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/i2c-sensor.h>
30 #include <linux/hwmon.h>
31 #include <linux/err.h>
34 /* Addresses to scan */
35 static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
36 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
37 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
39 /* Insmod parameters */
40 SENSORS_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 0xA1 /* word, RW */
57 #define DS1621_REG_TEMP_MAX 0xA2 /* 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
66 /* Conversions. Rounding and limit checking is only done on the TO_REG
67 variants. Note that you should be a bit careful with which arguments
68 these macros are called: arguments may be evaluated more than once.
69 Fixing this is just not worth it. */
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 i2c_client client;
76 struct class_device *class_dev;
77 struct semaphore update_lock;
78 char valid; /* !=0 if following fields are valid */
79 unsigned long last_updated; /* In jiffies */
81 u16 temp, temp_min, temp_max; /* Register values, word */
82 u8 conf; /* Register encoding, combined */
85 static int ds1621_attach_adapter(struct i2c_adapter *adapter);
86 static int ds1621_detect(struct i2c_adapter *adapter, int address,
88 static void ds1621_init_client(struct i2c_client *client);
89 static int ds1621_detach_client(struct i2c_client *client);
90 static struct ds1621_data *ds1621_update_client(struct device *dev);
92 /* This is the driver that will be inserted */
93 static struct i2c_driver ds1621_driver = {
96 .id = I2C_DRIVERID_DS1621,
97 .flags = I2C_DF_NOTIFY,
98 .attach_adapter = ds1621_attach_adapter,
99 .detach_client = ds1621_detach_client,
102 /* All registers are word-sized, except for the configuration register.
103 DS1621 uses a high-byte first convention, which is exactly opposite to
104 the usual practice. */
105 static int ds1621_read_value(struct i2c_client *client, u8 reg)
107 if (reg == DS1621_REG_CONF)
108 return i2c_smbus_read_byte_data(client, reg);
110 return swab16(i2c_smbus_read_word_data(client, reg));
113 /* All registers are word-sized, except for the configuration register.
114 DS1621 uses a high-byte first convention, which is exactly opposite to
115 the usual practice. */
116 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
118 if (reg == DS1621_REG_CONF)
119 return i2c_smbus_write_byte_data(client, reg, value);
121 return i2c_smbus_write_word_data(client, reg, swab16(value));
124 static void ds1621_init_client(struct i2c_client *client)
126 int reg = ds1621_read_value(client, DS1621_REG_CONF);
127 /* switch to continuous conversion mode */
128 reg &= ~ DS1621_REG_CONFIG_1SHOT;
130 /* setup output polarity */
132 reg &= ~DS1621_REG_CONFIG_POLARITY;
133 else if (polarity == 1)
134 reg |= DS1621_REG_CONFIG_POLARITY;
136 ds1621_write_value(client, DS1621_REG_CONF, reg);
138 /* start conversion */
139 i2c_smbus_write_byte(client, DS1621_COM_START);
142 #define show(value) \
143 static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
145 struct ds1621_data *data = ds1621_update_client(dev); \
146 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
153 #define set_temp(suffix, value, reg) \
154 static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
157 struct i2c_client *client = to_i2c_client(dev); \
158 struct ds1621_data *data = ds1621_update_client(dev); \
159 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
161 down(&data->update_lock); \
163 ds1621_write_value(client, reg, data->value); \
164 up(&data->update_lock); \
168 set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
169 set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
171 static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
173 struct ds1621_data *data = ds1621_update_client(dev);
174 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
177 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
178 static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
179 static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min);
180 static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
183 static int ds1621_attach_adapter(struct i2c_adapter *adapter)
185 return i2c_detect(adapter, &addr_data, ds1621_detect);
188 /* This function is called by i2c_detect */
189 int ds1621_detect(struct i2c_adapter *adapter, int address,
193 struct i2c_client *new_client;
194 struct ds1621_data *data;
197 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
198 | I2C_FUNC_SMBUS_WORD_DATA
199 | I2C_FUNC_SMBUS_WRITE_BYTE))
202 /* OK. For now, we presume we have a valid client. We now create the
203 client structure, even though we cannot fill it completely yet.
