blob: 9380fda7dcd129015af886f1360b650f216aad78 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/module.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/jiffies.h>
32#include <linux/i2c.h>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040033#include <linux/hwmon.h>
34#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36/* Addresses to scan */
37static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
39/* Insmod parameters */
Jean Delvaref4b50262005-07-31 21:49:03 +020040I2C_CLIENT_INSMOD_1(lm77);
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
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 */
51struct lm77_data {
52 struct i2c_client client;
Mark M. Hoffman943b0832005-07-15 21:39:18 -040053 struct class_device *class_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 struct semaphore update_lock;
55 char valid;
56 unsigned long last_updated; /* In jiffies */
57 int temp_input; /* Temperatures */
58 int temp_crit;
59 int temp_min;
60 int temp_max;
61 int temp_hyst;
62 u8 alarms;
63};
64
65static int lm77_attach_adapter(struct i2c_adapter *adapter);
66static int lm77_detect(struct i2c_adapter *adapter, int address, int kind);
67static void lm77_init_client(struct i2c_client *client);
68static int lm77_detach_client(struct i2c_client *client);
69static u16 lm77_read_value(struct i2c_client *client, u8 reg);
70static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
71
72static struct lm77_data *lm77_update_device(struct device *dev);
73
74
75/* This is the driver that will be inserted */
76static struct i2c_driver lm77_driver = {
77 .owner = THIS_MODULE,
78 .name = "lm77",
79 .flags = I2C_DF_NOTIFY,
80 .attach_adapter = lm77_attach_adapter,
81 .detach_client = lm77_detach_client,
82};
83
84/* straight from the datasheet */
85#define LM77_TEMP_MIN (-55000)
86#define LM77_TEMP_MAX 125000
87
88/* In the temperature registers, the low 3 bits are not part of the
89 temperature values; they are the status bits. */
90static inline u16 LM77_TEMP_TO_REG(int temp)
91{
92 int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
93 return (u16)((ntemp / 500) * 8);
94}
95
96static inline int LM77_TEMP_FROM_REG(u16 reg)
97{
98 return ((int)reg / 8) * 500;
99}
100
101/* sysfs stuff */
102
103/* read routines for temperature limits */
104#define show(value) \
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400105static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106{ \
107 struct lm77_data *data = lm77_update_device(dev); \
108 return sprintf(buf, "%d\n", data->value); \
109}
110
111show(temp_input);
112show(temp_crit);
113show(temp_min);
114show(temp_max);
115show(alarms);
116
117/* read routines for hysteresis values */
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400118static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119{
120 struct lm77_data *data = lm77_update_device(dev);
121 return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
122}
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400123static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124{
125 struct lm77_data *data = lm77_update_device(dev);
126 return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
127}
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400128static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129{
130 struct lm77_data *data = lm77_update_device(dev);
131 return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
132}
133
134/* write routines */
135#define set(value, reg) \
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400136static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137{ \
138 struct i2c_client *client = to_i2c_client(dev); \
139 struct lm77_data *data = i2c_get_clientdata(client); \
140 long val = simple_strtoul(buf, NULL, 10); \
141 \
142 down(&data->update_lock); \
143 data->value = val; \
144 lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
145 up(&data->update_lock); \
146 return count; \
147}
148
149set(temp_min, LM77_REG_TEMP_MIN);
150set(temp_max, LM77_REG_TEMP_MAX);
151
152/* hysteresis is stored as a relative value on the chip, so it has to be
153 converted first */
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400154static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155{
156 struct i2c_client *client = to_i2c_client(dev);
157 struct lm77_data *data = i2c_get_clientdata(client);
158 unsigned long val = simple_strtoul(buf, NULL, 10);
159
160 down(&data->update_lock);
161 data->temp_hyst = data->temp_crit - val;
162 lm77_write_value(client, LM77_REG_TEMP_HYST,
163 LM77_TEMP_TO_REG(data->temp_hyst));
164 up(&data->update_lock);
165 return count;
166}
167
168/* preserve hysteresis when setting T_crit */
