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1/*
2 * lm92 - Hardware monitoring driver
3 * Copyright (C) 2005-2008 Jean Delvare <khali@linux-fr.org>
4 *
5 * Based on the lm90 driver, with some ideas taken from the lm_sensors
6 * lm92 driver as well.
7 *
8 * The LM92 is a sensor chip made by National Semiconductor. It reports
9 * its own temperature with a 0.0625 deg resolution and a 0.33 deg
10 * accuracy. Complete datasheet can be obtained from National's website
11 * at:
12 * http://www.national.com/pf/LM/LM92.html
13 *
14 * This driver also supports the MAX6635 sensor chip made by Maxim.
15 * This chip is compatible with the LM92, but has a lesser accuracy
16 * (1.0 deg). Complete datasheet can be obtained from Maxim's website
17 * at:
18 * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074
19 *
20 * Since the LM92 was the first chipset supported by this driver, most
21 * comments will refer to this chipset, but are actually general and
22 * concern all supported chipsets, unless mentioned otherwise.
23 *
24 * Support could easily be added for the National Semiconductor LM76
25 * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible
26 * with the LM92.
27 *
28 * This program is free software; you can redistribute it and/or modify
29 * it under the terms of the GNU General Public License as published by
30 * the Free Software Foundation; either version 2 of the License, or
31 * (at your option) any later version.
32 *
33 * This program is distributed in the hope that it will be useful,
34 * but WITHOUT ANY WARRANTY; without even the implied warranty of
35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
36 * GNU General Public License for more details.
37 *
38 * You should have received a copy of the GNU General Public License
39 * along with this program; if not, write to the Free Software
40 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
41 */
42
43#include <linux/module.h>
44#include <linux/init.h>
45#include <linux/slab.h>
46#include <linux/i2c.h>
47#include <linux/hwmon.h>
48#include <linux/hwmon-sysfs.h>
49#include <linux/err.h>
50#include <linux/mutex.h>
51
52/* The LM92 and MAX6635 have 2 two-state pins for address selection,
53 resulting in 4 possible addresses. */
54static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
55 I2C_CLIENT_END };
56
57/* The LM92 registers */
58#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
59#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
60#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
61#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
62#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
63#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
64#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
65
66/* The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
67 left-justified in 16-bit registers. No rounding is done, with such
68 a resolution it's just not worth it. Note that the MAX6635 doesn't
69 make use of the 4 lower bits for limits (i.e. effective resolution
70 for limits is 1 degree Celsius). */
71static inline int TEMP_FROM_REG(s16 reg)
72{
73 return reg / 8 * 625 / 10;
74}
75
76static inline s16 TEMP_TO_REG(int val)
77{
78 if (val <= -60000)
79 return -60000 * 10 / 625 * 8;
80 if (val >= 160000)
81 return 160000 * 10 / 625 * 8;
82 return val * 10 / 625 * 8;
83}
84
85/* Alarm flags are stored in the 3 LSB of the temperature register */
86static inline u8 ALARMS_FROM_REG(s16 reg)
87{
88 return reg & 0x0007;
89}
90
91/* Driver data (common to all clients) */
92static struct i2c_driver lm92_driver;
93
94/* Client data (each client gets its own) */
95struct lm92_data {
96 struct device *hwmon_dev;
97 struct mutex update_lock;
98 char valid; /* zero until following fields are valid */
99 unsigned long last_updated; /* in jiffies */
100
101 /* registers values */
102 s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
103};
104
105
106/*
107 * Sysfs attributes and callback functions
108 */
109
110static struct lm92_data *lm92_update_device(struct device *dev)
111{
112 struct i2c_client *client = to_i2c_client(dev);
113 struct lm92_data *data = i2c_get_clientdata(client);
114
115 mutex_lock(&data->update_lock);
116
117 if (time_after(jiffies, data->last_updated + HZ)
118 || !data->valid) {
119 dev_dbg(&client->dev, "Updating lm92 data\n");
120 data->temp1_input = swab16(i2c_smbus_read_word_data(client,
121 LM92_REG_TEMP));
