1 /* Texas Instruments TMP102 SMBus temperature sensor driver
3 * Copyright (C) 2010 Steven King <sfking@fdwdc.com>
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
20 #include <linux/module.h>
21 #include <linux/init.h>
22 #include <linux/slab.h>
23 #include <linux/i2c.h>
24 #include <linux/hwmon.h>
25 #include <linux/hwmon-sysfs.h>
26 #include <linux/err.h>
27 #include <linux/mutex.h>
28 #include <linux/device.h>
30 #define DRIVER_NAME "tmp102"
32 #define TMP102_TEMP_REG 0x00
33 #define TMP102_CONF_REG 0x01
34 /* note: these bit definitions are byte swapped */
35 #define TMP102_CONF_SD 0x0100
36 #define TMP102_CONF_TM 0x0200
37 #define TMP102_CONF_POL 0x0400
38 #define TMP102_CONF_F0 0x0800
39 #define TMP102_CONF_F1 0x1000
40 #define TMP102_CONF_R0 0x2000
41 #define TMP102_CONF_R1 0x4000
42 #define TMP102_CONF_OS 0x8000
43 #define TMP102_CONF_EM 0x0010
44 #define TMP102_CONF_AL 0x0020
45 #define TMP102_CONF_CR0 0x0040
46 #define TMP102_CONF_CR1 0x0080
47 #define TMP102_TLOW_REG 0x02
48 #define TMP102_THIGH_REG 0x03
51 struct device
*hwmon_dev
;
54 unsigned long last_update
;
58 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
59 static inline int tmp102_reg_to_mC(s16 val
)
61 return ((val
& ~0x01) * 1000) / 128;
64 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
65 static inline u16
tmp102_mC_to_reg(int val
)
67 return (val
* 128) / 1000;
70 static const u8 tmp102_reg
[] = {
76 static struct tmp102
*tmp102_update_device(struct i2c_client
*client
)
78 struct tmp102
*tmp102
= i2c_get_clientdata(client
);
80 mutex_lock(&tmp102
->lock
);
81 if (time_after(jiffies
, tmp102
->last_update
+ HZ
/ 3)) {
83 for (i
= 0; i
< ARRAY_SIZE(tmp102
->temp
); ++i
) {
84 int status
= i2c_smbus_read_word_swapped(client
,
87 tmp102
->temp
[i
] = tmp102_reg_to_mC(status
);
89 tmp102
->last_update
= jiffies
;
91 mutex_unlock(&tmp102
->lock
);
95 static ssize_t
tmp102_show_temp(struct device
*dev
,
96 struct device_attribute
*attr
,
99 struct sensor_device_attribute
*sda
= to_sensor_dev_attr(attr
);
100 struct tmp102
*tmp102
= tmp102_update_device(to_i2c_client(dev
));
102 return sprintf(buf
, "%d\n", tmp102
->temp
[sda
->index
]);
105 static ssize_t
tmp102_set_temp(struct device
*dev
,
106 struct device_attribute
*attr
,
107 const char *buf
, size_t count
)
109 struct sensor_device_attribute
*sda
= to_sensor_dev_attr(attr
);
110 struct i2c_client
*client
= to_i2c_client(dev
);
111 struct tmp102
*tmp102
= i2c_get_clientdata(client
);
115 if (strict_strtol(buf
, 10, &val
) < 0)
117 val
= SENSORS_LIMIT(val
, -256000, 255000);
119 mutex_lock(&tmp102
->lock
);
120 tmp102
->temp
[sda
->index
] = val
;
121 status
= i2c_smbus_write_word_swapped(client
, tmp102_reg
[sda
->index
],
122 tmp102_mC_to_reg(val
));
123 mutex_unlock(&tmp102
->lock
);
124 return status
? : count
;
127 static SENSOR_DEVICE_ATTR(temp1_input
, S_IRUGO
, tmp102_show_temp
, NULL
, 0);
129 static SENSOR_DEVICE_ATTR(temp1_max_hyst
, S_IWUSR
| S_IRUGO
, tmp102_show_temp
,
132 static SENSOR_DEVICE_ATTR(temp1_max
, S_IWUSR
| S_IRUGO
, tmp102_show_temp
,
135 static struct attribute
*tmp102_attributes
[] = {
136 &sensor_dev_attr_temp1_input
.dev_attr
.attr
,
137 &sensor_dev_attr_temp1_max_hyst
.dev_attr
.attr
,
138 &sensor_dev_attr_temp1_max
.dev_attr
.attr
,
142 static const struct attribute_group tmp102_attr_group
= {
143 .attrs
= tmp102_attributes
,
146 #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
147 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
149 static int __devinit
tmp102_probe(struct i2c_client
*client
,
150 const struct i2c_device_id
*id
)
152 struct tmp102
*tmp102
;
