Loading...
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
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/jiffies.h>
28#include <linux/i2c.h>
29#include <linux/hwmon.h>
30#include <linux/hwmon-sysfs.h>
31#include <linux/err.h>
32#include <linux/mutex.h>
33
34/* Addresses to scan */
35static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
36 I2C_CLIENT_END };
37
38/* The LM77 registers */
39#define LM77_REG_TEMP 0x00
40#define LM77_REG_CONF 0x01
41#define LM77_REG_TEMP_HYST 0x02
42#define LM77_REG_TEMP_CRIT 0x03
43#define LM77_REG_TEMP_MIN 0x04
44#define LM77_REG_TEMP_MAX 0x05
45
46enum temp_index {
47 t_input = 0,
48 t_crit,
49 t_min,
50 t_max,
51 t_hyst,
52 t_num_temp
53};
54
55static const u8 temp_regs[t_num_temp] = {
56 [t_input] = LM77_REG_TEMP,
57 [t_min] = LM77_REG_TEMP_MIN,
58 [t_max] = LM77_REG_TEMP_MAX,
59 [t_crit] = LM77_REG_TEMP_CRIT,
60 [t_hyst] = LM77_REG_TEMP_HYST,
61};
62
63/* Each client has this additional data */
64struct lm77_data {
65 struct i2c_client *client;
66 struct mutex update_lock;
67 char valid;
68 unsigned long last_updated; /* In jiffies */
69 int temp[t_num_temp]; /* index using temp_index */
70 u8 alarms;
71};
72
73/* straight from the datasheet */
74#define LM77_TEMP_MIN (-55000)
75#define LM77_TEMP_MAX 125000
76
77/*
78 * In the temperature registers, the low 3 bits are not part of the
79 * temperature values; they are the status bits.
80 */
81static inline s16 LM77_TEMP_TO_REG(int temp)
82{
83 return (temp / 500) * 8;
84}
85
86static inline int LM77_TEMP_FROM_REG(s16 reg)
87{
88 return (reg / 8) * 500;
89}
90
91/*
92 * All registers are word-sized, except for the configuration register.
93 * The LM77 uses the high-byte first convention.
94 */
95static u16 lm77_read_value(struct i2c_client *client, u8 reg)
96{
97 if (reg == LM77_REG_CONF)
98 return i2c_smbus_read_byte_data(client, reg);
99 else
100 return i2c_smbus_read_word_swapped(client, reg);
101}
102
103static int lm77_write_value(struct i2c_client *client, u8 reg, u16 value)
104{
105 if (reg == LM77_REG_CONF)
106 return i2c_smbus_write_byte_data(client, reg, value);
107 else
108 return i2c_smbus_write_word_swapped(client, reg, value);
109}
110
111static struct lm77_data *lm77_update_device(struct device *dev)
112{
113 struct lm77_data *data = dev_get_drvdata(dev);
114 struct i2c_client *client = data->client;
115 int i;
116
117 mutex_lock(&data->update_lock);
118
119 if (time_after(jiffies, data->last_updated + HZ + HZ / 2)
120 || !data->valid) {
121 dev_dbg(&client->dev, "Starting lm77 update\n");
122 for (i = 0; i < t_num_temp; i++) {
123 data->temp[i] =
124 LM77_TEMP_FROM_REG(lm77_read_value(client,
125 temp_regs[i]));
126 }
127 data->alarms =
128 lm77_read_value(client, LM77_REG_TEMP) & 0x0007;
129 data->last_updated = jiffies;
130 data->valid = 1;
131 }
132
133 mutex_unlock(&data->update_lock);
134
135 return data;
136}
137
138/* sysfs stuff */
139
140static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
141 char *buf)
142{
143 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
144 struct lm77_data *data = lm77_update_device(dev);
145
146 return sprintf(buf, "%d\n", data->temp[attr->index]);
147}
148
149static ssize_t show_temp_hyst(struct device *dev,
150 struct device_attribute *devattr, char *buf)
151{
152 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
153 struct lm77_data *data = lm77_update_device(dev);
154 int nr = attr->index;
155 int temp;
156
157 temp = nr == t_min ? data->temp[nr] + data->temp[t_hyst] :
158 data->temp[nr] - data->temp[t_hyst];
159
160 return sprintf(buf, "%d\n", temp);
161}
162
163static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
164 const char *buf, size_t count)
165{
166 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
167 struct lm77_data *data = dev_get_drvdata(dev);
168 struct i2c_client *client = data->client;
169 int nr = attr->index;
170 long val;
171 int err;
172
173 err = kstrtol(buf, 10, &val);
174 if (err)
175 return err;
176
177 val = clamp_val(val, LM77_TEMP_MIN, LM77_TEMP_MAX);
178 mutex_lock(&data->update_lock);
179 data->temp[nr] = val;
180 lm77_write_value(client, temp_regs[nr], LM77_TEMP_TO_REG(val));
181 mutex_unlock(&data->update_lock);
182 return count;
183}
184
185/*
186 * hysteresis is stored as a relative value on the chip, so it has to be
187 * converted first.