122 data->temp1_hyst = swab16(i2c_smbus_read_word_data(client,
123 LM92_REG_TEMP_HYST));
124 data->temp1_crit = swab16(i2c_smbus_read_word_data(client,
125 LM92_REG_TEMP_CRIT));
126 data->temp1_min = swab16(i2c_smbus_read_word_data(client,
127 LM92_REG_TEMP_LOW));
128 data->temp1_max = swab16(i2c_smbus_read_word_data(client,
129 LM92_REG_TEMP_HIGH));
130
131 data->last_updated = jiffies;
132 data->valid = 1;
133 }
134
135 mutex_unlock(&data->update_lock);
136
137 return data;
138}
139
140#define show_temp(value) \
141static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
142{ \
143 struct lm92_data *data = lm92_update_device(dev); \
144 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
145}
146show_temp(temp1_input);
147show_temp(temp1_crit);
148show_temp(temp1_min);
149show_temp(temp1_max);
150
151#define set_temp(value, reg) \
152static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \
153 size_t count) \
154{ \
155 struct i2c_client *client = to_i2c_client(dev); \
156 struct lm92_data *data = i2c_get_clientdata(client); \
157 long val = simple_strtol(buf, NULL, 10); \
158 \
159 mutex_lock(&data->update_lock); \
160 data->value = TEMP_TO_REG(val); \
161 i2c_smbus_write_word_data(client, reg, swab16(data->value)); \
162 mutex_unlock(&data->update_lock); \
163 return count; \
164}
165set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
166set_temp(temp1_min, LM92_REG_TEMP_LOW);
167set_temp(temp1_max, LM92_REG_TEMP_HIGH);
168
169static ssize_t show_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
170{
171 struct lm92_data *data = lm92_update_device(dev);
172 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
173 - TEMP_FROM_REG(data->temp1_hyst));
174}
175static ssize_t show_temp1_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
176{
177 struct lm92_data *data = lm92_update_device(dev);
178 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
179 - TEMP_FROM_REG(data->temp1_hyst));
180}
181static ssize_t show_temp1_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
182{
183 struct lm92_data *data = lm92_update_device(dev);
184 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
185 + TEMP_FROM_REG(data->temp1_hyst));
186}
187
188static ssize_t set_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf,
189 size_t count)
190{
191 struct i2c_client *client = to_i2c_client(dev);
192 struct lm92_data *data = i2c_get_clientdata(client);
193 long val = simple_strtol(buf, NULL, 10);
194
195 mutex_lock(&data->update_lock);
196 data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
197 i2c_smbus_write_word_data(client, LM92_REG_TEMP_HYST,
198 swab16(TEMP_TO_REG(data->temp1_hyst)));
199 mutex_unlock(&data->update_lock);
200 return count;
201}
202
203static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
204{
205 struct lm92_data *data = lm92_update_device(dev);
206 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
207}
208
209static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
210 char *buf)
211{
212 int bitnr = to_sensor_dev_attr(attr)->index;
213 struct lm92_data *data = lm92_update_device(dev);
214 return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1);
215}
216
217static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
218static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit,
219 set_temp1_crit);
220static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst,
221 set_temp1_crit_hyst);
222static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min,
223 set_temp1_min);
224static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
225static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max,
226 set_temp1_max);
227static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
228static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
229static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
230static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
231static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
232
233
234/*
235 * Detection and registration
236 */
237
238static void lm92_init_client(struct i2c_client *client)
239{
240 u8 config;
241
242 /* Start the conversions if needed */
243 config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
244 if (config & 0x01)
245 i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
246 config & 0xFE);
247}
248
249/* The MAX6635 has no identification register, so we have to use tricks
250 to identify it reliably. This is somewhat slow.
