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>
29 #include <linux/jiffies.h>
30 #include <linux/thermal.h>
33 #define DRIVER_NAME "tmp102"
35 #define TMP102_TEMP_REG 0x00
36 #define TMP102_CONF_REG 0x01
37 /* note: these bit definitions are byte swapped */
38 #define TMP102_CONF_SD 0x0100
39 #define TMP102_CONF_TM 0x0200
40 #define TMP102_CONF_POL 0x0400
41 #define TMP102_CONF_F0 0x0800
42 #define TMP102_CONF_F1 0x1000
43 #define TMP102_CONF_R0 0x2000
44 #define TMP102_CONF_R1 0x4000
45 #define TMP102_CONF_OS 0x8000
46 #define TMP102_CONF_EM 0x0010
47 #define TMP102_CONF_AL 0x0020
48 #define TMP102_CONF_CR0 0x0040
49 #define TMP102_CONF_CR1 0x0080
50 #define TMP102_TLOW_REG 0x02
51 #define TMP102_THIGH_REG 0x03
54 struct i2c_client
*client
;
55 struct device
*hwmon_dev
;
58 unsigned long last_update
;
63 /* convert left adjusted 13-bit TMP102 register value to milliCelsius */
64 static inline int tmp102_reg_to_mC(s16 val
)
66 return ((val
& ~0x01) * 1000) / 128;
69 /* convert milliCelsius to left adjusted 13-bit TMP102 register value */
70 static inline u16
tmp102_mC_to_reg(int val
)
72 return (val
* 128) / 1000;
75 static const u8 tmp102_reg
[] = {
81 static struct tmp102
*tmp102_update_device(struct device
*dev
)
83 struct tmp102
*tmp102
= dev_get_drvdata(dev
);
84 struct i2c_client
*client
= tmp102
->client
;
86 mutex_lock(&tmp102
->lock
);
87 if (time_after(jiffies
, tmp102
->last_update
+ HZ
/ 3)) {
89 for (i
= 0; i
< ARRAY_SIZE(tmp102
->temp
); ++i
) {
90 int status
= i2c_smbus_read_word_swapped(client
,
93 tmp102
->temp
[i
] = tmp102_reg_to_mC(status
);
95 tmp102
->last_update
= jiffies
;
96 tmp102
->first_time
= false;
98 mutex_unlock(&tmp102
->lock
);
102 static int tmp102_read_temp(void *dev
, int *temp
)
104 struct tmp102
*tmp102
= tmp102_update_device(dev
);
106 /* Is it too early even to return a conversion? */
107 if (tmp102
->first_time
) {
108 dev_dbg(dev
, "%s: Conversion not ready yet..\n", __func__
);
112 *temp
= tmp102
->temp
[0];
117 static ssize_t
tmp102_show_temp(struct device
*dev
,
118 struct device_attribute
*attr
,
121 struct sensor_device_attribute
*sda
= to_sensor_dev_attr(attr
);
122 struct tmp102
*tmp102
= tmp102_update_device(dev
);
124 /* Is it too early even to return a read? */
125 if (tmp102
->first_time
)
128 return sprintf(buf
, "%d\n", tmp102
->temp
[sda
->index
]);
131 static ssize_t
tmp102_set_temp(struct device
*dev
,
132 struct device_attribute
*attr
,
133 const char *buf
, size_t count
)
135 struct sensor_device_attribute
*sda
= to_sensor_dev_attr(attr
);
136 struct tmp102
*tmp102
= dev_get_drvdata(dev
);
137 struct i2c_client
*client
= tmp102
->client
;
141 if (kstrtol(buf
, 10, &val
) < 0)
143 val
= clamp_val(val
, -256000, 255000);
145 mutex_lock(&tmp102
->lock
);
146 tmp102
->temp
[sda
->index
] = val
;
147 status
= i2c_smbus_write_word_swapped(client
, tmp102_reg
[sda
->index
],
148 tmp102_mC_to_reg(val
));
149 mutex_unlock(&tmp102
->lock
);
150 return status
? : count
;
153 static SENSOR_DEVICE_ATTR(temp1_input
, S_IRUGO
, tmp102_show_temp
, NULL
, 0);
155 static SENSOR_DEVICE_ATTR(temp1_max_hyst
, S_IWUSR
| S_IRUGO
, tmp102_show_temp
,
158 static SENSOR_DEVICE_ATTR(temp1_max
, S_IWUSR
| S_IRUGO
, tmp102_show_temp
,
161 static struct attribute
*tmp102_attrs
[] = {
162 &sensor_dev_attr_temp1_input
.dev_attr
.attr
,
163 &sensor_dev_attr_temp1_max_hyst
.dev_attr
.attr
,
164 &sensor_dev_attr_temp1_max
.dev_attr
.attr
,
167 ATTRIBUTE_GROUPS(tmp102
);
169 #define TMP102_CONFIG (TMP102_CONF_TM | TMP102_CONF_EM | TMP102_CONF_CR1)
