_TCRIT_LOCK))
390 mode |= 0200;
391 break;
392 case hwmon_temp_crit_hyst:
393 if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
394 mode |= 0200;
395 break;
396 case hwmon_temp_input:
397 case hwmon_temp_max_hyst:
398 case hwmon_temp_min_alarm:
399 case hwmon_temp_max_alarm:
400 case hwmon_temp_crit_alarm:
401 break;
402 default:
403 mode = 0;
404 break;
405 }
406 return mode;
407 }
408
409 /* Return 0 if detection is successful, -ENODEV otherwise */
jc42_detect(struct i2c_client * client,struct i2c_board_info * info)410 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
411 {
412 struct i2c_adapter *adapter = client->adapter;
413 int i, config, cap, manid, devid;
414
415 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
416 I2C_FUNC_SMBUS_WORD_DATA))
417 return -ENODEV;
418
419 cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
420 config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
421 manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
422 devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
423
424 if (cap < 0 || config < 0 || manid < 0 || devid < 0)
425 return -ENODEV;
426
427 if ((cap & 0xff00) || (config & 0xf800))
428 return -ENODEV;
429
430 for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
431 struct jc42_chips *chip = &jc42_chips[i];
432 if (manid == chip->manid &&
433 (devid & chip->devid_mask) == chip->devid) {
434 strlcpy(info->type, "jc42", I2C_NAME_SIZE);
435 return 0;
436 }
437 }
438 return -ENODEV;
439 }
440
441 static const struct hwmon_channel_info *jc42_info[] = {
442 HWMON_CHANNEL_INFO(temp,
443 HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX |
444 HWMON_T_CRIT | HWMON_T_MAX_HYST |
445 HWMON_T_CRIT_HYST | HWMON_T_MIN_ALARM |
446 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM),
447 NULL
448 };
449
450 static const struct hwmon_ops jc42_hwmon_ops = {
451 .is_visible = jc42_is_visible,
452 .read = jc42_read,
453 .write = jc42_write,
454 };
455
456 static const struct hwmon_chip_info jc42_chip_info = {
457 .ops = &jc42_hwmon_ops,
458 .info = jc42_info,
459 };
460
jc42_probe(struct i2c_client * client)461 static int jc42_probe(struct i2c_client *client)
462 {
463 struct device *dev = &client->dev;
464 struct device *hwmon_dev;
465 struct jc42_data *data;
466 int config, cap;
467
468 data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
469 if (!data)
470 return -ENOMEM;
471
472 data->client = client;
473 i2c_set_clientdata(client, data);
474 mutex_init(&data->update_lock);
475
476 cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
477 if (cap < 0)
478 return cap;
479
480 data->extended = !!(cap & JC42_CAP_RANGE);
481
482 if (device_property_read_bool(dev, "smbus-timeout-disable")) {
483 int smbus;
484
485 /*
486 * Not all chips support this register, but from a
487 * quick read of various datasheets no chip appears
488 * incompatible with the below attempt to disable
489 * the timeout. And the whole thing is opt-in...
490 */
491 smbus = i2c_smbus_read_word_swapped(client, JC42_REG_SMBUS);
492 if (smbus < 0)
493 return smbus;
494 i2c_smbus_write_word_swapped(client, JC42_REG_SMBUS,
495 smbus | SMBUS_STMOUT);
496 }
497
498 config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
499 if (config < 0)
500 return config;
501
502 data->orig_config = config;
503 if (config & JC42_CFG_SHUTDOWN) {
504 config &= ~JC42_CFG_SHUTDOWN;
505 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
506 }
507 data->config = config;
508
509 hwmon_dev = devm_hwmon_device_register_with_info(dev, "jc42",
510 data, &jc42_chip_info,
511 NULL);
512 return PTR_ERR_OR_ZERO(hwmon_dev);
513 }
514
jc42_remove(struct i2c_client * client)515 static int jc42_remove(struct i2c_client *client)
516 {
517 struct jc42_data *data = i2c_get_clientdata(client);
518
519 /* Restore original configuration except hysteresis */
520 if ((data->config & ~JC42_CFG_HYST_MASK) !=
521 (data->orig_config & ~JC42_CFG_HYST_MASK)) {
522 int config;
523
524 config = (data->orig_config & ~JC42_CFG_HYST_MASK)
525 | (data->config & JC42_CFG_HYST_MASK);
526 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
527 }
528 return 0;
529 }
530
531 #ifdef CONFIG_PM
532
jc42_suspend(struct device * dev)533 static int jc42_suspend(struct device *dev)
534 {
535 struct jc42_data *data = dev_get_drvdata(dev);
536
537 data->config |= JC42_CFG_SHUTDOWN;
538 i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
539 data->config);
540 return 0;
541 }
542
jc42_resume(struct device * dev)543 static int jc42_resume(struct device *dev)
544 {
545 struct jc42_data *data = dev_get_drvdata(dev);
546
547 data->config &= ~JC42_CFG_SHUTDOWN;
548 i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
549 data->config);
550 return 0;
551 }
552
553 static const struct dev_pm_ops jc42_dev_pm_ops = {
554 .suspend = jc42_suspend,
555 .resume = jc42_resume,
556 };
557
558 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
559 #else
560 #define JC42_DEV_PM_OPS NULL
561 #endif /* CONFIG_PM */
562
563 static const struct i2c_device_id jc42_id[] = {
564 { "jc42", 0 },
565 { }
566 };
567 MODULE_DEVICE_TABLE(i2c, jc42_id);
568
569 #ifdef CONFIG_OF
570 static const struct of_device_id jc42_of_ids[] = {
571 { .compatible = "jedec,jc-42.4-temp", },
572 { }
573 };
574 MODULE_DEVICE_TABLE(of, jc42_of_ids);
575 #endif
576
577 static struct i2c_driver jc42_driver = {
578 .class = I2C_CLASS_SPD | I2C_CLASS_HWMON,
579 .driver = {
580 .name = "jc42",
581 .pm = JC42_DEV_PM_OPS,
582 .of_match_table = of_match_ptr(jc42_of_ids),
583 },
584 .probe_new = jc42_probe,
585 .remove = jc42_remove,
586 .id_table = jc42_id,
587 .detect = jc42_detect,
588 .address_list = normal_i2c,
589 };
590
591 module_i2c_driver(jc42_driver);
592
593 MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
594 MODULE_DESCRIPTION("JC42 driver");
595 MODULE_LICENSE("GPL");
596