xref: /openbmc/linux/drivers/hwmon/lm83.c (revision b737eecd)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * lm83.c - Part of lm_sensors, Linux kernel modules for hardware
4  *          monitoring
5  * Copyright (C) 2003-2009  Jean Delvare <jdelvare@suse.de>
6  *
7  * Heavily inspired from the lm78, lm75 and adm1021 drivers. The LM83 is
8  * a sensor chip made by National Semiconductor. It reports up to four
9  * temperatures (its own plus up to three external ones) with a 1 deg
10  * resolution and a 3-4 deg accuracy. Complete datasheet can be obtained
11  * from National's website at:
12  *   http://www.national.com/pf/LM/LM83.html
13  * Since the datasheet omits to give the chip stepping code, I give it
14  * here: 0x03 (at register 0xff).
15  *
16  * Also supports the LM82 temp sensor, which is basically a stripped down
17  * model of the LM83.  Datasheet is here:
18  * http://www.national.com/pf/LM/LM82.html
19  */
20 
21 #include <linux/module.h>
22 #include <linux/init.h>
23 #include <linux/slab.h>
24 #include <linux/jiffies.h>
25 #include <linux/i2c.h>
26 #include <linux/hwmon-sysfs.h>
27 #include <linux/hwmon.h>
28 #include <linux/err.h>
29 #include <linux/mutex.h>
30 #include <linux/sysfs.h>
31 
32 /*
33  * Addresses to scan
34  * Address is selected using 2 three-level pins, resulting in 9 possible
35  * addresses.
36  */
37 
38 static const unsigned short normal_i2c[] = {
39 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
40 
41 enum chips { lm83, lm82 };
42 
43 /*
44  * The LM83 registers
45  * Manufacturer ID is 0x01 for National Semiconductor.
46  */
47 
48 #define LM83_REG_R_MAN_ID		0xFE
49 #define LM83_REG_R_CHIP_ID		0xFF
50 #define LM83_REG_R_CONFIG		0x03
51 #define LM83_REG_W_CONFIG		0x09
52 #define LM83_REG_R_STATUS1		0x02
53 #define LM83_REG_R_STATUS2		0x35
54 #define LM83_REG_R_LOCAL_TEMP		0x00
55 #define LM83_REG_R_LOCAL_HIGH		0x05
56 #define LM83_REG_W_LOCAL_HIGH		0x0B
57 #define LM83_REG_R_REMOTE1_TEMP		0x30
58 #define LM83_REG_R_REMOTE1_HIGH		0x38
59 #define LM83_REG_W_REMOTE1_HIGH		0x50
60 #define LM83_REG_R_REMOTE2_TEMP		0x01
61 #define LM83_REG_R_REMOTE2_HIGH		0x07
62 #define LM83_REG_W_REMOTE2_HIGH		0x0D
63 #define LM83_REG_R_REMOTE3_TEMP		0x31
64 #define LM83_REG_R_REMOTE3_HIGH		0x3A
65 #define LM83_REG_W_REMOTE3_HIGH		0x52
66 #define LM83_REG_R_TCRIT		0x42
67 #define LM83_REG_W_TCRIT		0x5A
68 
69 /*
70  * Conversions and various macros
71  * The LM83 uses signed 8-bit values with LSB = 1 degree Celsius.
