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c942fddf | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
1da177e4 | 2 | /* |
02fe2fd9 GR |
3 | * lm77.c - Part of lm_sensors, Linux kernel modules for hardware |
4 | * monitoring | |
5 | * | |
6 | * Copyright (c) 2004 Andras BALI <drewie@freemail.hu> | |
7 | * | |
8 | * Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77 | |
9 | * is a temperature sensor and thermal window comparator with 0.5 deg | |
10 | * resolution made by National Semiconductor. Complete datasheet can be | |
11 | * obtained at their site: | |
12 | * http://www.national.com/pf/LM/LM77.html | |
02fe2fd9 | 13 | */ |
1da177e4 | 14 | |
1da177e4 LT |
15 | #include <linux/module.h> |
16 | #include <linux/init.h> | |
17 | #include <linux/slab.h> | |
18 | #include <linux/jiffies.h> | |
19 | #include <linux/i2c.h> | |
943b0830 | 20 | #include <linux/hwmon.h> |
1f52af0f | 21 | #include <linux/hwmon-sysfs.h> |
943b0830 | 22 | #include <linux/err.h> |
9a61bf63 | 23 | #include <linux/mutex.h> |
1da177e4 LT |
24 | |
25 | /* Addresses to scan */ | |
25e9c86d MH |
26 | static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, |
27 | I2C_CLIENT_END }; | |
1da177e4 | 28 | |
1da177e4 LT |
29 | /* The LM77 registers */ |
30 | #define LM77_REG_TEMP 0x00 | |
31 | #define LM77_REG_CONF 0x01 | |
32 | #define LM77_REG_TEMP_HYST 0x02 | |
33 | #define LM77_REG_TEMP_CRIT 0x03 | |
34 | #define LM77_REG_TEMP_MIN 0x04 | |
35 | #define LM77_REG_TEMP_MAX 0x05 | |
36 | ||
48dbd6ff GR |
37 | enum temp_index { |
38 | t_input = 0, | |
39 | t_crit, | |
40 | t_min, | |
41 | t_max, | |
42 | t_hyst, | |
43 | t_num_temp | |
44 | }; | |
45 | ||
46 | static const u8 temp_regs[t_num_temp] = { | |
47 | [t_input] = LM77_REG_TEMP, | |
48 | [t_min] = LM77_REG_TEMP_MIN, | |
49 | [t_max] = LM77_REG_TEMP_MAX, | |
50 | [t_crit] = LM77_REG_TEMP_CRIT, | |
51 | [t_hyst] = LM77_REG_TEMP_HYST, | |
52 | }; | |
53 | ||
1da177e4 LT |
54 | /* Each client has this additional data */ |
55 | struct lm77_data { | |
5975dfbf | 56 | struct i2c_client *client; |
9a61bf63 | 57 | struct mutex update_lock; |
1da177e4 LT |
58 | char valid; |
59 | unsigned long last_updated; /* In jiffies */ | |
48dbd6ff | 60 | int temp[t_num_temp]; /* index using temp_index */ |
1da177e4 LT |
61 | u8 alarms; |
62 | }; | |
63 | ||
1da177e4 LT |
64 | /* straight from the datasheet */ |
65 | #define LM77_TEMP_MIN (-55000) | |
66 | #define LM77_TEMP_MAX 125000 | |
67 | ||
02fe2fd9 GR |
68 | /* |
69 | * In the temperature registers, the low 3 bits are not part of the | |
70 | * temperature values; they are the status bits. | |
71 | */ | |
413b6451 | 72 | static inline s16 LM77_TEMP_TO_REG(int temp) |
1da177e4 | 73 | { |
99765db2 | 74 | return (temp / 500) * 8; |
1da177e4 LT |
75 | } |
76 | ||
413b6451 | 77 | static inline int LM77_TEMP_FROM_REG(s16 reg) |
1da177e4 | 78 | { |
413b6451 | 79 | return (reg / 8) * 500; |
1da177e4 LT |
80 | } |
81 | ||
9f9edcd4 GR |
82 | /* |
83 | * All registers are word-sized, except for the configuration register. | |
84 | * The LM77 uses the high-byte first convention. | |
85 | */ | |
86 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
87 | { | |
88 | if (reg == LM77_REG_CONF) | |
89 | return i2c_smbus_read_byte_data(client, reg); | |
90 | else | |
91 | return i2c_smbus_read_word_swapped(client, reg); | |
92 | } | |
93 | ||
94 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
95 | { | |
96 | if (reg == LM77_REG_CONF) | |
97 | return i2c_smbus_write_byte_data(client, reg, value); | |
98 | else | |
99 | return i2c_smbus_write_word_swapped(client, reg, value); | |
100 | } | |
101 | ||
