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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * lm92 - Hardware monitoring driver
4 * Copyright (C) 2005-2008 Jean Delvare <jdelvare@suse.de>
5 *
6 * Based on the lm90 driver, with some ideas taken from the lm_sensors
7 * lm92 driver as well.
8 *
9 * The LM92 is a sensor chip made by National Semiconductor. It reports
10 * its own temperature with a 0.0625 deg resolution and a 0.33 deg
11 * accuracy. Complete datasheet can be obtained from National's website
12 * at:
13 * http://www.national.com/pf/LM/LM92.html
14 *
15 * This driver also supports the MAX6635 sensor chip made by Maxim.
16 * This chip is compatible with the LM92, but has a lesser accuracy
17 * (1.0 deg). Complete datasheet can be obtained from Maxim's website
18 * at:
19 * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074
20 *
21 * Since the LM92 was the first chipset supported by this driver, most
22 * comments will refer to this chipset, but are actually general and
23 * concern all supported chipsets, unless mentioned otherwise.
24 *
25 * Support could easily be added for the National Semiconductor LM76
26 * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible
27 * with the LM92.
28 */
29
30#include <linux/module.h>
31#include <linux/init.h>
32#include <linux/slab.h>
33#include <linux/i2c.h>
34#include <linux/hwmon.h>
35#include <linux/hwmon-sysfs.h>
36#include <linux/err.h>
37#include <linux/mutex.h>
38#include <linux/jiffies.h>
39
40/*
41 * The LM92 and MAX6635 have 2 two-state pins for address selection,
42 * resulting in 4 possible addresses.
43 */
44static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
45 I2C_CLIENT_END };
46enum chips { lm92, max6635 };
47
48/* The LM92 registers */
49#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
50#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
51#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
52#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
53#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
54#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
55#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
56
57/*
58 * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
59 * left-justified in 16-bit registers. No rounding is done, with such
60 * a resolution it's just not worth it. Note that the MAX6635 doesn't
61 * make use of the 4 lower bits for limits (i.e. effective resolution
62 * for limits is 1 degree Celsius).
63 */
64static inline int TEMP_FROM_REG(s16 reg)
65{
66 return reg / 8 * 625 / 10;
67}
68
69static inline s16 TEMP_TO_REG(long val)
70{
71 val = clamp_val(val, -60000, 160000);
72 return val * 10 / 625 * 8;
73}
74
75/* Alarm flags are stored in the 3 LSB of the temperature register */
76static inline u8 ALARMS_FROM_REG(s16 reg)
77{
78 return reg & 0x0007;
79}
80
81enum temp_index {
82 t_input,
83 t_crit,
84 t_min,
85 t_max,
86 t_hyst,
87 t_num_regs
88};
89
90static const u8 regs[t_num_regs] = {
91 [t_input] = LM92_REG_TEMP,
92 [t_crit] = LM92_REG_TEMP_CRIT,
93 [t_min] = LM92_REG_TEMP_LOW,
94 [t_max] = LM92_REG_TEMP_HIGH,
95 [t_hyst] = LM92_REG_TEMP_HYST,
96};
97
98/* Client data (each client gets its own) */
99struct lm92_data {
100 struct i2c_client *client;
101 struct mutex update_lock;
102 bool valid; /* false until following fields are valid */
103 unsigned long last_updated; /* in jiffies */
104
105 /* registers values */
106 s16 temp[t_num_regs]; /* index with enum temp_index */
107};
108
109/*
110 * Sysfs attributes and callback functions
111 */
112
113static struct lm92_data *lm92_update_device(struct device *dev)
114{
115 struct lm92_data *data = dev_get_drvdata(dev);
116 struct i2c_client *client = data->client;
117 int i;
118
119 mutex_lock(&data->update_lock);
120
121 if (time_after(jiffies, data->last_updated + HZ) ||
122 !data->valid) {
123 dev_dbg(&client->dev, "Updating lm92 data\n");
124 for (i = 0; i < t_num_regs; i++) {
125 data->temp[i] =
126 i2c_smbus_read_word_swapped(client, regs[i]);
127 }
