1/*
2 * Driver for TI ADC128D818 System Monitor with Temperature Sensor
3 *
4 * Copyright (c) 2014 Guenter Roeck
5 *
6 * Derived from lm80.c
7 * Copyright (C) 1998, 1999  Frodo Looijaard <frodol@dds.nl>
8 *			     and Philip Edelbrock <phil@netroedge.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 * GNU General Public License for more details.
19 */
20
21#include <linux/module.h>
22#include <linux/slab.h>
23#include <linux/jiffies.h>
24#include <linux/i2c.h>
25#include <linux/hwmon.h>
26#include <linux/hwmon-sysfs.h>
27#include <linux/err.h>
28#include <linux/regulator/consumer.h>
29#include <linux/mutex.h>
30#include <linux/bitops.h>
31
32/* Addresses to scan
33 * The chip also supports addresses 0x35..0x37. Don't scan those addresses
34 * since they are also used by some EEPROMs, which may result in false
35 * positives.
36 */
37static const unsigned short normal_i2c[] = {
38	0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END };
39
40/* registers */
41#define ADC128_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
42#define ADC128_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
43#define ADC128_REG_IN(nr)		(0x20 + (nr))
44
45#define ADC128_REG_TEMP			0x27
46#define ADC128_REG_TEMP_MAX		0x38
47#define ADC128_REG_TEMP_HYST		0x39
48
49#define ADC128_REG_CONFIG		0x00
50#define ADC128_REG_ALARM		0x01
51#define ADC128_REG_MASK			0x03
52#define ADC128_REG_CONV_RATE		0x07
53#define ADC128_REG_ONESHOT		0x09
54#define ADC128_REG_SHUTDOWN		0x0a
55#define ADC128_REG_CONFIG_ADV		0x0b
56#define ADC128_REG_BUSY_STATUS		0x0c
57
58#define ADC128_REG_MAN_ID		0x3e
59#define ADC128_REG_DEV_ID		0x3f
60
61struct adc128_data {
62	struct i2c_client *client;
63	struct regulator *regulator;
64	int vref;		/* Reference voltage in mV */
65	struct mutex update_lock;
66	bool valid;		/* true if following fields are valid */
67	unsigned long last_updated;	/* In jiffies */
68
69	u16 in[3][7];		/* Register value, normalized to 12 bit
70				 * 0: input voltage
71				 * 1: min limit
72				 * 2: max limit
73				 */
74	s16 temp[3];		/* Register value, normalized to 9 bit
75				 * 0: sensor 1: limit 2: hyst
76				 */
77	u8 alarms;		/* alarm register value */
78};
79
80static struct adc128_data *adc128_update_device(struct device *dev)
81{
82	struct adc128_data *data = dev_get_drvdata(dev);
83	struct i2c_client *client = data->client;
84	struct adc128_data *ret = data;
85	int i, rv;
86
87	mutex_lock(&data->update_lock);
88
89	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
90		for (i = 0; i < 7; i++) {
91			rv = i2c_smbus_read_word_swapped(client,
92							 ADC128_REG_IN(i));
93			if (rv < 0)
94				goto abort;
95			data->in[0][i] = rv >> 4;
96
97			rv = i2c_smbus_read_byte_data(client,
98						      ADC128_REG_IN_MIN(i));
99			if (rv < 0)
100				goto abort;
101			data->in[1][i] = rv << 4;
102
103			rv = i2c_smbus_read_byte_data(client,
104						      ADC128_REG_IN_MAX(i));
105			if (rv < 0)
106				goto abort;
107			data->in[2][i] = rv << 4;
108		}
109
110		rv = i2c_smbus_read_word_swapped(client, ADC128_REG_TEMP);
111		if (rv < 0)
112			goto abort;
113		data->temp[0] = rv >> 7;
114
115		rv = i2c_smbus_read_byte_data(client, ADC128_REG_TEMP_MAX);
116		if (rv < 0)
117			goto abort;
118		data->temp[1] = rv << 1;
119
120		rv = i2c_smbus_read_byte_data(client, ADC128_REG_TEMP_HYST);
121		if (rv < 0)
122			goto abort;
123		data->temp[2] = rv << 1;
124
125		rv = i2c_smbus_read_byte_data(client, ADC128_REG_ALARM);
126		if (rv < 0)
127			goto abort;
128		data->alarms |= rv;
129
130		data->last_updated = jiffies;
131		data->valid = true;
132	}
133	goto done;
134
135abort:
136	ret = ERR_PTR(rv);
137	data->valid = false;
138done:
139	mutex_unlock(&data->update_lock);
140	return ret;
141}
142
143static ssize_t adc128_show_in(struct device *dev, struct device_attribute *attr,
144			      char *buf)
145{
