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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); | |
69 | static int lm77_detect(struct i2c_client *client, int kind, | |
70 | struct i2c_board_info *info); | |
1da177e4 | 71 | static void lm77_init_client(struct i2c_client *client); |
a189dd62 | 72 | static int lm77_remove(struct i2c_client *client); |
1da177e4 LT |
73 | static u16 lm77_read_value(struct i2c_client *client, u8 reg); |
74 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value); | |
75 | ||
76 | static struct lm77_data *lm77_update_device(struct device *dev); | |
77 | ||
78 | ||
a189dd62 JD |
79 | static const struct i2c_device_id lm77_id[] = { |
80 | { "lm77", lm77 }, | |
81 | { } | |
82 | }; | |
83 | MODULE_DEVICE_TABLE(i2c, lm77_id); | |
84 | ||
1da177e4 LT |
85 | /* This is the driver that will be inserted */ |
86 | static struct i2c_driver lm77_driver = { | |
a189dd62 | 87 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 88 | .driver = { |
cdaf7934 LR |
89 | .name = "lm77", |
90 | }, | |
a189dd62 JD |
91 | .probe = lm77_probe, |
92 | .remove = lm77_remove, | |
93 | .id_table = lm77_id, | |
94 | .detect = lm77_detect, | |
95 | .address_data = &addr_data, | |
1da177e4 LT |
96 | }; |
97 | ||
98 | /* straight from the datasheet */ | |
99 | #define LM77_TEMP_MIN (-55000) | |
100 | #define LM77_TEMP_MAX 125000 | |
101 | ||
102 | /* In the temperature registers, the low 3 bits are not part of the | |
103 | temperature values; they are the status bits. */ | |
413b6451 | 104 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 LT |
105 | { |
106 | int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); | |
413b6451 | 107 | return (ntemp / 500) * 8; |
1da177e4 LT |
108 | } |
109 | ||
413b6451 | 110 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 111 | { |
413b6451 | 112 | return (reg / 8) * 500; |
1da177e4 LT |
113 | } |
114 | ||
115 | /* sysfs stuff */ | |
116 | ||
117 | /* read routines for temperature limits */ | |
118 | #define show(value) \ | |
8627f9ba | 119 | static ssize_t show_##value(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->value); \ | |
123 | } | |
124 | ||
125 | show(temp_input); | |
126 | show(temp_crit); | |
127 | show(temp_min); | |
128 | show(temp_max); | |
1da177e4 LT |
129 | |
130 | /* read routines for hysteresis values */ | |
8627f9ba | 131 | static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
132 | { |
133 | struct lm77_data *data = lm77_update_device(dev); | |
134 | return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); | |
135 | } | |
8627f9ba | 136 | static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
137 | { |
138 | struct lm77_data *data = lm77_update_device(dev); | |
139 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
140 | } | |
8627f9ba | 141 | static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
142 | { |
143 | struct lm77_data *data = lm77_update_device(dev); | |
144 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
145 | } | |
146 | ||
147 | /* write routines */ | |
148 | #define set(value, reg) \ | |
8627f9ba | 149 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \ |
1da177e4 LT |
150 | { \ |
151 | struct i2c_client *client = to_i2c_client(dev); \ | |
152 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
5bfedac0 | 153 | long val = simple_strtol(buf, NULL, 10); \ |
1da177e4 | 154 | \ |
9a61bf63 | 155 | mutex_lock(&data->update_lock); \ |
1da177e4 LT |
156 | data->value = val; \ |
157 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
9a61bf63 | 158 | mutex_unlock(&data->update_lock); \ |
1da177e4 LT |
159 | return count; \ |
160 | } | |
161 | ||
162 | set(temp_min, LM77_REG_TEMP_MIN); | |
163 | set(temp_max, LM77_REG_TEMP_MAX); | |
164 | ||
165 | /* hysteresis is stored as a relative value on the chip, so it has to be | |
166 | converted first */ | |
8627f9ba | 167 | static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
168 | { |
169 | struct i2c_client *client = to_i2c_client(dev); | |
170 | struct lm77_data *data = i2c_get_clientdata(client); | |
171 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
172 | ||
9a61bf63 | 173 | mutex_lock(&data->update_lock); |
1da177e4 LT |
174 | data->temp_hyst = data->temp_crit - val; |
175 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
176 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 177 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
178 | return count; |
179 | } | |
180 | ||
181 | /* preserve hysteresis when setting T_crit */ | |
8627f9ba | 182 | static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
1da177e4 LT |
183 | { |
184 | struct i2c_client *client = to_i2c_client(dev); | |
185 | struct lm77_data *data = i2c_get_clientdata(client); | |
