1/*
2 * Copyright (C) 2011 Alexander Stein <alexander.stein@systec-electronic.com>
3 *
4 * The LM95245 is a sensor chip made by TI / National Semiconductor.
5 * It reports up to two temperatures (its own plus an external one).
6 *
7 * This driver is based on lm95241.c
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23
24#include <linux/module.h>
25#include <linux/init.h>
26#include <linux/slab.h>
27#include <linux/jiffies.h>
28#include <linux/i2c.h>
29#include <linux/hwmon.h>
30#include <linux/hwmon-sysfs.h>
31#include <linux/err.h>
32#include <linux/mutex.h>
33#include <linux/sysfs.h>
34
35static const unsigned short normal_i2c[] = {
36	0x18, 0x19, 0x29, 0x4c, 0x4d, I2C_CLIENT_END };
37
38/* LM95245 registers */
39/* general registers */
40#define LM95245_REG_RW_CONFIG1		0x03
41#define LM95245_REG_RW_CONVERS_RATE	0x04
42#define LM95245_REG_W_ONE_SHOT		0x0F
43
44/* diode configuration */
45#define LM95245_REG_RW_CONFIG2		0xBF
46#define LM95245_REG_RW_REMOTE_OFFH	0x11
47#define LM95245_REG_RW_REMOTE_OFFL	0x12
48
49/* status registers */
50#define LM95245_REG_R_STATUS1		0x02
51#define LM95245_REG_R_STATUS2		0x33
52
53/* limit registers */
54#define LM95245_REG_RW_REMOTE_OS_LIMIT		0x07
55#define LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT	0x20
56#define LM95245_REG_RW_REMOTE_TCRIT_LIMIT	0x19
57#define LM95245_REG_RW_COMMON_HYSTERESIS	0x21
58
59/* temperature signed */
60#define LM95245_REG_R_LOCAL_TEMPH_S	0x00
61#define LM95245_REG_R_LOCAL_TEMPL_S	0x30
62#define LM95245_REG_R_REMOTE_TEMPH_S	0x01
63#define LM95245_REG_R_REMOTE_TEMPL_S	0x10
64/* temperature unsigned */
65#define LM95245_REG_R_REMOTE_TEMPH_U	0x31
66#define LM95245_REG_R_REMOTE_TEMPL_U	0x32
67
68/* id registers */
69#define LM95245_REG_R_MAN_ID		0xFE
70#define LM95245_REG_R_CHIP_ID		0xFF
71
72/* LM95245 specific bitfields */
73#define CFG_STOP		0x40
74#define CFG_REMOTE_TCRIT_MASK	0x10
75#define CFG_REMOTE_OS_MASK	0x08
76#define CFG_LOCAL_TCRIT_MASK	0x04
77#define CFG_LOCAL_OS_MASK	0x02
78
79#define CFG2_OS_A0		0x40
80#define CFG2_DIODE_FAULT_OS	0x20
81#define CFG2_DIODE_FAULT_TCRIT	0x10
82#define CFG2_REMOTE_TT		0x08
83#define CFG2_REMOTE_FILTER_DIS	0x00
84#define CFG2_REMOTE_FILTER_EN	0x06
85
86/* conversation rate in ms */
87#define RATE_CR0063	0x00
88#define RATE_CR0364	0x01
89#define RATE_CR1000	0x02
90#define RATE_CR2500	0x03
91
92#define STATUS1_DIODE_FAULT	0x04
93#define STATUS1_RTCRIT		0x02
94#define STATUS1_LOC		0x01
95
96#define MANUFACTURER_ID		0x01
97#define LM95235_REVISION	0xB1
98#define LM95245_REVISION	0xB3
99
100static const u8 lm95245_reg_address[] = {
101	LM95245_REG_R_LOCAL_TEMPH_S,
102	LM95245_REG_R_LOCAL_TEMPL_S,
103	LM95245_REG_R_REMOTE_TEMPH_S,
104	LM95245_REG_R_REMOTE_TEMPL_S,
105	LM95245_REG_R_REMOTE_TEMPH_U,
106	LM95245_REG_R_REMOTE_TEMPL_U,
107	LM95245_REG_RW_LOCAL_OS_TCRIT_LIMIT,
108	LM95245_REG_RW_REMOTE_TCRIT_LIMIT,
109	LM95245_REG_RW_COMMON_HYSTERESIS,
110	LM95245_REG_R_STATUS1,
111};
112
113/* Client data (each client gets its own) */
114struct lm95245_data {
115	struct i2c_client *client;
116	struct mutex update_lock;
117	unsigned long last_updated;	/* in jiffies */
118	unsigned long interval;	/* in msecs */
119	bool valid;		/* zero until following fields are valid */
120	/* registers values */
121	u8 regs[ARRAY_SIZE(lm95245_reg_address)];
122	u8 config1, config2;
123};
124
125/* Conversions */
126static int temp_from_reg_unsigned(u8 val_h, u8 val_l)
127{
128	return val_h * 1000 + val_l * 1000 / 256;
129}
130
131static int temp_from_reg_signed(u8 val_h, u8 val_l)
132{
133	if (val_h & 0x80)
134		return (val_h - 0x100) * 1000;
135	return temp_from_reg_unsigned(val_h, val_l);