146	struct adc128_data *data = adc128_update_device(dev);
147	int index = to_sensor_dev_attr_2(attr)->index;
148	int nr = to_sensor_dev_attr_2(attr)->nr;
149	int val;
150
151	if (IS_ERR(data))
152		return PTR_ERR(data);
153
154	val = DIV_ROUND_CLOSEST(data->in[index][nr] * data->vref, 4095);
155	return sprintf(buf, "%d\n", val);
156}
157
158static ssize_t adc128_set_in(struct device *dev, struct device_attribute *attr,
159			     const char *buf, size_t count)
160{
161	struct adc128_data *data = dev_get_drvdata(dev);
162	int index = to_sensor_dev_attr_2(attr)->index;
163	int nr = to_sensor_dev_attr_2(attr)->nr;
164	u8 reg, regval;
165	long val;
166	int err;
167
168	err = kstrtol(buf, 10, &val);
169	if (err < 0)
170		return err;
171
172	mutex_lock(&data->update_lock);
173	/* 10 mV LSB on limit registers */
174	regval = clamp_val(DIV_ROUND_CLOSEST(val, 10), 0, 255);
175	data->in[index][nr] = regval << 4;
176	reg = index == 1 ? ADC128_REG_IN_MIN(nr) : ADC128_REG_IN_MAX(nr);
177	i2c_smbus_write_byte_data(data->client, reg, regval);
178	mutex_unlock(&data->update_lock);
179
180	return count;
181}
182
183static ssize_t adc128_show_temp(struct device *dev,
184				struct device_attribute *attr, char *buf)
185{
186	struct adc128_data *data = adc128_update_device(dev);
187	int index = to_sensor_dev_attr(attr)->index;
188	int temp;
189
190	if (IS_ERR(data))
191		return PTR_ERR(data);
192
193	temp = sign_extend32(data->temp[index], 8);
194	return sprintf(buf, "%d\n", temp * 500);/* 0.5 degrees C resolution */
195}
196
197static ssize_t adc128_set_temp(struct device *dev,
198			       struct device_attribute *attr,
199			       const char *buf, size_t count)
200{
201	struct adc128_data *data = dev_get_drvdata(dev);
202	int index = to_sensor_dev_attr(attr)->index;
203	long val;
204	int err;
205	s8 regval;
206
207	err = kstrtol(buf, 10, &val);
208	if (err < 0)
209		return err;
210
211	mutex_lock(&data->update_lock);
212	regval = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
213	data->temp[index] = regval << 1;
214	i2c_smbus_write_byte_data(data->client,
215				  index == 1 ? ADC128_REG_TEMP_MAX
216					     : ADC128_REG_TEMP_HYST,
217				  regval);
218	mutex_unlock(&data->update_lock);
219
220	return count;
221}
222
223static ssize_t adc128_show_alarm(struct device *dev,
224				 struct device_attribute *attr, char *buf)
225{
226	struct adc128_data *data = adc128_update_device(dev);
227	int mask = 1 << to_sensor_dev_attr(attr)->index;
228	u8 alarms;
229
230	if (IS_ERR(data))
231		return PTR_ERR(data);
232
233	/*
234	 * Clear an alarm after reporting it to user space. If it is still
235	 * active, the next update sequence will set the alarm bit again.
236	 */
237	alarms = data->alarms;
238	data->alarms &= ~mask;
239
240	return sprintf(buf, "%u\n", !!(alarms & mask));
241}
242
243static SENSOR_DEVICE_ATTR_2(in0_input, S_IRUGO,
244			    adc128_show_in, NULL, 0, 0);
245static SENSOR_DEVICE_ATTR_2(in0_min, S_IWUSR | S_IRUGO,
246			    adc128_show_in, adc128_set_in, 0, 1);
247static SENSOR_DEVICE_ATTR_2(in0_max, S_IWUSR | S_IRUGO,
248			    adc128_show_in, adc128_set_in, 0, 2);
249
250static SENSOR_DEVICE_ATTR_2(in1_input, S_IRUGO,
251			    adc128_show_in, NULL, 1, 0);
252static SENSOR_DEVICE_ATTR_2(in1_min, S_IWUSR | S_IRUGO,
253			    adc128_show_in, adc128_set_in, 1, 1);
254static SENSOR_DEVICE_ATTR_2(in1_max, S_IWUSR | S_IRUGO,
255			    adc128_show_in, adc128_set_in, 1, 2);
256
257static SENSOR_DEVICE_ATTR_2(in2_input, S_IRUGO,
258			    adc128_show_in, NULL, 2, 0);
259static SENSOR_DEVICE_ATTR_2(in2_min, S_IWUSR | S_IRUGO,
260			    adc128_show_in, adc128_set_in, 2, 1);
261static SENSOR_DEVICE_ATTR_2(in2_max, S_IWUSR | S_IRUGO,
262			    adc128_show_in, adc128_set_in, 2, 2);
263
264static SENSOR_DEVICE_ATTR_2(in3_input, S_IRUGO,
265			    adc128_show_in, NULL, 3, 0);
266static SENSOR_DEVICE_ATTR_2(in3_min, S_IWUSR | S_IRUGO,
