Commit | Line | Data |
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1da177e4 | 1 | /* |
02fe2fd9 GR |
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 | */ | |
1da177e4 | 27 | |
1da177e4 LT |
28 | #include <linux/module.h> |
29 | #include <linux/init.h> | |
30 | #include <linux/slab.h> | |
31 | #include <linux/jiffies.h> | |
32 | #include <linux/i2c.h> | |
943b0830 | 33 | #include <linux/hwmon.h> |
1f52af0f | 34 | #include <linux/hwmon-sysfs.h> |
943b0830 | 35 | #include <linux/err.h> |
9a61bf63 | 36 | #include <linux/mutex.h> |
1da177e4 LT |
37 | |
38 | /* Addresses to scan */ | |
25e9c86d MH |
39 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
40 | I2C_CLIENT_END }; | |
1da177e4 | 41 | |
1da177e4 LT |
42 | /* The LM77 registers */ |
43 | #define LM77_REG_TEMP 0x00 | |
44 | #define LM77_REG_CONF 0x01 | |
45 | #define LM77_REG_TEMP_HYST 0x02 | |
46 | #define LM77_REG_TEMP_CRIT 0x03 | |
47 | #define LM77_REG_TEMP_MIN 0x04 | |
48 | #define LM77_REG_TEMP_MAX 0x05 | |
49 | ||
50 | /* Each client has this additional data */ | |
51 | struct lm77_data { | |
02fe2fd9 | 52 | struct device *hwmon_dev; |
9a61bf63 | 53 | struct mutex update_lock; |
1da177e4 LT |
54 | char valid; |
55 | unsigned long last_updated; /* In jiffies */ | |
56 | int temp_input; /* Temperatures */ | |
57 | int temp_crit; | |
58 | int temp_min; | |
59 | int temp_max; | |
60 | int temp_hyst; | |
61 | u8 alarms; | |
62 | }; | |
63 | ||
a189dd62 JD |
64 | static int lm77_probe(struct i2c_client *client, |
65 | const struct i2c_device_id *id); | |
310ec792 | 66 | static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info); |
1da177e4 | 67 | static void lm77_init_client(struct i2c_client *client); |
a189dd62 | 68 | static int lm77_remove(struct i2c_client *client); |
1da177e4 LT |
69 | static u16 lm77_read_value(struct i2c_client *client, u8 reg); |
70 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value); | |
71 | ||
72 | static struct lm77_data *lm77_update_device(struct device *dev); | |
73 | ||
74 | ||
a189dd62 | 75 | static const struct i2c_device_id lm77_id[] = { |
1f86df49 | 76 | { "lm77", 0 }, |
a189dd62 JD |
77 | { } |
78 | }; | |
79 | MODULE_DEVICE_TABLE(i2c, lm77_id); | |
80 | ||
1da177e4 LT |
81 | /* This is the driver that will be inserted */ |
82 | static struct i2c_driver lm77_driver = { | |
a189dd62 | 83 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 84 | .driver = { |
cdaf7934 LR |
85 | .name = "lm77", |
86 | }, | |
a189dd62 JD |
87 | .probe = lm77_probe, |
88 | .remove = lm77_remove, | |
89 | .id_table = lm77_id, | |
90 | .detect = lm77_detect, | |
c3813d6a | 91 | .address_list = normal_i2c, |
1da177e4 LT |
92 | }; |
93 | ||
94 | /* straight from the datasheet */ | |
95 | #define LM77_TEMP_MIN (-55000) | |
96 | #define LM77_TEMP_MAX 125000 | |
97 | ||
02fe2fd9 GR |
98 | /* |
99 | * In the temperature registers, the low 3 bits are not part of the | |
100 | * temperature values; they are the status bits. | |
101 | */ | |
413b6451 | 102 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 | 103 | { |
2a844c14 | 104 | int ntemp = clamp_val(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); |
413b6451 | 105 | return (ntemp / 500) * 8; |
1da177e4 LT |
106 | } |
107 | ||
413b6451 | 108 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 109 | { |
413b6451 | 110 | return (reg / 8) * 500; |
1da177e4 LT |
111 | } |
112 | ||
113 | /* sysfs stuff */ | |
114 | ||
115 | /* read routines for temperature limits */ | |
116 | #define show(value) \ | |
02fe2fd9 GR |
117 | static ssize_t show_##value(struct device *dev, \ |
118 | struct device_attribute *attr, \ | |
119 | char *buf) \ | |
1da177e4 LT |
120 | { \ |
121 | struct lm77_data *data = lm77_update_device(dev); \ | |
122 | return sprintf(buf, "%d\n", data->value); \ | |
123 | } | |
124 | ||
125 | show(temp_input); | |
126 | show(temp_crit); | |
127 | show(temp_min); | |
128 | show(temp_max); | |
1da177e4 LT |
129 | |
130 | /* read routines for hysteresis values */ | |
02fe2fd9 GR |
131 | static ssize_t show_temp_crit_hyst(struct device *dev, |
132 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
133 | { |
134 | struct lm77_data *data = lm77_update_device(dev); | |
