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1da177e4 LT |
1 | /* |
2 | * lm92 - Hardware monitoring driver | |
910e8dcf | 3 | * Copyright (C) 2005-2008 Jean Delvare <khali@linux-fr.org> |
1da177e4 LT |
4 | * |
5 | * Based on the lm90 driver, with some ideas taken from the lm_sensors | |
6 | * lm92 driver as well. | |
7 | * | |
8 | * The LM92 is a sensor chip made by National Semiconductor. It reports | |
9 | * its own temperature with a 0.0625 deg resolution and a 0.33 deg | |
10 | * accuracy. Complete datasheet can be obtained from National's website | |
11 | * at: | |
12 | * http://www.national.com/pf/LM/LM92.html | |
13 | * | |
14 | * This driver also supports the MAX6635 sensor chip made by Maxim. | |
15 | * This chip is compatible with the LM92, but has a lesser accuracy | |
16 | * (1.0 deg). Complete datasheet can be obtained from Maxim's website | |
17 | * at: | |
18 | * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074 | |
19 | * | |
20 | * Since the LM92 was the first chipset supported by this driver, most | |
21 | * comments will refer to this chipset, but are actually general and | |
22 | * concern all supported chipsets, unless mentioned otherwise. | |
23 | * | |
24 | * Support could easily be added for the National Semiconductor LM76 | |
25 | * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible | |
26 | * with the LM92. | |
27 | * | |
28 | * This program is free software; you can redistribute it and/or modify | |
29 | * it under the terms of the GNU General Public License as published by | |
30 | * the Free Software Foundation; either version 2 of the License, or | |
31 | * (at your option) any later version. | |
32 | * | |
33 | * This program is distributed in the hope that it will be useful, | |
34 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
35 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
36 | * GNU General Public License for more details. | |
37 | * | |
38 | * You should have received a copy of the GNU General Public License | |
39 | * along with this program; if not, write to the Free Software | |
40 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
41 | */ | |
42 | ||
43 | #include <linux/module.h> | |
44 | #include <linux/init.h> | |
45 | #include <linux/slab.h> | |
46 | #include <linux/i2c.h> | |
943b0830 | 47 | #include <linux/hwmon.h> |
6cb59e91 | 48 | #include <linux/hwmon-sysfs.h> |
943b0830 | 49 | #include <linux/err.h> |
9a61bf63 | 50 | #include <linux/mutex.h> |
1da177e4 LT |
51 | |
52 | /* The LM92 and MAX6635 have 2 two-state pins for address selection, | |
53 | resulting in 4 possible addresses. */ | |
25e9c86d MH |
54 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
55 | I2C_CLIENT_END }; | |
1da177e4 | 56 | |
1da177e4 LT |
57 | /* The LM92 registers */ |
58 | #define LM92_REG_CONFIG 0x01 /* 8-bit, RW */ | |
59 | #define LM92_REG_TEMP 0x00 /* 16-bit, RO */ | |
60 | #define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */ | |
61 | #define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */ | |
62 | #define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */ | |
63 | #define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */ | |
64 | #define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */ | |
65 | ||
66 | /* The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius, | |
67 | left-justified in 16-bit registers. No rounding is done, with such | |
68 | a resolution it's just not worth it. Note that the MAX6635 doesn't | |
69 | make use of the 4 lower bits for limits (i.e. effective resolution | |
70 | for limits is 1 degree Celsius). */ | |
71 | static inline int TEMP_FROM_REG(s16 reg) | |
72 | { | |
73 | return reg / 8 * 625 / 10; | |
74 | } | |
75 | ||
76 | static inline s16 TEMP_TO_REG(int val) | |
77 | { | |
78 | if (val <= -60000) | |
79 | return -60000 * 10 / 625 * 8; | |
80 | if (val >= 160000) | |
81 | return 160000 * 10 / 625 * 8; | |
82 | return val * 10 / 625 * 8; | |
83 | } | |
84 | ||
85 | /* Alarm flags are stored in the 3 LSB of the temperature register */ | |
86 | static inline u8 ALARMS_FROM_REG(s16 reg) | |
87 | { | |
88 | return reg & 0x0007; | |
89 | } | |
90 | ||
91 | /* Driver data (common to all clients) */ | |
92 | static struct i2c_driver lm92_driver; | |
93 | ||
94 | /* Client data (each client gets its own) */ | |
