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Diffstat (limited to 'drivers/i2c/chips/ds1621.c')
-rw-r--r--drivers/i2c/chips/ds1621.c341
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/i2c/chips/ds1621.c b/drivers/i2c/chips/ds1621.c
new file mode 100644
index 000000000000..bb1fefb2162e
--- /dev/null
+++ b/drivers/i2c/chips/ds1621.c
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1/*
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>
29#include <linux/i2c-sensor.h>
30#include "lm75.h"
31
32/* Addresses to scan */
33static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
34 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
35static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
36
37/* Insmod parameters */
38SENSORS_INSMOD_1(ds1621);
39static 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;
74 struct semaphore update_lock;
75 char valid; /* !=0 if following fields are valid */
76 unsigned long last_updated; /* In jiffies */
77
78 u16 temp, temp_min, temp_max; /* Register values, word */
79 u8 conf; /* Register encoding, combined */
80};
81
82static int ds1621_attach_adapter(struct i2c_adapter *adapter);
83static int ds1621_detect(struct i2c_adapter *adapter, int address,
84 int kind);
85static void ds1621_init_client(struct i2c_client *client);
86static int ds1621_detach_client(struct i2c_client *client);
87static struct ds1621_data *ds1621_update_client(struct device *dev);
88
89/* This is the driver that will be inserted */
90static struct i2c_driver ds1621_driver = {
91 .owner = THIS_MODULE,
92 .name = "ds1621",
93 .id = I2C_DRIVERID_DS1621,
94 .flags = I2C_DF_NOTIFY,
95 .attach_adapter = ds1621_attach_adapter,
96 .detach_client = ds1621_detach_client,
97};
98
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 usual practice. */
102static int ds1621_read_value(struct i2c_client *client, u8 reg)
103{
104 if (reg == DS1621_REG_CONF)
105 return i2c_smbus_read_byte_data(client, reg);
106 else
107 return swab16(i2c_smbus_read_word_data(client, reg));
108}
109
110/* All registers are word-sized, except for the configuration register.
111 DS1621 uses a high-byte first convention, which is exactly opposite to
112 the usual practice. */
113static int ds1621_write_value(struct i2c_client *client, u8 reg, u16 value)
114{
115 if (reg == DS1621_REG_CONF)
116 return i2c_smbus_write_byte_data(client, reg, value);
117 else
118 return i2c_smbus_write_word_data(client, reg, swab16(value));
119}
120
121static void ds1621_init_client(struct i2c_client *client)
122{
123 int reg = ds1621_read_value(client, DS1621_REG_CONF);
124 /* switch to continous conversion mode */
125 reg &= ~ DS1621_REG_CONFIG_1SHOT;
126
127 /* setup output polarity */
128 if (polarity == 0)
129 reg &= ~DS1621_REG_CONFIG_POLARITY;
130 else if (polarity == 1)
131 reg |= DS1621_REG_CONFIG_POLARITY;
132
133 ds1621_write_value(client, DS1621_REG_CONF, reg);
134
135 /* start conversion */
136 i2c_smbus_write_byte(client, DS1621_COM_START);
137}
138
139#define show(value) \
140static ssize_t show_##value(struct device *dev, char *buf) \
141{ \
142 struct ds1621_data *data = ds1621_update_client(dev); \
143 return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \
144}
145
146show(temp);
147show(temp_min);
148show(temp_max);
149
150#define set_temp(suffix, value, reg) \
151static ssize_t set_temp_##suffix(struct device *dev, const char *buf, \
152 size_t count) \
153{ \
154 struct i2c_client *client = to_i2c_client(dev); \
155 struct ds1621_data *data = ds1621_update_client(dev); \
156 u16 val = LM75_TEMP_TO_REG(simple_strtoul(buf, NULL, 10)); \
157 \
158 down(&data->update_lock); \
159 data->value = val; \
160 ds1621_write_value(client, reg, data->value); \
161 up(&data->update_lock); \
162 return count; \
163}
164
165set_temp(min, temp_min, DS1621_REG_TEMP_MIN);
166set_temp(max, temp_max, DS1621_REG_TEMP_MAX);
167
168static ssize_t show_alarms(struct device *dev, char *buf)
169{
170 struct ds1621_data *data = ds1621_update_client(dev);
171 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
172}
173
174static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
175static DEVICE_ATTR(temp1_input, S_IRUGO , show_temp, NULL);
176static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO , show_temp_min, set_temp_min);
177static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max);
178
179
180static int ds1621_attach_adapter(struct i2c_adapter *adapter)
181{
182 return i2c_detect(adapter, &addr_data, ds1621_detect);
183}
184
185/* This function is called by i2c_detect */
186int ds1621_detect(struct i2c_adapter *adapter, int address,
187 int kind)
188{
189 int conf, temp;
190 struct i2c_client *new_client;
191 struct ds1621_data *data;
192 int err = 0;
193
194 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
195 | I2C_FUNC_SMBUS_WORD_DATA
196 | I2C_FUNC_SMBUS_WRITE_BYTE))
197 goto exit;
198
199 /* OK. For now, we presume we have a valid client. We now create the
200 client structure, even though we cannot fill it completely yet.