102 | static struct lm77_data *lm77_update_device(struct device *dev) | |
103 | { | |
5975dfbf GR |
104 | struct lm77_data *data = dev_get_drvdata(dev); |
105 | struct i2c_client *client = data->client; | |
48dbd6ff | 106 | int i; |
9f9edcd4 GR |
107 | |
108 | mutex_lock(&data->update_lock); | |
109 | ||
110 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
111 | || !data->valid) { | |
112 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
48dbd6ff GR |
113 | for (i = 0; i < t_num_temp; i++) { |
114 | data->temp[i] = | |
115 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
116 | temp_regs[i])); | |
117 | } | |
9f9edcd4 GR |
118 | data->alarms = |
119 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
120 | data->last_updated = jiffies; | |
121 | data->valid = 1; | |
122 | } | |
123 | ||
124 | mutex_unlock(&data->update_lock); | |
125 | ||
126 | return data; | |
127 | } | |
128 | ||
1da177e4 LT |
129 | /* sysfs stuff */ |
130 | ||
97b539d5 | 131 | static ssize_t temp_show(struct device *dev, struct device_attribute *devattr, |
48dbd6ff | 132 | char *buf) |
1da177e4 | 133 | { |
48dbd6ff | 134 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
1da177e4 | 135 | struct lm77_data *data = lm77_update_device(dev); |
48dbd6ff GR |
136 | |
137 | return sprintf(buf, "%d\n", data->temp[attr->index]); | |
1da177e4 | 138 | } |
48dbd6ff | 139 | |
97b539d5 | 140 | static ssize_t temp_hyst_show(struct device *dev, |
48dbd6ff | 141 | struct device_attribute *devattr, 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 | int nr = attr->index; |
146 | int temp; | |
1da177e4 | 147 | |
48dbd6ff GR |
148 | temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] : |
149 | data->temp[nr] - data->temp[t_hyst]; | |
1da177e4 | 150 | |
48dbd6ff GR |
151 | return sprintf(buf, "%d\n", temp); |
152 | } | |
1da177e4 | 153 | |
97b539d5 GR |
154 | static ssize_t temp_store(struct device *dev, |
155 | struct device_attribute *devattr, const char *buf, | |
156 | size_t count) | |
1da177e4 | 157 | { |
48dbd6ff | 158 | struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); |
5975dfbf GR |
159 | struct lm77_data *data = dev_get_drvdata(dev); |
160 | struct i2c_client *client = data->client; | |
48dbd6ff GR |
161 | int nr = attr->index; |
162 | long val; | |
02fe2fd9 GR |
163 | int err; |
164 | ||
48dbd6ff | 165 | err = kstrtol(buf, 10, &val); |
02fe2fd9 GR |
166 | if (err) |
167 | return err; | |
1da177e4 | 168 | |
99765db2 | 169 | val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX); |
9a61bf63 | 170 | mutex_lock(&data->update_lock); |
48dbd6ff GR |
171 | data->temp[nr] = val; |
172 | lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val)); | |
9a61bf63 | 173 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
174 | return count; |
175 | } | |
176 | ||
48dbd6ff GR |
177 | /* |
178 | * hysteresis is stored as a relative value on the chip, so it has to be | |
179 | * converted first. | |
180 | */ | |
97b539d5 GR |
181 | static ssize_t temp_hyst_store(struct device *dev, |
182 | struct device_attribute *devattr, | |
183 | const char *buf, size_t count) | |
1da177e4 | 184 | { |
5975dfbf GR |
185 | struct lm77_data *data = dev_get_drvdata(dev); |
186 | struct i2c_client *client = data->client; | |
99765db2 | 187 | long val; |
02fe2fd9 GR |
188 | int err; |
189 | ||
99765db2 | 190 | err = kstrtol(buf, 10, &val); |
02fe2fd9 GR |
191 | if (err) |
192 | return err; | |
193 | ||
9a61bf63 | 194 | mutex_lock(&data->update_lock); |
99765db2 AL |
195 | val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX); |
196 | data->temp[t_hyst] = val; | |
48dbd6ff GR |
197 | lm77_write_value(client, LM77_REG_TEMP_HYST, |