95 | struct lm92_data { | |
1beeffe4 | 96 | struct device *hwmon_dev; |
9a61bf63 | 97 | struct mutex update_lock; |
1da177e4 LT |
98 | char valid; /* zero until following fields are valid */ |
99 | unsigned long last_updated; /* in jiffies */ | |
100 | ||
101 | /* registers values */ | |
102 | s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst; | |
103 | }; | |
104 | ||
105 | ||
106 | /* | |
107 | * Sysfs attributes and callback functions | |
108 | */ | |
109 | ||
110 | static struct lm92_data *lm92_update_device(struct device *dev) | |
111 | { | |
112 | struct i2c_client *client = to_i2c_client(dev); | |
113 | struct lm92_data *data = i2c_get_clientdata(client); | |
114 | ||
9a61bf63 | 115 | mutex_lock(&data->update_lock); |
1da177e4 LT |
116 | |
117 | if (time_after(jiffies, data->last_updated + HZ) | |
118 | || !data->valid) { | |
119 | dev_dbg(&client->dev, "Updating lm92 data\n"); | |
90f4102c JD |
120 | data->temp1_input = i2c_smbus_read_word_swapped(client, |
121 | LM92_REG_TEMP); | |
122 | data->temp1_hyst = i2c_smbus_read_word_swapped(client, | |
123 | LM92_REG_TEMP_HYST); | |
124 | data->temp1_crit = i2c_smbus_read_word_swapped(client, | |
125 | LM92_REG_TEMP_CRIT); | |
126 | data->temp1_min = i2c_smbus_read_word_swapped(client, | |
127 | LM92_REG_TEMP_LOW); | |
128 | data->temp1_max = i2c_smbus_read_word_swapped(client, | |
129 | LM92_REG_TEMP_HIGH); | |
1da177e4 LT |
130 | |
131 | data->last_updated = jiffies; | |
132 | data->valid = 1; | |
133 | } | |
134 | ||
9a61bf63 | 135 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
136 | |
137 | return data; | |
138 | } | |
139 | ||
140 | #define show_temp(value) \ | |
8627f9ba | 141 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
142 | { \ |
143 | struct lm92_data *data = lm92_update_device(dev); \ | |
144 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \ | |
145 | } | |
146 | show_temp(temp1_input); | |
147 | show_temp(temp1_crit); | |
148 | show_temp(temp1_min); | |
149 | show_temp(temp1_max); | |
150 | ||
151 | #define set_temp(value, reg) \ | |
8627f9ba | 152 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \ |
1da177e4 LT |
153 | size_t count) \ |
154 | { \ | |
155 | struct i2c_client *client = to_i2c_client(dev); \ | |
156 | struct lm92_data *data = i2c_get_clientdata(client); \ | |
157 | long val = simple_strtol(buf, NULL, 10); \ | |
158 | \ | |
9a61bf63 | 159 | mutex_lock(&data->update_lock); \ |
1da177e4 | 160 | data->value = TEMP_TO_REG(val); \ |
90f4102c | 161 | i2c_smbus_write_word_swapped(client, reg, data->value); \ |
9a61bf63 | 162 | mutex_unlock(&data->update_lock); \ |
1da177e4 LT |
163 | return count; \ |
164 | } | |
165 | set_temp(temp1_crit, LM92_REG_TEMP_CRIT); | |
166 | set_temp(temp1_min, LM92_REG_TEMP_LOW); | |
167 | set_temp(temp1_max, LM92_REG_TEMP_HIGH); | |
168 | ||
8627f9ba | 169 | static ssize_t show_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
170 | { |
171 | struct lm92_data *data = lm92_update_device(dev); | |
172 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit) | |
173 | - TEMP_FROM_REG(data->temp1_hyst)); | |
174 | } | |
8627f9ba | 175 | static ssize_t show_temp1_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
176 | { |
177 | struct lm92_data *data = lm92_update_device(dev); | |
178 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max) | |
179 | - TEMP_FROM_REG(data->temp1_hyst)); | |
180 | } | |
8627f9ba | 181 | static ssize_t show_temp1_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
182 | { |
183 | struct lm92_data *data = lm92_update_device(dev); | |
184 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min) | |
185 | + TEMP_FROM_REG(data->temp1_hyst)); | |
186 | } | |
187 | ||
8627f9ba | 188 | static ssize_t set_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, |
1da177e4 LT |
189 | size_t count) |
190 | { | |
191 | struct i2c_client *client = to_i2c_client(dev); | |
192 | struct lm92_data *data = i2c_get_clientdata(client); | |
193 | long val = simple_strtol(buf, NULL, 10); | |
194 | ||
9a61bf63 | 195 | mutex_lock(&data->update_lock); |
1da177e4 | 196 | data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val; |
90f4102c JD |
197 | i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST, |
198 | TEMP_TO_REG(data->temp1_hyst)); | |
