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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/module.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/jiffies.h>
32#include <linux/i2c.h>
33#include <linux/hwmon.h>
34#include <linux/hwmon-sysfs.h>
35#include <linux/err.h>
36#include <linux/mutex.h>
37
38/* Addresses to scan */
39static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
40 I2C_CLIENT_END };
41
42/* The LM77 registers */
43#define LM77_REG_TEMP 0x00
44#define LM77_REG_CONF 0x01
45#define LM77_REG_TEMP_HYST 0x02
46#define LM77_REG_TEMP_CRIT 0x03
47#define LM77_REG_TEMP_MIN 0x04
48#define LM77_REG_TEMP_MAX 0x05
49
50/* Each client has this additional data */
51struct lm77_data {
52 struct device *hwmon_dev;
53 struct mutex update_lock;
54 char valid;
55 unsigned long last_updated; /* In jiffies */
56 int temp_input; /* Temperatures */
57 int temp_crit;
58 int temp_min;
59 int temp_max;
60 int temp_hyst;
61 u8 alarms;
62};
63
64static int lm77_probe(struct i2c_client *client,
65 const struct i2c_device_id *id);
66static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info);
67static void lm77_init_client(struct i2c_client *client);
68static int lm77_remove(struct i2c_client *client);
69static u16 lm77_read_value(struct i2c_client *client, u8 reg);
70static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
71
72static struct lm77_data *lm77_update_device(struct device *dev);
73
74
75static const struct i2c_device_id lm77_id[] = {
76 { "lm77", 0 },
77 { }
78};
79MODULE_DEVICE_TABLE(i2c, lm77_id);
80
81/* This is the driver that will be inserted */
82static struct i2c_driver lm77_driver = {
83 .class = I2C_CLASS_HWMON,
84 .driver = {
85 .name = "lm77",
86 },
87 .probe = lm77_probe,
88 .remove = lm77_remove,
89 .id_table = lm77_id,
90 .detect = lm77_detect,
91 .address_list = normal_i2c,
92};
93
94/* straight from the datasheet */
95#define LM77_TEMP_MIN (-55000)
96#define LM77_TEMP_MAX 125000
97
98/* In the temperature registers, the low 3 bits are not part of the
99 temperature values; they are the status bits. */
100static inline s16 LM77_TEMP_TO_REG(int temp)
101{
102 int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
103 return (ntemp / 500) * 8;
104}
105
106static inline int LM77_TEMP_FROM_REG(s16 reg)
107{
108 return (reg / 8) * 500;
109}
110
111/* sysfs stuff */
112
113/* read routines for temperature limits */
114#define show(value) \
115static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
116{ \
117 struct lm77_data *data = lm77_update_device(dev); \
118 return sprintf(buf, "%d\n", data->value); \
119}
120
121show(temp_input);
122show(temp_crit);
123show(temp_min);
124show(temp_max);
125
126/* read routines for hysteresis values */
127static ssize_t show_temp_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
128{
129 struct lm77_data *data = lm77_update_device(dev);
130 return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
131}
132static ssize_t show_temp_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
133{
134 struct lm77_data *data = lm77_update_device(dev);
135 return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
136}
137static ssize_t show_temp_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
138{
139 struct lm77_data *data = lm77_update_device(dev);
140 return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
141}
142
143/* write routines */
144#define set(value, reg) \
145static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
146{ \
147 struct i2c_client *client = to_i2c_client(dev); \
148 struct lm77_data *data = i2c_get_clientdata(client); \
149 long val = simple_strtol(buf, NULL, 10); \
150 \
151 mutex_lock(&data->update_lock); \
152 data->value = val; \
153 lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
