2 ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
4 Christian W. Zuckschwerdt <zany@triq.net> 2000-11-23
5 based on lm75.c by Frodo Looijaard <frodol@dds.nl>
6 Ported to Linux 2.6 by Aurelien Jarno <aurelien@aurel32.net> with
7 the help of Jean Delvare <khali@linux-fr.org>
9 This program is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 2 of the License, or
12 (at your option) any later version.
14 This program is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with this program; if not, write to the Free Software
21 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
24 #include <linux/module.h>
25 #include <linux/init.h>
26 #include <linux/slab.h>
27 #include <linux/jiffies.h>
28 #include <linux/i2c.h>
29 #include <linux/hwmon.h>
30 #include <linux/hwmon-sysfs.h>
31 #include <linux/err.h>
32 #include <linux/mutex.h>
33 #include <linux/sysfs.h>
36 /* Addresses to scan */
37 static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
38 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
40 /* Insmod parameters */
41 I2C_CLIENT_INSMOD_1(ds1621);
42 static int polarity = -1;
43 module_param(polarity, int, 0);
44 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
46 /* Many DS1621 constants specified below */
47 /* Config register used for detection */
49 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */
50 #define DS1621_REG_CONFIG_NVB 0x10
51 #define DS1621_REG_CONFIG_POLARITY 0x02
52 #define DS1621_REG_CONFIG_1SHOT 0x01
53 #define DS1621_REG_CONFIG_DONE 0x80
55 /* The DS1621 registers */
56 static const u8 DS1621_REG_TEMP[3] = {
57 0xAA, /* input, word, RO */
58 0xA2, /* min, word, RW */
59 0xA1, /* max, word, RW */
61 #define DS1621_REG_CONF 0xAC /* byte, RW */
62 #define DS1621_COM_START 0xEE /* no data */
63 #define DS1621_COM_STOP 0x22 /* no data */
65 /* The DS1621 configuration register */
66 #define DS1621_ALARM_TEMP_HIGH 0x40
67 #define DS1621_ALARM_TEMP_LOW 0x20
70 #define ALARMS_FROM_REG(val) ((val) & \
71 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
73 /* Each client has this additional data */
75 struct device *hwmon_dev;
76 struct mutex update_lock;
77 char valid; /* !=0 if following fields are valid */
78 unsigned long last_updated; /* In jiffies */
80 u16 temp[3]; /* Register values, word */
81 u8 conf; /* Register encoding, combined */
84 /* Temperature registers are word-sized.
85 DS1621 uses a high-byte first convention, which is exactly opposite to
86 the SMBus standard. */
87 static int ds1621_read_temp(struct i2c_client *client, u8 reg)
91 ret = i2c_smbus_read_word_data(client, reg);
97 static int ds1621_write_temp(struct i2c_client *client, u8 reg, u16 value)
99 return i2c_smbus_write_word_data(client, reg, swab16(value));
102 static void ds1621_init_client(struct i2c_client *client)
104 int reg = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
105 /* switch to continuous conversion mode */
106 reg &= ~ DS1621_REG_CONFIG_1SHOT;
108 /* setup output polarity */
110 reg &= ~DS1621_REG_CONFIG_POLARITY;
111 else if (polarity == 1)
112 reg |= DS1621_REG_CONFIG_POLARITY;
114 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, reg);
116 /* start conversion */
117 i2c_smbus_write_byte(client, DS1621_COM_START);
120 static struct ds1621_data *ds1621_update_client(struct device *dev)
122 struct i2c_client *client = to_i2c_client(dev);
123 struct ds1621_data *data = i2c_get_clientdata(client);
126 mutex_lock(&data->update_lock);
128 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
132 dev_dbg(&client->dev, "Starting ds1621 update\n");
134 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
136 for (i = 0; i < ARRAY_SIZE(data->temp); i++)
137 data->temp[i] = ds1621_read_temp(client,
140 /* reset alarms if necessary */
141 new_conf = data->conf;
142 if (data->temp[0] > data->temp[1]) /* input > min */
143 new_conf &= ~DS1621_ALARM_TEMP_LOW;
144 if (data->temp[0] < data->temp[2]) /* input < max */
145 new_conf &= ~DS1621_ALARM_TEMP_HIGH;
146 if (data->conf != new_conf)
147 i2c_smbus_write_byte_data(client, DS1621_REG_CONF,
150 data->last_updated = jiffies;
154 mutex_unlock(&data->update_lock);
159 static ssize_t show_temp(struct device *dev, struct device_attribute *da,
162 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
163 struct ds1621_data *data = ds1621_update_client(dev);
164 return sprintf(buf, "%d\n",
