2 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
4 * The LM95241 is a sensor chip made by National Semiconductors.
5 * It reports up to three temperatures (its own plus up to two external ones).
6 * Complete datasheet can be obtained from National's website at:
7 * http://www.national.com/ds.cgi/LM/LM95241.pdf
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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>
29 #include <linux/hwmon.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 #include <linux/sysfs.h>
35 #define DEVNAME "lm95241"
37 static const unsigned short normal_i2c[] = {
38 0x19, 0x2a, 0x2b, I2C_CLIENT_END };
40 /* LM95241 registers */
41 #define LM95241_REG_R_MAN_ID 0xFE
42 #define LM95241_REG_R_CHIP_ID 0xFF
43 #define LM95241_REG_R_STATUS 0x02
44 #define LM95241_REG_RW_CONFIG 0x03
45 #define LM95241_REG_RW_REM_FILTER 0x06
46 #define LM95241_REG_RW_TRUTHERM 0x07
47 #define LM95241_REG_W_ONE_SHOT 0x0F
48 #define LM95241_REG_R_LOCAL_TEMPH 0x10
49 #define LM95241_REG_R_REMOTE1_TEMPH 0x11
50 #define LM95241_REG_R_REMOTE2_TEMPH 0x12
51 #define LM95241_REG_R_LOCAL_TEMPL 0x20
52 #define LM95241_REG_R_REMOTE1_TEMPL 0x21
53 #define LM95241_REG_R_REMOTE2_TEMPL 0x22
54 #define LM95241_REG_RW_REMOTE_MODEL 0x30
56 /* LM95241 specific bitfields */
58 #define CFG_CR0076 0x00
59 #define CFG_CR0182 0x10
60 #define CFG_CR1000 0x20
61 #define CFG_CR2700 0x30
64 #define R1MS_MASK (0x01 << (R1MS_SHIFT))
65 #define R2MS_MASK (0x01 << (R2MS_SHIFT))
68 #define R1DF_MASK (0x01 << (R1DF_SHIFT))
69 #define R2DF_MASK (0x01 << (R2DF_SHIFT))
70 #define R1FE_MASK 0x01
71 #define R2FE_MASK 0x05
77 #define MANUFACTURER_ID 0x01
78 #define DEFAULT_REVISION 0xA4
80 static const u8 lm95241_reg_address[] = {
81 LM95241_REG_R_LOCAL_TEMPH,
82 LM95241_REG_R_LOCAL_TEMPL,
83 LM95241_REG_R_REMOTE1_TEMPH,
84 LM95241_REG_R_REMOTE1_TEMPL,
85 LM95241_REG_R_REMOTE2_TEMPH,
86 LM95241_REG_R_REMOTE2_TEMPL
89 /* Client data (each client gets its own) */
91 struct device *hwmon_dev;
92 struct mutex update_lock;
93 unsigned long last_updated, interval; /* in jiffies */
94 char valid; /* zero until following fields are valid */
95 /* registers values */
96 u8 temp[ARRAY_SIZE(lm95241_reg_address)];
97 u8 config, model, trutherm;
101 static int temp_from_reg_signed(u8 val_h, u8 val_l)
103 s16 val_hl = (val_h << 8) | val_l;
104 return val_hl * 1000 / 256;
107 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
109 u16 val_hl = (val_h << 8) | val_l;
110 return val_hl * 1000 / 256;
113 static struct lm95241_data *lm95241_update_device(struct device *dev)
115 struct i2c_client *client = to_i2c_client(dev);
116 struct lm95241_data *data = i2c_get_clientdata(client);
118 mutex_lock(&data->update_lock);
120 if (time_after(jiffies, data->last_updated + data->interval) ||
124 dev_dbg(&client->dev, "Updating lm95241 data.\n");
125 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
127 = i2c_smbus_read_byte_data(client,
128 lm95241_reg_address[i]);
129 data->last_updated = jiffies;
133 mutex_unlock(&data->update_lock);
139 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
142 struct lm95241_data *data = lm95241_update_device(dev);
143 int index = to_sensor_dev_attr(attr)->index;
145 return snprintf(buf, PAGE_SIZE - 1, "%d\n",
146 index == 0 || (data->config & (1 << (index / 2))) ?
147 temp_from_reg_signed(data->temp[index], data->temp[index + 1]) :
148 temp_from_reg_unsigned(data->temp[index],
149 data->temp[index + 1]));
152 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
155 struct i2c_client *client = to_i2c_client(dev);
156 struct lm95241_data *data = i2c_get_clientdata(client);
158 return snprintf(buf, PAGE_SIZE - 1,
159 data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
162 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
163 const char *buf, size_t count)
165 struct i2c_client *client = to_i2c_client(dev);
166 struct lm95241_data *data = i2c_get_clientdata(client);
169 u8 mask = to_sensor_dev_attr(attr)->index;
171 if (strict_strtoul(buf, 10, &val) < 0)
173 if (val != 1 && val != 2)
176 shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
178 mutex_lock(&data->update_lock);
180 data->trutherm &= ~(TT_MASK << shift);
183 data->trutherm |= (TT_ON << shift);
185 data->model &= ~mask;
186 data->trutherm |= (TT_OFF << shift);
190 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
192 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
195 mutex_unlock(&data->update_lock);
200 static ssize_t show_min(struct device *dev, struct device_attribute *attr,
203 struct i2c_client *client = to_i2c_client(dev);
204 struct lm95241_data *data = i2c_get_clientdata(client);
206 return snprintf(buf, PAGE_SIZE - 1,
207 data->config & to_sensor_dev_attr(attr)->index ?
