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1/*
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 */
20
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>
26#include <linux/hwmon.h>
27#include <linux/hwmon-sysfs.h>
28#include <linux/err.h>
29#include <linux/of.h>
30#include <linux/regmap.h>
31#include "lm75.h"
32
33
34/*
35 * This driver handles the LM75 and compatible digital temperature sensors.
36 */
37
38enum lm75_type { /* keep sorted in alphabetical order */
39 adt75,
40 ds1775,
41 ds75,
42 ds7505,
43 g751,
44 lm75,
45 lm75a,
46 lm75b,
47 max6625,
48 max6626,
49 mcp980x,
50 stds75,
51 tcn75,
52 tmp100,
53 tmp101,
54 tmp105,
55 tmp112,
56 tmp175,
57 tmp275,
58 tmp75,
59 tmp75c,
60};
61
62/* Addresses scanned */
63static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
64 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
65
66
67/* The LM75 registers */
68#define LM75_REG_TEMP 0x00
69#define LM75_REG_CONF 0x01
70#define LM75_REG_HYST 0x02
71#define LM75_REG_MAX 0x03
72
73/* Each client has this additional data */
74struct lm75_data {
75 struct i2c_client *client;
76 struct regmap *regmap;
77 u8 orig_conf;
78 u8 resolution; /* In bits, between 9 and 12 */
79 u8 resolution_limits;
80 unsigned int sample_time; /* In ms */
81};
82
83/*-----------------------------------------------------------------------*/
84
85static inline long lm75_reg_to_mc(s16 temp, u8 resolution)
86{
87 return ((temp >> (16 - resolution)) * 1000) >> (resolution - 8);
88}
89
90static int lm75_read(struct device *dev, enum hwmon_sensor_types type,
91 u32 attr, int channel, long *val)
92{
93 struct lm75_data *data = dev_get_drvdata(dev);
94 unsigned int regval;
95 int err, reg;
96
97 switch (type) {
98 case hwmon_chip:
99 switch (attr) {
100 case hwmon_chip_update_interval:
101 *val = data->sample_time;
102 break;;
103 default:
104 return -EINVAL;
105 }
106 break;
107 case hwmon_temp:
108 switch (attr) {
109 case hwmon_temp_input:
110 reg = LM75_REG_TEMP;
111 break;
112 case hwmon_temp_max:
113 reg = LM75_REG_MAX;
114 break;
115 case hwmon_temp_max_hyst:
116 reg = LM75_REG_HYST;
117 break;
118 default:
119 return -EINVAL;
120 }
121 err = regmap_read(data->regmap, reg, ®val);
122 if (err < 0)
123 return err;
124
125 *val = lm75_reg_to_mc(regval, data->resolution);
126 break;
127 default:
128 return -EINVAL;
129 }
130 return 0;
131}
132
133static int lm75_write(struct device *dev, enum hwmon_sensor_types type,
134 u32 attr, int channel, long temp)
135{
136 struct lm75_data *data = dev_get_drvdata(dev);
137 u8 resolution;
138 int reg;
139
140 if (type != hwmon_temp)
141 return -EINVAL;
142
143 switch (attr) {
144 case hwmon_temp_max:
145 reg = LM75_REG_MAX;
146 break;
147 case hwmon_temp_max_hyst:
148 reg = LM75_REG_HYST;
149 break;
150 default:
151 return -EINVAL;
152 }
153
154 /*
155 * Resolution of limit registers is assumed to be the same as the
156 * temperature input register resolution unless given explicitly.