136}
137
138static struct lm95245_data *lm95245_update_device(struct device *dev)
139{
140	struct lm95245_data *data = dev_get_drvdata(dev);
141	struct i2c_client *client = data->client;
142
143	mutex_lock(&data->update_lock);
144
145	if (time_after(jiffies, data->last_updated
146		+ msecs_to_jiffies(data->interval)) || !data->valid) {
147		int i;
148
149		for (i = 0; i < ARRAY_SIZE(lm95245_reg_address); i++)
150			data->regs[i]
151			  = i2c_smbus_read_byte_data(client,
152						     lm95245_reg_address[i]);
153		data->last_updated = jiffies;
154		data->valid = 1;
155	}
156
157	mutex_unlock(&data->update_lock);
158
159	return data;
160}
161
162static unsigned long lm95245_read_conversion_rate(struct i2c_client *client)
163{
164	int rate;
165	unsigned long interval;
166
167	rate = i2c_smbus_read_byte_data(client, LM95245_REG_RW_CONVERS_RATE);
168
169	switch (rate) {
170	case RATE_CR0063:
171		interval = 63;
172		break;
173	case RATE_CR0364:
174		interval = 364;
175		break;
176	case RATE_CR1000:
177		interval = 1000;
178		break;
179	case RATE_CR2500:
180	default:
181		interval = 2500;
182		break;
183	}
184
185	return interval;
186}
187
188static unsigned long lm95245_set_conversion_rate(struct i2c_client *client,
189			unsigned long interval)
190{
191	int rate;
192
193	if (interval <= 63) {
194		interval = 63;
195		rate = RATE_CR0063;
196	} else if (interval <= 364) {
197		interval = 364;
198		rate = RATE_CR0364;
199	} else if (interval <= 1000) {
200		interval = 1000;
201		rate = RATE_CR1000;
202	} else {
203		interval = 2500;
204		rate = RATE_CR2500;
205	}
206
207	i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONVERS_RATE, rate);
208
209	return interval;
210}
211
212/* Sysfs stuff */
213static ssize_t show_input(struct device *dev, struct device_attribute *attr,
214			  char *buf)
215{
216	struct lm95245_data *data = lm95245_update_device(dev);
217	int temp;
218	int index = to_sensor_dev_attr(attr)->index;
219
220	/*
221	 * Index 0 (Local temp) is always signed
222	 * Index 2 (Remote temp) has both signed and unsigned data
223	 * use signed calculation for remote if signed bit is set
224	 */
225	if (index == 0 || data->regs[index] & 0x80)
226		temp = temp_from_reg_signed(data->regs[index],
227			    data->regs[index + 1]);
228	else
229		temp = temp_from_reg_unsigned(data->regs[index + 2],
230			    data->regs[index + 3]);
231
232	return snprintf(buf, PAGE_SIZE - 1, "%d\n", temp);
233}
234
235static ssize_t show_limit(struct device *dev, struct device_attribute *attr,
236			 char *buf)
237{
238	struct lm95245_data *data = lm95245_update_device(dev);
239	int index = to_sensor_dev_attr(attr)->index;
240
241	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
242			data->regs[index] * 1000);
243}
244
245static ssize_t set_limit(struct device *dev, struct device_attribute *attr,
246			const char *buf, size_t count)
247{
248	struct lm95245_data *data = dev_get_drvdata(dev);
249	int index = to_sensor_dev_attr(attr)->index;
250	struct i2c_client *client = data->client;
251	unsigned long val;
252
253	if (kstrtoul(buf, 10, &val) < 0)
254		return -EINVAL;
255
256	val /= 1000;
257
258	val = clamp_val(val, 0, (index == 6 ? 127 : 255));
259
260	mutex_lock(&data->update_lock);
261
262	data->valid = 0;
263
264	i2c_smbus_write_byte_data(client, lm95245_reg_address[index], val);
265
266	mutex_unlock(&data->update_lock);
267
268	return count;
269}
270
271static ssize_t show_crit_hyst(struct device *dev, struct device_attribute *attr,
272			char *buf)
273{
274	struct lm95245_data *data = lm95245_update_device(dev);
275	int index = to_sensor_dev_attr(attr)->index;
