aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/lm95241.c
blob: 1a6dfb6df1e7ff121ce4903ab80f1b2e57ba2ef1 (plain) (blame)
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
/*
 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
 *
 * The LM95241 is a sensor chip made by National Semiconductors.
 * It reports up to three temperatures (its own plus up to two external ones).
 * Complete datasheet can be obtained from National's website at:
 *   http://www.national.com/ds.cgi/LM/LM95241.pdf
 *
 * 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 "lm95241"

static const unsigned short normal_i2c[] = {
	0x19, 0x2a, 0x2b, I2C_CLIENT_END };

/* LM95241 registers */
#define LM95241_REG_R_MAN_ID		0xFE
#define LM95241_REG_R_CHIP_ID		0xFF
#define LM95241_REG_R_STATUS		0x02
#define LM95241_REG_RW_CONFIG		0x03
#define LM95241_REG_RW_REM_FILTER	0x06
#define LM95241_REG_RW_TRUTHERM		0x07
#define LM95241_REG_W_ONE_SHOT		0x0F
#define LM95241_REG_R_LOCAL_TEMPH	0x10
#define LM95241_REG_R_REMOTE1_TEMPH	0x11
#define LM95241_REG_R_REMOTE2_TEMPH	0x12
#define LM95241_REG_R_LOCAL_TEMPL	0x20
#define LM95241_REG_R_REMOTE1_TEMPL	0x21
#define LM95241_REG_R_REMOTE2_TEMPL	0x22
#define LM95241_REG_RW_REMOTE_MODEL	0x30

/* LM95241 specific bitfields */
#define CFG_STOP 0x40
#define CFG_CR0076 0x00
#define CFG_CR0182 0x10
#define CFG_CR1000 0x20
#define CFG_CR2700 0x30
#define R1MS_SHIFT 0
#define R2MS_SHIFT 2
#define R1MS_MASK (0x01 << (R1MS_SHIFT))
#define R2MS_MASK (0x01 << (R2MS_SHIFT))
#define R1DF_SHIFT 1
#define R2DF_SHIFT 2
#define R1DF_MASK (0x01 << (R1DF_SHIFT))
#define R2DF_MASK (0x01 << (R2DF_SHIFT))
#define R1FE_MASK 0x01
#define R2FE_MASK 0x05
#define TT1_SHIFT 0
#define TT2_SHIFT 4
#define TT_OFF 0
#define TT_ON 1
#define TT_MASK 7
#define MANUFACTURER_ID 0x01
#define DEFAULT_REVISION 0xA4

static const u8 lm95241_reg_address[] = {
	LM95241_REG_R_LOCAL_TEMPH,
	LM95241_REG_R_LOCAL_TEMPL,
	LM95241_REG_R_REMOTE1_TEMPH,
	LM95241_REG_R_REMOTE1_TEMPL,
	LM95241_REG_R_REMOTE2_TEMPH,
	LM95241_REG_R_REMOTE2_TEMPL
};

/* Client data (each client gets its own) */
struct lm95241_data {
	struct device *hwmon_dev;
	struct mutex update_lock;
	unsigned long last_updated, interval;	/* in jiffies */
	char valid;		/* zero until following fields are valid */
	/* registers values */
	u8 temp[ARRAY_SIZE(lm95241_reg_address)];
	u8 config, model, trutherm;
};

/* Conversions */
static int TempFromReg(u8 val_h, u8 val_l)
{
	if (val_h & 0x80)
		return val_h - 0x100;
	return val_h * 1000 + val_l * 1000 / 256;
}

static struct lm95241_data *lm95241_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95241_data *data = i2c_get_clientdata(client);

	mutex_lock(&data->update_lock);

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

		dev_dbg(&client->dev, "Updating lm95241 data.\n");
		for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
			data->temp[i]
			  = i2c_smbus_read_byte_data(client,
						     lm95241_reg_address[i]);
		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

/* Sysfs stuff */
static ssize_t show_input(struct device *dev, struct device_attribute *attr,
			  char *buf)
{
	struct lm95241_data *data = lm95241_update_device(dev);

	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
		TempFromReg(data->temp[to_sensor_dev_attr(attr)->index],
			    data->temp[to_sensor_dev_attr(attr)->index + 1]));
}

static ssize_t show_type(struct device *dev, struct device_attribute *attr,
			 char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95241_data *data = i2c_get_clientdata(client);

	return snprintf(buf, PAGE_SIZE - 1,
		data->model & to_sensor_dev_attr(attr)->index ? "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 lm95241_data *data = i2c_get_clientdata(client);
	unsigned long val;
	int shift;
	u8 mask = to_sensor_dev_attr(attr)->index;

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

	shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;

	mutex_lock(&data->update_lock);

	data->trutherm &= ~(TT_MASK << shift);
	if (val == 1) {
		data->model |= mask;
		data->trutherm |= (TT_ON << shift);
	} else {
		data->model &= ~mask;
		data->trutherm |= (TT_OFF << shift);
	}
	data->valid = 0;

	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
				  data->model);
	i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
				  data->trutherm);

