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1da177e4 LT |
1 | /* |
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 | */ | |
27 | ||
28 | #include <linux/config.h> | |
29 | #include <linux/module.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/slab.h> | |
32 | #include <linux/jiffies.h> | |
33 | #include <linux/i2c.h> | |
34 | #include <linux/i2c-sensor.h> | |
35 | ||
36 | ||
37 | /* Addresses to scan */ | |
38 | static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END }; | |
39 | static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END }; | |
40 | ||
41 | /* Insmod parameters */ | |
42 | SENSORS_INSMOD_1(lm77); | |
43 | ||
44 | /* The LM77 registers */ | |
45 | #define LM77_REG_TEMP 0x00 | |
46 | #define LM77_REG_CONF 0x01 | |
47 | #define LM77_REG_TEMP_HYST 0x02 | |
48 | #define LM77_REG_TEMP_CRIT 0x03 | |
49 | #define LM77_REG_TEMP_MIN 0x04 | |
50 | #define LM77_REG_TEMP_MAX 0x05 | |
51 | ||
52 | /* Each client has this additional data */ | |
53 | struct lm77_data { | |
54 | struct i2c_client client; | |
55 | struct semaphore update_lock; | |
56 | char valid; | |
57 | unsigned long last_updated; /* In jiffies */ | |
58 | int temp_input; /* Temperatures */ | |
59 | int temp_crit; | |
60 | int temp_min; | |
61 | int temp_max; | |
62 | int temp_hyst; | |
63 | u8 alarms; | |
64 | }; | |
65 | ||
66 | static int lm77_attach_adapter(struct i2c_adapter *adapter); | |
67 | static int lm77_detect(struct i2c_adapter *adapter, int address, int kind); | |
68 | static void lm77_init_client(struct i2c_client *client); | |
69 | static int lm77_detach_client(struct i2c_client *client); | |
70 | static u16 lm77_read_value(struct i2c_client *client, u8 reg); | |
71 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value); | |
72 | ||
73 | static struct lm77_data *lm77_update_device(struct device *dev); | |
74 | ||
75 | ||
76 | /* This is the driver that will be inserted */ | |
77 | static struct i2c_driver lm77_driver = { | |
78 | .owner = THIS_MODULE, | |
79 | .name = "lm77", | |
80 | .flags = I2C_DF_NOTIFY, | |
81 | .attach_adapter = lm77_attach_adapter, | |
82 | .detach_client = lm77_detach_client, | |
83 | }; | |
84 | ||
85 | /* straight from the datasheet */ | |
86 | #define LM77_TEMP_MIN (-55000) | |
87 | #define LM77_TEMP_MAX 125000 | |
88 | ||
89 | /* In the temperature registers, the low 3 bits are not part of the | |
90 | temperature values; they are the status bits. */ | |
91 | static inline u16 LM77_TEMP_TO_REG(int temp) | |
92 | { | |
93 | int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX); | |
94 | return (u16)((ntemp / 500) * 8); | |
95 | } | |
96 | ||
97 | static inline int LM77_TEMP_FROM_REG(u16 reg) | |
98 | { | |
99 | return ((int)reg / 8) * 500; | |
100 | } | |
101 | ||
102 | /* sysfs stuff */ | |
103 | ||
104 | /* read routines for temperature limits */ | |
105 | #define show(value) \ | |
106 | static ssize_t show_##value(struct device *dev, char *buf) \ | |
107 | { \ | |
108 | struct lm77_data *data = lm77_update_device(dev); \ | |
109 | return sprintf(buf, "%d\n", data->value); \ | |
110 | } | |
111 | ||
112 | show(temp_input); | |
113 | show(temp_crit); | |
114 | show(temp_min); | |
115 | show(temp_max); | |
116 | show(alarms); | |
117 | ||
118 | /* read routines for hysteresis values */ | |
119 | static ssize_t show_temp_crit_hyst(struct device *dev, char *buf) | |
120 | { | |
121 | struct lm77_data *data = lm77_update_device(dev); | |
122 | return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst); | |
123 | } | |
124 | static ssize_t show_temp_min_hyst(struct device *dev, char *buf) | |
125 | { | |
126 | struct lm77_data *data = lm77_update_device(dev); | |
127 | return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst); | |
128 | } | |
129 | static ssize_t show_temp_max_hyst(struct device *dev, char *buf) | |