135 | return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); | |
136 | } | |
02fe2fd9 GR |
137 | static ssize_t show_temp_min_hyst(struct device *dev, |
138 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
139 | { |
140 | struct lm77_data *data = lm77_update_device(dev); | |
141 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
142 | } | |
02fe2fd9 GR |
143 | static ssize_t show_temp_max_hyst(struct device *dev, |
144 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
145 | { |
146 | struct lm77_data *data = lm77_update_device(dev); | |
147 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
148 | } | |
149 | ||
150 | /* write routines */ | |
151 | #define set(value, reg) \ | |
02fe2fd9 GR |
152 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \ |
153 | const char *buf, size_t count) \ | |
154 | { \ | |
155 | struct i2c_client *client = to_i2c_client(dev); \ | |
156 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
157 | long val; \ | |
158 | int err = kstrtol(buf, 10, &val); \ | |
159 | if (err) \ | |
160 | return err; \ | |
161 | \ | |
162 | mutex_lock(&data->update_lock); \ | |
163 | data->value = val; \ | |
164 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
165 | mutex_unlock(&data->update_lock); \ | |
166 | return count; \ | |
1da177e4 LT |
167 | } |
168 | ||
169 | set(temp_min, LM77_REG_TEMP_MIN); | |
170 | set(temp_max, LM77_REG_TEMP_MAX); | |
171 | ||
02fe2fd9 GR |
172 | /* |
173 | * hysteresis is stored as a relative value on the chip, so it has to be | |
174 | * converted first | |
175 | */ | |
176 | static ssize_t set_temp_crit_hyst(struct device *dev, | |
177 | struct device_attribute *attr, | |
178 | const char *buf, size_t count) | |
1da177e4 LT |
179 | { |
180 | struct i2c_client *client = to_i2c_client(dev); | |
181 | struct lm77_data *data = i2c_get_clientdata(client); | |
02fe2fd9 GR |
182 | unsigned long val; |
183 | int err; | |
184 | ||
185 | err = kstrtoul(buf, 10, &val); | |
186 | if (err) | |
187 | return err; | |
1da177e4 | 188 | |
9a61bf63 | 189 | mutex_lock(&data->update_lock); |
1da177e4 LT |
190 | data->temp_hyst = data->temp_crit - val; |
191 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
192 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 193 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
194 | return count; |
195 | } | |
196 | ||
197 | /* preserve hysteresis when setting T_crit */ | |
02fe2fd9 GR |
198 | static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, |
199 | const char *buf, size_t count) | |
1da177e4 LT |
200 | { |
201 | struct i2c_client *client = to_i2c_client(dev); | |
202 | struct lm77_data *data = i2c_get_clientdata(client); | |
1da177e4 | 203 | int oldcrithyst; |
02fe2fd9 GR |
204 | unsigned long val; |
205 | int err; | |
206 | ||
207 | err = kstrtoul(buf, 10, &val); | |
208 | if (err) | |
209 | return err; | |
210 | ||
9a61bf63 | 211 | mutex_lock(&data->update_lock); |
1da177e4 LT |
212 | oldcrithyst = data->temp_crit - data->temp_hyst; |
213 | data->temp_crit = val; | |
214 | data->temp_hyst = data->temp_crit - oldcrithyst; | |
215 | lm77_write_value(client, LM77_REG_TEMP_CRIT, | |
216 | LM77_TEMP_TO_REG(data->temp_crit)); | |
217 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
218 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
9a61bf63 | 219 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
220 | return count; |
221 | } | |
222 | ||
1f52af0f JD |
223 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
224 | char *buf) | |
225 | { | |
226 | int bitnr = to_sensor_dev_attr(attr)->index; | |
227 | struct lm77_data *data = lm77_update_device(dev); | |
228 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
229 | } | |
230 | ||
1da177e4 LT |
231 | static DEVICE_ATTR(temp1_input, S_IRUGO, |
232 | show_temp_input, NULL); | |
233 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
234 | show_temp_crit, set_temp_crit); | |
235 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
236 | show_temp_min, set_temp_min); | |
237 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
238 | show_temp_max, set_temp_max); | |
239 | ||
240 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
241 | show_temp_crit_hyst, set_temp_crit_hyst); | |