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t show_min(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95241_data *data = i2c_get_clientdata(client);

	return snprintf(buf, PAGE_SIZE - 1,
			data->config & to_sensor_dev_attr(attr)->index ?
			"-127000\n" : "0\n");
}

static ssize_t set_min(struct device *dev, struct device_attribute *attr,
		       const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95241_data *data = i2c_get_clientdata(client);
	long val;

	if (strict_strtol(buf, 10, &val) < 0)
		return -EINVAL;
	if (val < -128000)
		return -EINVAL;

	mutex_lock(&data->update_lock);

	if (val < 0)
		data->config |= to_sensor_dev_attr(attr)->index;
	else
		data->config &= ~to_sensor_dev_attr(attr)->index;
	data->valid = 0;

	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t show_max(struct device *dev, struct device_attribute *attr,
			char *buf)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95241_data *data = i2c_get_clientdata(client);

	return snprintf(buf, PAGE_SIZE - 1,
			data->config & to_sensor_dev_attr(attr)->index ?
			"127000\n" : "255000\n");
}

static ssize_t set_max(struct device *dev, struct device_attribute *attr,
		       const char *buf, size_t count)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct lm95241_data *data = i2c_get_clientdata(client);
	long val;

	if (strict_strtol(buf, 10, &val) < 0)
		return -EINVAL;
	if (val >= 256000)
		return -EINVAL;

	mutex_lock(&data->update_lock);

	if (val <= 127000)
		data->config |= to_sensor_dev_attr(attr)->index;
	else
		data->config &= ~to_sensor_dev_attr(attr)->index;
	data->valid = 0;

	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);

	mutex_unlock(&data->update_lock);

	return count;
}

static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
			     char *buf)
{
	struct lm95241_data *data = lm95241_update_device(dev);

	return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
			/ HZ);
}

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 lm95241_data *data = i2c_get_clientdata(client);
	unsigned long val;

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

	data->interval = val * HZ / 1000;

	return count;
}

static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
			  R1MS_MASK);
static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
			  R2MS_MASK);
static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
			  R1DF_MASK);
static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
			  R2DF_MASK);
static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
			  R1DF_MASK);
static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
			  R2DF_MASK);
static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
		   set_interval);

static struct attribute *lm95241_attributes[] = {
	&sensor_dev_attr_temp1_input.dev_attr.attr,
	&sensor_dev_attr_temp2_input.dev_attr.attr,
	&sensor_dev_attr_temp3_input.dev_attr.attr,
	&sensor_dev_attr_temp2_type.dev_attr.attr,
	&sensor_dev_attr_temp3_type.dev_attr.attr,
	&sensor_dev_attr_temp2_min.dev_attr.attr,
	&sensor_dev_attr_temp3_min.dev_attr.attr,
	&sensor_dev_attr_temp2_max.dev_attr.attr,
	&sensor_dev_attr_temp3_max.dev_attr.attr,
	&dev_attr_update_interval.attr,
	NULL
};

static const struct attribute_group lm95241_group = {
	.attrs = lm95241_attributes,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm95241_detect(struct i2c_client *new_client,
			  struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = new_client->adapter;
	int address = new_client->addr;
	const char *name;

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

	if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
	     == MANUFACTURER_ID)
	    && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
		>= DEFAULT_REVISION)) {
		name = DEVNAME;
	} else {
		dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n",
			address);
		return -ENODEV;
	}

	/* Fill the i2c board info */
	strlcpy(info->type, name, I2C_NAME_SIZE);
	return 0;
}

static void lm95241_init_client(struct i2c_client *client)
{
	struct lm95241_data *data = i2c_get_clientdata(client);

	data->interval = HZ;	/* 1 sec default */
	data->valid = 0;
	data->config = CFG_CR0076;
	data->model = 0;
	data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);

	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
				  R1FE_MASK | R2FE_MASK);
	i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
				  data->trutherm);
	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
				  data->model);
}

static int lm95241_probe(struct i2c_client *new_client,
			 const struct i2c_device_id *id)
{
	struct lm95241_data *data;
	int err;

	data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
	if (!data) {
		err = -ENOMEM;
		goto exit;
	}

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

	/* Initialize the LM95241 chip */
	lm95241_init_client(new_client);

	/* Register sysfs hooks */
	err = sysfs_create_group(&new_client->dev.kobj, &lm95241_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, &lm95241_group);
exit_free:
	kfree(data);
exit:
	return err;
}

static int lm95241_remove(struct i2c_client *client)
{
	struct lm95241_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &lm95241_group);

	kfree(data);
	return 0;
}

/* Driver data (common to all clients) */
static const struct i2c_device_id lm95241_id[] = {
	{ DEVNAME, 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm95241_id);

static struct i2c_driver lm95241_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= DEVNAME,
	},
	.probe		= lm95241_probe,
	.remove		= lm95241_remove,
	.id_table	= lm95241_id,
	.detect		= lm95241_detect,
	.address_list	= normal_i2c,
};

static int __init sensors_lm95241_init(void)
{
	return i2c_add_driver(&lm95241_driver);
}

static void __exit sensors_lm95241_exit(void)
{
	i2c_del_driver(&lm95241_driver);
}

MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
MODULE_DESCRIPTION("LM95241 sensor driver");
MODULE_LICENSE("GPL");

module_init(sensors_lm95241_init);
module_exit(sensors_lm95241_exit);