9a61bf63 | 199 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
200 | return count; |
201 | } | |
202 | ||
8627f9ba | 203 | static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
204 | { |
205 | struct lm92_data *data = lm92_update_device(dev); | |
206 | return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input)); | |
207 | } | |
208 | ||
6cb59e91 JD |
209 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
210 | char *buf) | |
211 | { | |
212 | int bitnr = to_sensor_dev_attr(attr)->index; | |
213 | struct lm92_data *data = lm92_update_device(dev); | |
214 | return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1); | |
215 | } | |
216 | ||
1da177e4 LT |
217 | static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL); |
218 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit, | |
219 | set_temp1_crit); | |
220 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst, | |
221 | set_temp1_crit_hyst); | |
222 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min, | |
223 | set_temp1_min); | |
224 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL); | |
225 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max, | |
226 | set_temp1_max); | |
227 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL); | |
228 | static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); | |
6cb59e91 JD |
229 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
230 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
231 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 LT |
232 | |
233 | ||
234 | /* | |
235 | * Detection and registration | |
236 | */ | |
237 | ||
238 | static void lm92_init_client(struct i2c_client *client) | |
239 | { | |
240 | u8 config; | |
241 | ||
242 | /* Start the conversions if needed */ | |
243 | config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); | |
244 | if (config & 0x01) | |
245 | i2c_smbus_write_byte_data(client, LM92_REG_CONFIG, | |
246 | config & 0xFE); | |
247 | } | |
248 | ||
249 | /* The MAX6635 has no identification register, so we have to use tricks | |
250 | to identify it reliably. This is somewhat slow. | |
251 | Note that we do NOT rely on the 2 MSB of the configuration register | |
252 | always reading 0, as suggested by the datasheet, because it was once | |
253 | reported not to be true. */ | |
254 | static int max6635_check(struct i2c_client *client) | |
255 | { | |
256 | u16 temp_low, temp_high, temp_hyst, temp_crit; | |
257 | u8 conf; | |
258 | int i; | |
259 | ||
260 | /* No manufacturer ID register, so a read from this address will | |
261 | always return the last read value. */ | |
262 | temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW); | |
263 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low) | |
264 | return 0; | |
265 | temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH); | |
266 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high) | |
267 | return 0; | |
268 | ||
269 | /* Limits are stored as integer values (signed, 9-bit). */ | |
270 | if ((temp_low & 0x7f00) || (temp_high & 0x7f00)) | |
271 | return 0; | |
272 | temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST); | |
273 | temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT); | |
274 | if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00)) | |
275 | return 0; | |
276 | ||
277 | /* Registers addresses were found to cycle over 16-byte boundaries. | |
278 | We don't test all registers with all offsets so as to save some | |
279 | reads and time, but this should still be sufficient to dismiss | |
280 | non-MAX6635 chips. */ | |
281 | conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); | |
282 | for (i=16; i<96; i*=2) { | |
283 | if (temp_hyst != i2c_smbus_read_word_data(client, | |
284 | LM92_REG_TEMP_HYST + i - 16) | |
285 | || temp_crit != i2c_smbus_read_word_data(client, | |
286 | LM92_REG_TEMP_CRIT + i) | |
287 | || temp_low != i2c_smbus_read_word_data(client, | |
288 | LM92_REG_TEMP_LOW + i + 16) | |
289 | || temp_high != i2c_smbus_read_word_data(client, | |
290 | LM92_REG_TEMP_HIGH + i + 32) | |
291 | || conf != i2c_smbus_read_byte_data(client, | |
292 | LM92_REG_CONFIG + i)) | |
293 | return 0; | |
294 | } | |
295 | ||
296 | return 1; | |
297 | } | |
298 | ||
0501a381 MH |
299 | static struct attribute *lm92_attributes[] = { |
300 | &dev_attr_temp1_input.attr, | |
