xref: /openbmc/linux/drivers/hwmon/lm83.c (revision 63dc02bd)
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 enum chips { lm83, lm82 };
55 
56 /*
57  * The LM83 registers
58  * Manufacturer ID is 0x01 for National Semiconductor.
59  */
60 
61 #define LM83_REG_R_MAN_ID		0xFE
62 #define LM83_REG_R_CHIP_ID		0xFF
63 #define LM83_REG_R_CONFIG		0x03
64 #define LM83_REG_W_CONFIG		0x09
65 #define LM83_REG_R_STATUS1		0x02
66 #define LM83_REG_R_STATUS2		0x35
67 #define LM83_REG_R_LOCAL_TEMP		0x00
68 #define LM83_REG_R_LOCAL_HIGH		0x05
69 #define LM83_REG_W_LOCAL_HIGH		0x0B
70 #define LM83_REG_R_REMOTE1_TEMP		0x30
71 #define LM83_REG_R_REMOTE1_HIGH		0x38
72 #define LM83_REG_W_REMOTE1_HIGH		0x50
73 #define LM83_REG_R_REMOTE2_TEMP		0x01
74 #define LM83_REG_R_REMOTE2_HIGH		0x07
75 #define LM83_REG_W_REMOTE2_HIGH		0x0D
76 #define LM83_REG_R_REMOTE3_TEMP		0x31
77 #define LM83_REG_R_REMOTE3_HIGH		0x3A
78 #define LM83_REG_W_REMOTE3_HIGH		0x52
79 #define LM83_REG_R_TCRIT		0x42
80 #define LM83_REG_W_TCRIT		0x5A
81 
82 /*
83  * Conversions and various macros
84  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
85  */
86 
87 #define TEMP_FROM_REG(val)	((val) * 1000)
88 #define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
89 				 (val) >= 127000 ? 127 : \
90 				 (val) < 0 ? ((val) - 500) / 1000 : \
91 				 ((val) + 500) / 1000)
92 
93 static const u8 LM83_REG_R_TEMP[] = {
94 	LM83_REG_R_LOCAL_TEMP,
95 	LM83_REG_R_REMOTE1_TEMP,
96 	LM83_REG_R_REMOTE2_TEMP,
97 	LM83_REG_R_REMOTE3_TEMP,
98 	LM83_REG_R_LOCAL_HIGH,
99 	LM83_REG_R_REMOTE1_HIGH,
100 	LM83_REG_R_REMOTE2_HIGH,
101 	LM83_REG_R_REMOTE3_HIGH,
102 	LM83_REG_R_TCRIT,
103 };
104 
105 static const u8 LM83_REG_W_HIGH[] = {
106 	LM83_REG_W_LOCAL_HIGH,
107 	LM83_REG_W_REMOTE1_HIGH,
108 	LM83_REG_W_REMOTE2_HIGH,
109 	LM83_REG_W_REMOTE3_HIGH,
110 	LM83_REG_W_TCRIT,
111 };
112 
113 /*
114  * Functions declaration
115  */
116 
117 static int lm83_detect(struct i2c_client *new_client,
118 		       struct i2c_board_info *info);
119 static int lm83_probe(struct i2c_client *client,
120 		      const struct i2c_device_id *id);
121 static int lm83_remove(struct i2c_client *client);
122 static struct lm83_data *lm83_update_device(struct device *dev);
123 
124 /*
125  * Driver data (common to all clients)
126  */
127 
128 static const struct i2c_device_id lm83_id[] = {
129 	{ "lm83", lm83 },
130 	{ "lm82", lm82 },
131 	{ }
132 };
133 MODULE_DEVICE_TABLE(i2c, lm83_id);
134 
135 static struct i2c_driver lm83_driver = {
136 	.class		= I2C_CLASS_HWMON,
137 	.driver = {
138 		.name	= "lm83",
139 	},
140 	.probe		= lm83_probe,
141 	.remove		= lm83_remove,
142 	.id_table	= lm83_id,
143 	.detect		= lm83_detect,
144 	.address_list	= normal_i2c,
145 };
146 
147 /*
148  * Client data (each client gets its own)
149  */
150 
151 struct lm83_data {
152 	struct device *hwmon_dev;
153 	struct mutex update_lock;
154 	char valid; /* zero until following fields are valid */
155 	unsigned long last_updated; /* in jiffies */
156 
157 	/* registers values */
158 	s8 temp[9];	/* 0..3: input 1-4,
159 			   4..7: high limit 1-4,
160 			   8   : critical limit */
161 	u16 alarms; /* bitvector, combined */
162 };
163 
164 /*
165  * Sysfs stuff
166  */
167 
168 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
169 			 char *buf)
170 {
171 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
172 	struct lm83_data *data = lm83_update_device(dev);
173 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
174 }
175 
176 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
177 			const char *buf, size_t count)
178 {
179 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
180 	struct i2c_client *client = to_i2c_client(dev);
181 	struct lm83_data *data = i2c_get_clientdata(client);
182 	long val;
183 	int nr = attr->index;
184 	int err;
185 
186 	err = kstrtol(buf, 10, &val);
187 	if (err < 0)
188 		return err;
189 
190 	mutex_lock(&data->update_lock);
191 	data->temp[nr] = TEMP_TO_REG(val);