72  */
73 
74 #define TEMP_FROM_REG(val)	((val) * 1000)
75 #define TEMP_TO_REG(val)	((val) <= -128000 ? -128 : \
76 				 (val) >= 127000 ? 127 : \
77 				 (val) < 0 ? ((val) - 500) / 1000 : \
78 				 ((val) + 500) / 1000)
79 
80 static const u8 LM83_REG_R_TEMP[] = {
81 	LM83_REG_R_LOCAL_TEMP,
82 	LM83_REG_R_REMOTE1_TEMP,
83 	LM83_REG_R_REMOTE2_TEMP,
84 	LM83_REG_R_REMOTE3_TEMP,
85 	LM83_REG_R_LOCAL_HIGH,
86 	LM83_REG_R_REMOTE1_HIGH,
87 	LM83_REG_R_REMOTE2_HIGH,
88 	LM83_REG_R_REMOTE3_HIGH,
89 	LM83_REG_R_TCRIT,
90 };
91 
92 static const u8 LM83_REG_W_HIGH[] = {
93 	LM83_REG_W_LOCAL_HIGH,
94 	LM83_REG_W_REMOTE1_HIGH,
95 	LM83_REG_W_REMOTE2_HIGH,
96 	LM83_REG_W_REMOTE3_HIGH,
97 	LM83_REG_W_TCRIT,
98 };
99 
100 /*
101  * Client data (each client gets its own)
102  */
103 
104 struct lm83_data {
105 	struct i2c_client *client;
106 	const struct attribute_group *groups[3];
107 	struct mutex update_lock;
108 	char valid; /* zero until following fields are valid */
109 	unsigned long last_updated; /* in jiffies */
110 
111 	/* registers values */
112 	s8 temp[9];	/* 0..3: input 1-4,
113 			   4..7: high limit 1-4,
114 			   8   : critical limit */
115 	u16 alarms; /* bitvector, combined */
116 };
117 
118 static struct lm83_data *lm83_update_device(struct device *dev)
119 {
120 	struct lm83_data *data = dev_get_drvdata(dev);
121 	struct i2c_client *client = data->client;
122 
123 	mutex_lock(&data->update_lock);
124 
125 	if (time_after(jiffies, data->last_updated + HZ * 2) || !data->valid) {
126 		int nr;
127 
128 		dev_dbg(&client->dev, "Updating lm83 data.\n");
129 		for (nr = 0; nr < 9; nr++) {
130 			data->temp[nr] =
131 			    i2c_smbus_read_byte_data(client,
132 			    LM83_REG_R_TEMP[nr]);
133 		}
134 		data->alarms =
135 		    i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1)
136 		    + (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2)
137 		    << 8);
138 
139 		data->last_updated = jiffies;
140 		data->valid = 1;
141 	}
142 
143 	mutex_unlock(&data->update_lock);
144 
145 	return data;
146 }
147 
148 /*
149  * Sysfs stuff
150  */
151 
152 static ssize_t temp_show(struct device *dev, struct device_attribute *devattr,
153 			 char *buf)
154 {
155 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
156 	struct lm83_data *data = lm83_update_device(dev);
157 	return sprintf(buf, "%d\n", TEMP_FROM_REG(data->temp[attr->index]));
158 }
159 
160 static ssize_t temp_store(struct device *dev,
161 			  struct device_attribute *devattr, const char *buf,
162 			  size_t count)
163 {
164 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
165 	struct lm83_data *data = dev_get_drvdata(dev);
166 	struct i2c_client *client = data->client;
167 	long val;
168 	int nr = attr->index;
169 	int err;
170 
171 	err = kstrtol(buf, 10, &val);
172 	if (err < 0)
173 		return err;
174 
175 	mutex_lock(&data->update_lock);
176 	data->temp[nr] = TEMP_TO_REG(val);
177 	i2c_smbus_write_byte_data(client, LM83_REG_W_HIGH[nr - 4],
178 				  data->temp[nr]);
179 	mutex_unlock(&data->update_lock);
180 	return count;
181 }
182 
183 static ssize_t alarms_show(struct device *dev, struct device_attribute *dummy,
184 			   char *buf)
185 {
186 	struct lm83_data *data = lm83_update_device(dev);