157 */
158 if (data->resolution_limits)
159 resolution = data->resolution_limits;
160 else
161 resolution = data->resolution;
162
163 temp = clamp_val(temp, LM75_TEMP_MIN, LM75_TEMP_MAX);
164 temp = DIV_ROUND_CLOSEST(temp << (resolution - 8),
165 1000) << (16 - resolution);
166
167 return regmap_write(data->regmap, reg, temp);
168}
169
170static umode_t lm75_is_visible(const void *data, enum hwmon_sensor_types type,
171 u32 attr, int channel)
172{
173 switch (type) {
174 case hwmon_chip:
175 switch (attr) {
176 case hwmon_chip_update_interval:
177 return S_IRUGO;
178 }
179 break;
180 case hwmon_temp:
181 switch (attr) {
182 case hwmon_temp_input:
183 return S_IRUGO;
184 case hwmon_temp_max:
185 case hwmon_temp_max_hyst:
186 return S_IRUGO | S_IWUSR;
187 }
188 break;
189 default:
190 break;
191 }
192 return 0;
193}
194
195/*-----------------------------------------------------------------------*/
196
197/* device probe and removal */
198
199/* chip configuration */
200
201static const u32 lm75_chip_config[] = {
202 HWMON_C_REGISTER_TZ | HWMON_C_UPDATE_INTERVAL,
203 0
204};
205
206static const struct hwmon_channel_info lm75_chip = {
207 .type = hwmon_chip,
208 .config = lm75_chip_config,
209};
210
211static const u32 lm75_temp_config[] = {
212 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MAX_HYST,
213 0
214};
215
216static const struct hwmon_channel_info lm75_temp = {
217 .type = hwmon_temp,
218 .config = lm75_temp_config,
219};
220
221static const struct hwmon_channel_info *lm75_info[] = {
222 &lm75_chip,
223 &lm75_temp,
224 NULL
225};
226
227static const struct hwmon_ops lm75_hwmon_ops = {
228 .is_visible = lm75_is_visible,
229 .read = lm75_read,
230 .write = lm75_write,
231};
232
233static const struct hwmon_chip_info lm75_chip_info = {
234 .ops = &lm75_hwmon_ops,
235 .info = lm75_info,
236};
237
238static bool lm75_is_writeable_reg(struct device *dev, unsigned int reg)
239{
240 return reg != LM75_REG_TEMP;
241}
242
243static bool lm75_is_volatile_reg(struct device *dev, unsigned int reg)
244{
245 return reg == LM75_REG_TEMP;
246}
247
248static const struct regmap_config lm75_regmap_config = {
249 .reg_bits = 8,
250 .val_bits = 16,
251 .max_register = LM75_REG_MAX,
252 .writeable_reg = lm75_is_writeable_reg,
253 .volatile_reg = lm75_is_volatile_reg,
254 .val_format_endian = REGMAP_ENDIAN_BIG,
255 .cache_type = REGCACHE_RBTREE,
256 .use_single_rw = true,
257};
258
259static void lm75_remove(void *data)
260{
261 struct lm75_data *lm75 = data;
262 struct i2c_client *client = lm75->client;
263
264 i2c_smbus_write_byte_data(client, LM75_REG_CONF, lm75->orig_conf);
265}
266
267static int
268lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
269{
270 struct device *dev = &client->dev;
271 struct device *hwmon_dev;
272 struct lm75_data *data;
273 int status, err;
274 u8 set_mask, clr_mask;
275 int new;
276 enum lm75_type kind = id->driver_data;
277
278 if (!i2c_check_functionality(client->adapter,
279 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
280 return -EIO;
281
282 data = devm_kzalloc(dev, sizeof(struct lm75_data), GFP_KERNEL);
283 if (!data)
284 return -ENOMEM;
285
286 data->client = client;
287
288 data->regmap = devm_regmap_init_i2c(client, &lm75_regmap_config);
289 if (IS_ERR(data->regmap))
290 return PTR_ERR(data->regmap);
291
292 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
293 * Then tweak to be more precise when appropriate.
