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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 <jdelvare@suse.de>
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
39#include <linux/module.h>
40#include <linux/init.h>
41#include <linux/slab.h>
42#include <linux/i2c.h>
43#include <linux/hwmon.h>
44#include <linux/hwmon-sysfs.h>
45#include <linux/err.h>
46#include <linux/mutex.h>
47#include <linux/jiffies.h>
48
49/*
50 * The LM92 and MAX6635 have 2 two-state pins for address selection,
51 * resulting in 4 possible addresses.
52 */
53static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
54 I2C_CLIENT_END };
55
56/* The LM92 registers */
57#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
58#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
59#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
60#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
61#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
62#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
63#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
64
65/*
66 * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
67 * left-justified in 16-bit registers. No rounding is done, with such
68 * a resolution it's just not worth it. Note that the MAX6635 doesn't
69 * make use of the 4 lower bits for limits (i.e. effective resolution
70 * for limits is 1 degree Celsius).
71 */
72static inline int TEMP_FROM_REG(s16 reg)
73{
74 return reg / 8 * 625 / 10;
75}
76
77static inline s16 TEMP_TO_REG(long val)
78{
79 val = clamp_val(val, -60000, 160000);
80 return val * 10 / 625 * 8;
81}
82
83/* Alarm flags are stored in the 3 LSB of the temperature register */
84static inline u8 ALARMS_FROM_REG(s16 reg)
85{
86 return reg & 0x0007;
87}
88
89enum temp_index {
90 t_input,
91 t_crit,
92 t_min,
93 t_max,
94 t_hyst,
95 t_num_regs
96};
97
98static const u8 regs[t_num_regs] = {
99 [t_input] = LM92_REG_TEMP,
100 [t_crit] = LM92_REG_TEMP_CRIT,
101 [t_min] = LM92_REG_TEMP_LOW,
102 [t_max] = LM92_REG_TEMP_HIGH,
103 [t_hyst] = LM92_REG_TEMP_HYST,
104};
105
106/* Client data (each client gets its own) */
107struct lm92_data {
108 struct i2c_client *client;
109 struct mutex update_lock;
110 char valid; /* zero until following fields are valid */
111 unsigned long last_updated; /* in jiffies */
112
113 /* registers values */
114 s16 temp[t_num_regs]; /* index with enum temp_index */
115};
116
117/*
118 * Sysfs attributes and callback functions
119 */
120
121static struct lm92_data *lm92_update_device(struct device *dev)
122{
123 struct lm92_data *data = dev_get_drvdata(dev);
124 struct i2c_client *client = data->client;
125 int i;
126
127 mutex_lock(&data->update_lock);
128
129 if (time_after(jiffies, data->last_updated + HZ)
130 || !data->valid) {
131 dev_dbg(&client->dev, "Updating lm92 data\n");
132 for (i = 0; i < t_num_regs; i++) {
133 data->temp[i] =
134 i2c_smbus_read_word_swapped(client, regs[i]);
135 }
136 data->last_updated = jiffies;
137 data->valid = 1;
138 }
139
140 mutex_unlock(&data->update_lock);
141
142 return data;
143}
144
145static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
146 char *buf)
147{
148 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
149 struct lm92_data *data = lm92_update_device(dev);
150
151 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
152}
153
154static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
155 const char *buf, size_t count)
156{
157 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
158 struct lm92_data *data = dev_get_drvdata(dev);
159 struct i2c_client *client = data->client;
160 int nr = attr->index;
161 long val;
162 int err;
163
164 err = kstrtol(buf, 10, &val);
165 if (err)
166 return err;
167
168 mutex_lock(&data->update_lock);
169 data->temp[nr] = TEMP_TO_REG(val);
170 i2c_smbus_write_word_swapped(client, regs[nr], data->temp[nr]);
171 mutex_unlock(&data->update_lock);
172 return count;
173}
174
175static ssize_t show_temp_hyst(struct device *dev,
176 struct device_attribute *devattr, char *buf)
177{
178 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
179 struct lm92_data *data = lm92_update_device(dev);
180 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index])
181 - TEMP_FROM_REG(data->temp[t_hyst]));
182}
183
184static ssize_t show_temp_min_hyst(struct device *dev,
185 struct device_attribute *attr, char *buf)
186{
187 struct lm92_data *data = lm92_update_device(dev);
188 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[t_min])
189 + TEMP_FROM_REG(data->temp[t_hyst]));
190}
191
192static ssize_t set_temp_hyst(struct device *dev,
193 struct device_attribute *devattr,
194 const char *buf, size_t count)
195{
196 struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
197 struct lm92_data *data = dev_get_drvdata(dev);
198 struct i2c_client *client = data->client;
199 long val;
200 int err;
201
202 err = kstrtol(buf, 10, &val);
203 if (err)
204 return err;
205
206 val = clamp_val(val, -120000, 220000);
207 mutex_lock(&data->update_lock);
208 data->temp[t_hyst] =
209 TEMP_TO_REG(TEMP_FROM_REG(data->temp[attr->index]) - val);
210 i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST,
211 data->temp[t_hyst]);
212 mutex_unlock(&data->update_lock);
213 return count;
214}
215
216static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
217 char *buf)
218{
219 struct lm92_data *data = lm92_update_device(dev);
220 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp[t_input]));
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 lm92_data *data = lm92_update_device(dev);
228 return sprintf(buf, "%d\n", (data->temp[t_input] >> bitnr) & 1);
229}
230
231static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, t_input);
232static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp, set_temp,
233 t_crit);
234static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp_hyst,
235 set_temp_hyst, t_crit);
236static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp, set_temp,
237 t_min);
238static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp_min_hyst, NULL);
239static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp, set_temp,
240 t_max);
241static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp_hyst, NULL, t_max);
242static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
243static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
244static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
245static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
246
247/*
248 * Detection and registration
249 */
250
251static void lm92_init_client(struct i2c_client *client)
252{
253 u8 config;
254
255 /* Start the conversions if needed */
256 config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
257 if (config & 0x01)
258 i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
259 config & 0xFE);
260}
261
262/*
263 * The MAX6635 has no identification register, so we have to use tricks
264 * to identify it reliably. This is somewhat slow.
