xref: /openbmc/linux/drivers/hwmon/lm83.c (revision 1975d167)
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_RBTREE,
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], &regval);
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], &regval);
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, &regval);
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], &regval);
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], &regval);
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], &regval);
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, &regval);
259 		if (err < 0)
260 			return err;
261 		*val = regval;
262 		err = regmap_read(data->regmap, LM83_REG_R_STATUS2, &regval);
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 
420 static const struct i2c_device_id lm83_id[] = {
421 	{ "lm83", lm83 },
422 	{ "lm82", lm82 },
423 	{ }
424 };
425 MODULE_DEVICE_TABLE(i2c, lm83_id);
426 
lm83_probe(struct i2c_client * client)427 static int lm83_probe(struct i2c_client *client)
428 {
429 	struct device *dev = &client->dev;
430 	struct device *hwmon_dev;
431 	struct lm83_data *data;
432 
433 	data = devm_kzalloc(dev, sizeof(struct lm83_data), GFP_KERNEL);
434 	if (!data)
435 		return -ENOMEM;
436 
437 	data->regmap = devm_regmap_init(dev, NULL, client, &lm83_regmap_config);
438 	if (IS_ERR(data->regmap))
439 		return PTR_ERR(data->regmap);
440 
441 	data->type = i2c_match_id(lm83_id, client)->driver_data;
442 
443 	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
444 							 data, &lm83_chip_info, NULL);
445 	return PTR_ERR_OR_ZERO(hwmon_dev);
446 }
447 
448 /*
449  * Driver data (common to all clients)
450  */
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