Commit | Line | Data |
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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> |
dcd8f392 | 51 | #include <linux/jiffies.h> |
1da177e4 | 52 | |
a318afd8 GR |
53 | /* |
54 | * The LM92 and MAX6635 have 2 two-state pins for address selection, | |
55 | * resulting in 4 possible addresses. | |
56 | */ | |
25e9c86d MH |
57 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
58 | I2C_CLIENT_END }; | |
1da177e4 | 59 | |
1da177e4 LT |
60 | /* The LM92 registers */ |
61 | #define LM92_REG_CONFIG 0x01 /* 8-bit, RW */ | |
62 | #define LM92_REG_TEMP 0x00 /* 16-bit, RO */ | |
63 | #define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */ | |
64 | #define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */ | |
65 | #define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */ | |
66 | #define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */ | |
67 | #define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */ | |
68 | ||
a318afd8 GR |
69 | /* |
70 | * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius, | |
71 | * left-justified in 16-bit registers. No rounding is done, with such | |
72 | * a resolution it's just not worth it. Note that the MAX6635 doesn't | |
73 | * make use of the 4 lower bits for limits (i.e. effective resolution | |
74 | * for limits is 1 degree Celsius). | |
75 | */ | |
1da177e4 LT |
76 | static inline int TEMP_FROM_REG(s16 reg) |
77 | { | |
78 | return reg / 8 * 625 / 10; | |
79 | } | |
80 | ||
81 | static inline s16 TEMP_TO_REG(int val) | |
82 | { | |
83 | if (val <= -60000) | |
84 | return -60000 * 10 / 625 * 8; | |
85 | if (val >= 160000) | |
86 | return 160000 * 10 / 625 * 8; | |
87 | return val * 10 / 625 * 8; | |
88 | } | |
89 | ||
90 | /* Alarm flags are stored in the 3 LSB of the temperature register */ | |
91 | static inline u8 ALARMS_FROM_REG(s16 reg) | |
92 | { | |
93 | return reg & 0x0007; | |
94 | } | |
95 | ||
96 | /* Driver data (common to all clients) */ | |
97 | static struct i2c_driver lm92_driver; | |
98 | ||
99 | /* Client data (each client gets its own) */ | |
100 | struct lm92_data { | |
1beeffe4 | 101 | struct device *hwmon_dev; |
9a61bf63 | 102 | struct mutex update_lock; |
1da177e4 LT |
103 | char valid; /* zero until following fields are valid */ |
104 | unsigned long last_updated; /* in jiffies */ | |
105 | ||
106 | /* registers values */ | |
107 | s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst; | |
108 | }; | |
109 | ||
110 | ||
111 | /* | |
112 | * Sysfs attributes and callback functions | |
113 | */ | |
114 | ||
115 | static struct lm92_data *lm92_update_device(struct device *dev) | |
116 | { | |
117 | struct i2c_client *client = to_i2c_client(dev); | |
118 | struct lm92_data *data = i2c_get_clientdata(client); | |
119 | ||
9a61bf63 | 120 | mutex_lock(&data->update_lock); |
1da177e4 LT |
121 | |
122 | if (time_after(jiffies, data->last_updated + HZ) | |
123 | || !data->valid) { | |
124 | dev_dbg(&client->dev, "Updating lm92 data\n"); | |
90f4102c JD |
125 | data->temp1_input = i2c_smbus_read_word_swapped(client, |
126 | LM92_REG_TEMP); | |
127 | data->temp1_hyst = i2c_smbus_read_word_swapped(client, | |
128 | LM92_REG_TEMP_HYST); | |
129 | data->temp1_crit = i2c_smbus_read_word_swapped(client, | |
130 | LM92_REG_TEMP_CRIT); | |
131 | data->temp1_min = i2c_smbus_read_word_swapped(client, | |
132 | LM92_REG_TEMP_LOW); | |
133 | data->temp1_max = i2c_smbus_read_word_swapped(client, | |
134 | LM92_REG_TEMP_HIGH); | |
1da177e4 LT |
135 | |
136 | data->last_updated = jiffies; | |
137 | data->valid = 1; | |
138 | } | |
139 | ||
9a61bf63 | 140 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
141 | |
142 | return data; | |
143 | } | |
144 | ||
145 | #define show_temp(value) \ | |
a318afd8 GR |
146 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, \ |
147 | char *buf) \ | |
1da177e4 LT |
148 | { \ |
149 | struct lm92_data *data = lm92_update_device(dev); \ | |
