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1da177e4 | 1 | /* |
caaa0f36 S |
2 | * lm75.c - Part of lm_sensors, Linux kernel modules for hardware |
3 | * monitoring | |
4 | * Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl> | |
5 | * | |
6 | * This program is free software; you can redistribute it and/or modify | |
7 | * it under the terms of the GNU General Public License as published by | |
8 | * the Free Software Foundation; either version 2 of the License, or | |
9 | * (at your option) any later version. | |
10 | * | |
11 | * This program is distributed in the hope that it will be useful, | |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | * GNU General Public License for more details. | |
15 | * | |
16 | * You should have received a copy of the GNU General Public License | |
17 | * along with this program; if not, write to the Free Software | |
18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
1da177e4 | 20 | |
1da177e4 LT |
21 | #include <linux/module.h> |
22 | #include <linux/init.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/jiffies.h> | |
25 | #include <linux/i2c.h> | |
943b0830 | 26 | #include <linux/hwmon.h> |
9ca8e40c | 27 | #include <linux/hwmon-sysfs.h> |
943b0830 | 28 | #include <linux/err.h> |
9a61bf63 | 29 | #include <linux/mutex.h> |
22e73183 EV |
30 | #include <linux/of.h> |
31 | #include <linux/thermal.h> | |
1da177e4 LT |
32 | #include "lm75.h" |
33 | ||
34 | ||
01a52397 DB |
35 | /* |
36 | * This driver handles the LM75 and compatible digital temperature sensors. | |
01a52397 DB |
37 | */ |
38 | ||
9ebd3d82 | 39 | enum lm75_type { /* keep sorted in alphabetical order */ |
e96f9d89 | 40 | adt75, |
1f86df49 | 41 | ds1775, |
9ebd3d82 | 42 | ds75, |
3fbc81e3 | 43 | ds7505, |
c98d6c65 | 44 | g751, |
1f86df49 | 45 | lm75, |
9ebd3d82 | 46 | lm75a, |
799fc602 | 47 | lm75b, |
9ebd3d82 DB |
48 | max6625, |
49 | max6626, | |
50 | mcp980x, | |
51 | stds75, | |
52 | tcn75, | |
53 | tmp100, | |
54 | tmp101, | |
6d034059 | 55 | tmp105, |
c83959f8 | 56 | tmp112, |
9ebd3d82 DB |
57 | tmp175, |
58 | tmp275, | |
59 | tmp75, | |
60 | }; | |
61 | ||
8ff69eeb | 62 | /* Addresses scanned */ |
25e9c86d | 63 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, |
1da177e4 | 64 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; |
1da177e4 | 65 | |
1da177e4 LT |
66 | |
67 | /* The LM75 registers */ | |
1da177e4 | 68 | #define LM75_REG_CONF 0x01 |
9ca8e40c JD |
69 | static const u8 LM75_REG_TEMP[3] = { |
70 | 0x00, /* input */ | |
71 | 0x03, /* max */ | |
72 | 0x02, /* hyst */ | |
73 | }; | |
1da177e4 LT |
74 | |
75 | /* Each client has this additional data */ | |
76 | struct lm75_data { | |
d663ec49 | 77 | struct i2c_client *client; |
01a52397 | 78 | struct device *hwmon_dev; |
22e73183 | 79 | struct thermal_zone_device *tz; |
9a61bf63 | 80 | struct mutex update_lock; |
9ebd3d82 | 81 | u8 orig_conf; |
87d0621a JD |
82 | u8 resolution; /* In bits, between 9 and 12 */ |
83 | u8 resolution_limits; | |
01a52397 | 84 | char valid; /* !=0 if registers are valid */ |
1da177e4 | 85 | unsigned long last_updated; /* In jiffies */ |
87d0621a JD |
86 | unsigned long sample_time; /* In jiffies */ |
87 | s16 temp[3]; /* Register values, | |
9ca8e40c JD |
88 | 0 = input |
89 | 1 = max | |
90 | 2 = hyst */ | |
1da177e4 LT |
91 | }; |
92 | ||
1da177e4 LT |
93 | static int lm75_read_value(struct i2c_client *client, u8 reg); |
94 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); | |
95 | static struct lm75_data *lm75_update_device(struct device *dev); | |
96 | ||
97 | ||
