1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) 2008, 2010 Davide Rizzo <elpa.rizzo@gmail.com>
4 *
5 * The LM95241 is a sensor chip made by National Semiconductors.
6 * It reports up to three temperatures (its own plus up to two external ones).
7 * Complete datasheet can be obtained from National's website at:
8 *   http://www.national.com/ds.cgi/LM/LM95241.pdf
9 */
10
11#include <linux/bitops.h>
12#include <linux/err.h>
13#include <linux/i2c.h>
14#include <linux/init.h>
15#include <linux/jiffies.h>
16#include <linux/hwmon.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/slab.h>
20
21#define DEVNAME "lm95241"
22
23static const unsigned short normal_i2c[] = {
24	0x19, 0x2a, 0x2b, I2C_CLIENT_END };
25
26/* LM95241 registers */
27#define LM95241_REG_R_MAN_ID		0xFE
28#define LM95241_REG_R_CHIP_ID		0xFF
29#define LM95241_REG_R_STATUS		0x02
30#define LM95241_REG_RW_CONFIG		0x03
31#define LM95241_REG_RW_REM_FILTER	0x06
32#define LM95241_REG_RW_TRUTHERM		0x07
33#define LM95241_REG_W_ONE_SHOT		0x0F
34#define LM95241_REG_R_LOCAL_TEMPH	0x10
35#define LM95241_REG_R_REMOTE1_TEMPH	0x11
36#define LM95241_REG_R_REMOTE2_TEMPH	0x12
37#define LM95241_REG_R_LOCAL_TEMPL	0x20
38#define LM95241_REG_R_REMOTE1_TEMPL	0x21
39#define LM95241_REG_R_REMOTE2_TEMPL	0x22
40#define LM95241_REG_RW_REMOTE_MODEL	0x30
41
42/* LM95241 specific bitfields */
43#define CFG_STOP	BIT(6)
44#define CFG_CR0076	0x00
45#define CFG_CR0182	BIT(4)
46#define CFG_CR1000	BIT(5)
47#define CFG_CR2700	(BIT(4) | BIT(5))
48#define CFG_CRMASK	(BIT(4) | BIT(5))
49#define R1MS_MASK	BIT(0)
50#define R2MS_MASK	BIT(2)
51#define R1DF_MASK	BIT(1)
52#define R2DF_MASK	BIT(2)
53#define R1FE_MASK	BIT(0)
54#define R2FE_MASK	BIT(2)
55#define R1DM		BIT(0)
56#define R2DM		BIT(1)
57#define TT1_SHIFT	0
58#define TT2_SHIFT	4
59#define TT_OFF		0
60#define TT_ON		1
61#define TT_MASK		7
62#define NATSEMI_MAN_ID	0x01
63#define LM95231_CHIP_ID	0xA1
64#define LM95241_CHIP_ID	0xA4
65
66static const u8 lm95241_reg_address[] = {
67	LM95241_REG_R_LOCAL_TEMPH,
68	LM95241_REG_R_LOCAL_TEMPL,
69	LM95241_REG_R_REMOTE1_TEMPH,
70	LM95241_REG_R_REMOTE1_TEMPL,
71	LM95241_REG_R_REMOTE2_TEMPH,
72	LM95241_REG_R_REMOTE2_TEMPL
73};
74
75/* Client data (each client gets its own) */
76struct lm95241_data {
77	struct i2c_client *client;
78	struct mutex update_lock;
79	unsigned long last_updated;	/* in jiffies */
80	unsigned long interval;		/* in milli-seconds */
81	bool valid;		/* false until following fields are valid */
82	/* registers values */
83	u8 temp[ARRAY_SIZE(lm95241_reg_address)];
84	u8 status, config, model, trutherm;
85};
86
87/* Conversions */
88static int temp_from_reg_signed(u8 val_h, u8 val_l)
89{
90	s16 val_hl = (val_h << 8) | val_l;
91	return val_hl * 1000 / 256;
92}
93
94static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
95{
96	u16 val_hl = (val_h << 8) | val_l;
97	return val_hl * 1000 / 256;
98}
99
100static struct lm95241_data *lm95241_update_device(struct device *dev)
101{
102	struct lm95241_data *data = dev_get_drvdata(dev);
103	struct i2c_client *client = data->client;
104
105	mutex_lock(&data->update_lock);
106
107	if (time_after(jiffies, data->last_updated
108		       + msecs_to_jiffies(data->interval)) ||
109	    !data->valid) {
