2 lm77.c - Part of lm_sensors, Linux kernel modules for hardware
5 Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
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
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.
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.
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.
28 #include <linux/module.h>
29 #include <linux/init.h>
30 #include <linux/slab.h>
31 #include <linux/jiffies.h>
32 #include <linux/i2c.h>
33 #include <linux/i2c-sensor.h>
34 #include <linux/hwmon.h>
35 #include <linux/err.h>
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
};
41 /* Insmod parameters */
42 SENSORS_INSMOD_1(lm77
);
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
52 /* Each client has this additional data */
54 struct i2c_client client
;
55 struct class_device
*class_dev
;
56 struct semaphore update_lock
;
58 unsigned long last_updated
; /* In jiffies */
59 int temp_input
; /* Temperatures */
67 static int lm77_attach_adapter(struct i2c_adapter
*adapter
);
68 static int lm77_detect(struct i2c_adapter
*adapter
, int address
, int kind
);
69 static void lm77_init_client(struct i2c_client
*client
);
70 static int lm77_detach_client(struct i2c_client
*client
);
71 static u16
lm77_read_value(struct i2c_client
*client
, u8 reg
);
72 static int lm77_write_value(struct i2c_client
*client
, u8 reg
, u16 value
);
74 static struct lm77_data
*lm77_update_device(struct device
*dev
);
77 /* This is the driver that will be inserted */
78 static struct i2c_driver lm77_driver
= {
81 .flags
= I2C_DF_NOTIFY
,
82 .attach_adapter
= lm77_attach_adapter
,
83 .detach_client
= lm77_detach_client
,
86 /* straight from the datasheet */
87 #define LM77_TEMP_MIN (-55000)
88 #define LM77_TEMP_MAX 125000
90 /* In the temperature registers, the low 3 bits are not part of the
91 temperature values; they are the status bits. */
92 static inline u16
LM77_TEMP_TO_REG(int temp
)
94 int ntemp
= SENSORS_LIMIT(temp
, LM77_TEMP_MIN
, LM77_TEMP_MAX
);
95 return (u16
)((ntemp
/ 500) * 8);
98 static inline int LM77_TEMP_FROM_REG(u16 reg
)
100 return ((int)reg
/ 8) * 500;
105 /* read routines for temperature limits */
106 #define show(value) \
107 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
109 struct lm77_data *data = lm77_update_device(dev); \
110 return sprintf(buf, "%d\n", data->value); \
119 /* read routines for hysteresis values */
120 static ssize_t
show_temp_crit_hyst(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
122 struct lm77_data
*data
= lm77_update_device(dev
);
123 return sprintf(buf
, "%d\n", data
->temp_crit
- data
->temp_hyst
);
125 static ssize_t
show_temp_min_hyst(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
127 struct lm77_data
*data
= lm77_update_device(dev
);
128 return sprintf(buf
, "%d\n", data
->temp_min
+ data
->temp_hyst
);
130 static ssize_t
show_temp_max_hyst(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
132 struct lm77_data
*data
= lm77_update_device(dev
);
133 return sprintf(buf
, "%d\n", data
->temp_max
- data
->temp_hyst
);
137 #define set(value, reg) \
138 static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
140 struct i2c_client *client = to_i2c_client(dev); \
141 struct lm77_data *data = i2c_get_clientdata(client); \
142 long val = simple_strtoul(buf, NULL, 10); \
144 down(&data->update_lock); \
146 lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
147 up(&data->update_lock); \
151 set(temp_min
, LM77_REG_TEMP_MIN
);
152 set(temp_max
, LM77_REG_TEMP_MAX
);
154 /* hysteresis is stored as a relative value on the chip, so it has to be
156 static ssize_t
set_temp_crit_hyst(struct device
*dev
, struct device_attribute
*attr
, const char *buf
, size_t count
)
158 struct i2c_client
*client
= to_i2c_client(dev
);
159 struct lm77_data
*data
= i2c_get_clientdata(client
);
160 unsigned long val
= simple_strtoul(buf
, NULL
, 10);
162 down(&data
->update_lock
);
163 data
->temp_hyst
= data
