aboutsummaryrefslogblamecommitdiffstats
path: root/drivers/hwmon/jc42.c
blob: 340fc78c8ddedd9e73b697fde9479ec285e8bbcf (plain) (tree)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593















































































































































































































































































































































































































































































































































































































                                                                               
/*
 * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
 *
 * Copyright (c) 2010  Ericsson AB.
 *
 * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
 *
 * JC42.4 compliant temperature sensors are typically used on memory modules.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = {
	0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };

/* JC42 registers. All registers are 16 bit. */
#define JC42_REG_CAP		0x00
#define JC42_REG_CONFIG		0x01
#define JC42_REG_TEMP_UPPER	0x02
#define JC42_REG_TEMP_LOWER	0x03
#define JC42_REG_TEMP_CRITICAL	0x04
#define JC42_REG_TEMP		0x05
#define JC42_REG_MANID		0x06
#define JC42_REG_DEVICEID	0x07

/* Status bits in temperature register */
#define JC42_ALARM_CRIT_BIT	15
#define JC42_ALARM_MAX_BIT	14
#define JC42_ALARM_MIN_BIT	13

/* Configuration register defines */
#define JC42_CFG_CRIT_ONLY	(1 << 2)
#define JC42_CFG_SHUTDOWN	(1 << 8)
#define JC42_CFG_HYST_SHIFT	9
#define JC42_CFG_HYST_MASK	0x03

/* Capabilities */
#define JC42_CAP_RANGE		(1 << 2)

/* Manufacturer IDs */
#define ADT_MANID		0x11d4  /* Analog Devices */
#define MAX_MANID		0x004d  /* Maxim */
#define IDT_MANID		0x00b3  /* IDT */
#define MCP_MANID		0x0054  /* Microchip */
#define NXP_MANID		0x1131  /* NXP Semiconductors */
#define ONS_MANID		0x1b09  /* ON Semiconductor */
#define STM_MANID		0x104a  /* ST Microelectronics */

/* Supported chips */

/* Analog Devices */
#define ADT7408_DEVID		0x0801
#define ADT7408_DEVID_MASK	0xffff

/* IDT */
#define TS3000B3_DEVID		0x2903  /* Also matches TSE2002B3 */
#define TS3000B3_DEVID_MASK	0xffff

/* Maxim */
#define MAX6604_DEVID		0x3e00
#define MAX6604_DEVID_MASK	0xffff

/* Microchip */
#define MCP98242_DEVID		0x2000
#define MCP98242_DEVID_MASK	0xfffc

#define MCP98243_DEVID		0x2100
#define MCP98243_DEVID_MASK	0xfffc

#define MCP9843_DEVID		0x0000	/* Also matches mcp9805 */
#define MCP9843_DEVID_MASK	0xfffe

/* NXP */
#define SE97_DEVID		0xa200
#define SE97_DEVID_MASK		0xfffc

#define SE98_DEVID		0xa100
#define SE98_DEVID_MASK		0xfffc

/* ON Semiconductor */
#define CAT6095_DEVID		0x0800	/* Also matches CAT34TS02 */
#define CAT6095_DEVID_MASK	0xffe0

/* ST Microelectronics */
#define STTS424_DEVID		0x0101
#define STTS424_DEVID_MASK	0xffff

#define STTS424E_DEVID		0x0000
#define STTS424E_DEVID_MASK	0xfffe

static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };

struct jc42_chips {
	u16 manid;
	u16 devid;
	u16 devid_mask;
};

static struct jc42_chips jc42_chips[] = {
	{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
	{ IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
	{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
	{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
	{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
	{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
	{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
	{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
	{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
	{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
	{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
};

