Commit | Line | Data |
---|---|---|
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. | |
02fe2fd9 | 22 | */ |
1da177e4 | 23 | |
1da177e4 LT |
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> | |
943b0830 | 29 | #include <linux/hwmon.h> |
1f52af0f | 30 | #include <linux/hwmon-sysfs.h> |
943b0830 | 31 | #include <linux/err.h> |
9a61bf63 | 32 | #include <linux/mutex.h> |
1da177e4 LT |
33 | |
34 | /* Addresses to scan */ | |
25e9c86d MH |
35 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
36 | I2C_CLIENT_END }; | |
1da177e4 | 37 | |
1da177e4 LT |
38 | /* The LM77 registers */ |
39 | #define LM77_REG_TEMP 0x00 | |
40 | #define LM77_REG_CONF 0x01 | |
41 | #define LM77_REG_TEMP_HYST 0x02 | |
42 | #define LM77_REG_TEMP_CRIT 0x03 | |
43 | #define LM77_REG_TEMP_MIN 0x04 | |
44 | #define LM77_REG_TEMP_MAX 0x05 | |
45 | ||
48dbd6ff GR |
46 | enum temp_index { |
47 | t_input = 0, | |
48 | t_crit, | |
49 | t_min, | |
50 | t_max, | |
51 | t_hyst, | |
52 | t_num_temp | |
53 | }; | |
54 | ||
55 | static const u8 temp_regs[t_num_temp] = { | |
56 | [t_input] = LM77_REG_TEMP, | |
57 | [t_min] = LM77_REG_TEMP_MIN, | |
58 | [t_max] = LM77_REG_TEMP_MAX, | |
59 | [t_crit] = LM77_REG_TEMP_CRIT, | |
60 | [t_hyst] = LM77_REG_TEMP_HYST, | |
61 | }; | |
62 | ||
1da177e4 LT |
63 | /* Each client has this additional data */ |
64 | struct lm77_data { | |
5975dfbf | 65 | struct i2c_client *client; |
9a61bf63 | 66 | struct mutex update_lock; |
1da177e4 LT |
67 | char valid; |
68 | unsigned long last_updated; /* In jiffies */ | |
48dbd6ff | 69 | int temp[t_num_temp]; /* index using temp_index */ |
1da177e4 LT |
70 | u8 alarms; |
71 | }; | |
72 | ||
1da177e4 LT |
73 | /* straight from the datasheet */ |
74 | #define LM77_TEMP_MIN (-55000) | |
75 | #define LM77_TEMP_MAX 125000 | |
76 | ||
02fe2fd9 GR |
77 | /* |
78 | * In the temperature registers, the low 3 bits are not part of the | |
79 | * temperature values; they are the status bits. | |
80 | */ | |
413b6451 | 81 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 | 82 | { |
99765db2 | 83 | return (temp / 500) * 8; |
1da177e4 LT |
84 | } |
85 | ||
413b6451 | 86 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 87 | { |
413b6451 | 88 | return (reg / 8) * 500; |
1da177e4 LT |
89 | } |
90 | ||
9f9edcd4 GR |
91 | /* |
92 | * All registers are word-sized, except for the configuration register. | |
93 | * The LM77 uses the high-byte first convention. | |
94 | */ | |
95 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
96 | { | |
97 | if (reg == LM77_REG_CONF) | |
98 | return i2c_smbus_read_byte_data(client, reg); | |
99 | else | |
100 | return i2c_smbus_read_word_swapped(client, reg); | |
101 | } | |
102 | ||
103 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
104 | { | |
105 | if (reg == LM77_REG_CONF) | |
106 | return i2c_smbus_write_byte_data(client, reg, value); | |
107 | else | |
108 | return i2c_smbus_write_word_swapped(client, reg, value); | |
109 | } | |
110 | ||
111 | static struct lm77_data *lm77_update_device(struct device *dev) | |
112 | { | |
5975dfbf GR |
113 | struct lm77_data *data = dev_get_drvdata(dev); |
114 | struct i2c_client *client = data->client; | |
48dbd6ff | 115 | int i; |
9f9edcd4 GR |
116 | |
117 | mutex_lock(&data->update_lock); | |
118 | ||
119 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
120 | || !data->valid) { | |
121 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
48dbd6ff GR |
122 | for (i = 0; i < t_num_temp; i++) { |
123 | data->temp[i] = | |
