2 lm75.c - Part of lm_sensors, Linux kernel modules for hardware
4 Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/jiffies.h>
25 #include <linux/i2c.h>
26 #include <linux/hwmon.h>
27 #include <linux/hwmon-sysfs.h>
28 #include <linux/err.h>
29 #include <linux/mutex.h>
34 * This driver handles the LM75 and compatible digital temperature sensors.
35 * Only types which are _not_ listed in I2C_CLIENT_INSMOD_*() need to be
36 * listed here. We start at 9 since I2C_CLIENT_INSMOD_*() currently allow
37 * definition of up to 8 chip types (plus zero).
40 enum lm75_type
{ /* keep sorted in alphabetical order */
43 /* lm75 -- in I2C_CLIENT_INSMOD_1() */
57 /* Addresses scanned by legacy style driver binding */
58 static const unsigned short normal_i2c
[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
59 0x4d, 0x4e, 0x4f, I2C_CLIENT_END
};
61 /* Insmod parameters (only for legacy style driver binding) */
62 I2C_CLIENT_INSMOD_1(lm75
);
65 /* The LM75 registers */
66 #define LM75_REG_CONF 0x01
67 static const u8 LM75_REG_TEMP
[3] = {
73 /* Each client has this additional data */
75 struct i2c_client
*client
;
76 struct device
*hwmon_dev
;
77 struct mutex update_lock
;
79 char valid
; /* !=0 if registers are valid */
80 unsigned long last_updated
; /* In jiffies */
81 u16 temp
[3]; /* Register values,
87 static int lm75_read_value(struct i2c_client
*client
, u8 reg
);
88 static int lm75_write_value(struct i2c_client
*client
, u8 reg
, u16 value
);
89 static struct lm75_data
*lm75_update_device(struct device
*dev
);
92 /*-----------------------------------------------------------------------*/
94 /* sysfs attributes for hwmon */
96 static ssize_t
show_temp(struct device
*dev
, struct device_attribute
*da
,
99 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
100 struct lm75_data
*data
= lm75_update_device(dev
);
101 return sprintf(buf
, "%d\n",
102 LM75_TEMP_FROM_REG(data
->temp
[attr
->index
]));
105 static ssize_t
set_temp(struct device
*dev
, struct device_attribute
*da
,
106 const char *buf
, size_t count
)
108 struct sensor_device_attribute
*attr
= to_sensor_dev_attr(da
);
109 struct i2c_client
*client
= to_i2c_client(dev
);
110 struct lm75_data
*data
= i2c_get_clientdata(client
);
111 int nr
= attr
->index
;
112 long temp
= simple_strtol(buf
, NULL
, 10);
114 mutex_lock(&data
->update_lock
);
115 data
->temp
[nr
] = LM75_TEMP_TO_REG(temp
);
116 lm75_write_value(client
, LM75_REG_TEMP
[nr
], data
->temp
[nr
]);
117 mutex_unlock(&data
->update_lock
);
121 static SENSOR_DEVICE_ATTR(temp1_max
, S_IWUSR
| S_IRUGO
,
122 show_temp
, set_temp
, 1);
123 static SENSOR_DEVICE_ATTR(temp1_max_hyst
, S_IWUSR
| S_IRUGO
,
124 show_temp
, set_temp
, 2);
125 static SENSOR_DEVICE_ATTR(temp1_input
, S_IRUGO
, show_temp
, NULL
, 0);
127 static struct attribute
*lm75_attributes
[] = {
128 &sensor_dev_attr_temp1_input
.dev_attr
.attr
,
129 &sensor_dev_attr_temp1_max
.dev_attr
.attr
,
130 &sensor_dev_attr_temp1_max_hyst
.dev_attr
.attr
,
135 static const struct attribute_group lm75_group
= {
136 .attrs
= lm75_attributes
,
139 /*-----------------------------------------------------------------------*/
141 /* "New style" I2C driver binding -- following the driver model */
144 lm75_probe(struct i2c_client
*client
, const struct i2c_device_id
*id
)
146 struct lm75_data
*data
;
148 u8 set_mask
, clr_mask
;
151 if (!i2c_check_functionality(client
->adapter
,
152 I2C_FUNC_SMBUS_BYTE_DATA
| I2C_FUNC_SMBUS_WORD_DATA
))
155 data
= kzalloc(sizeof(struct lm75_data
), GFP_KERNEL
);
159 i2c_set_clientdata(client
, data
);
161 data
->client
= client
;
162 mutex_init(&data
->update_lock
);
164 /* Set to LM75 resolution (9 bits, 1/2 degree C) and range.