188 */
189static ssize_t set_temp_hyst(struct device *dev,
190 struct device_attribute *devattr,
191 const char *buf, size_t count)
192{
193 struct lm77_data *data = dev_get_drvdata(dev);
194 struct i2c_client *client = data->client;
195 long val;
196 int err;
197
198 err = kstrtol(buf, 10, &val);
199 if (err)
200 return err;
201
202 mutex_lock(&data->update_lock);
203 val = clamp_val(data->temp[t_crit] - val, LM77_TEMP_MIN, LM77_TEMP_MAX);
204 data->temp[t_hyst] = val;
205 lm77_write_value(client, LM77_REG_TEMP_HYST,
206 LM77_TEMP_TO_REG(data->temp[t_hyst]));
207 mutex_unlock(&data->update_lock);
208 return count;
209}
210
211static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
212 char *buf)
213{
214 int bitnr = to_sensor_dev_attr(attr)->index;
215 struct lm77_data *data = lm77_update_device(dev);
216 return sprintf(buf, "%u\n", (data->alarms >> bitnr) & 1);
217}
218
219static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input);
220static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp, set_temp,
221 t_crit);
222static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp,
223 t_min);
224static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp,
225 t_max);
226
227static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst,
228 set_temp_hyst, t_crit);
229static SENSOR_DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp_hyst, NULL, t_min);
230static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max);
231
232static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
233static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
234static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
235
236static struct attribute *lm77_attrs[] = {
237 &sensor_dev_attr_temp1_input.dev_attr.attr,
238 &sensor_dev_attr_temp1_crit.dev_attr.attr,
239 &sensor_dev_attr_temp1_min.dev_attr.attr,
240 &sensor_dev_attr_temp1_max.dev_attr.attr,
241 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
242 &sensor_dev_attr_temp1_min_hyst.dev_attr.attr,
243 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
244 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
245 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
246 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
247 NULL
248};
249ATTRIBUTE_GROUPS(lm77);
250
251/* Return 0 if detection is successful, -ENODEV otherwise */
252static int lm77_detect(struct i2c_client *client, struct i2c_board_info *info)
253{
254 struct i2c_adapter *adapter = client->adapter;
255 int i, cur, conf, hyst, crit, min, max;
256
257 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
258 I2C_FUNC_SMBUS_WORD_DATA))
259 return -ENODEV;
260
261 /*
262 * Here comes the remaining detection. Since the LM77 has no
263 * register dedicated to identification, we have to rely on the
264 * following tricks:
265 *
266 * 1. the high 4 bits represent the sign and thus they should
267 * always be the same
268 * 2. the high 3 bits are unused in the configuration register
269 * 3. addresses 0x06 and 0x07 return the last read value
270 * 4. registers cycling over 8-address boundaries
271 *
272 * Word-sized registers are high-byte first.