294 */
295 set_mask = 0;
296 clr_mask = LM75_SHUTDOWN; /* continuous conversions */
297
298 switch (kind) {
299 case adt75:
300 clr_mask |= 1 << 5; /* not one-shot mode */
301 data->resolution = 12;
302 data->sample_time = MSEC_PER_SEC / 8;
303 break;
304 case ds1775:
305 case ds75:
306 case stds75:
307 clr_mask |= 3 << 5;
308 set_mask |= 2 << 5; /* 11-bit mode */
309 data->resolution = 11;
310 data->sample_time = MSEC_PER_SEC;
311 break;
312 case ds7505:
313 set_mask |= 3 << 5; /* 12-bit mode */
314 data->resolution = 12;
315 data->sample_time = MSEC_PER_SEC / 4;
316 break;
317 case g751:
318 case lm75:
319 case lm75a:
320 data->resolution = 9;
321 data->sample_time = MSEC_PER_SEC / 2;
322 break;
323 case lm75b:
324 data->resolution = 11;
325 data->sample_time = MSEC_PER_SEC / 4;
326 break;
327 case max6625:
328 data->resolution = 9;
329 data->sample_time = MSEC_PER_SEC / 4;
330 break;
331 case max6626:
332 data->resolution = 12;
333 data->resolution_limits = 9;
334 data->sample_time = MSEC_PER_SEC / 4;
335 break;
336 case tcn75:
337 data->resolution = 9;
338 data->sample_time = MSEC_PER_SEC / 8;
339 break;
340 case mcp980x:
341 data->resolution_limits = 9;
342 /* fall through */
343 case tmp100:
344 case tmp101:
345 set_mask |= 3 << 5; /* 12-bit mode */
346 data->resolution = 12;
347 data->sample_time = MSEC_PER_SEC;
348 clr_mask |= 1 << 7; /* not one-shot mode */
349 break;
350 case tmp112:
351 set_mask |= 3 << 5; /* 12-bit mode */
352 clr_mask |= 1 << 7; /* not one-shot mode */
353 data->resolution = 12;
354 data->sample_time = MSEC_PER_SEC / 4;
355 break;
356 case tmp105:
357 case tmp175:
358 case tmp275:
359 case tmp75:
360 set_mask |= 3 << 5; /* 12-bit mode */
361 clr_mask |= 1 << 7; /* not one-shot mode */
362 data->resolution = 12;
363 data->sample_time = MSEC_PER_SEC / 2;
364 break;
365 case tmp75c:
366 clr_mask |= 1 << 5; /* not one-shot mode */
367 data->resolution = 12;
368 data->sample_time = MSEC_PER_SEC / 4;
369 break;
370 }
371
372 /* configure as specified */
373 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
374 if (status < 0) {
375 dev_dbg(dev, "Can't read config? %d\n", status);
376 return status;
377 }
378 data->orig_conf = status;
379 new = status & ~clr_mask;
380 new |= set_mask;
381 if (status != new)
382 i2c_smbus_write_byte_data(client, LM75_REG_CONF, new);
383
384 err = devm_add_action_or_reset(dev, lm75_remove, data);
385 if (err)
386 return err;
387
388 dev_dbg(dev, "Config %02x\n", new);
389
390 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
391 data, &lm75_chip_info,
392 NULL);
393 if (IS_ERR(hwmon_dev))
394 return PTR_ERR(hwmon_dev);
395
396 dev_info(dev, "%s: sensor '%s'\n", dev_name(hwmon_dev), client->name);
397
398 return 0;
399}
400
401static const struct i2c_device_id lm75_ids[] = {
402 { "adt75", adt75, },
403 { "ds1775", ds1775, },
404 { "ds75", ds75, },
405 { "ds7505", ds7505, },
406 { "g751", g751, },
407 { "lm75", lm75, },
408 { "lm75a", lm75a, },
409 { "lm75b", lm75b, },
410 { "max6625", max6625, },
411 { "max6626", max6626, },
412 { "mcp980x", mcp980x, },
413 { "stds75", stds75, },
414 { "tcn75", tcn75, },
415 { "tmp100", tmp100, },
416 { "tmp101", tmp101, },
417 { "tmp105", tmp105, },
418 { "tmp112", tmp112, },
419 { "tmp175", tmp175, },
420 { "tmp275", tmp275, },
421 { "tmp75", tmp75, },
422 { "tmp75c", tmp75c, },
423 { /* LIST END */ }
424};
425MODULE_DEVICE_TABLE(i2c, lm75_ids);
426
427#define LM75A_ID 0xA1
428
429/* Return 0 if detection is successful, -ENODEV otherwise */
430static int lm75_detect(struct i2c_client *new_client,
431 struct i2c_board_info *info)
432{
433 struct i2c_adapter *adapter = new_client->adapter;
434 int i;
435 int conf, hyst, os;
436 bool is_lm75a = 0;
437
438 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
439 I2C_FUNC_SMBUS_WORD_DATA))
440 return -ENODEV;
441
442 /*
443 * Now, we do the remaining detection. There is no identification-
444 * dedicated register so we have to rely on several tricks:
445 * unused bits, registers cycling over 8-address boundaries,
446 * addresses 0x04-0x07 returning the last read value.