01a52397 DB |
98 | /*-----------------------------------------------------------------------*/ |
99 | ||
22e73183 EV |
100 | static inline long lm75_reg_to_mc(s16 temp, u8 resolution) |
101 | { | |
102 | return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8); | |
103 | } | |
104 | ||
01a52397 | 105 | /* sysfs attributes for hwmon */ |
1da177e4 | 106 | |
22e73183 EV |
107 | static int lm75_read_temp(void *dev, long *temp) |
108 | { | |
109 | struct lm75_data *data = lm75_update_device(dev); | |
110 | ||
111 | if (IS_ERR(data)) | |
112 | return PTR_ERR(data); | |
113 | ||
114 | *temp = lm75_reg_to_mc(data->temp[0], data->resolution); | |
115 | ||
116 | return 0; | |
117 | } | |
118 | ||
9ca8e40c JD |
119 | static ssize_t show_temp(struct device *dev, struct device_attribute *da, |
120 | char *buf) | |
121 | { | |
122 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
123 | struct lm75_data *data = lm75_update_device(dev); | |
1f962f36 FM |
124 | |
125 | if (IS_ERR(data)) | |
126 | return PTR_ERR(data); | |
127 | ||
22e73183 EV |
128 | return sprintf(buf, "%ld\n", lm75_reg_to_mc(data->temp[attr->index], |
129 | data->resolution)); | |
1da177e4 | 130 | } |
9ca8e40c JD |
131 | |
132 | static ssize_t set_temp(struct device *dev, struct device_attribute *da, | |
133 | const char *buf, size_t count) | |
134 | { | |
135 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
d663ec49 GR |
136 | struct lm75_data *data = dev_get_drvdata(dev); |
137 | struct i2c_client *client = data->client; | |
9ca8e40c | 138 | int nr = attr->index; |
e3cd9528 S |
139 | long temp; |
140 | int error; | |
87d0621a | 141 | u8 resolution; |
e3cd9528 | 142 | |
24edc0a7 | 143 | error = kstrtol(buf, 10, &temp); |
e3cd9528 S |
144 | if (error) |
145 | return error; | |
9ca8e40c | 146 | |
87d0621a JD |
147 | /* |
148 | * Resolution of limit registers is assumed to be the same as the | |
149 | * temperature input register resolution unless given explicitly. | |
150 | */ | |
151 | if (attr->index && data->resolution_limits) | |
152 | resolution = data->resolution_limits; | |
153 | else | |
154 | resolution = data->resolution; | |
155 | ||
9ca8e40c | 156 | mutex_lock(&data->update_lock); |
87d0621a JD |
157 | temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX); |
158 | data->temp[nr] = DIV_ROUND_CLOSEST(temp << (resolution - 8), | |
159 | 1000) << (16 - resolution); | |
9ca8e40c JD |
160 | lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]); |
161 | mutex_unlock(&data->update_lock); | |
162 | return count; | |
1da177e4 | 163 | } |
1da177e4 | 164 | |
9ca8e40c JD |
165 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, |
166 | show_temp, set_temp, 1); | |
167 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, | |
168 | show_temp, set_temp, 2); | |
169 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); | |
1da177e4 | 170 | |
d663ec49 | 171 | static struct attribute *lm75_attrs[] = { |
9ca8e40c JD |
172 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
173 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
174 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
c1685f61 MH |
175 | |
176 | NULL | |
177 | }; | |
d663ec49 | 178 | ATTRIBUTE_GROUPS(lm75); |
c1685f61 | 179 | |
01a52397 DB |
180 | /*-----------------------------------------------------------------------*/ |
181 | ||
8ff69eeb | 182 | /* device probe and removal */ |
9ebd3d82 DB |
183 | |
184 | static int | |
185 | lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) | |
186 | { | |
d663ec49 | 187 | struct device *dev = &client->dev; |
