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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/* The LM92 and MAX6635 have 2 two-state pins for address selection,
53 resulting in 4 possible addresses. */
54static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
55 I2C_CLIENT_END };
56
57/* The LM92 registers */
58#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
59#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
60#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
61#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
62#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
63#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
64#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
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). */
71static inline int TEMP_FROM_REG(s16 reg)
72{
73 return reg / 8 * 625 / 10;
74}
75
76static inline s16 TEMP_TO_REG(int val)
77{
78 if (val <= -60000)
79 return -60000 * 10 / 625 * 8;
80 if (val >= 160000)
81 return 160000 * 10 / 625 * 8;
82 return val * 10 / 625 * 8;
83}
84
85/* Alarm flags are stored in the 3 LSB of the temperature register */
86static inline u8 ALARMS_FROM_REG(s16 reg)
87{
88 return reg & 0x0007;
89}
90
91/* Driver data (common to all clients) */
92static struct i2c_driver lm92_driver;
93
94/* Client data (each client gets its own) */
95struct lm92_data {
96 struct device *hwmon_dev;
97 struct mutex update_lock;
98 char valid; /* zero until following fields are valid */
99 unsigned long last_updated; /* in jiffies */
100
101 /* registers values */
102 s16 temp1_input, temp1_crit, temp1_min, temp1_max, temp1_hyst;
103};
104
105
106/*
107 * Sysfs attributes and callback functions
108 */
109
110static struct lm92_data *lm92_update_device(struct device *dev)
111{
112 struct i2c_client *client = to_i2c_client(dev);
113 struct lm92_data *data = i2c_get_clientdata(client);
114
115 mutex_lock(&data->update_lock);
116
117 if (time_after(jiffies, data->last_updated + HZ)
118 || !data->valid) {
119 dev_dbg(&client->dev, "Updating lm92 data\n");
120 data->temp1_input = swab16(i2c_smbus_read_word_data(client,
121 LM92_REG_TEMP));
122 data->temp1_hyst = swab16(i2c_smbus_read_word_data(client,
123 LM92_REG_TEMP_HYST));
124 data->temp1_crit = swab16(i2c_smbus_read_word_data(client,
125 LM92_REG_TEMP_CRIT));
126 data->temp1_min = swab16(i2c_smbus_read_word_data(client,
127 LM92_REG_TEMP_LOW));
128 data->temp1_max = swab16(i2c_smbus_read_word_data(client,
129 LM92_REG_TEMP_HIGH));
130
131 data->last_updated = jiffies;
132 data->valid = 1;
133 }
134
135 mutex_unlock(&data->update_lock);
136
137 return data;
138}
139
140#define show_temp(value) \
141static ssize_t show_##value(struct device *dev, struct device_attribute *attr, char *buf) \
142{ \
143 struct lm92_data *data = lm92_update_device(dev); \
144 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->value)); \
145}
146show_temp(temp1_input);
147show_temp(temp1_crit);
148show_temp(temp1_min);
149show_temp(temp1_max);
150
151#define set_temp(value, reg) \
152static ssize_t set_##value(struct device *dev, struct device_attribute *attr, const char *buf, \
153 size_t count) \
154{ \
155 struct i2c_client *client = to_i2c_client(dev); \
156 struct lm92_data *data = i2c_get_clientdata(client); \
157 long val = simple_strtol(buf, NULL, 10); \
158 \
159 mutex_lock(&data->update_lock); \
160 data->value = TEMP_TO_REG(val); \
161 i2c_smbus_write_word_data(client, reg, swab16(data->value)); \
162 mutex_unlock(&data->update_lock); \
163 return count; \
164}
165set_temp(temp1_crit, LM92_REG_TEMP_CRIT);
166set_temp(temp1_min, LM92_REG_TEMP_LOW);
167set_temp(temp1_max, LM92_REG_TEMP_HIGH);
168
169static ssize_t show_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, char *buf)
170{
171 struct lm92_data *data = lm92_update_device(dev);
172 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_crit)
173 - TEMP_FROM_REG(data->temp1_hyst));
174}
175static ssize_t show_temp1_max_hyst(struct device *dev, struct device_attribute *attr, char *buf)
