?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
memcg: remove impossible conditional when committing
[linux-2.6.git] / drivers / hwmon / jc42.c
blob93499123706182b9bdf42b3da295759eda67b18c
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 MAX_MANID 0x004d /* Maxim */
68 #define IDT_MANID 0x00b3 /* IDT */
69 #define MCP_MANID 0x0054 /* Microchip */
70 #define NXP_MANID 0x1131 /* NXP Semiconductors */
71 #define ONS_MANID 0x1b09 /* ON Semiconductor */
72 #define STM_MANID 0x104a /* ST Microelectronics */
73
74 /* Supported chips */
75
76 /* Analog Devices */
77 #define ADT7408_DEVID 0x0801
78 #define ADT7408_DEVID_MASK 0xffff
79
80 /* IDT */
81 #define TS3000B3_DEVID 0x2903 /* Also matches TSE2002B3 */
82 #define TS3000B3_DEVID_MASK 0xffff
83
84 /* Maxim */
85 #define MAX6604_DEVID 0x3e00
86 #define MAX6604_DEVID_MASK 0xffff
87
88 /* Microchip */
89 #define MCP98242_DEVID 0x2000
90 #define MCP98242_DEVID_MASK 0xfffc
91
92 #define MCP98243_DEVID 0x2100
93 #define MCP98243_DEVID_MASK 0xfffc
94
95 #define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */
96 #define MCP9843_DEVID_MASK 0xfffe
97
98 /* NXP */
99 #define SE97_DEVID 0xa200
100 #define SE97_DEVID_MASK 0xfffc
101
102 #define SE98_DEVID 0xa100
103 #define SE98_DEVID_MASK 0xfffc
104
105 /* ON Semiconductor */
106 #define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */
107 #define CAT6095_DEVID_MASK 0xffe0
108
109 /* ST Microelectronics */
110 #define STTS424_DEVID 0x0101
111 #define STTS424_DEVID_MASK 0xffff
112
113 #define STTS424E_DEVID 0x0000
114 #define STTS424E_DEVID_MASK 0xfffe
115
116 static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
117
118 struct jc42_chips {
119 u16 manid;
120 u16 devid;
121 u16 devid_mask;
122 };
123
124 static struct jc42_chips jc42_chips[] = {
125 { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
126 { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
127 { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
128 { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
129 { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
130 { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
131 { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
132 { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
133 { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
134 { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
135 { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
136 };
137
138 /* Each client has this additional data */
139 struct jc42_data {
140 struct device *hwmon_dev;
141 struct mutex update_lock; /* protect register access */
142 bool extended; /* true if extended range supported */
143 bool valid;
144 unsigned long last_updated; /* In jiffies */
145 u16 orig_config; /* original configuration */
146 u16 config; /* current configuration */
147 u16 temp_input; /* Temperatures */
148 u16 temp_crit;
149 u16 temp_min;
150 u16 temp_max;
151 };
152
153 static int jc42_probe(struct i2c_client *client,
154 const struct i2c_device_id *id);
155 static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
156 static int jc42_remove(struct i2c_client *client);
157 static int jc42_read_value(struct i2c_client *client, u8 reg);
158 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value);
159
160 static struct jc42_data *jc42_update_device(struct device *dev);
161
162 static const struct i2c_device_id jc42_id[] = {
163 { "adt7408", 0 },
164 { "cat94ts02", 0 },
165 { "cat6095", 0 },
166 { "jc42", 0 },
167 { "max6604", 0 },
168 { "mcp9805", 0 },
169 { "mcp98242", 0 },
170 { "mcp98243", 0 },
171 { "mcp9843", 0 },
172 { "se97", 0 },
173 { "se97b", 0 },
174 { "se98", 0 },
175 { "stts424", 0 },
176 { "tse2002b3", 0 },
177 { "ts3000b3", 0 },
178 { }
179 };
180 MODULE_DEVICE_TABLE(i2c, jc42_id);
181
182 #ifdef CONFIG_PM
183
184 static int jc42_suspend(struct device *dev)
185 {
186 struct i2c_client *client = to_i2c_client(dev);
