xref: /openbmc/linux/drivers/hwmon/adc128d818.c (revision afb46f79)
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 
31 /* Addresses to scan
32  * The chip also supports addresses 0x35..0x37. Don't scan those addresses
33  * since they are also used by some EEPROMs, which may result in false
34  * positives.
35  */
36 static const unsigned short normal_i2c[] = {
37 	0x1d, 0x1e, 0x1f, 0x2d, 0x2e, 0x2f, I2C_CLIENT_END };
38 
39 /* registers */
40 #define ADC128_REG_IN_MAX(nr)		(0x2a + (nr) * 2)
41 #define ADC128_REG_IN_MIN(nr)		(0x2b + (nr) * 2)
42 #define ADC128_REG_IN(nr)		(0x20 + (nr))
43 
44 #define ADC128_REG_TEMP			0x27
45 #define ADC128_REG_TEMP_MAX		0x38
46 #define ADC128_REG_TEMP_HYST		0x39
47 
48 #define ADC128_REG_CONFIG		0x00
49 #define ADC128_REG_ALARM		0x01
50 #define ADC128_REG_MASK			0x03
51 #define ADC128_REG_CONV_RATE		0x07
52 #define ADC128_REG_ONESHOT		0x09
53 #define ADC128_REG_SHUTDOWN		0x0a
54 #define ADC128_REG_CONFIG_ADV		0x0b
55 #define ADC128_REG_BUSY_STATUS		0x0c
56 
57 #define ADC128_REG_MAN_ID		0x3e
58 #define ADC128_REG_DEV_ID		0x3f
59 
60 struct adc128_data {
61 	struct i2c_client *client;
62 	struct regulator *regulator;
63 	int vref;		/* Reference voltage in mV */
64 	struct mutex update_lock;
65 	bool valid;		/* true if following fields are valid */
66 	unsigned long last_updated;	/* In jiffies */
67 
68 	u16 in[3][7];		/* Register value, normalized to 12 bit
69 				 * 0: input voltage
70 				 * 1: min limit
71 				 * 2: max limit
72 				 */
73 	s16 temp[3];		/* Register value, normalized to 9 bit
74 				 * 0: sensor 1: limit 2: hyst
75 				 */
76 	u8 alarms;		/* alarm register value */
77 };
78 
79 static struct adc128_data *adc128_update_device(struct device *dev)
80 {
81 	struct adc128_data *data = dev_get_drvdata(dev);
82 	struct i2c_client *client = data->client;
83 	struct adc128_data *ret = data;
84 	int i, rv;
85 
86 	mutex_lock(&data->update_lock);
87 
88 	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
89 		for (i = 0; i < 7; i++) {
90 			rv = i2c_smbus_read_word_swapped(client,
91 							 ADC128_REG_IN(i));
92 			if (rv < 0)
93 				goto abort;
94 			data->in[0][i] = rv >> 4;
95 
96 			rv = i2c_smbus_read_byte_data(client,
97 						      ADC128_REG_IN_MIN(i));
98 			if (rv < 0)
99 				goto abort;
100 			data->in[1][i] = rv << 4;
101 
102 			rv = i2c_smbus_read_byte_data(client,
103 						      ADC128_REG_IN_MAX(i));
104 			if (rv < 0)
105 				goto abort;
106 			data->in[2][i] = rv << 4;
107 		}
108 
109 		rv = i2c_smbus_read_word_swapped(client, ADC128_REG_TEMP);
110 		if (rv < 0)
111 			goto abort;
112 		data->temp[0] = rv >> 7;
113 
114 		rv = i2c_smbus_read_byte_data(client, ADC128_REG_TEMP_MAX);
115 		if (rv < 0)
116 			goto abort;
117 		data->temp[1] = rv << 1;
118 
119 		rv = i2c_smbus_read_byte_data(client, ADC128_REG_TEMP_HYST);
120 		if (rv < 0)
121 			goto abort;
122 		data->temp[2] = rv << 1;
123 
124 		rv = i2c_smbus_read_byte_data(client, ADC128_REG_ALARM);
125 		if (rv < 0)
126 			goto abort;
127 		data->alarms |= rv;
128 
129 		data->last_updated = jiffies;