242 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
243 | show_temp_min_hyst, NULL); | |
244 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
245 | show_temp_max_hyst, NULL); | |
246 | ||
1f52af0f JD |
247 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
248 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
249 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 | 250 | |
0501a381 MH |
251 | static struct attribute *lm77_attributes[] = { |
252 | &dev_attr_temp1_input.attr, | |
253 | &dev_attr_temp1_crit.attr, | |
254 | &dev_attr_temp1_min.attr, | |
255 | &dev_attr_temp1_max.attr, | |
256 | &dev_attr_temp1_crit_hyst.attr, | |
257 | &dev_attr_temp1_min_hyst.attr, | |
258 | &dev_attr_temp1_max_hyst.attr, | |
1f52af0f JD |
259 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
260 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
261 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
262 | NULL |
263 | }; | |
264 | ||
265 | static const struct attribute_group lm77_group = { | |
266 | .attrs = lm77_attributes, | |
267 | }; | |
268 | ||
a189dd62 | 269 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
efd2d117 | 270 | static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info) |
1da177e4 | 271 | { |
efd2d117 | 272 | struct i2c_adapter *adapter = client->adapter; |
747d9bed | 273 | int i, cur, conf, hyst, crit, min, max; |
1da177e4 LT |
274 | |
275 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
276 | I2C_FUNC_SMBUS_WORD_DATA)) | |
a189dd62 | 277 | return -ENODEV; |
1da177e4 | 278 | |
02fe2fd9 GR |
279 | /* |
280 | * Here comes the remaining detection. Since the LM77 has no | |
281 | * register dedicated to identification, we have to rely on the | |
282 | * following tricks: | |
283 | * | |
284 | * 1. the high 4 bits represent the sign and thus they should | |
285 | * always be the same | |
286 | * 2. the high 3 bits are unused in the configuration register | |
287 | * 3. addresses 0x06 and 0x07 return the last read value | |
288 | * 4. registers cycling over 8-address boundaries | |
289 | * | |
290 | * Word-sized registers are high-byte first. | |
291 | */ | |
1da177e4 | 292 | |
747d9bed | 293 | /* addresses cycling */ |
efd2d117 GR |
294 | cur = i2c_smbus_read_word_data(client, 0); |
295 | conf = i2c_smbus_read_byte_data(client, 1); | |
296 | hyst = i2c_smbus_read_word_data(client, 2); | |
297 | crit = i2c_smbus_read_word_data(client, 3); | |
298 | min = i2c_smbus_read_word_data(client, 4); | |
299 | max = i2c_smbus_read_word_data(client, 5); | |
747d9bed | 300 | for (i = 8; i <= 0xff; i += 8) { |
efd2d117 GR |
301 | if (i2c_smbus_read_byte_data(client, i + 1) != conf |
302 | || i2c_smbus_read_word_data(client, i + 2) != hyst | |
303 | || i2c_smbus_read_word_data(client, i + 3) != crit | |
304 | || i2c_smbus_read_word_data(client, i + 4) != min | |
305 | || i2c_smbus_read_word_data(client, i + 5) != max) | |
a189dd62 | 306 | return -ENODEV; |
747d9bed | 307 | } |
1da177e4 | 308 | |
747d9bed JD |
309 | /* sign bits */ |
310 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
311 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
312 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
313 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
314 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
315 | return -ENODEV; | |
1da177e4 | 316 | |
747d9bed JD |
317 | /* unused bits */ |
318 | if (conf & 0xe0) | |
319 | return -ENODEV; | |
320 | ||
321 | /* 0x06 and 0x07 return the last read value */ | |
efd2d117 GR |
322 | cur = i2c_smbus_read_word_data(client, 0); |
323 | if (i2c_smbus_read_word_data(client, 6) != cur | |
324 | || i2c_smbus_read_word_data(client, 7) != cur) | |
747d9bed | 325 | return -ENODEV; |
efd2d117 GR |
326 | hyst = i2c_smbus_read_word_data(client, 2); |
327 | if (i2c_smbus_read_word_data(client, 6) != hyst | |
328 | || i2c_smbus_read_word_data(client, 7) != hyst) | |
747d9bed | 329 | return -ENODEV; |
efd2d117 GR |
330 | min = i2c_smbus_read_word_data(client, 4); |
331 | if (i2c_smbus_read_word_data(client, 6) != min | |
332 | || i2c_smbus_read_word_data(client, 7) != min) | |
747d9bed | 333 | return -ENODEV; |
1da177e4 | 334 | |
a189dd62 | 335 | strlcpy(info->type, "lm77", I2C_NAME_SIZE); |
1da177e4 | 336 | |
