xref: /openbmc/linux/drivers/hwmon/lm83.c (revision 643d1f7f)
1 /*
2  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
3  *          monitoring
4  * Copyright (C) 2003-2006  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 unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
52 					0x29, 0x2a, 0x2b,
53 					0x4c, 0x4d, 0x4e,
54 					I2C_CLIENT_END };
55 
56 /*
57  * Insmod parameters
58  */
59 
60 I2C_CLIENT_INSMOD_2(lm83, lm82);
61 
62 /*
63  * The LM83 registers
64  * Manufacturer ID is 0x01 for National Semiconductor.
65  */
66 
67 #define LM83_REG_R_MAN_ID		0xFE
68 #define LM83_REG_R_CHIP_ID		0xFF
69 #define LM83_REG_R_CONFIG		0x03
70 #define LM83_REG_W_CONFIG		0x09
71 #define LM83_REG_R_STATUS1		0x02
72 #define LM83_REG_R_STATUS2		0x35
73 #define LM83_REG_R_LOCAL_TEMP		0x00
74 #define LM83_REG_R_LOCAL_HIGH		0x05
75 #define LM83_REG_W_LOCAL_HIGH		0x0B
76 #define LM83_REG_R_REMOTE1_TEMP		0x30
77 #define LM83_REG_R_REMOTE1_HIGH		0x38
78 #define LM83_REG_W_REMOTE1_HIGH		0x50
79 #define LM83_REG_R_REMOTE2_TEMP		0x01
80 #define LM83_REG_R_REMOTE2_HIGH		0x07
81 #define LM83_REG_W_REMOTE2_HIGH		0x0D
82 #define LM83_REG_R_REMOTE3_TEMP		0x31
83 #define LM83_REG_R_REMOTE3_HIGH		0x3A
84 #define LM83_REG_W_REMOTE3_HIGH		0x52
85 #define LM83_REG_R_TCRIT		0x42
86 #define LM83_REG_W_TCRIT		0x5A
87 
88 /*
89  * Conversions and various macros
90  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
91  */
92 
93 #define TEMP_FROM_REG(val)	((val) * 1000)
94 #define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
95 				 (val) >= 127000 ? 127 : \
96 				 (val) < 0 ? ((val) - 500) / 1000 : \
97 				 ((val) + 500) / 1000)
98 
99 static const u8 LM83_REG_R_TEMP[] = {
100 	LM83_REG_R_LOCAL_TEMP,
101 	LM83_REG_R_REMOTE1_TEMP,
102 	LM83_REG_R_REMOTE2_TEMP,
103 	LM83_REG_R_REMOTE3_TEMP,
104 	LM83_REG_R_LOCAL_HIGH,
105 	LM83_REG_R_REMOTE1_HIGH,
106 	LM83_REG_R_REMOTE2_HIGH,
107 	LM83_REG_R_REMOTE3_HIGH,
108 	LM83_REG_R_TCRIT,
109 };
110 
111 static const u8 LM83_REG_W_HIGH[] = {
112 	LM83_REG_W_LOCAL_HIGH,
113 	LM83_REG_W_REMOTE1_HIGH,
114 	LM83_REG_W_REMOTE2_HIGH,
115 	LM83_REG_W_REMOTE3_HIGH,
116 	LM83_REG_W_TCRIT,
117 };
118 
119 /*
120  * Functions declaration
121  */
122 
123 static int lm83_attach_adapter(struct i2c_adapter *adapter);
124 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
125 static int lm83_detach_client(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 struct i2c_driver lm83_driver = {
133 	.driver = {
134 		.name	= "lm83",
135 	},
136 	.id		= I2C_DRIVERID_LM83,
137 	.attach_adapter	= lm83_attach_adapter,
138 	.detach_client	= lm83_detach_client,
139 };
140 
141 /*
142  * Client data (each client gets its own)
143  */
144 
145 struct lm83_data {
146 	struct i2c_client client;
147 	struct device *hwmon_dev;
148 	struct mutex update_lock;
149 	char valid; /* zero until following fields are valid */
150 	unsigned long last_updated; /* in jiffies */
151 
152 	/* registers values */
153 	s8 temp[9];	/* 0..3: input 1-4,
154 			   4..7: high limit 1-4,
155 			   8   : critical limit */
156 	u16 alarms; /* bitvector, combined */
157 };
158 
159 /*
160  * Sysfs stuff
161  */
162 
163 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
164 			 char *buf)
165 {
166 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
167 	struct lm83_data *data = lm83_update_device(dev);
168 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
169 }
170 
171 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
172 			const char *buf, size_t count)
173 {
174 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
175 	struct i2c_client *client = to_i2c_client(dev);
176 	struct lm83_data *data = i2c_get_clientdata(client);
177 	long val = simple_strtol(buf, NULL, 10);
178 	int nr = attr->index;
179 
180 	mutex_lock(&data->update_lock);
181 	data->temp[nr] = TEMP_TO_REG(val);
182 	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
183 				  data->temp[nr]);
184 	mutex_unlock(&data->update_lock);
185 	return count;
186 }
187 
188 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
189 			   char *buf)
190 {
191 	struct lm83_data *data = lm83_update_device(dev);
192 	return sprintf(buf, "%d\n", data->alarms);
193 }
194 
195 static ssize_t show_alarm(struct device *dev, struct device_attribute
196 			  *devattr, char *buf)
197 {
198 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
199 	struct lm83_data *data = lm83_update_device(dev);
200 	int bitnr = attr->index;
201 
202 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
203 }
204 
205 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