130 		data->valid = true;
131 	}
132 	goto done;
133 
134 abort:
135 	ret = ERR_PTR(rv);
136 	data->valid = false;
137 done:
138 	mutex_unlock(&data->update_lock);
139 	return ret;
140 }
141 
142 static ssize_t adc128_show_in(struct device *dev, struct device_attribute *attr,
143 			      char *buf)
144 {
145 	struct adc128_data *data = adc128_update_device(dev);
146 	int index = to_sensor_dev_attr_2(attr)->index;
147 	int nr = to_sensor_dev_attr_2(attr)->nr;
148 	int val;
149 
150 	if (IS_ERR(data))
151 		return PTR_ERR(data);
152 
153 	val = DIV_ROUND_CLOSEST(data->in[index][nr] * data->vref, 4095);
154 	return sprintf(buf, "%d\n", val);
155 }
156 
157 static ssize_t adc128_set_in(struct device *dev, struct device_attribute *attr,
158 			     const char *buf, size_t count)
159 {
160 	struct adc128_data *data = dev_get_drvdata(dev);
161 	int index = to_sensor_dev_attr_2(attr)->index;
162 	int nr = to_sensor_dev_attr_2(attr)->nr;
163 	u8 reg, regval;
164 	long val;
165 	int err;
166 
167 	err = kstrtol(buf, 10, &val);
168 	if (err < 0)
169 		return err;
170 
171 	mutex_lock(&data->update_lock);
172 	/* 10 mV LSB on limit registers */
173 	regval = clamp_val(DIV_ROUND_CLOSEST(val, 10), 0, 255);
174 	data->in[index][nr] = regval << 4;
175 	reg = index == 1 ? ADC128_REG_IN_MIN(nr) : ADC128_REG_IN_MAX(nr);
176 	i2c_smbus_write_byte_data(data->client, reg, regval);
177 	mutex_unlock(&data->update_lock);
178 
179 	return count;
180 }
181 
182 static ssize_t adc128_show_temp(struct device *dev,
183 				struct device_attribute *attr, char *buf)
184 {
185 	struct adc128_data *data = adc128_update_device(dev);
186 	int index = to_sensor_dev_attr(attr)->index;
187 	int temp;
188 
189 	if (IS_ERR(data))
190 		return PTR_ERR(data);
191 
192 	temp = (data->temp[index] << 7) >> 7;	/* sign extend */
193 	return sprintf(buf, "%d\n", temp * 500);/* 0.5 degrees C resolution */
194 }
195 
196 static ssize_t adc128_set_temp(struct device *dev,
197 			       struct device_attribute *attr,
198 			       const char *buf, size_t count)
199 {
200 	struct adc128_data *data = dev_get_drvdata(dev);
201 	int index = to_sensor_dev_attr(attr)->index;
202 	long val;
203 	int err;
204 	s8 regval;
205 
206 	err = kstrtol(buf, 10, &val);
207 	if (err < 0)
208 		return err;
209 
210 	mutex_lock(&data->update_lock);
211 	regval = clamp_val(DIV_ROUND_CLOSEST(val, 1000), -128, 127);
212 	data->temp[index] = regval << 1;
213 	i2c_smbus_write_byte_data(data->client,
214 				  index == 1 ? ADC128_REG_TEMP_MAX
215 					     : ADC128_REG_TEMP_HYST,
216 				  regval);
217 	mutex_unlock(&data->update_lock);
218 
219 	return count;
220 }
221 
222 static ssize_t adc128_show_alarm(struct device *dev,
223 				 struct device_attribute *attr, char *buf)
224 {
225 	struct adc128_data *data = adc128_update_device(dev);
226 	int mask = 1 << to_sensor_dev_attr(attr)->index;
227 	u8 alarms;
228 
229 	if (IS_ERR(data))
230 		return PTR_ERR(data);
231 
232 	/*
233 	 * Clear an alarm after reporting it to user space. If it is still
234 	 * active, the next update sequence will set the alarm bit again.