110		int i;
111
112		dev_dbg(dev, "Updating lm95241 data.\n");
113		for (i = 0; i < ARRAY_SIZE(lm95241_reg_address); i++)
114			data->temp[i]
115			  = i2c_smbus_read_byte_data(client,
116						     lm95241_reg_address[i]);
117
118		data->status = i2c_smbus_read_byte_data(client,
119							LM95241_REG_R_STATUS);
120		data->last_updated = jiffies;
121		data->valid = true;
122	}
123
124	mutex_unlock(&data->update_lock);
125
126	return data;
127}
128
129static int lm95241_read_chip(struct device *dev, u32 attr, int channel,
130			     long *val)
131{
132	struct lm95241_data *data = dev_get_drvdata(dev);
133
134	switch (attr) {
135	case hwmon_chip_update_interval:
136		*val = data->interval;
137		return 0;
138	default:
139		return -EOPNOTSUPP;
140	}
141}
142
143static int lm95241_read_temp(struct device *dev, u32 attr, int channel,
144			     long *val)
145{
146	struct lm95241_data *data = lm95241_update_device(dev);
147
148	switch (attr) {
149	case hwmon_temp_input:
150		if (!channel || (data->config & BIT(channel - 1)))
151			*val = temp_from_reg_signed(data->temp[channel * 2],
152						data->temp[channel * 2 + 1]);
153		else
154			*val = temp_from_reg_unsigned(data->temp[channel * 2],
155						data->temp[channel * 2 + 1]);
156		return 0;
157	case hwmon_temp_min:
158		if (channel == 1)
159			*val = (data->config & R1DF_MASK) ? -128000 : 0;
160		else
161			*val = (data->config & R2DF_MASK) ? -128000 : 0;
162		return 0;
163	case hwmon_temp_max:
164		if (channel == 1)
165			*val = (data->config & R1DF_MASK) ? 127875 : 255875;
166		else
167			*val = (data->config & R2DF_MASK) ? 127875 : 255875;
168		return 0;
169	case hwmon_temp_type:
170		if (channel == 1)
171			*val = (data->model & R1MS_MASK) ? 1 : 2;
172		else
173			*val = (data->model & R2MS_MASK) ? 1 : 2;
174		return 0;
175	case hwmon_temp_fault:
176		if (channel == 1)
177			*val = !!(data->status & R1DM);
178		else
179			*val = !!(data->status & R2DM);
180		return 0;
181	default:
182		return -EOPNOTSUPP;
183	}
184}
185
186static int lm95241_read(struct device *dev, enum hwmon_sensor_types type,
187			u32 attr, int channel, long *val)
188{
189	switch (type) {
190	case hwmon_chip:
191		return lm95241_read_chip(dev, attr, channel, val);
192	case hwmon_temp:
193		return lm95241_read_temp(dev, attr, channel, val);
194	default:
195		return -EOPNOTSUPP;
196	}
197}
198
199static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
200			      long val)
201{
202	struct lm95241_data *data = dev_get_drvdata(dev);
203	int convrate;
204	u8 config;
205	int ret;
206
207	mutex_lock(&data->update_lock);
208
209	switch (attr) {
210	case hwmon_chip_update_interval:
211		config = data->config & ~CFG_CRMASK;
212		if (val < 130) {
213			convrate = 76;
214			config |= CFG_CR0076;
215		} else if (val < 590) {
216			convrate = 182;
217			config |= CFG_CR0182;
218		} else if (val < 1850) {
219			convrate = 1000;
220			config |= CFG_CR1000;
221		} else {
222			convrate = 2700;
223			config |= CFG_CR2700;
224		}
225		data->interval = convrate;
226		data->config = config;
227		ret = i2c_smbus_write_byte_data(data->client,
228						LM95241_REG_RW_CONFIG, config);
229		break;
230	default:
231		ret = -EOPNOTSUPP;
232		break;
233	}
