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1da177e4 LT |
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 | ||
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> |
1da177e4 LT |
30 | #include "lm75.h" |
31 | ||
32 | ||
01a52397 DB |
33 | /* |
34 | * This driver handles the LM75 and compatible digital temperature sensors. | |
9ebd3d82 DB |
35 | * Only types which are _not_ listed in I2C_CLIENT_INSMOD_*() need to be |
36 | * listed here. We start at 9 since I2C_CLIENT_INSMOD_*() currently allow | |
37 | * definition of up to 8 chip types (plus zero). | |
01a52397 DB |
38 | */ |
39 | ||
9ebd3d82 DB |
40 | enum lm75_type { /* keep sorted in alphabetical order */ |
41 | ds1775 = 9, | |
42 | ds75, | |
43 | /* lm75 -- in I2C_CLIENT_INSMOD_1() */ | |
44 | lm75a, | |
45 | max6625, | |
46 | max6626, | |
47 | mcp980x, | |
48 | stds75, | |
49 | tcn75, | |
50 | tmp100, | |
51 | tmp101, | |
52 | tmp175, | |
53 | tmp275, | |
54 | tmp75, | |
55 | }; | |
56 | ||
8ff69eeb | 57 | /* Addresses scanned */ |
25e9c86d | 58 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, |
1da177e4 | 59 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; |
1da177e4 | 60 | |
8ff69eeb | 61 | /* Insmod parameters */ |
f4b50261 | 62 | I2C_CLIENT_INSMOD_1(lm75); |
1da177e4 | 63 | |
1da177e4 LT |
64 | |
65 | /* The LM75 registers */ | |
1da177e4 | 66 | #define LM75_REG_CONF 0x01 |
9ca8e40c JD |
67 | static const u8 LM75_REG_TEMP[3] = { |
68 | 0x00, /* input */ | |
69 | 0x03, /* max */ | |
70 | 0x02, /* hyst */ | |
71 | }; | |
1da177e4 LT |
72 | |
73 | /* Each client has this additional data */ | |
74 | struct lm75_data { | |
01a52397 | 75 | struct device *hwmon_dev; |
9a61bf63 | 76 | struct mutex update_lock; |
9ebd3d82 | 77 | u8 orig_conf; |
01a52397 | 78 | char valid; /* !=0 if registers are valid */ |
1da177e4 | 79 | unsigned long last_updated; /* In jiffies */ |
9ca8e40c JD |
80 | u16 temp[3]; /* Register values, |
81 | 0 = input | |
82 | 1 = max | |
83 | 2 = hyst */ | |
1da177e4 LT |
84 | }; |
85 | ||
1da177e4 LT |
86 | static int lm75_read_value(struct i2c_client *client, u8 reg); |
87 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); | |
88 | static struct lm75_data *lm75_update_device(struct device *dev); | |
89 | ||
90 | ||
01a52397 DB |
91 | /*-----------------------------------------------------------------------*/ |
92 | ||
93 | /* sysfs attributes for hwmon */ | |
1da177e4 | 94 | |
9ca8e40c JD |
95 | static ssize_t show_temp(struct device *dev, struct device_attribute *da, |
96 | char *buf) | |
97 | { | |
98 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
99 | struct lm75_data *data = lm75_update_device(dev); | |
100 | return sprintf(buf, "%d\n", | |
101 | LM75_TEMP_FROM_REG(data->temp[attr->index])); | |
1da177e4 | 102 | } |
9ca8e40c JD |
103 | |
104 | static 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; | |
5bfedac0 | 111 | long temp = simple_strtol(buf, NULL, 10); |
9ca8e40c JD |
112 | |
113 | mutex_lock(&data->update_lock); | |
114 | data->temp[nr] = LM75_TEMP_TO_REG(temp); | |
115 | lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]); | |
116 | mutex_unlock(&data->update_lock); | |
117 | return count; | |
1da177e4 | 118 | } |
1da177e4 | 119 | |
9ca8e40c JD |
120 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, |
121 | show_temp, set_temp, 1); | |
122 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, | |
123 | show_temp, set_temp, 2); | |
124 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); | |
1da177e4 | 125 | |
c1685f61 | 126 | static struct attribute *lm75_attributes[] = { |
9ca8e40c JD |
127 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
128 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
129 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
c1685f61 MH |
130 | |
131 | NULL | |
132 | }; | |
133 | ||
134 | static const struct attribute_group lm75_group = { | |
135 | .attrs = lm75_attributes, | |
136 | }; | |
137 | ||
01a52397 DB |
138 | /*-----------------------------------------------------------------------*/ |
139 | ||
8ff69eeb | 140 | /* device probe and removal */ |
9ebd3d82 DB |
141 | |
142 | static int | |
143 | lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) | |
144 | { | |
145 | struct lm75_data *data; | |
146 | int status; | |