235 	 */
236 	alarms = data->alarms;
237 	data->alarms &= ~mask;
238 
239 	return sprintf(buf, "%u\n", !!(alarms & mask));
240 }
241 
242 static SENSOR_DEVICE_ATTR_2(in0_input, S_IWUSR | S_IRUGO,
243 			    adc128_show_in, adc128_set_in, 0, 0);
244 static SENSOR_DEVICE_ATTR_2(in0_min, S_IWUSR | S_IRUGO,
245 			    adc128_show_in, adc128_set_in, 0, 1);
246 static SENSOR_DEVICE_ATTR_2(in0_max, S_IWUSR | S_IRUGO,
247 			    adc128_show_in, adc128_set_in, 0, 2);
248 
249 static SENSOR_DEVICE_ATTR_2(in1_input, S_IWUSR | S_IRUGO,
250 			    adc128_show_in, adc128_set_in, 1, 0);
251 static SENSOR_DEVICE_ATTR_2(in1_min, S_IWUSR | S_IRUGO,
252 			    adc128_show_in, adc128_set_in, 1, 1);
253 static SENSOR_DEVICE_ATTR_2(in1_max, S_IWUSR | S_IRUGO,
254 			    adc128_show_in, adc128_set_in, 1, 2);
255 
256 static SENSOR_DEVICE_ATTR_2(in2_input, S_IWUSR | S_IRUGO,
257 			    adc128_show_in, adc128_set_in, 2, 0);
258 static SENSOR_DEVICE_ATTR_2(in2_min, S_IWUSR | S_IRUGO,
259 			    adc128_show_in, adc128_set_in, 2, 1);
260 static SENSOR_DEVICE_ATTR_2(in2_max, S_IWUSR | S_IRUGO,
261 			    adc128_show_in, adc128_set_in, 2, 2);
262 
263 static SENSOR_DEVICE_ATTR_2(in3_input, S_IWUSR | S_IRUGO,
264 			    adc128_show_in, adc128_set_in, 3, 0);
265 static SENSOR_DEVICE_ATTR_2(in3_min, S_IWUSR | S_IRUGO,
266 			    adc128_show_in, adc128_set_in, 3, 1);
267 static SENSOR_DEVICE_ATTR_2(in3_max, S_IWUSR | S_IRUGO,
268 			    adc128_show_in, adc128_set_in, 3, 2);
269 
270 static SENSOR_DEVICE_ATTR_2(in4_input, S_IWUSR | S_IRUGO,
271 			    adc128_show_in, adc128_set_in, 4, 0);
272 static SENSOR_DEVICE_ATTR_2(in4_min, S_IWUSR | S_IRUGO,
273 			    adc128_show_in, adc128_set_in, 4, 1);
274 static SENSOR_DEVICE_ATTR_2(in4_max, S_IWUSR | S_IRUGO,
275 			    adc128_show_in, adc128_set_in, 4, 2);
276 
277 static SENSOR_DEVICE_ATTR_2(in5_input, S_IWUSR | S_IRUGO,
278 			    adc128_show_in, adc128_set_in, 5, 0);
279 static SENSOR_DEVICE_ATTR_2(in5_min, S_IWUSR | S_IRUGO,
280 			    adc128_show_in, adc128_set_in, 5, 1);
281 static SENSOR_DEVICE_ATTR_2(in5_max, S_IWUSR | S_IRUGO,
282 			    adc128_show_in, adc128_set_in, 5, 2);
283 
284 static SENSOR_DEVICE_ATTR_2(in6_input, S_IWUSR | S_IRUGO,
285 			    adc128_show_in, adc128_set_in, 6, 0);
286 static SENSOR_DEVICE_ATTR_2(in6_min, S_IWUSR | S_IRUGO,
287 			    adc128_show_in, adc128_set_in, 6, 1);
288 static SENSOR_DEVICE_ATTR_2(in6_max, S_IWUSR | S_IRUGO,
289 			    adc128_show_in, adc128_set_in, 6, 2);
290 
291 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, adc128_show_temp, NULL, 0);
292 static SENSOR_DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
293 			  adc128_show_temp, adc128_set_temp, 1);
294 static SENSOR_DEVICE_ATTR(temp1_max_hyst, S_IWUSR | S_IRUGO,
295 			  adc128_show_temp, adc128_set_temp, 2);
296 
297 static SENSOR_DEVICE_ATTR(in0_alarm, S_IRUGO, adc128_show_alarm, NULL, 0);
298 static SENSOR_DEVICE_ATTR(in1_alarm, S_IRUGO, adc128_show_alarm, NULL, 1);
299 static SENSOR_DEVICE_ATTR(in2_alarm, S_IRUGO, adc128_show_alarm, NULL, 2);