124 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
125 | temp_regs[i])); | |
126 | } | |
9f9edcd4 GR |
127 | data->alarms = |
128 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
129 | data->last_updated = jiffies; | |
130 | data->valid = 1; | |
131 | } | |
132 | ||
133 | mutex_unlock(&data->update_lock); | |
134 | ||
135 | return data; | |
136 | } | |
137 | ||
1da177e4 LT |
138 | /* sysfs stuff */ |
139 | ||
48dbd6ff GR |
140 | static ssize_t show_temp(struct device *dev, struct device_attribute *devattr, |
141 | char *buf) | |
1da177e4 | 142 | { |
48dbd6ff | 143 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
1da177e4 | 144 | struct lm77_data *data = lm77_update_device(dev); |
48dbd6ff GR |
145 | |
146 | return sprintf(buf, "%d\n", data->temp[attr->index]); | |
1da177e4 | 147 | } |
48dbd6ff GR |
148 | |
149 | static ssize_t show_temp_hyst(struct device *dev, | |
150 | struct device_attribute *devattr, char *buf) | |
1da177e4 | 151 | { |
48dbd6ff | 152 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
1da177e4 | 153 | struct lm77_data *data = lm77_update_device(dev); |
48dbd6ff GR |
154 | int nr = attr->index; |
155 | int temp; | |
1da177e4 | 156 | |
48dbd6ff GR |
157 | temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] : |
158 | data->temp[nr] - data->temp[t_hyst]; | |
1da177e4 | 159 | |
48dbd6ff GR |
160 | return sprintf(buf, "%d\n", temp); |
161 | } | |
1da177e4 | 162 | |
48dbd6ff GR |
163 | static ssize_t set_temp(struct device *dev, struct device_attribute *devattr, |
164 | const char *buf, size_t count) | |
1da177e4 | 165 | { |
48dbd6ff | 166 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
5975dfbf GR |
167 | struct lm77_data *data = dev_get_drvdata(dev); |
168 | struct i2c_client *client = data->client; | |
48dbd6ff GR |
169 | int nr = attr->index; |
170 | long val; | |
02fe2fd9 GR |
171 | int err; |
172 | ||
48dbd6ff | 173 | err = kstrtol(buf, 10, &val); |
02fe2fd9 GR |
174 | if (err) |
175 | return err; | |
1da177e4 | 176 | |
99765db2 | 177 | val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX); |
9a61bf63 | 178 | mutex_lock(&data->update_lock); |
48dbd6ff GR |
179 | data->temp[nr] = val; |
180 | lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val)); | |
9a61bf63 | 181 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
182 | return count; |
183 | } | |
184 | ||
48dbd6ff GR |
185 | /* |
186 | * hysteresis is stored as a relative value on the chip, so it has to be | |
187 | * converted first. | |
188 | */ | |
189 | static ssize_t set_temp_hyst(struct device *dev, | |
190 | struct device_attribute *devattr, | |
02fe2fd9 | 191 | const char *buf, size_t count) |
1da177e4 | 192 | { |
5975dfbf GR |
193 | struct lm77_data *data = dev_get_drvdata(dev); |
194 | struct i2c_client *client = data->client; | |
99765db2 | 195 | long val; |
02fe2fd9 GR |
196 | int err; |
197 | ||
99765db2 | 198 | err = kstrtol(buf, 10, &val); |
02fe2fd9 GR |
199 | if (err) |
200 | return err; | |
201 | ||
9a61bf63 | 202 | mutex_lock(&data->update_lock); |
99765db2 AL |
203 | val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX); |
204 | data->temp[t_hyst] = val; | |
48dbd6ff GR |
205 | lm77_write_value(client, LM77_REG_TEMP_HYST, |
206 | LM77_TEMP_TO_REG(data->temp[t_hyst])); | |
9a61bf63 | 207 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
208 | return count; |
209 | } | |
210 | ||
1f52af0f JD |
211 | static ssize_t show_alarm(struct device *dev, struct device_attribute *attr, |
212 | char *buf) | |