234	mutex_unlock(&data->update_lock);
235	return ret;
236}
237
238static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
239			      long val)
240{
241	struct lm95241_data *data = dev_get_drvdata(dev);
242	struct i2c_client *client = data->client;
243	int ret;
244
245	mutex_lock(&data->update_lock);
246
247	switch (attr) {
248	case hwmon_temp_min:
249		if (channel == 1) {
250			if (val < 0)
251				data->config |= R1DF_MASK;
252			else
253				data->config &= ~R1DF_MASK;
254		} else {
255			if (val < 0)
256				data->config |= R2DF_MASK;
257			else
258				data->config &= ~R2DF_MASK;
259		}
260		data->valid = false;
261		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
262						data->config);
263		break;
264	case hwmon_temp_max:
265		if (channel == 1) {
266			if (val <= 127875)
267				data->config |= R1DF_MASK;
268			else
269				data->config &= ~R1DF_MASK;
270		} else {
271			if (val <= 127875)
272				data->config |= R2DF_MASK;
273			else
274				data->config &= ~R2DF_MASK;
275		}
276		data->valid = false;
277		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG,
278						data->config);
279		break;
280	case hwmon_temp_type:
281		if (val != 1 && val != 2) {
282			ret = -EINVAL;
283			break;
284		}
285		if (channel == 1) {
286			data->trutherm &= ~(TT_MASK << TT1_SHIFT);
287			if (val == 1) {
288				data->model |= R1MS_MASK;
289				data->trutherm |= (TT_ON << TT1_SHIFT);
290			} else {
291				data->model &= ~R1MS_MASK;
292				data->trutherm |= (TT_OFF << TT1_SHIFT);
293			}
294		} else {
295			data->trutherm &= ~(TT_MASK << TT2_SHIFT);
296			if (val == 1) {
297				data->model |= R2MS_MASK;
298				data->trutherm |= (TT_ON << TT2_SHIFT);
299			} else {
300				data->model &= ~R2MS_MASK;
301				data->trutherm |= (TT_OFF << TT2_SHIFT);
302			}
303		}
304		ret = i2c_smbus_write_byte_data(client,
305						LM95241_REG_RW_REMOTE_MODEL,
306						data->model);
307		if (ret < 0)
308			break;
309		ret = i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
310						data->trutherm);
311		break;
312	default:
313		ret = -EOPNOTSUPP;
314		break;
315	}
316
317	mutex_unlock(&data->update_lock);
318
319	return ret;
320}
321
322static int lm95241_write(struct device *dev, enum hwmon_sensor_types type,
323			 u32 attr, int channel, long val)
324{
325	switch (type) {
326	case hwmon_chip:
327		return lm95241_write_chip(dev, attr, channel, val);
328	case hwmon_temp:
329		return lm95241_write_temp(dev, attr, channel, val);
330	default:
331		return -EOPNOTSUPP;
332	}
333}
334
335static umode_t lm95241_is_visible(const void *data,
336				  enum hwmon_sensor_types type,
337				  u32 attr, int channel)
338{
339	switch (type) {
340	case hwmon_chip:
341		switch (attr) {
342		case hwmon_chip_update_interval:
343			return 0644;
344		}
345		break;
346	case hwmon_temp:
347		switch (attr) {
348		case hwmon_temp_input:
349			return 0444;
350		case hwmon_temp_fault:
351			return 0444;
352		case hwmon_temp_min:
353		case hwmon_temp_max:
354		case hwmon_temp_type:
355			return 0644;
356		}
357		break;
358	default:
359		break;
360	}
361	return 0;
362}
363
364/* Return 0 if detection is successful, -ENODEV otherwise */
365static int lm95241_detect(struct i2c_client *new_client,
366			  struct i2c_board_info *info)