186 | long val = simple_strtoul(buf, NULL, 10); | |
187 | int oldcrithyst; | |
188 | ||
9a61bf63 | 189 | mutex_lock(&data->update_lock); |
1da177e4 LT |
190 | oldcrithyst = data->temp_crit - data->temp_hyst; |
191 | data->temp_crit = val; | |
192 | data->temp_hyst = data->temp_crit - oldcrithyst; | |
193 | lm77_write_value(client, LM77_REG_TEMP_CRIT, | |
194 | LM77_TEMP_TO_REG(data->temp_crit)); | |
195 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
196 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 197 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
198 | return count; |
199 | } | |
200 | ||
1f52af0f JD |
201 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
202 | char *buf) | |
203 | { | |
204 | int bitnr = to_sensor_dev_attr(attr)->index; | |
205 | struct lm77_data *data = lm77_update_device(dev); | |
206 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
207 | } | |
208 | ||
1da177e4 LT |
209 | static DEVICE_ATTR(temp1_input, S_IRUGO, |
210 | show_temp_input, NULL); | |
211 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
212 | show_temp_crit, set_temp_crit); | |
213 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
214 | show_temp_min, set_temp_min); | |
215 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
216 | show_temp_max, set_temp_max); | |
217 | ||
218 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
219 | show_temp_crit_hyst, set_temp_crit_hyst); | |
220 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
221 | show_temp_min_hyst, NULL); | |
222 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
223 | show_temp_max_hyst, NULL); | |
224 | ||
1f52af0f JD |
225 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
226 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
227 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 | 228 | |
0501a381 MH |
229 | static struct attribute *lm77_attributes[] = { |
230 | &dev_attr_temp1_input.attr, | |
231 | &dev_attr_temp1_crit.attr, | |
232 | &dev_attr_temp1_min.attr, | |
233 | &dev_attr_temp1_max.attr, | |
234 | &dev_attr_temp1_crit_hyst.attr, | |
235 | &dev_attr_temp1_min_hyst.attr, | |
236 | &dev_attr_temp1_max_hyst.attr, | |
1f52af0f JD |
237 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
238 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
239 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
240 | NULL |
241 | }; | |
242 | ||
243 | static const struct attribute_group lm77_group = { | |
244 | .attrs = lm77_attributes, | |
245 | }; | |
246 | ||
a189dd62 JD |
247 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
248 | static int lm77_detect(struct i2c_client *new_client, int kind, | |
249 | struct i2c_board_info *info) | |
1da177e4 | 250 | { |
a189dd62 | 251 | struct i2c_adapter *adapter = new_client->adapter; |
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. */ | |
268 | if (kind < 0) { | |
269 | int i, cur, conf, hyst, crit, min, max; | |
270 | ||
271 | /* addresses cycling */ | |
272 | cur = i2c_smbus_read_word_data(new_client, 0); | |
273 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
274 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
275 | crit = i2c_smbus_read_word_data(new_client, 3); | |
276 | min = i2c_smbus_read_word_data(new_client, 4); | |
277 | max = i2c_smbus_read_word_data(new_client, 5); | |
278 | for (i = 8; i <= 0xff; i += 8) | |
279 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
280 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
281 | || i2c_smbus_read_word_data(new_client, i + 3) != crit | |
282 | || i2c_smbus_read_word_data(new_client, i + 4) != min | |
283 | || i2c_smbus_read_word_data(new_client, i + 5) != max) | |
a189dd62 | 284 | return -ENODEV; |
1da177e4 LT |
285 | |
286 | /* sign bits */ | |
287 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
288 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
289 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
290 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
291 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
a189dd62 | 292 | return -ENODEV; |
1da177e4 LT |
293 | |
294 | /* unused bits */ | |
295 | if (conf & 0xe0) | |
a189dd62 | 296 | return -ENODEV; |
1da177e4 LT |
297 | |
298 | /* 0x06 and 0x07 return the last read value */ | |
299 | cur = i2c_smbus_read_word_data(new_client, 0); | |
300 | if (i2c_smbus_read_word_data(new_client, 6) != cur | |
301 | || i2c_smbus_read_word_data(new_client, 7) != cur) | |
a189dd62 | 302 | return -ENODEV; |
1da177e4 LT |
303 | hyst = i2c_smbus_read_word_data(new_client, 2); |
304 | if (i2c_smbus_read_word_data(new_client, 6) != hyst | |
305 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
a189dd62 | 306 | return -ENODEV; |
1da177e4 LT |
307 | min = i2c_smbus_read_word_data(new_client, 4); |
