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Commit | Line | Data |
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1da177e4 | 1 | /* |
02fe2fd9 GR |
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. | |
02fe2fd9 | 22 | */ |
1da177e4 | 23 | |
1da177e4 LT |
24 | #include <linux/module.h> |
25 | #include <linux/init.h> | |
26 | #include <linux/slab.h> | |
27 | #include <linux/jiffies.h> | |
28 | #include <linux/i2c.h> | |
943b0830 | 29 | #include <linux/hwmon.h> |
1f52af0f | 30 | #include <linux/hwmon-sysfs.h> |
943b0830 | 31 | #include <linux/err.h> |
9a61bf63 | 32 | #include <linux/mutex.h> |
1da177e4 LT |
33 | |
34 | /* Addresses to scan */ | |
25e9c86d MH |
35 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
36 | I2C_CLIENT_END }; | |
1da177e4 | 37 | |
1da177e4 LT |
38 | /* The LM77 registers */ |
39 | #define LM77_REG_TEMP 0x00 | |
40 | #define LM77_REG_CONF 0x01 | |
41 | #define LM77_REG_TEMP_HYST 0x02 | |
42 | #define LM77_REG_TEMP_CRIT 0x03 | |
43 | #define LM77_REG_TEMP_MIN 0x04 | |
44 | #define LM77_REG_TEMP_MAX 0x05 | |
45 | ||
46 | /* Each client has this additional data */ | |
47 | struct lm77_data { | |
02fe2fd9 | 48 | struct device *hwmon_dev; |
9a61bf63 | 49 | struct mutex update_lock; |
1da177e4 LT |
50 | char valid; |
51 | unsigned long last_updated; /* In jiffies */ | |
52 | int temp_input; /* Temperatures */ | |
53 | int temp_crit; | |
54 | int temp_min; | |
55 | int temp_max; | |
56 | int temp_hyst; | |
57 | u8 alarms; | |
58 | }; | |
59 | ||
1da177e4 LT |
60 | /* straight from the datasheet */ |
61 | #define LM77_TEMP_MIN (-55000) | |
62 | #define LM77_TEMP_MAX 125000 | |
63 | ||
02fe2fd9 GR |
64 | /* |
65 | * In the temperature registers, the low 3 bits are not part of the | |
66 | * temperature values; they are the status bits. | |
67 | */ | |
413b6451 | 68 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 | 69 | { |
2a844c14 | 70 | int ntemp = clamp_val(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); |
413b6451 | 71 | return (ntemp / 500) * 8; |
1da177e4 LT |
72 | } |
73 | ||
413b6451 | 74 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 75 | { |
413b6451 | 76 | return (reg / 8) * 500; |
1da177e4 LT |
77 | } |
78 | ||
9f9edcd4 GR |
79 | /* |
80 | * All registers are word-sized, except for the configuration register. | |
81 | * The LM77 uses the high-byte first convention. | |
82 | */ | |
83 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
84 | { | |
85 | if (reg == LM77_REG_CONF) | |
86 | return i2c_smbus_read_byte_data(client, reg); | |
87 | else | |
88 | return i2c_smbus_read_word_swapped(client, reg); | |
89 | } | |
90 | ||
91 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
92 | { | |
93 | if (reg == LM77_REG_CONF) | |
94 | return i2c_smbus_write_byte_data(client, reg, value); | |
95 | else | |
96 | return i2c_smbus_write_word_swapped(client, reg, value); | |
97 | } | |
98 | ||
99 | static struct lm77_data *lm77_update_device(struct device *dev) | |
100 | { | |
101 | struct i2c_client *client = to_i2c_client(dev); | |
102 | struct lm77_data *data = i2c_get_clientdata(client); | |
103 | ||
104 | mutex_lock(&data->update_lock); | |
105 | ||
106 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
107 | || !data->valid) { | |
108 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
109 | data->temp_input = | |
110 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
111 | LM77_REG_TEMP)); | |
112 | data->temp_hyst = | |
113 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
114 | LM77_REG_TEMP_HYST)); | |
115 | data->temp_crit = | |
116 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
117 | LM77_REG_TEMP_CRIT)); | |
118 | data->temp_min = | |
119 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
120 | LM77_REG_TEMP_MIN)); | |
121 | data->temp_max = | |
122 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
123 | LM77_REG_TEMP_MAX)); | |
124 | data->alarms = | |
125 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
