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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 LT |
2 | /* |
3 | * lm92 - Hardware monitoring driver | |
7c81c60f | 4 | * Copyright (C) 2005-2008 Jean Delvare <jdelvare@suse.de> |
1da177e4 LT |
5 | * |
6 | * Based on the lm90 driver, with some ideas taken from the lm_sensors | |
7 | * lm92 driver as well. | |
8 | * | |
9 | * The LM92 is a sensor chip made by National Semiconductor. It reports | |
10 | * its own temperature with a 0.0625 deg resolution and a 0.33 deg | |
11 | * accuracy. Complete datasheet can be obtained from National's website | |
12 | * at: | |
13 | * http://www.national.com/pf/LM/LM92.html | |
14 | * | |
15 | * This driver also supports the MAX6635 sensor chip made by Maxim. | |
16 | * This chip is compatible with the LM92, but has a lesser accuracy | |
17 | * (1.0 deg). Complete datasheet can be obtained from Maxim's website | |
18 | * at: | |
19 | * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074 | |
20 | * | |
21 | * Since the LM92 was the first chipset supported by this driver, most | |
22 | * comments will refer to this chipset, but are actually general and | |
23 | * concern all supported chipsets, unless mentioned otherwise. | |
24 | * | |
25 | * Support could easily be added for the National Semiconductor LM76 | |
26 | * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible | |
27 | * with the LM92. | |
1da177e4 LT |
28 | */ |
29 | ||
30 | #include <linux/module.h> | |
31 | #include <linux/init.h> | |
32 | #include <linux/slab.h> | |
33 | #include <linux/i2c.h> | |
943b0830 | 34 | #include <linux/hwmon.h> |
6cb59e91 | 35 | #include <linux/hwmon-sysfs.h> |
943b0830 | 36 | #include <linux/err.h> |
9a61bf63 | 37 | #include <linux/mutex.h> |
dcd8f392 | 38 | #include <linux/jiffies.h> |
1da177e4 | 39 | |
a318afd8 GR |
40 | /* |
41 | * The LM92 and MAX6635 have 2 two-state pins for address selection, | |
42 | * resulting in 4 possible addresses. | |
43 | */ | |
25e9c86d MH |
44 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
45 | I2C_CLIENT_END }; | |
10ecacd7 | 46 | enum chips { lm92, max6635 }; |
1da177e4 | 47 | |
1da177e4 LT |
48 | /* The LM92 registers */ |
49 | #define LM92_REG_CONFIG 0x01 /* 8-bit, RW */ | |
50 | #define LM92_REG_TEMP 0x00 /* 16-bit, RO */ | |
51 | #define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */ | |
52 | #define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */ | |
53 | #define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */ | |
54 | #define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */ | |
55 | #define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */ | |
56 | ||
a318afd8 GR |
57 | /* |
58 | * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius, | |
59 | * left-justified in 16-bit registers. No rounding is done, with such | |
60 | * a resolution it's just not worth it. Note that the MAX6635 doesn't | |
61 | * make use of the 4 lower bits for limits (i.e. effective resolution | |
62 | * for limits is 1 degree Celsius). | |
63 | */ | |
1da177e4 LT |
64 | static inline int TEMP_FROM_REG(s16 reg) |
65 | { | |
66 | return reg / 8 * 625 / 10; | |
67 | } | |
68 | ||
5b963089 | 69 | static inline s16 TEMP_TO_REG(long val) |
1da177e4 | 70 | { |
5b963089 | 71 | val = clamp_val(val, -60000, 160000); |
1da177e4 LT |
72 | return val * 10 / 625 * 8; |
73 | } | |
74 | ||
75 | /* Alarm flags are stored in the 3 LSB of the temperature register */ | |
76 | static inline u8 ALARMS_FROM_REG(s16 reg) | |
77 | { | |