9ebd3d82 DB |
188 | struct lm75_data *data; |
189 | int status; | |
190 | u8 set_mask, clr_mask; | |
191 | int new; | |
0cd2c72d | 192 | enum lm75_type kind = id->driver_data; |
9ebd3d82 DB |
193 | |
194 | if (!i2c_check_functionality(client->adapter, | |
195 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) | |
196 | return -EIO; | |
197 | ||
d663ec49 | 198 | data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL); |
9ebd3d82 DB |
199 | if (!data) |
200 | return -ENOMEM; | |
201 | ||
d663ec49 | 202 | data->client = client; |
9ebd3d82 | 203 | i2c_set_clientdata(client, data); |
9ebd3d82 DB |
204 | mutex_init(&data->update_lock); |
205 | ||
206 | /* Set to LM75 resolution (9 bits, 1/2 degree C) and range. | |
207 | * Then tweak to be more precise when appropriate. | |
208 | */ | |
209 | set_mask = 0; | |
8a5c5cc6 JD |
210 | clr_mask = LM75_SHUTDOWN; /* continuous conversions */ |
211 | ||
0cd2c72d | 212 | switch (kind) { |
8a5c5cc6 JD |
213 | case adt75: |
214 | clr_mask |= 1 << 5; /* not one-shot mode */ | |
0cd2c72d JD |
215 | data->resolution = 12; |
216 | data->sample_time = HZ / 8; | |
8a5c5cc6 JD |
217 | break; |
218 | case ds1775: | |
219 | case ds75: | |
220 | case stds75: | |
0cd2c72d JD |
221 | clr_mask |= 3 << 5; |
222 | set_mask |= 2 << 5; /* 11-bit mode */ | |
223 | data->resolution = 11; | |
224 | data->sample_time = HZ; | |
225 | break; | |
3fbc81e3 JD |
226 | case ds7505: |
227 | set_mask |= 3 << 5; /* 12-bit mode */ | |
228 | data->resolution = 12; | |
229 | data->sample_time = HZ / 4; | |
230 | break; | |
c98d6c65 | 231 | case g751: |
0cd2c72d JD |
232 | case lm75: |
233 | case lm75a: | |
234 | data->resolution = 9; | |
235 | data->sample_time = HZ / 2; | |
236 | break; | |
799fc602 MT |
237 | case lm75b: |
238 | data->resolution = 11; | |
239 | data->sample_time = HZ / 4; | |
240 | break; | |
0cd2c72d JD |
241 | case max6625: |
242 | data->resolution = 9; | |
243 | data->sample_time = HZ / 4; | |
244 | break; | |
245 | case max6626: | |
246 | data->resolution = 12; | |
247 | data->resolution_limits = 9; | |
248 | data->sample_time = HZ / 4; | |
249 | break; | |
250 | case tcn75: | |
251 | data->resolution = 9; | |
252 | data->sample_time = HZ / 8; | |
8a5c5cc6 JD |
253 | break; |
254 | case mcp980x: | |
0cd2c72d JD |
255 | data->resolution_limits = 9; |
256 | /* fall through */ | |
8a5c5cc6 JD |
257 | case tmp100: |
258 | case tmp101: | |
0cd2c72d JD |
259 | set_mask |= 3 << 5; /* 12-bit mode */ |
260 | data->resolution = 12; | |
261 | data->sample_time = HZ; | |
262 | clr_mask |= 1 << 7; /* not one-shot mode */ | |
263 | break; | |
c83959f8 FK |
264 | case tmp112: |
265 | set_mask |= 3 << 5; /* 12-bit mode */ | |
266 | clr_mask |= 1 << 7; /* not one-shot mode */ | |
267 | data->resolution = 12; | |
268 | data->sample_time = HZ / 4; | |
269 | break; | |
8a5c5cc6 JD |
270 | case tmp105: |
271 | case tmp175: | |
272 | case tmp275: | |
273 | case tmp75: | |
0cd2c72d | 274 | set_mask |= 3 << 5; /* 12-bit mode */ |
8a5c5cc6 | 275 | clr_mask |= 1 << 7; /* not one-shot mode */ |
0cd2c72d JD |
276 | data->resolution = 12; |
277 | data->sample_time = HZ / 2; | |
8a5c5cc6 JD |
278 | break; |
279 | } | |
9ebd3d82 DB |
280 | |
281 | /* configure as specified */ | |
282 | status = lm75_read_value(client, LM75_REG_CONF); | |
283 | if (status < 0) { | |
d663ec49 | 284 | dev_dbg(dev, "Can't read config? %d\n", status); |
13ac7a01 | 285 | return status; |
9ebd3d82 DB |
286 | } |
287 | data->orig_conf = status; | |
288 | new = status & ~clr_mask; | |
289 | new |= set_mask; | |