165 * Then tweak to be more precise when appropriate.
168 clr_mask
= (1 << 0) /* continuous conversions */
169 | (1 << 6) | (1 << 5); /* 9-bit mode */
171 /* configure as specified */
172 status
= lm75_read_value(client
, LM75_REG_CONF
);
174 dev_dbg(&client
->dev
, "Can't read config? %d\n", status
);
177 data
->orig_conf
= status
;
178 new = status
& ~clr_mask
;
181 lm75_write_value(client
, LM75_REG_CONF
, new);
182 dev_dbg(&client
->dev
, "Config %02x\n", new);
184 /* Register sysfs hooks */
185 status
= sysfs_create_group(&client
->dev
.kobj
, &lm75_group
);
189 data
->hwmon_dev
= hwmon_device_register(&client
->dev
);
190 if (IS_ERR(data
->hwmon_dev
)) {
191 status
= PTR_ERR(data
->hwmon_dev
);
195 dev_info(&client
->dev
, "%s: sensor '%s'\n",
196 data
->hwmon_dev
->bus_id
, client
->name
);
201 sysfs_remove_group(&client
->dev
.kobj
, &lm75_group
);
203 i2c_set_clientdata(client
, NULL
);
208 static int lm75_remove(struct i2c_client
*client
)
210 struct lm75_data
*data
= i2c_get_clientdata(client
);
212 hwmon_device_unregister(data
->hwmon_dev
);
213 sysfs_remove_group(&client
->dev
.kobj
, &lm75_group
);
214 lm75_write_value(client
, LM75_REG_CONF
, data
->orig_conf
);
215 i2c_set_clientdata(client
, NULL
);
220 static const struct i2c_device_id lm75_ids
[] = {
221 { "ds1775", ds1775
, },
225 { "max6625", max6625
, },
226 { "max6626", max6626
, },
227 { "mcp980x", mcp980x
, },
228 { "stds75", stds75
, },
230 { "tmp100", tmp100
, },
231 { "tmp101", tmp101
, },
232 { "tmp175", tmp175
, },
233 { "tmp275", tmp275
, },
237 MODULE_DEVICE_TABLE(i2c
, lm75_ids
);
239 static struct i2c_driver lm75_driver
= {
244 .remove
= lm75_remove
,
245 .id_table
= lm75_ids
,
248 /*-----------------------------------------------------------------------*/
250 /* "Legacy" I2C driver binding */
252 static struct i2c_driver lm75_legacy_driver
;
254 /* This function is called by i2c_probe */
255 static int lm75_detect(struct i2c_adapter
*adapter
, int address
, int kind
)
258 struct i2c_client
*new_client
;
261 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_BYTE_DATA
|
262 I2C_FUNC_SMBUS_WORD_DATA
))
265 /* OK. For now, we presume we have a valid address. We create the
266 client structure, even though there may be no sensor present.
267 But it allows us to use i2c_smbus_read_*_data() calls. */
268 new_client
= kzalloc(sizeof *new_client
, GFP_KERNEL
);
274 new_client
->addr
= address
;
275 new_client
->adapter
= adapter
;
276 new_client
->driver
= &lm75_legacy_driver
;
277 new_client
->flags
= 0;
279 /* Now, we do the remaining detection. There is no identification-
280 dedicated register so we have to rely on several tricks:
281 unused bits, registers cycling over 8-address boundaries,
282 addresses 0x04-0x07 returning the last read value.