208 "-127000\n" : "0\n");
211 static ssize_t set_min(struct device *dev, struct device_attribute *attr,
212 const char *buf, size_t count)
214 struct i2c_client *client = to_i2c_client(dev);
215 struct lm95241_data *data = i2c_get_clientdata(client);
218 if (strict_strtol(buf, 10, &val) < 0)
223 mutex_lock(&data->update_lock);
226 data->config |= to_sensor_dev_attr(attr)->index;
228 data->config &= ~to_sensor_dev_attr(attr)->index;
231 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
233 mutex_unlock(&data->update_lock);
238 static ssize_t show_max(struct device *dev, struct device_attribute *attr,
241 struct i2c_client *client = to_i2c_client(dev);
242 struct lm95241_data *data = i2c_get_clientdata(client);
244 return snprintf(buf, PAGE_SIZE - 1,
245 data->config & to_sensor_dev_attr(attr)->index ?
246 "127000\n" : "255000\n");
249 static ssize_t set_max(struct device *dev, struct device_attribute *attr,
250 const char *buf, size_t count)
252 struct i2c_client *client = to_i2c_client(dev);
253 struct lm95241_data *data = i2c_get_clientdata(client);
256 if (strict_strtol(buf, 10, &val) < 0)
261 mutex_lock(&data->update_lock);
264 data->config |= to_sensor_dev_attr(attr)->index;
266 data->config &= ~to_sensor_dev_attr(attr)->index;
269 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
271 mutex_unlock(&data->update_lock);
276 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
279 struct lm95241_data *data = lm95241_update_device(dev);
281 return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
285 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
286 const char *buf, size_t count)
288 struct i2c_client *client = to_i2c_client(dev);
289 struct lm95241_data *data = i2c_get_clientdata(client);
292 if (strict_strtoul(buf, 10, &val) < 0)
295 data->interval = val * HZ / 1000;
300 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
301 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
302 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
303 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
305 static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
307 static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
309 static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
311 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
313 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
315 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
318 static struct attribute *lm95241_attributes[] = {
319 &sensor_dev_attr_temp1_input.dev_attr.attr,
320 &sensor_dev_attr_temp2_input.dev_attr.attr,
321 &sensor_dev_attr_temp3_input.dev_attr.attr,
322 &sensor_dev_attr_temp2_type.dev_attr.attr,
323 &sensor_dev_attr_temp3_type.dev_attr.attr,
324 &sensor_dev_attr_temp2_min.dev_attr.attr,
325 &sensor_dev_attr_temp3_min.dev_attr.attr,
326 &sensor_dev_attr_temp2_max.dev_attr.attr,
327 &sensor_dev_attr_temp3_max.dev_attr.attr,
328 &dev_attr_update_interval.attr,
332 static const struct attribute_group lm95241_group = {
333 .attrs = lm95241_attributes,
336 /* Return 0 if detection is successful, -ENODEV otherwise */
337 static int lm95241_detect(struct i2c_client *new_client,
338 struct i2c_board_info *info)
340 struct i2c_adapter *adapter = new_client->adapter;
341 int address = new_client->addr;
344 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
347 if ((i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID)
349 && (i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID)
350 == DEFAULT_REVISION)) {
353 dev_dbg(&adapter->dev, "LM95241 detection failed at 0x%02x\n",
358 /* Fill the i2c board info */
359 strlcpy(info->type, name, I2C_NAME_SIZE);
363 static void lm95241_init_client(struct i2c_client *client)
365 struct lm95241_data *data = i2c_get_clientdata(client);
367 data->interval = HZ; /* 1 sec default */
369 data->config = CFG_CR0076;
371 data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
373 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
374 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
375 R1FE_MASK | R2FE_MASK);
376 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
378 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
382 static int lm95241_probe(struct i2c_client *new_client,
383 const struct i2c_device_id *id)
385 struct lm95241_data *data;
388 data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
394 i2c_set_clientdata(new_client, data);
395 mutex_init(&data->update_lock);
397 /* Initialize the LM95241 chip */
398 lm95241_init_client(new_client);
400 /* Register sysfs hooks */
401 err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
405 data->hwmon_dev = hwmon_device_register(&new_client->dev);
406 if (IS_ERR(data->hwmon_dev)) {
407 err = PTR_ERR(data->hwmon_dev);
408 goto exit_remove_files;
414 sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
421 static int lm95241_remove(struct i2c_client *client)
423 struct lm95241_data *data = i2c_get_clientdata(client);
425 hwmon_device_unregister(data->hwmon_dev);
426 sysfs_remove_group(&client->dev.kobj, &lm95241_group);
432 /* Driver data (common to all clients) */
433 static const struct i2c_device_id lm95241_id[] = {
437 MODULE_DEVICE_TABLE(i2c, lm95241_id);
439 static struct i2c_driver lm95241_driver = {
440 .class = I2C_CLASS_HWMON,
444 .probe = lm95241_probe,
445 .remove = lm95241_remove,
446 .id_table = lm95241_id,
447 .detect = lm95241_detect,
448 .address_list = normal_i2c,
451 static int __init sensors_lm95241_init(void)
453 return i2c_add_driver(&lm95241_driver);
456 static void __exit sensors_lm95241_exit(void)
458 i2c_del_driver(&lm95241_driver);
461 MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
462 MODULE_DESCRIPTION("LM95241 sensor driver");
463 MODULE_LICENSE("GPL");
465 module_init(sensors_lm95241_init);
466 module_exit(sensors_lm95241_exit);