290 | if (status != new) | |
291 | lm75_write_value(client, LM75_REG_CONF, new); | |
d663ec49 | 292 | dev_dbg(dev, "Config %02x\n", new); |
9ebd3d82 | 293 | |
d663ec49 GR |
294 | data->hwmon_dev = hwmon_device_register_with_groups(dev, client->name, |
295 | data, lm75_groups); | |
296 | if (IS_ERR(data->hwmon_dev)) | |
297 | return PTR_ERR(data->hwmon_dev); | |
9ebd3d82 | 298 | |
d663ec49 | 299 | data->tz = thermal_zone_of_sensor_register(data->hwmon_dev, |
22e73183 | 300 | 0, |
d663ec49 | 301 | data->hwmon_dev, |
22e73183 EV |
302 | lm75_read_temp, NULL); |
303 | if (IS_ERR(data->tz)) | |
304 | data->tz = NULL; | |
305 | ||
d663ec49 | 306 | dev_info(dev, "%s: sensor '%s'\n", |
739cf3a2 | 307 | dev_name(data->hwmon_dev), client->name); |
9ebd3d82 DB |
308 | |
309 | return 0; | |
9ebd3d82 DB |
310 | } |
311 | ||
312 | static int lm75_remove(struct i2c_client *client) | |
313 | { | |
314 | struct lm75_data *data = i2c_get_clientdata(client); | |
315 | ||
d663ec49 | 316 | thermal_zone_of_sensor_unregister(data->hwmon_dev, data->tz); |
9ebd3d82 | 317 | hwmon_device_unregister(data->hwmon_dev); |
9ebd3d82 | 318 | lm75_write_value(client, LM75_REG_CONF, data->orig_conf); |
9ebd3d82 DB |
319 | return 0; |
320 | } | |
321 | ||
322 | static const struct i2c_device_id lm75_ids[] = { | |
e96f9d89 | 323 | { "adt75", adt75, }, |
9ebd3d82 DB |
324 | { "ds1775", ds1775, }, |
325 | { "ds75", ds75, }, | |
3fbc81e3 | 326 | { "ds7505", ds7505, }, |
c98d6c65 | 327 | { "g751", g751, }, |
9ebd3d82 DB |
328 | { "lm75", lm75, }, |
329 | { "lm75a", lm75a, }, | |
799fc602 | 330 | { "lm75b", lm75b, }, |
9ebd3d82 DB |
331 | { "max6625", max6625, }, |
332 | { "max6626", max6626, }, | |
333 | { "mcp980x", mcp980x, }, | |
334 | { "stds75", stds75, }, | |
335 | { "tcn75", tcn75, }, | |
336 | { "tmp100", tmp100, }, | |
337 | { "tmp101", tmp101, }, | |
6d034059 | 338 | { "tmp105", tmp105, }, |
c83959f8 | 339 | { "tmp112", tmp112, }, |
9ebd3d82 DB |
340 | { "tmp175", tmp175, }, |
341 | { "tmp275", tmp275, }, | |
342 | { "tmp75", tmp75, }, | |
343 | { /* LIST END */ } | |
344 | }; | |
345 | MODULE_DEVICE_TABLE(i2c, lm75_ids); | |
346 | ||
05e82fe4 LS |
347 | #define LM75A_ID 0xA1 |
348 | ||
8ff69eeb | 349 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 350 | static int lm75_detect(struct i2c_client *new_client, |
8ff69eeb | 351 | struct i2c_board_info *info) |
1da177e4 | 352 | { |
8ff69eeb | 353 | struct i2c_adapter *adapter = new_client->adapter; |
1da177e4 | 354 | int i; |
e76f67b5 | 355 | int conf, hyst, os; |
05e82fe4 | 356 | bool is_lm75a = 0; |
1da177e4 | 357 | |
1da177e4 LT |
358 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
359 | I2C_FUNC_SMBUS_WORD_DATA)) | |
8ff69eeb | 360 | return -ENODEV; |
1da177e4 | 361 | |
426343ef JD |
362 | /* |
363 | * Now, we do the remaining detection. There is no identification- | |
364 | * dedicated register so we have to rely on several tricks: | |
365 | * unused bits, registers cycling over 8-address boundaries, | |
366 | * addresses 0x04-0x07 returning the last read value. | |
367 | * The cycling+unused addresses combination is not tested, | |
368 | * since it would significantly slow the detection down and would | |
369 | * hardly add any value. | |
370 | * | |
371 | * The National Semiconductor LM75A is different than earlier | |
372 | * LM75s. It has an ID byte of 0xaX (where X is the chip | |
373 | * revision, with 1 being the only revision in existence) in | |
374 | * register 7, and unused registers return 0xff rather than the | |
375 | * last read value. | |
376 | * | |
