3 * Copyright (C) 2009 Andre Prendel <andre.prendel@gmx.de>
4 * Preliminary support by:
5 * Melvin Rook, Raymond Ng
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 * Driver for the Texas Instruments TMP421 SMBus temperature sensor IC.
24 * Supported models: TMP421, TMP422, TMP423
27 #include <linux/module.h>
28 #include <linux/init.h>
29 #include <linux/slab.h>
30 #include <linux/jiffies.h>
31 #include <linux/i2c.h>
32 #include <linux/hwmon.h>
33 #include <linux/hwmon-sysfs.h>
34 #include <linux/err.h>
35 #include <linux/mutex.h>
36 #include <linux/sysfs.h>
38 /* Addresses to scan */
39 static const unsigned short normal_i2c
[] = { 0x2a, 0x4c, 0x4d, 0x4e, 0x4f,
42 enum chips
{ tmp421
, tmp422
, tmp423
};
44 /* The TMP421 registers */
45 #define TMP421_CONFIG_REG_1 0x09
46 #define TMP421_CONVERSION_RATE_REG 0x0B
47 #define TMP421_MANUFACTURER_ID_REG 0xFE
48 #define TMP421_DEVICE_ID_REG 0xFF
50 static const u8 TMP421_TEMP_MSB
[4] = { 0x00, 0x01, 0x02, 0x03 };
51 static const u8 TMP421_TEMP_LSB
[4] = { 0x10, 0x11, 0x12, 0x13 };
54 #define TMP421_CONFIG_SHUTDOWN 0x40
55 #define TMP421_CONFIG_RANGE 0x04
57 /* Manufacturer / Device ID's */
58 #define TMP421_MANUFACTURER_ID 0x55
59 #define TMP421_DEVICE_ID 0x21
60 #define TMP422_DEVICE_ID 0x22
61 #define TMP423_DEVICE_ID 0x23
63 static const struct i2c_device_id tmp421_id
[] = {
69 MODULE_DEVICE_TABLE(i2c
, tmp421_id
);
72 struct device
*hwmon_dev
;
73 struct mutex update_lock
;
75 unsigned long last_updated
;
81 static int temp_from_s16(s16 reg
)
83 /* Mask out status bits */
84 int temp
= reg
& ~0xf;
86 return (temp
* 1000 + 128) / 256;
89 static int temp_from_u16(u16 reg
)
91 /* Mask out status bits */
92 int temp
= reg
& ~0xf;
94 /* Add offset for extended temperature range. */
97 return (temp
* 1000 + 128) / 256;
100 static struct tmp421_data
*tmp421_update_device(struct device
*dev
)
102 struct i2c_client
*client
= to_i2c_client(dev
);
103 struct tmp421_data
*data
= i2c_get_clientdata(client
);
106 mutex_lock(&data
->update_lock
);
108 if (time_after(jiffies
, data
->last_updated
+ 2 * HZ
) || !data
->valid
) {
109 data
->config
= i2c_smbus_read_byte_data(client
,
110 TMP421_CONFIG_REG_1
);
112 for (i
= 0; i
< data
->channels
; i
++) {
113 data
->temp
[i
] = i2c_smbus_read_byte_data(client
,
114 TMP421_TEMP_MSB
[i
]) << 8;
115 data
->temp
[i
] |= i2c_smbus_read_byte_data(client
,
118 data
->last_updated
= jiffies
;
122 mutex_unlock(&data
->update_lock
);
127 static ssize_t
show_temp_value(struct device
*dev
,
128 struct device_attribute
*devattr
, char *buf
)
130 int index
= to_sensor_dev_attr(devattr
)->index
;
131 struct tmp421_data
*data
= tmp421_update_device(dev
);
134 mutex_lock(&data
->update_lock
);
135 if (data
->config
& TMP421_CONFIG_RANGE
)
136 temp
= temp_from_u16(data
->temp
[index
]);
138 temp
= temp_from_s16(data
->temp
[index
]);
139 mutex_unlock(&data
->update_lock
);
141 return sprintf(buf
, "%d\n", temp
);
144 static ssize_t
show_fault(struct device
*dev
,
145 struct device_attribute
*devattr
, char *buf
)
147 int index
= to_sensor_dev_attr(devattr
)->index
;
148 struct tmp421_data
*data
= tmp421_update_device(dev
);
151 * The OPEN bit signals a fault. This is bit 0 of the temperature
152 * register (low byte).
