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/bits.h>
22 #include <linux/err.h>
23 #include <linux/i2c.h>
24 #include <linux/init.h>
25 #include <linux/hwmon.h>
26 #include <linux/module.h>
27 #include <linux/regmap.h>
28 #include <linux/slab.h>
29
30 /*
31 * Addresses to scan
32 * Address is selected using 2 three-level pins, resulting in 9 possible
33 * addresses.
34 */
35
36 static const unsigned short normal_i2c[] = {
37 0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
38
39 enum chips { lm83, lm82 };
40
41 /*
42 * The LM83 registers
43 * Manufacturer ID is 0x01 for National Semiconductor.
44 */
45
46 #define LM83_REG_R_MAN_ID 0xFE
47 #define LM83_REG_R_CHIP_ID 0xFF
48 #define LM83_REG_R_CONFIG 0x03
49 #define LM83_REG_W_CONFIG 0x09
50 #define LM83_REG_R_STATUS1 0x02
51 #define LM83_REG_R_STATUS2 0x35
52 #define LM83_REG_R_LOCAL_TEMP 0x00
53 #define LM83_REG_R_LOCAL_HIGH 0x05
54 #define LM83_REG_W_LOCAL_HIGH 0x0B
55 #define LM83_REG_R_REMOTE1_TEMP 0x30
56 #define LM83_REG_R_REMOTE1_HIGH 0x38
57 #define LM83_REG_W_REMOTE1_HIGH 0x50
58 #define LM83_REG_R_REMOTE2_TEMP 0x01
59 #define LM83_REG_R_REMOTE2_HIGH 0x07
60 #define LM83_REG_W_REMOTE2_HIGH 0x0D
61 #define LM83_REG_R_REMOTE3_TEMP 0x31
62 #define LM83_REG_R_REMOTE3_HIGH 0x3A
63 #define LM83_REG_W_REMOTE3_HIGH 0x52
64 #define LM83_REG_R_TCRIT 0x42
65 #define LM83_REG_W_TCRIT 0x5A
66
67 static const u8 LM83_REG_TEMP[] = {
68 LM83_REG_R_LOCAL_TEMP,
69 LM83_REG_R_REMOTE1_TEMP,
70 LM83_REG_R_REMOTE2_TEMP,
71 LM83_REG_R_REMOTE3_TEMP,
72 };
73
74 static const u8 LM83_REG_MAX[] = {
75 LM83_REG_R_LOCAL_HIGH,
76 LM83_REG_R_REMOTE1_HIGH,
77 LM83_REG_R_REMOTE2_HIGH,
78 LM83_REG_R_REMOTE3_HIGH,
79 };
80
81 /* alarm and fault registers and bits, indexed by channel */
82 static const u8 LM83_ALARM_REG[] = {
83 LM83_REG_R_STATUS1, LM83_REG_R_STATUS2, LM83_REG_R_STATUS1, LM83_REG_R_STATUS2
84 };
85
86 static const u8 LM83_MAX_ALARM_BIT[] = {
87 BIT(6), BIT(7), BIT(4), BIT(4)
88 };
89
90 static const u8 LM83_CRIT_ALARM_BIT[] = {
91 BIT(0), BIT(0), BIT(1), BIT(1)
92 };
93
94 static const u8 LM83_FAULT_BIT[] = {
95 0, BIT(5), BIT(2), BIT(2)
96 };
97
98 /*
99 * Client data (each client gets its own)
100 */
101
102 struct lm83_data {
103 struct regmap *regmap;
104 enum chips type;
105 };
106
107 /* regmap code */
108
lm83_regmap_reg_read(void * context,unsigned int reg,unsigned int * val)109 static int lm83_regmap_reg_read(void *context, unsigned int reg, unsigned int *val)
110 {
111 struct i2c_client *client = context;
112 int ret;
113
114 ret = i2c_smbus_read_byte_data(client, reg);
115 if (ret < 0)
116 return ret;
117
118 *val = ret;
119 return 0;
120 }
121
122 /*
123 * The regmap write function maps read register addresses to write register
124 * addresses. This is necessary for regmap register caching to work.