126 | data->last_updated = jiffies; | |
127 | data->valid = 1; | |
128 | } | |
129 | ||
130 | mutex_unlock(&data->update_lock); | |
131 | ||
132 | return data; | |
133 | } | |
134 | ||
1da177e4 LT |
135 | /* sysfs stuff */ |
136 | ||
137 | /* read routines for temperature limits */ | |
138 | #define show(value) \ | |
02fe2fd9 GR |
139 | static ssize_t show_##value(struct device *dev, \ |
140 | struct device_attribute *attr, \ | |
141 | char *buf) \ | |
1da177e4 LT |
142 | { \ |
143 | struct lm77_data *data = lm77_update_device(dev); \ | |
144 | return sprintf(buf, "%d\n", data->value); \ | |
145 | } | |
146 | ||
147 | show(temp_input); | |
148 | show(temp_crit); | |
149 | show(temp_min); | |
150 | show(temp_max); | |
1da177e4 LT |
151 | |
152 | /* read routines for hysteresis values */ | |
02fe2fd9 GR |
153 | static ssize_t show_temp_crit_hyst(struct device *dev, |
154 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
155 | { |
156 | struct lm77_data *data = lm77_update_device(dev); | |
157 | return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); | |
158 | } | |
02fe2fd9 GR |
159 | static ssize_t show_temp_min_hyst(struct device *dev, |
160 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
161 | { |
162 | struct lm77_data *data = lm77_update_device(dev); | |
163 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
164 | } | |
02fe2fd9 GR |
165 | static ssize_t show_temp_max_hyst(struct device *dev, |
166 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
167 | { |
168 | struct lm77_data *data = lm77_update_device(dev); | |
169 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
170 | } | |
171 | ||
172 | /* write routines */ | |
173 | #define set(value, reg) \ | |
02fe2fd9 GR |
174 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \ |
175 | const char *buf, size_t count) \ | |
176 | { \ | |
177 | struct i2c_client *client = to_i2c_client(dev); \ | |
178 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
179 | long val; \ | |
180 | int err = kstrtol(buf, 10, &val); \ | |
181 | if (err) \ | |
182 | return err; \ | |
183 | \ | |
184 | mutex_lock(&data->update_lock); \ | |
185 | data->value = val; \ | |
186 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
187 | mutex_unlock(&data->update_lock); \ | |
188 | return count; \ | |
1da177e4 LT |
189 | } |
190 | ||
191 | set(temp_min, LM77_REG_TEMP_MIN); | |
192 | set(temp_max, LM77_REG_TEMP_MAX); | |
193 | ||
02fe2fd9 GR |
194 | /* |
195 | * hysteresis is stored as a relative value on the chip, so it has to be | |
196 | * converted first | |
197 | */ | |
198 | static ssize_t set_temp_crit_hyst(struct device *dev, | |
199 | struct device_attribute *attr, | |
200 | const char *buf, size_t count) | |
1da177e4 LT |
201 | { |
202 | struct i2c_client *client = to_i2c_client(dev); | |
203 | struct lm77_data *data = i2c_get_clientdata(client); | |
02fe2fd9 GR |
204 | unsigned long val; |
205 | int err; | |
206 | ||
207 | err = kstrtoul(buf, 10, &val); | |
208 | if (err) | |
209 | return err; | |
1da177e4 | 210 | |
9a61bf63 | 211 | mutex_lock(&data->update_lock); |
1da177e4 LT |
212 | data->temp_hyst = data->temp_crit - val; |
213 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
214 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 215 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
216 | return count; |
217 | } | |
218 | ||
02fe2fd9 GR |
219 | static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, |
220 | const char *buf, size_t count) | |
1da177e4 LT |
221 | { |
222 | struct i2c_client *client = to_i2c_client(dev); | |
223 | struct lm77_data *data = i2c_get_clientdata(client); | |
02fe2fd9 GR |
224 | unsigned long val; |
225 | int err; | |
226 | ||
227 | err = kstrtoul(buf, 10, &val); | |
228 | if (err) | |
229 | return err; | |
230 | ||
9a61bf63 | 231 | mutex_lock(&data->update_lock); |
1da177e4 | 232 | data->temp_crit = val; |
1da177e4 LT |
233 | lm77_write_value(client, LM77_REG_TEMP_CRIT, |