a189dd62 JD |
337 | return 0; |
338 | } | |
339 | ||
efd2d117 | 340 | static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id) |
a189dd62 | 341 | { |
efd2d117 | 342 | struct device *dev = &client->dev; |
a189dd62 JD |
343 | struct lm77_data *data; |
344 | int err; | |
345 | ||
52714c04 GR |
346 | data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL); |
347 | if (!data) | |
348 | return -ENOMEM; | |
1da177e4 | 349 | |
efd2d117 | 350 | i2c_set_clientdata(client, data); |
1da177e4 | 351 | data->valid = 0; |
9a61bf63 | 352 | mutex_init(&data->update_lock); |
1da177e4 | 353 | |
1da177e4 | 354 | /* Initialize the LM77 chip */ |
efd2d117 | 355 | lm77_init_client(client); |
1da177e4 LT |
356 | |
357 | /* Register sysfs hooks */ | |
efd2d117 | 358 | err = sysfs_create_group(&dev->kobj, &lm77_group); |
02fe2fd9 | 359 | if (err) |
52714c04 | 360 | return err; |
0501a381 | 361 | |
efd2d117 | 362 | data->hwmon_dev = hwmon_device_register(dev); |
1beeffe4 TJ |
363 | if (IS_ERR(data->hwmon_dev)) { |
364 | err = PTR_ERR(data->hwmon_dev); | |
0501a381 | 365 | goto exit_remove; |
943b0830 MH |
366 | } |
367 | ||
1da177e4 LT |
368 | return 0; |
369 | ||
0501a381 | 370 | exit_remove: |
efd2d117 | 371 | sysfs_remove_group(&dev->kobj, &lm77_group); |
1da177e4 LT |
372 | return err; |
373 | } | |
374 | ||
a189dd62 | 375 | static int lm77_remove(struct i2c_client *client) |
1da177e4 | 376 | { |
943b0830 | 377 | struct lm77_data *data = i2c_get_clientdata(client); |
1beeffe4 | 378 | hwmon_device_unregister(data->hwmon_dev); |
0501a381 | 379 | sysfs_remove_group(&client->dev.kobj, &lm77_group); |
1da177e4 LT |
380 | return 0; |
381 | } | |
382 | ||
02fe2fd9 GR |
383 | /* |
384 | * All registers are word-sized, except for the configuration register. | |
385 | * The LM77 uses the high-byte first convention. | |
386 | */ | |
1da177e4 LT |
387 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) |
388 | { | |
389 | if (reg == LM77_REG_CONF) | |
390 | return i2c_smbus_read_byte_data(client, reg); | |
391 | else | |
90f4102c | 392 | return i2c_smbus_read_word_swapped(client, reg); |
1da177e4 LT |
393 | } |
394 | ||
395 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
396 | { | |
397 | if (reg == LM77_REG_CONF) | |
398 | return i2c_smbus_write_byte_data(client, reg, value); | |
399 | else | |
90f4102c | 400 | return i2c_smbus_write_word_swapped(client, reg, value); |
1da177e4 LT |
401 | } |
402 | ||
403 | static void lm77_init_client(struct i2c_client *client) | |
404 | { | |
405 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
406 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
407 | if (conf & 1) | |
408 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
409 | } | |
410 | ||
411 | static struct lm77_data *lm77_update_device(struct device *dev) | |
412 | { | |
413 | struct i2c_client *client = to_i2c_client(dev); | |
414 | struct lm77_data *data = i2c_get_clientdata(client); | |
415 | ||
9a61bf63 | 416 | mutex_lock(&data->update_lock); |
1da177e4 LT |
417 | |
418 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
419 | || !data->valid) { | |
420 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
421 | data->temp_input = | |
422 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
423 | LM77_REG_TEMP)); | |
424 | data->temp_hyst = | |
425 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
426 | LM77_REG_TEMP_HYST)); | |
427 | data->temp_crit = | |
428 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
429 | LM77_REG_TEMP_CRIT)); | |
430 | data->temp_min = | |
431 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
432 | LM77_REG_TEMP_MIN)); | |
433 | data->temp_max = | |
434 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
435 | LM77_REG_TEMP_MAX)); | |
436 | data->alarms = | |
437 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
438 | data->last_updated = jiffies; | |
439 | data->valid = 1; | |
440 | } | |
441 | ||
9a61bf63 | 442 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
443 | |
444 | return data; | |
445 | } | |
446 | ||
f0967eea | 447 | module_i2c_driver(lm77_driver); |
1da177e4 LT |
448 | |
449 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
450 | MODULE_DESCRIPTION("LM77 driver"); | |
451 | MODULE_LICENSE("GPL"); |