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1da177e4 LT |
1 | /* |
2 | * lm92 - Hardware monitoring driver | |
7c81c60f | 3 | * Copyright (C) 2005-2008 Jean Delvare <jdelvare@suse.de> |
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. | |
1da177e4 LT |
37 | */ |
38 | ||
39 | #include <linux/module.h> | |
40 | #include <linux/init.h> | |
41 | #include <linux/slab.h> | |
42 | #include <linux/i2c.h> | |
943b0830 | 43 | #include <linux/hwmon.h> |
6cb59e91 | 44 | #include <linux/hwmon-sysfs.h> |
943b0830 | 45 | #include <linux/err.h> |
9a61bf63 | 46 | #include <linux/mutex.h> |
dcd8f392 | 47 | #include <linux/jiffies.h> |
1da177e4 | 48 | |
a318afd8 GR |
49 | /* |
50 | * The LM92 and MAX6635 have 2 two-state pins for address selection, | |
51 | * resulting in 4 possible addresses. | |
52 | */ | |
25e9c86d MH |
53 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
54 | I2C_CLIENT_END }; | |
1da177e4 | 55 | |
1da177e4 LT |
56 | /* The LM92 registers */ |
57 | #define LM92_REG_CONFIG 0x01 /* 8-bit, RW */ | |
58 | #define LM92_REG_TEMP 0x00 /* 16-bit, RO */ | |
59 | #define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */ | |
60 | #define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */ | |
61 | #define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */ | |
62 | #define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */ | |
63 | #define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */ | |
64 | ||
a318afd8 GR |
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 | */ | |
1da177e4 LT |
72 | static inline int TEMP_FROM_REG(s16 reg) |
73 | { | |
74 | return reg / 8 * 625 / 10; | |
75 | } | |
76 | ||
77 | static inline s16 TEMP_TO_REG(int val) | |
78 | { | |
79 | if (val <= -60000) | |
80 | return -60000 * 10 / 625 * 8; | |
81 | if (val >= 160000) | |
82 | return 160000 * 10 / 625 * 8; | |
83 | return val * 10 / 625 * 8; | |
84 | } | |
85 | ||
86 | /* Alarm flags are stored in the 3 LSB of the temperature register */ | |
87 | static inline u8 ALARMS_FROM_REG(s16 reg) | |
88 | { | |
89 | return reg & 0x0007; | |
90 | } | |
91 | ||
b8fe58e9 GR |
92 | enum temp_index { |
93 | t_input, | |
94 | t_crit, | |
95 | t_min, | |
96 | t_max, | |
97 | t_hyst, | |
98 | t_num_regs | |
99 | }; | |
100 | ||
101 | static const u8 regs[t_num_regs] = { | |
102 | [t_input] = LM92_REG_TEMP, | |
103 | [t_crit] = LM92_REG_TEMP_CRIT, | |
104 | [t_min] = LM92_REG_TEMP_LOW, | |
105 | [t_max] = LM92_REG_TEMP_HIGH, | |
106 | [t_hyst] = LM92_REG_TEMP_HYST, | |
107 | }; | |
108 | ||
1da177e4 LT |
109 | /* Client data (each client gets its own) */ |
110 | struct lm92_data { | |
030004b1 | 111 | struct i2c_client *client; |
9a61bf63 | 112 | struct mutex update_lock; |
1da177e4 LT |
113 | char valid; /* zero until following fields are valid */ |
114 | unsigned long last_updated; /* in jiffies */ | |
115 | ||
116 | /* registers values */ | |
b8fe58e9 | 117 | s16 temp[t_num_regs]; /* index with enum temp_index */ |
1da177e4 LT |
118 | }; |
119 | ||
1da177e4 LT |
120 | /* |
121 | * Sysfs attributes and callback functions | |
122 | */ | |
123 | ||
124 | static struct lm92_data *lm92_update_device(struct device *dev) | |
125 | { | |
030004b1 GR |
126 | struct lm92_data *data = dev_get_drvdata(dev); |
127 | struct i2c_client *client = data->client; | |
b8fe58e9 | 128 | int i; |
1da177e4 | 129 | |
9a61bf63 | 130 | mutex_lock(&data->update_lock); |
1da177e4 LT |
131 | |
132 | if (time_after(jiffies, data->last_updated + HZ) | |
133 | || !data->valid) { | |
134 | dev_dbg(&client->dev, "Updating lm92 data\n"); | |
b8fe58e9 GR |
135 | for (i = 0; i < t_num_regs; i++) { |
136 | data->temp[i] = | |
137 | i2c_smbus_read_word_swapped(client, regs[i]); | |
138 | } | |
1da177e4 LT |
