xref: /openbmc/linux/drivers/hwmon/lm95245.c (revision eb3fcf00) 
1 /*
2  * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com>
3  *
4  * The LM95245 is a sensor chip made by TI / National Semiconductor.
5  * It reports up to two temperatures (its own plus an external one).
6  *
7  * This driver is based on lm95241.c
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22  */
23 
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/i2c.h>
29 #include <linux/hwmon.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 #include <linux/sysfs.h>
34 
35 static const unsigned short normal_i2c[] = {
36 	0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END };
37 
38 /* LM95245 registers */
39 /* general registers */
40 #define LM95245_REG_RW_CONFIG1		0x03
41 #define LM95245_REG_RW_CONVERS_RATE	0x04
42 #define LM95245_REG_W_ONE_SHOT		0x0F
43 
44 /* diode configuration */
45 #define LM95245_REG_RW_CONFIG2		0xBF
46 #define LM95245_REG_RW_REMOTE_OFFH	0x11
47 #define LM95245_REG_RW_REMOTE_OFFL	0x12
48 
49 /* status registers */
50 #define LM95245_REG_R_STATUS1		0x02
51 #define LM95245_REG_R_STATUS2		0x33
52 
53 /* limit registers */
54 #define LM95245_REG_RW_REMOTE_OS_LIMIT		0x07
55 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT	0x20
56 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT	0x19
57 #define LM95245_REG_RW_COMMON_HYSTERESIS	0x21
58 
59 /* temperature signed */
60 #define LM95245_REG_R_LOCAL_TEMPH_S	0x00
61 #define LM95245_REG_R_LOCAL_TEMPL_S	0x30
62 #define LM95245_REG_R_REMOTE_TEMPH_S	0x01
63 #define LM95245_REG_R_REMOTE_TEMPL_S	0x10
64 /* temperature unsigned */
65 #define LM95245_REG_R_REMOTE_TEMPH_U	0x31
66 #define LM95245_REG_R_REMOTE_TEMPL_U	0x32
67 
68 /* id registers */
69 #define LM95245_REG_R_MAN_ID		0xFE
70 #define LM95245_REG_R_CHIP_ID		0xFF
71 
72 /* LM95245 specific bitfields */
73 #define CFG_STOP		0x40
74 #define CFG_REMOTE_TCRIT_MASK	0x10
75 #define CFG_REMOTE_OS_MASK	0x08
76 #define CFG_LOCAL_TCRIT_MASK	0x04
77 #define CFG_LOCAL_OS_MASK	0x02
78 
79 #define CFG2_OS_A0		0x40
80 #define CFG2_DIODE_FAULT_OS	0x20
81 #define CFG2_DIODE_FAULT_TCRIT	0x10
82 #define CFG2_REMOTE_TT		0x08
83 #define CFG2_REMOTE_FILTER_DIS	0x00
84 #define CFG2_REMOTE_FILTER_EN	0x06
85 
86 /* conversation rate in ms */
87 #define RATE_CR0063	0x00
88 #define RATE_CR0364	0x01
89 #define RATE_CR1000	0x02
90 #define RATE_CR2500	0x03
91 
92 #define STATUS1_DIODE_FAULT	0x04
93 #define STATUS1_RTCRIT		0x02
94 #define STATUS1_LOC		0x01
95 
96 #define MANUFACTURER_ID		0x01
97 #define LM95235_REVISION	0xB1
98 #define LM95245_REVISION	0xB3
99 
100 static const u8 lm95245_reg_address[] = {
101 	LM95245_REG_R_LOCAL_TEMPH_S,
102 	LM95245_REG_R_LOCAL_TEMPL_S,
103 	LM95245_REG_R_REMOTE_TEMPH_S,
104 	LM95245_REG_R_REMOTE_TEMPL_S,
105 	LM95245_REG_R_REMOTE_TEMPH_U,
106 	LM95245_REG_R_REMOTE_TEMPL_U,
107 	LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
108 	LM95245_REG_RW_REMOTE_TCRIT_LIMIT,
109 	LM95245_REG_RW_COMMON_HYSTERESIS,
110 	LM95245_REG_R_STATUS1,
111 };
112 
113 /* Client data (each client gets its own) */
114 struct lm95245_data {
115 	struct i2c_client *client;
116 	struct mutex update_lock;
117 	unsigned long last_updated;	/* in jiffies */
118 	unsigned long interval;	/* in msecs */
119 	bool valid;		/* zero until following fields are valid */
120 	/* registers values */
121 	u8 regs[ARRAY_SIZE(lm95245_reg_address)];
122 	u8 config1, config2;
123 };
124 
125 /* Conversions */
126 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
127 {
128 	return val_h * 1000 + val_l * 1000 / 256;
129 }
130 
131 static int temp_from_reg_signed(u8 val_h, u8 val_l)
132 {
133 	if (val_h & 0x80)
134 		return (val_h - 0x100) * 1000;