206 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
207 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
208 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
209 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
210 	set_temp, 4);
211 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
212 	set_temp, 5);
213 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
214 	set_temp, 6);
215 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
216 	set_temp, 7);
217 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
218 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
219 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
220 	set_temp, 8);
221 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
222 
223 /* Individual alarm files */
224 static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL, 0);
225 static SENSOR_DEVICE_ATTR(temp3_crit_alarm, S_IRUGO, show_alarm, NULL, 1);
226 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_alarm, NULL, 2);
227 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
228 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 6);
229 static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL, 8);
230 static SENSOR_DEVICE_ATTR(temp4_crit_alarm, S_IRUGO, show_alarm, NULL, 9);
231 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_alarm, NULL, 10);
232 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 12);
233 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL, 13);
234 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 15);
235 /* Raw alarm file for compatibility */
236 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
237 
238 static struct attribute *lm83_attributes[] = {
239 	&sensor_dev_attr_temp1_input.dev_attr.attr,
240 	&sensor_dev_attr_temp3_input.dev_attr.attr,
241 	&sensor_dev_attr_temp1_max.dev_attr.attr,
242 	&sensor_dev_attr_temp3_max.dev_attr.attr,
243 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
244 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
245 
246 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
247 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
248 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
249 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
250 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
251 	&dev_attr_alarms.attr,
252 	NULL
253 };
254 
255 static const struct attribute_group lm83_group = {
256 	.attrs = lm83_attributes,
257 };
258 
259 static struct attribute *lm83_attributes_opt[] = {
260 	&sensor_dev_attr_temp2_input.dev_attr.attr,
261 	&sensor_dev_attr_temp4_input.dev_attr.attr,
262 	&sensor_dev_attr_temp2_max.dev_attr.attr,
263 	&sensor_dev_attr_temp4_max.dev_attr.attr,
264 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
265 	&sensor_dev_attr_temp4_crit.dev_attr.attr,
266 
267 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
268 	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
269 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
270 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
271 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
272 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
273 	NULL
274 };
275 
276 static const struct attribute_group lm83_group_opt = {
277 	.attrs = lm83_attributes_opt,
278 };
279 
280 /*
281  * Real code
282  */
283 
284 static int lm83_attach_adapter(struct i2c_adapter *adapter)
285 {
286 	if (!(adapter->class & I2C_CLASS_HWMON))
287 		return 0;
288 	return i2c_probe(adapter, &addr_data, lm83_detect);
289 }
290 
291 /*
292  * The following function does more than just detection. If detection
293  * succeeds, it also registers the new chip.
294  */
295 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
296 {
297 	struct i2c_client *new_client;
298 	struct lm83_data *data;
299 	int err = 0;
300 	const char *name = "";
301 
302 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
303 		goto exit;
304 
305 	if (!(data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
306 		err = -ENOMEM;
307 		goto exit;
308 	}
309 
310 	/* The common I2C client data is placed right after the
311 	 * LM83-specific data. */
312 	new_client = &data->client;
313 	i2c_set_clientdata(new_client, data);
314 	new_client->addr = address;
315 	new_client->adapter = adapter;
316 	new_client->driver = &lm83_driver;
317 	new_client->flags = 0;
318 
319 	/* Now we do the detection and identification. A negative kind
320 	 * means that the driver was loaded with no force parameter
321 	 * (default), so we must both detect and identify the chip
322 	 * (actually there is only one possible kind of chip for now, LM83).