150 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \ | |
151 | } | |
152 | show_temp(temp1_input); | |
153 | show_temp(temp1_crit); | |
154 | show_temp(temp1_min); | |
155 | show_temp(temp1_max); | |
156 | ||
157 | #define set_temp(value, reg) \ | |
a318afd8 GR |
158 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \ |
159 | const char *buf, \ | |
1da177e4 LT |
160 | size_t count) \ |
161 | { \ | |
162 | struct i2c_client *client = to_i2c_client(dev); \ | |
163 | struct lm92_data *data = i2c_get_clientdata(client); \ | |
a318afd8 GR |
164 | long val; \ |
165 | int err = kstrtol(buf, 10, &val); \ | |
166 | if (err) \ | |
167 | return err; \ | |
168 | \ | |
9a61bf63 | 169 | mutex_lock(&data->update_lock); \ |
1da177e4 | 170 | data->value = TEMP_TO_REG(val); \ |
90f4102c | 171 | i2c_smbus_write_word_swapped(client, reg, data->value); \ |
9a61bf63 | 172 | mutex_unlock(&data->update_lock); \ |
1da177e4 LT |
173 | return count; \ |
174 | } | |
175 | set_temp(temp1_crit, LM92_REG_TEMP_CRIT); | |
176 | set_temp(temp1_min, LM92_REG_TEMP_LOW); | |
177 | set_temp(temp1_max, LM92_REG_TEMP_HIGH); | |
178 | ||
a318afd8 GR |
179 | static ssize_t show_temp1_crit_hyst(struct device *dev, |
180 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
181 | { |
182 | struct lm92_data *data = lm92_update_device(dev); | |
183 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit) | |
184 | - TEMP_FROM_REG(data->temp1_hyst)); | |
185 | } | |
a318afd8 GR |
186 | static ssize_t show_temp1_max_hyst(struct device *dev, |
187 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
188 | { |
189 | struct lm92_data *data = lm92_update_device(dev); | |
190 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max) | |
191 | - TEMP_FROM_REG(data->temp1_hyst)); | |
192 | } | |
a318afd8 GR |
193 | static ssize_t show_temp1_min_hyst(struct device *dev, |
194 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
195 | { |
196 | struct lm92_data *data = lm92_update_device(dev); | |
197 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min) | |
198 | + TEMP_FROM_REG(data->temp1_hyst)); | |
199 | } | |
200 | ||
a318afd8 GR |
201 | static ssize_t set_temp1_crit_hyst(struct device *dev, |
202 | struct device_attribute *attr, | |
203 | const char *buf, size_t count) | |
1da177e4 LT |
204 | { |
205 | struct i2c_client *client = to_i2c_client(dev); | |
206 | struct lm92_data *data = i2c_get_clientdata(client); | |
a318afd8 GR |
207 | long val; |
208 | int err; | |
209 | ||
210 | err = kstrtol(buf, 10, &val); | |
211 | if (err) | |
212 | return err; | |
1da177e4 | 213 | |
9a61bf63 | 214 | mutex_lock(&data->update_lock); |
1da177e4 | 215 | data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val; |
90f4102c JD |
216 | i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST, |
217 | TEMP_TO_REG(data->temp1_hyst)); | |
9a61bf63 | 218 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
219 | return count; |
220 | } | |
221 | ||
a318afd8 GR |
222 | static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, |
223 | char *buf) | |
1da177e4 LT |
224 | { |
225 | struct lm92_data *data = lm92_update_device(dev); | |
226 | return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input)); | |
227 | } | |
228 | ||
6cb59e91 JD |
229 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
230 | char *buf) | |
231 | { | |
232 | int bitnr = to_sensor_dev_attr(attr)->index; | |
233 | struct lm92_data *data = lm92_update_device(dev); | |
234 | return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1); | |
235 | } | |
236 | ||
1da177e4 LT |
237 | static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL); |
238 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit, | |
239 | set_temp1_crit); | |
240 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst, | |
241 | set_temp1_crit_hyst); | |
242 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min, | |