128 data->last_updated = jiffies;
129 data->valid = true;
130 }
131
132 mutex_unlock(&data->update_lock);
133
134 return data;
135}
136
137static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
138 char *buf)
139{
140 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
141 struct lm92_data *data = lm92_update_device(dev);
142
143 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
144}
145
146static ssize_t temp_store(struct device *dev,
147 struct device_attribute *devattr, const char *buf,
148 size_t count)
149{
150 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
151 struct lm92_data *data = dev_get_drvdata(dev);
152 struct i2c_client *client = data->client;
153 int nr = attr->index;
154 long val;
155 int err;
156
157 err = kstrtol(buf, 10, &val);
158 if (err)
159 return err;
160
161 mutex_lock(&data->update_lock);
162 data->temp[nr] = TEMP_TO_REG(val);
163 i2c_smbus_write_word_swapped(client, regs[nr], data->temp[nr]);
164 mutex_unlock(&data->update_lock);
165 return count;
166}
167
168static ssize_t temp_hyst_show(struct device *dev,
169 struct device_attribute *devattr, char *buf)
170{
171 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
172 struct lm92_data *data = lm92_update_device(dev);
173
174 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])
175 - TEMP_FROM_REG(data->temp[t_hyst]));
176}
177
178static ssize_t temp1_min_hyst_show(struct device *dev,
179 struct device_attribute *attr, char *buf)
180{
181 struct lm92_data *data = lm92_update_device(dev);
182
183 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[t_min])
184 + TEMP_FROM_REG(data->temp[t_hyst]));
185}
186
187static ssize_t temp_hyst_store(struct device *dev,
188 struct device_attribute *devattr,
189 const char *buf, size_t count)
190{
191 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
192 struct lm92_data *data = dev_get_drvdata(dev);
193 struct i2c_client *client = data->client;
194 long val;
195 int err;
196
197 err = kstrtol(buf, 10, &val);
198 if (err)
199 return err;
200
201 val = clamp_val(val, -120000, 220000);
202 mutex_lock(&data->update_lock);
203 data->temp[t_hyst] =
204 TEMP_TO_REG(TEMP_FROM_REG(data->temp[attr->index]) - val);
205 i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST,
206 data->temp[t_hyst]);
207 mutex_unlock(&data->update_lock);
208 return count;
209}
210
211static ssize_t alarms_show(struct device *dev, struct device_attribute *attr,
212 char *buf)
213{
214 struct lm92_data *data = lm92_update_device(dev);
215
216 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp[t_input]));
217}
218
219static ssize_t alarm_show(struct device *dev, struct device_attribute *attr,
220 char *buf)
221{
222 int bitnr = to_sensor_dev_attr(attr)->index;
223 struct lm92_data *data = lm92_update_device(dev);
224 return sprintf(buf, "%d\n", (data->temp[t_input] >> bitnr) & 1);
225}
226
227static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, t_input);
228static SENSOR_DEVICE_ATTR_RW(temp1_crit, temp, t_crit);
229static SENSOR_DEVICE_ATTR_RW(temp1_crit_hyst, temp_hyst, t_crit);
230static SENSOR_DEVICE_ATTR_RW(temp1_min, temp, t_min);
231static DEVICE_ATTR_RO(temp1_min_hyst);
232static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, t_max);
233static SENSOR_DEVICE_ATTR_RO(temp1_max_hyst, temp_hyst, t_max);
234static DEVICE_ATTR_RO(alarms);
235static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 2);
236static SENSOR_DEVICE_ATTR_RO(temp1_min_alarm, alarm, 0);
237static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 1);
238
239/*
240 * Detection and registration
241 */
242
243static void lm92_init_client(struct i2c_client *client)
244{
245 u8 config;
246
247 /* Start the conversions if needed */
248 config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
249 if (config & 0x01)
250 i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
251 config & 0xFE);
252}
253
254static struct attribute *lm92_attrs[] = {
255 &sensor_dev_attr_temp1_input.dev_attr.attr,
256 &sensor_dev_attr_temp1_crit.dev_attr.attr,