176{
177 struct lm92_data *data = lm92_update_device(dev);
178 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_max)
179 - TEMP_FROM_REG(data->temp1_hyst));
180}
181static ssize_t show_temp1_min_hyst(struct device *dev, struct device_attribute *attr, char *buf)
182{
183 struct lm92_data *data = lm92_update_device(dev);
184 return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp1_min)
185 + TEMP_FROM_REG(data->temp1_hyst));
186}
187
188static ssize_t set_temp1_crit_hyst(struct device *dev, struct device_attribute *attr, const char *buf,
189 size_t count)
190{
191 struct i2c_client *client = to_i2c_client(dev);
192 struct lm92_data *data = i2c_get_clientdata(client);
193 long val = simple_strtol(buf, NULL, 10);
194
195 mutex_lock(&data->update_lock);
196 data->temp1_hyst = TEMP_FROM_REG(data->temp1_crit) - val;
197 i2c_smbus_write_word_data(client, LM92_REG_TEMP_HYST,
198 swab16(TEMP_TO_REG(data->temp1_hyst)));
199 mutex_unlock(&data->update_lock);
200 return count;
201}
202
203static ssize_t show_alarms(struct device *dev, struct device_attribute *attr, char *buf)
204{
205 struct lm92_data *data = lm92_update_device(dev);
206 return sprintf(buf, "%d\n", ALARMS_FROM_REG(data->temp1_input));
207}
208
209static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
210 char *buf)
211{
212 int bitnr = to_sensor_dev_attr(attr)->index;
213 struct lm92_data *data = lm92_update_device(dev);
214 return sprintf(buf, "%d\n", (data->temp1_input >> bitnr) & 1);
215}
216
217static DEVICE_ATTR(temp1_input, S_IRUGO, show_temp1_input, NULL);
218static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_temp1_crit,
219 set_temp1_crit);
220static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_temp1_crit_hyst,
221 set_temp1_crit_hyst);
222static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, show_temp1_min,
223 set_temp1_min);
224static DEVICE_ATTR(temp1_min_hyst, S_IRUGO, show_temp1_min_hyst, NULL);
225static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp1_max,
226 set_temp1_max);
227static DEVICE_ATTR(temp1_max_hyst, S_IRUGO, show_temp1_max_hyst, NULL);
228static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
229static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 2);
230static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 0);
231static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 1);
232
233
234/*
235 * Detection and registration
236 */
237
238static void lm92_init_client(struct i2c_client *client)
239{
240 u8 config;
241
242 /* Start the conversions if needed */
243 config = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
244 if (config & 0x01)
245 i2c_smbus_write_byte_data(client, LM92_REG_CONFIG,
246 config & 0xFE);
247}
248
249/* The MAX6635 has no identification register, so we have to use tricks
250 to identify it reliably. This is somewhat slow.
251 Note that we do NOT rely on the 2 MSB of the configuration register
252 always reading 0, as suggested by the datasheet, because it was once
253 reported not to be true. */
254static int max6635_check(struct i2c_client *client)
255{
256 u16 temp_low, temp_high, temp_hyst, temp_crit;
257 u8 conf;
258 int i;
259
260 /* No manufacturer ID register, so a read from this address will
261 always return the last read value. */
262 temp_low = i2c_smbus_read_word_data(client, LM92_REG_TEMP_LOW);
263 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_low)
264 return 0;
265 temp_high = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HIGH);
266 if (i2c_smbus_read_word_data(client, LM92_REG_MAN_ID) != temp_high)
267 return 0;
268
269 /* Limits are stored as integer values (signed, 9-bit). */
270 if ((temp_low & 0x7f00) || (temp_high & 0x7f00))
271 return 0;
272 temp_hyst = i2c_smbus_read_word_data(client, LM92_REG_TEMP_HYST);
273 temp_crit = i2c_smbus_read_word_data(client, LM92_REG_TEMP_CRIT);
274 if ((temp_hyst & 0x7f00) || (temp_crit & 0x7f00))
275 return 0;
276
277 /* Registers addresses were found to cycle over 16-byte boundaries.
