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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/i2c/chips/lm77.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/lm77.c')
-rw-r--r--drivers/i2c/chips/lm77.c421
1 files changed, 421 insertions, 0 deletions
diff --git a/drivers/i2c/chips/lm77.c b/drivers/i2c/chips/lm77.c
new file mode 100644
index 000000000000..f56b7a37de75
--- /dev/null
+++ b/drivers/i2c/chips/lm77.c
@@ -0,0 +1,421 @@
1/*
2 lm77.c - Part of lm_sensors, Linux kernel modules for hardware
3 monitoring
4
5 Copyright (c) 2004 Andras BALI <drewie@freemail.hu>
6
7 Heavily based on lm75.c by Frodo Looijaard <frodol@dds.nl>. The LM77
8 is a temperature sensor and thermal window comparator with 0.5 deg
9 resolution made by National Semiconductor. Complete datasheet can be
10 obtained at their site:
11 http://www.national.com/pf/LM/LM77.html
12
13 This program is free software; you can redistribute it and/or modify
14 it under the terms of the GNU General Public License as published by
15 the Free Software Foundation; either version 2 of the License, or
16 (at your option) any later version.
17
18 This program is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU General Public License for more details.
22
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
26*/
27
28#include <linux/config.h>
29#include <linux/module.h>
30#include <linux/init.h>
31#include <linux/slab.h>
32#include <linux/jiffies.h>
33#include <linux/i2c.h>
34#include <linux/i2c-sensor.h>
35
36
37/* Addresses to scan */
38static unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b, I2C_CLIENT_END };
39static unsigned int normal_isa[] = { I2C_CLIENT_ISA_END };
40
41/* Insmod parameters */
42SENSORS_INSMOD_1(lm77);
43
44/* The LM77 registers */
45#define LM77_REG_TEMP 0x00
46#define LM77_REG_CONF 0x01
47#define LM77_REG_TEMP_HYST 0x02
48#define LM77_REG_TEMP_CRIT 0x03
49#define LM77_REG_TEMP_MIN 0x04
50#define LM77_REG_TEMP_MAX 0x05
51
52/* Each client has this additional data */
53struct lm77_data {
54 struct i2c_client client;
55 struct semaphore update_lock;
56 char valid;
57 unsigned long last_updated; /* In jiffies */
58 int temp_input; /* Temperatures */
59 int temp_crit;
60 int temp_min;
61 int temp_max;
62 int temp_hyst;
63 u8 alarms;
64};
65
66static int lm77_attach_adapter(struct i2c_adapter *adapter);
67static int lm77_detect(struct i2c_adapter *adapter, int address, int kind);
68static void lm77_init_client(struct i2c_client *client);
69static int lm77_detach_client(struct i2c_client *client);
70static u16 lm77_read_value(struct i2c_client *client, u8 reg);
71static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
72
73static struct lm77_data *lm77_update_device(struct device *dev);
74
75
76/* This is the driver that will be inserted */
77static struct i2c_driver lm77_driver = {
78 .owner = THIS_MODULE,
79 .name = "lm77",
80 .flags = I2C_DF_NOTIFY,
81 .attach_adapter = lm77_attach_adapter,
82 .detach_client = lm77_detach_client,
83};
84
85/* straight from the datasheet */
86#define LM77_TEMP_MIN (-55000)
87#define LM77_TEMP_MAX 125000
88
89/* In the temperature registers, the low 3 bits are not part of the
90 temperature values; they are the status bits. */
91static inline u16 LM77_TEMP_TO_REG(int temp)
92{
93 int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
94 return (u16)((ntemp / 500) * 8);
95}
96
97static inline int LM77_TEMP_FROM_REG(u16 reg)
98{
99 return ((int)reg / 8) * 500;
100}
101
102/* sysfs stuff */
103
104/* read routines for temperature limits */
105#define show(value) \
106static ssize_t show_##value(struct device *dev, char *buf) \
107{ \
108 struct lm77_data *data = lm77_update_device(dev); \
109 return sprintf(buf, "%d\n", data->value); \
110}
111
112show(temp_input);
113show(temp_crit);
114show(temp_min);
115show(temp_max);
116show(alarms);
117
118/* read routines for hysteresis values */
119static ssize_t show_temp_crit_hyst(struct device *dev, char *buf)
120{
121 struct lm77_data *data = lm77_update_device(dev);
122 return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
123}
124static ssize_t show_temp_min_hyst(struct device *dev, char *buf)
125{
126 struct lm77_data *data = lm77_update_device(dev);
127 return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
128}
129static ssize_t show_temp_max_hyst(struct device *dev, char *buf)
130{
131 struct lm77_data *data = lm77_update_device(dev);
132 return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
133}
134
135/* write routines */
136#define set(value, reg) \
137static ssize_t set_##value(struct device *dev, const char *buf, size_t count) \
138{ \
139 struct i2c_client *client = to_i2c_client(dev); \
