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1da177e4 LT |
1 | /* |
2 | lm77.c - Part of lm_sensors, Linux kernel modules for hardware | |
3 | monitoring | |
4 | ||
5 | Copyright (c) 2004 Andras BALI <drewie@freemail.hu> | |
6 | ||
7 | Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77 | |
8 | is a temperature sensor and thermal window comparator with 0.5 deg | |
9 | resolution made by National Semiconductor. Complete datasheet can be | |
10 | obtained at their site: | |
11 | http://www.national.com/pf/LM/LM77.html | |
12 | ||
13 | This program is free software; you can redistribute it and/or modify | |
14 | it under the terms of the GNU General Public License as published by | |
15 | the Free Software Foundation; either version 2 of the License, or | |
16 | (at your option) any later version. | |
17 | ||
18 | This program is distributed in the hope that it will be useful, | |
19 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
20 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
21 | GNU General Public License for more details. | |
22 | ||
23 | You should have received a copy of the GNU General Public License | |
24 | along with this program; if not, write to the Free Software | |
25 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
26 | */ | |
27 | ||
1da177e4 LT |
28 | #include <linux/module.h> |
29 | #include <linux/init.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/jiffies.h> | |
32 | #include <linux/i2c.h> | |
943b0830 MH |
33 | #include <linux/hwmon.h> |
34 | #include <linux/err.h> | |
9a61bf63 | 35 | #include <linux/mutex.h> |
1da177e4 LT |
36 | |
37 | /* Addresses to scan */ | |
38 | static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END }; | |
1da177e4 LT |
39 | |
40 | /* Insmod parameters */ | |
f4b50261 | 41 | I2C_CLIENT_INSMOD_1(lm77); |
1da177e4 LT |
42 | |
43 | /* The LM77 registers */ | |
44 | #define LM77_REG_TEMP 0x00 | |
45 | #define LM77_REG_CONF 0x01 | |
46 | #define LM77_REG_TEMP_HYST 0x02 | |
47 | #define LM77_REG_TEMP_CRIT 0x03 | |
48 | #define LM77_REG_TEMP_MIN 0x04 | |
49 | #define LM77_REG_TEMP_MAX 0x05 | |
50 | ||
51 | /* Each client has this additional data */ | |
52 | struct lm77_data { | |
53 | struct i2c_client client; | |
943b0830 | 54 | struct class_device *class_dev; |
9a61bf63 | 55 | struct mutex update_lock; |
1da177e4 LT |
56 | char valid; |
57 | unsigned long last_updated; /* In jiffies */ | |
58 | int temp_input; /* Temperatures */ | |
59 | int temp_crit; | |
60 | int temp_min; | |
61 | int temp_max; | |
62 | int temp_hyst; | |
63 | u8 alarms; | |
64 | }; | |
65 | ||
66 | static int lm77_attach_adapter(struct i2c_adapter *adapter); | |
67 | static int lm77_detect(struct i2c_adapter *adapter, int address, int kind); | |
68 | static void lm77_init_client(struct i2c_client *client); | |
69 | static int lm77_detach_client(struct i2c_client *client); | |
70 | static u16 lm77_read_value(struct i2c_client *client, u8 reg); | |
71 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value); | |
72 | ||
73 | static struct lm77_data *lm77_update_device(struct device *dev); | |
74 | ||
75 | ||
76 | /* This is the driver that will be inserted */ | |
77 | static struct i2c_driver lm77_driver = { | |
cdaf7934 | 78 | .driver = { |
cdaf7934 LR |
79 | .name = "lm77", |
80 | }, | |
1da177e4 LT |
81 | .attach_adapter = lm77_attach_adapter, |
82 | .detach_client = lm77_detach_client, | |
83 | }; | |
84 | ||
85 | /* straight from the datasheet */ | |
86 | #define LM77_TEMP_MIN (-55000) | |
87 | #define LM77_TEMP_MAX 125000 | |
88 | ||
89 | /* In the temperature registers, the low 3 bits are not part of the | |
90 | temperature values; they are the status bits. */ | |
413b6451 | 91 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 LT |
92 | { |
93 | int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); | |
413b6451 | 94 | return (ntemp / 500) * 8; |
1da177e4 LT |
95 | } |
96 | ||
413b6451 | 97 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 98 | { |
413b6451 | 99 | return (reg / 8) * 500; |
1da177e4 LT |
100 | } |
101 | ||
102 | /* sysfs stuff */ | |
103 | ||
104 | /* read routines for temperature limits */ | |
105 | #define show(value) \ | |
8627f9ba | 106 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
107 | { \ |
108 | struct lm77_data *data = lm77_update_device(dev); \ | |