Yani Ioannou8627f9b2005-05-17 06:42:03 -0400169static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170{
171 struct i2c_client *client = to_i2c_client(dev);
172 struct lm77_data *data = i2c_get_clientdata(client);
173 long val = simple_strtoul(buf, NULL, 10);
174 int oldcrithyst;
175
176 down(&data->update_lock);
177 oldcrithyst = data->temp_crit - data->temp_hyst;
178 data->temp_crit = val;
179 data->temp_hyst = data->temp_crit - oldcrithyst;
180 lm77_write_value(client, LM77_REG_TEMP_CRIT,
181 LM77_TEMP_TO_REG(data->temp_crit));
182 lm77_write_value(client, LM77_REG_TEMP_HYST,
183 LM77_TEMP_TO_REG(data->temp_hyst));
184 up(&data->update_lock);
185 return count;
186}
187
188static DEVICE_ATTR(temp1_input, S_IRUGO,
189 show_temp_input, NULL);
190static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
191 show_temp_crit, set_temp_crit);
192static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
193 show_temp_min, set_temp_min);
194static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
195 show_temp_max, set_temp_max);
196
197static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
198 show_temp_crit_hyst, set_temp_crit_hyst);
199static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
200 show_temp_min_hyst, NULL);
201static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
202 show_temp_max_hyst, NULL);
203
204static DEVICE_ATTR(alarms, S_IRUGO,
205 show_alarms, NULL);
206
207static int lm77_attach_adapter(struct i2c_adapter *adapter)
208{
209 if (!(adapter->class & I2C_CLASS_HWMON))
210 return 0;
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200211 return i2c_probe(adapter, &addr_data, lm77_detect);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212}
213
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200214/* This function is called by i2c_probe */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215static int lm77_detect(struct i2c_adapter *adapter, int address, int kind)
216{
217 struct i2c_client *new_client;
218 struct lm77_data *data;
219 int err = 0;
220 const char *name = "";
221
222 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
223 I2C_FUNC_SMBUS_WORD_DATA))
224 goto exit;
225
226 /* OK. For now, we presume we have a valid client. We now create the
227 client structure, even though we cannot fill it completely yet.
228 But it allows us to access lm77_{read,write}_value. */
Deepak Saxenaba9c2e82005-10-17 23:08:32 +0200229 if (!(data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 err = -ENOMEM;
231 goto exit;
232 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233
234 new_client = &data->client;
235 i2c_set_clientdata(new_client, data);
236 new_client->addr = address;
237 new_client->adapter = adapter;
238 new_client->driver = &lm77_driver;
239 new_client->flags = 0;
240
241 /* Here comes the remaining detection. Since the LM77 has no
242 register dedicated to identification, we have to rely on the
243 following tricks:
244
245 1. the high 4 bits represent the sign and thus they should
246 always be the same
247 2. the high 3 bits are unused in the configuration register
248 3. addresses 0x06 and 0x07 return the last read value
249 4. registers cycling over 8-address boundaries
250
251 Word-sized registers are high-byte first. */
252 if (kind < 0) {
253 int i, cur, conf, hyst, crit, min, max;
254
255 /* addresses cycling */
256 cur = i2c_smbus_read_word_data(new_client, 0);
257 conf = i2c_smbus_read_byte_data(new_client, 1);
258 hyst = i2c_smbus_read_word_data(new_client, 2);
259 crit = i2c_smbus_read_word_data(new_client, 3);
260 min = i2c_smbus_read_word_data(new_client, 4);
261 max = i2c_smbus_read_word_data(new_client, 5);
262 for (i = 8; i <= 0xff; i += 8)
263 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
264 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
265 || i2c_smbus_read_word_data(new_client, i + 3) != crit
266 || i2c_smbus_read_word_data(new_client, i + 4) != min
267 || i2c_smbus_read_word_data(new_client, i + 5) != max)
268 goto exit_free;
269
270 /* sign bits */
271 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
272 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
273 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
274 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
275 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
276 goto exit_free;
277
278 /* unused bits */
279 if (conf & 0xe0)
280 goto exit_free;
281
282 /* 0x06 and 0x07 return the last read value */
283 cur = i2c_smbus_read_word_data(new_client, 0);
284 if (i2c_smbus_read_word_data(new_client, 6) != cur
285 || i2c_smbus_read_word_data(new_client, 7) != cur)
286 goto exit_free;