165 LM75_TEMP_FROM_REG(data->temp[attr->index]));
168 static ssize_t set_temp(struct device *dev, struct device_attribute *da,
169 const char *buf, size_t count)
171 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
172 struct i2c_client *client = to_i2c_client(dev);
173 struct ds1621_data *data = ds1621_update_client(dev);
174 u16 val = LM75_TEMP_TO_REG(simple_strtol(buf, NULL, 10));
176 mutex_lock(&data->update_lock);
177 data->temp[attr->index] = val;
178 ds1621_write_temp(client, DS1621_REG_TEMP[attr->index],
179 data->temp[attr->index]);
180 mutex_unlock(&data->update_lock);
184 static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
187 struct ds1621_data *data = ds1621_update_client(dev);
188 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
191 static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
194 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
195 struct ds1621_data *data = ds1621_update_client(dev);
196 return sprintf(buf, "%d\n", !!(data->conf & attr->index));
199 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
200 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
201 static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
202 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
203 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
204 DS1621_ALARM_TEMP_LOW);
205 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
206 DS1621_ALARM_TEMP_HIGH);
208 static struct attribute *ds1621_attributes[] = {
209 &sensor_dev_attr_temp1_input.dev_attr.attr,
210 &sensor_dev_attr_temp1_min.dev_attr.attr,
211 &sensor_dev_attr_temp1_max.dev_attr.attr,
212 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
213 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
214 &dev_attr_alarms.attr,
218 static const struct attribute_group ds1621_group = {
219 .attrs = ds1621_attributes,
223 /* Return 0 if detection is successful, -ENODEV otherwise */
224 static int ds1621_detect(struct i2c_client *client, int kind,
225 struct i2c_board_info *info)
227 struct i2c_adapter *adapter = client->adapter;
231 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
232 | I2C_FUNC_SMBUS_WORD_DATA
233 | I2C_FUNC_SMBUS_WRITE_BYTE))
236 /* Now, we do the remaining detection. It is lousy. */
238 /* The NVB bit should be low if no EEPROM write has been
239 requested during the latest 10ms, which is highly
240 improbable in our case. */
241 conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
242 if (conf < 0 || conf & DS1621_REG_CONFIG_NVB)
244 /* The 7 lowest bits of a temperature should always be 0. */
245 for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) {
246 temp = i2c_smbus_read_word_data(client,
248 if (temp < 0 || (temp & 0x7f00))
253 strlcpy(info->type, "ds1621", I2C_NAME_SIZE);
258 static int ds1621_probe(struct i2c_client *client,
259 const struct i2c_device_id *id)
261 struct ds1621_data *data;
264 data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL);
270 i2c_set_clientdata(client, data);
271 mutex_init(&data->update_lock);
273 /* Initialize the DS1621 chip */
274 ds1621_init_client(client);
276 /* Register sysfs hooks */
277 if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group)))
280 data->hwmon_dev = hwmon_device_register(&client->dev);
281 if (IS_ERR(data->hwmon_dev)) {
282 err = PTR_ERR(data->hwmon_dev);
283 goto exit_remove_files;
289 sysfs_remove_group(&client->dev.kobj, &ds1621_group);
296 static int ds1621_remove(struct i2c_client *client)
298 struct ds1621_data *data = i2c_get_clientdata(client);
300 hwmon_device_unregister(data->hwmon_dev);
301 sysfs_remove_group(&client->dev.kobj, &ds1621_group);
308 static const struct i2c_device_id ds1621_id[] = {
309 { "ds1621", ds1621 },
310 { "ds1625", ds1621 },
313 MODULE_DEVICE_TABLE(i2c, ds1621_id);
315 /* This is the driver that will be inserted */
316 static struct i2c_driver ds1621_driver = {
317 .class = I2C_CLASS_HWMON,
321 .probe = ds1621_probe,
322 .remove = ds1621_remove,
323 .id_table = ds1621_id,
324 .detect = ds1621_detect,
325 .address_data = &addr_data,
328 static int __init ds1621_init(void)
330 return i2c_add_driver(&ds1621_driver);
333 static void __exit ds1621_exit(void)
335 i2c_del_driver(&ds1621_driver);
339 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
340 MODULE_DESCRIPTION("DS1621 driver");
341 MODULE_LICENSE("GPL");
343 module_init(ds1621_init);
344 module_exit(ds1621_exit);