187 	return sprintf(buf, "%d\n", data->alarms);
188 }
189 
190 static ssize_t alarm_show(struct device *dev,
191 			  struct device_attribute *devattr, char *buf)
192 {
193 	struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
194 	struct lm83_data *data = lm83_update_device(dev);
195 	int bitnr = attr->index;
196 
197 	return sprintf(buf, "%d\n", (data->alarms >> bitnr) & 1);
198 }
199 
200 static SENSOR_DEVICE_ATTR_RO(temp1_input, temp, 0);
201 static SENSOR_DEVICE_ATTR_RO(temp2_input, temp, 1);
202 static SENSOR_DEVICE_ATTR_RO(temp3_input, temp, 2);
203 static SENSOR_DEVICE_ATTR_RO(temp4_input, temp, 3);
204 static SENSOR_DEVICE_ATTR_RW(temp1_max, temp, 4);
205 static SENSOR_DEVICE_ATTR_RW(temp2_max, temp, 5);
206 static SENSOR_DEVICE_ATTR_RW(temp3_max, temp, 6);
207 static SENSOR_DEVICE_ATTR_RW(temp4_max, temp, 7);
208 static SENSOR_DEVICE_ATTR_RO(temp1_crit, temp, 8);
209 static SENSOR_DEVICE_ATTR_RO(temp2_crit, temp, 8);
210 static SENSOR_DEVICE_ATTR_RW(temp3_crit, temp, 8);
211 static SENSOR_DEVICE_ATTR_RO(temp4_crit, temp, 8);
212 
213 /* Individual alarm files */
214 static SENSOR_DEVICE_ATTR_RO(temp1_crit_alarm, alarm, 0);
215 static SENSOR_DEVICE_ATTR_RO(temp3_crit_alarm, alarm, 1);
216 static SENSOR_DEVICE_ATTR_RO(temp3_fault, alarm, 2);
217 static SENSOR_DEVICE_ATTR_RO(temp3_max_alarm, alarm, 4);
218 static SENSOR_DEVICE_ATTR_RO(temp1_max_alarm, alarm, 6);
219 static SENSOR_DEVICE_ATTR_RO(temp2_crit_alarm, alarm, 8);
220 static SENSOR_DEVICE_ATTR_RO(temp4_crit_alarm, alarm, 9);
221 static SENSOR_DEVICE_ATTR_RO(temp4_fault, alarm, 10);
222 static SENSOR_DEVICE_ATTR_RO(temp4_max_alarm, alarm, 12);
223 static SENSOR_DEVICE_ATTR_RO(temp2_fault, alarm, 13);
224 static SENSOR_DEVICE_ATTR_RO(temp2_max_alarm, alarm, 15);
225 /* Raw alarm file for compatibility */
226 static DEVICE_ATTR_RO(alarms);
227 
228 static struct attribute *lm83_attributes[] = {
229 	&sensor_dev_attr_temp1_input.dev_attr.attr,
230 	&sensor_dev_attr_temp3_input.dev_attr.attr,
231 	&sensor_dev_attr_temp1_max.dev_attr.attr,
232 	&sensor_dev_attr_temp3_max.dev_attr.attr,
233 	&sensor_dev_attr_temp1_crit.dev_attr.attr,
234 	&sensor_dev_attr_temp3_crit.dev_attr.attr,
235 
236 	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
237 	&sensor_dev_attr_temp3_crit_alarm.dev_attr.attr,
238 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
239 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
240 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
241 	&dev_attr_alarms.attr,
242 	NULL
243 };
244 
245 static const struct attribute_group lm83_group = {
246 	.attrs = lm83_attributes,
247 };
248 
249 static struct attribute *lm83_attributes_opt[] = {
250 	&sensor_dev_attr_temp2_input.dev_attr.attr,
251 	&sensor_dev_attr_temp4_input.dev_attr.attr,
252 	&sensor_dev_attr_temp2_max.dev_attr.attr,
253 	&sensor_dev_attr_temp4_max.dev_attr.attr,
254 	&sensor_dev_attr_temp2_crit.dev_attr.attr,
255 	&sensor_dev_attr_temp4_crit.dev_attr.attr,
256 
257 	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
258 	&sensor_dev_attr_temp4_crit_alarm.dev_attr.attr,
259 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
260 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
261 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
