summaryrefslogtreecommitdiffstats
path: root/drivers/hwmon/lm83.c
blob: 12370dcefa6aba3cbbe963bc274ff6334fbb46f1 (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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
 *          monitoring
 * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>
 *
 * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
 * a sensor chip made by National Semiconductor. It reports up to four
 * temperatures (its own plus up to three external ones) with a 1 deg
 * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
 * from National's website at:
 *   http://www.national.com/pf/LM/LM83.html
 * Since the datasheet omits to give the chip stepping code, I give it
 * here: 0x03 (at register 0xff).
 *
 * Also supports the LM82 temp sensor, which is basically a stripped down
 * model of the LM83.  Datasheet is here:
 * http://www.national.com/pf/LM/LM82.html
 */

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

/*
 * Addresses to scan
 * Address is selected using 2 three-level pins, resulting in 9 possible
 * addresses.
 */

static const unsigned short normal_i2c[] = {
	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };

enum chips { lm83, lm82 };

/*
 * The LM83 registers
 * Manufacturer ID is 0x01 for National Semiconductor.
 */

#define LM83_REG_R_MAN_ID		0xFE
#define LM83_REG_R_CHIP_ID		0xFF
#define LM83_REG_R_CONFIG		0x03
#define LM83_REG_W_CONFIG		0x09
#define LM83_REG_R_STATUS1		0x02
#define LM83_REG_R_STATUS2		0x35
#define LM83_REG_R_LOCAL_TEMP		0x00
#define LM83_REG_R_LOCAL_HIGH		0x05
#define LM83_REG_W_LOCAL_HIGH		0x0B
#define LM83_REG_R_REMOTE1_TEMP		0x30
#define LM83_REG_R_REMOTE1_HIGH		0x38
#define LM83_REG_W_REMOTE1_HIGH		0x50
#define LM83_REG_R_REMOTE2_TEMP		0x01
#define LM83_REG_R_REMOTE2_HIGH		0x07
#define LM83_REG_W_REMOTE2_HIGH		0x0D
#define LM83_REG_R_REMOTE3_TEMP		0x31
#define LM83_REG_R_REMOTE3_HIGH		0x3A
#define LM83_REG_W_REMOTE3_HIGH		0x52
#define LM83_REG_R_TCRIT		0x42
#define LM83_REG_W_TCRIT		0x5A

static const u8 LM83_REG_TEMP[] = {
	LM83_REG_R_LOCAL_TEMP,
	LM83_REG_R_REMOTE1_TEMP,
	LM83_REG_R_REMOTE2_TEMP,
	LM83_REG_R_REMOTE3_TEMP,
};

static const u8 LM83_REG_MAX[] = {
	LM83_REG_R_LOCAL_HIGH,
	LM83_REG_R_REMOTE1_HIGH,
	LM83_REG_R_REMOTE2_HIGH,
	LM83_REG_R_REMOTE3_HIGH,
};

/* alarm and fault registers and bits, indexed by channel */
static const u8 LM83_ALARM_REG[] = {
	LM83_REG_R_STATUS1, LM83_REG_R_STATUS2, LM83_REG_R_STATUS1, LM83_REG_R_STATUS2
};

static const u8 LM83_MAX_ALARM_BIT[] = {
	BIT(6), BIT(7), BIT(4), BIT(4)
};

static const u8 LM83_CRIT_ALARM_BIT[] = {
	BIT(0), BIT(0), BIT(1), BIT(1)
};

static const u8 LM83_FAULT_BIT[] = {
	0, BIT(5), BIT(2), BIT(2)
};

/*
 * Client data (each client gets its own)
 */

struct lm83_data {
	struct regmap *regmap;
	enum chips type;
};

/* regmap code */

static int lm83_regmap_reg_read(void *context, unsigned int reg, unsigned int *val)
{
	struct i2c_client *client = context;
	int ret;

	ret = i2c_smbus_read_byte_data(client, reg);
	if (ret < 0)
		return ret;