/* Each client has this additional data */
struct jc42_data {
	struct device	*hwmon_dev;
	struct mutex	update_lock;	/* protect register access */
	bool		extended;	/* true if extended range supported */
	bool		valid;
	unsigned long	last_updated;	/* In jiffies */
	u16		orig_config;	/* original configuration */
	u16		config;		/* current configuration */
	u16		temp_input;	/* Temperatures */
	u16		temp_crit;
	u16		temp_min;
	u16		temp_max;
};

static int jc42_probe(struct i2c_client *client,
		      const struct i2c_device_id *id);
static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
static int jc42_remove(struct i2c_client *client);
static int jc42_read_value(struct i2c_client *client, u8 reg);
static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value);

static struct jc42_data *jc42_update_device(struct device *dev);

static const struct i2c_device_id jc42_id[] = {
	{ "adt7408", 0 },
	{ "cat94ts02", 0 },
	{ "cat6095", 0 },
	{ "jc42", 0 },
	{ "max6604", 0 },
	{ "mcp9805", 0 },
	{ "mcp98242", 0 },
	{ "mcp98243", 0 },
	{ "mcp9843", 0 },
	{ "se97", 0 },
	{ "se97b", 0 },
	{ "se98", 0 },
	{ "stts424", 0 },
	{ "tse2002b3", 0 },
	{ "ts3000b3", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, jc42_id);

#ifdef CONFIG_PM

static int jc42_suspend(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);

	data->config |= JC42_CFG_SHUTDOWN;
	jc42_write_value(client, JC42_REG_CONFIG, data->config);
	return 0;
}

static int jc42_resume(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);

	data->config &= ~JC42_CFG_SHUTDOWN;
	jc42_write_value(client, JC42_REG_CONFIG, data->config);
	return 0;
}

static const struct dev_pm_ops jc42_dev_pm_ops = {
	.suspend = jc42_suspend,
	.resume = jc42_resume,
};

#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
#else
#define JC42_DEV_PM_OPS NULL
#endif /* CONFIG_PM */

/* This is the driver that will be inserted */
static struct i2c_driver jc42_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "jc42",
		.pm = JC42_DEV_PM_OPS,
	},
	.probe		= jc42_probe,
	.remove		= jc42_remove,
	.id_table	= jc42_id,
	.detect		= jc42_detect,
	.address_list	= normal_i2c,
};

#define JC42_TEMP_MIN_EXTENDED	(-40000)
#define JC42_TEMP_MIN		0
#define JC42_TEMP_MAX		125000

static u16 jc42_temp_to_reg(int temp, bool extended)
{
	int ntemp = SENSORS_LIMIT(temp,
				  extended ? JC42_TEMP_MIN_EXTENDED :
				  JC42_TEMP_MIN, JC42_TEMP_MAX);

	/* convert from 0.001 to 0.0625 resolution */
	return (ntemp * 2 / 125) & 0x1fff;
}

static int jc42_temp_from_reg(s16 reg)
{
	reg &= 0x1fff;

	/* sign extend register */
	if (reg & 0x1000)
		reg |= 0xf000;

	/* convert from 0.0625 to 0.001 resolution */
	return reg * 125 / 2;
}

/* sysfs stuff */

/* read routines for temperature limits */
#define show(value)	\
static ssize_t show_##value(struct device *dev,				\
			    struct device_attribute *attr,		\
			    char *buf)					\
{									\
	struct jc42_data *data = jc42_update_device(dev);		\
	if (IS_ERR(data))						\
		return PTR_ERR(data);					\
	return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));	\
}

show(temp_input);
show(temp_crit);
show(temp_min);
show(temp_max);

/* read routines for hysteresis values */
static ssize_t show_temp_crit_hyst(struct device *dev,
				   struct device_attribute *attr, char *buf)
{
	struct jc42_data *data = jc42_update_device(dev);
	int temp, hyst;

	if (IS_ERR(data))
		return PTR_ERR(data);

	temp = jc42_temp_from_reg(data->temp_crit);
	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
			       & JC42_CFG_HYST_MASK];
	return sprintf(buf, "%d\n", temp - hyst);
}

static ssize_t show_temp_max_hyst(struct device *dev,
				  struct device_attribute *attr, char *buf)
{
	struct jc42_data *data = jc42_update_device(dev);
	int temp, hyst;

	if (IS_ERR(data))
		return PTR_ERR(data);

	temp = jc42_temp_from_reg(data->temp_max);
	hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
			       & JC42_CFG_HYST_MASK];
	return sprintf(buf, "%d\n", temp - hyst);
}

