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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 { | |
1beeffe4 | 55 | struct device *hwmon_dev; |
9a61bf63 | 56 | struct mutex update_lock; |
1da177e4 LT |
57 | char valid; |
58 | unsigned long last_updated; /* In jiffies */ | |
59 | int temp_input; /* Temperatures */ | |
60 | int temp_crit; | |
61 | int temp_min; | |
62 | int temp_max; | |
63 | int temp_hyst; | |
64 | u8 alarms; | |
65 | }; | |
66 | ||
a189dd62 JD |
67 | static int lm77_probe(struct i2c_client *client, |
68 | const struct i2c_device_id *id); | |
310ec792 | 69 | static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info); |
1da177e4 | 70 | static void lm77_init_client(struct i2c_client *client); |
a189dd62 | 71 | static int lm77_remove(struct i2c_client *client); |
1da177e4 LT |
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 | ||
a189dd62 JD |
78 | static const struct i2c_device_id lm77_id[] = { |
79 | { "lm77", lm77 }, | |
80 | { } | |
81 | }; | |
82 | MODULE_DEVICE_TABLE(i2c, lm77_id); | |
83 | ||
1da177e4 LT |
84 | /* This is the driver that will be inserted */ |
85 | static struct i2c_driver lm77_driver = { | |
a189dd62 | 86 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 87 | .driver = { |
cdaf7934 LR |
88 | .name = "lm77", |
89 | }, | |
a189dd62 JD |
90 | .probe = lm77_probe, |
91 | .remove = lm77_remove, | |
92 | .id_table = lm77_id, | |
93 | .detect = lm77_detect, | |
94 | .address_data = &addr_data, | |
1da177e4 LT |
95 | }; |
96 | ||
97 | /* straight from the datasheet */ | |
98 | #define LM77_TEMP_MIN (-55000) | |
99 | #define LM77_TEMP_MAX 125000 | |
100 | ||
101 | /* In the temperature registers, the low 3 bits are not part of the | |
102 | temperature values; they are the status bits. */ | |
413b6451 | 103 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 LT |
104 | { |
105 | int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); | |
413b6451 | 106 | return (ntemp / 500) * 8; |
1da177e4 LT |
107 | } |
108 | ||
413b6451 | 109 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 110 | { |
413b6451 | 111 | return (reg / 8) * 500; |
1da177e4 LT |
112 | } |
113 | ||
114 | /* sysfs stuff */ | |
115 | ||
116 | /* read routines for temperature limits */ | |
117 | #define show(value) \ | |
8627f9ba | 118 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
119 | { \ |
120 | struct lm77_data *data = lm77_update_device(dev); \ | |
121 | return sprintf(buf, "%d\n", data->value); \ | |
122 | } | |
123 | ||
124 | show(temp_input); | |
125 | show(temp_crit); | |
126 | show(temp_min); | |
127 | show(temp_max); | |
1da177e4 LT |
128 | |
129 | /* read routines for hysteresis values */ | |
8627f9ba | 130 | static ssize_t show_temp_crit_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_crit - data->temp_hyst); | |
134 | } | |
8627f9ba | 135 | static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
136 | { |
137 | struct lm77_data *data = lm77_update_device(dev); | |
138 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
139 | } | |
8627f9ba | 140 | static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
141 | { |
142 | struct lm77_data *data = lm77_update_device(dev); | |
143 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
144 | } | |
145 | ||
146 | /* write routines */ | |
147 | #define set(value, reg) \ | |
8627f9ba | 148 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \ |
1da177e4 LT |
149 | { \ |
150 | struct i2c_client *client = to_i2c_client(dev); \ | |
151 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
5bfedac0 | 152 | long val = simple_strtol(buf, NULL, 10); \ |
1da177e4 | 153 | \ |
9a61bf63 | 154 | mutex_lock(&data->update_lock); \ |
1da177e4 LT |
155 | data->value = val; \ |
156 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
9a61bf63 | 157 | mutex_unlock(&data->update_lock); \ |
1da177e4 LT |
158 | return count; \ |
159 | } | |
160 | ||
161 | set(temp_min, LM77_REG_TEMP_MIN); | |
162 | set(temp_max, LM77_REG_TEMP_MAX); | |
163 | ||
164 | /* hysteresis is stored as a relative value on the chip, so it has to be | |
165 | converted first */ | |
8627f9ba | 166 | static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
167 | { |
168 | struct i2c_client *client = to_i2c_client(dev); | |
169 | struct lm77_data *data = i2c_get_clientdata(client); | |
170 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
171 | ||
9a61bf63 | 172 | mutex_lock(&data->update_lock); |
1da177e4 LT |
173 | data->temp_hyst = data->temp_crit - val; |
174 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
175 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 176 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
177 | return count; |
178 | } | |
179 | ||
180 | /* preserve hysteresis when setting T_crit */ | |
8627f9ba | 181 | static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
182 | { |
183 | struct i2c_client *client = to_i2c_client(dev); | |
184 | struct lm77_data *data = i2c_get_clientdata(client); | |
185 | long val = simple_strtoul(buf, NULL, 10); | |