78 | return reg & 0x0007; | |
79 | } | |
80 | ||
b8fe58e9 GR |
81 | enum temp_index { |
82 | t_input, | |
83 | t_crit, | |
84 | t_min, | |
85 | t_max, | |
86 | t_hyst, | |
87 | t_num_regs | |
88 | }; | |
89 | ||
90 | static const u8 regs[t_num_regs] = { | |
91 | [t_input] = LM92_REG_TEMP, | |
92 | [t_crit] = LM92_REG_TEMP_CRIT, | |
93 | [t_min] = LM92_REG_TEMP_LOW, | |
94 | [t_max] = LM92_REG_TEMP_HIGH, | |
95 | [t_hyst] = LM92_REG_TEMP_HYST, | |
96 | }; | |
97 | ||
1da177e4 LT |
98 | /* Client data (each client gets its own) */ |
99 | struct lm92_data { | |
030004b1 | 100 | struct i2c_client *client; |
9a61bf63 | 101 | struct mutex update_lock; |
952a11ca | 102 | bool valid; /* false until following fields are valid */ |
1da177e4 LT |
103 | unsigned long last_updated; /* in jiffies */ |
104 | ||
105 | /* registers values */ | |
b8fe58e9 | 106 | s16 temp[t_num_regs]; /* index with enum temp_index */ |
1da177e4 LT |
107 | }; |
108 | ||
1da177e4 LT |
109 | /* |
110 | * Sysfs attributes and callback functions | |
111 | */ | |
112 | ||
113 | static struct lm92_data *lm92_update_device(struct device *dev) | |
114 | { | |
030004b1 GR |
115 | struct lm92_data *data = dev_get_drvdata(dev); |
116 | struct i2c_client *client = data->client; | |
b8fe58e9 | 117 | int i; |
1da177e4 | 118 | |
9a61bf63 | 119 | mutex_lock(&data->update_lock); |
1da177e4 | 120 | |
0665a1d6 GR |
121 | if (time_after(jiffies, data->last_updated + HZ) || |
122 | !data->valid) { | |
1da177e4 | 123 | dev_dbg(&client->dev, "Updating lm92 data\n"); |
b8fe58e9 GR |
124 | for (i = 0; i < t_num_regs; i++) { |
125 | data->temp[i] = | |
126 | i2c_smbus_read_word_swapped(client, regs[i]); | |
127 | } | |
1da177e4 | 128 | data->last_updated = jiffies; |
952a11ca | 129 | data->valid = true; |
1da177e4 LT |
130 | } |
131 | ||
9a61bf63 | 132 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
133 | |
134 | return data; | |
135 | } | |
136 | ||
185c993f | 137 | static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, |
b8fe58e9 GR |
138 | char *buf) |
139 | { | |
140 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); | |
141 | struct lm92_data *data = lm92_update_device(dev); | |
142 | ||
143 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])); | |
1da177e4 | 144 | } |
1da177e4 | 145 | |
185c993f GR |
146 | static ssize_t temp_store(struct device *dev, |
147 | struct device_attribute *devattr, const char *buf, | |
148 | size_t count) | |
1da177e4 | 149 | { |
b8fe58e9 | 150 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
030004b1 GR |
151 | struct lm92_data *data = dev_get_drvdata(dev); |
152 | struct i2c_client *client = data->client; | |
b8fe58e9 GR |
153 | int nr = attr->index; |
154 | long val; | |
155 | int err; | |
0665a1d6 | 156 | |
b8fe58e9 GR |
157 | err = kstrtol(buf, 10, &val); |
158 | if (err) | |
159 | return err; | |
160 | ||
161 | mutex_lock(&data->update_lock); | |
162 | data->temp[nr] = TEMP_TO_REG(val); | |
163 | i2c_smbus_write_word_swapped(client, regs[nr], data->temp[nr]); | |
164 | mutex_unlock(&data->update_lock); | |
165 | return count; | |
1da177e4 | 166 | } |
b8fe58e9 | 167 | |
185c993f | 168 | static ssize_t temp_hyst_show(struct device *dev, |
b8fe58e9 | 169 | struct device_attribute *devattr, char *buf) |
1da177e4 | 170 | { |
b8fe58e9 | 171 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
1da177e4 | 172 | struct lm92_data *data = lm92_update_device(dev); |
0665a1d6 | 173 | |
b8fe58e9 GR |
174 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]) |
