xref: /openbmc/linux/drivers/hwmon/lm83.c (revision c3813d6af177fab19e322f3114b1f64fbcf08d71)
1 /*
2  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
3  *          monitoring
4  * Copyright (C) 2003-2009  Jean Delvare <khali@linux-fr.org>
5  *
6  * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
7  * a sensor chip made by National Semiconductor. It reports up to four
8  * temperatures (its own plus up to three external ones) with a 1 deg
9  * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
10  * from National's website at:
11  *   http://www.national.com/pf/LM/LM83.html
12  * Since the datasheet omits to give the chip stepping code, I give it
13  * here: 0x03 (at register 0xff).
14  *
15  * Also supports the LM82 temp sensor, which is basically a stripped down
16  * model of the LM83.  Datasheet is here:
17  * http://www.national.com/pf/LM/LM82.html
18  *
19  * This program is free software; you can redistribute it and/or modify
20  * it under the terms of the GNU General Public License as published by
21  * the Free Software Foundation; either version 2 of the License, or
22  * (at your option) any later version.
23  *
24  * This program is distributed in the hope that it will be useful,
25  * but WITHOUT ANY WARRANTY; without even the implied warranty of
26  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
27  * GNU General Public License for more details.
28  *
29  * You should have received a copy of the GNU General Public License
30  * along with this program; if not, write to the Free Software
31  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
32  */
33 
34 #include <linux/module.h>
35 #include <linux/init.h>
36 #include <linux/slab.h>
37 #include <linux/jiffies.h>
38 #include <linux/i2c.h>
39 #include <linux/hwmon-sysfs.h>
40 #include <linux/hwmon.h>
41 #include <linux/err.h>
42 #include <linux/mutex.h>
43 #include <linux/sysfs.h>
44 
45 /*
46  * Addresses to scan
47  * Address is selected using 2 three-level pins, resulting in 9 possible
48  * addresses.
49  */
50 
51 static const unsigned short normal_i2c[] = {
52 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
53 
54 /*
55  * Insmod parameters
56  */
57 
58 I2C_CLIENT_INSMOD_2(lm83, lm82);
59 
60 /*
61  * The LM83 registers
62  * Manufacturer ID is 0x01 for National Semiconductor.
63  */
64 
65 #define LM83_REG_R_MAN_ID		0xFE
66 #define LM83_REG_R_CHIP_ID		0xFF
67 #define LM83_REG_R_CONFIG		0x03
68 #define LM83_REG_W_CONFIG		0x09
69 #define LM83_REG_R_STATUS1		0x02
70 #define LM83_REG_R_STATUS2		0x35
71 #define LM83_REG_R_LOCAL_TEMP		0x00
72 #define LM83_REG_R_LOCAL_HIGH		0x05
73 #define LM83_REG_W_LOCAL_HIGH		0x0B
74 #define LM83_REG_R_REMOTE1_TEMP		0x30
75 #define LM83_REG_R_REMOTE1_HIGH		0x38
76 #define LM83_REG_W_REMOTE1_HIGH		0x50
77 #define LM83_REG_R_REMOTE2_TEMP		0x01
78 #define LM83_REG_R_REMOTE2_HIGH		0x07
79 #define LM83_REG_W_REMOTE2_HIGH		0x0D
80 #define LM83_REG_R_REMOTE3_TEMP		0x31
81 #define LM83_REG_R_REMOTE3_HIGH		0x3A
82 #define LM83_REG_W_REMOTE3_HIGH		0x52
83 #define LM83_REG_R_TCRIT		0x42
84 #define LM83_REG_W_TCRIT		0x5A
85 
86 /*
87  * Conversions and various macros
88  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
89  */
90 
91 #define TEMP_FROM_REG(val)	((val) * 1000)
92 #define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
93 				 (val) >= 127000 ? 127 : \
94 				 (val) < 0 ? ((val) - 500) / 1000 : \
95 				 ((val) + 500) / 1000)
96 
97 static const u8 LM83_REG_R_TEMP[] = {
98 	LM83_REG_R_LOCAL_TEMP,
99 	LM83_REG_R_REMOTE1_TEMP,
100 	LM83_REG_R_REMOTE2_TEMP,
101 	LM83_REG_R_REMOTE3_TEMP,
102 	LM83_REG_R_LOCAL_HIGH,
103 	LM83_REG_R_REMOTE1_HIGH,
104 	LM83_REG_R_REMOTE2_HIGH,
105 	LM83_REG_R_REMOTE3_HIGH,
106 	LM83_REG_R_TCRIT,
107 };
108 
109 static const u8 LM83_REG_W_HIGH[] = {
110 	LM83_REG_W_LOCAL_HIGH,
111 	LM83_REG_W_REMOTE1_HIGH,
112 	LM83_REG_W_REMOTE2_HIGH,
113 	LM83_REG_W_REMOTE3_HIGH,
114 	LM83_REG_W_TCRIT,
115 };
116 
117 /*
118  * Functions declaration
119  */
120 
121 static int lm83_detect(struct i2c_client *new_client,
122 		       struct i2c_board_info *info);
123 static int lm83_probe(struct i2c_client *client,
124 		      const struct i2c_device_id *id);
125 static int lm83_remove(struct i2c_client *client);
126 static struct lm83_data *lm83_update_device(struct device *dev);
127 
128 /*
129  * Driver data (common to all clients)
130  */
131 
132 static const struct i2c_device_id lm83_id[] = {
133 	{ "lm83", lm83 },
134 	{ "lm82", lm82 },
135 	{ }
136 };
137 MODULE_DEVICE_TABLE(i2c, lm83_id);
138 
139 static struct i2c_driver lm83_driver = {
140 	.class		= I2C_CLASS_HWMON,
141 	.driver = {
142 		.name	= "lm83",
143 	},
144 	.probe		= lm83_probe,
145 	.remove		= lm83_remove,