186 | int oldcrithyst; | |
187 | ||
9a61bf63 | 188 | mutex_lock(&data->update_lock); |
1da177e4 LT |
189 | oldcrithyst = data->temp_crit - data->temp_hyst; |
190 | data->temp_crit = val; | |
191 | data->temp_hyst = data->temp_crit - oldcrithyst; | |
192 | lm77_write_value(client, LM77_REG_TEMP_CRIT, | |
193 | LM77_TEMP_TO_REG(data->temp_crit)); | |
194 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
195 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 196 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
197 | return count; |
198 | } | |
199 | ||
1f52af0f JD |
200 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
201 | char *buf) | |
202 | { | |
203 | int bitnr = to_sensor_dev_attr(attr)->index; | |
204 | struct lm77_data *data = lm77_update_device(dev); | |
205 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
206 | } | |
207 | ||
1da177e4 LT |
208 | static DEVICE_ATTR(temp1_input, S_IRUGO, |
209 | show_temp_input, NULL); | |
210 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
211 | show_temp_crit, set_temp_crit); | |
212 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
213 | show_temp_min, set_temp_min); | |
214 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
215 | show_temp_max, set_temp_max); | |
216 | ||
217 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
218 | show_temp_crit_hyst, set_temp_crit_hyst); | |
219 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
220 | show_temp_min_hyst, NULL); | |
221 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
222 | show_temp_max_hyst, NULL); | |
223 | ||
1f52af0f JD |
224 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
225 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
226 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 | 227 | |
0501a381 MH |
228 | static struct attribute *lm77_attributes[] = { |
229 | &dev_attr_temp1_input.attr, | |
230 | &dev_attr_temp1_crit.attr, | |
231 | &dev_attr_temp1_min.attr, | |
232 | &dev_attr_temp1_max.attr, | |
233 | &dev_attr_temp1_crit_hyst.attr, | |
234 | &dev_attr_temp1_min_hyst.attr, | |
235 | &dev_attr_temp1_max_hyst.attr, | |
1f52af0f JD |
236 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
237 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
238 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
239 | NULL |
240 | }; | |
241 | ||
242 | static const struct attribute_group lm77_group = { | |
243 | .attrs = lm77_attributes, | |
244 | }; | |
245 | ||
a189dd62 | 246 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 247 | static int lm77_detect(struct i2c_client *new_client, |
a189dd62 | 248 | struct i2c_board_info *info) |
1da177e4 | 249 | { |
a189dd62 | 250 | struct i2c_adapter *adapter = new_client->adapter; |
747d9bed | 251 | int i, cur, conf, hyst, crit, min, max; |
1da177e4 LT |
252 | |
253 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
254 | I2C_FUNC_SMBUS_WORD_DATA)) | |
a189dd62 | 255 | return -ENODEV; |
1da177e4 LT |
256 | |
257 | /* Here comes the remaining detection. Since the LM77 has no | |
258 | register dedicated to identification, we have to rely on the | |
259 | following tricks: | |
260 | ||
261 | 1. the high 4 bits represent the sign and thus they should | |
262 | always be the same | |
263 | 2. the high 3 bits are unused in the configuration register | |
264 | 3. addresses 0x06 and 0x07 return the last read value | |
265 | 4. registers cycling over 8-address boundaries | |
266 | ||
267 | Word-sized registers are high-byte first. */ | |
1da177e4 | 268 | |
747d9bed JD |
269 | /* addresses cycling */ |
270 | cur = i2c_smbus_read_word_data(new_client, 0); | |
271 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
272 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
273 | crit = i2c_smbus_read_word_data(new_client, 3); | |
274 | min = i2c_smbus_read_word_data(new_client, 4); | |
275 | max = i2c_smbus_read_word_data(new_client, 5); | |
276 | for (i = 8; i <= 0xff; i += 8) { | |
277 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
278 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
279 | || i2c_smbus_read_word_data(new_client, i + 3) != crit | |
280 | || i2c_smbus_read_word_data(new_client, i + 4) != min | |
281 | || i2c_smbus_read_word_data(new_client, i + 5) != max) | |
a189dd62 | 282 | return -ENODEV; |
747d9bed | 283 | } |
1da177e4 | 284 | |
747d9bed JD |
285 | /* sign bits */ |
286 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
287 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
288 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
289 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
290 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
291 | return -ENODEV; | |
1da177e4 | 292 | |
747d9bed JD |
293 | /* unused bits */ |
294 | if (conf & 0xe0) | |
295 | return -ENODEV; | |
296 | ||
297 | /* 0x06 and 0x07 return the last read value */ | |
298 | cur = i2c_smbus_read_word_data(new_client, 0); | |
299 | if (i2c_smbus_read_word_data(new_client, 6) != cur | |
300 | || i2c_smbus_read_word_data(new_client, 7) != cur) | |
