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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
39static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
40 I2C_CLIENT_END };
41
42
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
51struct lm77_data {
52 struct device *hwmon_dev;
53 struct mutex update_lock;
54 char valid;
55 unsigned long last_updated;
56 int temp_input;
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
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
95#define LM77_TEMP_MIN (-55000)
96#define LM77_TEMP_MAX 125000
97
98
99
100
101
102static inline s16 LM77_TEMP_TO_REG(int temp)
103{
104 int ntemp = clamp_val(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
114
115
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
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
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
174
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
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
270static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info)
271{
272 struct i2c_adapter *adapter = client->adapter;
273 int i, cur, conf, hyst, crit, min, max;
274
275 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
276 I2C_FUNC_SMBUS_WORD_DATA))
277 return -ENODEV;
278
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293
294 cur = i2c_smbus_read_word_data(client, 0);
295 conf = i2c_smbus_read_byte_data(client, 1);
296 hyst = i2c_smbus_read_word_data(client, 2);
297 crit = i2c_smbus_read_word_data(client, 3);
298 min = i2c_smbus_read_word_data(client, 4);
299 max = i2c_smbus_read_word_data(client, 5);
300 for (i = 8; i <= 0xff; i += 8) {
301 if (i2c_smbus_read_byte_data(client, i + 1) != conf
302 || i2c_smbus_read_word_data(client, i + 2) != hyst
303 || i2c_smbus_read_word_data(client, i + 3) != crit
304 || i2c_smbus_read_word_data(client, i + 4) != min
305 || i2c_smbus_read_word_data(client, i + 5) != max)
306 return -ENODEV;
307 }
308
309
310 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
311 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
312 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
313 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
314 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
315 return -ENODEV;
316
317
318 if (conf & 0xe0)
319 return -ENODEV;
320
321
322 cur = i2c_smbus_read_word_data(client, 0);
323 if (i2c_smbus_read_word_data(client, 6) != cur
324 || i2c_smbus_read_word_data(client, 7) != cur)
325 return -ENODEV;
326 hyst = i2c_smbus_read_word_data(client, 2);
327 if (i2c_smbus_read_word_data(client, 6) != hyst
328 || i2c_smbus_read_word_data(client, 7) != hyst)
329 return -ENODEV;
330 min = i2c_smbus_read_word_data(client, 4);
331 if (i2c_smbus_read_word_data(client, 6) != min
332 || i2c_smbus_read_word_data(client, 7) != min)
333 return -ENODEV;
334
335 strlcpy(info->type, "lm77", I2C_NAME_SIZE);
336
337 return 0;
338}
339
340static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id)
341{
342 struct device *dev = &client->dev;
343 struct lm77_data *data;
344 int err;
345
346 data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
347 if (!data)
348 return -ENOMEM;
349
350 i2c_set_clientdata(client, data);
351 data->valid = 0;
352 mutex_init(&data->update_lock);
353
354
355 lm77_init_client(client);
356
357
358 err = sysfs_create_group(&dev->kobj, &lm77_group);
359 if (err)
360 return err;
361
362 data->hwmon_dev = hwmon_device_register(dev);
363 if (IS_ERR(data->hwmon_dev)) {
364 err = PTR_ERR(data->hwmon_dev);
365 goto exit_remove;
366 }
367
368 return 0;
369
370exit_remove:
371 sysfs_remove_group(&dev->kobj, &lm77_group);
372 return err;
373}
374
375static int lm77_remove(struct i2c_client *client)
376{
377 struct lm77_data *data = i2c_get_clientdata(client);
378 hwmon_device_unregister(data->hwmon_dev);
379 sysfs_remove_group(&client->dev.kobj, &lm77_group);
380 return 0;
381}
382
383
384
385
386
387static u16 lm77_read_value(struct i2c_client *client, u8 reg)
388{
389 if (reg == LM77_REG_CONF)
390 return i2c_smbus_read_byte_data(client, reg);
391 else
392 return i2c_smbus_read_word_swapped(client, reg);
393}
394
395static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
396{
397 if (reg == LM77_REG_CONF)
398 return i2c_smbus_write_byte_data(client, reg, value);
399 else
400 return i2c_smbus_write_word_swapped(client, reg, value);
401}
402
403static void lm77_init_client(struct i2c_client *client)
404{
405
406 int conf = lm77_read_value(client, LM77_REG_CONF);
407 if (conf & 1)
408 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
409}
410
411static struct lm77_data *lm77_update_device(struct device *dev)
412{
413 struct i2c_client *client = to_i2c_client(dev);
414 struct lm77_data *data = i2c_get_clientdata(client);
415
416 mutex_lock(&data->update_lock);
417
418 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
419 || !data->valid) {
420 dev_dbg(&client->dev, "Starting lm77 update\n");
421 data->temp_input =
422 LM77_TEMP_FROM_REG(lm77_read_value(client,
423 LM77_REG_TEMP));
424 data->temp_hyst =
425 LM77_TEMP_FROM_REG(lm77_read_value(client,
426 LM77_REG_TEMP_HYST));
427 data->temp_crit =
428 LM77_TEMP_FROM_REG(lm77_read_value(client,
429 LM77_REG_TEMP_CRIT));
430 data->temp_min =
431 LM77_TEMP_FROM_REG(lm77_read_value(client,
432 LM77_REG_TEMP_MIN));
433 data->temp_max =
434 LM77_TEMP_FROM_REG(lm77_read_value(client,
435 LM77_REG_TEMP_MAX));
436 data->alarms =
437 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
438 data->last_updated = jiffies;
439 data->valid = 1;
440 }
441
442 mutex_unlock(&data->update_lock);
443
444 return data;
445}
446
447module_i2c_driver(lm77_driver);
448
449MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
450MODULE_DESCRIPTION("LM77 driver");
451MODULE_LICENSE("GPL");
452