xref: /openbmc/linux/drivers/hwmon/lm83.c (revision d5cb9783536a41df9f9cba5b0a1d78047ed787f7)
1 /*
2  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
3  *          monitoring
4  * Copyright (C) 2003-2005  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  * This program is free software; you can redistribute it and/or modify
16  * it under the terms of the GNU General Public License as published by
17  * the Free Software Foundation; either version 2 of the License, or
18  * (at your option) any later version.
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; if not, write to the Free Software
27  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28  */
29 
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/slab.h>
33 #include <linux/jiffies.h>
34 #include <linux/i2c.h>
35 #include <linux/hwmon-sysfs.h>
36 #include <linux/hwmon.h>
37 #include <linux/err.h>
38 
39 /*
40  * Addresses to scan
41  * Address is selected using 2 three-level pins, resulting in 9 possible
42  * addresses.
43  */
44 
45 static unsigned short normal_i2c[] = { 0x18, 0x19, 0x1a,
46 					0x29, 0x2a, 0x2b,
47 					0x4c, 0x4d, 0x4e,
48 					I2C_CLIENT_END };
49 
50 /*
51  * Insmod parameters
52  */
53 
54 I2C_CLIENT_INSMOD_1(lm83);
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_attach_adapter(struct i2c_adapter *adapter);
118 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind);
119 static int lm83_detach_client(struct i2c_client *client);
120 static struct lm83_data *lm83_update_device(struct device *dev);
121 
122 /*
123  * Driver data (common to all clients)
124  */
125 
126 static struct i2c_driver lm83_driver = {
127 	.owner		= THIS_MODULE,
128 	.name		= "lm83",
129 	.id		= I2C_DRIVERID_LM83,
130 	.flags		= I2C_DF_NOTIFY,
131 	.attach_adapter	= lm83_attach_adapter,
132 	.detach_client	= lm83_detach_client,
133 };
134 
135 /*
136  * Client data (each client gets its own)
137  */
138 
139 struct lm83_data {
140 	struct i2c_client client;
141 	struct class_device *class_dev;
142 	struct semaphore update_lock;
143 	char valid; /* zero until following fields are valid */
144 	unsigned long last_updated; /* in jiffies */
145 
146 	/* registers values */
147 	s8 temp[9];	/* 0..3: input 1-4,
148 			   4..7: high limit 1-4,
149 			   8   : critical limit */
150 	u16 alarms; /* bitvector, combined */
151 };
152 
153 /*
154  * Sysfs stuff
155  */
156 
157 static ssize_t show_temp(struct device *dev, struct device_attribute *devattr,
158 			 char *buf)
159 {
160 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
161 	struct lm83_data *data = lm83_update_device(dev);
162 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
163 }
164 
165 static ssize_t set_temp(struct device *dev, struct device_attribute *devattr,
166 			const char *buf, size_t count)
167 {
168 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
169 	struct i2c_client *client = to_i2c_client(dev);
170 	struct lm83_data *data = i2c_get_clientdata(client);
171 	long val = simple_strtol(buf, NULL, 10);
172 	int nr = attr->index;
173 
174 	down(&data->update_lock);
175 	data->temp[nr] = TEMP_TO_REG(val);
176 	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
177 				  data->temp[nr]);
178 	up(&data->update_lock);
179 	return count;
180 }
181 
182 static ssize_t show_alarms(struct device *dev, struct device_attribute *dummy,
183 			   char *buf)
184 {
185 	struct lm83_data *data = lm83_update_device(dev);
186 	return sprintf(buf, "%d\n", data->alarms);
187 }
188 
189 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
190 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
191 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
192 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
193 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO, show_temp,
194 	set_temp, 4);
195 static SENSOR_DEVICE_ATTR(temp2_max, S_IWUSR | S_IRUGO, show_temp,
196 	set_temp, 5);
197 static SENSOR_DEVICE_ATTR(temp3_max, S_IWUSR | S_IRUGO, show_temp,
198 	set_temp, 6);
199 static SENSOR_DEVICE_ATTR(temp4_max, S_IWUSR | S_IRUGO, show_temp,
200 	set_temp, 7);
201 static SENSOR_DEVICE_ATTR(temp1_crit, S_IRUGO, show_temp, NULL, 8);
202 static SENSOR_DEVICE_ATTR(temp2_crit, S_IRUGO, show_temp, NULL, 8);
203 static SENSOR_DEVICE_ATTR(temp3_crit, S_IWUSR | S_IRUGO, show_temp,
204 	set_temp, 8);
205 static SENSOR_DEVICE_ATTR(temp4_crit, S_IRUGO, show_temp, NULL, 8);
206 static DEVICE_ATTR(alarms, S_IRUGO, show_alarms, NULL);
207 
208 /*
209  * Real code
210  */
211 
212 static int lm83_attach_adapter(struct i2c_adapter *adapter)
213 {
214 	if (!(adapter->class & I2C_CLASS_HWMON))
215 		return 0;
216 	return i2c_probe(adapter, &addr_data, lm83_detect);
217 }
218 
219 /*
220  * The following function does more than just detection. If detection
221  * succeeds, it also registers the new chip.