204 But it allows us to access ds1621_{read,write}_value. */
205 if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
209 memset(data, 0, sizeof(struct ds1621_data));
211 new_client = &data->client;
212 i2c_set_clientdata(new_client, data);
213 new_client->addr = address;
214 new_client->adapter = adapter;
215 new_client->driver = &ds1621_driver;
216 new_client->flags = 0;
219 /* Now, we do the remaining detection. It is lousy. */
221 /* The NVB bit should be low if no EEPROM write has been
222 requested during the latest 10ms, which is highly
223 improbable in our case. */
224 conf = ds1621_read_value(new_client, DS1621_REG_CONF);
225 if (conf & DS1621_REG_CONFIG_NVB)
227 /* The 7 lowest bits of a temperature should always be 0. */
228 temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
231 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
234 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
239 /* Determine the chip type - only one kind supported! */
243 /* Fill in remaining client fields and put it into the global list */
244 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE);
246 init_MUTEX(&data->update_lock);
248 /* Tell the I2C layer a new client has arrived */
249 if ((err = i2c_attach_client(new_client)))
252 /* Initialize the DS1621 chip */
253 ds1621_init_client(new_client);
255 /* Register sysfs hooks */
256 data->class_dev = hwmon_device_register(&new_client->dev);
257 if (IS_ERR(data->class_dev)) {
258 err = PTR_ERR(data->class_dev);
262 device_create_file(&new_client->dev, &dev_attr_alarms);
263 device_create_file(&new_client->dev, &dev_attr_temp1_input);
264 device_create_file(&new_client->dev, &dev_attr_temp1_min);
265 device_create_file(&new_client->dev, &dev_attr_temp1_max);
269 /* OK, this is not exactly good programming practice, usually. But it is
270 very code-efficient in this case. */
272 i2c_detach_client(new_client);
279 static int ds1621_detach_client(struct i2c_client *client)
281 struct ds1621_data *data = i2c_get_clientdata(client);
284 hwmon_device_unregister(data->class_dev);
286 if ((err = i2c_detach_client(client))) {
287 dev_err(&client->dev, "Client deregistration failed, "
288 "client not detached.\n");
298 static struct ds1621_data *ds1621_update_client(struct device *dev)
300 struct i2c_client *client = to_i2c_client(dev);
301 struct ds1621_data *data = i2c_get_clientdata(client);
304 down(&data->update_lock);
306 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
309 dev_dbg(&client->dev, "Starting ds1621 update\n");
311 data->conf = ds1621_read_value(client, DS1621_REG_CONF);
313 data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
315 data->temp_min = ds1621_read_value(client,
316 DS1621_REG_TEMP_MIN);
317 data->temp_max = ds1621_read_value(client,
318 DS1621_REG_TEMP_MAX);
320 /* reset alarms if necessary */
321 new_conf = data->conf;
322 if (data->temp < data->temp_min)
323 new_conf &= ~DS1621_ALARM_TEMP_LOW;
324 if (data->temp > data->temp_max)
325 new_conf &= ~DS1621_ALARM_TEMP_HIGH;
326 if (data->conf != new_conf)
327 ds1621_write_value(client, DS1621_REG_CONF,
330 data->last_updated = jiffies;
334 up(&data->update_lock);
339 static int __init ds1621_init(void)
341 return i2c_add_driver(&ds1621_driver);
344 static void __exit ds1621_exit(void)
346 i2c_del_driver(&ds1621_driver);
350 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
351 MODULE_DESCRIPTION("DS1621 driver");
352 MODULE_LICENSE("GPL");
354 module_init(ds1621_init);
355 module_exit(ds1621_exit);