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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 | 41 | |
1da177e4 LT |
42 | /* The LM77 registers */ |
43 | #define LM77_REG_TEMP 0x00 | |
44 | #define LM77_REG_CONF 0x01 | |
45 | #define LM77_REG_TEMP_HYST 0x02 | |
46 | #define LM77_REG_TEMP_CRIT 0x03 | |
47 | #define LM77_REG_TEMP_MIN 0x04 | |
48 | #define LM77_REG_TEMP_MAX 0x05 | |
49 | ||
50 | /* Each client has this additional data */ | |
51 | struct lm77_data { | |
1beeffe4 | 52 | struct device *hwmon_dev; |
9a61bf63 | 53 | struct mutex update_lock; |
1da177e4 LT |
54 | char valid; |
55 | unsigned long last_updated; /* In jiffies */ | |
56 | int temp_input; /* Temperatures */ | |
57 | int temp_crit; | |
58 | int temp_min; | |
59 | int temp_max; | |
60 | int temp_hyst; | |
61 | u8 alarms; | |
62 | }; | |
63 | ||
a189dd62 JD |
64 | static int lm77_probe(struct i2c_client *client, |
65 | const struct i2c_device_id *id); | |
310ec792 | 66 | static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info); |
1da177e4 | 67 | static void lm77_init_client(struct i2c_client *client); |
a189dd62 | 68 | static int lm77_remove(struct i2c_client *client); |
1da177e4 LT |
69 | static u16 lm77_read_value(struct i2c_client *client, u8 reg); |
70 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value); | |
71 | ||
72 | static struct lm77_data *lm77_update_device(struct device *dev); | |
73 | ||
74 | ||
a189dd62 | 75 | static const struct i2c_device_id lm77_id[] = { |
1f86df49 | 76 | { "lm77", 0 }, |
a189dd62 JD |
77 | { } |
78 | }; | |
79 | MODULE_DEVICE_TABLE(i2c, lm77_id); | |
80 | ||
1da177e4 LT |
81 | /* This is the driver that will be inserted */ |
82 | static struct i2c_driver lm77_driver = { | |
a189dd62 | 83 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 84 | .driver = { |
cdaf7934 LR |
85 | .name = "lm77", |
86 | }, | |
a189dd62 JD |
87 | .probe = lm77_probe, |
88 | .remove = lm77_remove, | |
89 | .id_table = lm77_id, | |
90 | .detect = lm77_detect, | |
c3813d6a | 91 | .address_list = normal_i2c, |
1da177e4 LT |
92 | }; |
93 | ||
94 | /* straight from the datasheet */ | |
95 | #define LM77_TEMP_MIN (-55000) | |
96 | #define LM77_TEMP_MAX 125000 | |
97 | ||
98 | /* In the temperature registers, the low 3 bits are not part of the | |
99 | temperature values; they are the status bits. */ | |
413b6451 | 100 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 LT |
101 | { |
102 | int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); | |
413b6451 | 103 | return (ntemp / 500) * 8; |
1da177e4 LT |
104 | } |
105 | ||
413b6451 | 106 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 107 | { |
413b6451 | 108 | return (reg / 8) * 500; |
1da177e4 LT |
109 | } |
110 | ||
111 | /* sysfs stuff */ | |
112 | ||
113 | /* read routines for temperature limits */ | |
114 | #define show(value) \ | |
8627f9ba | 115 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
116 | { \ |
117 | struct lm77_data *data = lm77_update_device(dev); \ | |
118 | return sprintf(buf, "%d\n", data->value); \ | |
119 | } | |
120 | ||
121 | show(temp_input); | |
122 | show(temp_crit); | |
123 | show(temp_min); | |
124 | show(temp_max); | |
1da177e4 LT |
125 | |
126 | /* read routines for hysteresis values */ | |
8627f9ba | 127 | static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
128 | { |
129 | struct lm77_data *data = lm77_update_device(dev); | |
130 | return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); | |
131 | } | |
8627f9ba | 132 | static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
133 | { |
134 | struct lm77_data *data = lm77_update_device(dev); | |
135 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
136 | } | |
8627f9ba | 137 | static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
138 | { |
139 | struct lm77_data *data = lm77_update_device(dev); | |
140 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
141 | } | |
142 | ||
143 | /* write routines */ | |
144 | #define set(value, reg) \ | |
8627f9ba | 145 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \ |
1da177e4 LT |
146 | { \ |
147 | struct i2c_client *client = to_i2c_client(dev); \ | |
148 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
5bfedac0 | 149 | long val = simple_strtol(buf, NULL, 10); \ |
1da177e4 | 150 | \ |
9a61bf63 | 151 | mutex_lock(&data->update_lock); \ |
1da177e4 LT |
152 | data->value = val; \ |
153 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
9a61bf63 | 154 | mutex_unlock(&data->update_lock); \ |
1da177e4 LT |
155 | return count; \ |
156 | } | |
157 | ||
158 | set(temp_min, LM77_REG_TEMP_MIN); | |
159 | set(temp_max, LM77_REG_TEMP_MAX); | |
160 | ||
161 | /* hysteresis is stored as a relative value on the chip, so it has to be | |
162 | converted first */ | |
8627f9ba | 163 | static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
164 | { |
165 | struct i2c_client *client = to_i2c_client(dev); | |
166 | struct lm77_data *data = i2c_get_clientdata(client); | |
167 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