234 | LM77_TEMP_TO_REG(data->temp_crit)); | |
9a61bf63 | 235 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
236 | return count; |
237 | } | |
238 | ||
1f52af0f JD |
239 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
240 | char *buf) | |
241 | { | |
242 | int bitnr = to_sensor_dev_attr(attr)->index; | |
243 | struct lm77_data *data = lm77_update_device(dev); | |
244 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
245 | } | |
246 | ||
1da177e4 LT |
247 | static DEVICE_ATTR(temp1_input, S_IRUGO, |
248 | show_temp_input, NULL); | |
249 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
250 | show_temp_crit, set_temp_crit); | |
251 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
252 | show_temp_min, set_temp_min); | |
253 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
254 | show_temp_max, set_temp_max); | |
255 | ||
256 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
257 | show_temp_crit_hyst, set_temp_crit_hyst); | |
258 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
259 | show_temp_min_hyst, NULL); | |
260 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
261 | show_temp_max_hyst, NULL); | |
262 | ||
1f52af0f JD |
263 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
264 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
265 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 | 266 | |
0501a381 MH |
267 | static struct attribute *lm77_attributes[] = { |
268 | &dev_attr_temp1_input.attr, | |
269 | &dev_attr_temp1_crit.attr, | |
270 | &dev_attr_temp1_min.attr, | |
271 | &dev_attr_temp1_max.attr, | |
272 | &dev_attr_temp1_crit_hyst.attr, | |
273 | &dev_attr_temp1_min_hyst.attr, | |
274 | &dev_attr_temp1_max_hyst.attr, | |
1f52af0f JD |
275 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
276 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
277 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
278 | NULL |
279 | }; | |
280 | ||
281 | static const struct attribute_group lm77_group = { | |
282 | .attrs = lm77_attributes, | |
283 | }; | |
284 | ||
a189dd62 | 285 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
efd2d117 | 286 | static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info) |
1da177e4 | 287 | { |
efd2d117 | 288 | struct i2c_adapter *adapter = client->adapter; |
747d9bed | 289 | int i, cur, conf, hyst, crit, min, max; |
1da177e4 LT |
290 | |
291 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
292 | I2C_FUNC_SMBUS_WORD_DATA)) | |
a189dd62 | 293 | return -ENODEV; |
1da177e4 | 294 | |
02fe2fd9 GR |
295 | /* |
296 | * Here comes the remaining detection. Since the LM77 has no | |
297 | * register dedicated to identification, we have to rely on the | |
298 | * following tricks: | |
299 | * | |
300 | * 1. the high 4 bits represent the sign and thus they should | |
301 | * always be the same | |
302 | * 2. the high 3 bits are unused in the configuration register | |
303 | * 3. addresses 0x06 and 0x07 return the last read value | |
304 | * 4. registers cycling over 8-address boundaries | |
305 | * | |
306 | * Word-sized registers are high-byte first. | |
307 | */ | |
1da177e4 | 308 | |
747d9bed | 309 | /* addresses cycling */ |
efd2d117 GR |
310 | cur = i2c_smbus_read_word_data(client, 0); |
311 | conf = i2c_smbus_read_byte_data(client, 1); | |
312 | hyst = i2c_smbus_read_word_data(client, 2); | |
313 | crit = i2c_smbus_read_word_data(client, 3); | |
314 | min = i2c_smbus_read_word_data(client, 4); | |
315 | max = i2c_smbus_read_word_data(client, 5); | |
747d9bed | 316 | for (i = 8; i <= 0xff; i += 8) { |
efd2d117 GR |
317 | if (i2c_smbus_read_byte_data(client, i + 1) != conf |
318 | || i2c_smbus_read_word_data(client, i + 2) != hyst | |
319 | || i2c_smbus_read_word_data(client, i + 3) != crit | |
320 | || i2c_smbus_read_word_data(client, i + 4) != min | |
321 | || i2c_smbus_read_word_data(client, i + 5) != max) | |
a189dd62 | 322 | return -ENODEV; |
747d9bed | 323 | } |
1da177e4 | 324 | |
747d9bed JD |
325 | /* sign bits */ |
