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1da177e4 LT |
1 | /* |
2 | * lm92 - Hardware monitoring driver | |
3 | * Copyright (C) 2005 Jean Delvare <khali@linux-fr.org> | |
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> | |
47 | #include <linux/i2c-sensor.h> | |
943b0830 MH |
48 | #include <linux/hwmon.h> |
49 | #include <linux/err.h> | |
1da177e4 LT |
50 | |
51 | /* The LM92 and MAX6635 have 2 two-state pins for address selection, | |
52 | resulting in 4 possible addresses. */ | |
53 | static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, | |
54 | I2C_CLIENT_END }; | |
1da177e4 LT |
55 | |
56 | /* Insmod parameters */ | |
57 | SENSORS_INSMOD_1(lm92); | |
58 | ||
59 | /* The LM92 registers */ | |
60 | #define LM92_REG_CONFIG 0x01 /* 8-bit, RW */ | |
61 | #define LM92_REG_TEMP 0x00 /* 16-bit, RO */ | |
62 | #define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */ | |
63 | #define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */ | |
64 | #define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */ | |
65 | #define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */ | |
66 | #define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */ | |
67 | ||
68 | /* The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius, | |
69 | left-justified in 16-bit registers. No rounding is done, with such | |
70 | a resolution it's just not worth it. Note that the MAX6635 doesn't | |
71 | make use of the 4 lower bits for limits (i.e. effective resolution | |
72 | for limits is 1 degree Celsius). */ | |
73 | static inline int TEMP_FROM_REG(s16 reg) | |
74 | { | |
75 | return reg / 8 * 625 / 10; | |
76 | } | |
77 | ||
78 | static inline s16 TEMP_TO_REG(int val) | |
79 | { | |
80 | if (val <= -60000) | |
81 | return -60000 * 10 / 625 * 8; | |
82 | if (val >= 160000) | |
83 | return 160000 * 10 / 625 * 8; | |
84 | return val * 10 / 625 * 8; | |
85 | } | |
86 | ||
87 | /* Alarm flags are stored in the 3 LSB of the temperature register */ | |
88 | static inline u8 ALARMS_FROM_REG(s16 reg) | |
89 | { | |
90 | return reg & 0x0007; | |
91 | } | |
92 | ||
93 | /* Driver data (common to all clients) */ | |
94 | static struct i2c_driver lm92_driver; | |
95 | ||
96 | /* Client data (each client gets its own) */ | |
97 | struct lm92_data { | |
98 | struct i2c_client client; | |
943b0830 | 99 | struct class_device *class_dev; |
1da177e4 LT |
100 | struct semaphore update_lock; |
101 | char valid; /* zero until following fields are valid */ | |
102 | unsigned long last_updated; /* in jiffies */ | |
103 | ||
104 | /* registers values */ | |
105 | s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst; | |
106 | }; | |
107 | ||
108 | ||
109 | /* | |
110 | * Sysfs attributes and callback functions | |
111 | */ | |
112 | ||
113 | static struct lm92_data *lm92_update_device(struct device *dev) | |
114 | { | |
115 | struct i2c_client *client = to_i2c_client(dev); | |
116 | struct lm92_data *data = i2c_get_clientdata(client); | |
117 | ||
118 | down(&data->update_lock); | |
119 | ||
120 | if (time_after(jiffies, data->last_updated + HZ) | |
121 | || !data->valid) { | |
122 | dev_dbg(&client->dev, "Updating lm92 data\n"); | |
123 | data->temp1_input = swab16(i2c_smbus_read_word_data(client, | |
124 | LM92_REG_TEMP)); | |
125 | data->temp1_hyst = swab16(i2c_smbus_read_word_data(client, | |
126 | LM92_REG_TEMP_HYST)); | |
127 | data->temp1_crit = swab16(i2c_smbus_read_word_data(client, | |
128 | LM92_REG_TEMP_CRIT)); | |
129 | data->temp1_min = swab16(i2c_smbus_read_word_data(client, | |
130 | LM92_REG_TEMP_LOW)); | |
131 | data->temp1_max = swab16(i2c_smbus_read_word_data(client, | |
132 | LM92_REG_TEMP_HIGH)); | |
133 | ||
134 | data->last_updated = jiffies; | |
135 | data->valid = 1; | |
136 | } | |
137 | ||
138 | up(&data->update_lock); | |
139 | ||
140 | return data; | |