301 | &dev_attr_temp1_crit.attr, | |
302 | &dev_attr_temp1_crit_hyst.attr, | |
303 | &dev_attr_temp1_min.attr, | |
304 | &dev_attr_temp1_min_hyst.attr, | |
305 | &dev_attr_temp1_max.attr, | |
306 | &dev_attr_temp1_max_hyst.attr, | |
307 | &dev_attr_alarms.attr, | |
6cb59e91 JD |
308 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
309 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
310 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
311 | NULL |
312 | }; | |
313 | ||
314 | static const struct attribute_group lm92_group = { | |
315 | .attrs = lm92_attributes, | |
316 | }; | |
317 | ||
910e8dcf | 318 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 319 | static int lm92_detect(struct i2c_client *new_client, |
910e8dcf | 320 | struct i2c_board_info *info) |
1da177e4 | 321 | { |
910e8dcf | 322 | struct i2c_adapter *adapter = new_client->adapter; |
52df6440 JD |
323 | u8 config; |
324 | u16 man_id; | |
1da177e4 LT |
325 | |
326 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
327 | | I2C_FUNC_SMBUS_WORD_DATA)) | |
910e8dcf | 328 | return -ENODEV; |
1da177e4 | 329 | |
52df6440 JD |
330 | config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG); |
331 | man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID); | |
332 | ||
333 | if ((config & 0xe0) == 0x00 && man_id == 0x0180) | |
334 | pr_info("lm92: Found National Semiconductor LM92 chip\n"); | |
335 | else if (max6635_check(new_client)) | |
336 | pr_info("lm92: Found Maxim MAX6635 chip\n"); | |
337 | else | |
338 | return -ENODEV; | |
1da177e4 | 339 | |
910e8dcf JD |
340 | strlcpy(info->type, "lm92", I2C_NAME_SIZE); |
341 | ||
342 | return 0; | |
343 | } | |
344 | ||
345 | static int lm92_probe(struct i2c_client *new_client, | |
346 | const struct i2c_device_id *id) | |
347 | { | |
348 | struct lm92_data *data; | |
349 | int err; | |
350 | ||
351 | data = kzalloc(sizeof(struct lm92_data), GFP_KERNEL); | |
352 | if (!data) { | |
353 | err = -ENOMEM; | |
354 | goto exit; | |
355 | } | |
356 | ||
357 | i2c_set_clientdata(new_client, data); | |
1da177e4 | 358 | data->valid = 0; |
9a61bf63 | 359 | mutex_init(&data->update_lock); |
1da177e4 | 360 | |
1da177e4 LT |
361 | /* Initialize the chipset */ |
362 | lm92_init_client(new_client); | |
363 | ||
364 | /* Register sysfs hooks */ | |
0501a381 | 365 | if ((err = sysfs_create_group(&new_client->dev.kobj, &lm92_group))) |
910e8dcf | 366 | goto exit_free; |
0501a381 | 367 | |
1beeffe4 TJ |
368 | data->hwmon_dev = hwmon_device_register(&new_client->dev); |
369 | if (IS_ERR(data->hwmon_dev)) { | |
370 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 371 | goto exit_remove; |
943b0830 MH |
372 | } |
373 | ||
1da177e4 LT |
374 | return 0; |
375 | ||
0501a381 MH |
376 | exit_remove: |
377 | sysfs_remove_group(&new_client->dev.kobj, &lm92_group); | |
1da177e4 LT |
378 | exit_free: |
379 | kfree(data); | |
380 | exit: | |
381 | return err; | |
382 | } | |
383 | ||
910e8dcf | 384 | static int lm92_remove(struct i2c_client *client) |
1da177e4 | 385 | { |
943b0830 | 386 | struct lm92_data *data = i2c_get_clientdata(client); |
1da177e4 | 387 | |
1beeffe4 | 388 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 389 | sysfs_remove_group(&client->dev.kobj, &lm92_group); |
943b0830 | 390 | |
943b0830 | 391 | kfree(data); |
1da177e4 LT |
392 | return 0; |
393 | } | |
394 | ||
395 | ||
396 | /* | |
397 | * Module and driver stuff | |
398 | */ | |
399 | ||
910e8dcf | 400 | static const struct i2c_device_id lm92_id[] = { |
1f86df49 | 401 | { "lm92", 0 }, |
910e8dcf JD |
402 | /* max6635 could be added here */ |
403 | { } | |
404 | }; | |
405 | MODULE_DEVICE_TABLE(i2c, lm92_id); | |
406 | ||
1da177e4 | 407 | static struct i2c_driver lm92_driver = { |
910e8dcf | 408 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 409 | .driver = { |
cdaf7934 LR |
410 | .name = "lm92", |
411 | }, | |
910e8dcf JD |
412 | .probe = lm92_probe, |
413 | .remove = lm92_remove, | |
414 | .id_table = lm92_id, | |
415 | .detect = lm92_detect, | |
c3813d6a | 416 | .address_list = normal_i2c, |
1da177e4 LT |
417 | }; |
418 | ||
f0967eea | 419 | module_i2c_driver(lm92_driver); |
1da177e4 LT |
420 | |
421 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); | |
422 | MODULE_DESCRIPTION("LM92/MAX6635 driver"); | |
423 | MODULE_LICENSE("GPL"); |