125 * An alternative would be to clear the regmap cache whenever a register is
126 * written, but that would be much more expensive.
127 */
lm83_regmap_reg_write(void * context,unsigned int reg,unsigned int val)128 static int lm83_regmap_reg_write(void *context, unsigned int reg, unsigned int val)
129 {
130 struct i2c_client *client = context;
131
132 switch (reg) {
133 case LM83_REG_R_CONFIG:
134 case LM83_REG_R_LOCAL_HIGH:
135 case LM83_REG_R_REMOTE2_HIGH:
136 reg += 0x06;
137 break;
138 case LM83_REG_R_REMOTE1_HIGH:
139 case LM83_REG_R_REMOTE3_HIGH:
140 case LM83_REG_R_TCRIT:
141 reg += 0x18;
142 break;
143 default:
144 break;
145 }
146
147 return i2c_smbus_write_byte_data(client, reg, val);
148 }
149
lm83_regmap_is_volatile(struct device * dev,unsigned int reg)150 static bool lm83_regmap_is_volatile(struct device *dev, unsigned int reg)
151 {
152 switch (reg) {
153 case LM83_REG_R_LOCAL_TEMP:
154 case LM83_REG_R_REMOTE1_TEMP:
155 case LM83_REG_R_REMOTE2_TEMP:
156 case LM83_REG_R_REMOTE3_TEMP:
157 case LM83_REG_R_STATUS1:
158 case LM83_REG_R_STATUS2:
159 return true;
160 default:
161 return false;
162 }
163 }
164
165 static const struct regmap_config lm83_regmap_config = {
166 .reg_bits = 8,
167 .val_bits = 8,
168 .cache_type = REGCACHE_MAPLE,
169 .volatile_reg = lm83_regmap_is_volatile,
170 .reg_read = lm83_regmap_reg_read,
171 .reg_write = lm83_regmap_reg_write,
172 };
173
174 /* hwmon API */
175
lm83_temp_read(struct device * dev,u32 attr,int channel,long * val)176 static int lm83_temp_read(struct device *dev, u32 attr, int channel, long *val)
177 {
178 struct lm83_data *data = dev_get_drvdata(dev);
179 unsigned int regval;
180 int err;
181
182 switch (attr) {
183 case hwmon_temp_input:
184 err = regmap_read(data->regmap, LM83_REG_TEMP[channel], ®val);
185 if (err < 0)
186 return err;
187 *val = (s8)regval * 1000;
188 break;
189 case hwmon_temp_max:
190 err = regmap_read(data->regmap, LM83_REG_MAX[channel], ®val);
191 if (err < 0)
192 return err;
193 *val = (s8)regval * 1000;
194 break;
195 case hwmon_temp_crit:
196 err = regmap_read(data->regmap, LM83_REG_R_TCRIT, ®val);
197 if (err < 0)
198 return err;
199 *val = (s8)regval * 1000;
200 break;
201 case hwmon_temp_max_alarm:
202 err = regmap_read(data->regmap, LM83_ALARM_REG[channel], ®val);
203 if (err < 0)
204 return err;
205 *val = !!(regval & LM83_MAX_ALARM_BIT[channel]);
206 break;
207 case hwmon_temp_crit_alarm:
208 err = regmap_read(data->regmap, LM83_ALARM_REG[channel], ®val);
209 if (err < 0)
210 return err;
211 *val = !!(regval & LM83_CRIT_ALARM_BIT[channel]);
212 break;
213 case hwmon_temp_fault:
214 err = regmap_read(data->regmap, LM83_ALARM_REG[channel], ®val);
215 if (err < 0)
216 return err;
217 *val = !!(regval & LM83_FAULT_BIT[channel]);
218 break;
219 default:
220 return -EOPNOTSUPP;
221 }
222 return 0;
223 }
224
lm83_temp_write(struct device * dev,u32 attr,int channel,long val)225 static int lm83_temp_write(struct device *dev, u32 attr, int channel, long val)
226 {
227 struct lm83_data *data = dev_get_drvdata(dev);
228 unsigned int regval;
229 int err;
230
231 regval = DIV_ROUND_CLOSEST(clamp_val(val, -128000, 127000), 1000);
232
233 switch (attr) {
234 case hwmon_temp_max:
235 err = regmap_write(data->regmap, LM83_REG_MAX[channel], regval);