257 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
258 &sensor_dev_attr_temp1_min.dev_attr.attr,
259 &dev_attr_temp1_min_hyst.attr,
260 &sensor_dev_attr_temp1_max.dev_attr.attr,
261 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
262 &dev_attr_alarms.attr,
263 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
264 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
265 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
266 NULL
267};
268ATTRIBUTE_GROUPS(lm92);
269
270/* Return 0 if detection is successful, -ENODEV otherwise */
271static int lm92_detect(struct i2c_client *new_client,
272 struct i2c_board_info *info)
273{
274 struct i2c_adapter *adapter = new_client->adapter;
275 u8 config;
276 u16 man_id;
277
278 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
279 | I2C_FUNC_SMBUS_WORD_DATA))
280 return -ENODEV;
281
282 config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
283 man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
284
285 if ((config & 0xe0) == 0x00 && man_id == 0x0180)
286 pr_info("lm92: Found National Semiconductor LM92 chip\n");
287 else
288 return -ENODEV;
289
290 strscpy(info->type, "lm92", I2C_NAME_SIZE);
291
292 return 0;
293}
294
295static int lm92_probe(struct i2c_client *new_client)
296{
297 struct device *hwmon_dev;
298 struct lm92_data *data;
299
300 data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data),
301 GFP_KERNEL);
302 if (!data)
303 return -ENOMEM;
304
305 data->client = new_client;
306 mutex_init(&data->update_lock);
307
308 /* Initialize the chipset */
309 lm92_init_client(new_client);
310
311 hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
312 new_client->name,
313 data, lm92_groups);
314 return PTR_ERR_OR_ZERO(hwmon_dev);
315}
316
317/*
318 * Module and driver stuff
319 */
320
321static const struct i2c_device_id lm92_id[] = {
322 { "lm92", lm92 },
323 { "max6635", max6635 },
324 { }
325};
326MODULE_DEVICE_TABLE(i2c, lm92_id);
327
328static struct i2c_driver lm92_driver = {
329 .class = I2C_CLASS_HWMON,
330 .driver = {
331 .name = "lm92",
332 },
333 .probe = lm92_probe,
334 .id_table = lm92_id,
335 .detect = lm92_detect,
336 .address_list = normal_i2c,
337};
338
339module_i2c_driver(lm92_driver);
340
341MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
342MODULE_DESCRIPTION("LM92/MAX6635 driver");
343MODULE_LICENSE("GPL");
1/*
2 * lm92 - Hardware monitoring driver
3 * Copyright (C) 2005-2008 Jean Delvare <khali@linux-fr.org>
4 *
5 * Based on the lm90 driver, with some ideas taken from the lm_sensors
6 * lm92 driver as well.
7 *
8 * The LM92 is a sensor chip made by National Semiconductor. It reports
9 * its own temperature with a 0.0625 deg resolution and a 0.33 deg
10 * accuracy. Complete datasheet can be obtained from National's website
11 * at:
12 * http://www.national.com/pf/LM/LM92.html
13 *
14 * This driver also supports the MAX6635 sensor chip made by Maxim.
15 * This chip is compatible with the LM92, but has a lesser accuracy
16 * (1.0 deg). Complete datasheet can be obtained from Maxim's website
17 * at:
18 * http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3074
19 *
20 * Since the LM92 was the first chipset supported by this driver, most
21 * comments will refer to this chipset, but are actually general and
22 * concern all supported chipsets, unless mentioned otherwise.
23 *
24 * Support could easily be added for the National Semiconductor LM76
25 * and Maxim MAX6633 and MAX6634 chips, which are mostly compatible
26 * with the LM92.
27 *
28 * This program is free software; you can redistribute it and/or modify
29 * it under the terms of the GNU General Public License as published by
30 * the Free Software Foundation; either version 2 of the License, or
31 * (at your option) any later version.
32 *
33 * This program is distributed in the hope that it will be useful,
34 * but WITHOUT ANY WARRANTY; without even the implied warranty of
35 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
36 * GNU General Public License for more details.