308 | if (i2c_smbus_read_word_data(new_client, 6) != min | |
309 | || i2c_smbus_read_word_data(new_client, 7) != min) | |
a189dd62 | 310 | return -ENODEV; |
1da177e4 LT |
311 | |
312 | } | |
313 | ||
a189dd62 | 314 | strlcpy(info->type, "lm77", I2C_NAME_SIZE); |
1da177e4 | 315 | |
a189dd62 JD |
316 | return 0; |
317 | } | |
318 | ||
319 | static int lm77_probe(struct i2c_client *new_client, | |
320 | const struct i2c_device_id *id) | |
321 | { | |
322 | struct lm77_data *data; | |
323 | int err; | |
324 | ||
325 | data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL); | |
326 | if (!data) { | |
327 | err = -ENOMEM; | |
328 | goto exit; | |
1da177e4 LT |
329 | } |
330 | ||
a189dd62 | 331 | i2c_set_clientdata(new_client, data); |
1da177e4 | 332 | data->valid = 0; |
9a61bf63 | 333 | mutex_init(&data->update_lock); |
1da177e4 | 334 | |
1da177e4 LT |
335 | /* Initialize the LM77 chip */ |
336 | lm77_init_client(new_client); | |
337 | ||
338 | /* Register sysfs hooks */ | |
0501a381 | 339 | if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group))) |
a189dd62 | 340 | goto exit_free; |
0501a381 | 341 | |
1beeffe4 TJ |
342 | data->hwmon_dev = hwmon_device_register(&new_client->dev); |
343 | if (IS_ERR(data->hwmon_dev)) { | |
344 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 345 | goto exit_remove; |
943b0830 MH |
346 | } |
347 | ||
1da177e4 LT |
348 | return 0; |
349 | ||
0501a381 MH |
350 | exit_remove: |
351 | sysfs_remove_group(&new_client->dev.kobj, &lm77_group); | |
1da177e4 LT |
352 | exit_free: |
353 | kfree(data); | |
354 | exit: | |
355 | return err; | |
356 | } | |
357 | ||
a189dd62 | 358 | static int lm77_remove(struct i2c_client *client) |
1da177e4 | 359 | { |
943b0830 | 360 | struct lm77_data *data = i2c_get_clientdata(client); |
1beeffe4 | 361 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 362 | sysfs_remove_group(&client->dev.kobj, &lm77_group); |
943b0830 | 363 | kfree(data); |
1da177e4 LT |
364 | return 0; |
365 | } | |
366 | ||
367 | /* All registers are word-sized, except for the configuration register. | |
368 | The LM77 uses the high-byte first convention. */ | |
369 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
370 | { | |
371 | if (reg == LM77_REG_CONF) | |
372 | return i2c_smbus_read_byte_data(client, reg); | |
373 | else | |
374 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
375 | } | |
376 | ||
377 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
378 | { | |
379 | if (reg == LM77_REG_CONF) | |
380 | return i2c_smbus_write_byte_data(client, reg, value); | |
381 | else | |
382 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
383 | } | |
384 | ||
385 | static void lm77_init_client(struct i2c_client *client) | |
386 | { | |
387 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
388 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
389 | if (conf & 1) | |
390 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
391 | } | |
392 | ||
393 | static struct lm77_data *lm77_update_device(struct device *dev) | |
394 | { | |
395 | struct i2c_client *client = to_i2c_client(dev); | |
396 | struct lm77_data *data = i2c_get_clientdata(client); | |
397 | ||
9a61bf63 | 398 | mutex_lock(&data->update_lock); |
1da177e4 LT |
399 | |
400 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
401 | || !data->valid) { | |
402 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
403 | data->temp_input = | |
404 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
405 | LM77_REG_TEMP)); | |
406 | data->temp_hyst = | |
407 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
408 | LM77_REG_TEMP_HYST)); | |
409 | data->temp_crit = | |
410 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
411 | LM77_REG_TEMP_CRIT)); | |
412 | data->temp_min = | |
413 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
414 | LM77_REG_TEMP_MIN)); | |
415 | data->temp_max = | |
416 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
417 | LM77_REG_TEMP_MAX)); | |
418 | data->alarms = | |
419 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
420 | data->last_updated = jiffies; | |
421 | data->valid = 1; | |
422 | } | |
423 | ||
9a61bf63 | 424 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
425 | |
426 | return data; | |
427 | } | |
428 | ||
429 | static int __init sensors_lm77_init(void) | |
430 | { | |
431 | return i2c_add_driver(&lm77_driver); | |
432 | } | |
433 | ||
434 | static void __exit sensors_lm77_exit(void) | |
435 | { | |
436 | i2c_del_driver(&lm77_driver); | |
437 | } | |
438 | ||
439 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
440 | MODULE_DESCRIPTION("LM77 driver"); | |
441 | MODULE_LICENSE("GPL"); | |
442 | ||
443 | module_init(sensors_lm77_init); | |
444 | module_exit(sensors_lm77_exit); |