/* write routines */
#define set(value, reg)	\
static ssize_t set_##value(struct device *dev,				\
			   struct device_attribute *attr,		\
			   const char *buf, size_t count)		\
{									\
	struct i2c_client *client = to_i2c_client(dev);			\
	struct jc42_data *data = i2c_get_clientdata(client);		\
	int err, ret = count;						\
	long val;							\
	if (strict_strtol(buf, 10, &val) < 0)				\
		return -EINVAL;						\
	mutex_lock(&data->update_lock);					\
	data->value = jc42_temp_to_reg(val, data->extended);		\
	err = jc42_write_value(client, reg, data->value);		\
	if (err < 0)							\
		ret = err;						\
	mutex_unlock(&data->update_lock);				\
	return ret;							\
}

set(temp_min, JC42_REG_TEMP_LOWER);
set(temp_max, JC42_REG_TEMP_UPPER);
set(temp_crit, JC42_REG_TEMP_CRITICAL);

/* JC42.4 compliant chips only support four hysteresis values.
 * Pick best choice and go from there. */
static ssize_t set_temp_crit_hyst(struct device *dev,
				  struct device_attribute *attr,
				  const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);
	long val;
	int diff, hyst;
	int err;
	int ret = count;

	if (strict_strtoul(buf, 10, &val) < 0)
		return -EINVAL;

	diff = jc42_temp_from_reg(data->temp_crit) - val;
	hyst = 0;
	if (diff > 0) {
		if (diff < 2250)
			hyst = 1;	/* 1.5 degrees C */
		else if (diff < 4500)
			hyst = 2;	/* 3.0 degrees C */
		else
			hyst = 3;	/* 6.0 degrees C */
	}

	mutex_lock(&data->update_lock);
	data->config = (data->config
			& ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
	  | (hyst << JC42_CFG_HYST_SHIFT);
	err = jc42_write_value(client, JC42_REG_CONFIG, data->config);
	if (err < 0)
		ret = err;
	mutex_unlock(&data->update_lock);
	return ret;
}

static ssize_t show_alarm(struct device *dev,
			  struct device_attribute *attr, char *buf)
{
	u16 bit = to_sensor_dev_attr(attr)->index;
	struct jc42_data *data = jc42_update_device(dev);
	u16 val;

	if (IS_ERR(data))
		return PTR_ERR(data);

	val = data->temp_input;
	if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
		val = 0;
	return sprintf(buf, "%u\n", (val >> bit) & 1);
}

static DEVICE_ATTR(temp1_input, S_IRUGO,
		   show_temp_input, NULL);
static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
		   show_temp_crit, set_temp_crit);
static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
		   show_temp_min, set_temp_min);
static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
		   show_temp_max, set_temp_max);

static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
		   show_temp_crit_hyst, set_temp_crit_hyst);
static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
		   show_temp_max_hyst, NULL);

static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
			  JC42_ALARM_CRIT_BIT);
static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
			  JC42_ALARM_MIN_BIT);
static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
			  JC42_ALARM_MAX_BIT);

static struct attribute *jc42_attributes[] = {
	&dev_attr_temp1_input.attr,
	&dev_attr_temp1_crit.attr,
	&dev_attr_temp1_min.attr,
	&dev_attr_temp1_max.attr,
	&dev_attr_temp1_crit_hyst.attr,
	&dev_attr_temp1_max_hyst.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
	NULL
};

static const struct attribute_group jc42_group = {
	.attrs = jc42_attributes,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int jc42_detect(struct i2c_client *new_client,
		       struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;
	int i, config, cap, manid, devid;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
				     I2C_FUNC_SMBUS_WORD_DATA))
		return -ENODEV;