213 | { | |
214 | int bitnr = to_sensor_dev_attr(attr)->index; | |
215 | struct lm77_data *data = lm77_update_device(dev); | |
216 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
217 | } | |
218 | ||
48dbd6ff GR |
219 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input); |
220 | static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp, set_temp, | |
221 | t_crit); | |
222 | static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, | |
223 | t_min); | |
224 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, | |
225 | t_max); | |
226 | ||
227 | static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, | |
228 | set_temp_hyst, t_crit); | |
229 | static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp_hyst, NULL, t_min); | |
230 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max); | |
1da177e4 | 231 | |
1f52af0f JD |
232 | static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2); |
233 | static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0); | |
234 | static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1); | |
1da177e4 | 235 | |
5975dfbf | 236 | static struct attribute *lm77_attrs[] = { |
48dbd6ff GR |
237 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
238 | &sensor_dev_attr_temp1_crit.dev_attr.attr, | |
239 | &sensor_dev_attr_temp1_min.dev_attr.attr, | |
240 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
241 | &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, | |
242 | &sensor_dev_attr_temp1_min_hyst.dev_attr.attr, | |
243 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
1f52af0f JD |
244 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
245 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
246 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
247 | NULL |
248 | }; | |
5975dfbf | 249 | ATTRIBUTE_GROUPS(lm77); |
0501a381 | 250 | |
a189dd62 | 251 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
efd2d117 | 252 | static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info) |
1da177e4 | 253 | { |
efd2d117 | 254 | struct i2c_adapter *adapter = client->adapter; |
747d9bed | 255 | int i, cur, conf, hyst, crit, min, max; |
1da177e4 LT |
256 | |
257 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
258 | I2C_FUNC_SMBUS_WORD_DATA)) | |
a189dd62 | 259 | return -ENODEV; |
1da177e4 | 260 | |
02fe2fd9 GR |
261 | /* |
262 | * Here comes the remaining detection. Since the LM77 has no | |
263 | * register dedicated to identification, we have to rely on the | |
264 | * following tricks: | |
265 | * | |
266 | * 1. the high 4 bits represent the sign and thus they should | |
267 | * always be the same | |
268 | * 2. the high 3 bits are unused in the configuration register | |
269 | * 3. addresses 0x06 and 0x07 return the last read value | |
270 | * 4. registers cycling over 8-address boundaries | |
271 | * | |
272 | * Word-sized registers are high-byte first. | |
273 | */ | |
1da177e4 | 274 | |
747d9bed | 275 | /* addresses cycling */ |
efd2d117 GR |
276 | cur = i2c_smbus_read_word_data(client, 0); |
277 | conf = i2c_smbus_read_byte_data(client, 1); | |
278 | hyst = i2c_smbus_read_word_data(client, 2); | |
279 | crit = i2c_smbus_read_word_data(client, 3); | |
280 | min = i2c_smbus_read_word_data(client, 4); | |
281 | max = i2c_smbus_read_word_data(client, 5); | |
747d9bed | 282 | for (i = 8; i <= 0xff; i += 8) { |
efd2d117 GR |
283 | if (i2c_smbus_read_byte_data(client, i + 1) != conf |
284 | || i2c_smbus_read_word_data(client, i + 2) != hyst | |
