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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 char valid; /* zero 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 = 1;
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 strlcpy(info->type, "lm92", I2C_NAME_SIZE);
291
292 return 0;
293}
294
295static int lm92_probe(struct i2c_client *new_client,
296 const struct i2c_device_id *id)
297{
298 struct device *hwmon_dev;
299 struct lm92_data *data;
300
301 data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data),
302 GFP_KERNEL);
303 if (!data)
304 return -ENOMEM;
305
306 data->client = new_client;
307 mutex_init(&data->update_lock);
308
309 /* Initialize the chipset */
310 lm92_init_client(new_client);
311
312 hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
313 new_client->name,
314 data, lm92_groups);
315 return PTR_ERR_OR_ZERO(hwmon_dev);
316}
317
318/*
319 * Module and driver stuff
320 */
321
322static const struct i2c_device_id lm92_id[] = {
323 { "lm92", lm92 },
324 { "max6635", max6635 },
325 { }
326};
327MODULE_DEVICE_TABLE(i2c, lm92_id);
328
329static struct i2c_driver lm92_driver = {
330 .class = I2C_CLASS_HWMON,
331 .driver = {
332 .name = "lm92",
333 },
334 .probe = lm92_probe,
335 .id_table = lm92_id,
336 .detect = lm92_detect,
337 .address_list = normal_i2c,
338};
339
340module_i2c_driver(lm92_driver);
341
342MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
343MODULE_DESCRIPTION("LM92/MAX6635 driver");
344MODULE_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 * 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#include <linux/jiffies.h>
52
53/*
54 * The LM92 and MAX6635 have 2 two-state pins for address selection,
55 * resulting in 4 possible addresses.
56 */
57static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
58 I2C_CLIENT_END };
59
60/* The LM92 registers */
61#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
62#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
63#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
64#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
65#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
66#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
67#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
68
69/*
70 * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
71 * left-justified in 16-bit registers. No rounding is done, with such
72 * a resolution it's just not worth it. Note that the MAX6635 doesn't
73 * make use of the 4 lower bits for limits (i.e. effective resolution
74 * for limits is 1 degree Celsius).
75 */
76static inline int TEMP_FROM_REG(s16 reg)
77{
78 return reg / 8 * 625 / 10;
79}
80
81static inline s16 TEMP_TO_REG(int val)
82{
83 if (val <= -60000)
84 return -60000 * 10 / 625 * 8;
85 if (val >= 160000)
86 return 160000 * 10 / 625 * 8;
87 return val * 10 / 625 * 8;
88}
89
90/* Alarm flags are stored in the 3 LSB of the temperature register */
91static inline u8 ALARMS_FROM_REG(s16 reg)
92{
93 return reg & 0x0007;
94}
95
96/* Driver data (common to all clients) */
97static struct i2c_driver lm92_driver;
98
99/* Client data (each client gets its own) */
100struct lm92_data {
101 struct device *hwmon_dev;
102 struct mutex update_lock;
103 char valid; /* zero until following fields are valid */
104 unsigned long last_updated; /* in jiffies */
105
106 /* registers values */
107 s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
108};
109
110
111/*
112 * Sysfs attributes and callback functions
113 */
114
115static struct lm92_data *lm92_update_device(struct device *dev)
116{
117 struct i2c_client *client = to_i2c_client(dev);
118 struct lm92_data *data = i2c_get_clientdata(client);
119
120 mutex_lock(&data->update_lock);
121
122 if (time_after(jiffies, data->last_updated + HZ)
123 || !data->valid) {
124 dev_dbg(&client->dev, "Updating lm92 data\n");
125 data->temp1_input = i2c_smbus_read_word_swapped(client,
126 LM92_REG_TEMP);
127 data->temp1_hyst = i2c_smbus_read_word_swapped(client,
128 LM92_REG_TEMP_HYST);
129 data->temp1_crit = i2c_smbus_read_word_swapped(client,
130 LM92_REG_TEMP_CRIT);
131 data->temp1_min = i2c_smbus_read_word_swapped(client,
132 LM92_REG_TEMP_LOW);
133 data->temp1_max = i2c_smbus_read_word_swapped(client,
134 LM92_REG_TEMP_HIGH);
135
136 data->last_updated = jiffies;
137 data->valid = 1;
138 }
139
140 mutex_unlock(&data->update_lock);
141
142 return data;
143}
144
145#define show_temp(value) \
146static ssize_t show_##value(struct device *dev, struct device_attribute *attr, \
147 char *buf) \
148{ \
149 struct lm92_data *data = lm92_update_device(dev); \
150 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
151}
152show_temp(temp1_input);
153show_temp(temp1_crit);
154show_temp(temp1_min);
155show_temp(temp1_max);
156
157#define set_temp(value, reg) \
158static ssize_t set_##value(struct device *dev, struct device_attribute *attr, \
159 const char *buf, \