236 if (err < 0)
237 return err;
238 break;
239 case hwmon_temp_crit:
240 err = regmap_write(data->regmap, LM83_REG_R_TCRIT, regval);
241 if (err < 0)
242 return err;
243 break;
244 default:
245 return -EOPNOTSUPP;
246 }
247 return 0;
248 }
249
lm83_chip_read(struct device * dev,u32 attr,int channel,long * val)250 static int lm83_chip_read(struct device *dev, u32 attr, int channel, long *val)
251 {
252 struct lm83_data *data = dev_get_drvdata(dev);
253 unsigned int regval;
254 int err;
255
256 switch (attr) {
257 case hwmon_chip_alarms:
258 err = regmap_read(data->regmap, LM83_REG_R_STATUS1, ®val);
259 if (err < 0)
260 return err;
261 *val = regval;
262 err = regmap_read(data->regmap, LM83_REG_R_STATUS2, ®val);
263 if (err < 0)
264 return err;
265 *val |= regval << 8;
266 return 0;
267 default:
268 return -EOPNOTSUPP;
269 }
270
271 return 0;
272 }
273
lm83_read(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long * val)274 static int lm83_read(struct device *dev, enum hwmon_sensor_types type,
275 u32 attr, int channel, long *val)
276 {
277 switch (type) {
278 case hwmon_chip:
279 return lm83_chip_read(dev, attr, channel, val);
280 case hwmon_temp:
281 return lm83_temp_read(dev, attr, channel, val);
282 default:
283 return -EOPNOTSUPP;
284 }
285 }
286
lm83_write(struct device * dev,enum hwmon_sensor_types type,u32 attr,int channel,long val)287 static int lm83_write(struct device *dev, enum hwmon_sensor_types type,
288 u32 attr, int channel, long val)
289 {
290 switch (type) {
291 case hwmon_temp:
292 return lm83_temp_write(dev, attr, channel, val);
293 default:
294 return -EOPNOTSUPP;
295 }
296 }
297
lm83_is_visible(const void * _data,enum hwmon_sensor_types type,u32 attr,int channel)298 static umode_t lm83_is_visible(const void *_data, enum hwmon_sensor_types type,
299 u32 attr, int channel)
300 {
301 const struct lm83_data *data = _data;
302
303 /*
304 * LM82 only supports a single external channel, modeled as channel 2.
305 */
306 if (data->type == lm82 && (channel == 1 || channel == 3))
307 return 0;
308
309 switch (type) {
310 case hwmon_chip:
311 if (attr == hwmon_chip_alarms)
312 return 0444;
313 break;
314 case hwmon_temp:
315 switch (attr) {
316 case hwmon_temp_input:
317 case hwmon_temp_max_alarm:
318 case hwmon_temp_crit_alarm:
319 return 0444;
320 case hwmon_temp_fault:
321 if (channel)
322 return 0444;
323 break;
324 case hwmon_temp_max:
325 return 0644;
326 case hwmon_temp_crit:
327 if (channel == 2)
328 return 0644;
329 return 0444;
330 default:
331 break;
332 }
333 break;
334 default:
335 break;
336 }
337 return 0;
338 }
339
340 static const struct hwmon_channel_info * const lm83_info[] = {
341 HWMON_CHANNEL_INFO(chip, HWMON_C_ALARMS),
342 HWMON_CHANNEL_INFO(temp,
343 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
344 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
345 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
346 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
347 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
348 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT,
349 HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_CRIT |
350 HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM | HWMON_T_FAULT
351 ),
352 NULL
353 };
354
355 static const struct hwmon_ops lm83_hwmon_ops = {
