1 /*
2 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
3 *
4 * Copyright (c) 2010 Ericsson AB.
5 *
6 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
7 *
8 * JC42.4 compliant temperature sensors are typically used on memory modules.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 */
24
25 #include <linux/module.h>
26 #include <linux/init.h>
27 #include <linux/slab.h>
28 #include <linux/jiffies.h>
29 #include <linux/i2c.h>
30 #include <linux/hwmon.h>
31 #include <linux/hwmon-sysfs.h>
32 #include <linux/err.h>
33 #include <linux/mutex.h>
34
35 /* Addresses to scan */
36 static const unsigned short normal_i2c[] = {
37 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
38
39 /* JC42 registers. All registers are 16 bit. */
40 #define JC42_REG_CAP 0x00
41 #define JC42_REG_CONFIG 0x01
42 #define JC42_REG_TEMP_UPPER 0x02
43 #define JC42_REG_TEMP_LOWER 0x03
44 #define JC42_REG_TEMP_CRITICAL 0x04
45 #define JC42_REG_TEMP 0x05
46 #define JC42_REG_MANID 0x06
47 #define JC42_REG_DEVICEID 0x07
48
49 /* Status bits in temperature register */
50 #define JC42_ALARM_CRIT_BIT 15
51 #define JC42_ALARM_MAX_BIT 14
52 #define JC42_ALARM_MIN_BIT 13
53
54 /* Configuration register defines */
55 #define JC42_CFG_CRIT_ONLY (1 << 2)
56 #define JC42_CFG_TCRIT_LOCK (1 << 6)
57 #define JC42_CFG_EVENT_LOCK (1 << 7)
58 #define JC42_CFG_SHUTDOWN (1 << 8)
59 #define JC42_CFG_HYST_SHIFT 9
60 #define JC42_CFG_HYST_MASK 0x03
61
62 /* Capabilities */
63 #define JC42_CAP_RANGE (1 << 2)
64
65 /* Manufacturer IDs */
66 #define ADT_MANID 0x11d4 /* Analog Devices */
67 #define ATMEL_MANID 0x001f /* Atmel */
68 #define MAX_MANID 0x004d /* Maxim */
69 #define IDT_MANID 0x00b3 /* IDT */
70 #define MCP_MANID 0x0054 /* Microchip */
71 #define NXP_MANID 0x1131 /* NXP Semiconductors */
72 #define ONS_MANID 0x1b09 /* ON Semiconductor */
73 #define STM_MANID 0x104a /* ST Microelectronics */
74
75 /* Supported chips */
76
77 /* Analog Devices */
78 #define ADT7408_DEVID 0x0801
79 #define ADT7408_DEVID_MASK 0xffff
80
81 /* Atmel */
82 #define AT30TS00_DEVID 0x8201
83 #define AT30TS00_DEVID_MASK 0xffff
84
85 /* IDT */
86 #define TS3000B3_DEVID 0x2903 /* Also matches TSE2002B3 */
87 #define TS3000B3_DEVID_MASK 0xffff
88
89 #define TS3000GB2_DEVID 0x2912 /* Also matches TSE2002GB2 */
90 #define TS3000GB2_DEVID_MASK 0xffff
91
92 /* Maxim */
93 #define MAX6604_DEVID 0x3e00
94 #define MAX6604_DEVID_MASK 0xffff
95
96 /* Microchip */
97 #define MCP9804_DEVID 0x0200
98 #define MCP9804_DEVID_MASK 0xfffc
99
100 #define MCP98242_DEVID 0x2000
101 #define MCP98242_DEVID_MASK 0xfffc
102
103 #define MCP98243_DEVID 0x2100
104 #define MCP98243_DEVID_MASK 0xfffc
105
106 #define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */
107 #define MCP9843_DEVID_MASK 0xfffe
108
109 /* NXP */
110 #define SE97_DEVID 0xa200
111 #define SE97_DEVID_MASK 0xfffc
112
113 #define SE98_DEVID 0xa100
114 #define SE98_DEVID_MASK 0xfffc
115
116 /* ON Semiconductor */
117 #define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */
118 #define CAT6095_DEVID_MASK 0xffe0
119
120 /* ST Microelectronics */
121 #define STTS424_DEVID 0x0101
122 #define STTS424_DEVID_MASK 0xffff
123
124 #define STTS424E_DEVID 0x0000
125 #define STTS424E_DEVID_MASK 0xfffe
126
127 #define STTS2002_DEVID 0x0300
128 #define STTS2002_DEVID_MASK 0xffff