155 if (!i2c_check_functionality(client
->adapter
,
156 I2C_FUNC_SMBUS_WORD_DATA
)) {
157 dev_err(&client
->dev
, "adapter doesn't support SMBus word "
162 tmp102
= kzalloc(sizeof(*tmp102
), GFP_KERNEL
);
164 dev_dbg(&client
->dev
, "kzalloc failed\n");
167 i2c_set_clientdata(client
, tmp102
);
169 status
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
171 dev_err(&client
->dev
, "error reading config register\n");
174 tmp102
->config_orig
= status
;
175 status
= i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
,
178 dev_err(&client
->dev
, "error writing config register\n");
179 goto fail_restore_config
;
181 status
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
183 dev_err(&client
->dev
, "error reading config register\n");
184 goto fail_restore_config
;
186 status
&= ~TMP102_CONFIG_RD_ONLY
;
187 if (status
!= TMP102_CONFIG
) {
188 dev_err(&client
->dev
, "config settings did not stick\n");
190 goto fail_restore_config
;
192 tmp102
->last_update
= jiffies
- HZ
;
193 mutex_init(&tmp102
->lock
);
195 status
= sysfs_create_group(&client
->dev
.kobj
, &tmp102_attr_group
);
197 dev_dbg(&client
->dev
, "could not create sysfs files\n");
198 goto fail_restore_config
;
200 tmp102
->hwmon_dev
= hwmon_device_register(&client
->dev
);
201 if (IS_ERR(tmp102
->hwmon_dev
)) {
202 dev_dbg(&client
->dev
, "unable to register hwmon device\n");
203 status
= PTR_ERR(tmp102
->hwmon_dev
);
204 goto fail_remove_sysfs
;
207 dev_info(&client
->dev
, "initialized\n");
212 sysfs_remove_group(&client
->dev
.kobj
, &tmp102_attr_group
);
214 i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
,
215 tmp102
->config_orig
);
222 static int __devexit
tmp102_remove(struct i2c_client
*client
)
224 struct tmp102
*tmp102
= i2c_get_clientdata(client
);
226 hwmon_device_unregister(tmp102
->hwmon_dev
);
227 sysfs_remove_group(&client
->dev
.kobj
, &tmp102_attr_group
);
229 /* Stop monitoring if device was stopped originally */
230 if (tmp102
->config_orig
& TMP102_CONF_SD
) {
233 config
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
235 i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
,
236 config
| TMP102_CONF_SD
);
245 static int tmp102_suspend(struct device
*dev
)
247 struct i2c_client
*client
= to_i2c_client(dev
);
250 config
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
254 config
|= TMP102_CONF_SD
;
255 return i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
, config
);
258 static int tmp102_resume(struct device
*dev
)
260 struct i2c_client
*client
= to_i2c_client(dev
);
263 config
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
267 config
&= ~TMP102_CONF_SD
;
268 return i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
, config
);
271 static const struct dev_pm_ops tmp102_dev_pm_ops
= {
272 .suspend
= tmp102_suspend
,
273 .resume
= tmp102_resume
,
276 #define TMP102_DEV_PM_OPS (&tmp102_dev_pm_ops)
278 #define TMP102_DEV_PM_OPS NULL
279 #endif /* CONFIG_PM */
281 static const struct i2c_device_id tmp102_id
[] = {
285 MODULE_DEVICE_TABLE(i2c
, tmp102_id
);
287 static struct i2c_driver tmp102_driver
= {
288 .driver
.name
= DRIVER_NAME
,
289 .driver
.pm
= TMP102_DEV_PM_OPS
,
290 .probe
= tmp102_probe
,
291 .remove
= __devexit_p(tmp102_remove
),
292 .id_table
= tmp102_id
,
295 static int __init
tmp102_init(void)
297 return i2c_add_driver(&tmp102_driver
);
299 module_init(tmp102_init
);
301 static void __exit
tmp102_exit(void)
303 i2c_del_driver(&tmp102_driver
);
305 module_exit(tmp102_exit
);
307 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
308 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
309 MODULE_LICENSE("GPL");