168 | ||
9a61bf63 | 169 | mutex_lock(&data->update_lock); |
1da177e4 LT |
170 | data->temp_hyst = data->temp_crit - val; |
171 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
172 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 173 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
174 | return count; |
175 | } | |
176 | ||
177 | /* preserve hysteresis when setting T_crit */ | |
8627f9ba | 178 | static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
179 | { |
180 | struct i2c_client *client = to_i2c_client(dev); | |
181 | struct lm77_data *data = i2c_get_clientdata(client); | |
182 | long val = simple_strtoul(buf, NULL, 10); | |
183 | int oldcrithyst; | |
184 | ||
9a61bf63 | 185 | mutex_lock(&data->update_lock); |
1da177e4 LT |
186 | oldcrithyst = data->temp_crit - data->temp_hyst; |
187 | data->temp_crit = val; | |
188 | data->temp_hyst = data->temp_crit - oldcrithyst; | |
189 | lm77_write_value(client, LM77_REG_TEMP_CRIT, | |
190 | LM77_TEMP_TO_REG(data->temp_crit)); | |
191 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
192 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 193 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
194 | return count; |
195 | } | |
196 | ||
1f52af0f JD |
197 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
198 | char *buf) | |
199 | { | |
200 | int bitnr = to_sensor_dev_attr(attr)->index; | |
201 | struct lm77_data *data = lm77_update_device(dev); | |
202 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
203 | } | |
204 | ||
1da177e4 LT |
205 | static DEVICE_ATTR(temp1_input, S_IRUGO, |
206 | show_temp_input, NULL); | |
207 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
208 | show_temp_crit, set_temp_crit); | |
209 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
210 | show_temp_min, set_temp_min); | |
211 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
212 | show_temp_max, set_temp_max); | |
213 | ||
214 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
215 | show_temp_crit_hyst, set_temp_crit_hyst); | |
216 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
217 | show_temp_min_hyst, NULL); | |
218 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
219 | show_temp_max_hyst, NULL); | |
220 | ||
1f52af0f JD |
221 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
222 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
223 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 | 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 | ||
a189dd62 | 243 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 244 | static int lm77_detect(struct i2c_client *new_client, |
a189dd62 | 245 | struct i2c_board_info *info) |
1da177e4 | 246 | { |
a189dd62 | 247 | struct i2c_adapter *adapter = new_client->adapter; |
747d9bed | 248 | int i, cur, conf, hyst, crit, min, max; |
1da177e4 LT |
249 | |
250 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
251 | I2C_FUNC_SMBUS_WORD_DATA)) | |
a189dd62 | 252 | return -ENODEV; |
1da177e4 LT |
253 | |
254 | /* Here comes the remaining detection. Since the LM77 has no | |
255 | register dedicated to identification, we have to rely on the | |
256 | following tricks: | |
257 | ||
258 | 1. the high 4 bits represent the sign and thus they should | |
259 | always be the same | |
260 | 2. the high 3 bits are unused in the configuration register | |
261 | 3. addresses 0x06 and 0x07 return the last read value | |
262 | 4. registers cycling over 8-address boundaries | |
263 | ||
264 | Word-sized registers are high-byte first. */ | |
1da177e4 | 265 | |
747d9bed JD |
266 | /* addresses cycling */ |
267 | cur = i2c_smbus_read_word_data(new_client, 0); | |
268 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
269 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
270 | crit = i2c_smbus_read_word_data(new_client, 3); | |
271 | min = i2c_smbus_read_word_data(new_client, 4); | |
272 | max = i2c_smbus_read_word_data(new_client, 5); | |
273 | for (i = 8; i <= 0xff; i += 8) { | |
274 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
275 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
276 | || i2c_smbus_read_word_data(new_client, i + 3) != crit | |
277 | || i2c_smbus_read_word_data(new_client, i + 4) != min | |
278 | || i2c_smbus_read_word_data(new_client, i + 5) != max) | |
a189dd62 | 279 | return -ENODEV; |
747d9bed | 280 | } |
1da177e4 | 281 | |
747d9bed JD |
282 | /* sign bits */ |
283 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
284 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
285 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
286 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
287 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
288 | return -ENODEV; | |
1da177e4 | 289 | |
747d9bed JD |
290 | /* unused bits */ |
291 | if (conf & 0xe0) | |
292 | return -ENODEV; | |
293 | ||
294 | /* 0x06 and 0x07 return the last read value */ | |
295 | cur = i2c_smbus_read_word_data(new_client, 0); | |
296 | if (i2c_smbus_read_word_data(new_client, 6) != cur | |