146 	.id_table	= lm83_id,
147 	.detect		= lm83_detect,
148 	.address_list	= normal_i2c,
149 };
150 
151 /*
152  * Client data (each client gets its own)
153  */
154 
155 struct lm83_data {
156 	struct device *hwmon_dev;
157 	struct mutex update_lock;
158 	char valid; /* zero until following fields are valid */
159 	unsigned long last_updated; /* in jiffies */
160 
161 	/* registers values */
162 	s8 temp[9];	/* 0..3: input 1-4,
163 			   4..7: high limit 1-4,
164 			   8   : critical limit */
165 	u16 alarms; /* bitvector, combined */
166 };
167 
168 /*
169  * Sysfs stuff
170  */
171 
172 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
173 			 char *buf)
174 {
175 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
176 	struct lm83_data *data = lm83_update_device(dev);
177 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
178 }
179 
180 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
181 			const char *buf, size_t count)
182 {
183 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
184 	struct i2c_client *client = to_i2c_client(dev);
185 	struct lm83_data *data = i2c_get_clientdata(client);
186 	long val = simple_strtol(buf, NULL, 10);
187 	int nr = attr->index;
188 
189 	mutex_lock(&data->update_lock);
190 	data->temp[nr] = TEMP_TO_REG(val);
191 	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
192 				  data->temp[nr]);
193 	mutex_unlock(&data->update_lock);
194 	return count;
195 }
196 
197 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
198 			   char *buf)
199 {
200 	struct lm83_data *data = lm83_update_device(dev);
201 	return sprintf(buf, "%d\n", data->alarms);
202 }
203 
204 static ssize_t show_alarm(struct device *dev, struct device_attribute
205 			  *devattr, char *buf)
206 {
207 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
208 	struct lm83_data *data = lm83_update_device(dev);
209 	int bitnr = attr->index;
210 
211 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
212 }
213 
214 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
215 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
216 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
217 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
218 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
219 	set_temp, 4);
220 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
221 	set_temp, 5);
222 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
223 	set_temp, 6);
224 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
225 	set_temp, 7);
226 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
227 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
228 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
229 	set_temp, 8);
230 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
231 
232 /* Individual alarm files */
233 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
234 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
235 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
236 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
237 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
238 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
239 static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
240 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
241 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
242 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
243 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
244 /* Raw alarm file for compatibility */
245 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
246 
247 static struct attribute *lm83_attributes[] = {
248 	&sensor_dev_attr_temp1_input.dev_attr.attr,
249 	&sensor_dev_attr_temp3_input.dev_attr.attr,
250 	&sensor_dev_attr_temp1_max.dev_attr.attr,
251 	&sensor_dev_attr_temp3_max.dev_attr.attr,
252 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
253 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
254 
255 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
256 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
257 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
258 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
259 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
260 	&dev_attr_alarms.attr,
261 	NULL
262 };
263 
264 static const struct attribute_group lm83_group = {
265 	.attrs = lm83_attributes,
266 };
267 
268 static struct attribute *lm83_attributes_opt[] = {
269 	&sensor_dev_attr_temp2_input.dev_attr.attr,
270 	&sensor_dev_attr_temp4_input.dev_attr.attr,
271 	&sensor_dev_attr_temp2_max.dev_attr.attr,
272 	&sensor_dev_attr_temp4_max.dev_attr.attr,
273 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
274 	&sensor_dev_attr_temp4_crit.dev_attr.attr,
