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1da177e4 LT |
1 | /* |
2 | lm75.c - Part of lm_sensors, Linux kernel modules for hardware | |
3 | monitoring | |
4 | Copyright (c) 1998, 1999 Frodo Looijaard <frodol@dds.nl> | |
5 | ||
6 | This program is free software; you can redistribute it and/or modify | |
7 | it under the terms of the GNU General Public License as published by | |
8 | the Free Software Foundation; either version 2 of the License, or | |
9 | (at your option) any later version. | |
10 | ||
11 | This program is distributed in the hope that it will be useful, | |
12 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
14 | GNU General Public License for more details. | |
15 | ||
16 | You should have received a copy of the GNU General Public License | |
17 | along with this program; if not, write to the Free Software | |
18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. | |
19 | */ | |
20 | ||
1da177e4 LT |
21 | #include <linux/module.h> |
22 | #include <linux/init.h> | |
23 | #include <linux/slab.h> | |
24 | #include <linux/jiffies.h> | |
25 | #include <linux/i2c.h> | |
943b0830 | 26 | #include <linux/hwmon.h> |
9ca8e40c | 27 | #include <linux/hwmon-sysfs.h> |
943b0830 | 28 | #include <linux/err.h> |
9a61bf63 | 29 | #include <linux/mutex.h> |
1da177e4 LT |
30 | #include "lm75.h" |
31 | ||
32 | ||
33 | /* Addresses to scan */ | |
34 | static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, 0x4c, | |
35 | 0x4d, 0x4e, 0x4f, I2C_CLIENT_END }; | |
1da177e4 LT |
36 | |
37 | /* Insmod parameters */ | |
f4b50261 | 38 | I2C_CLIENT_INSMOD_1(lm75); |
1da177e4 LT |
39 | |
40 | /* Many LM75 constants specified below */ | |
41 | ||
42 | /* The LM75 registers */ | |
1da177e4 | 43 | #define LM75_REG_CONF 0x01 |
9ca8e40c JD |
44 | static const u8 LM75_REG_TEMP[3] = { |
45 | 0x00, /* input */ | |
46 | 0x03, /* max */ | |
47 | 0x02, /* hyst */ | |
48 | }; | |
1da177e4 LT |
49 | |
50 | /* Each client has this additional data */ | |
51 | struct lm75_data { | |
52 | struct i2c_client client; | |
1beeffe4 | 53 | struct device *hwmon_dev; |
9a61bf63 | 54 | struct mutex update_lock; |
1da177e4 LT |
55 | char valid; /* !=0 if following fields are valid */ |
56 | unsigned long last_updated; /* In jiffies */ | |
9ca8e40c JD |
57 | u16 temp[3]; /* Register values, |
58 | 0 = input | |
59 | 1 = max | |
60 | 2 = hyst */ | |
1da177e4 LT |
61 | }; |
62 | ||
63 | static int lm75_attach_adapter(struct i2c_adapter *adapter); | |
64 | static int lm75_detect(struct i2c_adapter *adapter, int address, int kind); | |
65 | static void lm75_init_client(struct i2c_client *client); | |
66 | static int lm75_detach_client(struct i2c_client *client); | |
67 | static int lm75_read_value(struct i2c_client *client, u8 reg); | |
68 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); | |
69 | static struct lm75_data *lm75_update_device(struct device *dev); | |
70 | ||
71 | ||
72 | /* This is the driver that will be inserted */ | |
73 | static struct i2c_driver lm75_driver = { | |
cdaf7934 | 74 | .driver = { |
cdaf7934 LR |
75 | .name = "lm75", |
76 | }, | |
1da177e4 | 77 | .id = I2C_DRIVERID_LM75, |
1da177e4 LT |
78 | .attach_adapter = lm75_attach_adapter, |
79 | .detach_client = lm75_detach_client, | |
80 | }; | |
81 | ||
9ca8e40c JD |
82 | static ssize_t show_temp(struct device *dev, struct device_attribute *da, |
83 | char *buf) | |
84 | { | |
85 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
86 | struct lm75_data *data = lm75_update_device(dev); | |
87 | return sprintf(buf, "%d\n", | |
88 | LM75_TEMP_FROM_REG(data->temp[attr->index])); | |
1da177e4 | 89 | } |
9ca8e40c JD |
90 | |
91 | static ssize_t set_temp(struct device *dev, struct device_attribute *da, | |
92 | const char *buf, size_t count) | |
93 | { | |
94 | struct sensor_device_attribute *attr = to_sensor_dev_attr(da); | |
95 | struct i2c_client *client = to_i2c_client(dev); | |
96 | struct lm75_data *data = i2c_get_clientdata(client); | |
97 | int nr = attr->index; | |
5bfedac0 | 98 | long temp = simple_strtol(buf, NULL, 10); |
9ca8e40c JD |
99 | |
100 | mutex_lock(&data->update_lock); | |
101 | data->temp[nr] = LM75_TEMP_TO_REG(temp); | |