154 mutex_unlock(&data->update_lock); \
155 return count; \
156}
157
158set(temp_min, LM77_REG_TEMP_MIN);
159set(temp_max, LM77_REG_TEMP_MAX);
160
161/* hysteresis is stored as a relative value on the chip, so it has to be
162 converted first */
163static ssize_t set_temp_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
164{
165 struct i2c_client *client = to_i2c_client(dev);
166 struct lm77_data *data = i2c_get_clientdata(client);
167 unsigned long val = simple_strtoul(buf, NULL, 10);
168
169 mutex_lock(&data->update_lock);
170 data->temp_hyst = data->temp_crit - val;
171 lm77_write_value(client, LM77_REG_TEMP_HYST,
172 LM77_TEMP_TO_REG(data->temp_hyst));
173 mutex_unlock(&data->update_lock);
174 return count;
175}
176
177/* preserve hysteresis when setting T_crit */
178static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
179{
180 struct i2c_client *client = to_i2c_client(dev);
181 struct lm77_data *data = i2c_get_clientdata(client);
182 long val = simple_strtoul(buf, NULL, 10);
183 int oldcrithyst;
184
185 mutex_lock(&data->update_lock);
186 oldcrithyst = data->temp_crit - data->temp_hyst;
187 data->temp_crit = val;
188 data->temp_hyst = data->temp_crit - oldcrithyst;
189 lm77_write_value(client, LM77_REG_TEMP_CRIT,
190 LM77_TEMP_TO_REG(data->temp_crit));
191 lm77_write_value(client, LM77_REG_TEMP_HYST,
192 LM77_TEMP_TO_REG(data->temp_hyst));
193 mutex_unlock(&data->update_lock);
194 return count;
195}
196
197static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
198 char *buf)
199{
200 int bitnr = to_sensor_dev_attr(attr)->index;
201 struct lm77_data *data = lm77_update_device(dev);
202 return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
203}
204
205static DEVICE_ATTR(temp1_input, S_IRUGO,
206 show_temp_input, NULL);
207static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
208 show_temp_crit, set_temp_crit);
209static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
210 show_temp_min, set_temp_min);
211static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
212 show_temp_max, set_temp_max);
213
214static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
215 show_temp_crit_hyst, set_temp_crit_hyst);
216static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
217 show_temp_min_hyst, NULL);
218static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
219 show_temp_max_hyst, NULL);
220
221static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
222static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
223static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
224
225static struct attribute *lm77_attributes[] = {
226 &dev_attr_temp1_input.attr,
227 &dev_attr_temp1_crit.attr,
228 &dev_attr_temp1_min.attr,
229 &dev_attr_temp1_max.attr,
230 &dev_attr_temp1_crit_hyst.attr,
231 &dev_attr_temp1_min_hyst.attr,
232 &dev_attr_temp1_max_hyst.attr,
233 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
234 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
235 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
236 NULL
237};
238
239static const struct attribute_group lm77_group = {
240 .attrs = lm77_attributes,
241};
242
243/* Return 0 if detection is successful, -ENODEV otherwise */
244static int lm77_detect(struct i2c_client *new_client,
245 struct i2c_board_info *info)
246{
247 struct i2c_adapter *adapter = new_client->adapter;
248 int i, cur, conf, hyst, crit, min, max;
249
250 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
251 I2C_FUNC_SMBUS_WORD_DATA))
252 return -ENODEV;
253
254 /* Here comes the remaining detection. Since the LM77 has no
255 register dedicated to identification, we have to rely on the
256 following tricks:
257
258 1. the high 4 bits represent the sign and thus they should
