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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/hwmon.h>
30#include <linux/hwmon-sysfs.h>
31#include <linux/err.h>
32#include <linux/mutex.h>
33#include <linux/sysfs.h>
34#include "lm75.h"
35
36/* Addresses to scan */
37static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c,
38 0x4d, 0x4e, 0x4f, I2C_CLIENT_END };
39
40/* Insmod parameters */
41static int polarity = -1;
42module_param(polarity, int, 0);
43MODULE_PARM_DESC(polarity, "Output's polarity: 0 = active high, 1 = active low");
44
45/* Many DS1621 constants specified below */
46/* Config register used for detection */
47/* 7 6 5 4 3 2 1 0 */
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
53
54/* The DS1621 registers */
55static const u8 DS1621_REG_TEMP[3] = {
56 0xAA, /* input, word, RO */
57 0xA2, /* min, word, RW */
58 0xA1, /* max, word, RW */
59};
60#define DS1621_REG_CONF 0xAC /* byte, RW */
61#define DS1621_COM_START 0xEE /* no data */
62#define DS1621_COM_STOP 0x22 /* no data */
63
64/* The DS1621 configuration register */
65#define DS1621_ALARM_TEMP_HIGH 0x40
66#define DS1621_ALARM_TEMP_LOW 0x20
67
68/* Conversions */
69#define ALARMS_FROM_REG(val) ((val) & \
70 (DS1621_ALARM_TEMP_HIGH | DS1621_ALARM_TEMP_LOW))
71
72/* Each client has this additional data */
73struct ds1621_data {
74 struct device *hwmon_dev;
75 struct mutex update_lock;
76 char valid; /* !=0 if following fields are valid */
77 unsigned long last_updated; /* In jiffies */
78
79 u16 temp[3]; /* Register values, word */
80 u8 conf; /* Register encoding, combined */
81};
82
83static void ds1621_init_client(struct i2c_client *client)
84{
85 u8 conf, new_conf;
86
87 new_conf = conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
88 /* switch to continuous conversion mode */
89 new_conf &= ~DS1621_REG_CONFIG_1SHOT;
90
91 /* setup output polarity */
92 if (polarity == 0)
93 new_conf &= ~DS1621_REG_CONFIG_POLARITY;
94 else if (polarity == 1)
95 new_conf |= DS1621_REG_CONFIG_POLARITY;
96
97 if (conf != new_conf)
98 i2c_smbus_write_byte_data(client, DS1621_REG_CONF, new_conf);
99
100 /* start conversion */
101 i2c_smbus_write_byte(client, DS1621_COM_START);
102}
103
104static struct ds1621_data *ds1621_update_client(struct device *dev)
105{
106 struct i2c_client *client = to_i2c_client(dev);
107 struct ds1621_data *data = i2c_get_clientdata(client);
108 u8 new_conf;
109
110 mutex_lock(&data->update_lock);
111
112 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
113 || !data->valid) {
114 int i;
115
116 dev_dbg(&client->dev, "Starting ds1621 update\n");
117
118 data->conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
119
120 for (i = 0; i < ARRAY_SIZE(data->temp); i++)
121 data->temp[i] = i2c_smbus_read_word_swapped(client,
122 DS1621_REG_TEMP[i]);
123
124 /* reset alarms if necessary */
125 new_conf = data->conf;
126 if (data->temp[0] > data->temp[1]) /* input > min */
127 new_conf &= ~DS1621_ALARM_TEMP_LOW;
128 if (data->temp[0] < data->temp[2]) /* input < max */
129 new_conf &= ~DS1621_ALARM_TEMP_HIGH;
130 if (data->conf != new_conf)
131 i2c_smbus_write_byte_data(client, DS1621_REG_CONF,
132 new_conf);
133
134 data->last_updated = jiffies;
135 data->valid = 1;
136 }
137
138 mutex_unlock(&data->update_lock);
139
140 return data;
141}
142
143static ssize_t show_temp(struct device *dev, struct device_attribute *da,
144 char *buf)
145{
146 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
147 struct ds1621_data *data = ds1621_update_client(dev);
148 return sprintf(buf, "%d\n",
149 LM75_TEMP_FROM_REG(data->temp[attr->index]));
150}
151
152static ssize_t set_temp(struct device *dev, struct device_attribute *da,
153 const char *buf, size_t count)
154{
155 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
156 struct i2c_client *client = to_i2c_client(dev);
157 struct ds1621_data *data = i2c_get_clientdata(client);
158 long val;
159 int err;
160
161 err = kstrtol(buf, 10, &val);
162 if (err)
163 return err;
164
165 mutex_lock(&data->update_lock);
166 data->temp[attr->index] = LM75_TEMP_TO_REG(val);
167 i2c_smbus_write_word_swapped(client, DS1621_REG_TEMP[attr->index],
168 data->temp[attr->index]);
169 mutex_unlock(&data->update_lock);
170 return count;
171}
172
