diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/i2c/chips/lm75.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/i2c/chips/lm75.c')
-rw-r--r-- | drivers/i2c/chips/lm75.c | 297 |
1 files changed, 297 insertions, 0 deletions
diff --git a/drivers/i2c/chips/lm75.c b/drivers/i2c/chips/lm75.c new file mode 100644 index 000000000000..0e86cc893981 --- /dev/null +++ b/drivers/i2c/chips/lm75.c | |||
@@ -0,0 +1,297 @@ | |||
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) \ | ||
78 | static ssize_t show_##value(struct device *dev, char *buf) \ | ||
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) \ | ||
88 | static ssize_t set_##value(struct device *dev, const char *buf, size_t count) \ | ||
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); | ||