278 We don't test all registers with all offsets so as to save some
279 reads and time, but this should still be sufficient to dismiss
280 non-MAX6635 chips. */
281 conf = i2c_smbus_read_byte_data(client, LM92_REG_CONFIG);
282 for (i=16; i<96; i*=2) {
283 if (temp_hyst != i2c_smbus_read_word_data(client,
284 LM92_REG_TEMP_HYST + i - 16)
285 || temp_crit != i2c_smbus_read_word_data(client,
286 LM92_REG_TEMP_CRIT + i)
287 || temp_low != i2c_smbus_read_word_data(client,
288 LM92_REG_TEMP_LOW + i + 16)
289 || temp_high != i2c_smbus_read_word_data(client,
290 LM92_REG_TEMP_HIGH + i + 32)
291 || conf != i2c_smbus_read_byte_data(client,
292 LM92_REG_CONFIG + i))
293 return 0;
294 }
295
296 return 1;
297}
298
299static struct attribute *lm92_attributes[] = {
300 &dev_attr_temp1_input.attr,
301 &dev_attr_temp1_crit.attr,
302 &dev_attr_temp1_crit_hyst.attr,
303 &dev_attr_temp1_min.attr,
304 &dev_attr_temp1_min_hyst.attr,
305 &dev_attr_temp1_max.attr,
306 &dev_attr_temp1_max_hyst.attr,
307 &dev_attr_alarms.attr,
308 &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
309 &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
310 &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
311 NULL
312};
313
314static const struct attribute_group lm92_group = {
315 .attrs = lm92_attributes,
316};
317
318/* Return 0 if detection is successful, -ENODEV otherwise */
319static int lm92_detect(struct i2c_client *new_client,
320 struct i2c_board_info *info)
321{
322 struct i2c_adapter *adapter = new_client->adapter;
323 u8 config;
324 u16 man_id;
325
326 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
327 | I2C_FUNC_SMBUS_WORD_DATA))
328 return -ENODEV;
329
330 config = i2c_smbus_read_byte_data(new_client, LM92_REG_CONFIG);
331 man_id = i2c_smbus_read_word_data(new_client, LM92_REG_MAN_ID);
332
333 if ((config & 0xe0) == 0x00 && man_id == 0x0180)
334 pr_info("lm92: Found National Semiconductor LM92 chip\n");
335 else if (max6635_check(new_client))
336 pr_info("lm92: Found Maxim MAX6635 chip\n");
337 else
338 return -ENODEV;
339
340 strlcpy(info->type, "lm92", I2C_NAME_SIZE);
341
342 return 0;
343}
344
345static int lm92_probe(struct i2c_client *new_client,
346 const struct i2c_device_id *id)
347{
348 struct lm92_data *data;
349 int err;
350
351 data = kzalloc(sizeof(struct lm92_data), GFP_KERNEL);
352 if (!data) {
353 err = -ENOMEM;
354 goto exit;
355 }
356
357 i2c_set_clientdata(new_client, data);
358 data->valid = 0;
359 mutex_init(&data->update_lock);
360
361 /* Initialize the chipset */
362 lm92_init_client(new_client);
363
364 /* Register sysfs hooks */
365 if ((err = sysfs_create_group(&new_client->dev.kobj, &lm92_group)))
366 goto exit_free;
367
368 data->hwmon_dev = hwmon_device_register(&new_client->dev);
369 if (IS_ERR(data->hwmon_dev)) {
370 err = PTR_ERR(data->hwmon_dev);
371 goto exit_remove;
372 }
373
374 return 0;
375
376exit_remove:
377 sysfs_remove_group(&new_client->dev.kobj, &lm92_group);
378exit_free:
379 kfree(data);
380exit:
381 return err;
382}
383
384static int lm92_remove(struct i2c_client *client)
385{
386 struct lm92_data *data = i2c_get_clientdata(client);
387
388 hwmon_device_unregister(data->hwmon_dev);
389 sysfs_remove_group(&client->dev.kobj, &lm92_group);
390
391 kfree(data);
392 return 0;
393}
394
395
396/*
397 * Module and driver stuff
398 */
399
400static const struct i2c_device_id lm92_id[] = {
401 { "lm92", 0 },
402 /* max6635 could be added here */
403 { }
404};
405MODULE_DEVICE_TABLE(i2c, lm92_id);
406
407static struct i2c_driver lm92_driver = {
408 .class = I2C_CLASS_HWMON,
409 .driver = {
410 .name = "lm92",
411 },
412 .probe = lm92_probe,
413 .remove = lm92_remove,
414 .id_table = lm92_id,
415 .detect = lm92_detect,
416 .address_list = normal_i2c,
417};
418
419static int __init sensors_lm92_init(void)
420{
421 return i2c_add_driver(&lm92_driver);
422}
423
424static void __exit sensors_lm92_exit(void)
425{
426 i2c_del_driver(&lm92_driver);
427}
428
429MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
430MODULE_DESCRIPTION("LM92/MAX6635 driver");
431MODULE_LICENSE("GPL");
432
433module_init(sensors_lm92_init);
434module_exit(sensors_lm92_exit);
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/err.h>
31#include <linux/hwmon.h>
32#include <linux/i2c.h>
33#include <linux/init.h>
34#include <linux/module.h>
35#include <linux/mutex.h>
36#include <linux/regmap.h>
37#include <linux/slab.h>
38
39/*
40 * The LM92 and MAX6635 have 2 two-state pins for address selection,
41 * resulting in 4 possible addresses.