287 hyst = i2c_smbus_read_word_data(new_client, 2);
288 if (i2c_smbus_read_word_data(new_client, 6) != hyst
289 || i2c_smbus_read_word_data(new_client, 7) != hyst)
290 goto exit_free;
291 min = i2c_smbus_read_word_data(new_client, 4);
292 if (i2c_smbus_read_word_data(new_client, 6) != min
293 || i2c_smbus_read_word_data(new_client, 7) != min)
294 goto exit_free;
295
296 }
297
298 /* Determine the chip type - only one kind supported! */
299 if (kind <= 0)
300 kind = lm77;
301
302 if (kind == lm77) {
303 name = "lm77";
304 }
305
306 /* Fill in the remaining client fields and put it into the global list */
307 strlcpy(new_client->name, name, I2C_NAME_SIZE);
308 data->valid = 0;
309 init_MUTEX(&data->update_lock);
310
311 /* Tell the I2C layer a new client has arrived */
312 if ((err = i2c_attach_client(new_client)))
313 goto exit_free;
314
315 /* Initialize the LM77 chip */
316 lm77_init_client(new_client);
317
318 /* Register sysfs hooks */
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400319 data->class_dev = hwmon_device_register(&new_client->dev);
320 if (IS_ERR(data->class_dev)) {
321 err = PTR_ERR(data->class_dev);
322 goto exit_detach;
323 }
324
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325 device_create_file(&new_client->dev, &dev_attr_temp1_input);
326 device_create_file(&new_client->dev, &dev_attr_temp1_crit);
327 device_create_file(&new_client->dev, &dev_attr_temp1_min);
328 device_create_file(&new_client->dev, &dev_attr_temp1_max);
329 device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst);
330 device_create_file(&new_client->dev, &dev_attr_temp1_min_hyst);
331 device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
332 device_create_file(&new_client->dev, &dev_attr_alarms);
333 return 0;
334
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400335exit_detach:
336 i2c_detach_client(new_client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337exit_free:
338 kfree(data);
339exit:
340 return err;
341}
342
343static int lm77_detach_client(struct i2c_client *client)
344{
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400345 struct lm77_data *data = i2c_get_clientdata(client);
346 hwmon_device_unregister(data->class_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 i2c_detach_client(client);
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400348 kfree(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 return 0;
350}
351
352/* All registers are word-sized, except for the configuration register.
353 The LM77 uses the high-byte first convention. */
354static u16 lm77_read_value(struct i2c_client *client, u8 reg)
355{
356 if (reg == LM77_REG_CONF)
357 return i2c_smbus_read_byte_data(client, reg);
358 else
359 return swab16(i2c_smbus_read_word_data(client, reg));
360}
361
362static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
363{
364 if (reg == LM77_REG_CONF)
365 return i2c_smbus_write_byte_data(client, reg, value);
366 else
367 return i2c_smbus_write_word_data(client, reg, swab16(value));
368}
369
370static void lm77_init_client(struct i2c_client *client)
371{
372 /* Initialize the LM77 chip - turn off shutdown mode */
373 int conf = lm77_read_value(client, LM77_REG_CONF);
374 if (conf & 1)
375 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
376}
377
378static struct lm77_data *lm77_update_device(struct device *dev)
379{
380 struct i2c_client *client = to_i2c_client(dev);
381 struct lm77_data *data = i2c_get_clientdata(client);
382
383 down(&data->update_lock);
384
385 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
386 || !data->valid) {
387 dev_dbg(&client->dev, "Starting lm77 update\n");
388 data->temp_input =
389 LM77_TEMP_FROM_REG(lm77_read_value(client,
390 LM77_REG_TEMP));
391 data->temp_hyst =
392 LM77_TEMP_FROM_REG(lm77_read_value(client,
393 LM77_REG_TEMP_HYST));
394 data->temp_crit =
395 LM77_TEMP_FROM_REG(lm77_read_value(client,
396 LM77_REG_TEMP_CRIT));
397 data->temp_min =
398 LM77_TEMP_FROM_REG(lm77_read_value(client,
399 LM77_REG_TEMP_MIN));
400 data->temp_max =
401 LM77_TEMP_FROM_REG(lm77_read_value(client,
402 LM77_REG_TEMP_MAX));
403 data->alarms =
404 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
405 data->last_updated = jiffies;
406 data->valid = 1;
407 }
408
409 up(&data->update_lock);
410
411 return data;
412}
413
414static int __init sensors_lm77_init(void)
415{
416 return i2c_add_driver(&lm77_driver);
417}
418
419static void __exit sensors_lm77_exit(void)
420{
421 i2c_del_driver(&lm77_driver);
422}
423
424MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
425MODULE_DESCRIPTION("LM77 driver");
426MODULE_LICENSE("GPL");
427
428module_init(sensors_lm77_init);
429module_exit(sensors_lm77_exit);