blob: dd969f1e84154e6d754b63cfd8f013d09b3dc87e [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 lm77.c - Part of lm_sensors, Linux kernel modules for hardware
3 monitoring
4
5 Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
6
7 Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
8 is a temperature sensor and thermal window comparator with 0.5 deg
9 resolution made by National Semiconductor. Complete datasheet can be
10 obtained at their site:
11 http://www.national.com/pf/LM/LM77.html
12
13 This program is free software; you can redistribute it and/or modify
14 it under the terms of the GNU General Public License as published by
15 the Free Software Foundation; either version 2 of the License, or
16 (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26*/
27
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/module.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/jiffies.h>
32#include <linux/i2c.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040033#include <linux/hwmon.h>
34#include <linux/err.h>
Ingo Molnar9a61bf62006-01-18 23:19:26 +010035#include <linux/mutex.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37/* Addresses to scan */
38static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
40/* Insmod parameters */
Jean Delvaref4b50262005-07-31 21:49:03 +020041I2C_CLIENT_INSMOD_1(lm77);
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
43/* The LM77 registers */
44#define LM77_REG_TEMP 0x00
45#define LM77_REG_CONF 0x01
46#define LM77_REG_TEMP_HYST 0x02
47#define LM77_REG_TEMP_CRIT 0x03
48#define LM77_REG_TEMP_MIN 0x04
49#define LM77_REG_TEMP_MAX 0x05
50
51/* Each client has this additional data */
52struct lm77_data {
53 struct i2c_client client;
Mark M. Hoffman943b0832005-07-15 21:39:18 -040054 struct class_device *class_dev;
Ingo Molnar9a61bf62006-01-18 23:19:26 +010055 struct mutex update_lock;
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 char valid;
57 unsigned long last_updated; /* In jiffies */
58 int temp_input; /* Temperatures */
59 int temp_crit;
60 int temp_min;
61 int temp_max;
62 int temp_hyst;
63 u8 alarms;
64};
65
66static int lm77_attach_adapter(struct i2c_adapter *adapter);
67static int lm77_detect(struct i2c_adapter *adapter, int address, int kind);
68static void lm77_init_client(struct i2c_client *client);
69static int lm77_detach_client(struct i2c_client *client);
70static u16 lm77_read_value(struct i2c_client *client, u8 reg);
71static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
72
73static struct lm77_data *lm77_update_device(struct device *dev);
74
75
76/* This is the driver that will be inserted */
77static struct i2c_driver lm77_driver = {
Laurent Riffardcdaf7932005-11-26 20:37:41 +010078 .driver = {
Laurent Riffardcdaf7932005-11-26 20:37:41 +010079 .name = "lm77",
80 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 .attach_adapter = lm77_attach_adapter,
82 .detach_client = lm77_detach_client,
83};
84
85/* straight from the datasheet */
86#define LM77_TEMP_MIN (-55000)
87#define LM77_TEMP_MAX 125000
88
89/* In the temperature registers, the low 3 bits are not part of the
90 temperature values; they are the status bits. */
Jean Delvare413b6452006-01-09 22:43:08 +010091static inline s16 LM77_TEMP_TO_REG(int temp)
Linus Torvalds1da177e2005-04-16 15:20:36 -070092{
93 int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
Jean Delvare413b6452006-01-09 22:43:08 +010094 return (ntemp / 500) * 8;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095}
96
Jean Delvare413b6452006-01-09 22:43:08 +010097static inline int LM77_TEMP_FROM_REG(s16 reg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070098{
Jean Delvare413b6452006-01-09 22:43:08 +010099 return (reg / 8) * 500;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100}
101
102/* sysfs stuff */
103
104/* read routines for temperature limits */
105#define show(value) \
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400106static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107{ \
108 struct lm77_data *data = lm77_update_device(dev); \
109 return sprintf(buf, "%d\n", data->value); \
110}
111
112show(temp_input);
113show(temp_crit);
114show(temp_min);
115show(temp_max);
116show(alarms);
117
118/* read routines for hysteresis values */
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400119static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120{
121 struct lm77_data *data = lm77_update_device(dev);
122 return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
123}
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400124static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125{
126 struct lm77_data *data = lm77_update_device(dev);
127 return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
128}
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400129static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130{
131 struct lm77_data *data = lm77_update_device(dev);
132 return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
133}
134
135/* write routines */
136#define set(value, reg) \
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400137static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138{ \
139 struct i2c_client *client = to_i2c_client(dev); \
140 struct lm77_data *data = i2c_get_clientdata(client); \
141 long val = simple_strtoul(buf, NULL, 10); \
142 \
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100143 mutex_lock(&data->update_lock); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144 data->value = val; \