160 size_t count) \
161{ \
162 struct i2c_client *client = to_i2c_client(dev); \
163 struct lm92_data *data = i2c_get_clientdata(client); \
164 long val; \
165 int err = kstrtol(buf, 10, &val); \
166 if (err) \
167 return err; \
168\
169 mutex_lock(&data->update_lock); \
170 data->value = TEMP_TO_REG(val); \
171 i2c_smbus_write_word_swapped(client, reg, data->value); \
172 mutex_unlock(&data->update_lock); \
173 return count; \
174}
175set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
176set_temp(temp1_min, LM92_REG_TEMP_LOW);
177set_temp(temp1_max, LM92_REG_TEMP_HIGH);
178
179static ssize_t show_temp1_crit_hyst(struct device *dev,
180 struct device_attribute *attr, char *buf)
181{
182 struct lm92_data *data = lm92_update_device(dev);
183 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
184 - TEMP_FROM_REG(data->temp1_hyst));
185}
186static ssize_t show_temp1_max_hyst(struct device *dev,
187 struct device_attribute *attr, char *buf)
188{
189 struct lm92_data *data = lm92_update_device(dev);
190 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
191 - TEMP_FROM_REG(data->temp1_hyst));
192}
193static ssize_t show_temp1_min_hyst(struct device *dev,
194 struct device_attribute *attr, char *buf)
195{
196 struct lm92_data *data = lm92_update_device(dev);
197 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
198 + TEMP_FROM_REG(data->temp1_hyst));
199}
200
201static ssize_t set_temp1_crit_hyst(struct device *dev,
202 struct device_attribute *attr,
203 const char *buf, size_t count)
204{
205 struct i2c_client *client = to_i2c_client(dev);
206 struct lm92_data *data = i2c_get_clientdata(client);
207 long val;
208 int err;
209
210 err = kstrtol(buf, 10, &val);
211 if (err)
212 return err;
213
214 mutex_lock(&data->update_lock);
215 data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
216 i2c_smbus_write_word_swapped(client, LM92_REG_TEMP_HYST,
217 TEMP_TO_REG(data->temp1_hyst));
218 mutex_unlock(&data->update_lock);
219 return count;
220}
221
222static ssize_t show_alarms(struct device *dev, struct device_attribute *attr,
223 char *buf)
224{
225 struct lm92_data *data = lm92_update_device(dev);
226 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
227}
228
229static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
230 char *buf)
231{
232 int bitnr = to_sensor_dev_attr(attr)->index;
233 struct lm92_data *data = lm92_update_device(dev);
234 return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1);
235}
236
237static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
238static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit,
239 set_temp1_crit);
240static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst,
241 set_temp1_crit_hyst);
242static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min,
243 set_temp1_min);
244static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
245static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max,
246 set_temp1_max);
247static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
248static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
249static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
250static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
251static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
252
253
254/*
255 * Detection and registration
256 */
257
258static void lm92_init_client(struct i2c_client *client)
259{
260 u8 config;
261
262 /* Start the conversions if needed */
263 config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
264 if (config & 0x01)
265 i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
266 config & 0xFE);
267}
268
269/*
270 * The MAX6635 has no identification register, so we have to use tricks
271 * to identify it reliably. This is somewhat slow.
272 * Note that we do NOT rely on the 2 MSB of the configuration register
273 * always reading 0, as suggested by the datasheet, because it was once
274 * reported not to be true.
275 */
276static int max6635_check(struct i2c_client *client)
277{
278 u16 temp_low, temp_high, temp_hyst, temp_crit;
279 u8 conf;
280 int i;
281
282 /*
283 * No manufacturer ID register, so a read from this address will
284 * always return the last read value.
285 */
286 temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
287 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
288 return 0;
289 temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
290 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
291 return 0;
292
293 /* Limits are stored as integer values (signed, 9-bit). */
294 if ((temp_low & 0x7f00) || (temp_high & 0x7f00))
295 return 0;
296 temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
297 temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
298 if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00))
299 return 0;
300
301 /*
302 * Registers addresses were found to cycle over 16-byte boundaries.
