summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/lm95245.c
blob: 9a46c106a240230db8aaba95870e02447090cb5e (plain)
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
/*
 * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com>
 *
 * The LM95245 is a sensor chip made by National Semiconductors.
 * It reports up to two temperatures (its own plus an external one).
 * Complete datasheet can be obtained from National's website at:
 *   http://www.national.com/ds.cgi/LM/LM95245.pdf
 *
 * This driver is based on lm95241.c
 *
 * 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>
#include <linux/sysfs.h>

#define DEVNAME "lm95245"

static const unsigned short normal_i2c[] = {
	0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END };

/* LM95245 registers */
/* general registers */
#define LM95245_REG_RW_CONFIG1		0x03
#define LM95245_REG_RW_CONVERS_RATE	0x04
#define LM95245_REG_W_ONE_SHOT		0x0F

/* diode configuration */
#define LM95245_REG_RW_CONFIG2		0xBF
#define LM95245_REG_RW_REMOTE_OFFH	0x11
#define LM95245_REG_RW_REMOTE_OFFL	0x12

/* status registers */
#define LM95245_REG_R_STATUS1		0x02
#define LM95245_REG_R_STATUS2		0x33

/* limit registers */
#define LM95245_REG_RW_REMOTE_OS_LIMIT		0x07
#define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT	0x20
#define LM95245_REG_RW_REMOTE_TCRIT_LIMIT	0x19
#define LM95245_REG_RW_COMMON_HYSTERESIS	0x21

/* temperature signed */
#define LM95245_REG_R_LOCAL_TEMPH_S	0x00
#define LM95245_REG_R_LOCAL_TEMPL_S	0x30
#define LM95245_REG_R_REMOTE_TEMPH_S	0x01
#define LM95245_REG_R_REMOTE_TEMPL_S	0x10
/* temperature unsigned */
#define LM95245_REG_R_REMOTE_TEMPH_U	0x31
#define LM95245_REG_R_REMOTE_TEMPL_U	0x32

/* id registers */
#define LM95245_REG_R_MAN_ID		0xFE
#define LM95245_REG_R_CHIP_ID		0xFF

/* LM95245 specific bitfields */
#define CFG_STOP		0x40
#define CFG_REMOTE_TCRIT_MASK	0x10
#define CFG_REMOTE_OS_MASK	0x08
#define CFG_LOCAL_TCRIT_MASK	0x04
#define CFG_LOCAL_OS_MASK	0x02

#define CFG2_OS_A0		0x40
#define CFG2_DIODE_FAULT_OS	0x20
#define CFG2_DIODE_FAULT_TCRIT	0x10
#define CFG2_REMOTE_TT		0x08
#define CFG2_REMOTE_FILTER_DIS	0x00
#define CFG2_REMOTE_FILTER_EN	0x06

/* conversation rate in ms */
#define RATE_CR0063	0x00
#define RATE_CR0364	0x01
#define RATE_CR1000	0x02
#define RATE_CR2500	0x03

#define STATUS1_DIODE_FAULT	0x04
#define STATUS1_RTCRIT		0x02
#define STATUS1_LOC		0x01

#define MANUFACTURER_ID		0x01
#define DEFAULT_REVISION	0xB3

static const u8 lm95245_reg_address[] = {
	LM95245_REG_R_LOCAL_TEMPH_S,
	LM95245_REG_R_LOCAL_TEMPL_S,
	LM95245_REG_R_REMOTE_TEMPH_S,
	LM95245_REG_R_REMOTE_TEMPL_S,
	LM95245_REG_R_REMOTE_TEMPH_U,
	LM95245_REG_R_REMOTE_TEMPL_U,
	LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
	LM95245_REG_RW_REMOTE_TCRIT_LIMIT,
	LM95245_REG_RW_COMMON_HYSTERESIS,
	LM95245_REG_R_STATUS1,
};