141 | } | |
142 | ||
143 | #define show_temp(value) \ | |
8627f9ba | 144 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
145 | { \ |
146 | struct lm92_data *data = lm92_update_device(dev); \ | |
147 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \ | |
148 | } | |
149 | show_temp(temp1_input); | |
150 | show_temp(temp1_crit); | |
151 | show_temp(temp1_min); | |
152 | show_temp(temp1_max); | |
153 | ||
154 | #define set_temp(value, reg) \ | |
8627f9ba | 155 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \ |
1da177e4 LT |
156 | size_t count) \ |
157 | { \ | |
158 | struct i2c_client *client = to_i2c_client(dev); \ | |
159 | struct lm92_data *data = i2c_get_clientdata(client); \ | |
160 | long val = simple_strtol(buf, NULL, 10); \ | |
161 | \ | |
162 | down(&data->update_lock); \ | |
163 | data->value = TEMP_TO_REG(val); \ | |
164 | i2c_smbus_write_word_data(client, reg, swab16(data->value)); \ | |
165 | up(&data->update_lock); \ | |
166 | return count; \ | |
167 | } | |
168 | set_temp(temp1_crit, LM92_REG_TEMP_CRIT); | |
169 | set_temp(temp1_min, LM92_REG_TEMP_LOW); | |
170 | set_temp(temp1_max, LM92_REG_TEMP_HIGH); | |
171 | ||
8627f9ba | 172 | static ssize_t show_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
173 | { |
174 | struct lm92_data *data = lm92_update_device(dev); | |
175 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit) | |
176 | - TEMP_FROM_REG(data->temp1_hyst)); | |
177 | } | |
8627f9ba | 178 | static ssize_t show_temp1_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
179 | { |
180 | struct lm92_data *data = lm92_update_device(dev); | |
181 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max) | |
182 | - TEMP_FROM_REG(data->temp1_hyst)); | |
183 | } | |
8627f9ba | 184 | static ssize_t show_temp1_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
185 | { |
186 | struct lm92_data *data = lm92_update_device(dev); | |
187 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min) | |
188 | + TEMP_FROM_REG(data->temp1_hyst)); | |
189 | } | |
190 | ||
8627f9ba | 191 | static ssize_t set_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, |
1da177e4 LT |
192 | size_t count) |
193 | { | |
194 | struct i2c_client *client = to_i2c_client(dev); | |
195 | struct lm92_data *data = i2c_get_clientdata(client); | |
196 | long val = simple_strtol(buf, NULL, 10); | |
197 | ||
198 | down(&data->update_lock); | |
199 | data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val; | |
200 | i2c_smbus_write_word_data(client, LM92_REG_TEMP_HYST, | |
201 | swab16(TEMP_TO_REG(data->temp1_hyst))); | |
202 | up(&data->update_lock); | |
203 | return count; | |
204 | } | |
205 | ||
8627f9ba | 206 | static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
207 | { |
208 | struct lm92_data *data = lm92_update_device(dev); | |
209 | return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input)); | |
210 | } | |
211 | ||
212 | static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL); | |
213 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit, | |
214 | set_temp1_crit); | |
215 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst, | |
216 | set_temp1_crit_hyst); | |
217 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min, | |
218 | set_temp1_min); | |
219 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL); | |
220 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max, | |
221 | set_temp1_max); | |
222 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL); | |
223 | static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL); | |
224 | ||
225 | ||
226 | /* | |
227 | * Detection and registration | |
228 | */ | |
229 | ||
230 | static void lm92_init_client(struct i2c_client *client) | |
231 | { | |
232 | u8 config; | |
233 | ||
234 | /* Start the conversions if needed */ | |