265 * Note that we do NOT rely on the 2 MSB of the configuration register
266 * always reading 0, as suggested by the datasheet, because it was once
267 * reported not to be true.
268 */
269static int max6635_check(struct i2c_client *client)
270{
271 u16 temp_low, temp_high, temp_hyst, temp_crit;
272 u8 conf;
273 int i;
274
275 /*
276 * No manufacturer ID register, so a read from this address will
277 * always return the last read value.
278 */
279 temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
280 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
281 return 0;
282 temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
283 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
284 return 0;
285
286 /* Limits are stored as integer values (signed, 9-bit). */
287 if ((temp_low & 0x7f00) || (temp_high & 0x7f00))
288 return 0;
289 temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
290 temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
291 if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00))
292 return 0;
293
294 /*
295 * Registers addresses were found to cycle over 16-byte boundaries.
296 * We don't test all registers with all offsets so as to save some
297 * reads and time, but this should still be sufficient to dismiss
298 * non-MAX6635 chips.
299 */
300 conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
301 for (i = 16; i < 96; i *= 2) {
302 if (temp_hyst != i2c_smbus_read_word_data(client,
303 LM92_REG_TEMP_HYST + i - 16)
304 || temp_crit != i2c_smbus_read_word_data(client,
305 LM92_REG_TEMP_CRIT + i)
306 || temp_low != i2c_smbus_read_word_data(client,
307 LM92_REG_TEMP_LOW + i + 16)
308 || temp_high != i2c_smbus_read_word_data(client,
309 LM92_REG_TEMP_HIGH + i + 32)
310 || conf != i2c_smbus_read_byte_data(client,
311 LM92_REG_CONFIG + i))
312 return 0;
313 }
314
315 return 1;
316}
317
318static struct attribute *lm92_attrs[] = {
319 &sensor_dev_attr_temp1_input.dev_attr.attr,
320 &sensor_dev_attr_temp1_crit.dev_attr.attr,
321 &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
322 &sensor_dev_attr_temp1_min.dev_attr.attr,
323 &dev_attr_temp1_min_hyst.attr,
324 &sensor_dev_attr_temp1_max.dev_attr.attr,
325 &sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
326 &dev_attr_alarms.attr,
327 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
328 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
329 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
330 NULL
331};
332ATTRIBUTE_GROUPS(lm92);
333
334/* Return 0 if detection is successful, -ENODEV otherwise */
335static int lm92_detect(struct i2c_client *new_client,
336 struct i2c_board_info *info)
337{
338 struct i2c_adapter *adapter = new_client->adapter;
339 u8 config;
340 u16 man_id;
341
342 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
343 | I2C_FUNC_SMBUS_WORD_DATA))
344 return -ENODEV;
345
346 config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
347 man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
348
349 if ((config & 0xe0) == 0x00 && man_id == 0x0180)
350 pr_info("lm92: Found National Semiconductor LM92 chip\n");
351 else if (max6635_check(new_client))
352 pr_info("lm92: Found Maxim MAX6635 chip\n");
353 else
354 return -ENODEV;
355
356 strlcpy(info->type, "lm92", I2C_NAME_SIZE);
357
358 return 0;
359}
360
361static int lm92_probe(struct i2c_client *new_client,
362 const struct i2c_device_id *id)
363{
364 struct device *hwmon_dev;
365 struct lm92_data *data;
366
367 data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data),
368 GFP_KERNEL);
369 if (!data)
370 return -ENOMEM;
371
372 data->client = new_client;
373 mutex_init(&data->update_lock);
374
375 /* Initialize the chipset */
376 lm92_init_client(new_client);
377
378 hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
379 new_client->name,
380 data, lm92_groups);
381 return PTR_ERR_OR_ZERO(hwmon_dev);
382}
383
384
385/*
386 * Module and driver stuff
387 */
388
389static const struct i2c_device_id lm92_id[] = {
390 { "lm92", 0 },
391 /* max6635 could be added here */
392 { }
393};
394MODULE_DEVICE_TABLE(i2c, lm92_id);
395
396static struct i2c_driver lm92_driver = {
397 .class = I2C_CLASS_HWMON,
398 .driver = {
399 .name = "lm92",
400 },
401 .probe = lm92_probe,
402 .id_table = lm92_id,
403 .detect = lm92_detect,
404 .address_list = normal_i2c,
405};
406
407module_i2c_driver(lm92_driver);
408
409MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
410MODULE_DESCRIPTION("LM92/MAX6635 driver");
411MODULE_LICENSE("GPL");