42 */
43static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4b,
44 I2C_CLIENT_END };
45/* The LM92 registers */
46#define LM92_REG_CONFIG 0x01 /* 8-bit, RW */
47#define LM92_REG_TEMP 0x00 /* 16-bit, RO */
48#define LM92_REG_TEMP_HYST 0x02 /* 16-bit, RW */
49#define LM92_REG_TEMP_CRIT 0x03 /* 16-bit, RW */
50#define LM92_REG_TEMP_LOW 0x04 /* 16-bit, RW */
51#define LM92_REG_TEMP_HIGH 0x05 /* 16-bit, RW */
52#define LM92_REG_MAN_ID 0x07 /* 16-bit, RO, LM92 only */
53
54/*
55 * The LM92 uses signed 13-bit values with LSB = 0.0625 degree Celsius,
56 * left-justified in 16-bit registers. No rounding is done, with such
57 * a resolution it's just not worth it. Note that the MAX6635 doesn't
58 * make use of the 4 lower bits for limits (i.e. effective resolution
59 * for limits is 1 degree Celsius).
60 */
61static inline int TEMP_FROM_REG(s16 reg)
62{
63 return reg / 8 * 625 / 10;
64}
65
66static inline s16 TEMP_TO_REG(long val, int resolution)
67{
68 val = clamp_val(val, -60000, 160000);
69 return DIV_ROUND_CLOSEST(val << (resolution - 9), 1000) << (16 - resolution);
70}
71
72/* Alarm flags are stored in the 3 LSB of the temperature register */
73static inline u8 ALARMS_FROM_REG(s16 reg)
74{
75 return reg & 0x0007;
76}
77
78/* Client data (each client gets its own) */
79struct lm92_data {
80 struct regmap *regmap;
81 struct mutex update_lock;
82 int resolution;
83};
84
85static int lm92_temp_read(struct lm92_data *data, u32 attr, int channel, long *val)
86{
87 int reg = -1, hyst_reg = -1, alarm_bit = 0;
88 struct regmap *regmap = data->regmap;
89 u32 temp;
90 int ret;
91
92 switch (attr) {
93 case hwmon_temp_input:
94 reg = LM92_REG_TEMP;
95 break;
96 case hwmon_temp_min:
97 reg = LM92_REG_TEMP_LOW;
98 break;
99 case hwmon_temp_max:
100 reg = LM92_REG_TEMP_HIGH;
101 break;
102 case hwmon_temp_crit:
103 reg = LM92_REG_TEMP_CRIT;
104 break;
105 case hwmon_temp_min_hyst:
106 hyst_reg = LM92_REG_TEMP_LOW;
107 break;
108 case hwmon_temp_max_hyst:
109 hyst_reg = LM92_REG_TEMP_HIGH;
110 break;
111 case hwmon_temp_crit_hyst:
112 hyst_reg = LM92_REG_TEMP_CRIT;
113 break;
114 case hwmon_temp_min_alarm:
115 alarm_bit = 0;
116 break;
117 case hwmon_temp_max_alarm:
118 alarm_bit = 1;
119 break;
120 case hwmon_temp_crit_alarm:
121 alarm_bit = 2;
122 break;
123 default:
124 return -EOPNOTSUPP;
125 }
126 if (reg >= 0) {
127 ret = regmap_read(regmap, reg, &temp);
128 if (ret < 0)
129 return ret;
130 *val = TEMP_FROM_REG(temp);
131 } else if (hyst_reg >= 0) {
132 u32 regs[2] = { hyst_reg, LM92_REG_TEMP_HYST };
133 u16 regvals[2];
134
135 ret = regmap_multi_reg_read(regmap, regs, regvals, 2);
136 if (ret)
137 return ret;
138 if (attr == hwmon_temp_min_hyst)
139 *val = TEMP_FROM_REG(regvals[0]) + TEMP_FROM_REG(regvals[1]);
140 else
141 *val = TEMP_FROM_REG(regvals[0]) - TEMP_FROM_REG(regvals[1]);
142 } else {
143 ret = regmap_read(regmap, LM92_REG_TEMP, &temp);
144 if (ret)
145 return ret;
146 *val = !!(temp & BIT(alarm_bit));
147 }
148 return 0;
149}
150
151static int lm92_chip_read(struct lm92_data *data, u32 attr, long *val)
152{
153 u32 temp;
154 int ret;
155
156 switch (attr) {
157 case hwmon_chip_alarms:
158 ret = regmap_read(data->regmap, LM92_REG_TEMP, &temp);
159 if (ret)
160 return ret;
161 *val = ALARMS_FROM_REG(temp);
162 break;
163 default:
164 return -EOPNOTSUPP;
165 }
166 return 0;
167}
168
169static int lm92_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
170 int channel, long *val)
171{
172 struct lm92_data *data = dev_get_drvdata(dev);