/* Client data (each client gets its own) */
struct lm95245_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	unsigned long last_updated;	/* in jiffies */
	unsigned long interval;	/* in msecs */
	bool valid;		/* zero until following fields are valid */
	/* registers values */
	u8 regs[ARRAY_SIZE(lm95245_reg_address)];
	u8 config1, config2;
};

/* Conversions */
static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
{
	return val_h * 1000 + val_l * 1000 / 256;
}

static int temp_from_reg_signed(u8 val_h, u8 val_l)
{
	if (val_h & 0x80)
		return (val_h - 0x100) * 1000;
	return temp_from_reg_unsigned(val_h, val_l);
}

static struct lm95245_data *lm95245_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95245_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated
		+ msecs_to_jiffies(data->interval)) || !data->valid) {
		int i;

		dev_dbg(&client->dev, "Updating lm95245 data.\n");
		for (i = 0; i < ARRAY_SIZE(lm95245_reg_address); i++)
			data->regs[i]
			  = i2c_smbus_read_byte_data(client,
						     lm95245_reg_address[i]);
		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

static unsigned long lm95245_read_conversion_rate(struct i2c_client *client)
{
	int rate;
	unsigned long interval;

	rate = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONVERS_RATE);

	switch (rate) {
	case RATE_CR0063:
		interval = 63;
		break;
	case RATE_CR0364:
		interval = 364;
		break;
	case RATE_CR1000:
		interval = 1000;
		break;
	case RATE_CR2500:
	default:
		interval = 2500;
		break;
	}

	return interval;
}

static unsigned long lm95245_set_conversion_rate(struct i2c_client *client,
			unsigned long interval)
{
	int rate;

	if (interval <= 63) {
		interval = 63;
		rate = RATE_CR0063;
	} else if (interval <= 364) {
		interval = 364;
		rate = RATE_CR0364;
	} else if (interval <= 1000) {
		interval = 1000;
		rate = RATE_CR1000;
	} else {
		interval = 2500;
		rate = RATE_CR2500;
	}

	i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONVERS_RATE, rate);

	return interval;
}

/* Sysfs stuff */
static ssize_t show_input(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	struct lm95245_data *data = lm95245_update_device(dev);
	int temp;
	int index = to_sensor_dev_attr(attr)->index;

	/*
	 * Index 0 (Local temp) is always signed
	 * Index 2 (Remote temp) has both signed and unsigned data
	 * use signed calculation for remote if signed bit is set
	 */
	if (index == 0 || data->regs[index] & 0x80)
		temp = temp_from_reg_signed(data->regs[index],
			    data->regs[index + 1]);
	else
		temp = temp_from_reg_unsigned(data->regs[index + 2],
			    data->regs[index + 3]);

	return snprintf(buf, PAGE_SIZE - 1, "%d\n", temp);
}

static ssize_t show_limit(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct lm95245_data *data = lm95245_update_device(dev);
	int index = to_sensor_dev_attr(attr)->index;

	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
			data->regs[index] * 1000);
}

static ssize_t set_limit(struct device *dev, struct device_attribute *attr,
			const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95245_data *data = i2c_get_clientdata(client);
	int index = to_sensor_dev_attr(attr)->index;
	unsigned long val;

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

	val /= 1000;

	val = SENSORS_LIMIT(val, 0, (index == 6 ? 127 : 255));

	mutex_lock(&data->update_lock);

	data->valid = 0;

	i2c_smbus_write_byte_data(client, lm95245_reg_address[index], val);

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr,
			const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95245_data *data = i2c_get_clientdata(client);
	unsigned long val;

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

	val /= 1000;

	val = SENSORS_LIMIT(val, 0, 31);

	mutex_lock(&data->update_lock);

	data->valid = 0;

	/* shared crit hysteresis */
	i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS,
		val);