222  */
223 static int lm83_detect(struct i2c_adapter *adapter, int address, int kind)
224 {
225 	struct i2c_client *new_client;
226 	struct lm83_data *data;
227 	int err = 0;
228 	const char *name = "";
229 
230 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
231 		goto exit;
232 
233 	if (!(data = kzalloc(sizeof(struct lm83_data), GFP_KERNEL))) {
234 		err = -ENOMEM;
235 		goto exit;
236 	}
237 
238 	/* The common I2C client data is placed right after the
239 	 * LM83-specific data. */
240 	new_client = &data->client;
241 	i2c_set_clientdata(new_client, data);
242 	new_client->addr = address;
243 	new_client->adapter = adapter;
244 	new_client->driver = &lm83_driver;
245 	new_client->flags = 0;
246 
247 	/* Now we do the detection and identification. A negative kind
248 	 * means that the driver was loaded with no force parameter
249 	 * (default), so we must both detect and identify the chip
250 	 * (actually there is only one possible kind of chip for now, LM83).
251 	 * A zero kind means that the driver was loaded with the force
252 	 * parameter, the detection step shall be skipped. A positive kind
253 	 * means that the driver was loaded with the force parameter and a
254 	 * given kind of chip is requested, so both the detection and the
255 	 * identification steps are skipped. */
256 
257 	/* Default to an LM83 if forced */
258 	if (kind == 0)
259 		kind = lm83;
260 
261 	if (kind < 0) { /* detection */
262 		if (((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1)
263 		    & 0xA8) != 0x00) ||
264 		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2)
265 		    & 0x48) != 0x00) ||
266 		    ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG)
267 		    & 0x41) != 0x00)) {
268 			dev_dbg(&adapter->dev,
269 			    "LM83 detection failed at 0x%02x.\n", address);
270 			goto exit_free;
271 		}
272 	}
273 
274 	if (kind <= 0) { /* identification */
275 		u8 man_id, chip_id;
276 
277 		man_id = i2c_smbus_read_byte_data(new_client,
278 		    LM83_REG_R_MAN_ID);
279 		chip_id = i2c_smbus_read_byte_data(new_client,
280 		    LM83_REG_R_CHIP_ID);
281 
282 		if (man_id == 0x01) { /* National Semiconductor */
283 			if (chip_id == 0x03) {
284 				kind = lm83;
285 			}
286 		}
287 
288 		if (kind <= 0) { /* identification failed */
289 			dev_info(&adapter->dev,
290 			    "Unsupported chip (man_id=0x%02X, "
291 			    "chip_id=0x%02X).\n", man_id, chip_id);
292 			goto exit_free;
293 		}
294 	}
295 
296 	if (kind == lm83) {
297 		name = "lm83";
298 	}
299 
300 	/* We can fill in the remaining client fields */
301 	strlcpy(new_client->name, name, I2C_NAME_SIZE);
302 	data->valid = 0;
303 	init_MUTEX(&data->update_lock);
304 
305 	/* Tell the I2C layer a new client has arrived */
306 	if ((err = i2c_attach_client(new_client)))
307 		goto exit_free;
308 
309 	/*
310 	 * Initialize the LM83 chip
311 	 * (Nothing to do for this one.)