139 | data->last_updated = jiffies; |
140 | data->valid = 1; | |
141 | } | |
142 | ||
9a61bf63 | 143 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
144 | |
145 | return data; | |
146 | } | |
147 | ||
b8fe58e9 GR |
148 | static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, |
149 | char *buf) | |
150 | { | |
151 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); | |
152 | struct lm92_data *data = lm92_update_device(dev); | |
153 | ||
154 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])); | |
1da177e4 | 155 | } |
1da177e4 | 156 | |
b8fe58e9 GR |
157 | static ssize_t set_temp(struct device *dev, struct device_attribute *devattr, |
158 | const char *buf, size_t count) | |
1da177e4 | 159 | { |
b8fe58e9 | 160 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
030004b1 GR |
161 | struct lm92_data *data = dev_get_drvdata(dev); |
162 | struct i2c_client *client = data->client; | |
b8fe58e9 GR |
163 | int nr = attr->index; |
164 | long val; | |
165 | int err; | |
166 | ||
167 | err = kstrtol(buf, 10, &val); | |
168 | if (err) | |
169 | return err; | |
170 | ||
171 | mutex_lock(&data->update_lock); | |
172 | data->temp[nr] = TEMP_TO_REG(val); | |
173 | i2c_smbus_write_word_swapped(client, regs[nr], data->temp[nr]); | |
174 | mutex_unlock(&data->update_lock); | |
175 | return count; | |
1da177e4 | 176 | } |
b8fe58e9 GR |
177 | |
178 | static ssize_t show_temp_hyst(struct device *dev, | |
179 | struct device_attribute *devattr, char *buf) | |
1da177e4 | 180 | { |
b8fe58e9 | 181 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
1da177e4 | 182 | struct lm92_data *data = lm92_update_device(dev); |
b8fe58e9 GR |
183 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]) |
184 | - TEMP_FROM_REG(data->temp[t_hyst])); | |
1da177e4 | 185 | } |
b8fe58e9 GR |
186 | |
187 | static ssize_t show_temp_min_hyst(struct device *dev, | |
188 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
189 | { |
190 | struct lm92_data *data = lm92_update_device(dev); | |
b8fe58e9 GR |
191 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[t_min]) |
192 | + TEMP_FROM_REG(data->temp[t_hyst])); | |
1da177e4 LT |
193 | } |
194 | ||
b8fe58e9 GR |
195 | static ssize_t set_temp_hyst(struct device *dev, |
196 | struct device_attribute *devattr, | |
197 | const char *buf, size_t count) | |
1da177e4 | 198 | { |
b8fe58e9 | 199 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
030004b1 GR |
200 | struct lm92_data *data = dev_get_drvdata(dev); |
201 | struct i2c_client *client = data->client; | |
a318afd8 GR |
202 | long val; |
203 | int err; | |
204 | ||
205 | err = kstrtol(buf, 10, &val); | |
206 | if (err) | |
207 | return err; | |
1da177e4 | 208 | |
9a61bf63 | 209 | mutex_lock(&data->update_lock); |
b8fe58e9 | 210 | data->temp[t_hyst] = TEMP_FROM_REG(data->temp[attr->index]) - val; |
90f4102c | 211 | i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST, |
b8fe58e9 | 212 | TEMP_TO_REG(data->temp[t_hyst])); |
9a61bf63 | 213 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
214 | return count; |
215 | } | |
216 | ||
a318afd8 GR |
217 | static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, |
218 | char *buf) | |
1da177e4 LT |
219 | { |
220 | struct lm92_data *data = lm92_update_device(dev); | |
b8fe58e9 | 221 | return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp[t_input])); |
1da177e4 LT |
222 | } |
223 | ||
6cb59e91 JD |
224 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
225 | char *buf) | |
226 | { | |
227 | int bitnr = to_sensor_dev_attr(attr)->index; | |
228 | struct lm92_data *data = lm92_update_device(dev); | |
b8fe58e9 | 229 | return sprintf(buf, "%d\n", (data->temp[t_input] >> bitnr) & 1); |
6cb59e91 JD |
230 | } |
231 | ||
b8fe58e9 GR |