447 * The cycling+unused addresses combination is not tested,
448 * since it would significantly slow the detection down and would
449 * hardly add any value.
450 *
451 * The National Semiconductor LM75A is different than earlier
452 * LM75s. It has an ID byte of 0xaX (where X is the chip
453 * revision, with 1 being the only revision in existence) in
454 * register 7, and unused registers return 0xff rather than the
455 * last read value.
456 *
457 * Note that this function only detects the original National
458 * Semiconductor LM75 and the LM75A. Clones from other vendors
459 * aren't detected, on purpose, because they are typically never
460 * found on PC hardware. They are found on embedded designs where
461 * they can be instantiated explicitly so detection is not needed.
462 * The absence of identification registers on all these clones
463 * would make their exhaustive detection very difficult and weak,
464 * and odds are that the driver would bind to unsupported devices.
465 */
466
467 /* Unused bits */
468 conf = i2c_smbus_read_byte_data(new_client, 1);
469 if (conf & 0xe0)
470 return -ENODEV;
471
472 /* First check for LM75A */
473 if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
474 /* LM75A returns 0xff on unused registers so
475 just to be sure we check for that too. */
476 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
477 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
478 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
479 return -ENODEV;
480 is_lm75a = 1;
481 hyst = i2c_smbus_read_byte_data(new_client, 2);
482 os = i2c_smbus_read_byte_data(new_client, 3);
483 } else { /* Traditional style LM75 detection */
484 /* Unused addresses */
485 hyst = i2c_smbus_read_byte_data(new_client, 2);
486 if (i2c_smbus_read_byte_data(new_client, 4) != hyst
487 || i2c_smbus_read_byte_data(new_client, 5) != hyst
488 || i2c_smbus_read_byte_data(new_client, 6) != hyst
489 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
490 return -ENODEV;
491 os = i2c_smbus_read_byte_data(new_client, 3);
492 if (i2c_smbus_read_byte_data(new_client, 4) != os
493 || i2c_smbus_read_byte_data(new_client, 5) != os
494 || i2c_smbus_read_byte_data(new_client, 6) != os
495 || i2c_smbus_read_byte_data(new_client, 7) != os)
496 return -ENODEV;
497 }
498 /*
499 * It is very unlikely that this is a LM75 if both
500 * hysteresis and temperature limit registers are 0.