235 | config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); | |
236 | if (config & 0x01) | |
237 | i2c_smbus_write_byte_data(client, LM92_REG_CONFIG, | |
238 | config & 0xFE); | |
239 | } | |
240 | ||
241 | /* The MAX6635 has no identification register, so we have to use tricks | |
242 | to identify it reliably. This is somewhat slow. | |
243 | Note that we do NOT rely on the 2 MSB of the configuration register | |
244 | always reading 0, as suggested by the datasheet, because it was once | |
245 | reported not to be true. */ | |
246 | static int max6635_check(struct i2c_client *client) | |
247 | { | |
248 | u16 temp_low, temp_high, temp_hyst, temp_crit; | |
249 | u8 conf; | |
250 | int i; | |
251 | ||
252 | /* No manufacturer ID register, so a read from this address will | |
253 | always return the last read value. */ | |
254 | temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW); | |
255 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low) | |
256 | return 0; | |
257 | temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH); | |
258 | if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high) | |
259 | return 0; | |
260 | ||
261 | /* Limits are stored as integer values (signed, 9-bit). */ | |
262 | if ((temp_low & 0x7f00) || (temp_high & 0x7f00)) | |
263 | return 0; | |
264 | temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST); | |
265 | temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT); | |
266 | if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00)) | |
267 | return 0; | |
268 | ||
269 | /* Registers addresses were found to cycle over 16-byte boundaries. | |
270 | We don't test all registers with all offsets so as to save some | |
271 | reads and time, but this should still be sufficient to dismiss | |
272 | non-MAX6635 chips. */ | |
273 | conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); | |
274 | for (i=16; i<96; i*=2) { | |
275 | if (temp_hyst != i2c_smbus_read_word_data(client, | |
276 | LM92_REG_TEMP_HYST + i - 16) | |
277 | || temp_crit != i2c_smbus_read_word_data(client, | |
278 | LM92_REG_TEMP_CRIT + i) | |
279 | || temp_low != i2c_smbus_read_word_data(client, | |
280 | LM92_REG_TEMP_LOW + i + 16) | |
281 | || temp_high != i2c_smbus_read_word_data(client, | |
282 | LM92_REG_TEMP_HIGH + i + 32) | |
283 | || conf != i2c_smbus_read_byte_data(client, | |
284 | LM92_REG_CONFIG + i)) | |
285 | return 0; | |
286 | } | |
287 | ||
288 | return 1; | |
289 | } | |
290 | ||
291 | /* The following function does more than just detection. If detection | |
292 | succeeds, it also registers the new chip. */ | |
293 | static int lm92_detect(struct i2c_adapter *adapter, int address, int kind) | |
294 | { | |
295 | struct i2c_client *new_client; | |
296 | struct lm92_data *data; | |
297 | int err = 0; | |
298 | char *name; | |
299 | ||
300 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
301 | | I2C_FUNC_SMBUS_WORD_DATA)) | |
302 | goto exit; | |
303 | ||
304 | if (!(data = kmalloc(sizeof(struct lm92_data), GFP_KERNEL))) { | |
305 | err = -ENOMEM; | |
306 | goto exit; | |
307 | } | |
308 | memset(data, 0, sizeof(struct lm92_data)); | |
309 | ||
310 | /* Fill in enough client fields so that we can read from the chip, | |
311 | which is required for identication */ | |
312 | new_client = &data->client; | |
313 | i2c_set_clientdata(new_client, data); | |
314 | new_client->addr = address; | |
315 | new_client->adapter = adapter; | |
316 | new_client->driver = &lm92_driver; | |
317 | new_client->flags = 0; | |
318 | ||
319 | /* A negative kind means that the driver was loaded with no force | |
320 | parameter (default), so we must identify the chip. */ | |
321 | if (kind < 0) { | |
322 | u8 config = i2c_smbus_read_byte_data(new_client, | |
323 | LM92_REG_CONFIG); | |
324 | u16 man_id = i2c_smbus_read_word_data(new_client, | |
325 | LM92_REG_MAN_ID); | |