283 The cycling+unused addresses combination is not tested,
284 since it would significantly slow the detection down and would
285 hardly add any value. */
287 int cur
, conf
, hyst
, os
;
289 /* Unused addresses */
290 cur
= i2c_smbus_read_word_data(new_client
, 0);
291 conf
= i2c_smbus_read_byte_data(new_client
, 1);
292 hyst
= i2c_smbus_read_word_data(new_client
, 2);
293 if (i2c_smbus_read_word_data(new_client
, 4) != hyst
294 || i2c_smbus_read_word_data(new_client
, 5) != hyst
295 || i2c_smbus_read_word_data(new_client
, 6) != hyst
296 || i2c_smbus_read_word_data(new_client
, 7) != hyst
)
298 os
= i2c_smbus_read_word_data(new_client
, 3);
299 if (i2c_smbus_read_word_data(new_client
, 4) != os
300 || i2c_smbus_read_word_data(new_client
, 5) != os
301 || i2c_smbus_read_word_data(new_client
, 6) != os
302 || i2c_smbus_read_word_data(new_client
, 7) != os
)
309 /* Addresses cycling */
310 for (i
= 8; i
< 0xff; i
+= 8)
311 if (i2c_smbus_read_byte_data(new_client
, i
+ 1) != conf
312 || i2c_smbus_read_word_data(new_client
, i
+ 2) != hyst
313 || i2c_smbus_read_word_data(new_client
, i
+ 3) != os
)
317 /* NOTE: we treat "force=..." and "force_lm75=..." the same.
318 * Only new-style driver binding distinguishes chip types.
320 strlcpy(new_client
->name
, "lm75", I2C_NAME_SIZE
);
322 /* Tell the I2C layer a new client has arrived */
323 err
= i2c_attach_client(new_client
);
327 err
= lm75_probe(new_client
, NULL
);
334 i2c_detach_client(new_client
);
341 static int lm75_attach_adapter(struct i2c_adapter
*adapter
)
343 if (!(adapter
->class & I2C_CLASS_HWMON
))
345 return i2c_probe(adapter
, &addr_data
, lm75_detect
);
348 static int lm75_detach_client(struct i2c_client
*client
)
351 i2c_detach_client(client
);
356 static struct i2c_driver lm75_legacy_driver
= {
358 .name
= "lm75_legacy",
360 .attach_adapter
= lm75_attach_adapter
,
361 .detach_client
= lm75_detach_client
,
364 /*-----------------------------------------------------------------------*/
366 /* register access */
368 /* All registers are word-sized, except for the configuration register.
369 LM75 uses a high-byte first convention, which is exactly opposite to
370 the SMBus standard. */
371 static int lm75_read_value(struct i2c_client
*client
, u8 reg
)
375 if (reg
== LM75_REG_CONF
)
376 return i2c_smbus_read_byte_data(client
, reg
);
378 value
= i2c_smbus_read_word_data(client
, reg
);
379 return (value
< 0) ? value
: swab16(value
);
382 static int lm75_write_value(struct i2c_client
*client
, u8 reg
, u16 value
)
384 if (reg
== LM75_REG_CONF
)
385 return i2c_smbus_write_byte_data(client
, reg
, value
);
387 return i2c_smbus_write_word_data(client
, reg
, swab16(value
));
390 static struct lm75_data
*lm75_update_device(struct device
*dev
)
392 struct i2c_client
*client
= to_i2c_client(dev
);
393 struct lm75_data
*data
= i2c_get_clientdata(client
);
395 mutex_lock(&data
->update_lock
);
397 if (time_after(jiffies
, data
->last_updated
+ HZ
+ HZ
/ 2)
400 dev_dbg(&client
->dev
, "Starting lm75 update\n");
402 for (i
= 0; i
< ARRAY_SIZE(data
->temp
); i
++) {
405 status
= lm75_read_value(client
, LM75_REG_TEMP
[i
]);
407 dev_dbg(&client
->dev
, "reg %d, err %d\n",
408 LM75_REG_TEMP
[i
], status
);
410 data
->temp
[i
] = status
;
412 data
->last_updated
= jiffies
;
416 mutex_unlock(&data
->update_lock
);
421 /*-----------------------------------------------------------------------*/
425 static int __init
sensors_lm75_init(void)
429 status
= i2c_add_driver(&lm75_driver
);
433 status
= i2c_add_driver(&lm75_legacy_driver
);
435 i2c_del_driver(&lm75_driver
);
440 static void __exit
sensors_lm75_exit(void)
442 i2c_del_driver(&lm75_legacy_driver
);
443 i2c_del_driver(&lm75_driver
);
446 MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>");
447 MODULE_DESCRIPTION("LM75 driver");
448 MODULE_LICENSE("GPL");
450 module_init(sensors_lm75_init
);
451 module_exit(sensors_lm75_exit
);