501 */
502 if (hyst == 0 && os == 0)
503 return -ENODEV;
504
505 /* Addresses cycling */
506 for (i = 8; i <= 248; i += 40) {
507 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
508 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
509 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
510 return -ENODEV;
511 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
512 != LM75A_ID)
513 return -ENODEV;
514 }
515
516 strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
517
518 return 0;
519}
520
521#ifdef CONFIG_PM
522static int lm75_suspend(struct device *dev)
523{
524 int status;
525 struct i2c_client *client = to_i2c_client(dev);
526 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
527 if (status < 0) {
528 dev_dbg(&client->dev, "Can't read config? %d\n", status);
529 return status;
530 }
531 status = status | LM75_SHUTDOWN;
532 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
533 return 0;
534}
535
536static int lm75_resume(struct device *dev)
537{
538 int status;
539 struct i2c_client *client = to_i2c_client(dev);
540 status = i2c_smbus_read_byte_data(client, LM75_REG_CONF);
541 if (status < 0) {
542 dev_dbg(&client->dev, "Can't read config? %d\n", status);
543 return status;
544 }
545 status = status & ~LM75_SHUTDOWN;
546 i2c_smbus_write_byte_data(client, LM75_REG_CONF, status);
547 return 0;
548}
549
550static const struct dev_pm_ops lm75_dev_pm_ops = {
551 .suspend = lm75_suspend,
552 .resume = lm75_resume,
553};
554#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
555#else
556#define LM75_DEV_PM_OPS NULL
557#endif /* CONFIG_PM */
558
559static struct i2c_driver lm75_driver = {
560 .class = I2C_CLASS_HWMON,
561 .driver = {
562 .name = "lm75",
563 .pm = LM75_DEV_PM_OPS,
564 },
565 .probe = lm75_probe,
566 .id_table = lm75_ids,
567 .detect = lm75_detect,
568 .address_list = normal_i2c,
569};
570
571module_i2c_driver(lm75_driver);
572
573MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
574MODULE_DESCRIPTION("LM75 driver");
575MODULE_LICENSE("GPL");
1/*
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 */
20
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>
26#include <linux/hwmon.h>
27#include <linux/hwmon-sysfs.h>
28#include <linux/err.h>
29#include <linux/mutex.h>
30#include "lm75.h"
31
32
33/*
34 * This driver handles the LM75 and compatible digital temperature sensors.
35 */
36
37enum lm75_type { /* keep sorted in alphabetical order */
38 adt75,
39 ds1775,
40 ds75,
41 lm75,
42 lm75a,
43 max6625,
44 max6626,
45 mcp980x,
46 stds75,
47 tcn75,
48 tmp100,
49 tmp101,
50 tmp105,
51 tmp175,
52 tmp275,
53 tmp75,
54};
55
56/* Addresses scanned */
57static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
58 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
59
60
61/* The LM75 registers */
62#define LM75_REG_CONF 0x01
63static const u8 LM75_REG_TEMP[3] = {
64 0x00, /* input */
65 0x03, /* max */
66 0x02, /* hyst */
67};
68
69/* Each client has this additional data */
70struct lm75_data {
71 struct device *hwmon_dev;
72 struct mutex update_lock;
73 u8 orig_conf;
74 char valid; /* !=0 if registers are valid */
75 unsigned long last_updated; /* In jiffies */
76 u16 temp[3]; /* Register values,
77 0 = input
78 1 = max
79 2 = hyst */
80};
81
82static int lm75_read_value(struct i2c_client *client, u8 reg);
83static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value);
84static struct lm75_data *lm75_update_device(struct device *dev);
85
86
87/*-----------------------------------------------------------------------*/
88
89/* sysfs attributes for hwmon */
90
91static ssize_t show_temp(struct device *dev, struct device_attribute *da,
92 char *buf)
93{
94 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
95 struct lm75_data *data = lm75_update_device(dev);
96
97 if (IS_ERR(data))
98 return PTR_ERR(data);
99
100 return sprintf(buf, "%d\n",
101 LM75_TEMP_FROM_REG(data->temp[attr->index]));
102}
103
104static ssize_t set_temp(struct device *dev, struct device_attribute *da,
105 const char *buf, size_t count)
106{
107 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
108 struct i2c_client *client = to_i2c_client(dev);
109 struct lm75_data *data = i2c_get_clientdata(client);
110 int nr = attr->index;
