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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 | ||
21 | #include <linux/config.h> | |
22 | #include <linux/module.h> | |
23 | #include <linux/init.h> | |
24 | #include <linux/slab.h> | |
25 | #include <linux/jiffies.h> | |
26 | #include <linux/i2c.h> | |
27 | #include <linux/i2c-sensor.h> | |
28 | #include "lm75.h" | |
29 | ||
30 | ||
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 }; | |
35 | ||
36 | /* Insmod parameters */ | |
37 | SENSORS_INSMOD_1(lm75); | |
38 | ||
39 | /* Many LM75 constants specified below */ | |
40 | ||
41 | /* The LM75 registers */ | |
42 | #define LM75_REG_TEMP 0x00 | |
43 | #define LM75_REG_CONF 0x01 | |
44 | #define LM75_REG_TEMP_HYST 0x02 | |
45 | #define LM75_REG_TEMP_OS 0x03 | |
46 | ||
47 | /* Each client has this additional data */ | |
48 | struct lm75_data { | |
49 | struct i2c_client client; | |
50 | struct semaphore update_lock; | |
51 | char valid; /* !=0 if following fields are valid */ | |
52 | unsigned long last_updated; /* In jiffies */ | |
53 | u16 temp_input; /* Register values */ | |
54 | u16 temp_max; | |
55 | u16 temp_hyst; | |
56 | }; | |
57 | ||
58 | static int lm75_attach_adapter(struct i2c_adapter *adapter); | |
59 | static int lm75_detect(struct i2c_adapter *adapter, int address, int kind); | |
60 | static void lm75_init_client(struct i2c_client *client); | |
61 | static int lm75_detach_client(struct i2c_client *client); | |
62 | static int lm75_read_value(struct i2c_client *client, u8 reg); | |
63 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value); | |
64 | static struct lm75_data *lm75_update_device(struct device *dev); | |
65 | ||
66 | ||
67 | /* This is the driver that will be inserted */ | |
68 | static struct i2c_driver lm75_driver = { | |
69 | .owner = THIS_MODULE, | |
70 | .name = "lm75", | |
71 | .id = I2C_DRIVERID_LM75, | |
72 | .flags = I2C_DF_NOTIFY, | |
73 | .attach_adapter = lm75_attach_adapter, | |
74 | .detach_client = lm75_detach_client, | |
75 | }; | |
76 | ||
77 | #define show(value) \ | |
30f74292 | 78 | static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \ |
1da177e4 LT |
79 | { \ |
80 | struct lm75_data *data = lm75_update_device(dev); \ | |
81 | return sprintf(buf, "%d\n", LM75_TEMP_FROM_REG(data->value)); \ | |
82 | } | |
83 | show(temp_max); | |
84 | show(temp_hyst); | |
85 | show(temp_input); | |
86 | ||
87 | #define set(value, reg) \ | |
30f74292 | 88 | static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \ |
1da177e4 LT |
89 | { \ |
90 | struct i2c_client *client = to_i2c_client(dev); \ | |
91 | struct lm75_data *data = i2c_get_clientdata(client); \ | |
92 | int temp = simple_strtoul(buf, NULL, 10); \ | |
93 | \ | |
94 | down(&data->update_lock); \ | |
95 | data->value = LM75_TEMP_TO_REG(temp); \ | |
96 | lm75_write_value(client, reg, data->value); \ | |
97 | up(&data->update_lock); \ | |
98 | return count; \ | |
99 | } | |
100 | set(temp_max, LM75_REG_TEMP_OS); | |
101 | set(temp_hyst, LM75_REG_TEMP_HYST); | |
102 | ||
103 | static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp_max, set_temp_max); | |
104 | static DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO, show_temp_hyst, set_temp_hyst); | |
105 | static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp_input, NULL); | |
106 | ||
107 | static int lm75_attach_adapter(struct i2c_adapter *adapter) | |
108 | { | |
109 | if (!(adapter->class & I2C_CLASS_HWMON)) | |
110 | return 0; | |