147 | u8 set_mask, clr_mask; | |
148 | int new; | |
149 | ||
150 | if (!i2c_check_functionality(client->adapter, | |
151 | I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA)) | |
152 | return -EIO; | |
153 | ||
154 | data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL); | |
155 | if (!data) | |
156 | return -ENOMEM; | |
157 | ||
158 | i2c_set_clientdata(client, data); | |
9ebd3d82 DB |
159 | mutex_init(&data->update_lock); |
160 | ||
161 | /* Set to LM75 resolution (9 bits, 1/2 degree C) and range. | |
162 | * Then tweak to be more precise when appropriate. | |
163 | */ | |
164 | set_mask = 0; | |
165 | clr_mask = (1 << 0) /* continuous conversions */ | |
166 | | (1 << 6) | (1 << 5); /* 9-bit mode */ | |
167 | ||
168 | /* configure as specified */ | |
169 | status = lm75_read_value(client, LM75_REG_CONF); | |
170 | if (status < 0) { | |
171 | dev_dbg(&client->dev, "Can't read config? %d\n", status); | |
172 | goto exit_free; | |
173 | } | |
174 | data->orig_conf = status; | |
175 | new = status & ~clr_mask; | |
176 | new |= set_mask; | |
177 | if (status != new) | |
178 | lm75_write_value(client, LM75_REG_CONF, new); | |
179 | dev_dbg(&client->dev, "Config %02x\n", new); | |
180 | ||
181 | /* Register sysfs hooks */ | |
182 | status = sysfs_create_group(&client->dev.kobj, &lm75_group); | |
183 | if (status) | |
184 | goto exit_free; | |
185 | ||
186 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
187 | if (IS_ERR(data->hwmon_dev)) { | |
188 | status = PTR_ERR(data->hwmon_dev); | |
189 | goto exit_remove; | |
190 | } | |
191 | ||
192 | dev_info(&client->dev, "%s: sensor '%s'\n", | |
193 | data->hwmon_dev->bus_id, client->name); | |
194 | ||
195 | return 0; | |
196 | ||
197 | exit_remove: | |
198 | sysfs_remove_group(&client->dev.kobj, &lm75_group); | |
199 | exit_free: | |
200 | i2c_set_clientdata(client, NULL); | |
201 | kfree(data); | |
202 | return status; | |
203 | } | |
204 | ||
205 | static int lm75_remove(struct i2c_client *client) | |
206 | { | |
207 | struct lm75_data *data = i2c_get_clientdata(client); | |
208 | ||
209 | hwmon_device_unregister(data->hwmon_dev); | |
210 | sysfs_remove_group(&client->dev.kobj, &lm75_group); | |
211 | lm75_write_value(client, LM75_REG_CONF, data->orig_conf); | |
212 | i2c_set_clientdata(client, NULL); | |
213 | kfree(data); | |
214 | return 0; | |
215 | } | |
216 | ||
217 | static const struct i2c_device_id lm75_ids[] = { | |
218 | { "ds1775", ds1775, }, | |
219 | { "ds75", ds75, }, | |
220 | { "lm75", lm75, }, | |
221 | { "lm75a", lm75a, }, | |
222 | { "max6625", max6625, }, | |
223 | { "max6626", max6626, }, | |
224 | { "mcp980x", mcp980x, }, | |
225 | { "stds75", stds75, }, | |
226 | { "tcn75", tcn75, }, | |
227 | { "tmp100", tmp100, }, | |
228 | { "tmp101", tmp101, }, | |
229 | { "tmp175", tmp175, }, | |
230 | { "tmp275", tmp275, }, | |
231 | { "tmp75", tmp75, }, | |
232 | { /* LIST END */ } | |
233 | }; | |
234 | MODULE_DEVICE_TABLE(i2c, lm75_ids); | |
235 | ||
8ff69eeb JD |
236 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
237 | static int lm75_detect(struct i2c_client *new_client, int kind, | |
238 | struct i2c_board_info *info) | |
1da177e4 | 239 | { |
8ff69eeb | 240 | struct i2c_adapter *adapter = new_client->adapter; |
1da177e4 | 241 | int i; |
1da177e4 | 242 | |
1da177e4 LT |
243 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
244 | I2C_FUNC_SMBUS_WORD_DATA)) | |
8ff69eeb | 245 | return -ENODEV; |
1da177e4 LT |
246 | |
247 | /* Now, we do the remaining detection. There is no identification- | |
248 | dedicated register so we have to rely on several tricks: | |
249 | unused bits, registers cycling over 8-address boundaries, | |
250 | addresses 0x04-0x07 returning the last read value. | |
251 | The cycling+unused addresses combination is not tested, | |
252 | since it would significantly slow the detection down and would | |
253 | hardly add any value. */ | |
254 | if (kind < 0) { | |
255 | int cur, conf, hyst, os; | |
256 | ||
257 | /* Unused addresses */ | |
258 | cur = i2c_smbus_read_word_data(new_client, 0); | |
259 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
260 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
261 | if (i2c_smbus_read_word_data(new_client, 4) != hyst | |
262 | || i2c_smbus_read_word_data(new_client, 5) != hyst | |