111 long temp;
112 int error;
113
114 error = kstrtol(buf, 10, &temp);
115 if (error)
116 return error;
117
118 mutex_lock(&data->update_lock);
119 data->temp[nr] = LM75_TEMP_TO_REG(temp);
120 lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]);
121 mutex_unlock(&data->update_lock);
122 return count;
123}
124
125static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
126 show_temp, set_temp, 1);
127static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
128 show_temp, set_temp, 2);
129static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
130
131static struct attribute *lm75_attributes[] = {
132 &sensor_dev_attr_temp1_input.dev_attr.attr,
133 &sensor_dev_attr_temp1_max.dev_attr.attr,
134 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
135
136 NULL
137};
138
139static const struct attribute_group lm75_group = {
140 .attrs = lm75_attributes,
141};
142
143/*-----------------------------------------------------------------------*/
144
145/* device probe and removal */
146
147static int
148lm75_probe(struct i2c_client *client, const struct i2c_device_id *id)
149{
150 struct lm75_data *data;
151 int status;
152 u8 set_mask, clr_mask;
153 int new;
154
155 if (!i2c_check_functionality(client->adapter,
156 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
157 return -EIO;
158
159 data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL);
160 if (!data)
161 return -ENOMEM;
162
163 i2c_set_clientdata(client, data);
164 mutex_init(&data->update_lock);
165
166 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
167 * Then tweak to be more precise when appropriate.
168 */
169 set_mask = 0;
170 clr_mask = (1 << 0) /* continuous conversions */
171 | (1 << 6) | (1 << 5); /* 9-bit mode */
172
173 /* configure as specified */
174 status = lm75_read_value(client, LM75_REG_CONF);
175 if (status < 0) {
176 dev_dbg(&client->dev, "Can't read config? %d\n", status);
177 goto exit_free;
178 }
179 data->orig_conf = status;
180 new = status & ~clr_mask;
181 new |= set_mask;
182 if (status != new)
183 lm75_write_value(client, LM75_REG_CONF, new);
184 dev_dbg(&client->dev, "Config %02x\n", new);
185
186 /* Register sysfs hooks */
187 status = sysfs_create_group(&client->dev.kobj, &lm75_group);
188 if (status)
189 goto exit_free;
190
191 data->hwmon_dev = hwmon_device_register(&client->dev);
192 if (IS_ERR(data->hwmon_dev)) {
193 status = PTR_ERR(data->hwmon_dev);
194 goto exit_remove;
195 }
196
197 dev_info(&client->dev, "%s: sensor '%s'\n",
198 dev_name(data->hwmon_dev), client->name);
199
200 return 0;
201
202exit_remove:
203 sysfs_remove_group(&client->dev.kobj, &lm75_group);
204exit_free:
205 kfree(data);
206 return status;
207}
208
209static int lm75_remove(struct i2c_client *client)
210{
211 struct lm75_data *data = i2c_get_clientdata(client);
212
213 hwmon_device_unregister(data->hwmon_dev);
214 sysfs_remove_group(&client->dev.kobj, &lm75_group);
215 lm75_write_value(client, LM75_REG_CONF, data->orig_conf);
216 kfree(data);
217 return 0;
218}
219
220static const struct i2c_device_id lm75_ids[] = {
221 { "adt75", adt75, },
222 { "ds1775", ds1775, },
223 { "ds75", ds75, },
224 { "lm75", lm75, },
225 { "lm75a", lm75a, },
226 { "max6625", max6625, },
227 { "max6626", max6626, },
228 { "mcp980x", mcp980x, },
229 { "stds75", stds75, },
230 { "tcn75", tcn75, },
231 { "tmp100", tmp100, },
232 { "tmp101", tmp101, },
233 { "tmp105", tmp105, },
234 { "tmp175", tmp175, },
235 { "tmp275", tmp275, },
236 { "tmp75", tmp75, },
237 { /* LIST END */ }
238};
239MODULE_DEVICE_TABLE(i2c, lm75_ids);
240
241#define LM75A_ID 0xA1
242
243/* Return 0 if detection is successful, -ENODEV otherwise */
244static int lm75_detect(struct i2c_client *new_client,
245 struct i2c_board_info *info)
246{
247 struct i2c_adapter *adapter = new_client->adapter;
248 int i;
249 int conf, hyst, os;
250 bool is_lm75a = 0;
251
252 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
253 I2C_FUNC_SMBUS_WORD_DATA))
254 return -ENODEV;
255
256 /*
257 * Now, we do the remaining detection. There is no identification-
258 * dedicated register so we have to rely on several tricks:
259 * unused bits, registers cycling over 8-address boundaries,
260 * addresses 0x04-0x07 returning the last read value.