312 	 */
313 
314 	/* Register sysfs hooks */
315 	data->class_dev = hwmon_device_register(&new_client->dev);
316 	if (IS_ERR(data->class_dev)) {
317 		err = PTR_ERR(data->class_dev);
318 		goto exit_detach;
319 	}
320 
321 	device_create_file(&new_client->dev,
322 			   &sensor_dev_attr_temp1_input.dev_attr);
323 	device_create_file(&new_client->dev,
324 			   &sensor_dev_attr_temp2_input.dev_attr);
325 	device_create_file(&new_client->dev,
326 			   &sensor_dev_attr_temp3_input.dev_attr);
327 	device_create_file(&new_client->dev,
328 			   &sensor_dev_attr_temp4_input.dev_attr);
329 	device_create_file(&new_client->dev,
330 			   &sensor_dev_attr_temp1_max.dev_attr);
331 	device_create_file(&new_client->dev,
332 			   &sensor_dev_attr_temp2_max.dev_attr);
333 	device_create_file(&new_client->dev,
334 			   &sensor_dev_attr_temp3_max.dev_attr);
335 	device_create_file(&new_client->dev,
336 			   &sensor_dev_attr_temp4_max.dev_attr);
337 	device_create_file(&new_client->dev,
338 			   &sensor_dev_attr_temp1_crit.dev_attr);
339 	device_create_file(&new_client->dev,
340 			   &sensor_dev_attr_temp2_crit.dev_attr);
341 	device_create_file(&new_client->dev,
342 			   &sensor_dev_attr_temp3_crit.dev_attr);
343 	device_create_file(&new_client->dev,
344 			   &sensor_dev_attr_temp4_crit.dev_attr);
345 	device_create_file(&new_client->dev, &dev_attr_alarms);
346 
347 	return 0;
348 
349 exit_detach:
350 	i2c_detach_client(new_client);
351 exit_free:
352 	kfree(data);
353 exit:
354 	return err;
355 }
356 
357 static int lm83_detach_client(struct i2c_client *client)
358 {
359 	struct lm83_data *data = i2c_get_clientdata(client);
360 	int err;
361 
362 	hwmon_device_unregister(data->class_dev);
363 
364 	if ((err = i2c_detach_client(client)))
365 		return err;
366 
367 	kfree(data);
368 	return 0;
369 }
370 
371 static struct lm83_data *lm83_update_device(struct device *dev)
372 {
373 	struct i2c_client *client = to_i2c_client(dev);
374 	struct lm83_data *data = i2c_get_clientdata(client);
375 
376 	down(&data->update_lock);
377 
378 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
379 		int nr;
380 
381 		dev_dbg(&client->dev, "Updating lm83 data.\n");
382 		for (nr = 0; nr < 9; nr++) {
383 			data->temp[nr] =
384 			    i2c_smbus_read_byte_data(client,
385 			    LM83_REG_R_TEMP[nr]);
386 		}
387 		data->alarms =
388 		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
389 		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
390 		    << 8);
391 
392 		data->last_updated = jiffies;
393 		data->valid = 1;
394 	}
395 
396 	up(&data->update_lock);
397 
398 	return data;
399 }
400 
401 static int __init sensors_lm83_init(void)
402 {
403 	return i2c_add_driver(&lm83_driver);
404 }
405 
406 static void __exit sensors_lm83_exit(void)
407 {
408 	i2c_del_driver(&lm83_driver);
409 }
410 
411 MODULE_AUTHOR("Jean Delvare <khali@linux-fr.org>");
412 MODULE_DESCRIPTION("LM83 driver");
413 MODULE_LICENSE("GPL");
414 
415 module_init(sensors_lm83_init);
416 module_exit(sensors_lm83_exit);
417