130 | { | |
131 | struct lm77_data *data = lm77_update_device(dev); | |
132 | return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst); | |
133 | } | |
134 | ||
135 | /* write routines */ | |
136 | #define set(value, reg) \ | |
137 | static ssize_t set_##value(struct device *dev, const char *buf, size_t count) \ | |
138 | { \ | |
139 | struct i2c_client *client = to_i2c_client(dev); \ | |
140 | struct lm77_data *data = i2c_get_clientdata(client); \ | |
141 | long val = simple_strtoul(buf, NULL, 10); \ | |
142 | \ | |
143 | down(&data->update_lock); \ | |
144 | data->value = val; \ | |
145 | lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \ | |
146 | up(&data->update_lock); \ | |
147 | return count; \ | |
148 | } | |
149 | ||
150 | set(temp_min, LM77_REG_TEMP_MIN); | |
151 | set(temp_max, LM77_REG_TEMP_MAX); | |
152 | ||
153 | /* hysteresis is stored as a relative value on the chip, so it has to be | |
154 | converted first */ | |
155 | static ssize_t set_temp_crit_hyst(struct device *dev, const char *buf, size_t count) | |
156 | { | |
157 | struct i2c_client *client = to_i2c_client(dev); | |
158 | struct lm77_data *data = i2c_get_clientdata(client); | |
159 | unsigned long val = simple_strtoul(buf, NULL, 10); | |
160 | ||
161 | down(&data->update_lock); | |
162 | data->temp_hyst = data->temp_crit - val; | |
163 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
164 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
165 | up(&data->update_lock); | |
166 | return count; | |
167 | } | |
168 | ||
169 | /* preserve hysteresis when setting T_crit */ | |
170 | static ssize_t set_temp_crit(struct device *dev, const char *buf, size_t count) | |
171 | { | |
172 | struct i2c_client *client = to_i2c_client(dev); | |
173 | struct lm77_data *data = i2c_get_clientdata(client); | |
174 | long val = simple_strtoul(buf, NULL, 10); | |
175 | int oldcrithyst; | |
176 | ||
177 | down(&data->update_lock); | |
178 | oldcrithyst = data->temp_crit - data->temp_hyst; | |
179 | data->temp_crit = val; | |
180 | data->temp_hyst = data->temp_crit - oldcrithyst; | |
181 | lm77_write_value(client, LM77_REG_TEMP_CRIT, | |
182 | LM77_TEMP_TO_REG(data->temp_crit)); | |
183 | lm77_write_value(client, LM77_REG_TEMP_HYST, | |
184 | LM77_TEMP_TO_REG(data->temp_hyst)); | |
185 | up(&data->update_lock); | |
186 | return count; | |
187 | } | |
188 | ||
189 | static DEVICE_ATTR(temp1_input, S_IRUGO, | |
190 | show_temp_input, NULL); | |
191 | static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, | |
192 | show_temp_crit, set_temp_crit); | |
193 | static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, | |
194 | show_temp_min, set_temp_min); | |
195 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, | |
196 | show_temp_max, set_temp_max); | |
197 | ||
198 | static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, | |
199 | show_temp_crit_hyst, set_temp_crit_hyst); | |
200 | static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, | |
201 | show_temp_min_hyst, NULL); | |
202 | static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, | |
203 | show_temp_max_hyst, NULL); | |
204 | ||
205 | static DEVICE_ATTR(alarms, S_IRUGO, | |
206 | show_alarms, NULL); | |
207 | ||
208 | static int lm77_attach_adapter(struct i2c_adapter *adapter) | |
209 | { | |
210 | if (!(adapter->class & I2C_CLASS_HWMON)) | |
211 | return 0; | |
212 | return i2c_detect(adapter, &addr_data, lm77_detect); | |
213 | } | |
214 | ||
215 | /* This function is called by i2c_detect */ | |
216 | static int lm77_detect(struct i2c_adapter *adapter, int address, int kind) | |
217 | { | |
218 | struct i2c_client *new_client; | |
219 | struct lm77_data *data; | |
220 | int err = 0; | |
221 | const char *name = ""; | |
222 | ||
223 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