273 */
274
275 /* addresses cycling */
276 cur = i2c_smbus_read_word_data(client, 0);
277 conf = i2c_smbus_read_byte_data(client, 1);
278 hyst = i2c_smbus_read_word_data(client, 2);
279 crit = i2c_smbus_read_word_data(client, 3);
280 min = i2c_smbus_read_word_data(client, 4);
281 max = i2c_smbus_read_word_data(client, 5);
282 for (i = 8; i <= 0xff; i += 8) {
283 if (i2c_smbus_read_byte_data(client, i + 1) != conf
284 || i2c_smbus_read_word_data(client, i + 2) != hyst
285 || i2c_smbus_read_word_data(client, i + 3) != crit
286 || i2c_smbus_read_word_data(client, i + 4) != min
287 || i2c_smbus_read_word_data(client, i + 5) != max)
288 return -ENODEV;
289 }
290
291 /* sign bits */
292 if (((cur & 0x00f0) != 0xf0 && (cur & 0x00f0) != 0x0)
293 || ((hyst & 0x00f0) != 0xf0 && (hyst & 0x00f0) != 0x0)
294 || ((crit & 0x00f0) != 0xf0 && (crit & 0x00f0) != 0x0)
295 || ((min & 0x00f0) != 0xf0 && (min & 0x00f0) != 0x0)
296 || ((max & 0x00f0) != 0xf0 && (max & 0x00f0) != 0x0))
297 return -ENODEV;
298
299 /* unused bits */
300 if (conf & 0xe0)
301 return -ENODEV;
302
303 /* 0x06 and 0x07 return the last read value */
304 cur = i2c_smbus_read_word_data(client, 0);
305 if (i2c_smbus_read_word_data(client, 6) != cur
306 || i2c_smbus_read_word_data(client, 7) != cur)
307 return -ENODEV;
308 hyst = i2c_smbus_read_word_data(client, 2);
309 if (i2c_smbus_read_word_data(client, 6) != hyst
310 || i2c_smbus_read_word_data(client, 7) != hyst)
311 return -ENODEV;
312 min = i2c_smbus_read_word_data(client, 4);
313 if (i2c_smbus_read_word_data(client, 6) != min
314 || i2c_smbus_read_word_data(client, 7) != min)
315 return -ENODEV;
316
317 strlcpy(info->type, "lm77", I2C_NAME_SIZE);
318
319 return 0;
320}
321
322static void lm77_init_client(struct i2c_client *client)
323{
324 /* Initialize the LM77 chip - turn off shutdown mode */
325 int conf = lm77_read_value(client, LM77_REG_CONF);
326 if (conf & 1)
327 lm77_write_value(client, LM77_REG_CONF, conf & 0xfe);
328}
329
330static int lm77_probe(struct i2c_client *client, const struct i2c_device_id *id)
331{
332 struct device *dev = &client->dev;
333 struct device *hwmon_dev;
334 struct lm77_data *data;
335
336 data = devm_kzalloc(dev, sizeof(struct lm77_data), GFP_KERNEL);
337 if (!data)
338 return -ENOMEM;
339
340 data->client = client;
341 mutex_init(&data->update_lock);
342
343 /* Initialize the LM77 chip */
344 lm77_init_client(client);
345
346 hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
347 data, lm77_groups);
348 return PTR_ERR_OR_ZERO(hwmon_dev);
349}
350
351static const struct i2c_device_id lm77_id[] = {
352 { "lm77", 0 },
353 { }
354};
355MODULE_DEVICE_TABLE(i2c, lm77_id);
356
357/* This is the driver that will be inserted */
358static struct i2c_driver lm77_driver = {
359 .class = I2C_CLASS_HWMON,
360 .driver = {
361 .name = "lm77",
362 },
363 .probe = lm77_probe,
364 .id_table = lm77_id,
365 .detect = lm77_detect,
366 .address_list = normal_i2c,
367};
368
369module_i2c_driver(lm77_driver);
370
371MODULE_AUTHOR("Andras BALI <drewie@freemail.hu>");
372MODULE_DESCRIPTION("LM77 driver");
373MODULE_LICENSE("GPL");
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");