263 | || i2c_smbus_read_word_data(new_client, 6) != hyst | |
264 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
8ff69eeb | 265 | return -ENODEV; |
1da177e4 LT |
266 | os = i2c_smbus_read_word_data(new_client, 3); |
267 | if (i2c_smbus_read_word_data(new_client, 4) != os | |
268 | || i2c_smbus_read_word_data(new_client, 5) != os | |
269 | || i2c_smbus_read_word_data(new_client, 6) != os | |
270 | || i2c_smbus_read_word_data(new_client, 7) != os) | |
8ff69eeb | 271 | return -ENODEV; |
1da177e4 LT |
272 | |
273 | /* Unused bits */ | |
274 | if (conf & 0xe0) | |
8ff69eeb | 275 | return -ENODEV; |
1da177e4 LT |
276 | |
277 | /* Addresses cycling */ | |
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) != os) | |
8ff69eeb | 282 | return -ENODEV; |
1da177e4 LT |
283 | } |
284 | ||
9ebd3d82 DB |
285 | /* NOTE: we treat "force=..." and "force_lm75=..." the same. |
286 | * Only new-style driver binding distinguishes chip types. | |
287 | */ | |
8ff69eeb | 288 | strlcpy(info->type, "lm75", I2C_NAME_SIZE); |
c1685f61 | 289 | |
1da177e4 | 290 | return 0; |
01a52397 DB |
291 | } |
292 | ||
8ff69eeb JD |
293 | static struct i2c_driver lm75_driver = { |
294 | .class = I2C_CLASS_HWMON, | |
01a52397 | 295 | .driver = { |
8ff69eeb | 296 | .name = "lm75", |
01a52397 | 297 | }, |
8ff69eeb JD |
298 | .probe = lm75_probe, |
299 | .remove = lm75_remove, | |
300 | .id_table = lm75_ids, | |
301 | .detect = lm75_detect, | |
302 | .address_data = &addr_data, | |
01a52397 DB |
303 | }; |
304 | ||
305 | /*-----------------------------------------------------------------------*/ | |
306 | ||
307 | /* register access */ | |
308 | ||
1da177e4 LT |
309 | /* All registers are word-sized, except for the configuration register. |
310 | LM75 uses a high-byte first convention, which is exactly opposite to | |
ccd6befc | 311 | the SMBus standard. */ |
1da177e4 LT |
312 | static int lm75_read_value(struct i2c_client *client, u8 reg) |
313 | { | |
bcccc3a2 DB |
314 | int value; |
315 | ||
1da177e4 LT |
316 | if (reg == LM75_REG_CONF) |
317 | return i2c_smbus_read_byte_data(client, reg); | |
bcccc3a2 DB |
318 | |
319 | value = i2c_smbus_read_word_data(client, reg); | |
320 | return (value < 0) ? value : swab16(value); | |
1da177e4 LT |
321 | } |
322 | ||
1da177e4 LT |
323 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) |
324 | { | |
325 | if (reg == LM75_REG_CONF) | |
326 | return i2c_smbus_write_byte_data(client, reg, value); | |
327 | else | |
328 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
329 | } | |
330 | ||
1da177e4 LT |
331 | static struct lm75_data *lm75_update_device(struct device *dev) |
332 | { | |
333 | struct i2c_client *client = to_i2c_client(dev); | |
334 | struct lm75_data *data = i2c_get_clientdata(client); | |
335 | ||
9a61bf63 | 336 | mutex_lock(&data->update_lock); |
1da177e4 LT |
337 | |
338 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
339 | || !data->valid) { | |
9ca8e40c | 340 | int i; |
1da177e4 LT |
341 | dev_dbg(&client->dev, "Starting lm75 update\n"); |
342 | ||
bcccc3a2 DB |
343 | for (i = 0; i < ARRAY_SIZE(data->temp); i++) { |
344 | int status; | |
345 | ||
346 | status = lm75_read_value(client, LM75_REG_TEMP[i]); | |
347 | if (status < 0) | |
348 | dev_dbg(&client->dev, "reg %d, err %d\n", | |
349 | LM75_REG_TEMP[i], status); | |
350 | else | |
351 | data->temp[i] = status; | |
352 | } | |
1da177e4 LT |
353 | data->last_updated = jiffies; |
354 | data->valid = 1; | |
355 | } | |
356 | ||
9a61bf63 | 357 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
358 | |
359 | return data; | |
360 | } | |
361 | ||
01a52397 DB |
362 | /*-----------------------------------------------------------------------*/ |
363 | ||
364 | /* module glue */ | |
365 | ||
1da177e4 LT |
366 | static int __init sensors_lm75_init(void) |
367 | { | |
8ff69eeb | 368 | return i2c_add_driver(&lm75_driver); |
1da177e4 LT |
369 | } |
370 | ||
371 | static void __exit sensors_lm75_exit(void) | |
372 | { | |
373 | i2c_del_driver(&lm75_driver); | |
374 | } | |
375 | ||
376 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); | |
377 | MODULE_DESCRIPTION("LM75 driver"); | |
378 | MODULE_LICENSE("GPL"); | |
379 | ||
380 | module_init(sensors_lm75_init); | |
381 | module_exit(sensors_lm75_exit); |