129
130 #define STTS3000_DEVID 0x0200
131 #define STTS3000_DEVID_MASK 0xffff
132
133 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
134
135 struct jc42_chips {
136 u16 manid;
137 u16 devid;
138 u16 devid_mask;
139 };
140
141 static struct jc42_chips jc42_chips[] = {
142 { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
143 { ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
144 { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
145 { IDT_MANID, TS3000GB2_DEVID, TS3000GB2_DEVID_MASK },
146 { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
147 { MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
148 { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
149 { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
150 { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
151 { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
152 { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
153 { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
154 { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
155 { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
156 { STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
157 { STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
158 };
159
160 /* Each client has this additional data */
161 struct jc42_data {
162 struct device *hwmon_dev;
163 struct mutex update_lock; /* protect register access */
164 bool extended; /* true if extended range supported */
165 bool valid;
166 unsigned long last_updated; /* In jiffies */
167 u16 orig_config; /* original configuration */
168 u16 config; /* current configuration */
169 u16 temp_input; /* Temperatures */
170 u16 temp_crit;
171 u16 temp_min;
172 u16 temp_max;
173 };
174
175 static int jc42_probe(struct i2c_client *client,
176 const struct i2c_device_id *id);
177 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
178 static int jc42_remove(struct i2c_client *client);
179
180 static struct jc42_data *jc42_update_device(struct device *dev);
181
182 static const struct i2c_device_id jc42_id[] = {
183 { "jc42", 0 },
184 { }
185 };
186 MODULE_DEVICE_TABLE(i2c, jc42_id);
187
188 #ifdef CONFIG_PM
189
jc42_suspend(struct device * dev)190 static int jc42_suspend(struct device *dev)
191 {
192 struct i2c_client *client = to_i2c_client(dev);
193 struct jc42_data *data = i2c_get_clientdata(client);
194
195 data->config |= JC42_CFG_SHUTDOWN;
196 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
197 return 0;
198 }
199
jc42_resume(struct device * dev)200 static int jc42_resume(struct device *dev)
201 {
202 struct i2c_client *client = to_i2c_client(dev);
203 struct jc42_data *data = i2c_get_clientdata(client);
204
205 data->config &= ~JC42_CFG_SHUTDOWN;
206 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, data->config);
207 return 0;
208 }
209
210 static const struct dev_pm_ops jc42_dev_pm_ops = {
211 .suspend = jc42_suspend,
212 .resume = jc42_resume,
213 };
214
215 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
216 #else
217 #define JC42_DEV_PM_OPS NULL
218 #endif /* CONFIG_PM */
219
220 /* This is the driver that will be inserted */
221 static struct i2c_driver jc42_driver = {
222 .class = I2C_CLASS_SPD,
223 .driver = {
224 .name = "jc42",
225 .pm = JC42_DEV_PM_OPS,
226 },
227 .probe = jc42_probe,