251 Note that we do NOT rely on the 2 MSB of the configuration register
252 always reading 0, as suggested by the datasheet, because it was once
253 reported not to be true. */
254static int max6635_check(struct i2c_client *client)
255{
256 u16 temp_low, temp_high, temp_hyst, temp_crit;
257 u8 conf;
258 int i;
259
260 /* No manufacturer ID register, so a read from this address will
261 always return the last read value. */
262 temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
263 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
264 return 0;
265 temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
266 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
267 return 0;
268
269 /* Limits are stored as integer values (signed, 9-bit). */
270 if ((temp_low & 0x7f00) || (temp_high & 0x7f00))
271 return 0;
272 temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
273 temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
274 if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00))
275 return 0;
276
277 /* Registers addresses were found to cycle over 16-byte boundaries.
278 We don't test all registers with all offsets so as to save some
279 reads and time, but this should still be sufficient to dismiss
280 non-MAX6635 chips. */
281 conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
282 for (i=16; i<96; i*=2) {
283 if (temp_hyst != i2c_smbus_read_word_data(client,
284 LM92_REG_TEMP_HYST + i - 16)
285 || temp_crit != i2c_smbus_read_word_data(client,
286 LM92_REG_TEMP_CRIT + i)
287 || temp_low != i2c_smbus_read_word_data(client,
288 LM92_REG_TEMP_LOW + i + 16)
289 || temp_high != i2c_smbus_read_word_data(client,
290 LM92_REG_TEMP_HIGH + i + 32)
291 || conf != i2c_smbus_read_byte_data(client,
292 LM92_REG_CONFIG + i))
293 return 0;
294 }
295
296 return 1;
297}
298
299static struct attribute *lm92_attributes[] = {
300 &dev_attr_temp1_input.attr,
301 &dev_attr_temp1_crit.attr,
302 &dev_attr_temp1_crit_hyst.attr,
303 &dev_attr_temp1_min.attr,
304 &dev_attr_temp1_min_hyst.attr,
305 &dev_attr_temp1_max.attr,
306 &dev_attr_temp1_max_hyst.attr,
307 &dev_attr_alarms.attr,
308 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
309 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
310 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
311 NULL
312};
313
314static const struct attribute_group lm92_group = {
315 .attrs = lm92_attributes,
316};
317
318/* Return 0 if detection is successful, -ENODEV otherwise */
319static int lm92_detect(struct i2c_client *new_client,
320 struct i2c_board_info *info)
321{
322 struct i2c_adapter *adapter = new_client->adapter;
323 u8 config;
324 u16 man_id;
325
326 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
327 | I2C_FUNC_SMBUS_WORD_DATA))
328 return -ENODEV;
329
330 config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
331 man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
332
333 if ((config & 0xe0) == 0x00 && man_id == 0x0180)
334 pr_info("lm92: Found National Semiconductor LM92 chip\n");
335 else if (max6635_check(new_client))
336 pr_info("lm92: Found Maxim MAX6635 chip\n");
337 else
338 return -ENODEV;
339
340 strlcpy(info->type, "lm92", I2C_NAME_SIZE);
341
342 return 0;
343}
344
345static int lm92_probe(struct i2c_client *new_client,
346 const struct i2c_device_id *id)
347{
348 struct lm92_data *data;
349 int err;
350
351 data = kzalloc(sizeof(struct lm92_data), GFP_KERNEL);
352 if (!data) {
353 err = -ENOMEM;
354 goto exit;
355 }
356
357 i2c_set_clientdata(new_client, data);
358 data->valid = 0;
359 mutex_init(&data->update_lock);
360
361 /* Initialize the chipset */
362 lm92_init_client(new_client);
363
364 /* Register sysfs hooks */
365 if ((err = sysfs_create_group(&new_client->dev.kobj, &lm92_group)))