198 | LM77_TEMP_TO_REG(data->temp[t_hyst])); | |
9a61bf63 | 199 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
200 | return count; |
201 | } | |
202 | ||
97b539d5 | 203 | static ssize_t alarm_show(struct device *dev, struct device_attribute *attr, |
1f52af0f JD |
204 | char *buf) |
205 | { | |
206 | int bitnr = to_sensor_dev_attr(attr)->index; | |
207 | struct lm77_data *data = lm77_update_device(dev); | |
208 | return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1); | |
209 | } | |
210 | ||
97b539d5 GR |
211 | static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input); |
212 | static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, t_crit); | |
213 | static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, t_min); | |
214 | static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max); | |
215 | ||
216 | static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit); | |
217 | static SENSOR_DEVICE_ATTR_RO(temp1_min_hyst, temp_hyst, t_min); | |
218 | static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max); | |
219 | ||
220 | static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 2); | |
221 | static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 0); | |
222 | static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 1); | |
1da177e4 | 223 | |
5975dfbf | 224 | static struct attribute *lm77_attrs[] = { |
48dbd6ff GR |
225 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
226 | &sensor_dev_attr_temp1_crit.dev_attr.attr, | |
227 | &sensor_dev_attr_temp1_min.dev_attr.attr, | |
228 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
229 | &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr, | |
230 | &sensor_dev_attr_temp1_min_hyst.dev_attr.attr, | |
231 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
1f52af0f JD |
232 | &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr, |
233 | &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, | |
234 | &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, | |
0501a381 MH |
235 | NULL |
236 | }; | |
5975dfbf | 237 | ATTRIBUTE_GROUPS(lm77); |
0501a381 | 238 | |
a189dd62 | 239 | /* Return 0 if detection is successful, -ENODEV otherwise */ |
efd2d117 | 240 | static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info) |
1da177e4 | 241 | { |
efd2d117 | 242 | struct i2c_adapter *adapter = client->adapter; |
747d9bed | 243 | int i, cur, conf, hyst, crit, min, max; |
1da177e4 LT |
244 | |
245 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
246 | I2C_FUNC_SMBUS_WORD_DATA)) | |
a189dd62 | 247 | return -ENODEV; |
1da177e4 | 248 | |
02fe2fd9 GR |
249 | /* |
250 | * Here comes the remaining detection. Since the LM77 has no | |
251 | * register dedicated to identification, we have to rely on the | |
252 | * following tricks: | |
253 | * | |
254 | * 1. the high 4 bits represent the sign and thus they should | |
255 | * always be the same | |
256 | * 2. the high 3 bits are unused in the configuration register | |
257 | * 3. addresses 0x06 and 0x07 return the last read value | |
258 | * 4. registers cycling over 8-address boundaries | |
259 | * | |
260 | * Word-sized registers are high-byte first. | |
261 | */ | |
1da177e4 | 262 | |
747d9bed | 263 | /* addresses cycling */ |
efd2d117 GR |
264 | cur = i2c_smbus_read_word_data(client, 0); |
265 | conf = i2c_smbus_read_byte_data(client, 1); | |
266 | hyst = i2c_smbus_read_word_data(client, 2); | |
267 | crit = i2c_smbus_read_word_data(client, 3); | |
268 | min = i2c_smbus_read_word_data(client, 4); | |
269 | max = i2c_smbus_read_word_data(client, 5); | |
747d9bed | 270 | for (i = 8; i <= 0xff; i += 8) { |