224 | I2C_FUNC_SMBUS_WORD_DATA)) | |
225 | goto exit; | |
226 | ||
227 | /* OK. For now, we presume we have a valid client. We now create the | |
228 | client structure, even though we cannot fill it completely yet. | |
229 | But it allows us to access lm77_{read,write}_value. */ | |
230 | if (!(data = kmalloc(sizeof(struct lm77_data), GFP_KERNEL))) { | |
231 | err = -ENOMEM; | |
232 | goto exit; | |
233 | } | |
234 | memset(data, 0, sizeof(struct lm77_data)); | |
235 | ||
236 | new_client = &data->client; | |
237 | i2c_set_clientdata(new_client, data); | |
238 | new_client->addr = address; | |
239 | new_client->adapter = adapter; | |
240 | new_client->driver = &lm77_driver; | |
241 | new_client->flags = 0; | |
242 | ||
243 | /* Here comes the remaining detection. Since the LM77 has no | |
244 | register dedicated to identification, we have to rely on the | |
245 | following tricks: | |
246 | ||
247 | 1. the high 4 bits represent the sign and thus they should | |
248 | always be the same | |
249 | 2. the high 3 bits are unused in the configuration register | |
250 | 3. addresses 0x06 and 0x07 return the last read value | |
251 | 4. registers cycling over 8-address boundaries | |
252 | ||
253 | Word-sized registers are high-byte first. */ | |
254 | if (kind < 0) { | |
255 | int i, cur, conf, hyst, crit, min, max; | |
256 | ||
257 | /* addresses cycling */ | |
258 | cur = i2c_smbus_read_word_data(new_client, 0); | |
259 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
260 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
261 | crit = i2c_smbus_read_word_data(new_client, 3); | |
262 | min = i2c_smbus_read_word_data(new_client, 4); | |
263 | max = i2c_smbus_read_word_data(new_client, 5); | |
264 | for (i = 8; i <= 0xff; i += 8) | |
265 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
266 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
267 | || i2c_smbus_read_word_data(new_client, i + 3) != crit | |
268 | || i2c_smbus_read_word_data(new_client, i + 4) != min | |
269 | || i2c_smbus_read_word_data(new_client, i + 5) != max) | |
270 | goto exit_free; | |
271 | ||
272 | /* sign bits */ | |
273 | if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0) | |
274 | || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0) | |
275 | || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0) | |
276 | || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0) | |
277 | || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0)) | |
278 | goto exit_free; | |
279 | ||
280 | /* unused bits */ | |
281 | if (conf & 0xe0) | |
282 | goto exit_free; | |
283 | ||
284 | /* 0x06 and 0x07 return the last read value */ | |
285 | cur = i2c_smbus_read_word_data(new_client, 0); | |
286 | if (i2c_smbus_read_word_data(new_client, 6) != cur | |
287 | || i2c_smbus_read_word_data(new_client, 7) != cur) | |
288 | goto exit_free; | |
289 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
290 | if (i2c_smbus_read_word_data(new_client, 6) != hyst | |
291 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
292 | goto exit_free; | |
293 | min = i2c_smbus_read_word_data(new_client, 4); | |
294 | if (i2c_smbus_read_word_data(new_client, 6) != min | |
295 | || i2c_smbus_read_word_data(new_client, 7) != min) | |
296 | goto exit_free; | |
297 | ||
298 | } | |
299 | ||
300 | /* Determine the chip type - only one kind supported! */ | |
301 | if (kind <= 0) | |
302 | kind = lm77; | |
303 | ||
304 | if (kind == lm77) { | |
305 | name = "lm77"; | |
306 | } | |
307 | ||
308 | /* Fill in the remaining client fields and put it into the global list */ | |
309 | strlcpy(new_client->name, name, I2C_NAME_SIZE); | |
310 | data->valid = 0; | |
311 | init_MUTEX(&data->update_lock); | |
312 | ||
313 | /* Tell the I2C layer a new client has arrived */ | |
314 | if ((err = i2c_attach_client(new_client))) | |