366 goto exit_free;
367
368 data->hwmon_dev = hwmon_device_register(&new_client->dev);
369 if (IS_ERR(data->hwmon_dev)) {
370 err = PTR_ERR(data->hwmon_dev);
371 goto exit_remove;
372 }
373
374 return 0;
375
376exit_remove:
377 sysfs_remove_group(&new_client->dev.kobj, &lm92_group);
378exit_free:
379 kfree(data);
380exit:
381 return err;
382}
383
384static int lm92_remove(struct i2c_client *client)
385{
386 struct lm92_data *data = i2c_get_clientdata(client);
387
388 hwmon_device_unregister(data->hwmon_dev);
389 sysfs_remove_group(&client->dev.kobj, &lm92_group);
390
391 kfree(data);
392 return 0;
393}
394
395
396/*
397 * Module and driver stuff
398 */
399
400static const struct i2c_device_id lm92_id[] = {
401 { "lm92", 0 },
402 /* max6635 could be added here */
403 { }
404};
405MODULE_DEVICE_TABLE(i2c, lm92_id);
406
407static struct i2c_driver lm92_driver = {
408 .class = I2C_CLASS_HWMON,
409 .driver = {
410 .name = "lm92",
411 },
412 .probe = lm92_probe,
413 .remove = lm92_remove,
414 .id_table = lm92_id,
415 .detect = lm92_detect,
416 .address_list = normal_i2c,
417};
418
419static int __init sensors_lm92_init(void)
420{
421 return i2c_add_driver(&lm92_driver);
422}
423
424static void __exit sensors_lm92_exit(void)
425{
426 i2c_del_driver(&lm92_driver);
427}
428
429MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
430MODULE_DESCRIPTION("LM92/MAX6635 driver");
431MODULE_LICENSE("GPL");
432
433module_init(sensors_lm92_init);
434module_exit(sensors_lm92_exit);
1/*
2 * lm92 - Hardware monitoring driver
3 * Copyright (C) 2005-2008 Jean Delvare <jdelvare@suse.de>
4 *
5 * Based on the lm90 driver, with some ideas taken from the lm_sensors
6 * lm92 driver as well.
7 *
8 * The LM92 is a sensor chip made by National Semiconductor. It reports
9 * its own temperature with a 0.0625 deg resolution and a 0.33 deg
10 * accuracy. Complete datasheet can be obtained from National's website
11 * at:
12 * http://www.national.com/pf/LM/LM92.html
13 *
14 * This driver also supports the MAX6635 sensor chip made by Maxim.
15 * This chip is compatible with the LM92, but has a lesser accuracy
16 * (1.0 deg). Complete datasheet can be obtained from Maxim's website
17 * at:
18 * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074
19 *
20 * Since the LM92 was the first chipset supported by this driver, most
21 * comments will refer to this chipset, but are actually general and
22 * concern all supported chipsets, unless mentioned otherwise.
23 *
24 * Support could easily be added for the National Semiconductor LM76
25 * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible
26 * with the LM92.
27 *
28 * This program is free software; you can redistribute it and/or modify
29 * it under the terms of the GNU General Public License as published by
30 * the Free Software Foundation; either version 2 of the License, or
31 * (at your option) any later version.
32 *
33 * This program is distributed in the hope that it will be useful,
34 * but WITHOUT ANY WARRANTY; without even the implied warranty of
35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
36 * GNU General Public License for more details.
37 *
38 * You should have received a copy of the GNU General Public License
39 * along with this program; if not, write to the Free Software
40 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
41 */
42
43#include <linux/module.h>
44#include <linux/init.h>
45#include <linux/slab.h>
46#include <linux/i2c.h>
47#include <linux/hwmon.h>
48#include <linux/hwmon-sysfs.h>
49#include <linux/err.h>
50#include <linux/mutex.h>
51#include <linux/jiffies.h>
52
53/*
54 * The LM92 and MAX6635 have 2 two-state pins for address selection,
55 * resulting in 4 possible addresses.
