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/i2c.h>
28 #include <linux/i2c-sensor.h>
31 /* Addresses to scan */
32 static unsigned short normal_i2c[] = { I2C_CLIENT_END };
33 static unsigned short normal_i2c_range[] = { 0x48, 0x4f, I2C_CLIENT_END };
34 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
35 static unsigned int normal_isa_range[] = { I2C_CLIENT_ISA_END };
37 /* Insmod parameters */
38 SENSORS_INSMOD_1(ds1621);
39 static int polarity = -1;
40 MODULE_PARM(polarity, "i");
41 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
43 /* Many DS1621 constants specified below */
44 /* Config register used for detection */
46 /* |Done|THF |TLF |NVB | 1 | 0 |POL |1SHOT| */
47 #define DS1621_REG_CONFIG_MASK 0x0C
48 #define DS1621_REG_CONFIG_VAL 0x08
49 #define DS1621_REG_CONFIG_POLARITY 0x02
50 #define DS1621_REG_CONFIG_1SHOT 0x01
51 #define DS1621_REG_CONFIG_DONE 0x80
53 /* The DS1621 registers */
54 #define DS1621_REG_TEMP 0xAA /* word, RO */
55 #define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */
56 #define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */
57 #define DS1621_REG_CONF 0xAC /* byte, RW */
58 #define DS1621_COM_START 0xEE /* no data */
60 /* The DS1621 configuration register */
61 #define DS1621_ALARM_TEMP_HIGH 0x40
62 #define DS1621_ALARM_TEMP_LOW 0x20
64 /* Conversions. Rounding and limit checking is only done on the TO_REG
65 variants. Note that you should be a bit careful with which arguments
66 these macros are called: arguments may be evaluated more than once.
67 Fixing this is just not worth it. */
68 #define ALARMS_FROM_REG(val) ((val) & \
69 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
71 /* Each client has this additional data */
73 struct i2c_client client;
74 struct semaphore 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 = {
93 .id = I2C_DRIVERID_DS1621,
94 .flags = I2C_DF_NOTIFY,
95 .attach_adapter = ds1621_attach_adapter,
96 .detach_client = ds1621_detach_client,
99 static int ds1621_id = 0;
101 /* All registers are word-sized, except for the configuration register.
102 DS1621 uses a high-byte first convention, which is exactly opposite to
103 the usual practice. */
104 static int ds1621_read_value(struct i2c_client *client, u8 reg)
106 if (reg == DS1621_REG_CONF)
107 return i2c_smbus_read_byte_data(client, reg);
109 return swab16(i2c_smbus_read_word_data(client, reg));
112 /* All registers are word-sized, except for the configuration register.
113 DS1621 uses a high-byte first convention, which is exactly opposite to
114 the usual practice. */
115 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
117 if (reg == DS1621_REG_CONF)
118 return i2c_smbus_write_byte_data(client, reg, value);
120 return i2c_smbus_write_word_data(client, reg, swab16(value));
123 static void ds1621_init_client(struct i2c_client *client)
125 int reg = ds1621_read_value(client, DS1621_REG_CONF);
126 /* switch to continous conversion mode */
127 reg &= ~ DS1621_REG_CONFIG_1SHOT;
129 /* setup output polarity */
131 reg &= ~DS1621_REG_CONFIG_POLARITY;
132 else if (polarity == 1)
133 reg |= DS1621_REG_CONFIG_POLARITY;
135 ds1621_write_value(client, DS1621_REG_CONF, reg);
137 /* start conversion */
138 i2c_smbus_write_byte(client, DS1621_COM_START);
141 #define show(value) \
142 static ssize_t show_##value(struct device *dev, char *buf) \
144 struct ds1621_data *data = ds1621_update_client(dev); \
145 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
152 #define set_temp(suffix, value, reg) \
153 static ssize_t set_temp_##suffix(struct device *dev, const char *buf, \
156 struct i2c_client *client = to_i2c_client(dev); \
157 struct ds1621_data *data = ds1621_update_client(dev); \
158 data->value = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
159 ds1621_write_value(client, reg, data->value); \
163 set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
164 set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
166 static ssize_t show_alarms(struct device *dev, char *buf)
168 struct ds1621_data *data = ds1621_update_client(dev);
169 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
172 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
173 static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
174 static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min);
175 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
178 static int ds1621_attach_adapter(struct i2c_adapter *adapter)
180 return i2c_detect(adapter, &addr_data, ds1621_detect);
183 /* This function is called by i2c_detect */
184 int ds1621_detect(struct i2c_adapter *adapter, int address,
188 struct i2c_client *new_client;
189 struct ds1621_data *data;
192 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
193 | I2C_FUNC_SMBUS_WORD_DATA
194 | I2C_FUNC_SMBUS_WRITE_BYTE))
197 /* OK. For now, we presume we have a valid client. We now create the
198 client structure, even though we cannot fill it completely yet.