109 | return sprintf(buf, "%d\n", data->value); \ | |
110 | } | |
111 | ||
112 | show(temp_input); | |
113 | show(temp_crit); | |
114 | show(temp_min); | |
115 | show(temp_max); | |
116 | show(alarms); | |
117 | ||
118 | /* read routines for hysteresis values */ | |
8627f9ba | 119 | static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
120 | { |
121 | struct lm77_data *data = lm77_update_device(dev); | |
122 | return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); | |
123 | } | |
8627f9ba | 124 | static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
125 | { |
126 | struct lm77_data *data = lm77_update_device(dev); | |
127 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
128 | } | |
8627f9ba | 129 | static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
130 | { |
131 | struct lm77_data *data = lm77_update_device(dev); | |
132 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
133 | } | |
134 | ||
135 | /* write routines */ | |
136 | #define set(value, reg) \ | |
8627f9ba | 137 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \ |
1da177e4 LT |
138 | { \ |
139 | struct i2c_client *client = to_i2c_client(dev); \ | |
140 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
141 | long val = simple_strtoul(buf, NULL, 10); \ | |
142 | \ | |
9a61bf63 | 143 | mutex_lock(&data->update_lock); \ |
1da177e4 LT |
144 | data->value = val; \ |
145 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
9a61bf63 | 146 | mutex_unlock(&data->update_lock); \ |
1da177e4 LT |
147 | return count; \ |
148 | } | |
149 | ||
150 | set(temp_min, LM77_REG_TEMP_MIN); | |
151 | set(temp_max, LM77_REG_TEMP_MAX); | |
152 | ||
153 | /* hysteresis is stored as a relative value on the chip, so it has to be | |
154 | converted first */ | |
8627f9ba | 155 | static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
156 | { |
157 | struct i2c_client *client = to_i2c_client(dev); | |
158 | struct lm77_data *data = i2c_get_clientdata(client); | |
159 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
160 | ||
9a61bf63 | 161 | mutex_lock(&data->update_lock); |
1da177e4 LT |
162 | data->temp_hyst = data->temp_crit - val; |
163 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
164 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 165 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
166 | return count; |
167 | } | |
168 | ||
169 | /* preserve hysteresis when setting T_crit */ | |
8627f9ba | 170 | static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
171 | { |
172 | struct i2c_client *client = to_i2c_client(dev); | |
173 | struct lm77_data *data = i2c_get_clientdata(client); | |
174 | long val = simple_strtoul(buf, NULL, 10); | |
175 | int oldcrithyst; | |
176 | ||
9a61bf63 | 177 | mutex_lock(&data->update_lock); |
1da177e4 LT |
178 | oldcrithyst = data->temp_crit - data->temp_hyst; |
179 | data->temp_crit = val; | |
180 | data->temp_hyst = data->temp_crit - oldcrithyst; | |
181 | lm77_write_value(client, LM77_REG_TEMP_CRIT, | |
182 | LM77_TEMP_TO_REG(data->temp_crit)); | |
183 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
184 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 185 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
186 | return count; |
187 | } | |
188 | ||
189 | static DEVICE_ATTR(temp1_input, S_IRUGO, | |
190 | show_temp_input, NULL); | |
191 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
192 | show_temp_crit, set_temp_crit); | |
193 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
194 | show_temp_min, set_temp_min); | |
195 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
196 | show_temp_max, set_temp_max); | |
197 | ||
198 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
199 | show_temp_crit_hyst, set_temp_crit_hyst); | |
200 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
201 | show_temp_min_hyst, NULL); | |
202 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
203 | show_temp_max_hyst, NULL); | |
204 | ||
205 | static DEVICE_ATTR(alarms, S_IRUGO, | |
206 | show_alarms, NULL); | |
207 | ||
208 | static int lm77_attach_adapter(struct i2c_adapter *adapter) | |
209 | { | |
210 | if (!(adapter->class & I2C_CLASS_HWMON)) | |
211 | return 0; | |
2ed2dc3c | 212 | return i2c_probe(adapter, &addr_data, lm77_detect); |
1da177e4 LT |
213 | } |
214 | ||
0501a381 MH |
