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[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
33 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
34 static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
36 /* Insmod parameters */
37 SENSORS_INSMOD_1(ds1621);
38 static int polarity = -1;
39 module_param(polarity, int, 0);
40 MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
42 /* Many DS1621 constants specified below */
43 /* Config register used for detection */
45 /* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */
46 #define DS1621_REG_CONFIG_NVB 0x10
47 #define DS1621_REG_CONFIG_POLARITY 0x02
48 #define DS1621_REG_CONFIG_1SHOT 0x01
49 #define DS1621_REG_CONFIG_DONE 0x80
51 /* The DS1621 registers */
52 #define DS1621_REG_TEMP 0xAA /* word, RO */
53 #define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */
54 #define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */
55 #define DS1621_REG_CONF 0xAC /* byte, RW */
56 #define DS1621_COM_START 0xEE /* no data */
57 #define DS1621_COM_STOP 0x22 /* no data */
59 /* The DS1621 configuration register */
60 #define DS1621_ALARM_TEMP_HIGH 0x40
61 #define DS1621_ALARM_TEMP_LOW 0x20
63 /* Conversions. Rounding and limit checking is only done on the TO_REG
64 variants. Note that you should be a bit careful with which arguments
65 these macros are called: arguments may be evaluated more than once.
66 Fixing this is just not worth it. */
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 semaphore update_lock;
74 char valid; /* !=0 if following fields are valid */
75 unsigned long last_updated; /* In jiffies */
77 u16 temp, temp_min, temp_max; /* Register values, word */
78 u8 conf; /* Register encoding, combined */
81 static int ds1621_attach_adapter(struct i2c_adapter *adapter);
82 static int ds1621_detect(struct i2c_adapter *adapter, int address,
84 static void ds1621_init_client(struct i2c_client *client);
85 static int ds1621_detach_client(struct i2c_client *client);
86 static struct ds1621_data *ds1621_update_client(struct device *dev);
88 /* This is the driver that will be inserted */
89 static struct i2c_driver ds1621_driver = {
92 .id = I2C_DRIVERID_DS1621,
93 .flags = I2C_DF_NOTIFY,
94 .attach_adapter = ds1621_attach_adapter,
95 .detach_client = ds1621_detach_client,
100 /* All registers are word-sized, except for the configuration register.
101 DS1621 uses a high-byte first convention, which is exactly opposite to
102 the usual practice. */
103 static int ds1621_read_value(struct i2c_client *client, u8 reg)
105 if (reg == DS1621_REG_CONF)
106 return i2c_smbus_read_byte_data(client, reg);
108 return swab16(i2c_smbus_read_word_data(client, reg));
111 /* All registers are word-sized, except for the configuration register.
112 DS1621 uses a high-byte first convention, which is exactly opposite to
113 the usual practice. */
114 static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
116 if (reg == DS1621_REG_CONF)
117 return i2c_smbus_write_byte_data(client, reg, value);
119 return i2c_smbus_write_word_data(client, reg, swab16(value));
122 static void ds1621_init_client(struct i2c_client *client)
124 int reg = ds1621_read_value(client, DS1621_REG_CONF);
125 /* switch to continous conversion mode */
126 reg &= ~ DS1621_REG_CONFIG_1SHOT;
128 /* setup output polarity */
130 reg &= ~DS1621_REG_CONFIG_POLARITY;
131 else if (polarity == 1)
132 reg |= DS1621_REG_CONFIG_POLARITY;
134 ds1621_write_value(client, DS1621_REG_CONF, reg);
136 /* start conversion */
137 i2c_smbus_write_byte(client, DS1621_COM_START);
140 #define show(value) \
141 static ssize_t show_##value(struct device *dev, char *buf) \
143 struct ds1621_data *data = ds1621_update_client(dev); \
144 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
151 #define set_temp(suffix, value, reg) \
152 static ssize_t set_temp_##suffix(struct device *dev, const char *buf, \
155 struct i2c_client *client = to_i2c_client(dev); \
156 struct ds1621_data *data = ds1621_update_client(dev); \
157 data->value = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
158 ds1621_write_value(client, reg, data->value); \
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, 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);
177 static int ds1621_attach_adapter(struct i2c_adapter *adapter)
179 return i2c_detect(adapter, &addr_data, ds1621_detect);
182 /* This function is called by i2c_detect */
183 int ds1621_detect(struct i2c_adapter *adapter, int address,
187 struct i2c_client *new_client;
188 struct ds1621_data *data;
191 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
192 | I2C_FUNC_SMBUS_WORD_DATA
193 | I2C_FUNC_SMBUS_WRITE_BYTE))
196 /* OK. For now, we presume we have a valid client. We now create the
197 client structure, even though we cannot fill it completely yet.