37 *
38 * You should have received a copy of the GNU General Public License
39 * along with this program; if not, write to the Free Software
40 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
41 */
42
43#include <linux/module.h>
44#include <linux/init.h>
45#include <linux/slab.h>
46#include <linux/i2c.h>
47#include <linux/hwmon.h>
48#include <linux/hwmon-sysfs.h>
49#include <linux/err.h>
50#include <linux/mutex.h>
51
52/*
53 * The LM92 and MAX6635 have 2 two-state pins for address selection,
54 * resulting in 4 possible addresses.
55 */
56static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
57 I2C_CLIENT_END };
58
59/* The LM92 registers */
60#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
61#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
62#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
63#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
64#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
65#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
66#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
67
68/*
69 * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
70 * left-justified in 16-bit registers. No rounding is done, with such
71 * a resolution it's just not worth it. Note that the MAX6635 doesn't
72 * make use of the 4 lower bits for limits (i.e. effective resolution
73 * for limits is 1 degree Celsius).
74 */
75static inline int TEMP_FROM_REG(s16 reg)
76{
77 return reg / 8 * 625 / 10;
78}
79
80static inline s16 TEMP_TO_REG(int val)
81{
82 if (val <= -60000)
83 return -60000 * 10 / 625 * 8;
84 if (val >= 160000)
85 return 160000 * 10 / 625 * 8;
86 return val * 10 / 625 * 8;
87}
88
89/* Alarm flags are stored in the 3 LSB of the temperature register */
90static inline u8 ALARMS_FROM_REG(s16 reg)
91{
92 return reg & 0x0007;
93}
94
95/* Driver data (common to all clients) */
96static struct i2c_driver lm92_driver;
97
98/* Client data (each client gets its own) */
99struct lm92_data {
100 struct device *hwmon_dev;
101 struct mutex update_lock;
102 char valid; /* zero until following fields are valid */
103 unsigned long last_updated; /* in jiffies */
104
105 /* registers values */
106 s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
107};
108
109
110/*
111 * Sysfs attributes and callback functions
112 */
113
114static struct lm92_data *lm92_update_device(struct device *dev)
115{
116 struct i2c_client *client = to_i2c_client(dev);
117 struct lm92_data *data = i2c_get_clientdata(client);
118
119 mutex_lock(&data->update_lock);
120
121 if (time_after(jiffies, data->last_updated + HZ)
122 || !data->valid) {
123 dev_dbg(&client->dev, "Updating lm92 data\n");
124 data->temp1_input = i2c_smbus_read_word_swapped(client,
125 LM92_REG_TEMP);
126 data->temp1_hyst = i2c_smbus_read_word_swapped(client,
127 LM92_REG_TEMP_HYST);
128 data->temp1_crit = i2c_smbus_read_word_swapped(client,
129 LM92_REG_TEMP_CRIT);
130 data->temp1_min = i2c_smbus_read_word_swapped(client,
131 LM92_REG_TEMP_LOW);
132 data->temp1_max = i2c_smbus_read_word_swapped(client,
133 LM92_REG_TEMP_HIGH);
134
135 data->last_updated = jiffies;
136 data->valid = 1;
137 }
138
139 mutex_unlock(&data->update_lock);
140
141 return data;
142}
143
144#define show_temp(value) \
145static ssize_t show_##value(struct device *dev, struct device_attribute *attr, \
146 char *buf) \
147{ \
148 struct lm92_data *data = lm92_update_device(dev); \
149 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
150}
151show_temp(temp1_input);
152show_temp(temp1_crit);
153show_temp(temp1_min);
154show_temp(temp1_max);
155
156#define set_temp(value, reg) \
157static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
158 const char *buf, \
159 size_t count) \
160{ \
161 struct i2c_client *client = to_i2c_client(dev); \
162 struct lm92_data *data = i2c_get_clientdata(client); \
163 long val; \
164 int err = kstrtol(buf, 10, &val); \
165 if (err) \
166 return err; \
167\
168 mutex_lock(&data->update_lock); \
169 data->value = TEMP_TO_REG(val); \
170 i2c_smbus_write_word_swapped(client, reg, data->value); \
171 mutex_unlock(&data->update_lock); \
172 return count; \
173}
174set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
175set_temp(temp1_min, LM92_REG_TEMP_LOW);
176set_temp(temp1_max, LM92_REG_TEMP_HIGH);
177
178static ssize_t show_temp1_crit_hyst(struct device *dev,
179 struct device_attribute *attr, char *buf)