efd2d117 GR |
271 | if (i2c_smbus_read_byte_data(client, i + 1) != conf |
272 | || i2c_smbus_read_word_data(client, i + 2) != hyst | |
273 | || i2c_smbus_read_word_data(client, i + 3) != crit | |
274 | || i2c_smbus_read_word_data(client, i + 4) != min | |
275 | || i2c_smbus_read_word_data(client, i + 5) != max) | |
a189dd62 | 276 | return -ENODEV; |
747d9bed | 277 | } |
1da177e4 | 278 | |
747d9bed JD |
279 | /* sign bits */ |
280 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
281 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
282 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
283 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
284 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
285 | return -ENODEV; | |
1da177e4 | 286 | |
747d9bed JD |
287 | /* unused bits */ |
288 | if (conf & 0xe0) | |
289 | return -ENODEV; | |
290 | ||
291 | /* 0x06 and 0x07 return the last read value */ | |
efd2d117 GR |
292 | cur = i2c_smbus_read_word_data(client, 0); |
293 | if (i2c_smbus_read_word_data(client, 6) != cur | |
294 | || i2c_smbus_read_word_data(client, 7) != cur) | |
747d9bed | 295 | return -ENODEV; |
efd2d117 GR |
296 | hyst = i2c_smbus_read_word_data(client, 2); |
297 | if (i2c_smbus_read_word_data(client, 6) != hyst | |
298 | || i2c_smbus_read_word_data(client, 7) != hyst) | |
747d9bed | 299 | return -ENODEV; |
efd2d117 GR |
300 | min = i2c_smbus_read_word_data(client, 4); |
301 | if (i2c_smbus_read_word_data(client, 6) != min | |
302 | || i2c_smbus_read_word_data(client, 7) != min) | |
747d9bed | 303 | return -ENODEV; |
1da177e4 | 304 | |
a189dd62 | 305 | strlcpy(info->type, "lm77", I2C_NAME_SIZE); |
1da177e4 | 306 | |
a189dd62 JD |
307 | return 0; |
308 | } | |
309 | ||
9f9edcd4 GR |
310 | static void lm77_init_client(struct i2c_client *client) |
311 | { | |
312 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
313 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
314 | if (conf & 1) | |
315 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
316 | } | |
317 | ||
67487038 | 318 | static int lm77_probe(struct i2c_client *client) |
a189dd62 | 319 | { |
efd2d117 | 320 | struct device *dev = &client->dev; |
5975dfbf | 321 | struct device *hwmon_dev; |
a189dd62 | 322 | struct lm77_data *data; |
a189dd62 | 323 | |
52714c04 GR |
324 | data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL); |
325 | if (!data) | |
326 | return -ENOMEM; | |
1da177e4 | 327 | |
5975dfbf | 328 | data->client = client; |
9a61bf63 | 329 | mutex_init(&data->update_lock); |
1da177e4 | 330 | |
1da177e4 | 331 | /* Initialize the LM77 chip */ |
efd2d117 | 332 | lm77_init_client(client); |
1da177e4 | 333 | |
5975dfbf GR |
334 | hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name, |
335 | data, lm77_groups); | |
336 | return PTR_ERR_OR_ZERO(hwmon_dev); | |
1da177e4 LT |
337 | } |
338 | ||
9f9edcd4 GR |
339 | static const struct i2c_device_id lm77_id[] = { |
340 | { "lm77", 0 }, | |
341 | { } | |
342 | }; | |
343 | MODULE_DEVICE_TABLE(i2c, lm77_id); | |
1da177e4 | 344 | |
9f9edcd4 GR |
345 | /* This is the driver that will be inserted */ |
346 | static struct i2c_driver lm77_driver = { | |
347 | .class = I2C_CLASS_HWMON, | |
348 | .driver = { | |
349 | .name = "lm77", | |
350 | }, | |
67487038 | 351 | .probe_new = lm77_probe, |
9f9edcd4 GR |
352 | .id_table = lm77_id, |
353 | .detect = lm77_detect, | |
354 | .address_list = normal_i2c, | |
355 | }; | |
1da177e4 | 356 | |
f0967eea | 357 | module_i2c_driver(lm77_driver); |
1da177e4 LT |
358 | |
359 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
360 | MODULE_DESCRIPTION("LM77 driver"); | |
361 | MODULE_LICENSE("GPL"); |