377 | * Note that this function only detects the original National | |
378 | * Semiconductor LM75 and the LM75A. Clones from other vendors | |
379 | * aren't detected, on purpose, because they are typically never | |
380 | * found on PC hardware. They are found on embedded designs where | |
381 | * they can be instantiated explicitly so detection is not needed. | |
382 | * The absence of identification registers on all these clones | |
383 | * would make their exhaustive detection very difficult and weak, | |
384 | * and odds are that the driver would bind to unsupported devices. | |
385 | */ | |
1da177e4 | 386 | |
e76f67b5 | 387 | /* Unused bits */ |
52df6440 | 388 | conf = i2c_smbus_read_byte_data(new_client, 1); |
e76f67b5 JD |
389 | if (conf & 0xe0) |
390 | return -ENODEV; | |
05e82fe4 LS |
391 | |
392 | /* First check for LM75A */ | |
393 | if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) { | |
394 | /* LM75A returns 0xff on unused registers so | |
395 | just to be sure we check for that too. */ | |
396 | if (i2c_smbus_read_byte_data(new_client, 4) != 0xff | |
397 | || i2c_smbus_read_byte_data(new_client, 5) != 0xff | |
398 | || i2c_smbus_read_byte_data(new_client, 6) != 0xff) | |
399 | return -ENODEV; | |
400 | is_lm75a = 1; | |
e76f67b5 JD |
401 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
402 | os = i2c_smbus_read_byte_data(new_client, 3); | |
05e82fe4 LS |
403 | } else { /* Traditional style LM75 detection */ |
404 | /* Unused addresses */ | |
e76f67b5 JD |
405 | hyst = i2c_smbus_read_byte_data(new_client, 2); |
406 | if (i2c_smbus_read_byte_data(new_client, 4) != hyst | |
407 | || i2c_smbus_read_byte_data(new_client, 5) != hyst | |
408 | || i2c_smbus_read_byte_data(new_client, 6) != hyst | |
409 | || i2c_smbus_read_byte_data(new_client, 7) != hyst) | |
05e82fe4 | 410 | return -ENODEV; |
e76f67b5 JD |
411 | os = i2c_smbus_read_byte_data(new_client, 3); |
412 | if (i2c_smbus_read_byte_data(new_client, 4) != os | |
413 | || i2c_smbus_read_byte_data(new_client, 5) != os | |
414 | || i2c_smbus_read_byte_data(new_client, 6) != os | |
415 | || i2c_smbus_read_byte_data(new_client, 7) != os) | |
05e82fe4 LS |
416 | return -ENODEV; |
417 | } | |
1da177e4 | 418 | |
52df6440 | 419 | /* Addresses cycling */ |
e76f67b5 | 420 | for (i = 8; i <= 248; i += 40) { |
52df6440 | 421 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf |
e76f67b5 JD |
422 | || i2c_smbus_read_byte_data(new_client, i + 2) != hyst |
423 | || i2c_smbus_read_byte_data(new_client, i + 3) != os) | |
52df6440 | 424 | return -ENODEV; |
05e82fe4 LS |
425 | if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7) |
426 | != LM75A_ID) | |
427 | return -ENODEV; | |
1da177e4 LT |
428 | } |
429 | ||
05e82fe4 | 430 | strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE); |
c1685f61 | 431 | |
1da177e4 | 432 | return 0; |
01a52397 DB |
433 | } |
434 | ||
9914518e SD |
435 | #ifdef CONFIG_PM |
436 | static int lm75_suspend(struct device *dev) | |
437 | { | |
438 | int status; | |
439 | struct i2c_client *client = to_i2c_client(dev); | |
440 | status = lm75_read_value(client, LM75_REG_CONF); | |
441 | if (status < 0) { | |
442 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
443 | return status; | |
444 | } | |
445 | status = status | LM75_SHUTDOWN; | |
446 | lm75_write_value(client, LM75_REG_CONF, status); | |
447 | return 0; | |
448 | } | |
449 | ||
450 | static int lm75_resume(struct device *dev) | |
451 | { | |
452 | int status; | |
453 | struct i2c_client *client = to_i2c_client(dev); | |