262 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
263 	NULL
264 };
265 
266 static const struct attribute_group lm83_group_opt = {
267 	.attrs = lm83_attributes_opt,
268 };
269 
270 /*
271  * Real code
272  */
273 
274 /* Return 0 if detection is successful, -ENODEV otherwise */
275 static int lm83_detect(struct i2c_client *new_client,
276 		       struct i2c_board_info *info)
277 {
278 	struct i2c_adapter *adapter = new_client->adapter;
279 	const char *name;
280 	u8 man_id, chip_id;
281 
282 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
283 		return -ENODEV;
284 
285 	/* Detection */
286 	if ((i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS1) & 0xA8) ||
287 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_STATUS2) & 0x48) ||
288 	    (i2c_smbus_read_byte_data(new_client, LM83_REG_R_CONFIG) & 0x41)) {
289 		dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
290 			new_client->addr);
291 		return -ENODEV;
292 	}
293 
294 	/* Identification */
295 	man_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_MAN_ID);
296 	if (man_id != 0x01)	/* National Semiconductor */
297 		return -ENODEV;
298 
299 	chip_id = i2c_smbus_read_byte_data(new_client, LM83_REG_R_CHIP_ID);
300 	switch (chip_id) {
301 	case 0x03:
302 		name = "lm83";
303 		break;
304 	case 0x01:
305 		name = "lm82";
306 		break;
307 	default:
308 		/* identification failed */
309 		dev_info(&adapter->dev,
310 			 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
311 			 man_id, chip_id);
312 		return -ENODEV;
313 	}
314 
315 	strlcpy(info->type, name, I2C_NAME_SIZE);
316 
317 	return 0;
318 }
319 
320 static const struct i2c_device_id lm83_id[];
321 
322 static int lm83_probe(struct i2c_client *new_client)
323 {
324 	struct device *hwmon_dev;
325 	struct lm83_data *data;
326 
327 	data = devm_kzalloc(&new_client->dev, sizeof(struct lm83_data),
328 			    GFP_KERNEL);
329 	if (!data)
330 		return -ENOMEM;
331 
332 	data->client = new_client;
333 	mutex_init(&data->update_lock);
334 
335 	/*
336 	 * Register sysfs hooks
337 	 * The LM82 can only monitor one external diode which is
338 	 * at the same register as the LM83 temp3 entry - so we
339 	 * declare 1 and 3 common, and then 2 and 4 only for the LM83.
340 	 */
341 	data->groups[0] = &lm83_group;
342 	if (i2c_match_id(lm83_id, new_client)->driver_data == lm83)
343 		data->groups[1] = &lm83_group_opt;
344 
345 	hwmon_dev = devm_hwmon_device_register_with_groups(&new_client->dev,
346 							   new_client->name,
347 							   data, data->groups);
348 	return PTR_ERR_OR_ZERO(hwmon_dev);
349 }
350 
351 /*
352  * Driver data (common to all clients)
353  */
354 
355 static const struct i2c_device_id lm83_id[] = {
356 	{ "lm83", lm83 },
357 	{ "lm82", lm82 },
358 	{ }
359 };
360 MODULE_DEVICE_TABLE(i2c, lm83_id);
361 
362 static struct i2c_driver lm83_driver = {
363 	.class		= I2C_CLASS_HWMON,
364 	.driver = {
365 		.name	= "lm83",
366 	},
367 	.probe_new	= lm83_probe,
368 	.id_table	= lm83_id,
369 	.detect		= lm83_detect,
370 	.address_list	= normal_i2c,
371 };
372 
373 module_i2c_driver(lm83_driver);
374 
375 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
376 MODULE_DESCRIPTION("LM83 driver");
377 MODULE_LICENSE("GPL");
378