56 */
57static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
58 I2C_CLIENT_END };
59
60/* The LM92 registers */
61#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
62#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
63#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
64#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
65#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
66#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
67#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
68
69/*
70 * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
71 * left-justified in 16-bit registers. No rounding is done, with such
72 * a resolution it's just not worth it. Note that the MAX6635 doesn't
73 * make use of the 4 lower bits for limits (i.e. effective resolution
74 * for limits is 1 degree Celsius).
75 */
76static inline int TEMP_FROM_REG(s16 reg)
77{
78 return reg / 8 * 625 / 10;
79}
80
81static inline s16 TEMP_TO_REG(int val)
82{
83 if (val <= -60000)
84 return -60000 * 10 / 625 * 8;
85 if (val >= 160000)
86 return 160000 * 10 / 625 * 8;
87 return val * 10 / 625 * 8;
88}
89
90/* Alarm flags are stored in the 3 LSB of the temperature register */
91static inline u8 ALARMS_FROM_REG(s16 reg)
92{
93 return reg & 0x0007;
94}
95
96/* Driver data (common to all clients) */
97static struct i2c_driver lm92_driver;
98
99/* Client data (each client gets its own) */
100struct lm92_data {
101 struct device *hwmon_dev;
102 struct mutex update_lock;
103 char valid; /* zero until following fields are valid */
104 unsigned long last_updated; /* in jiffies */
105
106 /* registers values */
107 s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
108};
109
110
111/*
112 * Sysfs attributes and callback functions
113 */
114
115static struct lm92_data *lm92_update_device(struct device *dev)
116{
117 struct i2c_client *client = to_i2c_client(dev);
118 struct lm92_data *data = i2c_get_clientdata(client);
119
120 mutex_lock(&data->update_lock);
121
122 if (time_after(jiffies, data->last_updated + HZ)
123 || !data->valid) {
124 dev_dbg(&client->dev, "Updating lm92 data\n");
125 data->temp1_input = i2c_smbus_read_word_swapped(client,
126 LM92_REG_TEMP);
127 data->temp1_hyst = i2c_smbus_read_word_swapped(client,
128 LM92_REG_TEMP_HYST);
129 data->temp1_crit = i2c_smbus_read_word_swapped(client,
130 LM92_REG_TEMP_CRIT);
131 data->temp1_min = i2c_smbus_read_word_swapped(client,
132 LM92_REG_TEMP_LOW);
133 data->temp1_max = i2c_smbus_read_word_swapped(client,
134 LM92_REG_TEMP_HIGH);
135
136 data->last_updated = jiffies;
137 data->valid = 1;
138 }
139
140 mutex_unlock(&data->update_lock);
141
142 return data;
143}
144
145#define show_temp(value) \
146static ssize_t show_##value(struct device *dev, struct device_attribute *attr, \
147 char *buf) \
148{ \
149 struct lm92_data *data = lm92_update_device(dev); \
150 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
151}
152show_temp(temp1_input);
153show_temp(temp1_crit);
154show_temp(temp1_min);
155show_temp(temp1_max);
156
157#define set_temp(value, reg) \
158static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
159 const char *buf, \
160 size_t count) \
161{ \
162 struct i2c_client *client = to_i2c_client(dev); \
163 struct lm92_data *data = i2c_get_clientdata(client); \
164 long val; \
165 int err = kstrtol(buf, 10, &val); \
166 if (err) \
167 return err; \
168\
169 mutex_lock(&data->update_lock); \
170 data->value = TEMP_TO_REG(val); \
171 i2c_smbus_write_word_swapped(client, reg, data->value); \
172 mutex_unlock(&data->update_lock); \
173 return count; \
174}
175set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
176set_temp(temp1_min, LM92_REG_TEMP_LOW);
177set_temp(temp1_max, LM92_REG_TEMP_HIGH);
178
179static ssize_t show_temp1_crit_hyst(struct device *dev,
180 struct device_attribute *attr, char *buf)
181{
182 struct lm92_data *data = lm92_update_device(dev);
183 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
184 - TEMP_FROM_REG(data->temp1_hyst));
185}
186static ssize_t show_temp1_max_hyst(struct device *dev,
187 struct device_attribute *attr, char *buf)