	cap = jc42_read_value(new_client, JC42_REG_CAP);
	config = jc42_read_value(new_client, JC42_REG_CONFIG);
	manid = jc42_read_value(new_client, JC42_REG_MANID);
	devid = jc42_read_value(new_client, JC42_REG_DEVICEID);

	if (cap < 0 || config < 0 || manid < 0 || devid < 0)
		return -ENODEV;

	if ((cap & 0xff00) || (config & 0xf800))
		return -ENODEV;

	for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
		struct jc42_chips *chip = &jc42_chips[i];
		if (manid == chip->manid &&
		    (devid & chip->devid_mask) == chip->devid) {
			strlcpy(info->type, "jc42", I2C_NAME_SIZE);
			return 0;
		}
	}
	return -ENODEV;
}

static int jc42_probe(struct i2c_client *new_client,
		      const struct i2c_device_id *id)
{
	struct jc42_data *data;
	int config, cap, err;

	data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}

	i2c_set_clientdata(new_client, data);
	mutex_init(&data->update_lock);

	cap = jc42_read_value(new_client, JC42_REG_CAP);
	if (cap < 0) {
		err = -EINVAL;
		goto exit_free;
	}
	data->extended = !!(cap & JC42_CAP_RANGE);

	config = jc42_read_value(new_client, JC42_REG_CONFIG);
	if (config < 0) {
		err = -EINVAL;
		goto exit_free;
	}
	data->orig_config = config;
	if (config & JC42_CFG_SHUTDOWN) {
		config &= ~JC42_CFG_SHUTDOWN;
		jc42_write_value(new_client, JC42_REG_CONFIG, config);
	}
	data->config = config;

	/* Register sysfs hooks */
	err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
	if (err)
		goto exit_free;

	data->hwmon_dev = hwmon_device_register(&new_client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		err = PTR_ERR(data->hwmon_dev);
		goto exit_remove;
	}

	return 0;

exit_remove:
	sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
exit_free:
	kfree(data);
exit:
	return err;
}

static int jc42_remove(struct i2c_client *client)
{
	struct jc42_data *data = i2c_get_clientdata(client);
	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &jc42_group);
	if (data->config != data->orig_config)
		jc42_write_value(client, JC42_REG_CONFIG, data->orig_config);
	kfree(data);
	return 0;
}

/* All registers are word-sized. */
static int jc42_read_value(struct i2c_client *client, u8 reg)
{
	int ret = i2c_smbus_read_word_data(client, reg);
	if (ret < 0)
		return ret;
	return swab16(ret);
}

static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value)
{
	return i2c_smbus_write_word_data(client, reg, swab16(value));
}

static struct jc42_data *jc42_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct jc42_data *data = i2c_get_clientdata(client);
	struct jc42_data *ret = data;
	int val;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
		val = jc42_read_value(client, JC42_REG_TEMP);
		if (val < 0) {
			ret = ERR_PTR(val);
			goto abort;
		}
		data->temp_input = val;

		val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL);
		if (val < 0) {
			ret = ERR_PTR(val);
			goto abort;
		}
		data->temp_crit = val;

		val = jc42_read_value(client, JC42_REG_TEMP_LOWER);
		if (val < 0) {
			ret = ERR_PTR(val);
			goto abort;
		}
		data->temp_min = val;

		val = jc42_read_value(client, JC42_REG_TEMP_UPPER);
		if (val < 0) {
			ret = ERR_PTR(val);
			goto abort;
		}
		data->temp_max = val;

		data->last_updated = jiffies;
		data->valid = true;
	}
abort:
	mutex_unlock(&data->update_lock);
	return ret;
}

static int __init sensors_jc42_init(void)
{
	return i2c_add_driver(&jc42_driver);
}

static void __exit sensors_jc42_exit(void)
{
	i2c_del_driver(&jc42_driver);
}

MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
MODULE_DESCRIPTION("JC42 driver");
MODULE_LICENSE("GPL");

module_init(sensors_jc42_init);
module_exit(sensors_jc42_exit);