2 * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com>
4 * The LM95245 is a sensor chip made by National Semiconductors.
5 * It reports up to two temperatures (its own plus an external one).
6 * Complete datasheet can be obtained from National's website at:
7 * http://www.national.com/ds.cgi/LM/LM95245.pdf
9 * This driver is based on lm95241.c
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; either version 2 of the License, or
14 * (at your option) any later version.
16 * This program is distributed in the hope that it will be useful,
17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 * GNU General Public License for more details.
21 * You should have received a copy of the GNU General Public License
22 * along with this program; if not, write to the Free Software
23 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26 #include <linux/module.h>
27 #include <linux/init.h>
28 #include <linux/slab.h>
29 #include <linux/jiffies.h>
30 #include <linux/i2c.h>
31 #include <linux/hwmon.h>
32 #include <linux/hwmon-sysfs.h>
33 #include <linux/err.h>
34 #include <linux/mutex.h>
35 #include <linux/sysfs.h>
37 #define DEVNAME "lm95245"
39 static const unsigned short normal_i2c[] = {
40 0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END };
42 /* LM95245 registers */
43 /* general registers */
44 #define LM95245_REG_RW_CONFIG1 0x03
45 #define LM95245_REG_RW_CONVERS_RATE 0x04
46 #define LM95245_REG_W_ONE_SHOT 0x0F
48 /* diode configuration */
49 #define LM95245_REG_RW_CONFIG2 0xBF
50 #define LM95245_REG_RW_REMOTE_OFFH 0x11
51 #define LM95245_REG_RW_REMOTE_OFFL 0x12
53 /* status registers */
54 #define LM95245_REG_R_STATUS1 0x02
55 #define LM95245_REG_R_STATUS2 0x33
58 #define LM95245_REG_RW_REMOTE_OS_LIMIT 0x07
59 #define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT 0x20
60 #define LM95245_REG_RW_REMOTE_TCRIT_LIMIT 0x19
61 #define LM95245_REG_RW_COMMON_HYSTERESIS 0x21
63 /* temperature signed */
64 #define LM95245_REG_R_LOCAL_TEMPH_S 0x00
65 #define LM95245_REG_R_LOCAL_TEMPL_S 0x30
66 #define LM95245_REG_R_REMOTE_TEMPH_S 0x01
67 #define LM95245_REG_R_REMOTE_TEMPL_S 0x10
68 /* temperature unsigned */
69 #define LM95245_REG_R_REMOTE_TEMPH_U 0x31
70 #define LM95245_REG_R_REMOTE_TEMPL_U 0x32
73 #define LM95245_REG_R_MAN_ID 0xFE
74 #define LM95245_REG_R_CHIP_ID 0xFF
76 /* LM95245 specific bitfields */
78 #define CFG_REMOTE_TCRIT_MASK 0x10
79 #define CFG_REMOTE_OS_MASK 0x08
80 #define CFG_LOCAL_TCRIT_MASK 0x04
81 #define CFG_LOCAL_OS_MASK 0x02
83 #define CFG2_OS_A0 0x40
84 #define CFG2_DIODE_FAULT_OS 0x20
85 #define CFG2_DIODE_FAULT_TCRIT 0x10
86 #define CFG2_REMOTE_TT 0x08
87 #define CFG2_REMOTE_FILTER_DIS 0x00
88 #define CFG2_REMOTE_FILTER_EN 0x06
90 /* conversation rate in ms */
91 #define RATE_CR0063 0x00
92 #define RATE_CR0364 0x01
93 #define RATE_CR1000 0x02
94 #define RATE_CR2500 0x03
96 #define STATUS1_DIODE_FAULT 0x04
97 #define STATUS1_RTCRIT 0x02
98 #define STATUS1_LOC 0x01
100 #define MANUFACTURER_ID 0x01
101 #define DEFAULT_REVISION 0xB3
103 static const u8 lm95245_reg_address[] = {
104 LM95245_REG_R_LOCAL_TEMPH_S,
105 LM95245_REG_R_LOCAL_TEMPL_S,
106 LM95245_REG_R_REMOTE_TEMPH_S,
107 LM95245_REG_R_REMOTE_TEMPL_S,
108 LM95245_REG_R_REMOTE_TEMPH_U,
109 LM95245_REG_R_REMOTE_TEMPL_U,
110 LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
111 LM95245_REG_RW_REMOTE_TCRIT_LIMIT,
112 LM95245_REG_RW_COMMON_HYSTERESIS,
113 LM95245_REG_R_STATUS1,
116 /* Client data (each client gets its own) */
117 struct lm95245_data {
118 struct device *hwmon_dev;
119 struct mutex update_lock;
120 unsigned long last_updated; /* in jiffies */
121 unsigned long interval; /* in msecs */
122 bool valid; /* zero until following fields are valid */
123 /* registers values */
124 u8 regs[ARRAY_SIZE(lm95245_reg_address)];
129 static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
131 return val_h * 1000 + val_l * 1000 / 256;
134 static int temp_from_reg_signed(u8 val_h, u8 val_l)
137 return (val_h - 0x100) * 1000;
138 return temp_from_reg_unsigned(val_h, val_l);
141 static struct lm95245_data *lm95245_update_device(struct device *dev)
