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
36static const unsigned short normal_i2c[] = {
37	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
38
39enum 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
67static 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
74static 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 */
82static const u8 LM83_ALARM_REG[] = {
83	LM83_REG_R_STATUS1, LM83_REG_R_STATUS2, LM83_REG_R_STATUS1, LM83_REG_R_STATUS2
84};
85
86static const u8 LM83_MAX_ALARM_BIT[] = {
87	BIT(6), BIT(7), BIT(4), BIT(4)
88};
89
90static const u8 LM83_CRIT_ALARM_BIT[] = {
91	BIT(0), BIT(0), BIT(1), BIT(1)
92};
93
94static 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
102struct lm83_data {
103	struct regmap *regmap;
104	enum chips type;
105};
106
107/* regmap code */
108
109static 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 */
128static 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
150static 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
165static 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
176static 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
225static 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
250static 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
274static 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
287static 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
298static 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
340static 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
355static const struct hwmon_ops lm83_hwmon_ops = {
356	.is_visible = lm83_is_visible,
357	.read = lm83_read,
358	.write = lm83_write,
359};
360
361static 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 */
367static 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
420static const struct i2c_device_id lm83_id[] = {
421	{ "lm83", lm83 },
422	{ "lm82", lm82 },
423	{ }
424};
425MODULE_DEVICE_TABLE(i2c, lm83_id);
426
427static 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
452static 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
463module_i2c_driver(lm83_driver);
464
465MODULE_AUTHOR("Jean Delvare <jdelvare@suse.de>");
466MODULE_DESCRIPTION("LM83 driver");
467MODULE_LICENSE("GPL");
468