259 always be the same
260 2. the high 3 bits are unused in the configuration register
261 3. addresses 0x06 and 0x07 return the last read value
262 4. registers cycling over 8-address boundaries
263
264 Word-sized registers are high-byte first. */
265
266 /* addresses cycling */
267 cur = i2c_smbus_read_word_data(new_client, 0);
268 conf = i2c_smbus_read_byte_data(new_client, 1);
269 hyst = i2c_smbus_read_word_data(new_client, 2);
270 crit = i2c_smbus_read_word_data(new_client, 3);
271 min = i2c_smbus_read_word_data(new_client, 4);
272 max = i2c_smbus_read_word_data(new_client, 5);
273 for (i = 8; i <= 0xff; i += 8) {
274 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
275 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
276 || i2c_smbus_read_word_data(new_client, i + 3) != crit
277 || i2c_smbus_read_word_data(new_client, i + 4) != min
278 || i2c_smbus_read_word_data(new_client, i + 5) != max)
279 return -ENODEV;
280 }
281
282 /* sign bits */
283 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
284 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
285 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
286 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
287 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
288 return -ENODEV;
289
290 /* unused bits */
291 if (conf & 0xe0)
292 return -ENODEV;
293
294 /* 0x06 and 0x07 return the last read value */
295 cur = i2c_smbus_read_word_data(new_client, 0);
296 if (i2c_smbus_read_word_data(new_client, 6) != cur
297 || i2c_smbus_read_word_data(new_client, 7) != cur)
298 return -ENODEV;
299 hyst = i2c_smbus_read_word_data(new_client, 2);
300 if (i2c_smbus_read_word_data(new_client, 6) != hyst
301 || i2c_smbus_read_word_data(new_client, 7) != hyst)
302 return -ENODEV;
303 min = i2c_smbus_read_word_data(new_client, 4);
304 if (i2c_smbus_read_word_data(new_client, 6) != min
305 || i2c_smbus_read_word_data(new_client, 7) != min)
306 return -ENODEV;
307
308 strlcpy(info->type, "lm77", I2C_NAME_SIZE);
309
310 return 0;
311}
312
313static int lm77_probe(struct i2c_client *new_client,
314 const struct i2c_device_id *id)
315{
316 struct lm77_data *data;
317 int err;
318
319 data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL);
320 if (!data) {
321 err = -ENOMEM;
322 goto exit;
323 }
324
325 i2c_set_clientdata(new_client, data);
326 data->valid = 0;
327 mutex_init(&data->update_lock);
328
329 /* Initialize the LM77 chip */
330 lm77_init_client(new_client);
331
332 /* Register sysfs hooks */
333 if ((err = sysfs_create_group(&new_client->dev.kobj, &lm77_group)))
334 goto exit_free;
335
336 data->hwmon_dev = hwmon_device_register(&new_client->dev);
337 if (IS_ERR(data->hwmon_dev)) {
338 err = PTR_ERR(data->hwmon_dev);
339 goto exit_remove;
340 }
341
342 return 0;
343
344exit_remove:
345 sysfs_remove_group(&new_client->dev.kobj, &lm77_group);
346exit_free:
347 kfree(data);
348exit:
349 return err;
350}
351
352static int lm77_remove(struct i2c_client *client)
353{
354 struct lm77_data *data = i2c_get_clientdata(client);
355 hwmon_device_unregister(data->hwmon_dev);
356 sysfs_remove_group(&client->dev.kobj, &lm77_group);
357 kfree(data);
358 return 0;
359}
360
361/* All registers are word-sized, except for the configuration register.
362 The LM77 uses the high-byte first convention. */
363static u16 lm77_read_value(struct i2c_client *client, u8 reg)
364{
365 if (reg == LM77_REG_CONF)
366 return i2c_smbus_read_byte_data(client, reg);
367 else
368 return swab16(i2c_smbus_read_word_data(client, reg));
369}
370
371static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
372{
373 if (reg == LM77_REG_CONF)
374 return i2c_smbus_write_byte_data(client, reg, value);
375 else
376 return i2c_smbus_write_word_data(client, reg, swab16(value));
377}