315 | goto exit_free; | |
316 | ||
317 | /* Initialize the LM77 chip */ | |
318 | lm77_init_client(new_client); | |
319 | ||
320 | /* Register sysfs hooks */ | |
321 | device_create_file(&new_client->dev, &dev_attr_temp1_input); | |
322 | device_create_file(&new_client->dev, &dev_attr_temp1_crit); | |
323 | device_create_file(&new_client->dev, &dev_attr_temp1_min); | |
324 | device_create_file(&new_client->dev, &dev_attr_temp1_max); | |
325 | device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst); | |
326 | device_create_file(&new_client->dev, &dev_attr_temp1_min_hyst); | |
327 | device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst); | |
328 | device_create_file(&new_client->dev, &dev_attr_alarms); | |
329 | return 0; | |
330 | ||
331 | exit_free: | |
332 | kfree(data); | |
333 | exit: | |
334 | return err; | |
335 | } | |
336 | ||
337 | static int lm77_detach_client(struct i2c_client *client) | |
338 | { | |
339 | i2c_detach_client(client); | |
340 | kfree(i2c_get_clientdata(client)); | |
341 | return 0; | |
342 | } | |
343 | ||
344 | /* All registers are word-sized, except for the configuration register. | |
345 | The LM77 uses the high-byte first convention. */ | |
346 | static u16 lm77_read_value(struct i2c_client *client, u8 reg) | |
347 | { | |
348 | if (reg == LM77_REG_CONF) | |
349 | return i2c_smbus_read_byte_data(client, reg); | |
350 | else | |
351 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
352 | } | |
353 | ||
354 | static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value) | |
355 | { | |
356 | if (reg == LM77_REG_CONF) | |
357 | return i2c_smbus_write_byte_data(client, reg, value); | |
358 | else | |
359 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
360 | } | |
361 | ||
362 | static void lm77_init_client(struct i2c_client *client) | |
363 | { | |
364 | /* Initialize the LM77 chip - turn off shutdown mode */ | |
365 | int conf = lm77_read_value(client, LM77_REG_CONF); | |
366 | if (conf & 1) | |
367 | lm77_write_value(client, LM77_REG_CONF, conf & 0xfe); | |
368 | } | |
369 | ||
370 | static struct lm77_data *lm77_update_device(struct device *dev) | |
371 | { | |
372 | struct i2c_client *client = to_i2c_client(dev); | |
373 | struct lm77_data *data = i2c_get_clientdata(client); | |
374 | ||
375 | down(&data->update_lock); | |
376 | ||
377 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
378 | || !data->valid) { | |
379 | dev_dbg(&client->dev, "Starting lm77 update\n"); | |
380 | data->temp_input = | |
381 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
382 | LM77_REG_TEMP)); | |
383 | data->temp_hyst = | |
384 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
385 | LM77_REG_TEMP_HYST)); | |
386 | data->temp_crit = | |
387 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
388 | LM77_REG_TEMP_CRIT)); | |
389 | data->temp_min = | |
390 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
391 | LM77_REG_TEMP_MIN)); | |
392 | data->temp_max = | |
393 | LM77_TEMP_FROM_REG(lm77_read_value(client, | |
394 | LM77_REG_TEMP_MAX)); | |
395 | data->alarms = | |
396 | lm77_read_value(client, LM77_REG_TEMP) & 0x0007; | |
397 | data->last_updated = jiffies; | |
398 | data->valid = 1; | |
399 | } | |
400 | ||
401 | up(&data->update_lock); | |
402 | ||
403 | return data; | |
404 | } | |
405 | ||
406 | static int __init sensors_lm77_init(void) | |
407 | { | |
408 | return i2c_add_driver(&lm77_driver); | |
409 | } | |
410 | ||
411 | static void __exit sensors_lm77_exit(void) | |
412 | { | |
413 | i2c_del_driver(&lm77_driver); | |
414 | } | |
415 | ||
416 | MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>"); | |
417 | MODULE_DESCRIPTION("LM77 driver"); | |
418 | MODULE_LICENSE("GPL"); | |
419 | ||
420 | module_init(sensors_lm77_init); | |
421 | module_exit(sensors_lm77_exit); |