192 	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
193 				  data->temp[nr]);
194 	mutex_unlock(&data->update_lock);
195 	return count;
196 }
197 
198 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
199 			   char *buf)
200 {
201 	struct lm83_data *data = lm83_update_device(dev);
202 	return sprintf(buf, "%d\n", data->alarms);
203 }
204 
205 static ssize_t show_alarm(struct device *dev, struct device_attribute
206 			  *devattr, char *buf)
207 {
208 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
209 	struct lm83_data *data = lm83_update_device(dev);
210 	int bitnr = attr->index;
211 
212 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
213 }
214 
215 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
216 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
217 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
218 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
219 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
220 	set_temp, 4);
221 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
222 	set_temp, 5);
223 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
224 	set_temp, 6);
225 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
226 	set_temp, 7);
227 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
228 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
229 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
230 	set_temp, 8);
231 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
232 
233 /* Individual alarm files */
234 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
235 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
236 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
237 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
238 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
239 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
240 static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
241 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
242 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
243 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
244 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
245 /* Raw alarm file for compatibility */
246 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
247 
248 static struct attribute *lm83_attributes[] = {
249 	&sensor_dev_attr_temp1_input.dev_attr.attr,
250 	&sensor_dev_attr_temp3_input.dev_attr.attr,
251 	&sensor_dev_attr_temp1_max.dev_attr.attr,
252 	&sensor_dev_attr_temp3_max.dev_attr.attr,
253 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
254 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
255 
256 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
257 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
258 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
259 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
260 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
261 	&dev_attr_alarms.attr,
262 	NULL
263 };
264 
265 static const struct attribute_group lm83_group = {
266 	.attrs = lm83_attributes,
267 };
268 
269 static struct attribute *lm83_attributes_opt[] = {
270 	&sensor_dev_attr_temp2_input.dev_attr.attr,
271 	&sensor_dev_attr_temp4_input.dev_attr.attr,
272 	&sensor_dev_attr_temp2_max.dev_attr.attr,
273 	&sensor_dev_attr_temp4_max.dev_attr.attr,
274 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
275 	&sensor_dev_attr_temp4_crit.dev_attr.attr,
276 
277 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
278 	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
279 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
280 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
281 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
282 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
283 	NULL
284 };
285 
286 static const struct attribute_group lm83_group_opt = {
287 	.attrs = lm83_attributes_opt,
288 };
289 
290 /*
291  * Real code
292  */
293 