378
379static void lm77_init_client(struct i2c_client *client)
380{
381 /* Initialize the LM77 chip - turn off shutdown mode */
382 int conf = lm77_read_value(client, LM77_REG_CONF);
383 if (conf & 1)
384 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
385}
386
387static struct lm77_data *lm77_update_device(struct device *dev)
388{
389 struct i2c_client *client = to_i2c_client(dev);
390 struct lm77_data *data = i2c_get_clientdata(client);
391
392 mutex_lock(&data->update_lock);
393
394 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
395 || !data->valid) {
396 dev_dbg(&client->dev, "Starting lm77 update\n");
397 data->temp_input =
398 LM77_TEMP_FROM_REG(lm77_read_value(client,
399 LM77_REG_TEMP));
400 data->temp_hyst =
401 LM77_TEMP_FROM_REG(lm77_read_value(client,
402 LM77_REG_TEMP_HYST));
403 data->temp_crit =
404 LM77_TEMP_FROM_REG(lm77_read_value(client,
405 LM77_REG_TEMP_CRIT));
406 data->temp_min =
407 LM77_TEMP_FROM_REG(lm77_read_value(client,
408 LM77_REG_TEMP_MIN));
409 data->temp_max =
410 LM77_TEMP_FROM_REG(lm77_read_value(client,
411 LM77_REG_TEMP_MAX));
412 data->alarms =
413 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
414 data->last_updated = jiffies;
415 data->valid = 1;
416 }
417
418 mutex_unlock(&data->update_lock);
419
420 return data;
421}
422
423static int __init sensors_lm77_init(void)
424{
425 return i2c_add_driver(&lm77_driver);
426}
427
428static void __exit sensors_lm77_exit(void)
429{
430 i2c_del_driver(&lm77_driver);
431}
432
433MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
434MODULE_DESCRIPTION("LM77 driver");
435MODULE_LICENSE("GPL");
436
437module_init(sensors_lm77_init);
438module_exit(sensors_lm77_exit);
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/module.h>
29#include <linux/init.h>
30#include <linux/slab.h>
31#include <linux/jiffies.h>
32#include <linux/i2c.h>
33#include <linux/hwmon.h>
34#include <linux/hwmon-sysfs.h>
35#include <linux/err.h>
36#include <linux/mutex.h>
37
38/* Addresses to scan */
39static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
40 I2C_CLIENT_END };
41
42/* The LM77 registers */
43#define LM77_REG_TEMP 0x00
44#define LM77_REG_CONF 0x01
45#define LM77_REG_TEMP_HYST 0x02
46#define LM77_REG_TEMP_CRIT 0x03
47#define LM77_REG_TEMP_MIN 0x04
48#define LM77_REG_TEMP_MAX 0x05
49
50/* Each client has this additional data */
51struct lm77_data {
52 struct device *hwmon_dev;
53 struct mutex update_lock;
54 char valid;
55 unsigned long last_updated; /* In jiffies */
56 int temp_input; /* Temperatures */
57 int temp_crit;
58 int temp_min;
59 int temp_max;
60 int temp_hyst;
61 u8 alarms;
62};
63
64static int lm77_probe(struct i2c_client *client,
65 const struct i2c_device_id *id);
66static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info);
67static void lm77_init_client(struct i2c_client *client);
68static int lm77_remove(struct i2c_client *client);
69static u16 lm77_read_value(struct i2c_client *client, u8 reg);
70static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value);
71
72static struct lm77_data *lm77_update_device(struct device *dev);
73
74
75static const struct i2c_device_id lm77_id[] = {
76 { "lm77", 0 },
77 { }
78};
79MODULE_DEVICE_TABLE(i2c, lm77_id);
80
81/* This is the driver that will be inserted */
82static struct i2c_driver lm77_driver = {
83 .class = I2C_CLASS_HWMON,
84 .driver = {
85 .name = "lm77",
86 },
87 .probe = lm77_probe,
88 .remove = lm77_remove,
89 .id_table = lm77_id,
90 .detect = lm77_detect,
91 .address_list = normal_i2c,
92};
93
94/* straight from the datasheet */
95#define LM77_TEMP_MIN (-55000)
96#define LM77_TEMP_MAX 125000
97
98/*
99 * In the temperature registers, the low 3 bits are not part of the
100 * temperature values; they are the status bits.