	*val = ret;
	return 0;
}

/*
 * The regmap write function maps read register addresses to write register
 * addresses. This is necessary for regmap register caching to work.
 * An alternative would be to clear the regmap cache whenever a register is
 * written, but that would be much more expensive.
 */
static int lm83_regmap_reg_write(void *context, unsigned int reg, unsigned int val)
{
	struct i2c_client *client = context;

	switch (reg) {
	case LM83_REG_R_CONFIG:
	case LM83_REG_R_LOCAL_HIGH:
	case LM83_REG_R_REMOTE2_HIGH:
		reg += 0x06;
		break;
	case LM83_REG_R_REMOTE1_HIGH:
	case LM83_REG_R_REMOTE3_HIGH:
	case LM83_REG_R_TCRIT:
		reg += 0x18;
		break;
	default:
		break;
	}

	return i2c_smbus_write_byte_data(client, reg, val);
}

static bool lm83_regmap_is_volatile(struct device *dev, unsigned int reg)
{
	switch (reg) {
	case LM83_REG_R_LOCAL_TEMP:
	case LM83_REG_R_REMOTE1_TEMP:
	case LM83_REG_R_REMOTE2_TEMP:
	case LM83_REG_R_REMOTE3_TEMP:
	case LM83_REG_R_STATUS1:
	case LM83_REG_R_STATUS2:
		return true;
	default:
		return false;
	}
}

static const struct regmap_config lm83_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.cache_type = REGCACHE_RBTREE,
	.volatile_reg = lm83_regmap_is_volatile,
	.reg_read = lm83_regmap_reg_read,
	.reg_write = lm83_regmap_reg_write,
};

/* hwmon API */

static int lm83_temp_read(struct device *dev, u32 attr, int channel, long *val)
{
	struct lm83_data *data = dev_get_drvdata(dev);
	unsigned int regval;
	int err;

	switch (attr) {
	case hwmon_temp_input:
		err = regmap_read(data->regmap, LM83_REG_TEMP[channel], &regval);
		if (err < 0)
			return err;
		*val = (s8)regval * 1000;
		break;
	case hwmon_temp_max:
		err = regmap_read(data->regmap, LM83_REG_MAX[channel], &regval);
		if (err < 0)
			return err;
		*val = (s8)regval * 1000;
		break;
	case hwmon_temp_crit:
		err = regmap_read(data->regmap, LM83_REG_R_TCRIT, &regval);
		if (err < 0)
			return err;
		*val = (s8)regval * 1000;
		break;
	case hwmon_temp_max_alarm:
		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
		if (err < 0)
			return err;
		*val = !!(regval & LM83_MAX_ALARM_BIT[channel]);
		break;
	case hwmon_temp_crit_alarm:
		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
		if (err < 0)
			return err;
		*val = !!(regval & LM83_CRIT_ALARM_BIT[channel]);
		break;
	case hwmon_temp_fault:
		err = regmap_read(data->regmap, LM83_ALARM_REG[channel], &regval);
		if (err < 0)
			return err;
		*val = !!(regval & LM83_FAULT_BIT[channel]);
		break;
	default:
		return -EOPNOTSUPP;
	}
	return 0;
}

static int lm83_temp_write(struct device *dev, u32 attr, int channel, long val)
{
	struct lm83_data *data = dev_get_drvdata(dev);
	unsigned int regval;
	int err;

	regval = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);

	switch (attr) {
	case hwmon_temp_max:
		err = regmap_write(data->regmap, LM83_REG_MAX[channel], regval);
		if (err < 0)
			return err;
		break;
	case hwmon_temp_crit:
		err = regmap_write(data->regmap, LM83_REG_R_TCRIT, regval);
		if (err < 0)
			return err;
		break;
	default:
		return -EOPNOTSUPP;
	}
	return 0;
}

static int lm83_chip_read(struct device *dev, u32 attr, int channel, long *val)
{
	struct lm83_data *data = dev_get_drvdata(dev);
	unsigned int regval;
	int err;

	switch (attr) {
	case hwmon_chip_alarms:
		err = regmap_read(data->regmap, LM83_REG_R_STATUS1, &regval);
		if (err < 0)
			return err;
		*val = regval;
		err = regmap_read(data->regmap, LM83_REG_R_STATUS2, &regval);
		if (err < 0)
			return err;
		*val |= regval << 8;
		return 0;
	default:
		return -EOPNOTSUPP;
	}

	return 0;
}

static int lm83_read(struct device *dev, enum hwmon_sensor_types type,
		     u32 attr, int channel, long *val)
{
	switch (type) {
	case hwmon_chip:
		return lm83_chip_read(dev, attr, channel, val);
	case hwmon_temp:
		return lm83_temp_read(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static int lm83_write(struct device *dev, enum hwmon_sensor_types type,
		      u32 attr, int channel, long val)
{
	switch (type) {
	case hwmon_temp:
		return lm83_temp_write(dev, attr, channel, val);
	default:
		return -EOPNOTSUPP;
	}
}

static umode_t lm83_is_visible(const void *_data, enum hwmon_sensor_types type,
			       u32 attr, int channel)
{
	const struct lm83_data *data = _data;