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t show_type(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95245_data *data = i2c_get_clientdata(client);

	return snprintf(buf, PAGE_SIZE - 1,
		data->config2 & CFG2_REMOTE_TT ? "1\n" : "2\n");
}

static ssize_t set_type(struct device *dev, struct device_attribute *attr,
			const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95245_data *data = i2c_get_clientdata(client);
	unsigned long val;

	if (kstrtoul(buf, 10, &val) < 0)
		return -EINVAL;
	if (val != 1 && val != 2)
		return -EINVAL;

	mutex_lock(&data->update_lock);

	if (val == 1)
		data->config2 |= CFG2_REMOTE_TT;
	else
		data->config2 &= ~CFG2_REMOTE_TT;

	data->valid = 0;

	i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2,
				  data->config2);

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct lm95245_data *data = lm95245_update_device(dev);
	int index = to_sensor_dev_attr(attr)->index;

	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
			!!(data->regs[9] & index));
}

static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct lm95245_data *data = lm95245_update_device(dev);

	return snprintf(buf, PAGE_SIZE - 1, "%lu\n", data->interval);
}

static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
			    const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95245_data *data = i2c_get_clientdata(client);
	unsigned long val;

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

	mutex_lock(&data->update_lock);

	data->interval = lm95245_set_conversion_rate(client, val);

	mutex_unlock(&data->update_lock);

	return count;
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit,
		set_limit, 6);
static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_limit,
		set_crit_hyst, 8);
static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
		STATUS1_LOC);

static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit,
		set_limit, 7);
static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_limit,
		set_crit_hyst, 8);
static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
		STATUS1_RTCRIT);
static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type,
		set_type, 0);
static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL,
		STATUS1_DIODE_FAULT);

static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
		set_interval);

static struct attribute *lm95245_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp1_crit.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp2_crit.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
	&sensor_dev_attr_temp2_type.dev_attr.attr,
	&sensor_dev_attr_temp2_fault.dev_attr.attr,
	&dev_attr_update_interval.attr,
	NULL
};

static const struct attribute_group lm95245_group = {
	.attrs = lm95245_attributes,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm95245_detect(struct i2c_client *new_client,
			  struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;

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

	if (i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID)
			!= MANUFACTURER_ID
		|| i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID)
			!= DEFAULT_REVISION)
		return -ENODEV;

	strlcpy(info->type, DEVNAME, I2C_NAME_SIZE);
	return 0;
}

static void lm95245_init_client(struct i2c_client *client)
{
	struct lm95245_data *data = i2c_get_clientdata(client);

	data->valid = 0;
	data->interval = lm95245_read_conversion_rate(client);

	data->config1 = i2c_smbus_read_byte_data(client,
		LM95245_REG_RW_CONFIG1);
	data->config2 = i2c_smbus_read_byte_data(client,
		LM95245_REG_RW_CONFIG2);

	if (data->config1 & CFG_STOP) {
		/* Clear the standby bit */
		data->config1 &= ~CFG_STOP;
		i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1,
			data->config1);
	}
}

static int lm95245_probe(struct i2c_client *new_client,
			 const struct i2c_device_id *id)
{
	struct lm95245_data *data;
	int err;

	data = kzalloc(sizeof(struct lm95245_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}

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

	/* Initialize the LM95245 chip */
	lm95245_init_client(new_client);

	/* Register sysfs hooks */
	err = sysfs_create_group(&new_client->dev.kobj, &lm95245_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_files;
	}

	return 0;

exit_remove_files:
	sysfs_remove_group(&new_client->dev.kobj, &lm95245_group);
exit_free:
	kfree(data);
exit:
	return err;
}

static int lm95245_remove(struct i2c_client *client)
{
	struct lm95245_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &lm95245_group);

	kfree(data);
	return 0;
}

/* Driver data (common to all clients) */
static const struct i2c_device_id lm95245_id[] = {
	{ DEVNAME, 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm95245_id);

static struct i2c_driver lm95245_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= DEVNAME,
	},
	.probe		= lm95245_probe,
	.remove		= lm95245_remove,
	.id_table	= lm95245_id,
	.detect		= lm95245_detect,
	.address_list	= normal_i2c,
};

module_i2c_driver(lm95245_driver);

MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
MODULE_DESCRIPTION("LM95245 sensor driver");
MODULE_LICENSE("GPL");
OpenPOWER on IntegriCloud