154 if (data
->temp
[index
] & 0x01)
155 return sprintf(buf
, "1\n");
157 return sprintf(buf
, "0\n");
160 static mode_t
tmp421_is_visible(struct kobject
*kobj
, struct attribute
*a
,
163 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
164 struct tmp421_data
*data
= dev_get_drvdata(dev
);
165 struct device_attribute
*devattr
;
168 devattr
= container_of(a
, struct device_attribute
, attr
);
169 index
= to_sensor_dev_attr(devattr
)->index
;
171 if (index
< data
->channels
)
177 static SENSOR_DEVICE_ATTR(temp1_input
, S_IRUGO
, show_temp_value
, NULL
, 0);
178 static SENSOR_DEVICE_ATTR(temp2_input
, S_IRUGO
, show_temp_value
, NULL
, 1);
179 static SENSOR_DEVICE_ATTR(temp2_fault
, S_IRUGO
, show_fault
, NULL
, 1);
180 static SENSOR_DEVICE_ATTR(temp3_input
, S_IRUGO
, show_temp_value
, NULL
, 2);
181 static SENSOR_DEVICE_ATTR(temp3_fault
, S_IRUGO
, show_fault
, NULL
, 2);
182 static SENSOR_DEVICE_ATTR(temp4_input
, S_IRUGO
, show_temp_value
, NULL
, 3);
183 static SENSOR_DEVICE_ATTR(temp4_fault
, S_IRUGO
, show_fault
, NULL
, 3);
185 static struct attribute
*tmp421_attr
[] = {
186 &sensor_dev_attr_temp1_input
.dev_attr
.attr
,
187 &sensor_dev_attr_temp2_input
.dev_attr
.attr
,
188 &sensor_dev_attr_temp2_fault
.dev_attr
.attr
,
189 &sensor_dev_attr_temp3_input
.dev_attr
.attr
,
190 &sensor_dev_attr_temp3_fault
.dev_attr
.attr
,
191 &sensor_dev_attr_temp4_input
.dev_attr
.attr
,
192 &sensor_dev_attr_temp4_fault
.dev_attr
.attr
,
196 static const struct attribute_group tmp421_group
= {
197 .attrs
= tmp421_attr
,
198 .is_visible
= tmp421_is_visible
,
201 static int tmp421_init_client(struct i2c_client
*client
)
203 int config
, config_orig
;
205 /* Set the conversion rate to 2 Hz */
206 i2c_smbus_write_byte_data(client
, TMP421_CONVERSION_RATE_REG
, 0x05);
208 /* Start conversions (disable shutdown if necessary) */
209 config
= i2c_smbus_read_byte_data(client
, TMP421_CONFIG_REG_1
);
211 dev_err(&client
->dev
, "Could not read configuration"
212 " register (%d)\n", config
);
216 config_orig
= config
;
217 config
&= ~TMP421_CONFIG_SHUTDOWN
;
219 if (config
!= config_orig
) {
220 dev_info(&client
->dev
, "Enable monitoring chip\n");
221 i2c_smbus_write_byte_data(client
, TMP421_CONFIG_REG_1
, config
);
227 static int tmp421_detect(struct i2c_client
*client
,
228 struct i2c_board_info
*info
)
231 struct i2c_adapter
*adapter
= client
->adapter
;
232 const char *names
[] = { "TMP421", "TMP422", "TMP423" };
235 if (!i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_BYTE_DATA
))
238 reg
= i2c_smbus_read_byte_data(client
, TMP421_MANUFACTURER_ID_REG
);
239 if (reg
!= TMP421_MANUFACTURER_ID
)
242 reg
= i2c_smbus_read_byte_data(client
, TMP421_DEVICE_ID_REG
);
244 case TMP421_DEVICE_ID
:
247 case TMP422_DEVICE_ID
:
250 case TMP423_DEVICE_ID
:
257 strlcpy(info
->type
, tmp421_id
[kind
].name
, I2C_NAME_SIZE
);
258 dev_info(&adapter
->dev
, "Detected TI %s chip at 0x%02x\n",
259 names
[kind
], client
->addr
);
264 static int tmp421_probe(struct i2c_client
*client
,
265 const struct i2c_device_id
*id
)
267 struct tmp421_data
*data
;
270 data
= kzalloc(sizeof(struct tmp421_data
), GFP_KERNEL
);
274 i2c_set_clientdata(client
, data
);
275 mutex_init(&data
->update_lock
);
276 data
->channels
= id
->driver_data
;
278 err
= tmp421_init_client(client
);
282 err
= sysfs_create_group(&client
->dev
.kobj
, &tmp421_group
);
286 data
->hwmon_dev
= hwmon_device_register(&client
->dev
);
287 if (IS_ERR(data
->hwmon_dev
)) {
288 err
= PTR_ERR(data
->hwmon_dev
);
289 data
->hwmon_dev
= NULL
;
295 sysfs_remove_group(&client
->dev
.kobj
, &tmp421_group
);
303 static int tmp421_remove(struct i2c_client
*client
)
305 struct tmp421_data
*data
= i2c_get_clientdata(client
);
307 hwmon_device_unregister(data
->hwmon_dev
);
308 sysfs_remove_group(&client
->dev
.kobj
, &tmp421_group
);
315 static struct i2c_driver tmp421_driver
= {
316 .class = I2C_CLASS_HWMON
,
320 .probe
= tmp421_probe
,
321 .remove
= tmp421_remove
,
322 .id_table
= tmp421_id
,
323 .detect
= tmp421_detect
,
324 .address_list
= normal_i2c
,
327 static int __init
tmp421_init(void)
329 return i2c_add_driver(&tmp421_driver
);
332 static void __exit
tmp421_exit(void)
334 i2c_del_driver(&tmp421_driver
);
337 MODULE_AUTHOR("Andre Prendel <andre.prendel@gmx.de>");
338 MODULE_DESCRIPTION("Texas Instruments TMP421/422/423 temperature sensor"
340 MODULE_LICENSE("GPL");
342 module_init(tmp421_init
);
343 module_exit(tmp421_exit
);