356 .is_visible = lm83_is_visible,
357 .read = lm83_read,
358 .write = lm83_write,
359 };
360
361 static const struct hwmon_chip_info lm83_chip_info = {
362 .ops = &lm83_hwmon_ops,
363 .info = lm83_info,
364 };
365
366 /* Return 0 if detection is successful, -ENODEV otherwise */
lm83_detect(struct i2c_client * client,struct i2c_board_info * info)367 static int lm83_detect(struct i2c_client *client,
368 struct i2c_board_info *info)
369 {
370 struct i2c_adapter *adapter = client->adapter;
371 const char *name;
372 u8 man_id, chip_id;
373
374 if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
375 return -ENODEV;
376
377 /* Detection */
378 if ((i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS1) & 0xA8) ||
379 (i2c_smbus_read_byte_data(client, LM83_REG_R_STATUS2) & 0x48) ||
380 (i2c_smbus_read_byte_data(client, LM83_REG_R_CONFIG) & 0x41)) {
381 dev_dbg(&adapter->dev, "LM83 detection failed at 0x%02x\n",
382 client->addr);
383 return -ENODEV;
384 }
385
386 /* Identification */
387 man_id = i2c_smbus_read_byte_data(client, LM83_REG_R_MAN_ID);
388 if (man_id != 0x01) /* National Semiconductor */
389 return -ENODEV;
390
391 chip_id = i2c_smbus_read_byte_data(client, LM83_REG_R_CHIP_ID);
392 switch (chip_id) {
393 case 0x03:
394 /*
395 * According to the LM82 datasheet dated March 2013, recent
396 * revisions of LM82 have a die revision of 0x03. This was
397 * confirmed with a real chip. Further details in this revision
398 * of the LM82 datasheet strongly suggest that LM82 is just a
399 * repackaged LM83. It is therefore impossible to distinguish
400 * those chips from LM83, and they will be misdetected as LM83.
401 */
402 name = "lm83";
403 break;
404 case 0x01:
405 name = "lm82";
406 break;
407 default:
408 /* identification failed */
409 dev_dbg(&adapter->dev,
410 "Unsupported chip (man_id=0x%02X, chip_id=0x%02X)\n",
411 man_id, chip_id);
412 return -ENODEV;
413 }
414
415 strscpy(info->type, name, I2C_NAME_SIZE);
416
417 return 0;
418 }
419
lm83_probe(struct i2c_client * client)420 static int lm83_probe(struct i2c_client *client)
421 {
422 struct device *dev = &client->dev;
423 struct device *hwmon_dev;
424 struct lm83_data *data;
425
426 data = devm_kzalloc(dev, sizeof(struct lm83_data), GFP_KERNEL);
427 if (!data)
428 return -ENOMEM;
429
430 data->regmap = devm_regmap_init(dev, NULL, client, &lm83_regmap_config);
431 if (IS_ERR(data->regmap))
432 return PTR_ERR(data->regmap);
433
434 data->type = (uintptr_t)i2c_get_match_data(client);
435
436 hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
437 data, &lm83_chip_info, NULL);
438 return PTR_ERR_OR_ZERO(hwmon_dev);
439 }
440
441 /*
442 * Driver data (common to all clients)
443 */
444
445 static const struct i2c_device_id lm83_id[] = {
446 { "lm83", lm83 },
447 { "lm82", lm82 },
448 { }
449 };
450 MODULE_DEVICE_TABLE(i2c, lm83_id);
451
452 static struct i2c_driver lm83_driver = {
453 .class = I2C_CLASS_HWMON,
454 .driver = {
455 .name = "lm83",
456 },
457 .probe = lm83_probe,
458 .id_table = lm83_id,
459 .detect = lm83_detect,
460 .address_list = normal_i2c,
461 };
462
463 module_i2c_driver(lm83_driver);
464
465 MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
466 MODULE_DESCRIPTION("LM83 driver");
467 MODULE_LICENSE("GPL");
468