187 struct jc42_data *data = i2c_get_clientdata(client);
188
189 data->config |= JC42_CFG_SHUTDOWN;
190 jc42_write_value(client, JC42_REG_CONFIG, data->config);
191 return 0;
192 }
193
194 static int jc42_resume(struct device *dev)
195 {
196 struct i2c_client *client = to_i2c_client(dev);
197 struct jc42_data *data = i2c_get_clientdata(client);
198
199 data->config &= ~JC42_CFG_SHUTDOWN;
200 jc42_write_value(client, JC42_REG_CONFIG, data->config);
201 return 0;
202 }
203
204 static const struct dev_pm_ops jc42_dev_pm_ops = {
205 .suspend = jc42_suspend,
206 .resume = jc42_resume,
207 };
208
209 #define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
210 #else
211 #define JC42_DEV_PM_OPS NULL
212 #endif /* CONFIG_PM */
213
214 /* This is the driver that will be inserted */
215 static struct i2c_driver jc42_driver = {
216 .class = I2C_CLASS_HWMON,
217 .driver = {
218 .name = "jc42",
219 .pm = JC42_DEV_PM_OPS,
220 },
221 .probe = jc42_probe,
222 .remove = jc42_remove,
223 .id_table = jc42_id,
224 .detect = jc42_detect,
225 .address_list = normal_i2c,
226 };
227
228 #define JC42_TEMP_MIN_EXTENDED (-40000)
229 #define JC42_TEMP_MIN 0
230 #define JC42_TEMP_MAX 125000
231
232 static u16 jc42_temp_to_reg(int temp, bool extended)
233 {
234 int ntemp = SENSORS_LIMIT(temp,
235 extended ? JC42_TEMP_MIN_EXTENDED :
236 JC42_TEMP_MIN, JC42_TEMP_MAX);
237
238 /* convert from 0.001 to 0.0625 resolution */
239 return (ntemp * 2 / 125) & 0x1fff;
240 }
241
242 static int jc42_temp_from_reg(s16 reg)
243 {
244 reg &= 0x1fff;
245
246 /* sign extend register */
247 if (reg & 0x1000)
248 reg |= 0xf000;
249
250 /* convert from 0.0625 to 0.001 resolution */
251 return reg * 125 / 2;
252 }
253
254 /* sysfs stuff */
255
256 /* read routines for temperature limits */
257 #define show(value) \
258 static ssize_t show_##value(struct device *dev, \
259 struct device_attribute *attr, \
260 char *buf) \
261 { \
262 struct jc42_data *data = jc42_update_device(dev); \
263 if (IS_ERR(data)) \
264 return PTR_ERR(data); \
265 return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value)); \
266 }
267
268 show(temp_input);
269 show(temp_crit);
270 show(temp_min);
271 show(temp_max);
272
273 /* read routines for hysteresis values */
274 static ssize_t show_temp_crit_hyst(struct device *dev,
275 struct device_attribute *attr, char *buf)
276 {
277 struct jc42_data *data = jc42_update_device(dev);
278 int temp, hyst;
279
280 if (IS_ERR(data))
281 return PTR_ERR(data);
282
283 temp = jc42_temp_from_reg(data->temp_crit);
284 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
285 & JC42_CFG_HYST_MASK];
286 return sprintf(buf, "%d\n", temp - hyst);
287 }
288
289 static ssize_t show_temp_max_hyst(struct device *dev,
290 struct device_attribute *attr, char *buf)
291 {
292 struct jc42_data *data = jc42_update_device(dev);
293 int temp, hyst;
294
295 if (IS_ERR(data))
296 return PTR_ERR(data);
297
298 temp = jc42_temp_from_reg(data->temp_max);
299 hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
300 & JC42_CFG_HYST_MASK];
301 return sprintf(buf, "%d\n", temp - hyst);
302 }
303
304 /* write routines */
305 #define set(value, reg) \
306 static ssize_t set_##value(struct device *dev, \
307 struct device_attribute *attr, \
308 const char *buf, size_t count) \
309 { \
310 struct i2c_client *client = to_i2c_client(dev); \
311 struct jc42_data *data = i2c_get_clientdata(client); \
312 int err, ret = count; \
313 long val; \
314 if (strict_strtol(buf, 10, &val) < 0) \
315 return -EINVAL; \
316 mutex_lock(&data->update_lock); \
317 data->value = jc42_temp_to_reg(val, data->extended); \
318 err = jc42_write_value(client, reg, data->value); \
319 if (err < 0) \
320 ret = err; \
321 mutex_unlock(&data->update_lock); \
322 return ret; \
323 }
324
325 set(temp_min, JC42_REG_TEMP_LOWER);
326 set(temp_max, JC42_REG_TEMP_UPPER);
327 set(temp_crit, JC42_REG_TEMP_CRITICAL);
328
329 /* JC42.4 compliant chips only support four hysteresis values.