102 | lm75_write_value(client, LM75_REG_TEMP[nr], data->temp[nr]); | |
103 | mutex_unlock(&data->update_lock); | |
104 | return count; | |
1da177e4 | 105 | } |
1da177e4 | 106 | |
9ca8e40c JD |
107 | static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, |
108 | show_temp, set_temp, 1); | |
109 | static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, | |
110 | show_temp, set_temp, 2); | |
111 | static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0); | |
1da177e4 LT |
112 | |
113 | static int lm75_attach_adapter(struct i2c_adapter *adapter) | |
114 | { | |
115 | if (!(adapter->class & I2C_CLASS_HWMON)) | |
116 | return 0; | |
2ed2dc3c | 117 | return i2c_probe(adapter, &addr_data, lm75_detect); |
1da177e4 LT |
118 | } |
119 | ||
c1685f61 | 120 | static struct attribute *lm75_attributes[] = { |
9ca8e40c JD |
121 | &sensor_dev_attr_temp1_input.dev_attr.attr, |
122 | &sensor_dev_attr_temp1_max.dev_attr.attr, | |
123 | &sensor_dev_attr_temp1_max_hyst.dev_attr.attr, | |
c1685f61 MH |
124 | |
125 | NULL | |
126 | }; | |
127 | ||
128 | static const struct attribute_group lm75_group = { | |
129 | .attrs = lm75_attributes, | |
130 | }; | |
131 | ||
2ed2dc3c | 132 | /* This function is called by i2c_probe */ |
1da177e4 LT |
133 | static int lm75_detect(struct i2c_adapter *adapter, int address, int kind) |
134 | { | |
135 | int i; | |
136 | struct i2c_client *new_client; | |
137 | struct lm75_data *data; | |
138 | int err = 0; | |
139 | const char *name = ""; | |
140 | ||
1da177e4 LT |
141 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | |
142 | I2C_FUNC_SMBUS_WORD_DATA)) | |
143 | goto exit; | |
144 | ||
145 | /* OK. For now, we presume we have a valid client. We now create the | |
146 | client structure, even though we cannot fill it completely yet. | |
147 | But it allows us to access lm75_{read,write}_value. */ | |
ba9c2e8d | 148 | if (!(data = kzalloc(sizeof(struct lm75_data), GFP_KERNEL))) { |
1da177e4 LT |
149 | err = -ENOMEM; |
150 | goto exit; | |
151 | } | |
1da177e4 LT |
152 | |
153 | new_client = &data->client; | |
154 | i2c_set_clientdata(new_client, data); | |
155 | new_client->addr = address; | |
156 | new_client->adapter = adapter; | |
157 | new_client->driver = &lm75_driver; | |
158 | new_client->flags = 0; | |
159 | ||
160 | /* Now, we do the remaining detection. There is no identification- | |
161 | dedicated register so we have to rely on several tricks: | |
162 | unused bits, registers cycling over 8-address boundaries, | |
163 | addresses 0x04-0x07 returning the last read value. | |
164 | The cycling+unused addresses combination is not tested, | |
165 | since it would significantly slow the detection down and would | |
166 | hardly add any value. */ | |
167 | if (kind < 0) { | |
168 | int cur, conf, hyst, os; | |
169 | ||
170 | /* Unused addresses */ | |
171 | cur = i2c_smbus_read_word_data(new_client, 0); | |
172 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
173 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
174 | if (i2c_smbus_read_word_data(new_client, 4) != hyst | |
175 | || i2c_smbus_read_word_data(new_client, 5) != hyst | |
176 | || i2c_smbus_read_word_data(new_client, 6) != hyst | |
177 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
178 | goto exit_free; | |
179 | os = i2c_smbus_read_word_data(new_client, 3); | |
180 | if (i2c_smbus_read_word_data(new_client, 4) != os | |
181 | || i2c_smbus_read_word_data(new_client, 5) != os | |
182 | || i2c_smbus_read_word_data(new_client, 6) != os | |
183 | || i2c_smbus_read_word_data(new_client, 7) != os) | |
184 | goto exit_free; | |
185 | ||
186 | /* Unused bits */ | |
187 | if (conf & 0xe0) | |
188 | goto exit_free; | |
189 | ||
190 | /* Addresses cycling */ | |
191 | for (i = 8; i < 0xff; i += 8) | |
192 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
193 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
194 | || i2c_smbus_read_word_data(new_client, i + 3) != os) | |
195 | goto exit_free; | |
196 | } | |
197 | ||
198 | /* Determine the chip type - only one kind supported! */ | |
199 | if (kind <= 0) | |
200 | kind = lm75; | |
201 | ||
202 | if (kind == lm75) { | |
203 | name = "lm75"; | |
204 | } | |
205 | ||