143 struct i2c_client *client = to_i2c_client(dev);
144 struct lm95245_data *data = i2c_get_clientdata(client);
146 mutex_lock(&data->update_lock);
148 if (time_after(jiffies, data->last_updated
149 + msecs_to_jiffies(data->interval)) || !data->valid) {
152 dev_dbg(&client->dev, "Updating lm95245 data.\n");
153 for (i = 0; i < ARRAY_SIZE(lm95245_reg_address); i++)
155 = i2c_smbus_read_byte_data(client,
156 lm95245_reg_address[i]);
157 data->last_updated = jiffies;
161 mutex_unlock(&data->update_lock);
166 static unsigned long lm95245_read_conversion_rate(struct i2c_client *client)
169 unsigned long interval;
171 rate = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONVERS_RATE);
192 static unsigned long lm95245_set_conversion_rate(struct i2c_client *client,
193 unsigned long interval)
197 if (interval <= 63) {
200 } else if (interval <= 364) {
203 } else if (interval <= 1000) {
211 i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONVERS_RATE, rate);
217 static ssize_t show_input(struct device *dev, struct device_attribute *attr,
220 struct lm95245_data *data = lm95245_update_device(dev);
222 int index = to_sensor_dev_attr(attr)->index;
225 * Index 0 (Local temp) is always signed
226 * Index 2 (Remote temp) has both signed and unsigned data
227 * use signed calculation for remote if signed bit is set
229 if (index == 0 || data->regs[index] & 0x80)
230 temp = temp_from_reg_signed(data->regs[index],
231 data->regs[index + 1]);
233 temp = temp_from_reg_unsigned(data->regs[index + 2],
234 data->regs[index + 3]);
236 return snprintf(buf, PAGE_SIZE - 1, "%d\n", temp);
239 static ssize_t show_limit(struct device *dev, struct device_attribute *attr,
242 struct lm95245_data *data = lm95245_update_device(dev);
243 int index = to_sensor_dev_attr(attr)->index;
245 return snprintf(buf, PAGE_SIZE - 1, "%d\n",
246 data->regs[index] * 1000);
249 static ssize_t set_limit(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 lm95245_data *data = i2c_get_clientdata(client);
254 int index = to_sensor_dev_attr(attr)->index;
257 if (kstrtoul(buf, 10, &val) < 0)
262 val = SENSORS_LIMIT(val, 0, (index == 6 ? 127 : 255));
264 mutex_lock(&data->update_lock);
268 i2c_smbus_write_byte_data(client, lm95245_reg_address[index], val);
270 mutex_unlock(&data->update_lock);
275 static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr,
276 const char *buf, size_t count)
278 struct i2c_client *client = to_i2c_client(dev);
279 struct lm95245_data *data = i2c_get_clientdata(client);
282 if (kstrtoul(buf, 10, &val) < 0)
287 val = SENSORS_LIMIT(val, 0, 31);
289 mutex_lock(&data->update_lock);
293 /* shared crit hysteresis */
294 i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS,
297 mutex_unlock(&data->update_lock);
302 static ssize_t show_type(struct device *dev, struct device_attribute *attr,
305 struct i2c_client *client = to_i2c_client(dev);
306 struct lm95245_data *data = i2c_get_clientdata(client);
308 return snprintf(buf, PAGE_SIZE - 1,
309 data->config2 & CFG2_REMOTE_TT ? "1\n" : "2\n");
312 static ssize_t set_type(struct device *dev, struct device_attribute *attr,
313 const char *buf, size_t count)
315 struct i2c_client *client = to_i2c_client(dev);
316 struct lm95245_data *data = i2c_get_clientdata(client);
319 if (kstrtoul(buf, 10, &val) < 0)
321 if (val != 1 && val != 2)
324 mutex_lock(&data->update_lock);
327 data->config2 |= CFG2_REMOTE_TT;
329 data->config2 &= ~CFG2_REMOTE_TT;
333 i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2,
336 mutex_unlock(&data->update_lock);
341 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
344 struct lm95245_data *data = lm95245_update_device(dev);
345 int index = to_sensor_dev_attr(attr)->index;
347 return snprintf(buf, PAGE_SIZE - 1, "%d\n",
348 !!(data->regs[9] & index));
351 static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
354 struct lm95245_data *data = lm95245_update_device(dev);
356 return snprintf(buf, PAGE_SIZE - 1, "%lu\n", data->interval);
359 static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
360 const char *buf, size_t count)
362 struct i2c_client *client = to_i2c_client(dev);