330 * Pick best choice and go from there. */
331 static ssize_t set_temp_crit_hyst(struct device *dev,
332 struct device_attribute *attr,
333 const char *buf, size_t count)
334 {
335 struct i2c_client *client = to_i2c_client(dev);
336 struct jc42_data *data = i2c_get_clientdata(client);
337 unsigned long val;
338 int diff, hyst;
339 int err;
340 int ret = count;
341
342 if (strict_strtoul(buf, 10, &val) < 0)
343 return -EINVAL;
344
345 diff = jc42_temp_from_reg(data->temp_crit) - val;
346 hyst = 0;
347 if (diff > 0) {
348 if (diff < 2250)
349 hyst = 1; /* 1.5 degrees C */
350 else if (diff < 4500)
351 hyst = 2; /* 3.0 degrees C */
352 else
353 hyst = 3; /* 6.0 degrees C */
354 }
355
356 mutex_lock(&data->update_lock);
357 data->config = (data->config
358 & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
359 | (hyst << JC42_CFG_HYST_SHIFT);
360 err = jc42_write_value(client, JC42_REG_CONFIG, data->config);
361 if (err < 0)
362 ret = err;
363 mutex_unlock(&data->update_lock);
364 return ret;
365 }
366
367 static ssize_t show_alarm(struct device *dev,
368 struct device_attribute *attr, char *buf)
369 {
370 u16 bit = to_sensor_dev_attr(attr)->index;
371 struct jc42_data *data = jc42_update_device(dev);
372 u16 val;
373
374 if (IS_ERR(data))
375 return PTR_ERR(data);
376
377 val = data->temp_input;
378 if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
379 val = 0;
380 return sprintf(buf, "%u\n", (val >> bit) & 1);
381 }
382
383 static DEVICE_ATTR(temp1_input, S_IRUGO,
384 show_temp_input, NULL);
385 static DEVICE_ATTR(temp1_crit, S_IRUGO,
386 show_temp_crit, set_temp_crit);
387 static DEVICE_ATTR(temp1_min, S_IRUGO,
388 show_temp_min, set_temp_min);
389 static DEVICE_ATTR(temp1_max, S_IRUGO,
390 show_temp_max, set_temp_max);
391
392 static DEVICE_ATTR(temp1_crit_hyst, S_IRUGO,
393 show_temp_crit_hyst, set_temp_crit_hyst);
394 static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
395 show_temp_max_hyst, NULL);
396
397 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
398 JC42_ALARM_CRIT_BIT);
399 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
400 JC42_ALARM_MIN_BIT);
401 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
402 JC42_ALARM_MAX_BIT);
403
404 static struct attribute *jc42_attributes[] = {
405 &dev_attr_temp1_input.attr,
406 &dev_attr_temp1_crit.attr,
407 &dev_attr_temp1_min.attr,
408 &dev_attr_temp1_max.attr,
409 &dev_attr_temp1_crit_hyst.attr,
410 &dev_attr_temp1_max_hyst.attr,
411 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
412 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
413 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
414 NULL
415 };
416
417 static mode_t jc42_attribute_mode(struct kobject *kobj,
418 struct attribute *attr, int index)
419 {
420 struct device *dev = container_of(kobj, struct device, kobj);
421 struct i2c_client *client = to_i2c_client(dev);
422 struct jc42_data *data = i2c_get_clientdata(client);
423 unsigned int config = data->config;
424 bool readonly;
425
426 if (attr == &dev_attr_temp1_crit.attr)
427 readonly = config & JC42_CFG_TCRIT_LOCK;
428 else if (attr == &dev_attr_temp1_min.attr ||
429 attr == &dev_attr_temp1_max.attr)
430 readonly = config & JC42_CFG_EVENT_LOCK;
431 else if (attr == &dev_attr_temp1_crit_hyst.attr)
432 readonly = config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK);
433 else
434 readonly = true;
435
436 return S_IRUGO | (readonly ? 0 : S_IWUSR);
437 }
438
439 static const struct attribute_group jc42_group = {
440 .attrs = jc42_attributes,
441 .is_visible = jc42_attribute_mode,
442 };
443
444 /* Return 0 if detection is successful, -ENODEV otherwise */
445 static int jc42_detect(struct i2c_client *new_client,
446 struct i2c_board_info *info)
447 {
448 struct i2c_adapter *adapter = new_client->adapter;
449 int i, config, cap, manid, devid;
450
451 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
452 I2C_FUNC_SMBUS_WORD_DATA))
453 return -ENODEV;
454
455 cap = jc42_read_value(new_client, JC42_REG_CAP);
456 config = jc42_read_value(new_client, JC42_REG_CONFIG);
457 manid = jc42_read_value(new_client, JC42_REG_MANID);