173
174 switch (type) {
175 case hwmon_chip:
176 return lm92_chip_read(data, attr, val);
177 case hwmon_temp:
178 return lm92_temp_read(data, attr, channel, val);
179 default:
180 return -EOPNOTSUPP;
181 }
182}
183
184static int lm92_temp_write(struct lm92_data *data, u32 attr, long val)
185{
186 struct regmap *regmap = data->regmap;
187 int reg, err;
188 u32 temp;
189
190 switch (attr) {
191 case hwmon_temp_min:
192 reg = LM92_REG_TEMP_LOW;
193 break;
194 case hwmon_temp_max:
195 reg = LM92_REG_TEMP_HIGH;
196 break;
197 case hwmon_temp_crit:
198 reg = LM92_REG_TEMP_CRIT;
199 break;
200 case hwmon_temp_crit_hyst:
201 val = clamp_val(val, -120000, 220000);
202 mutex_lock(&data->update_lock);
203 err = regmap_read(regmap, LM92_REG_TEMP_CRIT, &temp);
204 if (err)
205 goto unlock;
206 val = TEMP_TO_REG(TEMP_FROM_REG(temp) - val, data->resolution);
207 err = regmap_write(regmap, LM92_REG_TEMP_HYST, val);
208unlock:
209 mutex_unlock(&data->update_lock);
210 return err;
211 default:
212 return -EOPNOTSUPP;
213 }
214 return regmap_write(regmap, reg, TEMP_TO_REG(val, data->resolution));
215}
216
217static int lm92_write(struct device *dev, enum hwmon_sensor_types type,
218 u32 attr, int channel, long val)
219{
220 struct lm92_data *data = dev_get_drvdata(dev);
221
222 switch (type) {
223 case hwmon_temp:
224 return lm92_temp_write(data, attr, val);
225 default:
226 return -EOPNOTSUPP;
227 }
228}
229
230static umode_t lm92_is_visible(const void *_data, enum hwmon_sensor_types type,
231 u32 attr, int channel)
232{
233 switch (type) {
234 case hwmon_chip:
235 switch (attr) {
236 case hwmon_chip_alarms:
237 return 0444;
238 default:
239 break;
240 }
241 break;
242 case hwmon_temp:
243 switch (attr) {
244 case hwmon_temp_min:
245 case hwmon_temp_max:
246 case hwmon_temp_crit:
247 case hwmon_temp_crit_hyst:
248 return 0644;
249 case hwmon_temp_input:
250 case hwmon_temp_min_hyst:
251 case hwmon_temp_max_hyst:
252 case hwmon_temp_min_alarm:
253 case hwmon_temp_max_alarm:
254 case hwmon_temp_crit_alarm:
255 return 0444;
256 default:
257 break;
258 }
259 break;
260 default:
261 break;
262 }
263 return 0;
264}
265
266static const struct hwmon_channel_info * const lm92_info[] = {
267 HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
268 HWMON_CHANNEL_INFO(temp,
269 HWMON_T_INPUT |
270 HWMON_T_MIN | HWMON_T_MIN_HYST |
271 HWMON_T_MAX | HWMON_T_MAX_HYST |
272 HWMON_T_CRIT | HWMON_T_CRIT_HYST |
273 HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM |
274 HWMON_T_CRIT_ALARM),
275 NULL
276};
277
278static const struct hwmon_ops lm92_hwmon_ops = {
279 .is_visible = lm92_is_visible,
280 .read = lm92_read,
281 .write = lm92_write,
282};
283
284static const struct hwmon_chip_info lm92_chip_info = {
285 .ops = &lm92_hwmon_ops,
286 .info = lm92_info,
287};
288
289/*
290 * Detection and registration
291 */
292
293static int lm92_init_client(struct regmap *regmap)
294{
295 return regmap_clear_bits(regmap, LM92_REG_CONFIG, 0x01);
296}
297
298/* Return 0 if detection is successful, -ENODEV otherwise */
299static int lm92_detect(struct i2c_client *new_client,
300 struct i2c_board_info *info)
301{
302 struct i2c_adapter *adapter = new_client->adapter;
303 u8 config_addr = LM92_REG_CONFIG;
304 u8 man_id_addr = LM92_REG_MAN_ID;
305 int i, regval;
306
307 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA
308 | I2C_FUNC_SMBUS_WORD_DATA))
309 return -ENODEV;
310
311 /*
312 * Register values repeat with multiples of 8.
