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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 | 33 | #include <linux/hwmon.h> |
1f52af0f | 34 | #include <linux/hwmon-sysfs.h> |
943b0830 | 35 | #include <linux/err.h> |
9a61bf63 | 36 | #include <linux/mutex.h> |
1da177e4 LT |
37 | |
38 | /* Addresses to scan */ | |
25e9c86d MH |
39 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
40 | I2C_CLIENT_END }; | |
1da177e4 LT |
41 | |
42 | /* Insmod parameters */ | |
f4b50261 | 43 | I2C_CLIENT_INSMOD_1(lm77); |
1da177e4 LT |
44 | |
45 | /* The LM77 registers */ | |
46 | #define LM77_REG_TEMP 0x00 | |
47 | #define LM77_REG_CONF 0x01 | |
48 | #define LM77_REG_TEMP_HYST 0x02 | |
49 | #define LM77_REG_TEMP_CRIT 0x03 | |
50 | #define LM77_REG_TEMP_MIN 0x04 | |
51 | #define LM77_REG_TEMP_MAX 0x05 | |
52 | ||
53 | /* Each client has this additional data */ | |
54 | struct lm77_data { | |
55 | struct i2c_client client; | |
1beeffe4 | 56 | struct device *hwmon_dev; |
9a61bf63 | 57 | struct mutex update_lock; |
1da177e4 LT |
58 | char valid; |
59 | unsigned long last_updated; /* In jiffies */ | |
60 | int temp_input; /* Temperatures */ | |
61 | int temp_crit; | |
62 | int temp_min; | |
63 | int temp_max; | |
64 | int temp_hyst; | |
65 | u8 alarms; | |
66 | }; | |
67 | ||
68 | static int lm77_attach_adapter(struct i2c_adapter *adapter); | |
69 | static int lm77_detect(struct i2c_adapter *adapter, int address, int kind); | |
70 | static void lm77_init_client(struct i2c_client *client); | |
71 | static int lm77_detach_client(struct i2c_client *client); | |
72 | static u16 lm77_read_value(struct i2c_client *client, u8 reg); | |
73 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value); | |
74 | ||
75 | static struct lm77_data *lm77_update_device(struct device *dev); | |
76 | ||
77 | ||
78 | /* This is the driver that will be inserted */ | |
79 | static struct i2c_driver lm77_driver = { | |
cdaf7934 | 80 | .driver = { |
cdaf7934 LR |
81 | .name = "lm77", |
82 | }, | |
1da177e4 LT |
83 | .attach_adapter = lm77_attach_adapter, |
84 | .detach_client = lm77_detach_client, | |
85 | }; | |
86 | ||
87 | /* straight from the datasheet */ | |
88 | #define LM77_TEMP_MIN (-55000) | |
89 | #define LM77_TEMP_MAX 125000 | |
90 | ||
91 | /* In the temperature registers, the low 3 bits are not part of the | |
92 | temperature values; they are the status bits. */ | |
413b6451 | 93 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 LT |
94 | { |
95 | int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); | |
413b6451 | 96 | return (ntemp / 500) * 8; |
1da177e4 LT |
97 | } |
98 | ||
413b6451 | 99 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 100 | { |
413b6451 | 101 | return (reg / 8) * 500; |
1da177e4 LT |
102 | } |
103 | ||
104 | /* sysfs stuff */ | |
105 | ||
106 | /* read routines for temperature limits */ | |
107 | #define show(value) \ | |
8627f9ba | 108 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
109 | { \ |
110 | struct lm77_data *data = lm77_update_device(dev); \ | |
111 | return sprintf(buf, "%d\n", data->value); \ | |
112 | } | |
113 | ||
114 | show(temp_input); | |
115 | show(temp_crit); | |
116 | show(temp_min); | |
117 | show(temp_max); | |
1da177e4 LT |
118 | |
119 | /* read routines for hysteresis values */ | |
8627f9ba | 120 | static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
121 | { |
122 | struct lm77_data *data = lm77_update_device(dev); | |
123 | return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); | |
124 | } | |
8627f9ba | 125 | static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
126 | { |
127 | struct lm77_data *data = lm77_update_device(dev); | |
128 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
129 | } | |
8627f9ba | 130 | static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
131 | { |
132 | struct lm77_data *data = lm77_update_device(dev); | |
133 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
134 | } | |
135 | ||
136 | /* write routines */ | |
137 | #define set(value, reg) \ | |
8627f9ba | 138 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \ |
1da177e4 LT |
139 | { \ |