232 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input); |
233 | static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp, set_temp, | |
234 | t_crit); | |
235 | static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, | |
236 | set_temp_hyst, t_crit); | |
237 | static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, | |
238 | t_min); | |
239 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp_min_hyst, NULL); | |
240 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, | |
241 | t_max); | |
242 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max); | |
1da177e4 | 243 | static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); |
6cb59e91 JD |
244 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
245 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
246 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 | 247 | |
1da177e4 LT |
248 | /* |
249 | * Detection and registration | |
250 | */ | |
251 | ||
252 | static void lm92_init_client(struct i2c_client *client) | |
253 | { | |
254 | u8 config; | |
255 | ||
256 | /* Start the conversions if needed */ | |
257 | config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); | |
258 | if (config & 0x01) | |
259 | i2c_smbus_write_byte_data(client, LM92_REG_CONFIG, | |
260 | config & 0xFE); | |
261 | } | |
262 | ||
a318afd8 GR |
263 | /* |
264 | * The MAX6635 has no identification register, so we have to use tricks | |
265 | * to identify it reliably. This is somewhat slow. | |
266 | * Note that we do NOT rely on the 2 MSB of the configuration register | |
267 | * always reading 0, as suggested by the datasheet, because it was once | |
268 | * reported not to be true. | |
269 | */ | |
1da177e4 LT |
270 | static int max6635_check(struct i2c_client *client) |
271 | { | |
272 | u16 temp_low, temp_high, temp_hyst, temp_crit; | |
273 | u8 conf; | |
274 | int i; | |
275 | ||
a318afd8 GR |
276 | /* |
277 | * No manufacturer ID register, so a read from this address will | |
278 | * always return the last read value. | |
279 | */ | |
1da177e4 LT |
280 | temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW); |
281 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low) | |
282 | return 0; | |
283 | temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH); | |
284 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high) | |
285 | return 0; | |
a318afd8 | 286 | |
1da177e4 LT |
287 | /* Limits are stored as integer values (signed, 9-bit). */ |
288 | if ((temp_low & 0x7f00) || (temp_high & 0x7f00)) | |
289 | return 0; | |
290 | temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST); | |
291 | temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT); | |
292 | if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00)) | |
293 | return 0; | |
294 | ||
a318afd8 GR |
295 | /* |
296 | * Registers addresses were found to cycle over 16-byte boundaries. | |
297 | * We don't test all registers with all offsets so as to save some | |
298 | * reads and time, but this should still be sufficient to dismiss | |
299 | * non-MAX6635 chips. | |
300 | */ | |
1da177e4 | 301 | conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); |
a318afd8 | 302 | for (i = 16; i < 96; i *= 2) { |
1da177e4 | 303 | if (temp_hyst != i2c_smbus_read_word_data(client, |
a318afd8 | 304 | LM92_REG_TEMP_HYST + i - 16) |
1da177e4 | 305 | || temp_crit != i2c_smbus_read_word_data(client, |
a318afd8 | 306 | LM92_REG_TEMP_CRIT + i) |
1da177e4 LT |
307 | || temp_low != i2c_smbus_read_word_data(client, |
308 | LM92_REG_TEMP_LOW + i + 16) | |
309 | || temp_high != i2c_smbus_read_word_data(client, | |
a318afd8 | 310 | LM92_REG_TEMP_HIGH + i + 32) |
1da177e4 | 311 | || conf != i2c_smbus_read_byte_data(client, |
a318afd8 | 312 | LM92_REG_CONFIG + i)) |
1da177e4 LT |