215 | static struct attribute *lm77_attributes[] = { |
216 | &dev_attr_temp1_input.attr, | |
217 | &dev_attr_temp1_crit.attr, | |
218 | &dev_attr_temp1_min.attr, | |
219 | &dev_attr_temp1_max.attr, | |
220 | &dev_attr_temp1_crit_hyst.attr, | |
221 | &dev_attr_temp1_min_hyst.attr, | |
222 | &dev_attr_temp1_max_hyst.attr, | |
223 | &dev_attr_alarms.attr, | |
224 | ||
225 | NULL | |
226 | }; | |
227 | ||
228 | static const struct attribute_group lm77_group = { | |
229 | .attrs = lm77_attributes, | |
230 | }; | |
231 | ||
2ed2dc3c | 232 | /* This function is called by i2c_probe */ |
1da177e4 LT |
233 | static int lm77_detect(struct i2c_adapter *adapter, int address, int kind) |
234 | { | |
235 | struct i2c_client *new_client; | |
236 | struct lm77_data *data; | |
237 | int err = 0; | |
238 | const char *name = ""; | |
239 | ||
240 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
241 | I2C_FUNC_SMBUS_WORD_DATA)) | |
242 | goto exit; | |
243 | ||
244 | /* OK. For now, we presume we have a valid client. We now create the | |
245 | client structure, even though we cannot fill it completely yet. | |
246 | But it allows us to access lm77_{read,write}_value. */ | |
ba9c2e8d | 247 | if (!(data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL))) { |
1da177e4 LT |
248 | err = -ENOMEM; |
249 | goto exit; | |
250 | } | |
1da177e4 LT |
251 | |
252 | new_client = &data->client; | |
253 | i2c_set_clientdata(new_client, data); | |
254 | new_client->addr = address; | |
255 | new_client->adapter = adapter; | |
256 | new_client->driver = &lm77_driver; | |
257 | new_client->flags = 0; | |
258 | ||
259 | /* Here comes the remaining detection. Since the LM77 has no | |
260 | register dedicated to identification, we have to rely on the | |
261 | following tricks: | |
262 | ||
263 | 1. the high 4 bits represent the sign and thus they should | |
264 | always be the same | |
265 | 2. the high 3 bits are unused in the configuration register | |
266 | 3. addresses 0x06 and 0x07 return the last read value | |
267 | 4. registers cycling over 8-address boundaries | |
268 | ||
269 | Word-sized registers are high-byte first. */ | |
270 | if (kind < 0) { | |
271 | int i, cur, conf, hyst, crit, min, max; | |
272 | ||
273 | /* addresses cycling */ | |
274 | cur = i2c_smbus_read_word_data(new_client, 0); | |
275 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
276 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
277 | crit = i2c_smbus_read_word_data(new_client, 3); | |
278 | min = i2c_smbus_read_word_data(new_client, 4); | |
279 | max = i2c_smbus_read_word_data(new_client, 5); | |
280 | for (i = 8; i <= 0xff; i += 8) | |
281 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
282 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
283 | || i2c_smbus_read_word_data(new_client, i + 3) != crit | |
284 | || i2c_smbus_read_word_data(new_client, i + 4) != min | |
285 | || i2c_smbus_read_word_data(new_client, i + 5) != max) | |
286 | goto exit_free; | |
287 | ||
288 | /* sign bits */ | |
289 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
290 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
291 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
292 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
293 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
294 | goto exit_free; | |
295 | ||
296 | /* unused bits */ | |
297 | if (conf & 0xe0) | |
298 | goto exit_free; | |
299 | ||
300 | /* 0x06 and 0x07 return the last read value */ | |
301 | cur = i2c_smbus_read_word_data(new_client, 0); | |
302 | if (i2c_smbus_read_word_data(new_client, 6) != cur | |
303 | || i2c_smbus_read_word_data(new_client, 7) != cur) | |
304 | goto exit_free; | |
305 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
306 | if (i2c_smbus_read_word_data(new_client, 6) != hyst | |
307 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
308 | goto exit_free; | |
309 | min = i2c_smbus_read_word_data(new_client, 4); | |
310 | if (i2c_smbus_read_word_data(new_client, 6) != min | |
311 | || i2c_smbus_read_word_data(new_client, 7) != min) | |
312 | goto exit_free; | |
313 | ||
314 | } | |
315 | ||
316 | /* Determine the chip type - only one kind supported! */ | |
317 | if (kind <= 0) | |
318 | kind = lm77; | |
319 | ||
320 | if (kind == lm77) { | |
321 | name = "lm77"; | |
322 | } | |
323 | ||