206 | /* Fill in the remaining client fields and put it into the global list */ | |
207 | strlcpy(new_client->name, name, I2C_NAME_SIZE); | |
208 | data->valid = 0; | |
9a61bf63 | 209 | mutex_init(&data->update_lock); |
1da177e4 LT |
210 | |
211 | /* Tell the I2C layer a new client has arrived */ | |
212 | if ((err = i2c_attach_client(new_client))) | |
213 | goto exit_free; | |
214 | ||
215 | /* Initialize the LM75 chip */ | |
216 | lm75_init_client(new_client); | |
217 | ||
218 | /* Register sysfs hooks */ | |
c1685f61 MH |
219 | if ((err = sysfs_create_group(&new_client->dev.kobj, &lm75_group))) |
220 | goto exit_detach; | |
221 | ||
1beeffe4 TJ |
222 | data->hwmon_dev = hwmon_device_register(&new_client->dev); |
223 | if (IS_ERR(data->hwmon_dev)) { | |
224 | err = PTR_ERR(data->hwmon_dev); | |
c1685f61 | 225 | goto exit_remove; |
943b0830 MH |
226 | } |
227 | ||
1da177e4 LT |
228 | return 0; |
229 | ||
c1685f61 MH |
230 | exit_remove: |
231 | sysfs_remove_group(&new_client->dev.kobj, &lm75_group); | |
943b0830 MH |
232 | exit_detach: |
233 | i2c_detach_client(new_client); | |
1da177e4 LT |
234 | exit_free: |
235 | kfree(data); | |
236 | exit: | |
237 | return err; | |
238 | } | |
239 | ||
240 | static int lm75_detach_client(struct i2c_client *client) | |
241 | { | |
943b0830 | 242 | struct lm75_data *data = i2c_get_clientdata(client); |
1beeffe4 | 243 | hwmon_device_unregister(data->hwmon_dev); |
c1685f61 | 244 | sysfs_remove_group(&client->dev.kobj, &lm75_group); |
1da177e4 | 245 | i2c_detach_client(client); |
943b0830 | 246 | kfree(data); |
1da177e4 LT |
247 | return 0; |
248 | } | |
249 | ||
250 | /* All registers are word-sized, except for the configuration register. | |
251 | LM75 uses a high-byte first convention, which is exactly opposite to | |
252 | the usual practice. */ | |
253 | static int lm75_read_value(struct i2c_client *client, u8 reg) | |
254 | { | |
255 | if (reg == LM75_REG_CONF) | |
256 | return i2c_smbus_read_byte_data(client, reg); | |
257 | else | |
258 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
259 | } | |
260 | ||
261 | /* All registers are word-sized, except for the configuration register. | |
262 | LM75 uses a high-byte first convention, which is exactly opposite to | |
263 | the usual practice. */ | |
264 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) | |
265 | { | |
266 | if (reg == LM75_REG_CONF) | |
267 | return i2c_smbus_write_byte_data(client, reg, value); | |
268 | else | |
269 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
270 | } | |
271 | ||
272 | static void lm75_init_client(struct i2c_client *client) | |
273 | { | |
e647ecf1 JD |
274 | int reg; |
275 | ||
276 | /* Enable if in shutdown mode */ | |
277 | reg = lm75_read_value(client, LM75_REG_CONF); | |
278 | if (reg >= 0 && (reg & 0x01)) | |
279 | lm75_write_value(client, LM75_REG_CONF, reg & 0xfe); | |
1da177e4 LT |
280 | } |
281 | ||
282 | static struct lm75_data *lm75_update_device(struct device *dev) | |
283 | { | |
284 | struct i2c_client *client = to_i2c_client(dev); | |
285 | struct lm75_data *data = i2c_get_clientdata(client); | |
286 | ||
9a61bf63 | 287 | mutex_lock(&data->update_lock); |
1da177e4 LT |
288 | |
289 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
290 | || !data->valid) { | |
9ca8e40c | 291 | int i; |
1da177e4 LT |
292 | dev_dbg(&client->dev, "Starting lm75 update\n"); |
293 | ||
9ca8e40c JD |
294 | for (i = 0; i < ARRAY_SIZE(data->temp); i++) |
295 | data->temp[i] = lm75_read_value(client, | |
296 | LM75_REG_TEMP[i]); | |
1da177e4 LT |
297 | data->last_updated = jiffies; |
298 | data->valid = 1; | |
299 | } | |
300 | ||
9a61bf63 | 301 | mutex_unlock(&data->update_lock); |
1da177e4 LT |
302 | |
303 | return data; | |
304 | } | |
305 | ||
306 | static int __init sensors_lm75_init(void) | |
307 | { | |
308 | return i2c_add_driver(&lm75_driver); | |
309 | } | |
310 | ||
311 | static void __exit sensors_lm75_exit(void) | |
312 | { | |
313 | i2c_del_driver(&lm75_driver); | |
314 | } | |
315 | ||
316 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); | |
317 | MODULE_DESCRIPTION("LM75 driver"); | |
318 | MODULE_LICENSE("GPL"); | |
319 | ||
320 | module_init(sensors_lm75_init); | |
321 | module_exit(sensors_lm75_exit); |