261 * The cycling+unused addresses combination is not tested,
262 * since it would significantly slow the detection down and would
263 * hardly add any value.
264 *
265 * The National Semiconductor LM75A is different than earlier
266 * LM75s. It has an ID byte of 0xaX (where X is the chip
267 * revision, with 1 being the only revision in existence) in
268 * register 7, and unused registers return 0xff rather than the
269 * last read value.
270 *
271 * Note that this function only detects the original National
272 * Semiconductor LM75 and the LM75A. Clones from other vendors
273 * aren't detected, on purpose, because they are typically never
274 * found on PC hardware. They are found on embedded designs where
275 * they can be instantiated explicitly so detection is not needed.
276 * The absence of identification registers on all these clones
277 * would make their exhaustive detection very difficult and weak,
278 * and odds are that the driver would bind to unsupported devices.
279 */
280
281 /* Unused bits */
282 conf = i2c_smbus_read_byte_data(new_client, 1);
283 if (conf & 0xe0)
284 return -ENODEV;
285
286 /* First check for LM75A */
287 if (i2c_smbus_read_byte_data(new_client, 7) == LM75A_ID) {
288 /* LM75A returns 0xff on unused registers so
289 just to be sure we check for that too. */
290 if (i2c_smbus_read_byte_data(new_client, 4) != 0xff
291 || i2c_smbus_read_byte_data(new_client, 5) != 0xff
292 || i2c_smbus_read_byte_data(new_client, 6) != 0xff)
293 return -ENODEV;
294 is_lm75a = 1;
295 hyst = i2c_smbus_read_byte_data(new_client, 2);
296 os = i2c_smbus_read_byte_data(new_client, 3);
297 } else { /* Traditional style LM75 detection */
298 /* Unused addresses */
299 hyst = i2c_smbus_read_byte_data(new_client, 2);
300 if (i2c_smbus_read_byte_data(new_client, 4) != hyst
301 || i2c_smbus_read_byte_data(new_client, 5) != hyst
302 || i2c_smbus_read_byte_data(new_client, 6) != hyst
303 || i2c_smbus_read_byte_data(new_client, 7) != hyst)
304 return -ENODEV;
305 os = i2c_smbus_read_byte_data(new_client, 3);
306 if (i2c_smbus_read_byte_data(new_client, 4) != os
307 || i2c_smbus_read_byte_data(new_client, 5) != os
308 || i2c_smbus_read_byte_data(new_client, 6) != os
309 || i2c_smbus_read_byte_data(new_client, 7) != os)
310 return -ENODEV;
311 }
312
313 /* Addresses cycling */
314 for (i = 8; i <= 248; i += 40) {
315 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
316 || i2c_smbus_read_byte_data(new_client, i + 2) != hyst
317 || i2c_smbus_read_byte_data(new_client, i + 3) != os)
318 return -ENODEV;
319 if (is_lm75a && i2c_smbus_read_byte_data(new_client, i + 7)
320 != LM75A_ID)
321 return -ENODEV;
322 }
323
324 strlcpy(info->type, is_lm75a ? "lm75a" : "lm75", I2C_NAME_SIZE);
325
326 return 0;
327}
328
329#ifdef CONFIG_PM
330static int lm75_suspend(struct device *dev)
331{
332 int status;
333 struct i2c_client *client = to_i2c_client(dev);
334 status = lm75_read_value(client, LM75_REG_CONF);
335 if (status < 0) {