228 .remove = jc42_remove,
229 .id_table = jc42_id,
230 .detect = jc42_detect,
231 .address_list = normal_i2c,
232 };
233
234 #define JC42_TEMP_MIN_EXTENDED (-40000)
235 #define JC42_TEMP_MIN 0
236 #define JC42_TEMP_MAX 125000
237
jc42_temp_to_reg(int temp,bool extended)238 static u16 jc42_temp_to_reg(int temp, bool extended)
239 {
240 int ntemp = SENSORS_LIMIT(temp,
241 extended ? JC42_TEMP_MIN_EXTENDED :
242 JC42_TEMP_MIN, JC42_TEMP_MAX);
243
244 /* convert from 0.001 to 0.0625 resolution */
245 return (ntemp * 2 / 125) & 0x1fff;
246 }
247
jc42_temp_from_reg(s16 reg)248 static int jc42_temp_from_reg(s16 reg)
249 {
250 reg &= 0x1fff;
251
252 /* sign extend register */
253 if (reg & 0x1000)
254 reg |= 0xf000;
255
256 /* convert from 0.0625 to 0.001 resolution */
257 return reg * 125 / 2;
258 }
259
260 /* sysfs stuff */
261
262 /* read routines for temperature limits */
263 #define show(value) \
264 static ssize_t show_##value(struct device *dev, \
265 struct device_attribute *attr, \
266 char *buf) \
267 { \
268 struct jc42_data *data = jc42_update_device(dev); \
269 if (IS_ERR(data)) \
270 return PTR_ERR(data); \
271 return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value)); \
272 }
273
274 show(temp_input);
275 show(temp_crit);
276 show(temp_min);
277 show(temp_max);
278
279 /* read routines for hysteresis values */
show_temp_crit_hyst(struct device * dev,struct device_attribute * attr,char * buf)280 static ssize_t show_temp_crit_hyst(struct device *dev,
281 struct device_attribute *attr, char *buf)
282 {
283 struct jc42_data *data = jc42_update_device(dev);
284 int temp, hyst;
285
286 if (IS_ERR(data))
287 return PTR_ERR(data);
288
289 temp = jc42_temp_from_reg(data->temp_crit);
290 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
291 & JC42_CFG_HYST_MASK];
292 return sprintf(buf, "%d\n", temp - hyst);
293 }
294
show_temp_max_hyst(struct device * dev,struct device_attribute * attr,char * buf)295 static ssize_t show_temp_max_hyst(struct device *dev,
296 struct device_attribute *attr, char *buf)
297 {
298 struct jc42_data *data = jc42_update_device(dev);
299 int temp, hyst;
300
301 if (IS_ERR(data))
302 return PTR_ERR(data);
303
304 temp = jc42_temp_from_reg(data->temp_max);
305 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
306 & JC42_CFG_HYST_MASK];
307 return sprintf(buf, "%d\n", temp - hyst);
308 }
309
310 /* write routines */
311 #define set(value, reg) \
312 static ssize_t set_##value(struct device *dev, \
313 struct device_attribute *attr, \
314 const char *buf, size_t count) \
315 { \
316 struct i2c_client *client = to_i2c_client(dev); \
317 struct jc42_data *data = i2c_get_clientdata(client); \
318 int err, ret = count; \
319 long val; \
320 if (kstrtol(buf, 10, &val) < 0) \
321 return -EINVAL; \
322 mutex_lock(&data->update_lock); \
323 data->value = jc42_temp_to_reg(val, data->extended); \
324 err = i2c_smbus_write_word_swapped(client, reg, data->value); \
325 if (err < 0) \
326 ret = err; \
327 mutex_unlock(&data->update_lock); \
328 return ret; \
329 }
330
331 set(temp_min, JC42_REG_TEMP_LOWER);
332 set(temp_max, JC42_REG_TEMP_UPPER);
333 set(temp_crit, JC42_REG_TEMP_CRITICAL);
334
335 /*
336 * JC42.4 compliant chips only support four hysteresis values.
337 * Pick best choice and go from there.