326 | ||
327 | if ((config & 0xe0) == 0x00 | |
328 | && man_id == 0x0180) { | |
329 | pr_info("lm92: Found National Semiconductor LM92 chip\n"); | |
330 | kind = lm92; | |
331 | } else | |
332 | if (max6635_check(new_client)) { | |
333 | pr_info("lm92: Found Maxim MAX6635 chip\n"); | |
334 | kind = lm92; /* No separate prefix */ | |
335 | } | |
336 | else | |
337 | goto exit_free; | |
338 | } else | |
339 | if (kind == 0) /* Default to an LM92 if forced */ | |
340 | kind = lm92; | |
341 | ||
342 | /* Give it the proper name */ | |
343 | if (kind == lm92) { | |
344 | name = "lm92"; | |
345 | } else { /* Supposedly cannot happen */ | |
346 | dev_dbg(&new_client->dev, "Kind out of range?\n"); | |
347 | goto exit_free; | |
348 | } | |
349 | ||
350 | /* Fill in the remaining client fields */ | |
351 | strlcpy(new_client->name, name, I2C_NAME_SIZE); | |
352 | data->valid = 0; | |
353 | init_MUTEX(&data->update_lock); | |
354 | ||
355 | /* Tell the i2c subsystem a new client has arrived */ | |
356 | if ((err = i2c_attach_client(new_client))) | |
357 | goto exit_free; | |
358 | ||
359 | /* Initialize the chipset */ | |
360 | lm92_init_client(new_client); | |
361 | ||
362 | /* Register sysfs hooks */ | |
943b0830 MH |
363 | data->class_dev = hwmon_device_register(&new_client->dev); |
364 | if (IS_ERR(data->class_dev)) { | |
365 | err = PTR_ERR(data->class_dev); | |
366 | goto exit_detach; | |
367 | } | |
368 | ||
1da177e4 LT |
369 | device_create_file(&new_client->dev, &dev_attr_temp1_input); |
370 | device_create_file(&new_client->dev, &dev_attr_temp1_crit); | |
371 | device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst); | |
372 | device_create_file(&new_client->dev, &dev_attr_temp1_min); | |
373 | device_create_file(&new_client->dev, &dev_attr_temp1_min_hyst); | |
374 | device_create_file(&new_client->dev, &dev_attr_temp1_max); | |
375 | device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst); | |
376 | device_create_file(&new_client->dev, &dev_attr_alarms); | |
377 | ||
378 | return 0; | |
379 | ||
943b0830 MH |
380 | exit_detach: |
381 | i2c_detach_client(new_client); | |
1da177e4 LT |
382 | exit_free: |
383 | kfree(data); | |
384 | exit: | |
385 | return err; | |
386 | } | |
387 | ||
388 | static int lm92_attach_adapter(struct i2c_adapter *adapter) | |
389 | { | |
390 | if (!(adapter->class & I2C_CLASS_HWMON)) | |
391 | return 0; | |
2ed2dc3c | 392 | return i2c_probe(adapter, &addr_data, lm92_detect); |
1da177e4 LT |
393 | } |
394 | ||
395 | static int lm92_detach_client(struct i2c_client *client) | |
396 | { | |
943b0830 | 397 | struct lm92_data *data = i2c_get_clientdata(client); |
1da177e4 LT |
398 | int err; |
399 | ||
943b0830 MH |
400 | hwmon_device_unregister(data->class_dev); |
401 | ||
7bef5594 | 402 | if ((err = i2c_detach_client(client))) |
1da177e4 | 403 | return err; |
1da177e4 | 404 | |
943b0830 | 405 | kfree(data); |
1da177e4 LT |
406 | return 0; |
407 | } | |
408 | ||
409 | ||
410 | /* | |
411 | * Module and driver stuff | |
412 | */ | |
413 | ||
414 | static struct i2c_driver lm92_driver = { | |
415 | .owner = THIS_MODULE, | |
416 | .name = "lm92", | |
417 | .id = I2C_DRIVERID_LM92, | |
418 | .flags = I2C_DF_NOTIFY, | |
419 | .attach_adapter = lm92_attach_adapter, | |
420 | .detach_client = lm92_detach_client, | |
421 | }; | |
422 | ||
423 | static int __init sensors_lm92_init(void) | |
424 | { | |
425 | return i2c_add_driver(&lm92_driver); | |
426 | } | |
427 | ||
428 | static void __exit sensors_lm92_exit(void) | |
429 | { | |
430 | i2c_del_driver(&lm92_driver); | |
431 | } | |
432 | ||
433 | MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>"); | |
434 | MODULE_DESCRIPTION("LM92/MAX6635 driver"); | |
435 | MODULE_LICENSE("GPL"); | |
436 | ||
437 | module_init(sensors_lm92_init); | |
438 | module_exit(sensors_lm92_exit); |