140 | struct i2c_client *client = to_i2c_client(dev); \ | |
141 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
5bfedac0 | 142 | long val = simple_strtol(buf, NULL, 10); \ |
1da177e4 | 143 | \ |
9a61bf63 | 144 | mutex_lock(&data->update_lock); \ |
1da177e4 LT |
145 | data->value = val; \ |
146 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
9a61bf63 | 147 | mutex_unlock(&data->update_lock); \ |
1da177e4 LT |
148 | return count; \ |
149 | } | |
150 | ||
151 | set(temp_min, LM77_REG_TEMP_MIN); | |
152 | set(temp_max, LM77_REG_TEMP_MAX); | |
153 | ||
154 | /* hysteresis is stored as a relative value on the chip, so it has to be | |
155 | converted first */ | |
8627f9ba | 156 | static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
157 | { |
158 | struct i2c_client *client = to_i2c_client(dev); | |
159 | struct lm77_data *data = i2c_get_clientdata(client); | |
160 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
161 | ||
9a61bf63 | 162 | mutex_lock(&data->update_lock); |
1da177e4 LT |
163 | data->temp_hyst = data->temp_crit - val; |
164 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
165 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 166 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
167 | return count; |
168 | } | |
169 | ||
170 | /* preserve hysteresis when setting T_crit */ | |
8627f9ba | 171 | static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
172 | { |
173 | struct i2c_client *client = to_i2c_client(dev); | |
174 | struct lm77_data *data = i2c_get_clientdata(client); | |
175 | long val = simple_strtoul(buf, NULL, 10); | |
176 | int oldcrithyst; | |
177 | ||
9a61bf63 | 178 | mutex_lock(&data->update_lock); |
1da177e4 LT |
179 | oldcrithyst = data->temp_crit - data->temp_hyst; |
180 | data->temp_crit = val; | |
181 | data->temp_hyst = data->temp_crit - oldcrithyst; | |
182 | lm77_write_value(client, LM77_REG_TEMP_CRIT, | |
183 | LM77_TEMP_TO_REG(data->temp_crit)); | |
184 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
185 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 186 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
187 | return count; |
188 | } | |
189 | ||
1f52af0f JD |
190 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
191 | char *buf) | |
192 | { | |
193 | int bitnr = to_sensor_dev_attr(attr)->index; | |
194 | struct lm77_data *data = lm77_update_device(dev); | |
195 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
196 | } | |
197 | ||
1da177e4 LT |
198 | static DEVICE_ATTR(temp1_input, S_IRUGO, |
199 | show_temp_input, NULL); | |
200 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
201 | show_temp_crit, set_temp_crit); | |
202 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
203 | show_temp_min, set_temp_min); | |
204 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
205 | show_temp_max, set_temp_max); | |
206 | ||
207 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
208 | show_temp_crit_hyst, set_temp_crit_hyst); | |
209 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
210 | show_temp_min_hyst, NULL); | |
211 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
212 | show_temp_max_hyst, NULL); | |
213 | ||
1f52af0f JD |
214 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
215 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
216 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 LT |
217 | |
218 | static int lm77_attach_adapter(struct i2c_adapter *adapter) | |
219 | { | |
220 | if (!(adapter->class & I2C_CLASS_HWMON)) | |
221 | return 0; | |
2ed2dc3c | 222 | return i2c_probe(adapter, &addr_data, lm77_detect); |
1da177e4 LT |
223 | } |
224 | ||
0501a381 MH |
225 | static struct attribute *lm77_attributes[] = { |
226 | &dev_attr_temp1_input.attr, | |
227 | &dev_attr_temp1_crit.attr, | |
228 | &dev_attr_temp1_min.attr, | |
229 | &dev_attr_temp1_max.attr, | |
230 | &dev_attr_temp1_crit_hyst.attr, | |
231 | &dev_attr_temp1_min_hyst.attr, | |
232 | &dev_attr_temp1_max_hyst.attr, | |
1f52af0f JD |
233 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
234 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
235 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
236 | NULL |
237 | }; | |