276	int hyst = data->regs[index] - data->regs[8];
277
278	return snprintf(buf, PAGE_SIZE - 1, "%d\n", hyst * 1000);
279}
280
281static ssize_t set_crit_hyst(struct device *dev, struct device_attribute *attr,
282			const char *buf, size_t count)
283{
284	struct lm95245_data *data = dev_get_drvdata(dev);
285	int index = to_sensor_dev_attr(attr)->index;
286	struct i2c_client *client = data->client;
287	unsigned long val;
288	int hyst, limit;
289
290	if (kstrtoul(buf, 10, &val) < 0)
291		return -EINVAL;
292
293	mutex_lock(&data->update_lock);
294
295	limit = i2c_smbus_read_byte_data(client, lm95245_reg_address[index]);
296	hyst = limit - val / 1000;
297	hyst = clamp_val(hyst, 0, 31);
298	data->regs[8] = hyst;
299
300	/* shared crit hysteresis */
301	i2c_smbus_write_byte_data(client, LM95245_REG_RW_COMMON_HYSTERESIS,
302		hyst);
303
304	mutex_unlock(&data->update_lock);
305
306	return count;
307}
308
309static ssize_t show_type(struct device *dev, struct device_attribute *attr,
310			 char *buf)
311{
312	struct lm95245_data *data = dev_get_drvdata(dev);
313
314	return snprintf(buf, PAGE_SIZE - 1,
315		data->config2 & CFG2_REMOTE_TT ? "1\n" : "2\n");
316}
317
318static ssize_t set_type(struct device *dev, struct device_attribute *attr,
319			const char *buf, size_t count)
320{
321	struct lm95245_data *data = dev_get_drvdata(dev);
322	struct i2c_client *client = data->client;
323	unsigned long val;
324
325	if (kstrtoul(buf, 10, &val) < 0)
326		return -EINVAL;
327	if (val != 1 && val != 2)
328		return -EINVAL;
329
330	mutex_lock(&data->update_lock);
331
332	if (val == 1)
333		data->config2 |= CFG2_REMOTE_TT;
334	else
335		data->config2 &= ~CFG2_REMOTE_TT;
336
337	data->valid = 0;
338
339	i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG2,
340				  data->config2);
341
342	mutex_unlock(&data->update_lock);
343
344	return count;
345}
346
347static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
348			 char *buf)
349{
350	struct lm95245_data *data = lm95245_update_device(dev);
351	int index = to_sensor_dev_attr(attr)->index;
352
353	return snprintf(buf, PAGE_SIZE - 1, "%d\n",
354			!!(data->regs[9] & index));
355}
356
357static ssize_t show_interval(struct device *dev, struct device_attribute *attr,
358			     char *buf)
359{
360	struct lm95245_data *data = lm95245_update_device(dev);
361
362	return snprintf(buf, PAGE_SIZE - 1, "%lu\n", data->interval);
363}
364
365static ssize_t set_interval(struct device *dev, struct device_attribute *attr,
366			    const char *buf, size_t count)
367{
368	struct lm95245_data *data = dev_get_drvdata(dev);
369	struct i2c_client *client = data->client;
370	unsigned long val;
371
372	if (kstrtoul(buf, 10, &val) < 0)
373		return -EINVAL;
374
375	mutex_lock(&data->update_lock);
376
377	data->interval = lm95245_set_conversion_rate(client, val);
378
379	mutex_unlock(&data->update_lock);
380
381	return count;
382}
383
384static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_input, NULL, 0);
385static SENSOR_DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO, show_limit,
386		set_limit, 6);
387static SENSOR_DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO, show_crit_hyst,
388		set_crit_hyst, 6);
389static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
390		STATUS1_LOC);
391
392static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_input, NULL, 2);
393static SENSOR_DEVICE_ATTR(temp2_crit, S_IWUSR | S_IRUGO, show_limit,
394		set_limit, 7);
395static SENSOR_DEVICE_ATTR(temp2_crit_hyst, S_IRUGO, show_crit_hyst, NULL, 7);
396static SENSOR_DEVICE_ATTR(temp2_crit_alarm, S_IRUGO, show_alarm, NULL,
397		STATUS1_RTCRIT);
398static SENSOR_DEVICE_ATTR(temp2_type, S_IWUSR | S_IRUGO, show_type,