->temp_crit
- val
;
164 lm77_write_value(client
, LM77_REG_TEMP_HYST
,
165 LM77_TEMP_TO_REG(data
->temp_hyst
));
166 up(&data
->update_lock
);
170 /* preserve hysteresis when setting T_crit */
171 static ssize_t
set_temp_crit(struct device
*dev
, struct device_attribute
*attr
, const char *buf
, size_t count
)
173 struct i2c_client
*client
= to_i2c_client(dev
);
174 struct lm77_data
*data
= i2c_get_clientdata(client
);
175 long val
= simple_strtoul(buf
, NULL
, 10);
178 down(&data
->update_lock
);
179 oldcrithyst
= data
->temp_crit
- data
->temp_hyst
;
180 data
->temp_crit
= val
;
181 data
->temp_hyst
= data
->temp_crit
- oldcrithyst
;
182 lm77_write_value(client
, LM77_REG_TEMP_CRIT
,
183 LM77_TEMP_TO_REG(data
->temp_crit
));
184 lm77_write_value(client
, LM77_REG_TEMP_HYST
,
185 LM77_TEMP_TO_REG(data
->temp_hyst
));
186 up(&data
->update_lock
);
190 static DEVICE_ATTR(temp1_input
, S_IRUGO
,
191 show_temp_input
, NULL
);
192 static DEVICE_ATTR(temp1_crit
, S_IWUSR
| S_IRUGO
,
193 show_temp_crit
, set_temp_crit
);
194 static DEVICE_ATTR(temp1_min
, S_IWUSR
| S_IRUGO
,
195 show_temp_min
, set_temp_min
);
196 static DEVICE_ATTR(temp1_max
, S_IWUSR
| S_IRUGO
,
197 show_temp_max
, set_temp_max
);
199 static DEVICE_ATTR(temp1_crit_hyst
, S_IWUSR
| S_IRUGO
,
200 show_temp_crit_hyst
, set_temp_crit_hyst
);
201 static DEVICE_ATTR(temp1_min_hyst
, S_IRUGO
,
202 show_temp_min_hyst
, NULL
);
203 static DEVICE_ATTR(temp1_max_hyst
, S_IRUGO
,
204 show_temp_max_hyst
, NULL
);
206 static DEVICE_ATTR(alarms
, S_IRUGO
,
209 static int lm77_attach_adapter(struct i2c_adapter
*adapter
)
211 if (!(adapter
->class & I2C_CLASS_HWMON
))
213 return i2c_detect(adapter
, &addr_data
, lm77_detect
);
216 /* This function is called by i2c_detect */
217 static int lm77_detect(struct i2c_adapter
*adapter
, int address
, int kind
)
219 struct i2c_client
*new_client
;
220 struct lm77_data
*data
;
222 const char *name
= "";
224 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_BYTE_DATA
|
225 I2C_FUNC_SMBUS_WORD_DATA
))
228 /* OK. For now, we presume we have a valid client. We now create the
229 client structure, even though we cannot fill it completely yet.
230 But it allows us to access lm77_{read,write}_value. */
231 if (!(data
= kmalloc(sizeof(struct lm77_data
), GFP_KERNEL
))) {
235 memset(data
, 0, sizeof(struct lm77_data
));
237 new_client
= &data
->client
;
238 i2c_set_clientdata(new_client
, data
);
239 new_client
->addr
= address
;
240 new_client
->adapter
= adapter
;
241 new_client
->driver
= &lm77_driver
;
242 new_client
->flags
= 0;
244 /* Here comes the remaining detection. Since the LM77 has no
245 register dedicated to identification, we have to rely on the
248 1. the high 4 bits represent the sign and thus they should
250 2. the high 3 bits are unused in the configuration register
251 3. addresses 0x06 and 0x07 return the last read value
252 4. registers cycling over 8-address boundaries
254 Word-sized registers are high-byte first. */
256 int i
, cur
, conf
, hyst
, crit
, min
, max
;
258 /* addresses cycling */
259 cur
= i2c_smbus_read_word_data(new_client
, 0);
260 conf
= i2c_smbus_read_byte_data(new_client
, 1);
261 hyst
= i2c_smbus_read_word_data(new_client
, 2);
262 crit
= i2c_smbus_read_word_data(new_client
, 3);
263 min
= i2c_smbus_read_word_data(new_client
, 4);
264 max
= i2c_smbus_read_word_data(new_client
, 5);
265 for (i
= 8; i
<= 0xff; i
+= 8)
266 if (i2c_smbus_read_byte_data(new_client
, i
+ 1) != conf
267 || i2c_smbus_read_word_data(new_client
, i
+ 2) != hyst
268 || i2c_smbus_read_word_data(new_client
, i
+ 3) != crit
269 || i2c_smbus_read_word_data(new_client
, i
+ 4) != min
270 || i2c_smbus_read_word_data(new_client
, i
+ 5) != max
)
274 if (((cur
& 0x00f0) != 0xf0 && (cur
& 0x00f0) != 0x0)
275 || ((hyst
& 0x00f0) != 0xf0 && (hyst
& 0x00f0) != 0x0)
276 || ((crit
& 0x00f0) != 0xf0 && (crit
& 0x00f0) != 0x0)
277 || ((min
& 0x00f0) != 0xf0 && (min
& 0x00f0) != 0x0)