313 * Read twice to improve detection accuracy.
314 */
315 for (i = 0; i < 2; i++) {
316 regval = i2c_smbus_read_word_data(new_client, man_id_addr);
317 if (regval != 0x0180)
318 return -ENODEV;
319 regval = i2c_smbus_read_byte_data(new_client, config_addr);
320 if (regval < 0 || (regval & 0xe0))
321 return -ENODEV;
322 config_addr += 8;
323 man_id_addr += 8;
324 }
325
326 strscpy(info->type, "lm92", I2C_NAME_SIZE);
327
328 return 0;
329}
330
331/* regmap */
332
333static int lm92_reg_read(void *context, unsigned int reg, unsigned int *val)
334{
335 int ret;
336
337 if (reg == LM92_REG_CONFIG)
338 ret = i2c_smbus_read_byte_data(context, reg);
339 else
340 ret = i2c_smbus_read_word_swapped(context, reg);
341 if (ret < 0)
342 return ret;
343
344 *val = ret;
345 return 0;
346}
347
348static int lm92_reg_write(void *context, unsigned int reg, unsigned int val)
349{
350 if (reg == LM92_REG_CONFIG)
351 return i2c_smbus_write_byte_data(context, LM92_REG_CONFIG, val);
352
353 return i2c_smbus_write_word_swapped(context, reg, val);
354}
355
356static bool lm92_regmap_is_volatile(struct device *dev, unsigned int reg)
357{
358 return reg == LM92_REG_TEMP;
359}
360
361static bool lm92_regmap_is_writeable(struct device *dev, unsigned int reg)
362{
363 return reg >= LM92_REG_CONFIG;
364}
365
366static const struct regmap_config lm92_regmap_config = {
367 .reg_bits = 8,
368 .val_bits = 16,
369 .max_register = LM92_REG_TEMP_HIGH,
370 .cache_type = REGCACHE_MAPLE,
371 .volatile_reg = lm92_regmap_is_volatile,
372 .writeable_reg = lm92_regmap_is_writeable,
373};
374
375static const struct regmap_bus lm92_regmap_bus = {
376 .reg_write = lm92_reg_write,
377 .reg_read = lm92_reg_read,
378};
379
380static int lm92_probe(struct i2c_client *client)
381{
382 struct device *dev = &client->dev;
383 struct device *hwmon_dev;
384 struct lm92_data *data;
385 struct regmap *regmap;
386 int err;
387
388 regmap = devm_regmap_init(dev, &lm92_regmap_bus, client,
389 &lm92_regmap_config);
390 if (IS_ERR(regmap))
391 return PTR_ERR(regmap);
392
393 data = devm_kzalloc(dev, sizeof(struct lm92_data), GFP_KERNEL);
394 if (!data)
395 return -ENOMEM;
396
397 data->regmap = regmap;
398 data->resolution = (unsigned long)i2c_get_match_data(client);
399 mutex_init(&data->update_lock);
400
401 /* Initialize the chipset */
402 err = lm92_init_client(regmap);
403 if (err)
404 return err;
405
406 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data,
407 &lm92_chip_info, NULL);
408 return PTR_ERR_OR_ZERO(hwmon_dev);
409}
410
411/*
412 * Module and driver stuff
413 */
414
415/* .driver_data is limit register resolution */
416static const struct i2c_device_id lm92_id[] = {
417 { "lm92", 13 },
418 { "max6635", 9 },
419 { }
420};
421MODULE_DEVICE_TABLE(i2c, lm92_id);
422
423static struct i2c_driver lm92_driver = {
424 .class = I2C_CLASS_HWMON,
425 .driver = {
426 .name = "lm92",
427 },
428 .probe = lm92_probe,
429 .id_table = lm92_id,
430 .detect = lm92_detect,
431 .address_list = normal_i2c,
432};
433
434module_i2c_driver(lm92_driver);
435
436MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
437MODULE_DESCRIPTION("LM92/MAX6635 driver");
438MODULE_LICENSE("GPL");