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/err.h>
31 #include <linux/mutex.h>
32 #include <linux/sysfs.h>
35 /* Addresses to scan */
36 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
37 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
39 /* Insmod parameters */
40 I2C_CLIENT_INSMOD_1(ds1621);
41 static int polarity = -1;
42 module_param(polarity, int, 0);
43 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
45 /* Many DS1621 constants specified below */
46 /* Config register used for detection */
48 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */
49 #define DS1621_REG_CONFIG_NVB 0x10
50 #define DS1621_REG_CONFIG_POLARITY 0x02
51 #define DS1621_REG_CONFIG_1SHOT 0x01
52 #define DS1621_REG_CONFIG_DONE 0x80
54 /* The DS1621 registers */
55 #define DS1621_REG_TEMP 0xAA /* word, RO */
56 #define DS1621_REG_TEMP_MIN 0xA2 /* word, RW */
57 #define DS1621_REG_TEMP_MAX 0xA1 /* word, RW */
58 #define DS1621_REG_CONF 0xAC /* byte, RW */
59 #define DS1621_COM_START 0xEE /* no data */
60 #define DS1621_COM_STOP 0x22 /* no data */
62 /* The DS1621 configuration register */
63 #define DS1621_ALARM_TEMP_HIGH 0x40
64 #define DS1621_ALARM_TEMP_LOW 0x20
67 #define ALARMS_FROM_REG(val) ((val) & \
68 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
70 /* Each client has this additional data */
72 struct i2c_client client;
73 struct class_device *class_dev;
74 struct mutex update_lock;
75 char valid; /* !=0 if following fields are valid */
76 unsigned long last_updated; /* In jiffies */
78 u16 temp, temp_min, temp_max; /* Register values, word */
79 u8 conf; /* Register encoding, combined */
82 static int ds1621_attach_adapter(struct i2c_adapter *adapter);
83 static int ds1621_detect(struct i2c_adapter *adapter, int address,
85 static void ds1621_init_client(struct i2c_client *client);
86 static int ds1621_detach_client(struct i2c_client *client);
87 static struct ds1621_data *ds1621_update_client(struct device *dev);
89 /* This is the driver that will be inserted */
90 static struct i2c_driver ds1621_driver = {
94 .id = I2C_DRIVERID_DS1621,
95 .attach_adapter = ds1621_attach_adapter,
96 .detach_client = ds1621_detach_client,
99 /* All registers are word-sized, except for the configuration register.
100 DS1621 uses a high-byte first convention, which is exactly opposite to
101 the SMBus standard. */
102 static int ds1621_read_value(struct i2c_client *client, u8 reg)
104 if (reg == DS1621_REG_CONF)
105 return i2c_smbus_read_byte_data(client, reg);
107 return swab16(i2c_smbus_read_word_data(client, reg));
110 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
112 if (reg == DS1621_REG_CONF)
113 return i2c_smbus_write_byte_data(client, reg, value);
115 return i2c_smbus_write_word_data(client, reg, swab16(value));
118 static void ds1621_init_client(struct i2c_client *client)
120 int reg = ds1621_read_value(client, DS1621_REG_CONF);
121 /* switch to continuous conversion mode */
122 reg &= ~ DS1621_REG_CONFIG_1SHOT;
124 /* setup output polarity */
126 reg &= ~DS1621_REG_CONFIG_POLARITY;
127 else if (polarity == 1)
128 reg |= DS1621_REG_CONFIG_POLARITY;
130 ds1621_write_value(client, DS1621_REG_CONF, reg);
132 /* start conversion */
133 i2c_smbus_write_byte(client, DS1621_COM_START);
136 #define show(value) \
137 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
139 struct ds1621_data *data = ds1621_update_client(dev); \
140 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
147 #define set_temp(suffix, value, reg) \
148 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
151 struct i2c_client *client = to_i2c_client(dev); \
152 struct ds1621_data *data = ds1621_update_client(dev); \
153 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
155 mutex_lock(&data->update_lock); \
157 ds1621_write_value(client, reg, data->value); \
158 mutex_unlock(&data->update_lock); \
162 set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
163 set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
165 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
167 struct ds1621_data *data = ds1621_update_client(dev);
168 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
171 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
172 static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
173 static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min);
174 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
176 static struct attribute *ds1621_attributes[] = {
177 &dev_attr_temp1_input.attr,
178 &dev_attr_temp1_min.attr,
179 &dev_attr_temp1_max.attr,
180 &dev_attr_alarms.attr,
184 static const struct attribute_group ds1621_group = {
185 .attrs = ds1621_attributes,
189 static int ds1621_attach_adapter(struct i2c_adapter *adapter)
191 if (!(adapter->class & I2C_CLASS_HWMON))
193 return i2c_probe(adapter, &addr_data, ds1621_detect);
196 /* This function is called by i2c_probe */
197 static int ds1621_detect(struct i2c_adapter *adapter, int address,
201 struct i2c_client *client;
202 struct ds1621_data *data;
205 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
206 | I2C_FUNC_SMBUS_WORD_DATA
207 | I2C_FUNC_SMBUS_WRITE_BYTE))
210 /* OK. For now, we presume we have a valid client. We now create the
211 client structure, even though we cannot fill it completely yet.