	/*
	 * LM82 only supports a single external channel, modeled as channel 2.
	 */
	if (data->type == lm82 && (channel == 1 || channel == 3))
		return 0;

	switch (type) {
	case hwmon_chip:
		if (attr == hwmon_chip_alarms)
			return 0444;
		break;
	case hwmon_temp:
		switch (attr) {
		case hwmon_temp_input:
		case hwmon_temp_max_alarm:
		case hwmon_temp_crit_alarm:
			return 0444;
		case hwmon_temp_fault:
			if (channel)
				return 0444;
			break;
		case hwmon_temp_max:
			return 0644;
		case hwmon_temp_crit:
			if (channel == 2)
				return 0644;
			return 0444;
		default:
			break;
		}
		break;
	default:
		break;
	}
	return 0;
}

static const struct hwmon_channel_info *lm83_info[] = {
	HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
	HWMON_CHANNEL_INFO(temp,
			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
			   HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT
			   ),
	NULL
};

static const struct hwmon_ops lm83_hwmon_ops = {
	.is_visible = lm83_is_visible,
	.read = lm83_read,
	.write = lm83_write,
};

static const struct hwmon_chip_info lm83_chip_info = {
	.ops = &lm83_hwmon_ops,
	.info = lm83_info,
};

/* Return 0 if detection is successful, -ENODEV otherwise */
static int lm83_detect(struct i2c_client *client,
		       struct i2c_board_info *info)
{
	struct i2c_adapter *adapter = client->adapter;
	const char *name;
	u8 man_id, chip_id;

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

	/* Detection */
	if ((i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1) & 0xA8) ||
	    (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2) & 0x48) ||
	    (i2c_smbus_read_byte_data(client, LM83_REG_R_CONFIG) & 0x41)) {
		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
			client->addr);
		return -ENODEV;
	}

	/* Identification */
	man_id = i2c_smbus_read_byte_data(client, LM83_REG_R_MAN_ID);
	if (man_id != 0x01)	/* National Semiconductor */
		return -ENODEV;

	chip_id = i2c_smbus_read_byte_data(client, LM83_REG_R_CHIP_ID);
	switch (chip_id) {
	case 0x03:
		/*
		 * According to the LM82 datasheet dated March 2013, recent
		 * revisions of LM82 have a die revision of 0x03. This was
		 * confirmed with a real chip. Further details in this revision
		 * of the LM82 datasheet strongly suggest that LM82 is just a
		 * repackaged LM83. It is therefore impossible to distinguish
		 * those chips from LM83, and they will be misdetected as LM83.
		 */
		name = "lm83";
		break;
	case 0x01:
		name = "lm82";
		break;
	default:
		/* identification failed */
		dev_dbg(&adapter->dev,
			"Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
			man_id, chip_id);
		return -ENODEV;
	}

	strlcpy(info->type, name, I2C_NAME_SIZE);

	return 0;
}

static const struct i2c_device_id lm83_id[] = {
	{ "lm83", lm83 },
	{ "lm82", lm82 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, lm83_id);

static int lm83_probe(struct i2c_client *client)
{
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct lm83_data *data;

	data = devm_kzalloc(dev, sizeof(struct lm83_data), GFP_KERNEL);
	if (!data)
		return -ENOMEM;

	data->regmap = devm_regmap_init(dev, NULL, client, &lm83_regmap_config);
	if (IS_ERR(data->regmap))
		return PTR_ERR(data->regmap);

	data->type = i2c_match_id(lm83_id, client)->driver_data;

	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
							 data, &lm83_chip_info, NULL);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

/*
 * Driver data (common to all clients)
 */

static struct i2c_driver lm83_driver = {
	.class		= I2C_CLASS_HWMON,
	.driver = {
		.name	= "lm83",
	},
	.probe_new	= lm83_probe,
	.id_table	= lm83_id,
	.detect		= lm83_detect,
	.address_list	= normal_i2c,
};

module_i2c_driver(lm83_driver);

MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
MODULE_DESCRIPTION("LM83 driver");
MODULE_LICENSE("GPL");