278 || ((max
& 0x00f0) != 0xf0 && (max
& 0x00f0) != 0x0))
285 /* 0x06 and 0x07 return the last read value */
286 cur
= i2c_smbus_read_word_data(new_client
, 0);
287 if (i2c_smbus_read_word_data(new_client
, 6) != cur
288 || i2c_smbus_read_word_data(new_client
, 7) != cur
)
290 hyst
= i2c_smbus_read_word_data(new_client
, 2);
291 if (i2c_smbus_read_word_data(new_client
, 6) != hyst
292 || i2c_smbus_read_word_data(new_client
, 7) != hyst
)
294 min
= i2c_smbus_read_word_data(new_client
, 4);
295 if (i2c_smbus_read_word_data(new_client
, 6) != min
296 || i2c_smbus_read_word_data(new_client
, 7) != min
)
301 /* Determine the chip type - only one kind supported! */
309 /* Fill in the remaining client fields and put it into the global list */
310 strlcpy(new_client
->name
, name
, I2C_NAME_SIZE
);
312 init_MUTEX(&data
->update_lock
);
314 /* Tell the I2C layer a new client has arrived */
315 if ((err
= i2c_attach_client(new_client
)))
318 /* Initialize the LM77 chip */
319 lm77_init_client(new_client
);
321 /* Register sysfs hooks */
322 data
->class_dev
= hwmon_device_register(&new_client
->dev
);
323 if (IS_ERR(data
->class_dev
)) {
324 err
= PTR_ERR(data
->class_dev
);
328 device_create_file(&new_client
->dev
, &dev_attr_temp1_input
);
329 device_create_file(&new_client
->dev
, &dev_attr_temp1_crit
);
330 device_create_file(&new_client
->dev
, &dev_attr_temp1_min
);
331 device_create_file(&new_client
->dev
, &dev_attr_temp1_max
);
332 device_create_file(&new_client
->dev
, &dev_attr_temp1_crit_hyst
);
333 device_create_file(&new_client
->dev
, &dev_attr_temp1_min_hyst
);
334 device_create_file(&new_client
->dev
, &dev_attr_temp1_max_hyst
);
335 device_create_file(&new_client
->dev
, &dev_attr_alarms
);
339 i2c_detach_client(new_client
);
346 static int lm77_detach_client(struct i2c_client
*client
)
348 struct lm77_data
*data
= i2c_get_clientdata(client
);
349 hwmon_device_unregister(data
->class_dev
);
350 i2c_detach_client(client
);
355 /* All registers are word-sized, except for the configuration register.
356 The LM77 uses the high-byte first convention. */
357 static u16
lm77_read_value(struct i2c_client
*client
, u8 reg
)
359 if (reg
== LM77_REG_CONF
)
360 return i2c_smbus_read_byte_data(client
, reg
);
362 return swab16(i2c_smbus_read_word_data(client
, reg
));
365 static int lm77_write_value(struct i2c_client
*client
, u8 reg
, u16 value
)
367 if (reg
== LM77_REG_CONF
)
368 return i2c_smbus_write_byte_data(client
, reg
, value
);
370 return i2c_smbus_write_word_data(client
, reg
, swab16(value
));
373 static void lm77_init_client(struct i2c_client
*client
)
375 /* Initialize the LM77 chip - turn off shutdown mode */
376 int conf
= lm77_read_value(client
, LM77_REG_CONF
);
378 lm77_write_value(client
, LM77_REG_CONF
, conf
& 0xfe);
381 static struct lm77_data
*lm77_update_device(struct device
*dev
)
383 struct i2c_client
*client
= to_i2c_client(dev
);
384 struct lm77_data
*data
= i2c_get_clientdata(client
);
386 down(&data
->update_lock
);
388 if (time_after(jiffies
, data
->last_updated
+ HZ
+ HZ
/ 2)
390 dev_dbg(&client
->dev
, "Starting lm77 update\n");
392 LM77_TEMP_FROM_REG(lm77_read_value(client
,
395 LM77_TEMP_FROM_REG(lm77_read_value(client
,
396 LM77_REG_TEMP_HYST
));
398 LM77_TEMP_FROM_REG(lm77_read_value(client
,
399 LM77_REG_TEMP_CRIT
));
401 LM77_TEMP_FROM_REG(lm77_read_value(client
,
404 LM77_TEMP_FROM_REG(lm77_read_value(client
,
407 lm77_read_value(client
, LM77_REG_TEMP
) & 0x0007;
408 data
->last_updated
= jiffies
;
412 up(&data
->update_lock
);
417 static int __init
sensors_lm77_init(void)
419 return i2c_add_driver(&lm77_driver
);
422 static void __exit
sensors_lm77_exit(void)
424 i2c_del_driver(&lm77_driver
);
427 MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
428 MODULE_DESCRIPTION("LM77 driver");
429 MODULE_LICENSE("GPL");
431 module_init(sensors_lm77_init
);
432 module_exit(sensors_lm77_exit
);
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