267			    adc128_show_in, adc128_set_in, 3, 1);
268static SENSOR_DEVICE_ATTR_2(in3_max, S_IWUSR | S_IRUGO,
269			    adc128_show_in, adc128_set_in, 3, 2);
270
271static SENSOR_DEVICE_ATTR_2(in4_input, S_IRUGO,
272			    adc128_show_in, NULL, 4, 0);
273static SENSOR_DEVICE_ATTR_2(in4_min, S_IWUSR | S_IRUGO,
274			    adc128_show_in, adc128_set_in, 4, 1);
275static SENSOR_DEVICE_ATTR_2(in4_max, S_IWUSR | S_IRUGO,
276			    adc128_show_in, adc128_set_in, 4, 2);
277
278static SENSOR_DEVICE_ATTR_2(in5_input, S_IRUGO,
279			    adc128_show_in, NULL, 5, 0);
280static SENSOR_DEVICE_ATTR_2(in5_min, S_IWUSR | S_IRUGO,
281			    adc128_show_in, adc128_set_in, 5, 1);
282static SENSOR_DEVICE_ATTR_2(in5_max, S_IWUSR | S_IRUGO,
283			    adc128_show_in, adc128_set_in, 5, 2);
284
285static SENSOR_DEVICE_ATTR_2(in6_input, S_IRUGO,
286			    adc128_show_in, NULL, 6, 0);
287static SENSOR_DEVICE_ATTR_2(in6_min, S_IWUSR | S_IRUGO,
288			    adc128_show_in, adc128_set_in, 6, 1);
289static SENSOR_DEVICE_ATTR_2(in6_max, S_IWUSR | S_IRUGO,
290			    adc128_show_in, adc128_set_in, 6, 2);
291
292static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adc128_show_temp, NULL, 0);
293static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
294			  adc128_show_temp, adc128_set_temp, 1);
295static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
296			  adc128_show_temp, adc128_set_temp, 2);
297
298static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, adc128_show_alarm, NULL, 0);
299static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, adc128_show_alarm, NULL, 1);
300static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, adc128_show_alarm, NULL, 2);
301static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, adc128_show_alarm, NULL, 3);
302static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, adc128_show_alarm, NULL, 4);
303static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, adc128_show_alarm, NULL, 5);
304static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, adc128_show_alarm, NULL, 6);
305static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adc128_show_alarm, NULL, 7);
306
307static struct attribute *adc128_attrs[] = {
308	&sensor_dev_attr_in0_min.dev_attr.attr,
309	&sensor_dev_attr_in1_min.dev_attr.attr,
310	&sensor_dev_attr_in2_min.dev_attr.attr,
311	&sensor_dev_attr_in3_min.dev_attr.attr,
312	&sensor_dev_attr_in4_min.dev_attr.attr,
313	&sensor_dev_attr_in5_min.dev_attr.attr,
314	&sensor_dev_attr_in6_min.dev_attr.attr,
315	&sensor_dev_attr_in0_max.dev_attr.attr,
316	&sensor_dev_attr_in1_max.dev_attr.attr,
317	&sensor_dev_attr_in2_max.dev_attr.attr,
318	&sensor_dev_attr_in3_max.dev_attr.attr,
319	&sensor_dev_attr_in4_max.dev_attr.attr,
320	&sensor_dev_attr_in5_max.dev_attr.attr,
321	&sensor_dev_attr_in6_max.dev_attr.attr,
322	&sensor_dev_attr_in0_input.dev_attr.attr,
323	&sensor_dev_attr_in1_input.dev_attr.attr,
324	&sensor_dev_attr_in2_input.dev_attr.attr,
325	&sensor_dev_attr_in3_input.dev_attr.attr,
326	&sensor_dev_attr_in4_input.dev_attr.attr,
327	&sensor_dev_attr_in5_input.dev_attr.attr,
328	&sensor_dev_attr_in6_input.dev_attr.attr,
329	&sensor_dev_attr_temp1_input.dev_attr.attr,
330	&sensor_dev_attr_temp1_max.dev_attr.attr,
331	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
332	&sensor_dev_attr_in0_alarm.dev_attr.attr,
333	&sensor_dev_attr_in1_alarm.dev_attr.attr,
334	&sensor_dev_attr_in2_alarm.dev_attr.attr,
335	&sensor_dev_attr_in3_alarm.dev_attr.attr,
336	&sensor_dev_attr_in4_alarm.dev_attr.attr,
337	&sensor_dev_attr_in5_alarm.dev_attr.attr,
338	&sensor_dev_attr_in6_alarm.dev_attr.attr,
339	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
340	NULL
341};
342ATTRIBUTE_GROUPS(adc128);
343
344static int adc128_detect(struct i2c_client *client, struct i2c_board_info *info)
345{
346	int man_id, dev_id;
347