135 	return temp_from_reg_unsigned(val_h, val_l);
136 }
137 
138 static struct lm95245_data *lm95245_update_device(struct device *dev)
139 {
140 	struct lm95245_data *data = dev_get_drvdata(dev);
141 	struct i2c_client *client = data->client;
142 
143 	mutex_lock(&data->update_lock);
144 
145 	if (time_after(jiffies, data->last_updated
146 		+ msecs_to_jiffies(data->interval)) || !data->valid) {
147 		int i;
148 
149 		for (i = 0; i < ARRAY_SIZE(lm95245_reg_address); i++)
150 			data->regs[i]
151 			  = i2c_smbus_read_byte_data(client,
152 						     lm95245_reg_address[i]);
153 		data->last_updated = jiffies;
154 		data->valid = 1;
155 	}
156 
157 	mutex_unlock(&data->update_lock);
158 
159 	return data;
160 }
161 
162 static unsigned long lm95245_read_conversion_rate(struct i2c_client *client)
163 {
164 	int rate;
165 	unsigned long interval;
166 
167 	rate = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONVERS_RATE);
168 
169 	switch (rate) {
170 	case RATE_CR0063:
171 		interval = 63;
172 		break;
173 	case RATE_CR0364:
174 		interval = 364;
175 		break;
176 	case RATE_CR1000:
177 		interval = 1000;
178 		break;
179 	case RATE_CR2500:
180 	default:
181 		interval = 2500;
182 		break;
183 	}
184 
185 	return interval;
186 }
187 
188 static unsigned long lm95245_set_conversion_rate(struct i2c_client *client,
189 			unsigned long interval)
190 {
191 	int rate;
192 
193 	if (interval <= 63) {
194 		interval = 63;
195 		rate = RATE_CR0063;
196 	} else if (interval <= 364) {
197 		interval = 364;
198 		rate = RATE_CR0364;
199 	} else if (interval <= 1000) {
200 		interval = 1000;
201 		rate = RATE_CR1000;
202 	} else {
203 		interval = 2500;
204 		rate = RATE_CR2500;
205 	}
206 
207 	i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONVERS_RATE, rate);
208 
209 	return interval;
210 }
211 
212 /* Sysfs stuff */
213 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
214 			  char *buf)
215 {
216 	struct lm95245_data *data = lm95245_update_device(dev);
217 	int temp;
218 	int index = to_sensor_dev_attr(attr)->index;
219 
220 	/*
221 	 * Index 0 (Local temp) is always signed
222 	 * Index 2 (Remote temp) has both signed and unsigned data
223 	 * use signed calculation for remote if signed bit is set
224 	 */
225 	if (index == 0 || data->regs[index] & 0x80)
226 		temp = temp_from_reg_signed(data->regs[index],
227 			    data->regs[index + 1]);
228 	else
229 		temp = temp_from_reg_unsigned(data->regs[index + 2],
230 			    data->regs[index + 3]);
231 
232 	return snprintf(buf, PAGE_SIZE - 1, "%d\n", temp);
233 }
234 
235 static ssize_t show_limit(struct device *dev, struct device_attribute *attr,
236 			 char *buf)
237 {
238 	struct lm95245_data *data = lm95245_update_device(dev);
239 	int index = to_sensor_dev_attr(attr)->index;
240 
241 	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
242 			data->regs[index] * 1000);
243 }
244 
245 static ssize_t set_limit(struct device *dev, struct device_attribute *attr,
246 			const char *buf, size_t count)
247 {
248 	struct lm95245_data *data = dev_get_drvdata(dev);
249 	int index = to_sensor_dev_attr(attr)->index;
250 	struct i2c_client *client = data->client;
251 	unsigned long val;
252 
253 	if (kstrtoul(buf, 10, &val) < 0)
254 		return -EINVAL;
255 
256 	val /= 1000;
257 
258 	val = clamp_val(val, 0, (index == 6 ? 127 : 255));
259 
260 	mutex_lock(&data->update_lock);
261 
262 	data->valid = 0;
263 
264 	i2c_smbus_write_byte_data(client, lm95245_reg_address[index], val);
265 
266 	mutex_unlock(&data->update_lock);
267 
268 	return count;
269 }
270 
271 static ssize_t show_crit_hyst(struct device *dev, struct device_attribute *attr,
272 			char *buf)
273 {
