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1/*
2 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
3 *
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
8 *
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.
13 *
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.
18 *
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.
22 */
23
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>
34
35#define DEVNAME "lm95241"
36
37static const unsigned short normal_i2c[] = {
38 0x19, 0x2a, 0x2b, I2C_CLIENT_END };
39
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
55
56/* LM95241 specific bitfields */
57#define CFG_STOP 0x40
58#define CFG_CR0076 0x00
59#define CFG_CR0182 0x10
60#define CFG_CR1000 0x20
61#define CFG_CR2700 0x30
62#define R1MS_SHIFT 0
63#define R2MS_SHIFT 2
64#define R1MS_MASK (0x01 << (R1MS_SHIFT))
65#define R2MS_MASK (0x01 << (R2MS_SHIFT))
66#define R1DF_SHIFT 1
67#define R2DF_SHIFT 2
68#define R1DF_MASK (0x01 << (R1DF_SHIFT))
69#define R2DF_MASK (0x01 << (R2DF_SHIFT))
70#define R1FE_MASK 0x01
71#define R2FE_MASK 0x05
72#define TT1_SHIFT 0
73#define TT2_SHIFT 4
74#define TT_OFF 0
75#define TT_ON 1
76#define TT_MASK 7
77#define NATSEMI_MAN_ID 0x01
78#define LM95231_CHIP_ID 0xA1
79#define LM95241_CHIP_ID 0xA4
80
81static const u8 lm95241_reg_address[] = {
82 LM95241_REG_R_LOCAL_TEMPH,
83 LM95241_REG_R_LOCAL_TEMPL,
84 LM95241_REG_R_REMOTE1_TEMPH,
85 LM95241_REG_R_REMOTE1_TEMPL,
86 LM95241_REG_R_REMOTE2_TEMPH,
87 LM95241_REG_R_REMOTE2_TEMPL
88};
89
90/* Client data (each client gets its own) */
91struct lm95241_data {
92 struct device *hwmon_dev;
93 struct mutex update_lock;
94 unsigned long last_updated, interval; /* in jiffies */
95 char valid; /* zero until following fields are valid */
96 /* registers values */
97 u8 temp[ARRAY_SIZE(lm95241_reg_address)];
98 u8 config, model, trutherm;
99};
100
101/* Conversions */
102static int temp_from_reg_signed(u8 val_h, u8 val_l)
103{
104 s16 val_hl = (val_h << 8) | val_l;
105 return val_hl * 1000 / 256;
106}
107
108static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
109{
110 u16 val_hl = (val_h << 8) | val_l;
111 return val_hl * 1000 / 256;
112}
113
114static struct lm95241_data *lm95241_update_device(struct device *dev)
115{
116 struct i2c_client *client = to_i2c_client(dev);
117 struct lm95241_data *data = i2c_get_clientdata(client);
118
119 mutex_lock(&data->update_lock);
120
121 if (time_after(jiffies, data->last_updated + data->interval) ||
122 !data->valid) {
123 int i;
124
125 dev_dbg(&client->dev, "Updating lm95241 data.\n");
126 for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
127 data->temp[i]
128 = i2c_smbus_read_byte_data(client,
129 lm95241_reg_address[i]);
130 data->last_updated = jiffies;
131 data->valid = 1;
132 }
133
134 mutex_unlock(&data->update_lock);
135
136 return data;
137}
138
139/* Sysfs stuff */
140static ssize_t show_input(struct device *dev, struct device_attribute *attr,
141 char *buf)
142{
143 struct lm95241_data *data = lm95241_update_device(dev);
144 int index = to_sensor_dev_attr(attr)->index;
145
146 return snprintf(buf, PAGE_SIZE - 1, "%d\n",
147 index == 0 || (data->config & (1 << (index / 2))) ?
