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