338 */
set_temp_crit_hyst(struct device * dev,struct device_attribute * attr,const char * buf,size_t count)339 static ssize_t set_temp_crit_hyst(struct device *dev,
340 struct device_attribute *attr,
341 const char *buf, size_t count)
342 {
343 struct i2c_client *client = to_i2c_client(dev);
344 struct jc42_data *data = i2c_get_clientdata(client);
345 unsigned long val;
346 int diff, hyst;
347 int err;
348 int ret = count;
349
350 if (kstrtoul(buf, 10, &val) < 0)
351 return -EINVAL;
352
353 diff = jc42_temp_from_reg(data->temp_crit) - val;
354 hyst = 0;
355 if (diff > 0) {
356 if (diff < 2250)
357 hyst = 1; /* 1.5 degrees C */
358 else if (diff < 4500)
359 hyst = 2; /* 3.0 degrees C */
360 else
361 hyst = 3; /* 6.0 degrees C */
362 }
363
364 mutex_lock(&data->update_lock);
365 data->config = (data->config
366 & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
367 | (hyst << JC42_CFG_HYST_SHIFT);
368 err = i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
369 data->config);
370 if (err < 0)
371 ret = err;
372 mutex_unlock(&data->update_lock);
373 return ret;
374 }
375
show_alarm(struct device * dev,struct device_attribute * attr,char * buf)376 static ssize_t show_alarm(struct device *dev,
377 struct device_attribute *attr, char *buf)
378 {
379 u16 bit = to_sensor_dev_attr(attr)->index;
380 struct jc42_data *data = jc42_update_device(dev);
381 u16 val;
382
383 if (IS_ERR(data))
384 return PTR_ERR(data);
385
386 val = data->temp_input;
387 if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
388 val = 0;
389 return sprintf(buf, "%u\n", (val >> bit) & 1);
390 }
391
392 static DEVICE_ATTR(temp1_input, S_IRUGO,
393 show_temp_input, NULL);
394 static DEVICE_ATTR(temp1_crit, S_IRUGO,
395 show_temp_crit, set_temp_crit);
396 static DEVICE_ATTR(temp1_min, S_IRUGO,
397 show_temp_min, set_temp_min);
398 static DEVICE_ATTR(temp1_max, S_IRUGO,
399 show_temp_max, set_temp_max);
400
401 static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
402 show_temp_crit_hyst, set_temp_crit_hyst);
403 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
404 show_temp_max_hyst, NULL);
405
406 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
407 JC42_ALARM_CRIT_BIT);
408 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
409 JC42_ALARM_MIN_BIT);
410 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
411 JC42_ALARM_MAX_BIT);
412
413 static struct attribute *jc42_attributes[] = {
414 &dev_attr_temp1_input.attr,
415 &dev_attr_temp1_crit.attr,
416 &dev_attr_temp1_min.attr,
417 &dev_attr_temp1_max.attr,
418 &dev_attr_temp1_crit_hyst.attr,
419 &dev_attr_temp1_max_hyst.attr,
420 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
421 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
422 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
423 NULL
424 };
425
jc42_attribute_mode(struct kobject * kobj,struct attribute * attr,int index)426 static umode_t jc42_attribute_mode(struct kobject *kobj,
427 struct attribute *attr, int index)
428 {
429 struct device *dev = container_of(kobj, struct device, kobj);
430 struct i2c_client *client = to_i2c_client(dev);
431 struct jc42_data *data = i2c_get_clientdata(client);
432 unsigned int config = data->config;
433 bool readonly;
434
435 if (attr == &dev_attr_temp1_crit.attr)
436 readonly = config & JC42_CFG_TCRIT_LOCK;
437 else if (attr == &dev_attr_temp1_min.attr ||
438 attr == &dev_attr_temp1_max.attr)
439 readonly = config & JC42_CFG_EVENT_LOCK;
440 else if (attr == &dev_attr_temp1_crit_hyst.attr)
441 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
442 else
443 readonly = true;
444
445 return S_IRUGO | (readonly ? 0 : S_IWUSR);
446 }
447
448 static const struct attribute_group jc42_group = {
449 .attrs = jc42_attributes,
450 .is_visible = jc42_attribute_mode,
451 };
452
453 /* Return 0 if detection is successful, -ENODEV otherwise */
jc42_detect(struct i2c_client * client,struct i2c_board_info * info)454 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