348	if (!i2c_check_functionality(client->adapter,
349				     I2C_FUNC_SMBUS_BYTE_DATA |
350				     I2C_FUNC_SMBUS_WORD_DATA))
351		return -ENODEV;
352
353	man_id = i2c_smbus_read_byte_data(client, ADC128_REG_MAN_ID);
354	dev_id = i2c_smbus_read_byte_data(client, ADC128_REG_DEV_ID);
355	if (man_id != 0x01 || dev_id != 0x09)
356		return -ENODEV;
357
358	/* Check unused bits for confirmation */
359	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG) & 0xf4)
360		return -ENODEV;
361	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONV_RATE) & 0xfe)
362		return -ENODEV;
363	if (i2c_smbus_read_byte_data(client, ADC128_REG_ONESHOT) & 0xfe)
364		return -ENODEV;
365	if (i2c_smbus_read_byte_data(client, ADC128_REG_SHUTDOWN) & 0xfe)
366		return -ENODEV;
367	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV) & 0xf8)
368		return -ENODEV;
369	if (i2c_smbus_read_byte_data(client, ADC128_REG_BUSY_STATUS) & 0xfc)
370		return -ENODEV;
371
372	strlcpy(info->type, "adc128d818", I2C_NAME_SIZE);
373
374	return 0;
375}
376
377static int adc128_init_client(struct adc128_data *data)
378{
379	struct i2c_client *client = data->client;
380	int err;
381
382	/*
383	 * Reset chip to defaults.
384	 * This makes most other initializations unnecessary.
385	 */
386	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x80);
387	if (err)
388		return err;
389
390	/* Start monitoring */
391	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x01);
392	if (err)
393		return err;
394
395	/* If external vref is selected, configure the chip to use it */
396	if (data->regulator) {
397		err = i2c_smbus_write_byte_data(client,
398						ADC128_REG_CONFIG_ADV, 0x01);
399		if (err)
400			return err;
401	}
402
403	return 0;
404}
405
406static int adc128_probe(struct i2c_client *client,
407			const struct i2c_device_id *id)
408{
409	struct device *dev = &client->dev;
410	struct regulator *regulator;
411	struct device *hwmon_dev;
412	struct adc128_data *data;
413	int err, vref;
414
415	data = devm_kzalloc(dev, sizeof(struct adc128_data), GFP_KERNEL);
416	if (!data)
417		return -ENOMEM;
418
419	/* vref is optional. If specified, is used as chip reference voltage */
420	regulator = devm_regulator_get_optional(dev, "vref");
421	if (!IS_ERR(regulator)) {
422		data->regulator = regulator;
423		err = regulator_enable(regulator);
424		if (err < 0)
425			return err;
426		vref = regulator_get_voltage(regulator);
427		if (vref < 0) {
428			err = vref;
429			goto error;
430		}
431		data->vref = DIV_ROUND_CLOSEST(vref, 1000);
432	} else {
433		data->vref = 2560;	/* 2.56V, in mV */
434	}
435
436	data->client = client;
437	i2c_set_clientdata(client, data);
438	mutex_init(&data->update_lock);
439
440	/* Initialize the chip */
441	err = adc128_init_client(data);
442	if (err < 0)
443		goto error;
444
445	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
446							   data, adc128_groups);
447	if (IS_ERR(hwmon_dev)) {
448		err = PTR_ERR(hwmon_dev);
449		goto error;
450	}
451
452	return 0;
453
454error:
455	if (data->regulator)
456		regulator_disable(data->regulator);
457	return err;
458}
459
460static int adc128_remove(struct i2c_client *client)
461{
462	struct adc128_data *data = i2c_get_clientdata(client);
463
464	if (data->regulator)
465		regulator_disable(data->regulator);
466
467	return 0;
468}
469
470static const struct i2c_device_id adc128_id[] = {
471	{ "adc128d818", 0 },
472	{ }
473};
474MODULE_DEVICE_TABLE(i2c, adc128_id);
475
476static struct i2c_driver adc128_driver = {
477	.class		= I2C_CLASS_HWMON,
478	.driver = {
479		.name	= "adc128d818",
480	},
481	.probe		= adc128_probe,
482	.remove		= adc128_remove,
483	.id_table	= adc128_id,
484	.detect		= adc128_detect,
485	.address_list	= normal_i2c,
486};
487
488module_i2c_driver(adc128_driver);
489
490MODULE_AUTHOR("Guenter Roeck");
491MODULE_DESCRIPTION("Driver for ADC128D818");
492MODULE_LICENSE("GPL");
493