458 devid = jc42_read_value(new_client, JC42_REG_DEVICEID);
459
460 if (cap < 0 || config < 0 || manid < 0 || devid < 0)
461 return -ENODEV;
462
463 if ((cap & 0xff00) || (config & 0xf800))
464 return -ENODEV;
465
466 for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
467 struct jc42_chips *chip = &jc42_chips[i];
468 if (manid == chip->manid &&
469 (devid & chip->devid_mask) == chip->devid) {
470 strlcpy(info->type, "jc42", I2C_NAME_SIZE);
471 return 0;
472 }
473 }
474 return -ENODEV;
475 }
476
477 static int jc42_probe(struct i2c_client *new_client,
478 const struct i2c_device_id *id)
479 {
480 struct jc42_data *data;
481 int config, cap, err;
482
483 data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
484 if (!data) {
485 err = -ENOMEM;
486 goto exit;
487 }
488
489 i2c_set_clientdata(new_client, data);
490 mutex_init(&data->update_lock);
491
492 cap = jc42_read_value(new_client, JC42_REG_CAP);
493 if (cap < 0) {
494 err = -EINVAL;
495 goto exit_free;
496 }
497 data->extended = !!(cap & JC42_CAP_RANGE);
498
499 config = jc42_read_value(new_client, JC42_REG_CONFIG);
500 if (config < 0) {
501 err = -EINVAL;
502 goto exit_free;
503 }
504 data->orig_config = config;
505 if (config & JC42_CFG_SHUTDOWN) {
506 config &= ~JC42_CFG_SHUTDOWN;
507 jc42_write_value(new_client, JC42_REG_CONFIG, config);
508 }
509 data->config = config;
510
511 /* Register sysfs hooks */
512 err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
513 if (err)
514 goto exit_free;
515
516 data->hwmon_dev = hwmon_device_register(&new_client->dev);
517 if (IS_ERR(data->hwmon_dev)) {
518 err = PTR_ERR(data->hwmon_dev);
519 goto exit_remove;
520 }
521
522 return 0;
523
524 exit_remove:
525 sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
526 exit_free:
527 kfree(data);
528 exit:
529 return err;
530 }
531
532 static int jc42_remove(struct i2c_client *client)
533 {
534 struct jc42_data *data = i2c_get_clientdata(client);
535 hwmon_device_unregister(data->hwmon_dev);
536 sysfs_remove_group(&client->dev.kobj, &jc42_group);
537 if (data->config != data->orig_config)
538 jc42_write_value(client, JC42_REG_CONFIG, data->orig_config);
539 kfree(data);
540 return 0;
541 }
542
543 /* All registers are word-sized. */
544 static int jc42_read_value(struct i2c_client *client, u8 reg)
545 {
546 int ret = i2c_smbus_read_word_data(client, reg);
547 if (ret < 0)
548 return ret;
549 return swab16(ret);
550 }
551
552 static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value)
553 {
554 return i2c_smbus_write_word_data(client, reg, swab16(value));
555 }
556
557 static struct jc42_data *jc42_update_device(struct device *dev)
558 {
559 struct i2c_client *client = to_i2c_client(dev);
560 struct jc42_data *data = i2c_get_clientdata(client);
561 struct jc42_data *ret = data;
562 int val;
563
564 mutex_lock(&data->update_lock);
565
566 if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
567 val = jc42_read_value(client, JC42_REG_TEMP);
568 if (val < 0) {
569 ret = ERR_PTR(val);
570 goto abort;
571 }
572 data->temp_input = val;
573
574 val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL);
575 if (val < 0) {
576 ret = ERR_PTR(val);
577 goto abort;
578 }
579 data->temp_crit = val;
580
581 val = jc42_read_value(client, JC42_REG_TEMP_LOWER);
582 if (val < 0) {
583 ret = ERR_PTR(val);
584 goto abort;
585 }
586 data->temp_min = val;
587
588 val = jc42_read_value(client, JC42_REG_TEMP_UPPER);
589 if (val < 0) {
590 ret = ERR_PTR(val);
591 goto abort;
592 }
593 data->temp_max = val;
594
595 data->last_updated = jiffies;
596 data->valid = true;
597 }
598 abort:
599 mutex_unlock(&data->update_lock);
600 return ret;
601 }
602
603 static int __init sensors_jc42_init(void)
604 {
605 return i2c_add_driver(&jc42_driver);
606 }
607
608 static void __exit sensors_jc42_exit(void)
609 {
610 i2c_del_driver(&jc42_driver);
611 }
612
613 MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
614 MODULE_DESCRIPTION("JC42 driver");
615 MODULE_LICENSE("GPL");
616
617 module_init(sensors_jc42_init);
618 module_exit(sensors_jc42_exit);
Linus' kernel tree