294 /* Return 0 if detection is successful, -ENODEV otherwise */
295 static int lm83_detect(struct i2c_client *new_client,
296 		       struct i2c_board_info *info)
297 {
298 	struct i2c_adapter *adapter = new_client->adapter;
299 	const char *name;
300 	u8 man_id, chip_id;
301 
302 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
303 		return -ENODEV;
304 
305 	/* Detection */
306 	if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
307 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
308 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
309 		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
310 			new_client->addr);
311 		return -ENODEV;
312 	}
313 
314 	/* Identification */
315 	man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
316 	if (man_id != 0x01)	/* National Semiconductor */
317 		return -ENODEV;
318 
319 	chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
320 	switch (chip_id) {
321 	case 0x03:
322 		name = "lm83";
323 		break;
324 	case 0x01:
325 		name = "lm82";
326 		break;
327 	default:
328 		/* identification failed */
329 		dev_info(&adapter->dev,
330 			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
331 			 man_id, chip_id);
332 		return -ENODEV;
333 	}
334 
335 	strlcpy(info->type, name, I2C_NAME_SIZE);
336 
337 	return 0;
338 }
339 
340 static int lm83_probe(struct i2c_client *new_client,
341 		      const struct i2c_device_id *id)
342 {
343 	struct lm83_data *data;
344 	int err;
345 
346 	data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL);
347 	if (!data) {
348 		err = -ENOMEM;
349 		goto exit;
350 	}
351 
352 	i2c_set_clientdata(new_client, data);
353 	data->valid = 0;
354 	mutex_init(&data->update_lock);
355 
356 	/*
357 	 * Register sysfs hooks
358 	 * The LM82 can only monitor one external diode which is
359 	 * at the same register as the LM83 temp3 entry - so we
360 	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
361 	 */
362 
363 	err = sysfs_create_group(&new_client->dev.kobj, &lm83_group);
364 	if (err)
365 		goto exit_free;
366 
367 	if (id->driver_data == lm83) {
368 		err = sysfs_create_group(&new_client->dev.kobj,
369 					 &lm83_group_opt);
370 		if (err)
371 			goto exit_remove_files;
372 	}
373 
374 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
375 	if (IS_ERR(data->hwmon_dev)) {
376 		err = PTR_ERR(data->hwmon_dev);
377 		goto exit_remove_files;
378 	}
379 
380 	return 0;
381 
382 exit_remove_files:
383 	sysfs_remove_group(&new_client->dev.kobj, &lm83_group);
384 	sysfs_remove_group(&new_client->dev.kobj, &lm83_group_opt);
385 exit_free:
386 	kfree(data);
387 exit:
388 	return err;
389 }
390 
391 static int lm83_remove(struct i2c_client *client)
392 {
393 	struct lm83_data *data = i2c_get_clientdata(client);
394 
395 	hwmon_device_unregister(data->hwmon_dev);
396 	sysfs_remove_group(&client->dev.kobj, &lm83_group);
397 	sysfs_remove_group(&client->dev.kobj, &lm83_group_opt);
398 
399 	kfree(data);
400 	return 0;
401 }
402 
403 static struct lm83_data *lm83_update_device(struct device *dev)
404 {
405 	struct i2c_client *client = to_i2c_client(dev);
406 	struct lm83_data *data = i2c_get_clientdata(client);
407 
408 	mutex_lock(&data->update_lock);
409 
410 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
411 		int nr;
412 
413 		dev_dbg(&client->dev, "Updating lm83 data.\n");
414 		for (nr = 0; nr < 9; nr++) {
415 			data->temp[nr] =
416 			    i2c_smbus_read_byte_data(client,
417 			    LM83_REG_R_TEMP[nr]);
418 		}
419 		data->alarms =
420 		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
421 		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
422 		    << 8);
423 
424 		data->last_updated = jiffies;
425 		data->valid = 1;
426 	}
427 
428 	mutex_unlock(&data->update_lock);
429 
430 	return data;
431 }
432 
433 module_i2c_driver(lm83_driver);
434 
435 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
436 MODULE_DESCRIPTION("LM83 driver");
437 MODULE_LICENSE("GPL");
438