243 | set_temp1_min); | |
244 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL); | |
245 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max, | |
246 | set_temp1_max); | |
247 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL); | |
248 | static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); | |
6cb59e91 JD |
249 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
250 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
251 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 LT |
252 | |
253 | ||
254 | /* | |
255 | * Detection and registration | |
256 | */ | |
257 | ||
258 | static void lm92_init_client(struct i2c_client *client) | |
259 | { | |
260 | u8 config; | |
261 | ||
262 | /* Start the conversions if needed */ | |
263 | config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); | |
264 | if (config & 0x01) | |
265 | i2c_smbus_write_byte_data(client, LM92_REG_CONFIG, | |
266 | config & 0xFE); | |
267 | } | |
268 | ||
a318afd8 GR |
269 | /* |
270 | * The MAX6635 has no identification register, so we have to use tricks | |
271 | * to identify it reliably. This is somewhat slow. | |
272 | * Note that we do NOT rely on the 2 MSB of the configuration register | |
273 | * always reading 0, as suggested by the datasheet, because it was once | |
274 | * reported not to be true. | |
275 | */ | |
1da177e4 LT |
276 | static int max6635_check(struct i2c_client *client) |
277 | { | |
278 | u16 temp_low, temp_high, temp_hyst, temp_crit; | |
279 | u8 conf; | |
280 | int i; | |
281 | ||
a318afd8 GR |
282 | /* |
283 | * No manufacturer ID register, so a read from this address will | |
284 | * always return the last read value. | |
285 | */ | |
1da177e4 LT |
286 | temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW); |
287 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low) | |
288 | return 0; | |
289 | temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH); | |
290 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high) | |
291 | return 0; | |
a318afd8 | 292 | |
1da177e4 LT |
293 | /* Limits are stored as integer values (signed, 9-bit). */ |
294 | if ((temp_low & 0x7f00) || (temp_high & 0x7f00)) | |
295 | return 0; | |
296 | temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST); | |
297 | temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT); | |
298 | if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00)) | |
299 | return 0; | |
300 | ||
a318afd8 GR |
301 | /* |
302 | * Registers addresses were found to cycle over 16-byte boundaries. | |
303 | * We don't test all registers with all offsets so as to save some | |
304 | * reads and time, but this should still be sufficient to dismiss | |
305 | * non-MAX6635 chips. | |
306 | */ | |
1da177e4 | 307 | conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); |
a318afd8 | 308 | for (i = 16; i < 96; i *= 2) { |
1da177e4 | 309 | if (temp_hyst != i2c_smbus_read_word_data(client, |
a318afd8 | 310 | LM92_REG_TEMP_HYST + i - 16) |
1da177e4 | 311 | || temp_crit != i2c_smbus_read_word_data(client, |
a318afd8 | 312 | LM92_REG_TEMP_CRIT + i) |
1da177e4 LT |
313 | || temp_low != i2c_smbus_read_word_data(client, |
314 | LM92_REG_TEMP_LOW + i + 16) | |
315 | || temp_high != i2c_smbus_read_word_data(client, | |
a318afd8 | 316 | LM92_REG_TEMP_HIGH + i + 32) |
1da177e4 | 317 | || conf != i2c_smbus_read_byte_data(client, |
a318afd8 | 318 | LM92_REG_CONFIG + i)) |
1da177e4 LT |
319 | return 0; |
320 | } | |
321 | ||
322 | return 1; | |
323 | } | |
324 | ||
0501a381 MH |
325 | static struct attribute *lm92_attributes[] = { |
326 | &dev_attr_temp1_input.attr, | |
327 | &dev_attr_temp1_crit.attr, | |
328 | &dev_attr_temp1_crit_hyst.attr, | |
329 | &dev_attr_temp1_min.attr, | |
330 | &dev_attr_temp1_min_hyst.attr, | |
331 | &dev_attr_temp1_max.attr, | |
332 | &dev_attr_temp1_max_hyst.attr, | |
333 | &dev_attr_alarms.attr, | |
6cb59e91 JD |
334 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