188{
189 struct lm92_data *data = lm92_update_device(dev);
190 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
191 - TEMP_FROM_REG(data->temp1_hyst));
192}
193static ssize_t show_temp1_min_hyst(struct device *dev,
194 struct device_attribute *attr, char *buf)
195{
196 struct lm92_data *data = lm92_update_device(dev);
197 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
198 + TEMP_FROM_REG(data->temp1_hyst));
199}
200
201static ssize_t set_temp1_crit_hyst(struct device *dev,
202 struct device_attribute *attr,
203 const char *buf, size_t count)
204{
205 struct i2c_client *client = to_i2c_client(dev);
206 struct lm92_data *data = i2c_get_clientdata(client);
207 long val;
208 int err;
209
210 err = kstrtol(buf, 10, &val);
211 if (err)
212 return err;
213
214 mutex_lock(&data->update_lock);
215 data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
216 i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST,
217 TEMP_TO_REG(data->temp1_hyst));
218 mutex_unlock(&data->update_lock);
219 return count;
220}
221
222static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
223 char *buf)
224{
225 struct lm92_data *data = lm92_update_device(dev);
226 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
227}
228
229static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
230 char *buf)
231{
232 int bitnr = to_sensor_dev_attr(attr)->index;
233 struct lm92_data *data = lm92_update_device(dev);
234 return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1);
235}
236
237static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
238static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit,
239 set_temp1_crit);
240static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst,
241 set_temp1_crit_hyst);
242static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min,
243 set_temp1_min);
244static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
245static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max,
246 set_temp1_max);
247static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
248static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
249static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
250static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
251static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
252
253
254/*
255 * Detection and registration
256 */
257
258static void lm92_init_client(struct i2c_client *client)
259{
260 u8 config;
261
262 /* Start the conversions if needed */
263 config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
264 if (config & 0x01)
265 i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
266 config & 0xFE);
267}
268
269/*
270 * The MAX6635 has no identification register, so we have to use tricks
271 * to identify it reliably. This is somewhat slow.
272 * Note that we do NOT rely on the 2 MSB of the configuration register
273 * always reading 0, as suggested by the datasheet, because it was once
274 * reported not to be true.
275 */
276static int max6635_check(struct i2c_client *client)
277{
278 u16 temp_low, temp_high, temp_hyst, temp_crit;
279 u8 conf;
280 int i;
281
282 /*
283 * No manufacturer ID register, so a read from this address will
284 * always return the last read value.
285 */
286 temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
287 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
288 return 0;
289 temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
290 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
291 return 0;
292
293 /* Limits are stored as integer values (signed, 9-bit). */
294 if ((temp_low & 0x7f00) || (temp_high & 0x7f00))
295 return 0;
296 temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
297 temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
298 if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00))
299 return 0;
300
301 /*
302 * Registers addresses were found to cycle over 16-byte boundaries.
303 * We don't test all registers with all offsets so as to save some
304 * reads and time, but this should still be sufficient to dismiss
305 * non-MAX6635 chips.