101 */
102static inline s16 LM77_TEMP_TO_REG(int temp)
103{
104 int ntemp = SENSORS_LIMIT(temp, LM77_TEMP_MIN, LM77_TEMP_MAX);
105 return (ntemp / 500) * 8;
106}
107
108static inline int LM77_TEMP_FROM_REG(s16 reg)
109{
110 return (reg / 8) * 500;
111}
112
113/* sysfs stuff */
114
115/* read routines for temperature limits */
116#define show(value) \
117static ssize_t show_##value(struct device *dev, \
118 struct device_attribute *attr, \
119 char *buf) \
120{ \
121 struct lm77_data *data = lm77_update_device(dev); \
122 return sprintf(buf, "%d\n", data->value); \
123}
124
125show(temp_input);
126show(temp_crit);
127show(temp_min);
128show(temp_max);
129
130/* read routines for hysteresis values */
131static ssize_t show_temp_crit_hyst(struct device *dev,
132 struct device_attribute *attr, char *buf)
133{
134 struct lm77_data *data = lm77_update_device(dev);
135 return sprintf(buf, "%d\n", data->temp_crit - data->temp_hyst);
136}
137static ssize_t show_temp_min_hyst(struct device *dev,
138 struct device_attribute *attr, char *buf)
139{
140 struct lm77_data *data = lm77_update_device(dev);
141 return sprintf(buf, "%d\n", data->temp_min + data->temp_hyst);
142}
143static ssize_t show_temp_max_hyst(struct device *dev,
144 struct device_attribute *attr, char *buf)
145{
146 struct lm77_data *data = lm77_update_device(dev);
147 return sprintf(buf, "%d\n", data->temp_max - data->temp_hyst);
148}
149
150/* write routines */
151#define set(value, reg) \
152static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
153 const char *buf, size_t count) \
154{ \
155 struct i2c_client *client = to_i2c_client(dev); \
156 struct lm77_data *data = i2c_get_clientdata(client); \
157 long val; \
158 int err = kstrtol(buf, 10, &val); \
159 if (err) \
160 return err; \
161 \
162 mutex_lock(&data->update_lock); \
163 data->value = val; \
164 lm77_write_value(client, reg, LM77_TEMP_TO_REG(data->value)); \
165 mutex_unlock(&data->update_lock); \
166 return count; \
167}
168
169set(temp_min, LM77_REG_TEMP_MIN);
170set(temp_max, LM77_REG_TEMP_MAX);
171
172/*
173 * hysteresis is stored as a relative value on the chip, so it has to be
174 * converted first
175 */
176static ssize_t set_temp_crit_hyst(struct device *dev,
177 struct device_attribute *attr,
178 const char *buf, size_t count)
179{
180 struct i2c_client *client = to_i2c_client(dev);
181 struct lm77_data *data = i2c_get_clientdata(client);
182 unsigned long val;
183 int err;
184
185 err = kstrtoul(buf, 10, &val);
186 if (err)
187 return err;
188
189 mutex_lock(&data->update_lock);
190 data->temp_hyst = data->temp_crit - val;
191 lm77_write_value(client, LM77_REG_TEMP_HYST,
192 LM77_TEMP_TO_REG(data->temp_hyst));
193 mutex_unlock(&data->update_lock);
194 return count;
195}
196
197/* preserve hysteresis when setting T_crit */
198static ssize_t set_temp_crit(struct device *dev, struct device_attribute *attr,
199 const char *buf, size_t count)
200{
201 struct i2c_client *client = to_i2c_client(dev);
202 struct lm77_data *data = i2c_get_clientdata(client);
203 int oldcrithyst;
204 unsigned long val;
205 int err;
206
207 err = kstrtoul(buf, 10, &val);
208 if (err)
209 return err;
210
211 mutex_lock(&data->update_lock);
212 oldcrithyst = data->temp_crit - data->temp_hyst;
213 data->temp_crit = val;
214 data->temp_hyst = data->temp_crit - oldcrithyst;
215 lm77_write_value(client, LM77_REG_TEMP_CRIT,
216 LM77_TEMP_TO_REG(data->temp_crit));
217 lm77_write_value(client, LM77_REG_TEMP_HYST,
218 LM77_TEMP_TO_REG(data->temp_hyst));
219 mutex_unlock(&data->update_lock);
220 return count;
221}
222
223static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
224 char *buf)
225{
226 int bitnr = to_sensor_dev_attr(attr)->index;