335 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
336 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
337 | NULL |
338 | }; | |
339 | ||
340 | static const struct attribute_group lm92_group = { | |
341 | .attrs = lm92_attributes, | |
342 | }; | |
343 | ||
910e8dcf | 344 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 345 | static int lm92_detect(struct i2c_client *new_client, |
910e8dcf | 346 | struct i2c_board_info *info) |
1da177e4 | 347 | { |
910e8dcf | 348 | struct i2c_adapter *adapter = new_client->adapter; |
52df6440 JD |
349 | u8 config; |
350 | u16 man_id; | |
1da177e4 LT |
351 | |
352 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
353 | | I2C_FUNC_SMBUS_WORD_DATA)) | |
910e8dcf | 354 | return -ENODEV; |
1da177e4 | 355 | |
52df6440 JD |
356 | config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG); |
357 | man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID); | |
358 | ||
359 | if ((config & 0xe0) == 0x00 && man_id == 0x0180) | |
360 | pr_info("lm92: Found National Semiconductor LM92 chip\n"); | |
361 | else if (max6635_check(new_client)) | |
362 | pr_info("lm92: Found Maxim MAX6635 chip\n"); | |
363 | else | |
364 | return -ENODEV; | |
1da177e4 | 365 | |
910e8dcf JD |
366 | strlcpy(info->type, "lm92", I2C_NAME_SIZE); |
367 | ||
368 | return 0; | |
369 | } | |
370 | ||
371 | static int lm92_probe(struct i2c_client *new_client, | |
372 | const struct i2c_device_id *id) | |
373 | { | |
374 | struct lm92_data *data; | |
375 | int err; | |
376 | ||
705375cc GR |
377 | data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data), |
378 | GFP_KERNEL); | |
379 | if (!data) | |
380 | return -ENOMEM; | |
910e8dcf JD |
381 | |
382 | i2c_set_clientdata(new_client, data); | |
1da177e4 | 383 | data->valid = 0; |
9a61bf63 | 384 | mutex_init(&data->update_lock); |
1da177e4 | 385 | |
1da177e4 LT |
386 | /* Initialize the chipset */ |
387 | lm92_init_client(new_client); | |
388 | ||
389 | /* Register sysfs hooks */ | |
a318afd8 GR |
390 | err = sysfs_create_group(&new_client->dev.kobj, &lm92_group); |
391 | if (err) | |
705375cc | 392 | return err; |
0501a381 | 393 | |
1beeffe4 TJ |
394 | data->hwmon_dev = hwmon_device_register(&new_client->dev); |
395 | if (IS_ERR(data->hwmon_dev)) { | |
396 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 397 | goto exit_remove; |
943b0830 MH |
398 | } |
399 | ||
1da177e4 LT |
400 | return 0; |
401 | ||
0501a381 MH |
402 | exit_remove: |
403 | sysfs_remove_group(&new_client->dev.kobj, &lm92_group); | |
1da177e4 LT |
404 | return err; |
405 | } | |
406 | ||
910e8dcf | 407 | static int lm92_remove(struct i2c_client *client) |
1da177e4 | 408 | { |
943b0830 | 409 | struct lm92_data *data = i2c_get_clientdata(client); |
1da177e4 | 410 | |
1beeffe4 | 411 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 412 | sysfs_remove_group(&client->dev.kobj, &lm92_group); |
943b0830 | 413 | |
1da177e4 LT |
414 | return 0; |
415 | } | |
416 | ||
417 | ||
418 | /* | |
419 | * Module and driver stuff | |
420 | */ | |
421 | ||
910e8dcf | 422 | static const struct i2c_device_id lm92_id[] = { |
1f86df49 | 423 | { "lm92", 0 }, |
910e8dcf JD |
424 | /* max6635 could be added here */ |
425 | { } | |
426 | }; | |
427 | MODULE_DEVICE_TABLE(i2c, lm92_id); | |
428 | ||
1da177e4 | 429 | static struct i2c_driver lm92_driver = { |
910e8dcf | 430 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 431 | .driver = { |
cdaf7934 LR |
432 | .name = "lm92", |
433 | }, | |
910e8dcf JD |
434 | .probe = lm92_probe, |
435 | .remove = lm92_remove, | |
436 | .id_table = lm92_id, | |
437 | .detect = lm92_detect, | |
c3813d6a | 438 | .address_list = normal_i2c, |
1da177e4 LT |
439 | }; |
440 | ||
f0967eea | 441 | module_i2c_driver(lm92_driver); |
1da177e4 LT |
442 | |
443 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); | |
444 | MODULE_DESCRIPTION("LM92/MAX6635 driver"); | |
445 | MODULE_LICENSE("GPL"); |