238 | ||
239 | static const struct attribute_group lm77_group = { | |
240 | .attrs = lm77_attributes, | |
241 | }; | |
242 | ||
2ed2dc3c | 243 | /* This function is called by i2c_probe */ |
1da177e4 LT |
244 | static int lm77_detect(struct i2c_adapter *adapter, int address, int kind) |
245 | { | |
246 | struct i2c_client *new_client; | |
247 | struct lm77_data *data; | |
248 | int err = 0; | |
249 | const char *name = ""; | |
250 | ||
251 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
252 | I2C_FUNC_SMBUS_WORD_DATA)) | |
253 | goto exit; | |
254 | ||
255 | /* OK. For now, we presume we have a valid client. We now create the | |
256 | client structure, even though we cannot fill it completely yet. | |
257 | But it allows us to access lm77_{read,write}_value. */ | |
ba9c2e8d | 258 | if (!(data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL))) { |
1da177e4 LT |
259 | err = -ENOMEM; |
260 | goto exit; | |
261 | } | |
1da177e4 LT |
262 | |
263 | new_client = &data->client; | |
264 | i2c_set_clientdata(new_client, data); | |
265 | new_client->addr = address; | |
266 | new_client->adapter = adapter; | |
267 | new_client->driver = &lm77_driver; | |
268 | new_client->flags = 0; | |
269 | ||
270 | /* Here comes the remaining detection. Since the LM77 has no | |
271 | register dedicated to identification, we have to rely on the | |
272 | following tricks: | |
273 | ||
274 | 1. the high 4 bits represent the sign and thus they should | |
275 | always be the same | |
276 | 2. the high 3 bits are unused in the configuration register | |
277 | 3. addresses 0x06 and 0x07 return the last read value | |
278 | 4. registers cycling over 8-address boundaries | |
279 | ||
280 | Word-sized registers are high-byte first. */ | |
281 | if (kind < 0) { | |
282 | int i, cur, conf, hyst, crit, min, max; | |
283 | ||
284 | /* addresses cycling */ | |
285 | cur = i2c_smbus_read_word_data(new_client, 0); | |
286 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
287 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
288 | crit = i2c_smbus_read_word_data(new_client, 3); | |
289 | min = i2c_smbus_read_word_data(new_client, 4); | |
290 | max = i2c_smbus_read_word_data(new_client, 5); | |
291 | for (i = 8; i <= 0xff; i += 8) | |
292 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
293 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
294 | || i2c_smbus_read_word_data(new_client, i + 3) != crit | |
295 | || i2c_smbus_read_word_data(new_client, i + 4) != min | |
296 | || i2c_smbus_read_word_data(new_client, i + 5) != max) | |
297 | goto exit_free; | |
298 | ||
299 | /* sign bits */ | |
300 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
301 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
302 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
303 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
304 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
305 | goto exit_free; | |
306 | ||
307 | /* unused bits */ | |
308 | if (conf & 0xe0) | |
309 | goto exit_free; | |
310 | ||
311 | /* 0x06 and 0x07 return the last read value */ | |
312 | cur = i2c_smbus_read_word_data(new_client, 0); | |
313 | if (i2c_smbus_read_word_data(new_client, 6) != cur | |
314 | || i2c_smbus_read_word_data(new_client, 7) != cur) | |
315 | goto exit_free; | |
316 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
317 | if (i2c_smbus_read_word_data(new_client, 6) != hyst | |
318 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
319 | goto exit_free; | |
320 | min = i2c_smbus_read_word_data(new_client, 4); | |
321 | if (i2c_smbus_read_word_data(new_client, 6) != min | |
322 | || i2c_smbus_read_word_data(new_client, 7) != min) | |
323 | goto exit_free; | |
324 | ||
325 | } | |
326 | ||
327 | /* Determine the chip type - only one kind supported! */ | |
328 | if (kind <= 0) | |
329 | kind = lm77; | |
330 | ||
331 | if (kind == lm77) { | |
332 | name = "lm77"; | |
333 | } | |
334 | ||
335 | /* Fill in the remaining client fields and put it into the global list */ | |
336 | strlcpy(new_client->name, name, I2C_NAME_SIZE); | |
337 | data->valid = 0; | |
9a61bf63 | 338 | mutex_init(&data->update_lock); |