140 struct lm77_data *data = i2c_get_clientdata(client); \
141 long val = simple_strtoul(buf, NULL, 10); \
142 \
143 down(&data->update_lock); \
144 data->value = val; \
145 lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
146 up(&data->update_lock); \
147 return count; \
148}
149
150set(temp_min, LM77_REG_TEMP_MIN);
151set(temp_max, LM77_REG_TEMP_MAX);
152
153/* hysteresis is stored as a relative value on the chip, so it has to be
154 converted first */
155static ssize_t set_temp_crit_hyst(struct device *dev, const char *buf, size_t count)
156{
157 struct i2c_client *client = to_i2c_client(dev);
158 struct lm77_data *data = i2c_get_clientdata(client);
159 unsigned long val = simple_strtoul(buf, NULL, 10);
160
161 down(&data->update_lock);
162 data->temp_hyst = data->temp_crit - val;
163 lm77_write_value(client, LM77_REG_TEMP_HYST,
164 LM77_TEMP_TO_REG(data->temp_hyst));
165 up(&data->update_lock);
166 return count;
167}
168
169/* preserve hysteresis when setting T_crit */
170static ssize_t set_temp_crit(struct device *dev, const char *buf, size_t count)
171{
172 struct i2c_client *client = to_i2c_client(dev);
173 struct lm77_data *data = i2c_get_clientdata(client);
174 long val = simple_strtoul(buf, NULL, 10);
175 int oldcrithyst;
176
177 down(&data->update_lock);
178 oldcrithyst = data->temp_crit - data->temp_hyst;
179 data->temp_crit = val;
180 data->temp_hyst = data->temp_crit - oldcrithyst;
181 lm77_write_value(client, LM77_REG_TEMP_CRIT,
182 LM77_TEMP_TO_REG(data->temp_crit));
183 lm77_write_value(client, LM77_REG_TEMP_HYST,
184 LM77_TEMP_TO_REG(data->temp_hyst));
185 up(&data->update_lock);
186 return count;
187}
188
189static DEVICE_ATTR(temp1_input, S_IRUGO,
190 show_temp_input, NULL);
191static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
192 show_temp_crit, set_temp_crit);
193static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
194 show_temp_min, set_temp_min);
195static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
196 show_temp_max, set_temp_max);
197
198static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
199 show_temp_crit_hyst, set_temp_crit_hyst);
200static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
201 show_temp_min_hyst, NULL);
202static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
203 show_temp_max_hyst, NULL);
204
205static DEVICE_ATTR(alarms, S_IRUGO,
206 show_alarms, NULL);
207
208static int lm77_attach_adapter(struct i2c_adapter *adapter)
209{
210 if (!(adapter->class & I2C_CLASS_HWMON))
211 return 0;
212 return i2c_detect(adapter, &addr_data, lm77_detect);
213}
214
215/* This function is called by i2c_detect */
216static int lm77_detect(struct i2c_adapter *adapter, int address, int kind)
217{
218 struct i2c_client *new_client;
219 struct lm77_data *data;
220 int err = 0;
221 const char *name = "";
222
223 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
224 I2C_FUNC_SMBUS_WORD_DATA))
225 goto exit;
226
227 /* OK. For now, we presume we have a valid client. We now create the
228 client structure, even though we cannot fill it completely yet.
229 But it allows us to access lm77_{read,write}_value. */
230 if (!(data = kmalloc(sizeof(struct lm77_data), GFP_KERNEL))) {
231 err = -ENOMEM;
232 goto exit;
233 }
234 memset(data, 0, sizeof(struct lm77_data));
235
236 new_client = &data->client;
237 i2c_set_clientdata(new_client, data);
238 new_client->addr = address;
239 new_client->adapter = adapter;
240 new_client->driver = &lm77_driver;
241 new_client->flags = 0;
242
243 /* Here comes the remaining detection. Since the LM77 has no
244 register dedicated to identification, we have to rely on the
245 following tricks:
246
247 1. the high 4 bits represent the sign and thus they should
248 always be the same
249 2. the high 3 bits are unused in the configuration register
250 3. addresses 0x06 and 0x07 return the last read value
251 4. registers cycling over 8-address boundaries
252
253 Word-sized registers are high-byte first. */
254 if (kind < 0) {
255 int i, cur, conf, hyst, crit, min, max;
256
257 /* addresses cycling */
258 cur = i2c_smbus_read_word_data(new_client, 0);
259 conf = i2c_smbus_read_byte_data(new_client, 1);
260 hyst = i2c_smbus_read_word_data(new_client, 2);
261 crit = i2c_smbus_read_word_data(new_client, 3);
262 min = i2c_smbus_read_word_data(new_client, 4);
263 max = i2c_smbus_read_word_data(new_client, 5);
264 for (i = 8; i <= 0xff; i += 8)
265 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
266 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
267 || i2c_smbus_read_word_data(new_client, i + 3) != crit
268 || i2c_smbus_read_word_data(new_client, i + 4) != min