363 struct lm95245_data *data = i2c_get_clientdata(client);
366 if (kstrtoul(buf, 10, &val) < 0)
369 mutex_lock(&data->update_lock);
371 data->interval = lm95245_set_conversion_rate(client, val);
373 mutex_unlock(&data->update_lock);
378 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
379 static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit,
381 static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_limit,
383 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
386 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
387 static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit,
389 static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IWUSR | S_IRUGO, show_limit,
391 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
393 static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type,
395 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL,
396 STATUS1_DIODE_FAULT);
398 static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
401 static struct attribute *lm95245_attributes[] = {
402 &sensor_dev_attr_temp1_input.dev_attr.attr,
403 &sensor_dev_attr_temp1_crit.dev_attr.attr,
404 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
405 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
406 &sensor_dev_attr_temp2_input.dev_attr.attr,
407 &sensor_dev_attr_temp2_crit.dev_attr.attr,
408 &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
409 &sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
410 &sensor_dev_attr_temp2_type.dev_attr.attr,
411 &sensor_dev_attr_temp2_fault.dev_attr.attr,
412 &dev_attr_update_interval.attr,
416 static const struct attribute_group lm95245_group = {
417 .attrs = lm95245_attributes,
420 /* Return 0 if detection is successful, -ENODEV otherwise */
421 static int lm95245_detect(struct i2c_client *new_client,
422 struct i2c_board_info *info)
424 struct i2c_adapter *adapter = new_client->adapter;
426 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
429 if (i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID)
431 || i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID)
435 strlcpy(info->type, DEVNAME, I2C_NAME_SIZE);
439 static void lm95245_init_client(struct i2c_client *client)
441 struct lm95245_data *data = i2c_get_clientdata(client);
444 data->interval = lm95245_read_conversion_rate(client);
446 data->config1 = i2c_smbus_read_byte_data(client,
447 LM95245_REG_RW_CONFIG1);
448 data->config2 = i2c_smbus_read_byte_data(client,
449 LM95245_REG_RW_CONFIG2);
451 if (data->config1 & CFG_STOP) {
452 /* Clear the standby bit */
453 data->config1 &= ~CFG_STOP;
454 i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1,
459 static int lm95245_probe(struct i2c_client *new_client,
460 const struct i2c_device_id *id)
462 struct lm95245_data *data;
465 data = devm_kzalloc(&new_client->dev, sizeof(struct lm95245_data),
470 i2c_set_clientdata(new_client, data);
471 mutex_init(&data->update_lock);
473 /* Initialize the LM95245 chip */
474 lm95245_init_client(new_client);
476 /* Register sysfs hooks */
477 err = sysfs_create_group(&new_client->dev.kobj, &lm95245_group);
481 data->hwmon_dev = hwmon_device_register(&new_client->dev);
482 if (IS_ERR(data->hwmon_dev)) {
483 err = PTR_ERR(data->hwmon_dev);
484 goto exit_remove_files;
490 sysfs_remove_group(&new_client->dev.kobj, &lm95245_group);
494 static int lm95245_remove(struct i2c_client *client)
496 struct lm95245_data *data = i2c_get_clientdata(client);
498 hwmon_device_unregister(data->hwmon_dev);
499 sysfs_remove_group(&client->dev.kobj, &lm95245_group);
504 /* Driver data (common to all clients) */
505 static const struct i2c_device_id lm95245_id[] = {
509 MODULE_DEVICE_TABLE(i2c, lm95245_id);
511 static struct i2c_driver lm95245_driver = {
512 .class = I2C_CLASS_HWMON,
516 .probe = lm95245_probe,
517 .remove = lm95245_remove,
518 .id_table = lm95245_id,
519 .detect = lm95245_detect,
520 .address_list = normal_i2c,
523 module_i2c_driver(lm95245_driver);
525 MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
526 MODULE_DESCRIPTION("LM95245 sensor driver");
527 MODULE_LICENSE("GPL");