455 {
456 struct i2c_adapter *adapter = client->adapter;
457 int i, config, cap, manid, devid;
458
459 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
460 I2C_FUNC_SMBUS_WORD_DATA))
461 return -ENODEV;
462
463 cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
464 config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
465 manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
466 devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
467
468 if (cap < 0 || config < 0 || manid < 0 || devid < 0)
469 return -ENODEV;
470
471 if ((cap & 0xff00) || (config & 0xf800))
472 return -ENODEV;
473
474 for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
475 struct jc42_chips *chip = &jc42_chips[i];
476 if (manid == chip->manid &&
477 (devid & chip->devid_mask) == chip->devid) {
478 strlcpy(info->type, "jc42", I2C_NAME_SIZE);
479 return 0;
480 }
481 }
482 return -ENODEV;
483 }
484
jc42_probe(struct i2c_client * client,const struct i2c_device_id * id)485 static int jc42_probe(struct i2c_client *client, const struct i2c_device_id *id)
486 {
487 struct jc42_data *data;
488 int config, cap, err;
489 struct device *dev = &client->dev;
490
491 data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
492 if (!data)
493 return -ENOMEM;
494
495 i2c_set_clientdata(client, data);
496 mutex_init(&data->update_lock);
497
498 cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
499 if (cap < 0)
500 return cap;
501
502 data->extended = !!(cap & JC42_CAP_RANGE);
503
504 config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
505 if (config < 0)
506 return config;
507
508 data->orig_config = config;
509 if (config & JC42_CFG_SHUTDOWN) {
510 config &= ~JC42_CFG_SHUTDOWN;
511 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
512 }
513 data->config = config;
514
515 /* Register sysfs hooks */
516 err = sysfs_create_group(&dev->kobj, &jc42_group);
517 if (err)
518 return err;
519
520 data->hwmon_dev = hwmon_device_register(dev);
521 if (IS_ERR(data->hwmon_dev)) {
522 err = PTR_ERR(data->hwmon_dev);
523 goto exit_remove;
524 }
525
526 return 0;
527
528 exit_remove:
529 sysfs_remove_group(&dev->kobj, &jc42_group);
530 return err;
531 }
532
jc42_remove(struct i2c_client * client)533 static int jc42_remove(struct i2c_client *client)
534 {
535 struct jc42_data *data = i2c_get_clientdata(client);
536 hwmon_device_unregister(data->hwmon_dev);
537 sysfs_remove_group(&client->dev.kobj, &jc42_group);
538 if (data->config != data->orig_config)
539 i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG,
540 data->orig_config);
541 return 0;
542 }
543
jc42_update_device(struct device * dev)544 static struct jc42_data *jc42_update_device(struct device *dev)
545 {
546 struct i2c_client *client = to_i2c_client(dev);
547 struct jc42_data *data = i2c_get_clientdata(client);
548 struct jc42_data *ret = data;
549 int val;
550
551 mutex_lock(&data->update_lock);
552
553 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
554 val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP);
555 if (val < 0) {
556 ret = ERR_PTR(val);
557 goto abort;
558 }
559 data->temp_input = val;
560
561 val = i2c_smbus_read_word_swapped(client,
562 JC42_REG_TEMP_CRITICAL);
563 if (val < 0) {
564 ret = ERR_PTR(val);
565 goto abort;
566 }
567 data->temp_crit = val;
568
569 val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_LOWER);
570 if (val < 0) {
571 ret = ERR_PTR(val);
572 goto abort;
573 }
574 data->temp_min = val;
575
576 val = i2c_smbus_read_word_swapped(client, JC42_REG_TEMP_UPPER);
577 if (val < 0) {
578 ret = ERR_PTR(val);
579 goto abort;
580 }
581 data->temp_max = val;
582
583 data->last_updated = jiffies;
584 data->valid = true;
585 }
586 abort:
587 mutex_unlock(&data->update_lock);
588 return ret;
589 }
590
591 module_i2c_driver(jc42_driver);
592
593 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
594 MODULE_DESCRIPTION("JC42 driver");
595 MODULE_LICENSE("GPL");
596