199 But it allows us to access ds1621_{read,write}_value. */
200 if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
204 memset(data, 0, sizeof(struct ds1621_data));
206 new_client = &data->client;
207 i2c_set_clientdata(new_client, data);
208 new_client->addr = address;
209 new_client->adapter = adapter;
210 new_client->driver = &ds1621_driver;
211 new_client->flags = 0;
214 /* Now, we do the remaining detection. It is lousy. */
216 conf = ds1621_read_value(new_client, DS1621_REG_CONF);
217 if ((conf & DS1621_REG_CONFIG_MASK) != DS1621_REG_CONFIG_VAL)
219 temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
222 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
225 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
230 /* Determine the chip type - only one kind supported! */
234 /* Fill in remaining client fields and put it into the global list */
235 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE);
237 new_client->id = ds1621_id++;
239 init_MUTEX(&data->update_lock);
241 /* Tell the I2C layer a new client has arrived */
242 if ((err = i2c_attach_client(new_client)))
245 /* Initialize the DS1621 chip */
246 ds1621_init_client(new_client);
248 /* Register sysfs hooks */
249 device_create_file(&new_client->dev, &dev_attr_alarms);
250 device_create_file(&new_client->dev, &dev_attr_temp1_input);
251 device_create_file(&new_client->dev, &dev_attr_temp1_min);
252 device_create_file(&new_client->dev, &dev_attr_temp1_max);
256 /* OK, this is not exactly good programming practice, usually. But it is
257 very code-efficient in this case. */
264 static int ds1621_detach_client(struct i2c_client *client)
268 if ((err = i2c_detach_client(client))) {
269 dev_err(&client->dev, "Client deregistration failed, "
270 "client not detached.\n");
274 kfree(i2c_get_clientdata(client));
280 static struct ds1621_data *ds1621_update_client(struct device *dev)
282 struct i2c_client *client = to_i2c_client(dev);
283 struct ds1621_data *data = i2c_get_clientdata(client);
286 down(&data->update_lock);
288 if ((jiffies - data->last_updated > HZ + HZ / 2) ||
289 (jiffies < data->last_updated) || !data->valid) {
291 dev_dbg(&client->dev, "Starting ds1621 update\n");
293 data->conf = ds1621_read_value(client, DS1621_REG_CONF);
295 data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
297 data->temp_min = ds1621_read_value(client,
298 DS1621_REG_TEMP_MIN);
299 data->temp_max = ds1621_read_value(client,
300 DS1621_REG_TEMP_MAX);
302 /* reset alarms if neccessary */
303 new_conf = data->conf;
304 if (data->temp < data->temp_min)
305 new_conf &= ~DS1621_ALARM_TEMP_LOW;
306 if (data->temp > data->temp_max)
307 new_conf &= ~DS1621_ALARM_TEMP_HIGH;
308 if (data->conf != new_conf)
309 ds1621_write_value(client, DS1621_REG_CONF,
312 data->last_updated = jiffies;
316 up(&data->update_lock);
321 static int __init ds1621_init(void)
323 return i2c_add_driver(&ds1621_driver);
326 static void __exit ds1621_exit(void)
328 i2c_del_driver(&ds1621_driver);
332 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
333 MODULE_DESCRIPTION("DS1621 driver");
334 MODULE_LICENSE("GPL");
336 module_init(ds1621_init);
337 module_exit(ds1621_exit);