198 But it allows us to access ds1621_{read,write}_value. */
199 if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
203 memset(data, 0, sizeof(struct ds1621_data));
205 new_client = &data->client;
206 i2c_set_clientdata(new_client, data);
207 new_client->addr = address;
208 new_client->adapter = adapter;
209 new_client->driver = &ds1621_driver;
210 new_client->flags = 0;
213 /* Now, we do the remaining detection. It is lousy. */
215 /* The NVB bit should be low if no EEPROM write has been
216 requested during the latest 10ms, which is highly
217 improbable in our case. */
218 conf = ds1621_read_value(new_client, DS1621_REG_CONF);
219 if (conf & DS1621_REG_CONFIG_NVB)
221 /* The 7 lowest bits of a temperature should always be 0. */
222 temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
225 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
228 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
233 /* Determine the chip type - only one kind supported! */
237 /* Fill in remaining client fields and put it into the global list */
238 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE);
240 new_client->id = ds1621_id++;
242 init_MUTEX(&data->update_lock);
244 /* Tell the I2C layer a new client has arrived */
245 if ((err = i2c_attach_client(new_client)))
248 /* Initialize the DS1621 chip */
249 ds1621_init_client(new_client);
251 /* Register sysfs hooks */
252 device_create_file(&new_client->dev, &dev_attr_alarms);
253 device_create_file(&new_client->dev, &dev_attr_temp1_input);
254 device_create_file(&new_client->dev, &dev_attr_temp1_min);
255 device_create_file(&new_client->dev, &dev_attr_temp1_max);
259 /* OK, this is not exactly good programming practice, usually. But it is
260 very code-efficient in this case. */
267 static int ds1621_detach_client(struct i2c_client *client)
271 if ((err = i2c_detach_client(client))) {
272 dev_err(&client->dev, "Client deregistration failed, "
273 "client not detached.\n");
277 kfree(i2c_get_clientdata(client));
283 static struct ds1621_data *ds1621_update_client(struct device *dev)
285 struct i2c_client *client = to_i2c_client(dev);
286 struct ds1621_data *data = i2c_get_clientdata(client);
289 down(&data->update_lock);
291 if ((jiffies - data->last_updated > HZ + HZ / 2) ||
292 (jiffies < data->last_updated) || !data->valid) {
294 dev_dbg(&client->dev, "Starting ds1621 update\n");
296 data->conf = ds1621_read_value(client, DS1621_REG_CONF);
298 data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
300 data->temp_min = ds1621_read_value(client,
301 DS1621_REG_TEMP_MIN);
302 data->temp_max = ds1621_read_value(client,
303 DS1621_REG_TEMP_MAX);
305 /* reset alarms if neccessary */
306 new_conf = data->conf;
307 if (data->temp < data->temp_min)
308 new_conf &= ~DS1621_ALARM_TEMP_LOW;
309 if (data->temp > data->temp_max)
310 new_conf &= ~DS1621_ALARM_TEMP_HIGH;
311 if (data->conf != new_conf)
312 ds1621_write_value(client, DS1621_REG_CONF,
315 data->last_updated = jiffies;
319 up(&data->update_lock);
324 static int __init ds1621_init(void)
326 return i2c_add_driver(&ds1621_driver);
329 static void __exit ds1621_exit(void)
331 i2c_del_driver(&ds1621_driver);
335 MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
336 MODULE_DESCRIPTION("DS1621 driver");
337 MODULE_LICENSE("GPL");
339 module_init(ds1621_init);
340 module_exit(ds1621_exit);