148 temp_from_reg_signed(data->temp[index], data->temp[index + 1]) :
149 temp_from_reg_unsigned(data->temp[index],
150 data->temp[index + 1]));
151}
152
153static ssize_t show_type(struct device *dev, struct device_attribute *attr,
154 char *buf)
155{
156 struct i2c_client *client = to_i2c_client(dev);
157 struct lm95241_data *data = i2c_get_clientdata(client);
158
159 return snprintf(buf, PAGE_SIZE - 1,
160 data->model & to_sensor_dev_attr(attr)->index ? "1\n" : "2\n");
161}
162
163static ssize_t set_type(struct device *dev, struct device_attribute *attr,
164 const char *buf, size_t count)
165{
166 struct i2c_client *client = to_i2c_client(dev);
167 struct lm95241_data *data = i2c_get_clientdata(client);
168 unsigned long val;
169 int shift;
170 u8 mask = to_sensor_dev_attr(attr)->index;
171
172 if (kstrtoul(buf, 10, &val) < 0)
173 return -EINVAL;
174 if (val != 1 && val != 2)
175 return -EINVAL;
176
177 shift = mask == R1MS_MASK ? TT1_SHIFT : TT2_SHIFT;
178
179 mutex_lock(&data->update_lock);
180
181 data->trutherm &= ~(TT_MASK << shift);
182 if (val == 1) {
183 data->model |= mask;
184 data->trutherm |= (TT_ON << shift);
185 } else {
186 data->model &= ~mask;
187 data->trutherm |= (TT_OFF << shift);
188 }
189 data->valid = 0;
190
191 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
192 data->model);
193 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
194 data->trutherm);
195
196 mutex_unlock(&data->update_lock);
197
198 return count;
199}
200
201static ssize_t show_min(struct device *dev, struct device_attribute *attr,
202 char *buf)
203{
204 struct i2c_client *client = to_i2c_client(dev);
205 struct lm95241_data *data = i2c_get_clientdata(client);
206
207 return snprintf(buf, PAGE_SIZE - 1,
208 data->config & to_sensor_dev_attr(attr)->index ?
209 "-127000\n" : "0\n");
210}
211
212static ssize_t set_min(struct device *dev, struct device_attribute *attr,
213 const char *buf, size_t count)
214{
215 struct i2c_client *client = to_i2c_client(dev);
216 struct lm95241_data *data = i2c_get_clientdata(client);
217 long val;
218
219 if (kstrtol(buf, 10, &val) < 0)
220 return -EINVAL;
221 if (val < -128000)
222 return -EINVAL;
223
224 mutex_lock(&data->update_lock);
225
226 if (val < 0)
227 data->config |= to_sensor_dev_attr(attr)->index;
228 else
229 data->config &= ~to_sensor_dev_attr(attr)->index;
230 data->valid = 0;
231
232 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
233
234 mutex_unlock(&data->update_lock);
235
236 return count;
237}
238
239static ssize_t show_max(struct device *dev, struct device_attribute *attr,
240 char *buf)
241{
242 struct i2c_client *client = to_i2c_client(dev);
243 struct lm95241_data *data = i2c_get_clientdata(client);
244
245 return snprintf(buf, PAGE_SIZE - 1,
246 data->config & to_sensor_dev_attr(attr)->index ?
247 "127000\n" : "255000\n");
248}
249
250static ssize_t set_max(struct device *dev, struct device_attribute *attr,
251 const char *buf, size_t count)
252{
253 struct i2c_client *client = to_i2c_client(dev);
254 struct lm95241_data *data = i2c_get_clientdata(client);
255 long val;
256
257 if (kstrtol(buf, 10, &val) < 0)
258 return -EINVAL;
259 if (val >= 256000)
260 return -EINVAL;
261
262 mutex_lock(&data->update_lock);
263
264 if (val <= 127000)
265 data->config |= to_sensor_dev_attr(attr)->index;
266 else
267 data->config &= ~to_sensor_dev_attr(attr)->index;
268 data->valid = 0;
269
270 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
271
272 mutex_unlock(&data->update_lock);
273
274 return count;
275}
276
277static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
278 char *buf)
279{
280 struct lm95241_data *data = lm95241_update_device(dev);
281
282 return snprintf(buf, PAGE_SIZE - 1, "%lu\n", 1000 * data->interval
283 / HZ);
284}
285
286static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
287 const char *buf, size_t count)
288{
289 struct i2c_client *client = to_i2c_client(dev);
290 struct lm95241_data *data = i2c_get_clientdata(client);
291 unsigned long val;
292
293 if (kstrtoul(buf, 10, &val) < 0)
294 return -EINVAL;
295
296 data->interval = val * HZ / 1000;
297
298 return count;
299}
300
301static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
302static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
303static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_input, NULL, 4);
304static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type, set_type,
305 R1MS_MASK);