145 lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100146 mutex_unlock(&data->update_lock); \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 return count; \
148}
149
150set(temp_min, LM77_REG_TEMP_MIN);
151set(temp_max, LM77_REG_TEMP_MAX);
152
153/* hysteresis is stored as a relative value on the chip, so it has to be
154 converted first */
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400155static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156{
157 struct i2c_client *client = to_i2c_client(dev);
158 struct lm77_data *data = i2c_get_clientdata(client);
159 unsigned long val = simple_strtoul(buf, NULL, 10);
160
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100161 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 data->temp_hyst = data->temp_crit - val;
163 lm77_write_value(client, LM77_REG_TEMP_HYST,
164 LM77_TEMP_TO_REG(data->temp_hyst));
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100165 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 return count;
167}
168
169/* preserve hysteresis when setting T_crit */
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400170static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171{
172 struct i2c_client *client = to_i2c_client(dev);
173 struct lm77_data *data = i2c_get_clientdata(client);
174 long val = simple_strtoul(buf, NULL, 10);
175 int oldcrithyst;
176
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100177 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 oldcrithyst = data->temp_crit - data->temp_hyst;
179 data->temp_crit = val;
180 data->temp_hyst = data->temp_crit - oldcrithyst;
181 lm77_write_value(client, LM77_REG_TEMP_CRIT,
182 LM77_TEMP_TO_REG(data->temp_crit));
183 lm77_write_value(client, LM77_REG_TEMP_HYST,
184 LM77_TEMP_TO_REG(data->temp_hyst));
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100185 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 return count;
187}
188
189static DEVICE_ATTR(temp1_input, S_IRUGO,
190 show_temp_input, NULL);
191static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
192 show_temp_crit, set_temp_crit);
193static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
194 show_temp_min, set_temp_min);
195static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
196 show_temp_max, set_temp_max);
197
198static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
199 show_temp_crit_hyst, set_temp_crit_hyst);
200static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
201 show_temp_min_hyst, NULL);
202static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
203 show_temp_max_hyst, NULL);
204
205static DEVICE_ATTR(alarms, S_IRUGO,
206 show_alarms, NULL);
207
208static int lm77_attach_adapter(struct i2c_adapter *adapter)
209{
210 if (!(adapter->class & I2C_CLASS_HWMON))
211 return 0;
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200212 return i2c_probe(adapter, &addr_data, lm77_detect);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213}
214
Mark M. Hoffman0501a382006-09-24 21:14:35 +0200215static struct attribute *lm77_attributes[] = {
216 &dev_attr_temp1_input.attr,
217 &dev_attr_temp1_crit.attr,
218 &dev_attr_temp1_min.attr,
219 &dev_attr_temp1_max.attr,
220 &dev_attr_temp1_crit_hyst.attr,
221 &dev_attr_temp1_min_hyst.attr,
222 &dev_attr_temp1_max_hyst.attr,
223 &dev_attr_alarms.attr,
224
225 NULL
226};
227
228static const struct attribute_group lm77_group = {
229 .attrs = lm77_attributes,
230};
231
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200232/* This function is called by i2c_probe */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233static int lm77_detect(struct i2c_adapter *adapter, int address, int kind)
234{
235 struct i2c_client *new_client;
236 struct lm77_data *data;
237 int err = 0;
238 const char *name = "";
239
240 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
241 I2C_FUNC_SMBUS_WORD_DATA))
242 goto exit;
243
244 /* OK. For now, we presume we have a valid client. We now create the
245 client structure, even though we cannot fill it completely yet.
246 But it allows us to access lm77_{read,write}_value. */
Deepak Saxenaba9c2e82005-10-17 23:08:32 +0200247 if (!(data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 err = -ENOMEM;
249 goto exit;
250 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251
252 new_client = &data->client;
253 i2c_set_clientdata(new_client, data);
254 new_client->addr = address;
255 new_client->adapter = adapter;
256 new_client->driver = &lm77_driver;
257 new_client->flags = 0;
258
259 /* Here comes the remaining detection. Since the LM77 has no
260 register dedicated to identification, we have to rely on the
261 following tricks:
262
263 1. the high 4 bits represent the sign and thus they should
264 always be the same
265 2. the high 3 bits are unused in the configuration register
266 3. addresses 0x06 and 0x07 return the last read value
267 4. registers cycling over 8-address boundaries
268
269 Word-sized registers are high-byte first. */
270 if (kind < 0) {
271 int i, cur, conf, hyst, crit, min, max;
272
273 /* addresses cycling */
274 cur = i2c_smbus_read_word_data(new_client, 0);
275 conf = i2c_smbus_read_byte_data(new_client, 1);
276 hyst = i2c_smbus_read_word_data(new_client, 2);
277 crit = i2c_smbus_read_word_data(new_client, 3);
278 min = i2c_smbus_read_word_data(new_client, 4);
279 max = i2c_smbus_read_word_data(new_client, 5);
280 for (i = 8; i <= 0xff; i += 8)
281 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
282 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
283 || i2c_smbus_read_word_data(new_client, i + 3) != crit
284 || i2c_smbus_read_word_data(new_client, i + 4) != min
285 || i2c_smbus_read_word_data(new_client, i + 5) != max)