324 | /* Fill in the remaining client fields and put it into the global list */ | |
325 | strlcpy(new_client->name, name, I2C_NAME_SIZE); | |
326 | data->valid = 0; | |
9a61bf63 | 327 | mutex_init(&data->update_lock); |
1da177e4 LT |
328 | |
329 | /* Tell the I2C layer a new client has arrived */ | |
330 | if ((err = i2c_attach_client(new_client))) | |
331 | goto exit_free; | |
332 | ||
333 | /* Initialize the LM77 chip */ | |
334 | lm77_init_client(new_client); | |
335 | ||
336 | /* Register sysfs hooks */ | |
0501a381 MH |
337 | if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group))) |
338 | goto exit_detach; | |
339 | ||
943b0830 MH |
340 | data->class_dev = hwmon_device_register(&new_client->dev); |
341 | if (IS_ERR(data->class_dev)) { | |
342 | err = PTR_ERR(data->class_dev); | |
0501a381 | 343 | goto exit_remove; |
943b0830 MH |
344 | } |
345 | ||
1da177e4 LT |
346 | return 0; |
347 | ||
0501a381 MH |
348 | exit_remove: |
349 | sysfs_remove_group(&new_client->dev.kobj, &lm77_group); | |
943b0830 MH |
350 | exit_detach: |
351 | i2c_detach_client(new_client); | |
1da177e4 LT |
352 | exit_free: |
353 | kfree(data); | |
354 | exit: | |
355 | return err; | |
356 | } | |
357 | ||
358 | static int lm77_detach_client(struct i2c_client *client) | |
359 | { | |
943b0830 MH |
360 | struct lm77_data *data = i2c_get_clientdata(client); |
361 | hwmon_device_unregister(data->class_dev); | |
0501a381 | 362 | sysfs_remove_group(&client->dev.kobj, &lm77_group); |
1da177e4 | 363 | i2c_detach_client(client); |
943b0830 | 364 | kfree(data); |
1da177e4 LT |
365 | return 0; |
366 | } | |
367 | ||
368 | /* All registers are word-sized, except for the configuration register. | |
369 | The LM77 uses the high-byte first convention. */ | |
370 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
371 | { | |
372 | if (reg == LM77_REG_CONF) | |
373 | return i2c_smbus_read_byte_data(client, reg); | |
374 | else | |
375 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
376 | } | |
377 | ||
378 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
379 | { | |
380 | if (reg == LM77_REG_CONF) | |
381 | return i2c_smbus_write_byte_data(client, reg, value); | |
382 | else | |
383 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
384 | } | |
385 | ||
386 | static void lm77_init_client(struct i2c_client *client) | |
387 | { | |
388 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
389 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
390 | if (conf & 1) | |
391 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
392 | } | |
393 | ||
394 | static struct lm77_data *lm77_update_device(struct device *dev) | |
395 | { | |
396 | struct i2c_client *client = to_i2c_client(dev); | |
397 | struct lm77_data *data = i2c_get_clientdata(client); | |
398 | ||
9a61bf63 | 399 | mutex_lock(&data->update_lock); |
1da177e4 LT |
400 | |
401 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
402 | || !data->valid) { | |
403 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
404 | data->temp_input = | |
405 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
406 | LM77_REG_TEMP)); | |
407 | data->temp_hyst = | |
408 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
409 | LM77_REG_TEMP_HYST)); | |
410 | data->temp_crit = | |
411 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
412 | LM77_REG_TEMP_CRIT)); | |
413 | data->temp_min = | |
414 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
415 | LM77_REG_TEMP_MIN)); | |
416 | data->temp_max = | |
417 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
418 | LM77_REG_TEMP_MAX)); | |
419 | data->alarms = | |
420 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
421 | data->last_updated = jiffies; | |
422 | data->valid = 1; | |
423 | } | |
424 | ||
9a61bf63 | 425 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
426 | |
427 | return data; | |
428 | } | |
429 | ||
430 | static int __init sensors_lm77_init(void) | |
431 | { | |
432 | return i2c_add_driver(&lm77_driver); | |
433 | } | |
434 | ||
435 | static void __exit sensors_lm77_exit(void) | |
436 | { | |
437 | i2c_del_driver(&lm77_driver); | |
438 | } | |
439 | ||
440 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
441 | MODULE_DESCRIPTION("LM77 driver"); | |
442 | MODULE_LICENSE("GPL"); | |
443 | ||
444 | module_init(sensors_lm77_init); | |
445 | module_exit(sensors_lm77_exit); |