326 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
327 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
328 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
329 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
330 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
331 | return -ENODEV; | |
1da177e4 | 332 | |
747d9bed JD |
333 | /* unused bits */ |
334 | if (conf & 0xe0) | |
335 | return -ENODEV; | |
336 | ||
337 | /* 0x06 and 0x07 return the last read value */ | |
efd2d117 GR |
338 | cur = i2c_smbus_read_word_data(client, 0); |
339 | if (i2c_smbus_read_word_data(client, 6) != cur | |
340 | || i2c_smbus_read_word_data(client, 7) != cur) | |
747d9bed | 341 | return -ENODEV; |
efd2d117 GR |
342 | hyst = i2c_smbus_read_word_data(client, 2); |
343 | if (i2c_smbus_read_word_data(client, 6) != hyst | |
344 | || i2c_smbus_read_word_data(client, 7) != hyst) | |
747d9bed | 345 | return -ENODEV; |
efd2d117 GR |
346 | min = i2c_smbus_read_word_data(client, 4); |
347 | if (i2c_smbus_read_word_data(client, 6) != min | |
348 | || i2c_smbus_read_word_data(client, 7) != min) | |
747d9bed | 349 | return -ENODEV; |
1da177e4 | 350 | |
a189dd62 | 351 | strlcpy(info->type, "lm77", I2C_NAME_SIZE); |
1da177e4 | 352 | |
a189dd62 JD |
353 | return 0; |
354 | } | |
355 | ||
9f9edcd4 GR |
356 | static void lm77_init_client(struct i2c_client *client) |
357 | { | |
358 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
359 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
360 | if (conf & 1) | |
361 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
362 | } | |
363 | ||
efd2d117 | 364 | static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id) |
a189dd62 | 365 | { |
efd2d117 | 366 | struct device *dev = &client->dev; |
a189dd62 JD |
367 | struct lm77_data *data; |
368 | int err; | |
369 | ||
52714c04 GR |
370 | data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL); |
371 | if (!data) | |
372 | return -ENOMEM; | |
1da177e4 | 373 | |
efd2d117 | 374 | i2c_set_clientdata(client, data); |
9a61bf63 | 375 | mutex_init(&data->update_lock); |
1da177e4 | 376 | |
1da177e4 | 377 | /* Initialize the LM77 chip */ |
efd2d117 | 378 | lm77_init_client(client); |
1da177e4 LT |
379 | |
380 | /* Register sysfs hooks */ | |
efd2d117 | 381 | err = sysfs_create_group(&dev->kobj, &lm77_group); |
02fe2fd9 | 382 | if (err) |
52714c04 | 383 | return err; |
0501a381 | 384 | |
efd2d117 | 385 | data->hwmon_dev = hwmon_device_register(dev); |
1beeffe4 TJ |
386 | if (IS_ERR(data->hwmon_dev)) { |
387 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 388 | goto exit_remove; |
943b0830 MH |
389 | } |
390 | ||
1da177e4 LT |
391 | return 0; |
392 | ||
0501a381 | 393 | exit_remove: |
efd2d117 | 394 | sysfs_remove_group(&dev->kobj, &lm77_group); |
1da177e4 LT |
395 | return err; |
396 | } | |
397 | ||
a189dd62 | 398 | static int lm77_remove(struct i2c_client *client) |
1da177e4 | 399 | { |
943b0830 | 400 | struct lm77_data *data = i2c_get_clientdata(client); |
1beeffe4 | 401 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 402 | sysfs_remove_group(&client->dev.kobj, &lm77_group); |
1da177e4 LT |
403 | return 0; |
404 | } | |
405 | ||
9f9edcd4 GR |
406 | static const struct i2c_device_id lm77_id[] = { |
407 | { "lm77", 0 }, | |
408 | { } | |
409 | }; | |
410 | MODULE_DEVICE_TABLE(i2c, lm77_id); | |
1da177e4 | 411 | |
9f9edcd4 GR |
412 | /* This is the driver that will be inserted */ |
413 | static struct i2c_driver lm77_driver = { | |
414 | .class = I2C_CLASS_HWMON, | |
415 | .driver = { | |
416 | .name = "lm77", | |
417 | }, | |
418 | .probe = lm77_probe, | |
419 | .remove = lm77_remove, | |
420 | .id_table = lm77_id, | |
421 | .detect = lm77_detect, | |
422 | .address_list = normal_i2c, | |
423 | }; | |
1da177e4 | 424 | |
f0967eea | 425 | module_i2c_driver(lm77_driver); |
1da177e4 LT |
426 | |
427 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
428 | MODULE_DESCRIPTION("LM77 driver"); | |
429 | MODULE_LICENSE("GPL"); |