286 goto exit_free;
287
288 /* sign bits */
289 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
290 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
291 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
292 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
293 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
294 goto exit_free;
295
296 /* unused bits */
297 if (conf & 0xe0)
298 goto exit_free;
299
300 /* 0x06 and 0x07 return the last read value */
301 cur = i2c_smbus_read_word_data(new_client, 0);
302 if (i2c_smbus_read_word_data(new_client, 6) != cur
303 || i2c_smbus_read_word_data(new_client, 7) != cur)
304 goto exit_free;
305 hyst = i2c_smbus_read_word_data(new_client, 2);
306 if (i2c_smbus_read_word_data(new_client, 6) != hyst
307 || i2c_smbus_read_word_data(new_client, 7) != hyst)
308 goto exit_free;
309 min = i2c_smbus_read_word_data(new_client, 4);
310 if (i2c_smbus_read_word_data(new_client, 6) != min
311 || i2c_smbus_read_word_data(new_client, 7) != min)
312 goto exit_free;
313
314 }
315
316 /* Determine the chip type - only one kind supported! */
317 if (kind <= 0)
318 kind = lm77;
319
320 if (kind == lm77) {
321 name = "lm77";
322 }
323
324 /* Fill in the remaining client fields and put it into the global list */
325 strlcpy(new_client->name, name, I2C_NAME_SIZE);
326 data->valid = 0;
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100327 mutex_init(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328
329 /* Tell the I2C layer a new client has arrived */
330 if ((err = i2c_attach_client(new_client)))
331 goto exit_free;
332
333 /* Initialize the LM77 chip */
334 lm77_init_client(new_client);
335
336 /* Register sysfs hooks */
Mark M. Hoffman0501a382006-09-24 21:14:35 +0200337 if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group)))
338 goto exit_detach;
339
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400340 data->class_dev = hwmon_device_register(&new_client->dev);
341 if (IS_ERR(data->class_dev)) {
342 err = PTR_ERR(data->class_dev);
Mark M. Hoffman0501a382006-09-24 21:14:35 +0200343 goto exit_remove;
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400344 }
345
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 return 0;
347
Mark M. Hoffman0501a382006-09-24 21:14:35 +0200348exit_remove:
349 sysfs_remove_group(&new_client->dev.kobj, &lm77_group);
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400350exit_detach:
351 i2c_detach_client(new_client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352exit_free:
353 kfree(data);
354exit:
355 return err;
356}
357
358static int lm77_detach_client(struct i2c_client *client)
359{
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400360 struct lm77_data *data = i2c_get_clientdata(client);
361 hwmon_device_unregister(data->class_dev);
Mark M. Hoffman0501a382006-09-24 21:14:35 +0200362 sysfs_remove_group(&client->dev.kobj, &lm77_group);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 i2c_detach_client(client);
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400364 kfree(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700365 return 0;
366}
367
368/* All registers are word-sized, except for the configuration register.
369 The LM77 uses the high-byte first convention. */
370static u16 lm77_read_value(struct i2c_client *client, u8 reg)
371{
372 if (reg == LM77_REG_CONF)
373 return i2c_smbus_read_byte_data(client, reg);
374 else
375 return swab16(i2c_smbus_read_word_data(client, reg));
376}
377
378static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
379{
380 if (reg == LM77_REG_CONF)
381 return i2c_smbus_write_byte_data(client, reg, value);
382 else
383 return i2c_smbus_write_word_data(client, reg, swab16(value));
384}
385
386static void lm77_init_client(struct i2c_client *client)
387{
388 /* Initialize the LM77 chip - turn off shutdown mode */
389 int conf = lm77_read_value(client, LM77_REG_CONF);
390 if (conf & 1)
391 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
392}
393
394static struct lm77_data *lm77_update_device(struct device *dev)
395{
396 struct i2c_client *client = to_i2c_client(dev);
397 struct lm77_data *data = i2c_get_clientdata(client);
398
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100399 mutex_lock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400
401 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
402 || !data->valid) {
403 dev_dbg(&client->dev, "Starting lm77 update\n");
404 data->temp_input =
405 LM77_TEMP_FROM_REG(lm77_read_value(client,
406 LM77_REG_TEMP));
407 data->temp_hyst =
408 LM77_TEMP_FROM_REG(lm77_read_value(client,
409 LM77_REG_TEMP_HYST));
410 data->temp_crit =
411 LM77_TEMP_FROM_REG(lm77_read_value(client,
412 LM77_REG_TEMP_CRIT));
413 data->temp_min =
414 LM77_TEMP_FROM_REG(lm77_read_value(client,
415 LM77_REG_TEMP_MIN));
416 data->temp_max =
417 LM77_TEMP_FROM_REG(lm77_read_value(client,
418 LM77_REG_TEMP_MAX));
419 data->alarms =
420 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
421 data->last_updated = jiffies;
422 data->valid = 1;
423 }
424
Ingo Molnar9a61bf62006-01-18 23:19:26 +0100425 mutex_unlock(&data->update_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 return data;
428}
429
430static int __init sensors_lm77_init(void)
431{
432 return i2c_add_driver(&lm77_driver);
433}
434
435static void __exit sensors_lm77_exit(void)
436{
437 i2c_del_driver(&lm77_driver);
438}
439
440MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
441MODULE_DESCRIPTION("LM77 driver");
442MODULE_LICENSE("GPL");
443
444module_init(sensors_lm77_init);
445module_exit(sensors_lm77_exit);