1da177e4 LT |
339 | |
340 | /* Tell the I2C layer a new client has arrived */ | |
341 | if ((err = i2c_attach_client(new_client))) | |
342 | goto exit_free; | |
343 | ||
344 | /* Initialize the LM77 chip */ | |
345 | lm77_init_client(new_client); | |
346 | ||
347 | /* Register sysfs hooks */ | |
0501a381 MH |
348 | if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group))) |
349 | goto exit_detach; | |
350 | ||
1beeffe4 TJ |
351 | data->hwmon_dev = hwmon_device_register(&new_client->dev); |
352 | if (IS_ERR(data->hwmon_dev)) { | |
353 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 354 | goto exit_remove; |
943b0830 MH |
355 | } |
356 | ||
1da177e4 LT |
357 | return 0; |
358 | ||
0501a381 MH |
359 | exit_remove: |
360 | sysfs_remove_group(&new_client->dev.kobj, &lm77_group); | |
943b0830 MH |
361 | exit_detach: |
362 | i2c_detach_client(new_client); | |
1da177e4 LT |
363 | exit_free: |
364 | kfree(data); | |
365 | exit: | |
366 | return err; | |
367 | } | |
368 | ||
369 | static int lm77_detach_client(struct i2c_client *client) | |
370 | { | |
943b0830 | 371 | struct lm77_data *data = i2c_get_clientdata(client); |
1beeffe4 | 372 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 373 | sysfs_remove_group(&client->dev.kobj, &lm77_group); |
1da177e4 | 374 | i2c_detach_client(client); |
943b0830 | 375 | kfree(data); |
1da177e4 LT |
376 | return 0; |
377 | } | |
378 | ||
379 | /* All registers are word-sized, except for the configuration register. | |
380 | The LM77 uses the high-byte first convention. */ | |
381 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
382 | { | |
383 | if (reg == LM77_REG_CONF) | |
384 | return i2c_smbus_read_byte_data(client, reg); | |
385 | else | |
386 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
387 | } | |
388 | ||
389 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
390 | { | |
391 | if (reg == LM77_REG_CONF) | |
392 | return i2c_smbus_write_byte_data(client, reg, value); | |
393 | else | |
394 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
395 | } | |
396 | ||
397 | static void lm77_init_client(struct i2c_client *client) | |
398 | { | |
399 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
400 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
401 | if (conf & 1) | |
402 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
403 | } | |
404 | ||
405 | static struct lm77_data *lm77_update_device(struct device *dev) | |
406 | { | |
407 | struct i2c_client *client = to_i2c_client(dev); | |
408 | struct lm77_data *data = i2c_get_clientdata(client); | |
409 | ||
9a61bf63 | 410 | mutex_lock(&data->update_lock); |
1da177e4 LT |
411 | |
412 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
413 | || !data->valid) { | |
414 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
415 | data->temp_input = | |
416 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
417 | LM77_REG_TEMP)); | |
418 | data->temp_hyst = | |
419 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
420 | LM77_REG_TEMP_HYST)); | |
421 | data->temp_crit = | |
422 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
423 | LM77_REG_TEMP_CRIT)); | |
424 | data->temp_min = | |
425 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
426 | LM77_REG_TEMP_MIN)); | |
427 | data->temp_max = | |
428 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
429 | LM77_REG_TEMP_MAX)); | |
430 | data->alarms = | |
431 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
432 | data->last_updated = jiffies; | |
433 | data->valid = 1; | |
434 | } | |
435 | ||
9a61bf63 | 436 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
437 | |
438 | return data; | |
439 | } | |
440 | ||
441 | static int __init sensors_lm77_init(void) | |
442 | { | |
443 | return i2c_add_driver(&lm77_driver); | |
444 | } | |
445 | ||
446 | static void __exit sensors_lm77_exit(void) | |
447 | { | |
448 | i2c_del_driver(&lm77_driver); | |
449 | } | |
450 | ||
451 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
452 | MODULE_DESCRIPTION("LM77 driver"); | |
453 | MODULE_LICENSE("GPL"); | |
454 | ||
455 | module_init(sensors_lm77_init); | |
456 | module_exit(sensors_lm77_exit); |