275 
276 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
277 	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
278 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
279 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
280 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
281 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
282 	NULL
283 };
284 
285 static const struct attribute_group lm83_group_opt = {
286 	.attrs = lm83_attributes_opt,
287 };
288 
289 /*
290  * Real code
291  */
292 
293 /* Return 0 if detection is successful, -ENODEV otherwise */
294 static int lm83_detect(struct i2c_client *new_client,
295 		       struct i2c_board_info *info)
296 {
297 	struct i2c_adapter *adapter = new_client->adapter;
298 	const char *name;
299 	u8 man_id, chip_id;
300 
301 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
302 		return -ENODEV;
303 
304 	/* Detection */
305 	if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
306 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
307 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
308 		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
309 			new_client->addr);
310 		return -ENODEV;
311 	}
312 
313 	/* Identification */
314 	man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
315 	if (man_id != 0x01)	/* National Semiconductor */
316 		return -ENODEV;
317 
318 	chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
319 	switch (chip_id) {
320 	case 0x03:
321 		name = "lm83";
322 		break;
323 	case 0x01:
324 		name = "lm82";
325 		break;
326 	default:
327 		/* identification failed */
328 		dev_info(&adapter->dev,
329 			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
330 			 man_id, chip_id);
331 		return -ENODEV;
332 	}
333 
334 	strlcpy(info->type, name, I2C_NAME_SIZE);
335 
336 	return 0;
337 }
338 
339 static int lm83_probe(struct i2c_client *new_client,
340 		      const struct i2c_device_id *id)
341 {
342 	struct lm83_data *data;
343 	int err;
344 
345 	data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL);
346 	if (!data) {
347 		err = -ENOMEM;
348 		goto exit;
349 	}
350 
351 	i2c_set_clientdata(new_client, data);
352 	data->valid = 0;
353 	mutex_init(&data->update_lock);
354 
355 	/*
356 	 * Register sysfs hooks
357 	 * The LM82 can only monitor one external diode which is
358 	 * at the same register as the LM83 temp3 entry - so we
359 	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
360 	 */
361 
362 	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm83_group)))
363 		goto exit_free;
364 
365 	if (id->driver_data == lm83) {
366 		if ((err = sysfs_create_group(&new_client->dev.kobj,
367 					      &lm83_group_opt)))
368 			goto exit_remove_files;
369 	}
370 
371 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
372 	if (IS_ERR(data->hwmon_dev)) {
373 		err = PTR_ERR(data->hwmon_dev);
374 		goto exit_remove_files;
375 	}
376 
377 	return 0;
378 
379 exit_remove_files:
380 	sysfs_remove_group(&new_client->dev.kobj, &lm83_group);
381 	sysfs_remove_group(&new_client->dev.kobj, &lm83_group_opt);
382 exit_free:
383 	kfree(data);
384 exit:
385 	return err;
386 }
387 
388 static int lm83_remove(struct i2c_client *client)
389 {
390 	struct lm83_data *data = i2c_get_clientdata(client);
391 
392 	hwmon_device_unregister(data->hwmon_dev);
393 	sysfs_remove_group(&client->dev.kobj, &lm83_group);
394 	sysfs_remove_group(&client->dev.kobj, &lm83_group_opt);
395 
396 	kfree(data);
397 	return 0;
398 }
399 
400 static struct lm83_data *lm83_update_device(struct device *dev)
401 {
402 	struct i2c_client *client = to_i2c_client(dev);
403 	struct lm83_data *data = i2c_get_clientdata(client);
404 
405 	mutex_lock(&data->update_lock);
406 
407 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
408 		int nr;
409 
410 		dev_dbg(&client->dev, "Updating lm83 data.\n");
411 		for (nr = 0; nr < 9; nr++) {
412 			data->temp[nr] =
413 			    i2c_smbus_read_byte_data(client,
414 			    LM83_REG_R_TEMP[nr]);
415 		}
416 		data->alarms =
417 		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
418 		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
419 		    << 8);
420 
421 		data->last_updated = jiffies;
422 		data->valid = 1;
423 	}
424 
425 	mutex_unlock(&data->update_lock);
426 
427 	return data;
428 }
429 
430 static int __init sensors_lm83_init(void)
431 {
432 	return i2c_add_driver(&lm83_driver);
433 }
434 
435 static void __exit sensors_lm83_exit(void)
436 {
437 	i2c_del_driver(&lm83_driver);
438 }
439 
440 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
441 MODULE_DESCRIPTION("LM83 driver");
442 MODULE_LICENSE("GPL");
443 
444 module_init(sensors_lm83_init);
445 module_exit(sensors_lm83_exit);
446