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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 ds1621.c - Part of lm_sensors, Linux kernel modules for hardware
3 monitoring
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>
8
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.
13
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.
18
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.
22*/
23
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>
Mark M. Hoffman943b0832005-07-15 21:39:18 -040029#include <linux/hwmon.h>
30#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include "lm75.h"
32
33/* Addresses to scan */
34static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
35 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070036
37/* Insmod parameters */
Jean Delvaref4b50262005-07-31 21:49:03 +020038I2C_CLIENT_INSMOD_1(ds1621);
Linus Torvalds1da177e2005-04-16 15:20:36 -070039static int polarity = -1;
40module_param(polarity, int, 0);
41MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
42
43/* Many DS1621 constants specified below */
44/* Config register used for detection */
45/* 7 6 5 4 3 2 1 0 */
46/* |Done|THF |TLF |NVB | X | X |POL |1SHOT| */
47#define DS1621_REG_CONFIG_NVB 0x10
48#define DS1621_REG_CONFIG_POLARITY 0x02
49#define DS1621_REG_CONFIG_1SHOT 0x01
50#define DS1621_REG_CONFIG_DONE 0x80
51
52/* The DS1621 registers */
53#define DS1621_REG_TEMP 0xAA /* word, RO */
54#define DS1621_REG_TEMP_MIN 0xA1 /* word, RW */
55#define DS1621_REG_TEMP_MAX 0xA2 /* word, RW */
56#define DS1621_REG_CONF 0xAC /* byte, RW */
57#define DS1621_COM_START 0xEE /* no data */
58#define DS1621_COM_STOP 0x22 /* no data */
59
60/* The DS1621 configuration register */
61#define DS1621_ALARM_TEMP_HIGH 0x40
62#define DS1621_ALARM_TEMP_LOW 0x20
63
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))
70
71/* Each client has this additional data */
72struct ds1621_data {
73 struct i2c_client client;
Mark M. Hoffman943b0832005-07-15 21:39:18 -040074 struct class_device *class_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 struct semaphore update_lock;
76 char valid; /* !=0 if following fields are valid */
77 unsigned long last_updated; /* In jiffies */
78
79 u16 temp, temp_min, temp_max; /* Register values, word */
80 u8 conf; /* Register encoding, combined */
81};
82
83static int ds1621_attach_adapter(struct i2c_adapter *adapter);
84static int ds1621_detect(struct i2c_adapter *adapter, int address,
85 int kind);
86static void ds1621_init_client(struct i2c_client *client);
87static int ds1621_detach_client(struct i2c_client *client);
88static struct ds1621_data *ds1621_update_client(struct device *dev);
89
90/* This is the driver that will be inserted */
91static struct i2c_driver ds1621_driver = {
92 .owner = THIS_MODULE,
93 .name = "ds1621",
94 .id = I2C_DRIVERID_DS1621,
95 .flags = I2C_DF_NOTIFY,
96 .attach_adapter = ds1621_attach_adapter,
97 .detach_client = ds1621_detach_client,
98};
99
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. */
103static int ds1621_read_value(struct i2c_client *client, u8 reg)
104{
105 if (reg == DS1621_REG_CONF)
106 return i2c_smbus_read_byte_data(client, reg);
107 else
108 return swab16(i2c_smbus_read_word_data(client, reg));
109}
110
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. */
114static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
115{
116 if (reg == DS1621_REG_CONF)
117 return i2c_smbus_write_byte_data(client, reg, value);
118 else
119 return i2c_smbus_write_word_data(client, reg, swab16(value));
120}
121
122static void ds1621_init_client(struct i2c_client *client)
123{
124 int reg = ds1621_read_value(client, DS1621_REG_CONF);
Steven Cole44bbe872005-05-03 18:21:25 -0600125 /* switch to continuous conversion mode */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126 reg &= ~ DS1621_REG_CONFIG_1SHOT;
127
128 /* setup output polarity */
129 if (polarity == 0)
130 reg &= ~DS1621_REG_CONFIG_POLARITY;
131 else if (polarity == 1)
132 reg |= DS1621_REG_CONFIG_POLARITY;
133
134 ds1621_write_value(client, DS1621_REG_CONF, reg);
135
136 /* start conversion */
137 i2c_smbus_write_byte(client, DS1621_COM_START);
138}
139
140#define show(value) \
Yani Ioannou30f74292005-05-17 06:41:35 -0400141static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142{ \
143 struct ds1621_data *data = ds1621_update_client(dev); \
144 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
145}
146
147show(temp);
148show(temp_min);
149show(temp_max);
150
151#define set_temp(suffix, value, reg) \
Yani Ioannou30f74292005-05-17 06:41:35 -0400152static ssize_t set_temp_##suffix(struct device *dev, struct device_attribute *attr, const char *buf, \
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 size_t count) \
154{ \
155 struct i2c_client *client = to_i2c_client(dev); \
156 struct ds1621_data *data = ds1621_update_client(dev); \
157 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
158 \
159 down(&data->update_lock); \
160 data->value = val; \
161 ds1621_write_value(client, reg, data->value); \
162 up(&data->update_lock); \
163 return count; \
164}
165
166set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
167set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
168
Yani Ioannou30f74292005-05-17 06:41:35 -0400169static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170{
171 struct ds1621_data *data = ds1621_update_client(dev);
172 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
173}
174
175static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
176static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