306 */
307 conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
308 for (i = 16; i < 96; i *= 2) {
309 if (temp_hyst != i2c_smbus_read_word_data(client,
310 LM92_REG_TEMP_HYST + i - 16)
311 || temp_crit != i2c_smbus_read_word_data(client,
312 LM92_REG_TEMP_CRIT + i)
313 || temp_low != i2c_smbus_read_word_data(client,
314 LM92_REG_TEMP_LOW + i + 16)
315 || temp_high != i2c_smbus_read_word_data(client,
316 LM92_REG_TEMP_HIGH + i + 32)
317 || conf != i2c_smbus_read_byte_data(client,
318 LM92_REG_CONFIG + i))
319 return 0;
320 }
321
322 return 1;
323}
324
325static struct attribute *lm92_attributes[] = {
326 &dev_attr_temp1_input.attr,
327 &dev_attr_temp1_crit.attr,
328 &dev_attr_temp1_crit_hyst.attr,
329 &dev_attr_temp1_min.attr,
330 &dev_attr_temp1_min_hyst.attr,
331 &dev_attr_temp1_max.attr,
332 &dev_attr_temp1_max_hyst.attr,
333 &dev_attr_alarms.attr,
334 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
335 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
336 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
337 NULL
338};
339
340static const struct attribute_group lm92_group = {
341 .attrs = lm92_attributes,
342};
343
344/* Return 0 if detection is successful, -ENODEV otherwise */
345static int lm92_detect(struct i2c_client *new_client,
346 struct i2c_board_info *info)
347{
348 struct i2c_adapter *adapter = new_client->adapter;
349 u8 config;
350 u16 man_id;
351
352 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
353 | I2C_FUNC_SMBUS_WORD_DATA))
354 return -ENODEV;
355
356 config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
357 man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
358
359 if ((config & 0xe0) == 0x00 && man_id == 0x0180)
360 pr_info("lm92: Found National Semiconductor LM92 chip\n");
361 else if (max6635_check(new_client))
362 pr_info("lm92: Found Maxim MAX6635 chip\n");
363 else
364 return -ENODEV;
365
366 strlcpy(info->type, "lm92", I2C_NAME_SIZE);
367
368 return 0;
369}
370
371static int lm92_probe(struct i2c_client *new_client,
372 const struct i2c_device_id *id)
373{
374 struct lm92_data *data;
375 int err;
376
377 data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data),
378 GFP_KERNEL);
379 if (!data)
380 return -ENOMEM;
381
382 i2c_set_clientdata(new_client, data);
383 mutex_init(&data->update_lock);
384
385 /* Initialize the chipset */
386 lm92_init_client(new_client);
387
388 /* Register sysfs hooks */
389 err = sysfs_create_group(&new_client->dev.kobj, &lm92_group);
390 if (err)
391 return err;
392
393 data->hwmon_dev = hwmon_device_register(&new_client->dev);
394 if (IS_ERR(data->hwmon_dev)) {
395 err = PTR_ERR(data->hwmon_dev);
396 goto exit_remove;
397 }
398
399 return 0;
400
401exit_remove:
402 sysfs_remove_group(&new_client->dev.kobj, &lm92_group);
403 return err;
404}
405
406static int lm92_remove(struct i2c_client *client)
407{
408 struct lm92_data *data = i2c_get_clientdata(client);
409
410 hwmon_device_unregister(data->hwmon_dev);
411 sysfs_remove_group(&client->dev.kobj, &lm92_group);
412
413 return 0;
414}
415
416
417/*
418 * Module and driver stuff
419 */
420
421static const struct i2c_device_id lm92_id[] = {
422 { "lm92", 0 },
423 /* max6635 could be added here */
424 { }
425};
426MODULE_DEVICE_TABLE(i2c, lm92_id);
427
428static struct i2c_driver lm92_driver = {
429 .class = I2C_CLASS_HWMON,
430 .driver = {
431 .name = "lm92",
432 },
433 .probe = lm92_probe,
434 .remove = lm92_remove,
435 .id_table = lm92_id,
436 .detect = lm92_detect,
437 .address_list = normal_i2c,
438};
439
440module_i2c_driver(lm92_driver);
441
442MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
443MODULE_DESCRIPTION("LM92/MAX6635 driver");
444MODULE_LICENSE("GPL");