111 | return i2c_detect(adapter, &addr_data, lm75_detect); | |
112 | } | |
113 | ||
114 | /* This function is called by i2c_detect */ | |
115 | static int lm75_detect(struct i2c_adapter *adapter, int address, int kind) | |
116 | { | |
117 | int i; | |
118 | struct i2c_client *new_client; | |
119 | struct lm75_data *data; | |
120 | int err = 0; | |
121 | const char *name = ""; | |
122 | ||
123 | /* Make sure we aren't probing the ISA bus!! This is just a safety check | |
124 | at this moment; i2c_detect really won't call us. */ | |
125 | #ifdef DEBUG | |
126 | if (i2c_is_isa_adapter(adapter)) { | |
127 | dev_dbg(&adapter->dev, | |
128 | "lm75_detect called for an ISA bus adapter?!?\n"); | |
129 | goto exit; | |
130 | } | |
131 | #endif | |
132 | ||
133 | if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA | | |
134 | I2C_FUNC_SMBUS_WORD_DATA)) | |
135 | goto exit; | |
136 | ||
137 | /* OK. For now, we presume we have a valid client. We now create the | |
138 | client structure, even though we cannot fill it completely yet. | |
139 | But it allows us to access lm75_{read,write}_value. */ | |
140 | if (!(data = kmalloc(sizeof(struct lm75_data), GFP_KERNEL))) { | |
141 | err = -ENOMEM; | |
142 | goto exit; | |
143 | } | |
144 | memset(data, 0, sizeof(struct lm75_data)); | |
145 | ||
146 | new_client = &data->client; | |
147 | i2c_set_clientdata(new_client, data); | |
148 | new_client->addr = address; | |
149 | new_client->adapter = adapter; | |
150 | new_client->driver = &lm75_driver; | |
151 | new_client->flags = 0; | |
152 | ||
153 | /* Now, we do the remaining detection. There is no identification- | |
154 | dedicated register so we have to rely on several tricks: | |
155 | unused bits, registers cycling over 8-address boundaries, | |
156 | addresses 0x04-0x07 returning the last read value. | |
157 | The cycling+unused addresses combination is not tested, | |
158 | since it would significantly slow the detection down and would | |
159 | hardly add any value. */ | |
160 | if (kind < 0) { | |
161 | int cur, conf, hyst, os; | |
162 | ||
163 | /* Unused addresses */ | |
164 | cur = i2c_smbus_read_word_data(new_client, 0); | |
165 | conf = i2c_smbus_read_byte_data(new_client, 1); | |
166 | hyst = i2c_smbus_read_word_data(new_client, 2); | |
167 | if (i2c_smbus_read_word_data(new_client, 4) != hyst | |
168 | || i2c_smbus_read_word_data(new_client, 5) != hyst | |
169 | || i2c_smbus_read_word_data(new_client, 6) != hyst | |
170 | || i2c_smbus_read_word_data(new_client, 7) != hyst) | |
171 | goto exit_free; | |
172 | os = i2c_smbus_read_word_data(new_client, 3); | |
173 | if (i2c_smbus_read_word_data(new_client, 4) != os | |
174 | || i2c_smbus_read_word_data(new_client, 5) != os | |
175 | || i2c_smbus_read_word_data(new_client, 6) != os | |
176 | || i2c_smbus_read_word_data(new_client, 7) != os) | |
177 | goto exit_free; | |
178 | ||
179 | /* Unused bits */ | |
180 | if (conf & 0xe0) | |
181 | goto exit_free; | |
182 | ||
183 | /* Addresses cycling */ | |
184 | for (i = 8; i < 0xff; i += 8) | |
185 | if (i2c_smbus_read_byte_data(new_client, i + 1) != conf | |
186 | || i2c_smbus_read_word_data(new_client, i + 2) != hyst | |
187 | || i2c_smbus_read_word_data(new_client, i + 3) != os) | |
188 | goto exit_free; | |
189 | } | |
190 | ||
191 | /* Determine the chip type - only one kind supported! */ | |
192 | if (kind <= 0) | |
193 | kind = lm75; | |
194 | ||
195 | if (kind == lm75) { | |
196 | name = "lm75"; | |
197 | } | |
198 | ||