399		set_type, 0);
400static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_alarm, NULL,
401		STATUS1_DIODE_FAULT);
402
403static DEVICE_ATTR(update_interval, S_IWUSR | S_IRUGO, show_interval,
404		set_interval);
405
406static struct attribute *lm95245_attrs[] = {
407	&sensor_dev_attr_temp1_input.dev_attr.attr,
408	&sensor_dev_attr_temp1_crit.dev_attr.attr,
409	&sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
410	&sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
411	&sensor_dev_attr_temp2_input.dev_attr.attr,
412	&sensor_dev_attr_temp2_crit.dev_attr.attr,
413	&sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
414	&sensor_dev_attr_temp2_crit_alarm.dev_attr.attr,
415	&sensor_dev_attr_temp2_type.dev_attr.attr,
416	&sensor_dev_attr_temp2_fault.dev_attr.attr,
417	&dev_attr_update_interval.attr,
418	NULL
419};
420ATTRIBUTE_GROUPS(lm95245);
421
422/* Return 0 if detection is successful, -ENODEV otherwise */
423static int lm95245_detect(struct i2c_client *new_client,
424			  struct i2c_board_info *info)
425{
426	struct i2c_adapter *adapter = new_client->adapter;
427	int address = new_client->addr;
428	const char *name;
429	int rev, id;
430
431	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
432		return -ENODEV;
433
434	id = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_MAN_ID);
435	if (id != MANUFACTURER_ID)
436		return -ENODEV;
437
438	rev = i2c_smbus_read_byte_data(new_client, LM95245_REG_R_CHIP_ID);
439	switch (rev) {
440	case LM95235_REVISION:
441		if (address != 0x18 && address != 0x29 && address != 0x4c)
442			return -ENODEV;
443		name = "lm95235";
444		break;
445	case LM95245_REVISION:
446		name = "lm95245";
447		break;
448	default:
449		return -ENODEV;
450	}
451
452	strlcpy(info->type, name, I2C_NAME_SIZE);
453	return 0;
454}
455
456static void lm95245_init_client(struct i2c_client *client,
457				struct lm95245_data *data)
458{
459	data->interval = lm95245_read_conversion_rate(client);
460
461	data->config1 = i2c_smbus_read_byte_data(client,
462		LM95245_REG_RW_CONFIG1);
463	data->config2 = i2c_smbus_read_byte_data(client,
464		LM95245_REG_RW_CONFIG2);
465
466	if (data->config1 & CFG_STOP) {
467		/* Clear the standby bit */
468		data->config1 &= ~CFG_STOP;
469		i2c_smbus_write_byte_data(client, LM95245_REG_RW_CONFIG1,
470			data->config1);
471	}
472}
473
474static int lm95245_probe(struct i2c_client *client,
475			 const struct i2c_device_id *id)
476{
477	struct device *dev = &client->dev;
478	struct lm95245_data *data;
479	struct device *hwmon_dev;
480
481	data = devm_kzalloc(dev, sizeof(struct lm95245_data), GFP_KERNEL);
482	if (!data)
483		return -ENOMEM;
484
485	data->client = client;
486	mutex_init(&data->update_lock);
487
488	/* Initialize the LM95245 chip */
489	lm95245_init_client(client, data);
490
491	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
492							   data,
493							   lm95245_groups);
494	return PTR_ERR_OR_ZERO(hwmon_dev);
495}
496
497/* Driver data (common to all clients) */
498static const struct i2c_device_id lm95245_id[] = {
499	{ "lm95235", 0 },
500	{ "lm95245", 0 },
501	{ }
502};
503MODULE_DEVICE_TABLE(i2c, lm95245_id);
504
505static struct i2c_driver lm95245_driver = {
506	.class		= I2C_CLASS_HWMON,
507	.driver = {
508		.name	= "lm95245",
509	},
510	.probe		= lm95245_probe,
511	.id_table	= lm95245_id,
512	.detect		= lm95245_detect,
513	.address_list	= normal_i2c,
514};
515
516module_i2c_driver(lm95245_driver);
517
518MODULE_AUTHOR("Alexander Stein <alexander.stein@systec-electronic.com>");
519MODULE_DESCRIPTION("LM95235/LM95245 sensor driver");
520MODULE_LICENSE("GPL");
521