173static ssize_t show_alarms(struct device *dev, struct device_attribute *da,
174 char *buf)
175{
176 struct ds1621_data *data = ds1621_update_client(dev);
177 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->conf));
178}
179
180static ssize_t show_alarm(struct device *dev, struct device_attribute *da,
181 char *buf)
182{
183 struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
184 struct ds1621_data *data = ds1621_update_client(dev);
185 return sprintf(buf, "%d\n", !!(data->conf & attr->index));
186}
187
188static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
189static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
190static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp, 1);
191static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp, 2);
192static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
193 DS1621_ALARM_TEMP_LOW);
194static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
195 DS1621_ALARM_TEMP_HIGH);
196
197static struct attribute *ds1621_attributes[] = {
198 &sensor_dev_attr_temp1_input.dev_attr.attr,
199 &sensor_dev_attr_temp1_min.dev_attr.attr,
200 &sensor_dev_attr_temp1_max.dev_attr.attr,
201 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
202 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
203 &dev_attr_alarms.attr,
204 NULL
205};
206
207static const struct attribute_group ds1621_group = {
208 .attrs = ds1621_attributes,
209};
210
211
212/* Return 0 if detection is successful, -ENODEV otherwise */
213static int ds1621_detect(struct i2c_client *client,
214 struct i2c_board_info *info)
215{
216 struct i2c_adapter *adapter = client->adapter;
217 int conf, temp;
218 int i;
219
220 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
221 | I2C_FUNC_SMBUS_WORD_DATA
222 | I2C_FUNC_SMBUS_WRITE_BYTE))
223 return -ENODEV;
224
225 /*
226 * Now, we do the remaining detection. It is lousy.
227 *
228 * The NVB bit should be low if no EEPROM write has been requested
229 * during the latest 10ms, which is highly improbable in our case.
230 */
231 conf = i2c_smbus_read_byte_data(client, DS1621_REG_CONF);
232 if (conf < 0 || conf & DS1621_REG_CONFIG_NVB)
233 return -ENODEV;
234 /* The 7 lowest bits of a temperature should always be 0. */
235 for (i = 0; i < ARRAY_SIZE(DS1621_REG_TEMP); i++) {
236 temp = i2c_smbus_read_word_data(client, DS1621_REG_TEMP[i]);
237 if (temp < 0 || (temp & 0x7f00))
238 return -ENODEV;
239 }
240
241 strlcpy(info->type, "ds1621", I2C_NAME_SIZE);
242
243 return 0;
244}
245
246static int ds1621_probe(struct i2c_client *client,
247 const struct i2c_device_id *id)
248{
249 struct ds1621_data *data;
250 int err;
251
252 data = kzalloc(sizeof(struct ds1621_data), GFP_KERNEL);
253 if (!data) {
254 err = -ENOMEM;
255 goto exit;
256 }
257
258 i2c_set_clientdata(client, data);
259 mutex_init(&data->update_lock);
260
261 /* Initialize the DS1621 chip */
262 ds1621_init_client(client);
263
264 /* Register sysfs hooks */
265 err = sysfs_create_group(&client->dev.kobj, &ds1621_group);
266 if (err)
267 goto exit_free;
268
269 data->hwmon_dev = hwmon_device_register(&client->dev);
270 if (IS_ERR(data->hwmon_dev)) {
271 err = PTR_ERR(data->hwmon_dev);
272 goto exit_remove_files;
273 }
274
275 return 0;
276
277 exit_remove_files:
278 sysfs_remove_group(&client->dev.kobj, &ds1621_group);
279 exit_free:
280 kfree(data);
281 exit:
282 return err;
283}
284
285static int ds1621_remove(struct i2c_client *client)
286{
287 struct ds1621_data *data = i2c_get_clientdata(client);
288
289 hwmon_device_unregister(data->hwmon_dev);
290 sysfs_remove_group(&client->dev.kobj, &ds1621_group);
291
292 kfree(data);
293
294 return 0;
295}
296
297static const struct i2c_device_id ds1621_id[] = {
298 { "ds1621", 0 },
299 { "ds1625", 0 },
300 { }
301};
302MODULE_DEVICE_TABLE(i2c, ds1621_id);
303
304/* This is the driver that will be inserted */
305static struct i2c_driver ds1621_driver = {
306 .class = I2C_CLASS_HWMON,
307 .driver = {
308 .name = "ds1621",
309 },
310 .probe = ds1621_probe,
311 .remove = ds1621_remove,
312 .id_table = ds1621_id,
313 .detect = ds1621_detect,
314 .address_list = normal_i2c,
315};
316
317module_i2c_driver(ds1621_driver);
318
319MODULE_AUTHOR("Christian W. Zuckschwerdt <zany@triq.net>");
320MODULE_DESCRIPTION("DS1621 driver");
321MODULE_LICENSE("GPL");