454 | status = lm75_read_value(client, LM75_REG_CONF); | |
455 | if (status < 0) { | |
456 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
457 | return status; | |
458 | } | |
459 | status = status & ~LM75_SHUTDOWN; | |
460 | lm75_write_value(client, LM75_REG_CONF, status); | |
461 | return 0; | |
462 | } | |
463 | ||
464 | static const struct dev_pm_ops lm75_dev_pm_ops = { | |
465 | .suspend = lm75_suspend, | |
466 | .resume = lm75_resume, | |
467 | }; | |
468 | #define LM75_DEV_PM_OPS (&lm75_dev_pm_ops) | |
469 | #else | |
470 | #define LM75_DEV_PM_OPS NULL | |
471 | #endif /* CONFIG_PM */ | |
472 | ||
8ff69eeb JD |
473 | static struct i2c_driver lm75_driver = { |
474 | .class = I2C_CLASS_HWMON, | |
01a52397 | 475 | .driver = { |
8ff69eeb | 476 | .name = "lm75", |
9914518e | 477 | .pm = LM75_DEV_PM_OPS, |
01a52397 | 478 | }, |
8ff69eeb JD |
479 | .probe = lm75_probe, |
480 | .remove = lm75_remove, | |
481 | .id_table = lm75_ids, | |
482 | .detect = lm75_detect, | |
c3813d6a | 483 | .address_list = normal_i2c, |
01a52397 DB |
484 | }; |
485 | ||
486 | /*-----------------------------------------------------------------------*/ | |
487 | ||
488 | /* register access */ | |
489 | ||
caaa0f36 S |
490 | /* |
491 | * All registers are word-sized, except for the configuration register. | |
492 | * LM75 uses a high-byte first convention, which is exactly opposite to | |
493 | * the SMBus standard. | |
494 | */ | |
1da177e4 LT |
495 | static int lm75_read_value(struct i2c_client *client, u8 reg) |
496 | { | |
497 | if (reg == LM75_REG_CONF) | |
498 | return i2c_smbus_read_byte_data(client, reg); | |
90f4102c JD |
499 | else |
500 | return i2c_smbus_read_word_swapped(client, reg); | |
1da177e4 LT |
501 | } |
502 | ||
1da177e4 LT |
503 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) |
504 | { | |
505 | if (reg == LM75_REG_CONF) | |
506 | return i2c_smbus_write_byte_data(client, reg, value); | |
507 | else | |
90f4102c | 508 | return i2c_smbus_write_word_swapped(client, reg, value); |
1da177e4 LT |
509 | } |
510 | ||
1da177e4 LT |
511 | static struct lm75_data *lm75_update_device(struct device *dev) |
512 | { | |
d663ec49 GR |
513 | struct lm75_data *data = dev_get_drvdata(dev); |
514 | struct i2c_client *client = data->client; | |
1f962f36 | 515 | struct lm75_data *ret = data; |
1da177e4 | 516 | |
9a61bf63 | 517 | mutex_lock(&data->update_lock); |
1da177e4 | 518 | |
87d0621a | 519 | if (time_after(jiffies, data->last_updated + data->sample_time) |
1da177e4 | 520 | || !data->valid) { |
9ca8e40c | 521 | int i; |
1da177e4 LT |
522 | dev_dbg(&client->dev, "Starting lm75 update\n"); |
523 | ||
bcccc3a2 DB |
524 | for (i = 0; i < ARRAY_SIZE(data->temp); i++) { |
525 | int status; | |
526 | ||
527 | status = lm75_read_value(client, LM75_REG_TEMP[i]); | |
1f962f36 FM |
528 | if (unlikely(status < 0)) { |
529 | dev_dbg(dev, | |
530 | "LM75: Failed to read value: reg %d, error %d\n", | |
531 | LM75_REG_TEMP[i], status); | |
532 | ret = ERR_PTR(status); | |
533 | data->valid = 0; | |
534 | goto abort; | |
535 | } | |
536 | data->temp[i] = status; | |
bcccc3a2 | 537 | } |
1da177e4 LT |
538 | data->last_updated = jiffies; |
539 | data->valid = 1; | |
540 | } | |
541 | ||
1f962f36 | 542 | abort: |
9a61bf63 | 543 | mutex_unlock(&data->update_lock); |
1f962f36 | 544 | return ret; |
1da177e4 LT |
545 | } |
546 | ||
f0967eea | 547 | module_i2c_driver(lm75_driver); |
1da177e4 LT |
548 | |
549 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); | |
550 | MODULE_DESCRIPTION("LM75 driver"); | |
551 | MODULE_LICENSE("GPL"); |