274 	struct lm95245_data *data = lm95245_update_device(dev);
275 	int index = to_sensor_dev_attr(attr)->index;
276 	int hyst = data->regs[index] - data->regs[8];
277 
278 	return snprintf(buf, PAGE_SIZE - 1, "%d\n", hyst * 1000);
279 }
280 
281 static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr,
282 			const char *buf, size_t count)
283 {
284 	struct lm95245_data *data = dev_get_drvdata(dev);
285 	int index = to_sensor_dev_attr(attr)->index;
286 	struct i2c_client *client = data->client;
287 	unsigned long val;
288 	int hyst, limit;
289 
290 	if (kstrtoul(buf, 10, &val) < 0)
291 		return -EINVAL;
292 
293 	mutex_lock(&data->update_lock);
294 
295 	limit = i2c_smbus_read_byte_data(client, lm95245_reg_address[index]);
296 	hyst = limit - val / 1000;
297 	hyst = clamp_val(hyst, 0, 31);
298 	data->regs[8] = hyst;
299 
300 	/* shared crit hysteresis */
301 	i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS,
302 		hyst);
303 
304 	mutex_unlock(&data->update_lock);
305 
306 	return count;
307 }
308 
309 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
310 			 char *buf)
311 {
312 	struct lm95245_data *data = dev_get_drvdata(dev);
313 
314 	return snprintf(buf, PAGE_SIZE - 1,
315 		data->config2 & CFG2_REMOTE_TT ? "1\n" : "2\n");
316 }
317 
318 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
319 			const char *buf, size_t count)
320 {
321 	struct lm95245_data *data = dev_get_drvdata(dev);
322 	struct i2c_client *client = data->client;
323 	unsigned long val;
324 
325 	if (kstrtoul(buf, 10, &val) < 0)
326 		return -EINVAL;
327 	if (val != 1 && val != 2)
328 		return -EINVAL;
329 
330 	mutex_lock(&data->update_lock);
331 
332 	if (val == 1)
333 		data->config2 |= CFG2_REMOTE_TT;
334 	else
335 		data->config2 &= ~CFG2_REMOTE_TT;
336 
337 	data->valid = 0;
338 
339 	i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2,
340 				  data->config2);
341 
342 	mutex_unlock(&data->update_lock);
343 
344 	return count;
345 }
346 
347 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
348 			 char *buf)
349 {
350 	struct lm95245_data *data = lm95245_update_device(dev);
351 	int index = to_sensor_dev_attr(attr)->index;
352 
353 	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
354 			!!(data->regs[9] & index));
355 }
356 
357 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
358 			     char *buf)
359 {
360 	struct lm95245_data *data = lm95245_update_device(dev);
361 
362 	return snprintf(buf, PAGE_SIZE - 1, "%lu\n", data->interval);
363 }
364 
365 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
366 			    const char *buf, size_t count)
367 {
368 	struct lm95245_data *data = dev_get_drvdata(dev);
369 	struct i2c_client *client = data->client;
370 	unsigned long val;
371 
372 	if (kstrtoul(buf, 10, &val) < 0)
373 		return -EINVAL;
374 
375 	mutex_lock(&data->update_lock);
376 
377 	data->interval = lm95245_set_conversion_rate(client, val);
378 
379 	mutex_unlock(&data->update_lock);
380 
381 	return count;
382 }
383 
384 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
385 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit,
386 		set_limit, 6);
387 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_crit_hyst,
388 		set_crit_hyst, 6);
389 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
390 		STATUS1_LOC);
391 
392 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
393 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit,
394 		set_limit, 7);
395 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_crit_hyst, NULL, 7);
396 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
397 		STATUS1_RTCRIT);
398 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type,