199 | /* Fill in the remaining client fields and put it into the global list */ | |
200 | strlcpy(new_client->name, name, I2C_NAME_SIZE); | |
201 | data->valid = 0; | |
202 | init_MUTEX(&data->update_lock); | |
203 | ||
204 | /* Tell the I2C layer a new client has arrived */ | |
205 | if ((err = i2c_attach_client(new_client))) | |
206 | goto exit_free; | |
207 | ||
208 | /* Initialize the LM75 chip */ | |
209 | lm75_init_client(new_client); | |
210 | ||
211 | /* Register sysfs hooks */ | |
212 | device_create_file(&new_client->dev, &dev_attr_temp1_max); | |
213 | device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst); | |
214 | device_create_file(&new_client->dev, &dev_attr_temp1_input); | |
215 | ||
216 | return 0; | |
217 | ||
218 | exit_free: | |
219 | kfree(data); | |
220 | exit: | |
221 | return err; | |
222 | } | |
223 | ||
224 | static int lm75_detach_client(struct i2c_client *client) | |
225 | { | |
226 | i2c_detach_client(client); | |
227 | kfree(i2c_get_clientdata(client)); | |
228 | return 0; | |
229 | } | |
230 | ||
231 | /* All registers are word-sized, except for the configuration register. | |
232 | LM75 uses a high-byte first convention, which is exactly opposite to | |
233 | the usual practice. */ | |
234 | static int lm75_read_value(struct i2c_client *client, u8 reg) | |
235 | { | |
236 | if (reg == LM75_REG_CONF) | |
237 | return i2c_smbus_read_byte_data(client, reg); | |
238 | else | |
239 | return swab16(i2c_smbus_read_word_data(client, reg)); | |
240 | } | |
241 | ||
242 | /* All registers are word-sized, except for the configuration register. | |
243 | LM75 uses a high-byte first convention, which is exactly opposite to | |
244 | the usual practice. */ | |
245 | static int lm75_write_value(struct i2c_client *client, u8 reg, u16 value) | |
246 | { | |
247 | if (reg == LM75_REG_CONF) | |
248 | return i2c_smbus_write_byte_data(client, reg, value); | |
249 | else | |
250 | return i2c_smbus_write_word_data(client, reg, swab16(value)); | |
251 | } | |
252 | ||
253 | static void lm75_init_client(struct i2c_client *client) | |
254 | { | |
255 | /* Initialize the LM75 chip */ | |
256 | lm75_write_value(client, LM75_REG_CONF, 0); | |
257 | } | |
258 | ||
259 | static struct lm75_data *lm75_update_device(struct device *dev) | |
260 | { | |
261 | struct i2c_client *client = to_i2c_client(dev); | |
262 | struct lm75_data *data = i2c_get_clientdata(client); | |
263 | ||
264 | down(&data->update_lock); | |
265 | ||
266 | if (time_after(jiffies, data->last_updated + HZ + HZ / 2) | |
267 | || !data->valid) { | |
268 | dev_dbg(&client->dev, "Starting lm75 update\n"); | |
269 | ||
270 | data->temp_input = lm75_read_value(client, LM75_REG_TEMP); | |
271 | data->temp_max = lm75_read_value(client, LM75_REG_TEMP_OS); | |
272 | data->temp_hyst = lm75_read_value(client, LM75_REG_TEMP_HYST); | |
273 | data->last_updated = jiffies; | |
274 | data->valid = 1; | |
275 | } | |
276 | ||
277 | up(&data->update_lock); | |
278 | ||
279 | return data; | |
280 | } | |
281 | ||
282 | static int __init sensors_lm75_init(void) | |
283 | { | |
284 | return i2c_add_driver(&lm75_driver); | |
285 | } | |
286 | ||
287 | static void __exit sensors_lm75_exit(void) | |
288 | { | |
289 | i2c_del_driver(&lm75_driver); | |
290 | } | |
291 | ||
292 | MODULE_AUTHOR("Frodo Looijaard <frodol@dds.nl>"); | |
293 | MODULE_DESCRIPTION("LM75 driver"); | |
294 | MODULE_LICENSE("GPL"); | |
295 | ||
296 | module_init(sensors_lm75_init); | |
297 | module_exit(sensors_lm75_exit); |