227 struct lm77_data *data = lm77_update_device(dev);
228 return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
229}
230
231static DEVICE_ATTR(temp1_input, S_IRUGO,
232 show_temp_input, NULL);
233static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
234 show_temp_crit, set_temp_crit);
235static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
236 show_temp_min, set_temp_min);
237static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
238 show_temp_max, set_temp_max);
239
240static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
241 show_temp_crit_hyst, set_temp_crit_hyst);
242static DEVICE_ATTR(temp1_min_hyst, S_IRUGO,
243 show_temp_min_hyst, NULL);
244static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
245 show_temp_max_hyst, NULL);
246
247static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
248static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
249static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
250
251static struct attribute *lm77_attributes[] = {
252 &dev_attr_temp1_input.attr,
253 &dev_attr_temp1_crit.attr,
254 &dev_attr_temp1_min.attr,
255 &dev_attr_temp1_max.attr,
256 &dev_attr_temp1_crit_hyst.attr,
257 &dev_attr_temp1_min_hyst.attr,
258 &dev_attr_temp1_max_hyst.attr,
259 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
260 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
261 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
262 NULL
263};
264
265static const struct attribute_group lm77_group = {
266 .attrs = lm77_attributes,
267};
268
269/* Return 0 if detection is successful, -ENODEV otherwise */
270static int lm77_detect(struct i2c_client *new_client,
271 struct i2c_board_info *info)
272{
273 struct i2c_adapter *adapter = new_client->adapter;
274 int i, cur, conf, hyst, crit, min, max;
275
276 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
277 I2C_FUNC_SMBUS_WORD_DATA))
278 return -ENODEV;
279
280 /*
281 * Here comes the remaining detection. Since the LM77 has no
282 * register dedicated to identification, we have to rely on the
283 * following tricks:
284 *
285 * 1. the high 4 bits represent the sign and thus they should
286 * always be the same
287 * 2. the high 3 bits are unused in the configuration register
288 * 3. addresses 0x06 and 0x07 return the last read value
289 * 4. registers cycling over 8-address boundaries
290 *
291 * Word-sized registers are high-byte first.
292 */
293
294 /* addresses cycling */
295 cur = i2c_smbus_read_word_data(new_client, 0);
296 conf = i2c_smbus_read_byte_data(new_client, 1);
297 hyst = i2c_smbus_read_word_data(new_client, 2);
298 crit = i2c_smbus_read_word_data(new_client, 3);
299 min = i2c_smbus_read_word_data(new_client, 4);
300 max = i2c_smbus_read_word_data(new_client, 5);
301 for (i = 8; i <= 0xff; i += 8) {
302 if (i2c_smbus_read_byte_data(new_client, i + 1) != conf
303 || i2c_smbus_read_word_data(new_client, i + 2) != hyst
304 || i2c_smbus_read_word_data(new_client, i + 3) != crit
305 || i2c_smbus_read_word_data(new_client, i + 4) != min
306 || i2c_smbus_read_word_data(new_client, i + 5) != max)
307 return -ENODEV;
308 }
309
310 /* sign bits */
311 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
312 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
313 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
314 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
315 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
316 return -ENODEV;
317
318 /* unused bits */
319 if (conf & 0xe0)
320 return -ENODEV;
321
322 /* 0x06 and 0x07 return the last read value */
323 cur = i2c_smbus_read_word_data(new_client, 0);
324 if (i2c_smbus_read_word_data(new_client, 6) != cur