306static SENSOR_DEVICE_ATTR(temp3_type, S_IWUSR | S_IRUGO, show_type, set_type,
307 R2MS_MASK);
308static SENSOR_DEVICE_ATTR(temp2_min, S_IWUSR | S_IRUGO, show_min, set_min,
309 R1DF_MASK);
310static SENSOR_DEVICE_ATTR(temp3_min, S_IWUSR | S_IRUGO, show_min, set_min,
311 R2DF_MASK);
312static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_max, set_max,
313 R1DF_MASK);
314static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_max, set_max,
315 R2DF_MASK);
316static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
317 set_interval);
318
319static struct attribute *lm95241_attributes[] = {
320 &sensor_dev_attr_temp1_input.dev_attr.attr,
321 &sensor_dev_attr_temp2_input.dev_attr.attr,
322 &sensor_dev_attr_temp3_input.dev_attr.attr,
323 &sensor_dev_attr_temp2_type.dev_attr.attr,
324 &sensor_dev_attr_temp3_type.dev_attr.attr,
325 &sensor_dev_attr_temp2_min.dev_attr.attr,
326 &sensor_dev_attr_temp3_min.dev_attr.attr,
327 &sensor_dev_attr_temp2_max.dev_attr.attr,
328 &sensor_dev_attr_temp3_max.dev_attr.attr,
329 &dev_attr_update_interval.attr,
330 NULL
331};
332
333static const struct attribute_group lm95241_group = {
334 .attrs = lm95241_attributes,
335};
336
337/* Return 0 if detection is successful, -ENODEV otherwise */
338static int lm95241_detect(struct i2c_client *new_client,
339 struct i2c_board_info *info)
340{
341 struct i2c_adapter *adapter = new_client->adapter;
342 const char *name;
343 int mfg_id, chip_id;
344
345 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
346 return -ENODEV;
347
348 mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
349 if (mfg_id != NATSEMI_MAN_ID)
350 return -ENODEV;
351
352 chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
353 switch (chip_id) {
354 case LM95231_CHIP_ID:
355 name = "lm95231";
356 break;
357 case LM95241_CHIP_ID:
358 name = "lm95241";
359 break;
360 default:
361 return -ENODEV;
362 }
363
364 /* Fill the i2c board info */
365 strlcpy(info->type, name, I2C_NAME_SIZE);
366 return 0;
367}
368
369static void lm95241_init_client(struct i2c_client *client)
370{
371 struct lm95241_data *data = i2c_get_clientdata(client);
372
373 data->interval = HZ; /* 1 sec default */
374 data->valid = 0;
375 data->config = CFG_CR0076;
376 data->model = 0;
377 data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
378
379 i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
380 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
381 R1FE_MASK | R2FE_MASK);
382 i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
383 data->trutherm);
384 i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
385 data->model);
386}
387
388static int lm95241_probe(struct i2c_client *new_client,
389 const struct i2c_device_id *id)
390{
391 struct lm95241_data *data;
392 int err;
393
394 data = kzalloc(sizeof(struct lm95241_data), GFP_KERNEL);
395 if (!data) {
396 err = -ENOMEM;
397 goto exit;
398 }
399
400 i2c_set_clientdata(new_client, data);
401 mutex_init(&data->update_lock);
402
403 /* Initialize the LM95241 chip */
404 lm95241_init_client(new_client);
405
406 /* Register sysfs hooks */
407 err = sysfs_create_group(&new_client->dev.kobj, &lm95241_group);
408 if (err)
409 goto exit_free;
410
411 data->hwmon_dev = hwmon_device_register(&new_client->dev);
412 if (IS_ERR(data->hwmon_dev)) {
413 err = PTR_ERR(data->hwmon_dev);
414 goto exit_remove_files;
415 }
416
417 return 0;
418
419exit_remove_files:
420 sysfs_remove_group(&new_client->dev.kobj, &lm95241_group);
421exit_free:
422 kfree(data);
423exit:
424 return err;
425}
426
427static int lm95241_remove(struct i2c_client *client)
428{
429 struct lm95241_data *data = i2c_get_clientdata(client);
430
431 hwmon_device_unregister(data->hwmon_dev);
432 sysfs_remove_group(&client->dev.kobj, &lm95241_group);
433
434 kfree(data);
435 return 0;
436}
437
438/* Driver data (common to all clients) */
439static const struct i2c_device_id lm95241_id[] = {
440 { "lm95231", 0 },
441 { "lm95241", 0 },
442 { }
443};
444MODULE_DEVICE_TABLE(i2c, lm95241_id);
445
446static struct i2c_driver lm95241_driver = {
447 .class = I2C_CLASS_HWMON,
448 .driver = {
449 .name = DEVNAME,
450 },
451 .probe = lm95241_probe,
452 .remove = lm95241_remove,
453 .id_table = lm95241_id,
454 .detect = lm95241_detect,
455 .address_list = normal_i2c,
456};
457
458module_i2c_driver(lm95241_driver);
459
460MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
461MODULE_DESCRIPTION("LM95241 sensor driver");
462MODULE_LICENSE("GPL");