175 | - TEMP_FROM_REG(data->temp[t_hyst])); | |
1da177e4 | 176 | } |
b8fe58e9 | 177 | |
3dba95df JL |
178 | static ssize_t temp1_min_hyst_show(struct device *dev, |
179 | struct device_attribute *attr, char *buf) | |
1da177e4 LT |
180 | { |
181 | struct lm92_data *data = lm92_update_device(dev); | |
0665a1d6 | 182 | |
b8fe58e9 GR |
183 | return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[t_min]) |
184 | + TEMP_FROM_REG(data->temp[t_hyst])); | |
1da177e4 LT |
185 | } |
186 | ||
185c993f GR |
187 | static ssize_t temp_hyst_store(struct device *dev, |
188 | struct device_attribute *devattr, | |
189 | const char *buf, size_t count) | |
1da177e4 | 190 | { |
b8fe58e9 | 191 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
030004b1 GR |
192 | struct lm92_data *data = dev_get_drvdata(dev); |
193 | struct i2c_client *client = data->client; | |
a318afd8 GR |
194 | long val; |
195 | int err; | |
196 | ||
197 | err = kstrtol(buf, 10, &val); | |
198 | if (err) | |
199 | return err; | |
1da177e4 | 200 | |
5b963089 | 201 | val = clamp_val(val, -120000, 220000); |
9a61bf63 | 202 | mutex_lock(&data->update_lock); |
0665a1d6 | 203 | data->temp[t_hyst] = |
5b963089 | 204 | TEMP_TO_REG(TEMP_FROM_REG(data->temp[attr->index]) - val); |
90f4102c | 205 | i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST, |
5b963089 | 206 | data->temp[t_hyst]); |
9a61bf63 | 207 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
208 | return count; |
209 | } | |
210 | ||
3dba95df | 211 | static ssize_t alarms_show(struct device *dev, struct device_attribute *attr, |
a318afd8 | 212 | char *buf) |
1da177e4 LT |
213 | { |
214 | struct lm92_data *data = lm92_update_device(dev); | |
0665a1d6 | 215 | |
b8fe58e9 | 216 | return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp[t_input])); |
1da177e4 LT |
217 | } |
218 | ||
185c993f | 219 | static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, |
6cb59e91 JD |
220 | char *buf) |
221 | { | |
222 | int bitnr = to_sensor_dev_attr(attr)->index; | |
223 | struct lm92_data *data = lm92_update_device(dev); | |
b8fe58e9 | 224 | return sprintf(buf, "%d\n", (data->temp[t_input] >> bitnr) & 1); |
6cb59e91 JD |
225 | } |
226 | ||
185c993f GR |
227 | static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input); |
228 | static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, t_crit); | |
229 | static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit); | |
230 | static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, t_min); | |
3dba95df | 231 | static DEVICE_ATTR_RO(temp1_min_hyst); |
185c993f GR |
232 | static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max); |
233 | static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max); | |
3dba95df | 234 | static DEVICE_ATTR_RO(alarms); |
185c993f GR |
235 | static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 2); |
236 | static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 0); | |
237 | static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 1); | |
1da177e4 | 238 | |
1da177e4 LT |
239 | /* |
240 | * Detection and registration | |
241 | */ | |
242 | ||
243 | static void lm92_init_client(struct i2c_client *client) | |
244 | { | |
245 | u8 config; | |
246 | ||
247 | /* Start the conversions if needed */ | |
248 | config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG); | |
249 | if (config & 0x01) | |
250 | i2c_smbus_write_byte_data(client, LM92_REG_CONFIG, | |
251 | config & 0xFE); | |
252 | } | |
253 | ||
030004b1 | 254 | static struct attribute *lm92_attrs[] = { |