325 || i2c_smbus_read_word_data(new_client, 7) != cur)
326 return -ENODEV;
327 hyst = i2c_smbus_read_word_data(new_client, 2);
328 if (i2c_smbus_read_word_data(new_client, 6) != hyst
329 || i2c_smbus_read_word_data(new_client, 7) != hyst)
330 return -ENODEV;
331 min = i2c_smbus_read_word_data(new_client, 4);
332 if (i2c_smbus_read_word_data(new_client, 6) != min
333 || i2c_smbus_read_word_data(new_client, 7) != min)
334 return -ENODEV;
335
336 strlcpy(info->type, "lm77", I2C_NAME_SIZE);
337
338 return 0;
339}
340
341static int lm77_probe(struct i2c_client *new_client,
342 const struct i2c_device_id *id)
343{
344 struct lm77_data *data;
345 int err;
346
347 data = kzalloc(sizeof(struct lm77_data), GFP_KERNEL);
348 if (!data) {
349 err = -ENOMEM;
350 goto exit;
351 }
352
353 i2c_set_clientdata(new_client, data);
354 data->valid = 0;
355 mutex_init(&data->update_lock);
356
357 /* Initialize the LM77 chip */
358 lm77_init_client(new_client);
359
360 /* Register sysfs hooks */
361 err = sysfs_create_group(&new_client->dev.kobj, &lm77_group);
362 if (err)
363 goto exit_free;
364
365 data->hwmon_dev = hwmon_device_register(&new_client->dev);
366 if (IS_ERR(data->hwmon_dev)) {
367 err = PTR_ERR(data->hwmon_dev);
368 goto exit_remove;
369 }
370
371 return 0;
372
373exit_remove:
374 sysfs_remove_group(&new_client->dev.kobj, &lm77_group);
375exit_free:
376 kfree(data);
377exit:
378 return err;
379}
380
381static int lm77_remove(struct i2c_client *client)
382{
383 struct lm77_data *data = i2c_get_clientdata(client);
384 hwmon_device_unregister(data->hwmon_dev);
385 sysfs_remove_group(&client->dev.kobj, &lm77_group);
386 kfree(data);
387 return 0;
388}
389
390/*
391 * All registers are word-sized, except for the configuration register.
392 * The LM77 uses the high-byte first convention.
393 */
394static u16 lm77_read_value(struct i2c_client *client, u8 reg)
395{
396 if (reg == LM77_REG_CONF)
397 return i2c_smbus_read_byte_data(client, reg);
398 else
399 return i2c_smbus_read_word_swapped(client, reg);
400}
401
402static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
403{
404 if (reg == LM77_REG_CONF)
405 return i2c_smbus_write_byte_data(client, reg, value);
406 else
407 return i2c_smbus_write_word_swapped(client, reg, value);
408}
409
410static void lm77_init_client(struct i2c_client *client)
411{
412 /* Initialize the LM77 chip - turn off shutdown mode */
413 int conf = lm77_read_value(client, LM77_REG_CONF);
414 if (conf & 1)
415 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
416}
417
418static struct lm77_data *lm77_update_device(struct device *dev)
419{
420 struct i2c_client *client = to_i2c_client(dev);
421 struct lm77_data *data = i2c_get_clientdata(client);
422
423 mutex_lock(&data->update_lock);
424
425 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
426 || !data->valid) {
427 dev_dbg(&client->dev, "Starting lm77 update\n");
428 data->temp_input =
429 LM77_TEMP_FROM_REG(lm77_read_value(client,
430 LM77_REG_TEMP));
431 data->temp_hyst =
432 LM77_TEMP_FROM_REG(lm77_read_value(client,
433 LM77_REG_TEMP_HYST));
434 data->temp_crit =
435 LM77_TEMP_FROM_REG(lm77_read_value(client,
436 LM77_REG_TEMP_CRIT));
437 data->temp_min =
438 LM77_TEMP_FROM_REG(lm77_read_value(client,
439 LM77_REG_TEMP_MIN));
440 data->temp_max =
441 LM77_TEMP_FROM_REG(lm77_read_value(client,
442 LM77_REG_TEMP_MAX));
443 data->alarms =
444 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
445 data->last_updated = jiffies;
446 data->valid = 1;
447 }
448
449 mutex_unlock(&data->update_lock);
450
451 return data;
452}
453
454module_i2c_driver(lm77_driver);
455
456MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
457MODULE_DESCRIPTION("LM77 driver");
458MODULE_LICENSE("GPL");