399 		set_type, 0);
400 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL,
401 		STATUS1_DIODE_FAULT);
402 
403 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
404 		set_interval);
405 
406 static struct attribute *lm95245_attrs[] = {
407 	&sensor_dev_attr_temp1_input.dev_attr.attr,
408 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
409 	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
410 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
411 	&sensor_dev_attr_temp2_input.dev_attr.attr,
412 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
413 	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
414 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
415 	&sensor_dev_attr_temp2_type.dev_attr.attr,
416 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
417 	&dev_attr_update_interval.attr,
418 	NULL
419 };
420 ATTRIBUTE_GROUPS(lm95245);
421 
422 /* Return 0 if detection is successful, -ENODEV otherwise */
423 static int lm95245_detect(struct i2c_client *new_client,
424 			  struct i2c_board_info *info)
425 {
426 	struct i2c_adapter *adapter = new_client->adapter;
427 	int address = new_client->addr;
428 	const char *name;
429 	int rev, id;
430 
431 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
432 		return -ENODEV;
433 
434 	id = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID);
435 	if (id != MANUFACTURER_ID)
436 		return -ENODEV;
437 
438 	rev = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID);
439 	switch (rev) {
440 	case LM95235_REVISION:
441 		if (address != 0x18 && address != 0x29 && address != 0x4c)
442 			return -ENODEV;
443 		name = "lm95235";
444 		break;
445 	case LM95245_REVISION:
446 		name = "lm95245";
447 		break;
448 	default:
449 		return -ENODEV;
450 	}
451 
452 	strlcpy(info->type, name, I2C_NAME_SIZE);
453 	return 0;
454 }
455 
456 static void lm95245_init_client(struct i2c_client *client,
457 				struct lm95245_data *data)
458 {
459 	data->interval = lm95245_read_conversion_rate(client);
460 
461 	data->config1 = i2c_smbus_read_byte_data(client,
462 		LM95245_REG_RW_CONFIG1);
463 	data->config2 = i2c_smbus_read_byte_data(client,
464 		LM95245_REG_RW_CONFIG2);
465 
466 	if (data->config1 & CFG_STOP) {
467 		/* Clear the standby bit */
468 		data->config1 &= ~CFG_STOP;
469 		i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1,
470 			data->config1);
471 	}
472 }
473 
474 static int lm95245_probe(struct i2c_client *client,
475 			 const struct i2c_device_id *id)
476 {
477 	struct device *dev = &client->dev;
478 	struct lm95245_data *data;
479 	struct device *hwmon_dev;
480 
481 	data = devm_kzalloc(dev, sizeof(struct lm95245_data), GFP_KERNEL);
482 	if (!data)
483 		return -ENOMEM;
484 
485 	data->client = client;
486 	mutex_init(&data->update_lock);
487 
488 	/* Initialize the LM95245 chip */
489 	lm95245_init_client(client, data);
490 
491 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
492 							   data,
493 							   lm95245_groups);
494 	return PTR_ERR_OR_ZERO(hwmon_dev);
495 }
496 
497 /* Driver data (common to all clients) */
498 static const struct i2c_device_id lm95245_id[] = {
499 	{ "lm95235", 0 },
500 	{ "lm95245", 0 },
501 	{ }
502 };
503 MODULE_DEVICE_TABLE(i2c, lm95245_id);
504 
505 static struct i2c_driver lm95245_driver = {
506 	.class		= I2C_CLASS_HWMON,
507 	.driver = {
508 		.name	= "lm95245",
509 	},
510 	.probe		= lm95245_probe,
511 	.id_table	= lm95245_id,
512 	.detect		= lm95245_detect,
513 	.address_list	= normal_i2c,
514 };
515 
516 module_i2c_driver(lm95245_driver);
517 
518 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
519 MODULE_DESCRIPTION("LM95235/LM95245 sensor driver");
520 MODULE_LICENSE("GPL");
521