297 | || i2c_smbus_read_word_data(new_client, 7) != cur) | |
298 | return -ENODEV; | |
299 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
300 | if (i2c_smbus_read_word_data(new_client, 6) != hyst | |
301 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
302 | return -ENODEV; | |
303 | min = i2c_smbus_read_word_data(new_client, 4); | |
304 | if (i2c_smbus_read_word_data(new_client, 6) != min | |
305 | || i2c_smbus_read_word_data(new_client, 7) != min) | |
306 | return -ENODEV; | |
1da177e4 | 307 | |
a189dd62 | 308 | strlcpy(info->type, "lm77", I2C_NAME_SIZE); |
1da177e4 | 309 | |
a189dd62 JD |
310 | return 0; |
311 | } | |
312 | ||
313 | static int lm77_probe(struct i2c_client *new_client, | |
314 | const struct i2c_device_id *id) | |
315 | { | |
316 | struct lm77_data *data; | |
317 | int err; | |
318 | ||
319 | data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL); | |
320 | if (!data) { | |
321 | err = -ENOMEM; | |
322 | goto exit; | |
1da177e4 LT |
323 | } |
324 | ||
a189dd62 | 325 | i2c_set_clientdata(new_client, data); |
1da177e4 | 326 | data->valid = 0; |
9a61bf63 | 327 | mutex_init(&data->update_lock); |
1da177e4 | 328 | |
1da177e4 LT |
329 | /* Initialize the LM77 chip */ |
330 | lm77_init_client(new_client); | |
331 | ||
332 | /* Register sysfs hooks */ | |
0501a381 | 333 | if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group))) |
a189dd62 | 334 | goto exit_free; |
0501a381 | 335 | |
1beeffe4 TJ |
336 | data->hwmon_dev = hwmon_device_register(&new_client->dev); |
337 | if (IS_ERR(data->hwmon_dev)) { | |
338 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 339 | goto exit_remove; |
943b0830 MH |
340 | } |
341 | ||
1da177e4 LT |
342 | return 0; |
343 | ||
0501a381 MH |
344 | exit_remove: |
345 | sysfs_remove_group(&new_client->dev.kobj, &lm77_group); | |
1da177e4 LT |
346 | exit_free: |
347 | kfree(data); | |
348 | exit: | |
349 | return err; | |
350 | } | |
351 | ||
a189dd62 | 352 | static int lm77_remove(struct i2c_client *client) |
1da177e4 | 353 | { |
943b0830 | 354 | struct lm77_data *data = i2c_get_clientdata(client); |
1beeffe4 | 355 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 356 | sysfs_remove_group(&client->dev.kobj, &lm77_group); |
943b0830 | 357 | kfree(data); |
1da177e4 LT |
358 | return 0; |
359 | } | |
360 | ||
361 | /* All registers are word-sized, except for the configuration register. | |
362 | The LM77 uses the high-byte first convention. */ | |
363 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
364 | { | |
365 | if (reg == LM77_REG_CONF) | |
366 | return i2c_smbus_read_byte_data(client, reg); | |
367 | else | |
368 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
369 | } | |
370 | ||
371 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
372 | { | |
373 | if (reg == LM77_REG_CONF) | |
374 | return i2c_smbus_write_byte_data(client, reg, value); | |
375 | else | |
376 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
377 | } | |
378 | ||
379 | static void lm77_init_client(struct i2c_client *client) | |
380 | { | |
381 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
382 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
383 | if (conf & 1) | |
384 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
385 | } | |
386 | ||
387 | static struct lm77_data *lm77_update_device(struct device *dev) | |
388 | { | |
389 | struct i2c_client *client = to_i2c_client(dev); | |
390 | struct lm77_data *data = i2c_get_clientdata(client); | |
391 | ||
9a61bf63 | 392 | mutex_lock(&data->update_lock); |
1da177e4 LT |
393 | |
394 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
395 | || !data->valid) { | |
396 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
397 | data->temp_input = | |
398 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
399 | LM77_REG_TEMP)); | |
400 | data->temp_hyst = | |
401 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
402 | LM77_REG_TEMP_HYST)); | |
403 | data->temp_crit = | |
404 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
405 | LM77_REG_TEMP_CRIT)); | |
406 | data->temp_min = | |
407 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
408 | LM77_REG_TEMP_MIN)); | |
409 | data->temp_max = | |
410 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
411 | LM77_REG_TEMP_MAX)); | |
412 | data->alarms = | |
413 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
414 | data->last_updated = jiffies; | |
415 | data->valid = 1; | |
416 | } | |
417 | ||
9a61bf63 | 418 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
419 | |
420 | return data; | |
421 | } | |
422 | ||
423 | static int __init sensors_lm77_init(void) | |
424 | { | |
425 | return i2c_add_driver(&lm77_driver); | |
426 | } | |
427 | ||
428 | static void __exit sensors_lm77_exit(void) | |
429 | { | |
430 | i2c_del_driver(&lm77_driver); | |
431 | } | |
432 | ||
433 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
434 | MODULE_DESCRIPTION("LM77 driver"); | |
435 | MODULE_LICENSE("GPL"); | |
436 | ||
437 | module_init(sensors_lm77_init); | |
438 | module_exit(sensors_lm77_exit); |