180{
181 struct lm92_data *data = lm92_update_device(dev);
182 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
183 - TEMP_FROM_REG(data->temp1_hyst));
184}
185static ssize_t show_temp1_max_hyst(struct device *dev,
186 struct device_attribute *attr, char *buf)
187{
188 struct lm92_data *data = lm92_update_device(dev);
189 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
190 - TEMP_FROM_REG(data->temp1_hyst));
191}
192static ssize_t show_temp1_min_hyst(struct device *dev,
193 struct device_attribute *attr, char *buf)
194{
195 struct lm92_data *data = lm92_update_device(dev);
196 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
197 + TEMP_FROM_REG(data->temp1_hyst));
198}
199
200static ssize_t set_temp1_crit_hyst(struct device *dev,
201 struct device_attribute *attr,
202 const char *buf, size_t count)
203{
204 struct i2c_client *client = to_i2c_client(dev);
205 struct lm92_data *data = i2c_get_clientdata(client);
206 long val;
207 int err;
208
209 err = kstrtol(buf, 10, &val);
210 if (err)
211 return err;
212
213 mutex_lock(&data->update_lock);
214 data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
215 i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST,
216 TEMP_TO_REG(data->temp1_hyst));
217 mutex_unlock(&data->update_lock);
218 return count;
219}
220
221static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
222 char *buf)
223{
224 struct lm92_data *data = lm92_update_device(dev);
225 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
226}
227
228static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
229 char *buf)
230{
231 int bitnr = to_sensor_dev_attr(attr)->index;
232 struct lm92_data *data = lm92_update_device(dev);
233 return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1);
234}
235
236static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
237static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit,
238 set_temp1_crit);
239static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst,
240 set_temp1_crit_hyst);
241static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min,
242 set_temp1_min);
243static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
244static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max,
245 set_temp1_max);
246static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
247static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
248static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
249static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
250static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
251
252
253/*
254 * Detection and registration
255 */
256
257static void lm92_init_client(struct i2c_client *client)
258{
259 u8 config;
260
261 /* Start the conversions if needed */
262 config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
263 if (config & 0x01)
264 i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
265 config & 0xFE);
266}
267
268/*
269 * The MAX6635 has no identification register, so we have to use tricks
270 * to identify it reliably. This is somewhat slow.
271 * Note that we do NOT rely on the 2 MSB of the configuration register
272 * always reading 0, as suggested by the datasheet, because it was once
273 * reported not to be true.
274 */
275static int max6635_check(struct i2c_client *client)
276{
277 u16 temp_low, temp_high, temp_hyst, temp_crit;
278 u8 conf;
279 int i;
280
281 /*
282 * No manufacturer ID register, so a read from this address will
283 * always return the last read value.
284 */
285 temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
286 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
287 return 0;
288 temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
289 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
290 return 0;
291
292 /* Limits are stored as integer values (signed, 9-bit). */
293 if ((temp_low & 0x7f00) || (temp_high & 0x7f00))
294 return 0;
295 temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
296 temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
297 if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00))
298 return 0;
299
300 /*
301 * Registers addresses were found to cycle over 16-byte boundaries.
302 * We don't test all registers with all offsets so as to save some
303 * reads and time, but this should still be sufficient to dismiss
304 * non-MAX6635 chips.