303 * We don't test all registers with all offsets so as to save some
304 * reads and time, but this should still be sufficient to dismiss
305 * non-MAX6635 chips.
306 */
307 conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
308 for (i = 16; i < 96; i *= 2) {
309 if (temp_hyst != i2c_smbus_read_word_data(client,
310 LM92_REG_TEMP_HYST + i - 16)
311 || temp_crit != i2c_smbus_read_word_data(client,
312 LM92_REG_TEMP_CRIT + i)
313 || temp_low != i2c_smbus_read_word_data(client,
314 LM92_REG_TEMP_LOW + i + 16)
315 || temp_high != i2c_smbus_read_word_data(client,
316 LM92_REG_TEMP_HIGH + i + 32)
317 || conf != i2c_smbus_read_byte_data(client,
318 LM92_REG_CONFIG + i))
319 return 0;
320 }
321
322 return 1;
323}
324
325static struct attribute *lm92_attributes[] = {
326 &dev_attr_temp1_input.attr,
327 &dev_attr_temp1_crit.attr,
328 &dev_attr_temp1_crit_hyst.attr,
329 &dev_attr_temp1_min.attr,
330 &dev_attr_temp1_min_hyst.attr,
331 &dev_attr_temp1_max.attr,
332 &dev_attr_temp1_max_hyst.attr,
333 &dev_attr_alarms.attr,
334 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
335 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
336 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
337 NULL
338};
339
340static const struct attribute_group lm92_group = {
341 .attrs = lm92_attributes,
342};
343
344/* Return 0 if detection is successful, -ENODEV otherwise */
345static int lm92_detect(struct i2c_client *new_client,
346 struct i2c_board_info *info)
347{
348 struct i2c_adapter *adapter = new_client->adapter;
349 u8 config;
350 u16 man_id;
351
352 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
353 | I2C_FUNC_SMBUS_WORD_DATA))
354 return -ENODEV;
355
356 config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
357 man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
358
359 if ((config & 0xe0) == 0x00 && man_id == 0x0180)
360 pr_info("lm92: Found National Semiconductor LM92 chip\n");
361 else if (max6635_check(new_client))
362 pr_info("lm92: Found Maxim MAX6635 chip\n");
363 else
364 return -ENODEV;
365
366 strlcpy(info->type, "lm92", I2C_NAME_SIZE);
367
368 return 0;
369}
370
371static int lm92_probe(struct i2c_client *new_client,
372 const struct i2c_device_id *id)
373{
374 struct lm92_data *data;
375 int err;
376
377 data = devm_kzalloc(&new_client->dev, sizeof(struct lm92_data),
378 GFP_KERNEL);
379 if (!data)
380 return -ENOMEM;
381
382 i2c_set_clientdata(new_client, data);
383 mutex_init(&data->update_lock);
384
385 /* Initialize the chipset */
386 lm92_init_client(new_client);
387
388 /* Register sysfs hooks */
389 err = sysfs_create_group(&new_client->dev.kobj, &lm92_group);
390 if (err)
391 return err;
392
393 data->hwmon_dev = hwmon_device_register(&new_client->dev);
394 if (IS_ERR(data->hwmon_dev)) {
395 err = PTR_ERR(data->hwmon_dev);
396 goto exit_remove;
397 }
398
399 return 0;
400
401exit_remove:
402 sysfs_remove_group(&new_client->dev.kobj, &lm92_group);
403 return err;
404}
405
406static int lm92_remove(struct i2c_client *client)
407{
408 struct lm92_data *data = i2c_get_clientdata(client);
409
410 hwmon_device_unregister(data->hwmon_dev);
411 sysfs_remove_group(&client->dev.kobj, &lm92_group);
412
413 return 0;
414}
415
416
417/*
418 * Module and driver stuff
419 */
420
421static const struct i2c_device_id lm92_id[] = {
422 { "lm92", 0 },
423 /* max6635 could be added here */
424 { }
425};
426MODULE_DEVICE_TABLE(i2c, lm92_id);
427
428static struct i2c_driver lm92_driver = {
429 .class = I2C_CLASS_HWMON,
430 .driver = {
431 .name = "lm92",
432 },
433 .probe = lm92_probe,
434 .remove = lm92_remove,
435 .id_table = lm92_id,
436 .detect = lm92_detect,
437 .address_list = normal_i2c,
438};
439
440module_i2c_driver(lm92_driver);
441
442MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
443MODULE_DESCRIPTION("LM92/MAX6635 driver");
444MODULE_LICENSE("GPL");