170 #define TMP102_CONFIG_RD_ONLY (TMP102_CONF_R0 | TMP102_CONF_R1 | TMP102_CONF_AL)
172 static const struct thermal_zone_of_device_ops tmp102_of_thermal_ops
= {
173 .get_temp
= tmp102_read_temp
,
176 static int tmp102_probe(struct i2c_client
*client
,
177 const struct i2c_device_id
*id
)
179 struct device
*dev
= &client
->dev
;
180 struct device
*hwmon_dev
;
181 struct tmp102
*tmp102
;
184 if (!i2c_check_functionality(client
->adapter
,
185 I2C_FUNC_SMBUS_WORD_DATA
)) {
187 "adapter doesn't support SMBus word transactions\n");
191 tmp102
= devm_kzalloc(dev
, sizeof(*tmp102
), GFP_KERNEL
);
195 i2c_set_clientdata(client
, tmp102
);
196 tmp102
->client
= client
;
198 status
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
200 dev_err(dev
, "error reading config register\n");
203 tmp102
->config_orig
= status
;
204 status
= i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
,
207 dev_err(dev
, "error writing config register\n");
208 goto fail_restore_config
;
210 status
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
212 dev_err(dev
, "error reading config register\n");
213 goto fail_restore_config
;
215 status
&= ~TMP102_CONFIG_RD_ONLY
;
216 if (status
!= TMP102_CONFIG
) {
217 dev_err(dev
, "config settings did not stick\n");
219 goto fail_restore_config
;
221 tmp102
->last_update
= jiffies
;
222 /* Mark that we are not ready with data until conversion is complete */
223 tmp102
->first_time
= true;
224 mutex_init(&tmp102
->lock
);
226 hwmon_dev
= hwmon_device_register_with_groups(dev
, client
->name
,
227 tmp102
, tmp102_groups
);
228 if (IS_ERR(hwmon_dev
)) {
229 dev_dbg(dev
, "unable to register hwmon device\n");
230 status
= PTR_ERR(hwmon_dev
);
231 goto fail_restore_config
;
233 tmp102
->hwmon_dev
= hwmon_dev
;
234 devm_thermal_zone_of_sensor_register(hwmon_dev
, 0, hwmon_dev
,
235 &tmp102_of_thermal_ops
);
237 dev_info(dev
, "initialized\n");
242 i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
,
243 tmp102
->config_orig
);
247 static int tmp102_remove(struct i2c_client
*client
)
249 struct tmp102
*tmp102
= i2c_get_clientdata(client
);
251 hwmon_device_unregister(tmp102
->hwmon_dev
);
253 /* Stop monitoring if device was stopped originally */
254 if (tmp102
->config_orig
& TMP102_CONF_SD
) {
257 config
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
259 i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
,
260 config
| TMP102_CONF_SD
);
266 #ifdef CONFIG_PM_SLEEP
267 static int tmp102_suspend(struct device
*dev
)
269 struct i2c_client
*client
= to_i2c_client(dev
);
272 config
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
276 config
|= TMP102_CONF_SD
;
277 return i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
, config
);
280 static int tmp102_resume(struct device
*dev
)
282 struct i2c_client
*client
= to_i2c_client(dev
);
285 config
= i2c_smbus_read_word_swapped(client
, TMP102_CONF_REG
);
289 config
&= ~TMP102_CONF_SD
;
290 return i2c_smbus_write_word_swapped(client
, TMP102_CONF_REG
, config
);
292 #endif /* CONFIG_PM */
294 static SIMPLE_DEV_PM_OPS(tmp102_dev_pm_ops
, tmp102_suspend
, tmp102_resume
);
296 static const struct i2c_device_id tmp102_id
[] = {
300 MODULE_DEVICE_TABLE(i2c
, tmp102_id
);
302 static struct i2c_driver tmp102_driver
= {
303 .driver
.name
= DRIVER_NAME
,
304 .driver
.pm
= &tmp102_dev_pm_ops
,
305 .probe
= tmp102_probe
,
306 .remove
= tmp102_remove
,
307 .id_table
= tmp102_id
,
310 module_i2c_driver(tmp102_driver
);
312 MODULE_AUTHOR("Steven King <sfking@fdwdc.com>");
313 MODULE_DESCRIPTION("Texas Instruments TMP102 temperature sensor driver");
314 MODULE_LICENSE("GPL");