269 || i2c_smbus_read_word_data(new_client, i + 5) != max)
270 goto exit_free;
271
272 /* sign bits */
273 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
274 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
275 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
276 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
277 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
278 goto exit_free;
279
280 /* unused bits */
281 if (conf & 0xe0)
282 goto exit_free;
283
284 /* 0x06 and 0x07 return the last read value */
285 cur = i2c_smbus_read_word_data(new_client, 0);
286 if (i2c_smbus_read_word_data(new_client, 6) != cur
287 || i2c_smbus_read_word_data(new_client, 7) != cur)
288 goto exit_free;
289 hyst = i2c_smbus_read_word_data(new_client, 2);
290 if (i2c_smbus_read_word_data(new_client, 6) != hyst
291 || i2c_smbus_read_word_data(new_client, 7) != hyst)
292 goto exit_free;
293 min = i2c_smbus_read_word_data(new_client, 4);
294 if (i2c_smbus_read_word_data(new_client, 6) != min
295 || i2c_smbus_read_word_data(new_client, 7) != min)
296 goto exit_free;
297
298 }
299
300 /* Determine the chip type - only one kind supported! */
301 if (kind <= 0)
302 kind = lm77;
303
304 if (kind == lm77) {
305 name = "lm77";
306 }
307
308 /* Fill in the remaining client fields and put it into the global list */
309 strlcpy(new_client->name, name, I2C_NAME_SIZE);
310 data->valid = 0;
311 init_MUTEX(&data->update_lock);
312
313 /* Tell the I2C layer a new client has arrived */
314 if ((err = i2c_attach_client(new_client)))
315 goto exit_free;
316
317 /* Initialize the LM77 chip */
318 lm77_init_client(new_client);
319
320 /* Register sysfs hooks */
321 device_create_file(&new_client->dev, &dev_attr_temp1_input);
322 device_create_file(&new_client->dev, &dev_attr_temp1_crit);
323 device_create_file(&new_client->dev, &dev_attr_temp1_min);
324 device_create_file(&new_client->dev, &dev_attr_temp1_max);
325 device_create_file(&new_client->dev, &dev_attr_temp1_crit_hyst);
326 device_create_file(&new_client->dev, &dev_attr_temp1_min_hyst);
327 device_create_file(&new_client->dev, &dev_attr_temp1_max_hyst);
328 device_create_file(&new_client->dev, &dev_attr_alarms);
329 return 0;
330
331exit_free:
332 kfree(data);
333exit:
334 return err;
335}
336
337static int lm77_detach_client(struct i2c_client *client)
338{
339 i2c_detach_client(client);
340 kfree(i2c_get_clientdata(client));
341 return 0;
342}
343
344/* All registers are word-sized, except for the configuration register.
345 The LM77 uses the high-byte first convention. */
346static u16 lm77_read_value(struct i2c_client *client, u8 reg)
347{
348 if (reg == LM77_REG_CONF)
349 return i2c_smbus_read_byte_data(client, reg);
350 else
351 return swab16(i2c_smbus_read_word_data(client, reg));
352}
353
354static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
355{
356 if (reg == LM77_REG_CONF)
357 return i2c_smbus_write_byte_data(client, reg, value);
358 else
359 return i2c_smbus_write_word_data(client, reg, swab16(value));
360}
361
362static void lm77_init_client(struct i2c_client *client)
363{
364 /* Initialize the LM77 chip - turn off shutdown mode */
365 int conf = lm77_read_value(client, LM77_REG_CONF);
366 if (conf & 1)
367 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
368}
369
370static struct lm77_data *lm77_update_device(struct device *dev)
371{
372 struct i2c_client *client = to_i2c_client(dev);
373 struct lm77_data *data = i2c_get_clientdata(client);
374
375 down(&data->update_lock);
376
377 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
378 || !data->valid) {
379 dev_dbg(&client->dev, "Starting lm77 update\n");
380 data->temp_input =
381 LM77_TEMP_FROM_REG(lm77_read_value(client,
382 LM77_REG_TEMP));
383 data->temp_hyst =
384 LM77_TEMP_FROM_REG(lm77_read_value(client,
385 LM77_REG_TEMP_HYST));
386 data->temp_crit =
387 LM77_TEMP_FROM_REG(lm77_read_value(client,
388 LM77_REG_TEMP_CRIT));
389 data->temp_min =
390 LM77_TEMP_FROM_REG(lm77_read_value(client,
391 LM77_REG_TEMP_MIN));
392 data->temp_max =
393 LM77_TEMP_FROM_REG(lm77_read_value(client,
394 LM77_REG_TEMP_MAX));
395 data->alarms =
396 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
397 data->last_updated = jiffies;
398 data->valid = 1;
399 }
400
401 up(&data->update_lock);
402
403 return data;
404}
405
406static int __init sensors_lm77_init(void)
407{
408 return i2c_add_driver(&lm77_driver);
409}
410
411static void __exit sensors_lm77_exit(void)
412{
413 i2c_del_driver(&lm77_driver);
414}
415
416MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
417MODULE_DESCRIPTION("LM77 driver");
418MODULE_LICENSE("GPL");
419
420module_init(sensors_lm77_init);
421module_exit(sensors_lm77_exit);