201 But it allows us to access ds1621_{read,write}_value. */
202 if (!(data = kmalloc(sizeof(struct ds1621_data), GFP_KERNEL))) {
203 err = -ENOMEM;
204 goto exit;
205 }
206 memset(data, 0, sizeof(struct ds1621_data));
207
208 new_client = &data->client;
209 i2c_set_clientdata(new_client, data);
210 new_client->addr = address;
211 new_client->adapter = adapter;
212 new_client->driver = &ds1621_driver;
213 new_client->flags = 0;
214
215
216 /* Now, we do the remaining detection. It is lousy. */
217 if (kind < 0) {
218 /* The NVB bit should be low if no EEPROM write has been
219 requested during the latest 10ms, which is highly
220 improbable in our case. */
221 conf = ds1621_read_value(new_client, DS1621_REG_CONF);
222 if (conf & DS1621_REG_CONFIG_NVB)
223 goto exit_free;
224 /* The 7 lowest bits of a temperature should always be 0. */
225 temp = ds1621_read_value(new_client, DS1621_REG_TEMP);
226 if (temp & 0x007f)
227 goto exit_free;
228 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MIN);
229 if (temp & 0x007f)
230 goto exit_free;
231 temp = ds1621_read_value(new_client, DS1621_REG_TEMP_MAX);
232 if (temp & 0x007f)
233 goto exit_free;
234 }
235
236 /* Determine the chip type - only one kind supported! */
237 if (kind <= 0)
238 kind = ds1621;
239
240 /* Fill in remaining client fields and put it into the global list */
241 strlcpy(new_client->name, "ds1621", I2C_NAME_SIZE);
242 data->valid = 0;
243 init_MUTEX(&data->update_lock);
244
245 /* Tell the I2C layer a new client has arrived */
246 if ((err = i2c_attach_client(new_client)))
247 goto exit_free;
248
249 /* Initialize the DS1621 chip */
250 ds1621_init_client(new_client);
251
252 /* Register sysfs hooks */
253 device_create_file(&new_client->dev, &dev_attr_alarms);
254 device_create_file(&new_client->dev, &dev_attr_temp1_input);
255 device_create_file(&new_client->dev, &dev_attr_temp1_min);
256 device_create_file(&new_client->dev, &dev_attr_temp1_max);
257
258 return 0;
259
260/* OK, this is not exactly good programming practice, usually. But it is
261 very code-efficient in this case. */
262 exit_free:
263 kfree(data);
264 exit:
265 return err;
266}
267
268static int ds1621_detach_client(struct i2c_client *client)
269{
270 int err;
271
272 if ((err = i2c_detach_client(client))) {
273 dev_err(&client->dev, "Client deregistration failed, "
274 "client not detached.\n");
275 return err;
276 }
277
278 kfree(i2c_get_clientdata(client));
279
280 return 0;
281}
282
283
284static struct ds1621_data *ds1621_update_client(struct device *dev)
285{
286 struct i2c_client *client = to_i2c_client(dev);
287 struct ds1621_data *data = i2c_get_clientdata(client);
288 u8 new_conf;
289
290 down(&data->update_lock);
291
292 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
293 || !data->valid) {
294
295 dev_dbg(&client->dev, "Starting ds1621 update\n");
296
297 data->conf = ds1621_read_value(client, DS1621_REG_CONF);
298
299 data->temp = ds1621_read_value(client, DS1621_REG_TEMP);
300
301 data->temp_min = ds1621_read_value(client,
302 DS1621_REG_TEMP_MIN);
303 data->temp_max = ds1621_read_value(client,
304 DS1621_REG_TEMP_MAX);
305
306 /* reset alarms if neccessary */
307 new_conf = data->conf;
308 if (data->temp < data->temp_min)
309 new_conf &= ~DS1621_ALARM_TEMP_LOW;
310 if (data->temp > data->temp_max)
311 new_conf &= ~DS1621_ALARM_TEMP_HIGH;
312 if (data->conf != new_conf)
313 ds1621_write_value(client, DS1621_REG_CONF,
314 new_conf);
315
316 data->last_updated = jiffies;
317 data->valid = 1;
318 }
319
320 up(&data->update_lock);
321
322 return data;
323}
324
325static int __init ds1621_init(void)
326{
327 return i2c_add_driver(&ds1621_driver);
328}
329
330static void __exit ds1621_exit(void)
331{
332 i2c_del_driver(&ds1621_driver);
333}
334
335
336MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
337MODULE_DESCRIPTION("DS1621 driver");
338MODULE_LICENSE("GPL");
339
340module_init(ds1621_init);
341module_exit(ds1621_exit);