367{
368	struct i2c_adapter *adapter = new_client->adapter;
369	const char *name;
370	int mfg_id, chip_id;
371
372	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
373		return -ENODEV;
374
375	mfg_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_MAN_ID);
376	if (mfg_id != NATSEMI_MAN_ID)
377		return -ENODEV;
378
379	chip_id = i2c_smbus_read_byte_data(new_client, LM95241_REG_R_CHIP_ID);
380	switch (chip_id) {
381	case LM95231_CHIP_ID:
382		name = "lm95231";
383		break;
384	case LM95241_CHIP_ID:
385		name = "lm95241";
386		break;
387	default:
388		return -ENODEV;
389	}
390
391	/* Fill the i2c board info */
392	strscpy(info->type, name, I2C_NAME_SIZE);
393	return 0;
394}
395
396static void lm95241_init_client(struct i2c_client *client,
397				struct lm95241_data *data)
398{
399	data->interval = 1000;
400	data->config = CFG_CR1000;
401	data->trutherm = (TT_OFF << TT1_SHIFT) | (TT_OFF << TT2_SHIFT);
402
403	i2c_smbus_write_byte_data(client, LM95241_REG_RW_CONFIG, data->config);
404	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REM_FILTER,
405				  R1FE_MASK | R2FE_MASK);
406	i2c_smbus_write_byte_data(client, LM95241_REG_RW_TRUTHERM,
407				  data->trutherm);
408	i2c_smbus_write_byte_data(client, LM95241_REG_RW_REMOTE_MODEL,
409				  data->model);
410}
411
412static const struct hwmon_channel_info * const lm95241_info[] = {
413	HWMON_CHANNEL_INFO(chip,
414			   HWMON_C_UPDATE_INTERVAL),
415	HWMON_CHANNEL_INFO(temp,
416			   HWMON_T_INPUT,
417			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
418			   HWMON_T_TYPE | HWMON_T_FAULT,
419			   HWMON_T_INPUT | HWMON_T_MAX | HWMON_T_MIN |
420			   HWMON_T_TYPE | HWMON_T_FAULT),
421	NULL
422};
423
424static const struct hwmon_ops lm95241_hwmon_ops = {
425	.is_visible = lm95241_is_visible,
426	.read = lm95241_read,
427	.write = lm95241_write,
428};
429
430static const struct hwmon_chip_info lm95241_chip_info = {
431	.ops = &lm95241_hwmon_ops,
432	.info = lm95241_info,
433};
434
435static int lm95241_probe(struct i2c_client *client)
436{
437	struct device *dev = &client->dev;
438	struct lm95241_data *data;
439	struct device *hwmon_dev;
440
441	data = devm_kzalloc(dev, sizeof(struct lm95241_data), GFP_KERNEL);
442	if (!data)
443		return -ENOMEM;
444
445	data->client = client;
446	mutex_init(&data->update_lock);
447
448	/* Initialize the LM95241 chip */
449	lm95241_init_client(client, data);
450
451	hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
452							   data,
453							   &lm95241_chip_info,
454							   NULL);
455	return PTR_ERR_OR_ZERO(hwmon_dev);
456}
457
458/* Driver data (common to all clients) */
459static const struct i2c_device_id lm95241_id[] = {
460	{ "lm95231", 0 },
461	{ "lm95241", 0 },
462	{ }
463};
464MODULE_DEVICE_TABLE(i2c, lm95241_id);
465
466static struct i2c_driver lm95241_driver = {
467	.class		= I2C_CLASS_HWMON,
468	.driver = {
469		.name	= DEVNAME,
470	},
471	.probe		= lm95241_probe,
472	.id_table	= lm95241_id,
473	.detect		= lm95241_detect,
474	.address_list	= normal_i2c,
475};
476
477module_i2c_driver(lm95241_driver);
478
479MODULE_AUTHOR("Davide Rizzo <elpa.rizzo@gmail.com>");
480MODULE_DESCRIPTION("LM95231/LM95241 sensor driver");
481MODULE_LICENSE("GPL");
482