b8fe58e9 GR |
255 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
256 | &sensor_dev_attr_temp1_crit.dev_attr.attr, | |
257 | &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, | |
258 | &sensor_dev_attr_temp1_min.dev_attr.attr, | |
0501a381 | 259 | &dev_attr_temp1_min_hyst.attr, |
b8fe58e9 GR |
260 | &sensor_dev_attr_temp1_max.dev_attr.attr, |
261 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
0501a381 | 262 | &dev_attr_alarms.attr, |
6cb59e91 JD |
263 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
264 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
265 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
266 | NULL |
267 | }; | |
030004b1 | 268 | ATTRIBUTE_GROUPS(lm92); |
0501a381 | 269 | |
910e8dcf | 270 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
310ec792 | 271 | static int lm92_detect(struct i2c_client *new_client, |
910e8dcf | 272 | struct i2c_board_info *info) |
1da177e4 | 273 | { |
910e8dcf | 274 | struct i2c_adapter *adapter = new_client->adapter; |
52df6440 JD |
275 | u8 config; |
276 | u16 man_id; | |
1da177e4 LT |
277 | |
278 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
279 | | I2C_FUNC_SMBUS_WORD_DATA)) | |
910e8dcf | 280 | return -ENODEV; |
1da177e4 | 281 | |
52df6440 JD |
282 | config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG); |
283 | man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID); | |
284 | ||
285 | if ((config & 0xe0) == 0x00 && man_id == 0x0180) | |
286 | pr_info("lm92: Found National Semiconductor LM92 chip\n"); | |
52df6440 JD |
287 | else |
288 | return -ENODEV; | |
1da177e4 | 289 | |
f2f394db | 290 | strscpy(info->type, "lm92", I2C_NAME_SIZE); |
910e8dcf JD |
291 | |
292 | return 0; | |
293 | } | |
294 | ||
67487038 | 295 | static int lm92_probe(struct i2c_client *new_client) |
910e8dcf | 296 | { |
030004b1 | 297 | struct device *hwmon_dev; |
910e8dcf | 298 | struct lm92_data *data; |
910e8dcf | 299 | |
705375cc GR |
300 | data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data), |
301 | GFP_KERNEL); | |
302 | if (!data) | |
303 | return -ENOMEM; | |
910e8dcf | 304 | |
030004b1 | 305 | data->client = new_client; |
9a61bf63 | 306 | mutex_init(&data->update_lock); |
1da177e4 | 307 | |
1da177e4 LT |
308 | /* Initialize the chipset */ |
309 | lm92_init_client(new_client); | |
310 | ||
030004b1 GR |
311 | hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev, |
312 | new_client->name, | |
313 | data, lm92_groups); | |
314 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
1da177e4 LT |
315 | } |
316 | ||
1da177e4 LT |
317 | /* |
318 | * Module and driver stuff | |
319 | */ | |
320 | ||
910e8dcf | 321 | static const struct i2c_device_id lm92_id[] = { |
10ecacd7 A |
322 | { "lm92", lm92 }, |
323 | { "max6635", max6635 }, | |
910e8dcf JD |
324 | { } |
325 | }; | |
326 | MODULE_DEVICE_TABLE(i2c, lm92_id); | |
327 | ||
1da177e4 | 328 | static struct i2c_driver lm92_driver = { |
910e8dcf | 329 | .class = I2C_CLASS_HWMON, |
cdaf7934 | 330 | .driver = { |
cdaf7934 LR |
331 | .name = "lm92", |
332 | }, | |
1975d167 | 333 | .probe = lm92_probe, |
910e8dcf JD |
334 | .id_table = lm92_id, |
335 | .detect = lm92_detect, | |
c3813d6a | 336 | .address_list = normal_i2c, |
1da177e4 LT |
337 | }; |
338 | ||
f0967eea | 339 | module_i2c_driver(lm92_driver); |
1da177e4 | 340 | |
7c81c60f | 341 | MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>"); |
1da177e4 LT |
342 | MODULE_DESCRIPTION("LM92/MAX6635 driver"); |
343 | MODULE_LICENSE("GPL"); |