301 | return -ENODEV; | |
302 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
303 | if (i2c_smbus_read_word_data(new_client, 6) != hyst | |
304 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
305 | return -ENODEV; | |
306 | min = i2c_smbus_read_word_data(new_client, 4); | |
307 | if (i2c_smbus_read_word_data(new_client, 6) != min | |
308 | || i2c_smbus_read_word_data(new_client, 7) != min) | |
309 | return -ENODEV; | |
1da177e4 | 310 | |
a189dd62 | 311 | strlcpy(info->type, "lm77", I2C_NAME_SIZE); |
1da177e4 | 312 | |
a189dd62 JD |
313 | return 0; |
314 | } | |
315 | ||
316 | static int lm77_probe(struct i2c_client *new_client, | |
317 | const struct i2c_device_id *id) | |
318 | { | |
319 | struct lm77_data *data; | |
320 | int err; | |
321 | ||
322 | data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL); | |
323 | if (!data) { | |
324 | err = -ENOMEM; | |
325 | goto exit; | |
1da177e4 LT |
326 | } |
327 | ||
a189dd62 | 328 | i2c_set_clientdata(new_client, data); |
1da177e4 | 329 | data->valid = 0; |
9a61bf63 | 330 | mutex_init(&data->update_lock); |
1da177e4 | 331 | |
1da177e4 LT |
332 | /* Initialize the LM77 chip */ |
333 | lm77_init_client(new_client); | |
334 | ||
335 | /* Register sysfs hooks */ | |
0501a381 | 336 | if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group))) |
a189dd62 | 337 | goto exit_free; |
0501a381 | 338 | |
1beeffe4 TJ |
339 | data->hwmon_dev = hwmon_device_register(&new_client->dev); |
340 | if (IS_ERR(data->hwmon_dev)) { | |
341 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 342 | goto exit_remove; |
943b0830 MH |
343 | } |
344 | ||
1da177e4 LT |
345 | return 0; |
346 | ||
0501a381 MH |
347 | exit_remove: |
348 | sysfs_remove_group(&new_client->dev.kobj, &lm77_group); | |
1da177e4 LT |
349 | exit_free: |
350 | kfree(data); | |
351 | exit: | |
352 | return err; | |
353 | } | |
354 | ||
a189dd62 | 355 | static int lm77_remove(struct i2c_client *client) |
1da177e4 | 356 | { |
943b0830 | 357 | struct lm77_data *data = i2c_get_clientdata(client); |
1beeffe4 | 358 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 359 | sysfs_remove_group(&client->dev.kobj, &lm77_group); |
943b0830 | 360 | kfree(data); |
1da177e4 LT |
361 | return 0; |
362 | } | |
363 | ||
364 | /* All registers are word-sized, except for the configuration register. | |
365 | The LM77 uses the high-byte first convention. */ | |
366 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
367 | { | |
368 | if (reg == LM77_REG_CONF) | |
369 | return i2c_smbus_read_byte_data(client, reg); | |
370 | else | |
371 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
372 | } | |
373 | ||
374 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
375 | { | |
376 | if (reg == LM77_REG_CONF) | |
377 | return i2c_smbus_write_byte_data(client, reg, value); | |
378 | else | |
379 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
380 | } | |
381 | ||
382 | static void lm77_init_client(struct i2c_client *client) | |
383 | { | |
384 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
385 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
386 | if (conf & 1) | |
387 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
388 | } | |
389 | ||
390 | static struct lm77_data *lm77_update_device(struct device *dev) | |
391 | { | |
392 | struct i2c_client *client = to_i2c_client(dev); | |
393 | struct lm77_data *data = i2c_get_clientdata(client); | |
394 | ||
9a61bf63 | 395 | mutex_lock(&data->update_lock); |
1da177e4 LT |
396 | |
397 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
398 | || !data->valid) { | |
399 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
400 | data->temp_input = | |
401 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
402 | LM77_REG_TEMP)); | |
403 | data->temp_hyst = | |
404 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
405 | LM77_REG_TEMP_HYST)); | |
406 | data->temp_crit = | |
407 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
408 | LM77_REG_TEMP_CRIT)); | |
409 | data->temp_min = | |
410 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
411 | LM77_REG_TEMP_MIN)); | |
412 | data->temp_max = | |
413 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
414 | LM77_REG_TEMP_MAX)); | |
415 | data->alarms = | |
416 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
417 | data->last_updated = jiffies; | |
418 | data->valid = 1; | |
419 | } | |
420 | ||
9a61bf63 | 421 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
422 | |
423 | return data; | |
424 | } | |
425 | ||
426 | static int __init sensors_lm77_init(void) | |
427 | { | |
428 | return i2c_add_driver(&lm77_driver); | |
429 | } | |
430 | ||
431 | static void __exit sensors_lm77_exit(void) | |
432 | { | |
433 | i2c_del_driver(&lm77_driver); | |
434 | } | |
435 | ||
436 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
437 | MODULE_DESCRIPTION("LM77 driver"); | |
438 | MODULE_LICENSE("GPL"); | |
439 | ||
440 | module_init(sensors_lm77_init); | |
441 | module_exit(sensors_lm77_exit); |