323 	 * A zero kind means that the driver was loaded with the force
324 	 * parameter, the detection step shall be skipped. A positive kind
325 	 * means that the driver was loaded with the force parameter and a
326 	 * given kind of chip is requested, so both the detection and the
327 	 * identification steps are skipped. */
328 
329 	/* Default to an LM83 if forced */
330 	if (kind == 0)
331 		kind = lm83;
332 
333 	if (kind < 0) { /* detection */
334 		if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
335 		    & 0xA8) != 0x00) ||
336 		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
337 		    & 0x48) != 0x00) ||
338 		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
339 		    & 0x41) != 0x00)) {
340 			dev_dbg(&adapter->dev,
341 			    "LM83 detection failed at 0x%02x.\n", address);
342 			goto exit_free;
343 		}
344 	}
345 
346 	if (kind <= 0) { /* identification */
347 		u8 man_id, chip_id;
348 
349 		man_id = i2c_smbus_read_byte_data(new_client,
350 		    LM83_REG_R_MAN_ID);
351 		chip_id = i2c_smbus_read_byte_data(new_client,
352 		    LM83_REG_R_CHIP_ID);
353 
354 		if (man_id == 0x01) { /* National Semiconductor */
355 			if (chip_id == 0x03) {
356 				kind = lm83;
357 			} else
358 			if (chip_id == 0x01) {
359 				kind = lm82;
360 			}
361 		}
362 
363 		if (kind <= 0) { /* identification failed */
364 			dev_info(&adapter->dev,
365 			    "Unsupported chip (man_id=0x%02X, "
366 			    "chip_id=0x%02X).\n", man_id, chip_id);
367 			goto exit_free;
368 		}
369 	}
370 
371 	if (kind == lm83) {
372 		name = "lm83";
373 	} else
374 	if (kind == lm82) {
375 		name = "lm82";
376 	}
377 
378 	/* We can fill in the remaining client fields */
379 	strlcpy(new_client->name, name, I2C_NAME_SIZE);
380 	data->valid = 0;
381 	mutex_init(&data->update_lock);
382 
383 	/* Tell the I2C layer a new client has arrived */
384 	if ((err = i2c_attach_client(new_client)))
385 		goto exit_free;
386 
387 	/*
388 	 * Register sysfs hooks
389 	 * The LM82 can only monitor one external diode which is
390 	 * at the same register as the LM83 temp3 entry - so we
391 	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
392 	 */
393 
394 	if ((err = sysfs_create_group(&new_client->dev.kobj, &lm83_group)))
395 		goto exit_detach;
396 
397 	if (kind == lm83) {
398 		if ((err = sysfs_create_group(&new_client->dev.kobj,
399 					      &lm83_group_opt)))
400 			goto exit_remove_files;
401 	}
402 
403 	data->hwmon_dev = hwmon_device_register(&new_client->dev);
404 	if (IS_ERR(data->hwmon_dev)) {
405 		err = PTR_ERR(data->hwmon_dev);
406 		goto exit_remove_files;
407 	}
408 
409 	return 0;
410 
411 exit_remove_files:
412 	sysfs_remove_group(&new_client->dev.kobj, &lm83_group);
413 	sysfs_remove_group(&new_client->dev.kobj, &lm83_group_opt);
414 exit_detach:
415 	i2c_detach_client(new_client);
416 exit_free:
417 	kfree(data);
418 exit:
419 	return err;
420 }
421 
422 static int lm83_detach_client(struct i2c_client *client)
423 {
424 	struct lm83_data *data = i2c_get_clientdata(client);
425 	int err;
426 
427 	hwmon_device_unregister(data->hwmon_dev);
428 	sysfs_remove_group(&client->dev.kobj, &lm83_group);
429 	sysfs_remove_group(&client->dev.kobj, &lm83_group_opt);
430 
431 	if ((err = i2c_detach_client(client)))
432 		return err;
433 
434 	kfree(data);
435 	return 0;
436 }
437 
438 static struct lm83_data *lm83_update_device(struct device *dev)
439 {
440 	struct i2c_client *client = to_i2c_client(dev);
441 	struct lm83_data *data = i2c_get_clientdata(client);
442 
443 	mutex_lock(&data->update_lock);
444 
445 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
446 		int nr;
447 
448 		dev_dbg(&client->dev, "Updating lm83 data.\n");
449 		for (nr = 0; nr < 9; nr++) {
450 			data->temp[nr] =
451 			    i2c_smbus_read_byte_data(client,
452 			    LM83_REG_R_TEMP[nr]);
453 		}
454 		data->alarms =
455 		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
456 		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
457 		    << 8);
458 
459 		data->last_updated = jiffies;
460 		data->valid = 1;
461 	}
462 
463 	mutex_unlock(&data->update_lock);
464 
465 	return data;
466 }
467 
468 static int __init sensors_lm83_init(void)
469 {
470 	return i2c_add_driver(&lm83_driver);
471 }
472 
473 static void __exit sensors_lm83_exit(void)
474 {
475 	i2c_del_driver(&lm83_driver);
476 }
477 
478 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
479 MODULE_DESCRIPTION("LM83 driver");
480 MODULE_LICENSE("GPL");
481 
482 module_init(sensors_lm83_init);
483 module_exit(sensors_lm83_exit);
484