212 But it allows us to access ds1621_{read,write}_value. */
213 if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
218 client = &data->client;
219 i2c_set_clientdata(client, data);
220 client->addr = address;
221 client->adapter = adapter;
222 client->driver = &ds1621_driver;
224 /* Now, we do the remaining detection. It is lousy. */
226 /* The NVB bit should be low if no EEPROM write has been
227 requested during the latest 10ms, which is highly
228 improbable in our case. */
229 conf = ds1621_read_value(client, DS1621_REG_CONF);
230 if (conf & DS1621_REG_CONFIG_NVB)
232 /* The 7 lowest bits of a temperature should always be 0. */
233 temp = ds1621_read_value(client, DS1621_REG_TEMP);
236 temp = ds1621_read_value(client, DS1621_REG_TEMP_MIN);
239 temp = ds1621_read_value(client, DS1621_REG_TEMP_MAX);
244 /* Fill in remaining client fields and put it into the global list */
245 strlcpy(client->name, "ds1621", I2C_NAME_SIZE);
246 mutex_init(&data->update_lock);
248 /* Tell the I2C layer a new client has arrived */
249 if ((err = i2c_attach_client(client)))
252 /* Initialize the DS1621 chip */
253 ds1621_init_client(client);
255 /* Register sysfs hooks */
256 if ((err = sysfs_create_group(&client->dev.kobj, &ds1621_group)))
259 data->class_dev = hwmon_device_register(&client->dev);
260 if (IS_ERR(data->class_dev)) {
261 err = PTR_ERR(data->class_dev);
262 goto exit_remove_files;
268 sysfs_remove_group(&client->dev.kobj, &ds1621_group);
270 i2c_detach_client(client);
277 static int ds1621_detach_client(struct i2c_client *client)
279 struct ds1621_data *data = i2c_get_clientdata(client);
282 hwmon_device_unregister(data->class_dev);
283 sysfs_remove_group(&client->dev.kobj, &ds1621_group);
285 if ((err = i2c_detach_client(client)))
294 static struct ds1621_data *ds1621_update_client(struct device *dev)
296 struct i2c_client *client = to_i2c_client(dev);
297 struct ds1621_data *data = i2c_get_clientdata(client);
300 mutex_lock(&data->update_lock);
302 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
305 dev_dbg(&client->dev, "Starting ds1621 update\n");
307 data->conf = ds1621_read_value(client, DS1621_REG_CONF);
309 data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
311 data->temp_min = ds1621_read_value(client,
312 DS1621_REG_TEMP_MIN);
313 data->temp_max = ds1621_read_value(client,
314 DS1621_REG_TEMP_MAX);
316 /* reset alarms if necessary */
317 new_conf = data->conf;
318 if (data->temp > data->temp_min)
319 new_conf &= ~DS1621_ALARM_TEMP_LOW;
320 if (data->temp < data->temp_max)
321 new_conf &= ~DS1621_ALARM_TEMP_HIGH;
322 if (data->conf != new_conf)
323 ds1621_write_value(client, DS1621_REG_CONF,
326 data->last_updated = jiffies;
330 mutex_unlock(&data->update_lock);
335 static int __init ds1621_init(void)
337 return i2c_add_driver(&ds1621_driver);
340 static void __exit ds1621_exit(void)
342 i2c_del_driver(&ds1621_driver);
346 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
347 MODULE_DESCRIPTION("DS1621 driver");
348 MODULE_LICENSE("GPL");
350 module_init(ds1621_init);
351 module_exit(ds1621_exit);