336 dev_dbg(&client->dev, "Can't read config? %d\n", status);
337 return status;
338 }
339 status = status | LM75_SHUTDOWN;
340 lm75_write_value(client, LM75_REG_CONF, status);
341 return 0;
342}
343
344static int lm75_resume(struct device *dev)
345{
346 int status;
347 struct i2c_client *client = to_i2c_client(dev);
348 status = lm75_read_value(client, LM75_REG_CONF);
349 if (status < 0) {
350 dev_dbg(&client->dev, "Can't read config? %d\n", status);
351 return status;
352 }
353 status = status & ~LM75_SHUTDOWN;
354 lm75_write_value(client, LM75_REG_CONF, status);
355 return 0;
356}
357
358static const struct dev_pm_ops lm75_dev_pm_ops = {
359 .suspend = lm75_suspend,
360 .resume = lm75_resume,
361};
362#define LM75_DEV_PM_OPS (&lm75_dev_pm_ops)
363#else
364#define LM75_DEV_PM_OPS NULL
365#endif /* CONFIG_PM */
366
367static struct i2c_driver lm75_driver = {
368 .class = I2C_CLASS_HWMON,
369 .driver = {
370 .name = "lm75",
371 .pm = LM75_DEV_PM_OPS,
372 },
373 .probe = lm75_probe,
374 .remove = lm75_remove,
375 .id_table = lm75_ids,
376 .detect = lm75_detect,
377 .address_list = normal_i2c,
378};
379
380/*-----------------------------------------------------------------------*/
381
382/* register access */
383
384/*
385 * All registers are word-sized, except for the configuration register.
386 * LM75 uses a high-byte first convention, which is exactly opposite to
387 * the SMBus standard.
388 */
389static int lm75_read_value(struct i2c_client *client, u8 reg)
390{
391 if (reg == LM75_REG_CONF)
392 return i2c_smbus_read_byte_data(client, reg);
393 else
394 return i2c_smbus_read_word_swapped(client, reg);
395}
396
397static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value)
398{
399 if (reg == LM75_REG_CONF)
400 return i2c_smbus_write_byte_data(client, reg, value);
401 else
402 return i2c_smbus_write_word_swapped(client, reg, value);
403}
404
405static struct lm75_data *lm75_update_device(struct device *dev)
406{
407 struct i2c_client *client = to_i2c_client(dev);
408 struct lm75_data *data = i2c_get_clientdata(client);
409 struct lm75_data *ret = data;
410
411 mutex_lock(&data->update_lock);
412
413 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
414 || !data->valid) {
415 int i;
416 dev_dbg(&client->dev, "Starting lm75 update\n");
417
418 for (i = 0; i < ARRAY_SIZE(data->temp); i++) {
419 int status;
420
421 status = lm75_read_value(client, LM75_REG_TEMP[i]);
422 if (unlikely(status < 0)) {
423 dev_dbg(dev,
424 "LM75: Failed to read value: reg %d, error %d\n",
425 LM75_REG_TEMP[i], status);
426 ret = ERR_PTR(status);
427 data->valid = 0;
428 goto abort;
429 }
430 data->temp[i] = status;
431 }
432 data->last_updated = jiffies;
433 data->valid = 1;
434 }
435
436abort:
437 mutex_unlock(&data->update_lock);
438 return ret;
439}
440
441module_i2c_driver(lm75_driver);
442
443MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
444MODULE_DESCRIPTION("LM75 driver");
445MODULE_LICENSE("GPL");