305 */
306 conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
307 for (i = 16; i < 96; i *= 2) {
308 if (temp_hyst != i2c_smbus_read_word_data(client,
309 LM92_REG_TEMP_HYST + i - 16)
310 || temp_crit != i2c_smbus_read_word_data(client,
311 LM92_REG_TEMP_CRIT + i)
312 || temp_low != i2c_smbus_read_word_data(client,
313 LM92_REG_TEMP_LOW + i + 16)
314 || temp_high != i2c_smbus_read_word_data(client,
315 LM92_REG_TEMP_HIGH + i + 32)
316 || conf != i2c_smbus_read_byte_data(client,
317 LM92_REG_CONFIG + i))
318 return 0;
319 }
320
321 return 1;
322}
323
324static struct attribute *lm92_attributes[] = {
325 &dev_attr_temp1_input.attr,
326 &dev_attr_temp1_crit.attr,
327 &dev_attr_temp1_crit_hyst.attr,
328 &dev_attr_temp1_min.attr,
329 &dev_attr_temp1_min_hyst.attr,
330 &dev_attr_temp1_max.attr,
331 &dev_attr_temp1_max_hyst.attr,
332 &dev_attr_alarms.attr,
333 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
334 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
335 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
336 NULL
337};
338
339static const struct attribute_group lm92_group = {
340 .attrs = lm92_attributes,
341};
342
343/* Return 0 if detection is successful, -ENODEV otherwise */
344static int lm92_detect(struct i2c_client *new_client,
345 struct i2c_board_info *info)
346{
347 struct i2c_adapter *adapter = new_client->adapter;
348 u8 config;
349 u16 man_id;
350
351 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
352 | I2C_FUNC_SMBUS_WORD_DATA))
353 return -ENODEV;
354
355 config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
356 man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
357
358 if ((config & 0xe0) == 0x00 && man_id == 0x0180)
359 pr_info("lm92: Found National Semiconductor LM92 chip\n");
360 else if (max6635_check(new_client))
361 pr_info("lm92: Found Maxim MAX6635 chip\n");
362 else
363 return -ENODEV;
364
365 strlcpy(info->type, "lm92", I2C_NAME_SIZE);
366
367 return 0;
368}
369
370static int lm92_probe(struct i2c_client *new_client,
371 const struct i2c_device_id *id)
372{
373 struct lm92_data *data;
374 int err;
375
376 data = kzalloc(sizeof(struct lm92_data), GFP_KERNEL);
377 if (!data) {
378 err = -ENOMEM;
379 goto exit;
380 }
381
382 i2c_set_clientdata(new_client, data);
383 data->valid = 0;
384 mutex_init(&data->update_lock);
385
386 /* Initialize the chipset */
387 lm92_init_client(new_client);
388
389 /* Register sysfs hooks */
390 err = sysfs_create_group(&new_client->dev.kobj, &lm92_group);
391 if (err)
392 goto exit_free;
393
394 data->hwmon_dev = hwmon_device_register(&new_client->dev);
395 if (IS_ERR(data->hwmon_dev)) {
396 err = PTR_ERR(data->hwmon_dev);
397 goto exit_remove;
398 }
399
400 return 0;
401
402exit_remove:
403 sysfs_remove_group(&new_client->dev.kobj, &lm92_group);
404exit_free:
405 kfree(data);
406exit:
407 return err;
408}
409
410static int lm92_remove(struct i2c_client *client)
411{
412 struct lm92_data *data = i2c_get_clientdata(client);
413
414 hwmon_device_unregister(data->hwmon_dev);
415 sysfs_remove_group(&client->dev.kobj, &lm92_group);
416
417 kfree(data);
418 return 0;
419}
420
421
422/*
423 * Module and driver stuff
424 */
425
426static const struct i2c_device_id lm92_id[] = {
427 { "lm92", 0 },
428 /* max6635 could be added here */
429 { }
430};
431MODULE_DEVICE_TABLE(i2c, lm92_id);
432
433static struct i2c_driver lm92_driver = {
434 .class = I2C_CLASS_HWMON,
435 .driver = {
436 .name = "lm92",
437 },
438 .probe = lm92_probe,
439 .remove = lm92_remove,
440 .id_table = lm92_id,
441 .detect = lm92_detect,
442 .address_list = normal_i2c,
443};
444
445module_i2c_driver(lm92_driver);
446
447MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
448MODULE_DESCRIPTION("LM92/MAX6635 driver");
449MODULE_LICENSE("GPL");