285 | || i2c_smbus_read_word_data(client, i + 3) != crit | |
286 | || i2c_smbus_read_word_data(client, i + 4) != min | |
287 | || i2c_smbus_read_word_data(client, i + 5) != max) | |
a189dd62 | 288 | return -ENODEV; |
747d9bed | 289 | } |
1da177e4 | 290 | |
747d9bed JD |
291 | /* sign bits */ |
292 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
293 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
294 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
295 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
296 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
297 | return -ENODEV; | |
1da177e4 | 298 | |
747d9bed JD |
299 | /* unused bits */ |
300 | if (conf & 0xe0) | |
301 | return -ENODEV; | |
302 | ||
303 | /* 0x06 and 0x07 return the last read value */ | |
efd2d117 GR |
304 | cur = i2c_smbus_read_word_data(client, 0); |
305 | if (i2c_smbus_read_word_data(client, 6) != cur | |
306 | || i2c_smbus_read_word_data(client, 7) != cur) | |
747d9bed | 307 | return -ENODEV; |
efd2d117 GR |
308 | hyst = i2c_smbus_read_word_data(client, 2); |
309 | if (i2c_smbus_read_word_data(client, 6) != hyst | |
310 | || i2c_smbus_read_word_data(client, 7) != hyst) | |
747d9bed | 311 | return -ENODEV; |
efd2d117 GR |
312 | min = i2c_smbus_read_word_data(client, 4); |
313 | if (i2c_smbus_read_word_data(client, 6) != min | |
314 | || i2c_smbus_read_word_data(client, 7) != min) | |
747d9bed | 315 | return -ENODEV; |
1da177e4 | 316 | |
a189dd62 | 317 | strlcpy(info->type, "lm77", I2C_NAME_SIZE); |
1da177e4 | 318 | |
a189dd62 JD |
319 | return 0; |
320 | } | |
321 | ||
9f9edcd4 GR |
322 | static void lm77_init_client(struct i2c_client *client) |
323 | { | |
324 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
325 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
326 | if (conf & 1) | |
327 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
328 | } | |
329 | ||
efd2d117 | 330 | static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id) |
a189dd62 | 331 | { |
efd2d117 | 332 | struct device *dev = &client->dev; |
5975dfbf | 333 | struct device *hwmon_dev; |
a189dd62 | 334 | struct lm77_data *data; |
a189dd62 | 335 | |
52714c04 GR |
336 | data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL); |
337 | if (!data) | |
338 | return -ENOMEM; | |
1da177e4 | 339 | |
5975dfbf | 340 | data->client = client; |
9a61bf63 | 341 | mutex_init(&data->update_lock); |
1da177e4 | 342 | |
1da177e4 | 343 | /* Initialize the LM77 chip */ |
efd2d117 | 344 | lm77_init_client(client); |
1da177e4 | 345 | |
5975dfbf GR |
346 | hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, |
347 | data, lm77_groups); | |
348 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
1da177e4 LT |
349 | } |
350 | ||
9f9edcd4 GR |
351 | static const struct i2c_device_id lm77_id[] = { |
352 | { "lm77", 0 }, | |
353 | { } | |
354 | }; | |
355 | MODULE_DEVICE_TABLE(i2c, lm77_id); | |
1da177e4 | 356 | |
9f9edcd4 GR |
357 | /* This is the driver that will be inserted */ |
358 | static struct i2c_driver lm77_driver = { | |
359 | .class = I2C_CLASS_HWMON, | |
360 | .driver = { | |
361 | .name = "lm77", | |
362 | }, | |
363 | .probe = lm77_probe, | |
9f9edcd4 GR |
364 | .id_table = lm77_id, |
365 | .detect = lm77_detect, | |
366 | .address_list = normal_i2c, | |
367 | }; | |
1da177e4 | 368 | |
f0967eea | 369 | module_i2c_driver(lm77_driver); |
1da177e4 LT |
370 | |
371 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
372 | MODULE_DESCRIPTION("LM77 driver"); | |
373 | MODULE_LICENSE("GPL"); |