313 | return 0; |
314 | } | |
315 | ||
316 | return 1; | |
317 | } | |
318 | ||
030004b1 | 319 | static struct attribute *lm92_attrs[] = { |
b8fe58e9 GR |
320 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
321 | &sensor_dev_attr_temp1_crit.dev_attr.attr, | |
322 | &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, | |
323 | &sensor_dev_attr_temp1_min.dev_attr.attr, | |
0501a381 | 324 | &dev_attr_temp1_min_hyst.attr, |
b8fe58e9 GR |
325 | &sensor_dev_attr_temp1_max.dev_attr.attr, |
326 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
0501a381 | 327 | &dev_attr_alarms.attr, |
6cb59e91 JD |
328 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
329 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
330 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
331 | NULL |
332 | }; | |
030004b1 | 333 | ATTRIBUTE_GROUPS(lm92); |
0501a381 | 334 | |
910e8dcf | 335 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 336 | static int lm92_detect(struct i2c_client *new_client, |
910e8dcf | 337 | struct i2c_board_info *info) |
1da177e4 | 338 | { |
910e8dcf | 339 | struct i2c_adapter *adapter = new_client->adapter; |
52df6440 JD |
340 | u8 config; |
341 | u16 man_id; | |
1da177e4 LT |
342 | |
343 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
344 | | I2C_FUNC_SMBUS_WORD_DATA)) | |
910e8dcf | 345 | return -ENODEV; |
1da177e4 | 346 | |
52df6440 JD |
347 | config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG); |
348 | man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID); | |
349 | ||
350 | if ((config & 0xe0) == 0x00 && man_id == 0x0180) | |
351 | pr_info("lm92: Found National Semiconductor LM92 chip\n"); | |
352 | else if (max6635_check(new_client)) | |
353 | pr_info("lm92: Found Maxim MAX6635 chip\n"); | |
354 | else | |
355 | return -ENODEV; | |
1da177e4 | 356 | |
910e8dcf JD |
357 | strlcpy(info->type, "lm92", I2C_NAME_SIZE); |
358 | ||
359 | return 0; | |
360 | } | |
361 | ||
362 | static int lm92_probe(struct i2c_client *new_client, | |
363 | const struct i2c_device_id *id) | |
364 | { | |
030004b1 | 365 | struct device *hwmon_dev; |
910e8dcf | 366 | struct lm92_data *data; |
910e8dcf | 367 | |
705375cc GR |
368 | data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data), |
369 | GFP_KERNEL); | |
370 | if (!data) | |
371 | return -ENOMEM; | |
910e8dcf | 372 | |
030004b1 | 373 | data->client = new_client; |
9a61bf63 | 374 | mutex_init(&data->update_lock); |
1da177e4 | 375 | |
1da177e4 LT |
376 | /* Initialize the chipset */ |
377 | lm92_init_client(new_client); | |
378 | ||
030004b1 GR |
379 | hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev, |
380 | new_client->name, | |
381 | data, lm92_groups); | |
382 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
1da177e4 LT |
383 | } |
384 | ||
385 | ||
386 | /* | |
387 | * Module and driver stuff | |
388 | */ | |
389 | ||
910e8dcf | 390 | static const struct i2c_device_id lm92_id[] = { |
1f86df49 | 391 | { "lm92", 0 }, |
910e8dcf JD |
392 | /* max6635 could be added here */ |
393 | { } | |
394 | }; | |
395 | MODULE_DEVICE_TABLE(i2c, lm92_id); | |
396 | ||
1da177e4 | 397 | static struct i2c_driver lm92_driver = { |
910e8dcf | 398 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 399 | .driver = { |
cdaf7934 LR |
400 | .name = "lm92", |
401 | }, | |
910e8dcf | 402 | .probe = lm92_probe, |
910e8dcf JD |
403 | .id_table = lm92_id, |
404 | .detect = lm92_detect, | |
c3813d6a | 405 | .address_list = normal_i2c, |
1da177e4 LT |
406 | }; |
407 | ||
f0967eea | 408 | module_i2c_driver(lm92_driver); |
1da177e4 | 409 | |
7c81c60f | 410 | MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); |
1da177e4 LT |
411 | MODULE_DESCRIPTION("LM92/MAX6635 driver"); |
412 | MODULE_LICENSE("GPL"); |