177static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min);
178static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
179
180
181static int ds1621_attach_adapter(struct i2c_adapter *adapter)
182{
Jean Delvareddec7482005-10-17 23:02:42 +0200183 if (!(adapter->class & I2C_CLASS_HWMON))
184 return 0;
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200185 return i2c_probe(adapter, &addr_data, ds1621_detect);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186}
187
Jean Delvare2ed2dc32005-07-31 21:42:02 +0200188/* This function is called by i2c_probe */
Ben Dooksc49efce2005-10-26 21:07:25 +0200189static int ds1621_detect(struct i2c_adapter *adapter, int address,
190 int kind)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191{
192 int conf, temp;
193 struct i2c_client *new_client;
194 struct ds1621_data *data;
195 int err = 0;
196
197 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
198 | I2C_FUNC_SMBUS_WORD_DATA
199 | I2C_FUNC_SMBUS_WRITE_BYTE))
200 goto exit;
201
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. */
Deepak Saxenaba9c2e82005-10-17 23:08:32 +0200205 if (!(data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 err = -ENOMEM;
207 goto exit;
208 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209
210 new_client = &data->client;
211 i2c_set_clientdata(new_client, data);
212 new_client->addr = address;
213 new_client->adapter = adapter;
214 new_client->driver = &ds1621_driver;
215 new_client->flags = 0;
216
217
218 /* Now, we do the remaining detection. It is lousy. */
219 if (kind < 0) {
220 /* The NVB bit should be low if no EEPROM write has been
221 requested during the latest 10ms, which is highly
222 improbable in our case. */
223 conf = ds1621_read_value(new_client, DS1621_REG_CONF);
224 if (conf & DS1621_REG_CONFIG_NVB)
225 goto exit_free;
226 /* The 7 lowest bits of a temperature should always be 0. */
227 temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
228 if (temp & 0x007f)
229 goto exit_free;
230 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
231 if (temp & 0x007f)
232 goto exit_free;
233 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
234 if (temp & 0x007f)
235 goto exit_free;
236 }
237
238 /* Determine the chip type - only one kind supported! */
239 if (kind <= 0)
240 kind = ds1621;
241
242 /* Fill in remaining client fields and put it into the global list */
243 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE);
244 data->valid = 0;
245 init_MUTEX(&data->update_lock);
246
247 /* Tell the I2C layer a new client has arrived */
248 if ((err = i2c_attach_client(new_client)))
249 goto exit_free;
250
251 /* Initialize the DS1621 chip */
252 ds1621_init_client(new_client);
253
254 /* Register sysfs hooks */
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400255 data->class_dev = hwmon_device_register(&new_client->dev);
256 if (IS_ERR(data->class_dev)) {
257 err = PTR_ERR(data->class_dev);
258 goto exit_detach;
259 }
260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 device_create_file(&new_client->dev, &dev_attr_alarms);
262 device_create_file(&new_client->dev, &dev_attr_temp1_input);
263 device_create_file(&new_client->dev, &dev_attr_temp1_min);
264 device_create_file(&new_client->dev, &dev_attr_temp1_max);
265
266 return 0;
267
268/* OK, this is not exactly good programming practice, usually. But it is
269 very code-efficient in this case. */
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400270 exit_detach:
271 i2c_detach_client(new_client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272 exit_free:
273 kfree(data);
274 exit:
275 return err;
276}
277
278static int ds1621_detach_client(struct i2c_client *client)
279{
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400280 struct ds1621_data *data = i2c_get_clientdata(client);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700281 int err;
282
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400283 hwmon_device_unregister(data->class_dev);
284
Jean Delvare7bef5592005-07-27 22:14:49 +0200285 if ((err = i2c_detach_client(client)))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 return err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287
Mark M. Hoffman943b0832005-07-15 21:39:18 -0400288 kfree(data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700289
290 return 0;
291}
292
293
294static struct ds1621_data *ds1621_update_client(struct device *dev)
295{
296 struct i2c_client *client = to_i2c_client(dev);
297 struct ds1621_data *data = i2c_get_clientdata(client);
298 u8 new_conf;
299
300 down(&data->update_lock);
301
302 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
303 || !data->valid) {
304
305 dev_dbg(&client->dev, "Starting ds1621 update\n");
306
307 data->conf = ds1621_read_value(client, DS1621_REG_CONF);
308
309 data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
310
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);
315
Steven Cole44bbe872005-05-03 18:21:25 -0600316 /* reset alarms if necessary */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 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,
324 new_conf);
325
326 data->last_updated = jiffies;
327 data->valid = 1;
328 }
329
330 up(&data->update_lock);
331
332 return data;
333}
334
335static int __init ds1621_init(void)
336{
337 return i2c_add_driver(&ds1621_driver);
338}
339
340static void __exit ds1621_exit(void)
341{
342 i2c_del_driver(&ds1621_driver);
343}
344
345
346MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
347MODULE_DESCRIPTION("DS1621 driver");
348MODULE_LICENSE("GPL");
349
350module_init(ds1621_init);
351module_exit(ds1621_exit);