300 static SENSOR_DEVICE_ATTR(in3_alarm, S_IRUGO, adc128_show_alarm, NULL, 3);
301 static SENSOR_DEVICE_ATTR(in4_alarm, S_IRUGO, adc128_show_alarm, NULL, 4);
302 static SENSOR_DEVICE_ATTR(in5_alarm, S_IRUGO, adc128_show_alarm, NULL, 5);
303 static SENSOR_DEVICE_ATTR(in6_alarm, S_IRUGO, adc128_show_alarm, NULL, 6);
304 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, adc128_show_alarm, NULL, 7);
305 
306 static struct attribute *adc128_attrs[] = {
307 	&sensor_dev_attr_in0_min.dev_attr.attr,
308 	&sensor_dev_attr_in1_min.dev_attr.attr,
309 	&sensor_dev_attr_in2_min.dev_attr.attr,
310 	&sensor_dev_attr_in3_min.dev_attr.attr,
311 	&sensor_dev_attr_in4_min.dev_attr.attr,
312 	&sensor_dev_attr_in5_min.dev_attr.attr,
313 	&sensor_dev_attr_in6_min.dev_attr.attr,
314 	&sensor_dev_attr_in0_max.dev_attr.attr,
315 	&sensor_dev_attr_in1_max.dev_attr.attr,
316 	&sensor_dev_attr_in2_max.dev_attr.attr,
317 	&sensor_dev_attr_in3_max.dev_attr.attr,
318 	&sensor_dev_attr_in4_max.dev_attr.attr,
319 	&sensor_dev_attr_in5_max.dev_attr.attr,
320 	&sensor_dev_attr_in6_max.dev_attr.attr,
321 	&sensor_dev_attr_in0_input.dev_attr.attr,
322 	&sensor_dev_attr_in1_input.dev_attr.attr,
323 	&sensor_dev_attr_in2_input.dev_attr.attr,
324 	&sensor_dev_attr_in3_input.dev_attr.attr,
325 	&sensor_dev_attr_in4_input.dev_attr.attr,
326 	&sensor_dev_attr_in5_input.dev_attr.attr,
327 	&sensor_dev_attr_in6_input.dev_attr.attr,
328 	&sensor_dev_attr_temp1_input.dev_attr.attr,
329 	&sensor_dev_attr_temp1_max.dev_attr.attr,
330 	&sensor_dev_attr_temp1_max_hyst.dev_attr.attr,
331 	&sensor_dev_attr_in0_alarm.dev_attr.attr,
332 	&sensor_dev_attr_in1_alarm.dev_attr.attr,
333 	&sensor_dev_attr_in2_alarm.dev_attr.attr,
334 	&sensor_dev_attr_in3_alarm.dev_attr.attr,
335 	&sensor_dev_attr_in4_alarm.dev_attr.attr,
336 	&sensor_dev_attr_in5_alarm.dev_attr.attr,
337 	&sensor_dev_attr_in6_alarm.dev_attr.attr,
338 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
339 	NULL
340 };
341 ATTRIBUTE_GROUPS(adc128);
342 
343 static int adc128_detect(struct i2c_client *client, struct i2c_board_info *info)
344 {
345 	int man_id, dev_id;
346 
347 	if (!i2c_check_functionality(client->adapter,
348 				     I2C_FUNC_SMBUS_BYTE_DATA |
349 				     I2C_FUNC_SMBUS_WORD_DATA))
350 		return -ENODEV;
351 
352 	man_id = i2c_smbus_read_byte_data(client, ADC128_REG_MAN_ID);
353 	dev_id = i2c_smbus_read_byte_data(client, ADC128_REG_DEV_ID);
354 	if (man_id != 0x01 || dev_id != 0x09)
355 		return -ENODEV;
356 
357 	/* Check unused bits for confirmation */
358 	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG) & 0xf4)
359 		return -ENODEV;
360 	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONV_RATE) & 0xfe)
361 		return -ENODEV;
362 	if (i2c_smbus_read_byte_data(client, ADC128_REG_ONESHOT) & 0xfe)
363 		return -ENODEV;
364 	if (i2c_smbus_read_byte_data(client, ADC128_REG_SHUTDOWN) & 0xfe)
365 		return -ENODEV;
366 	if (i2c_smbus_read_byte_data(client, ADC128_REG_CONFIG_ADV) & 0xf8)
367 		return -ENODEV;
368 	if (i2c_smbus_read_byte_data(client, ADC128_REG_BUSY_STATUS) & 0xfc)
369 		return -ENODEV;
370 
371 	strlcpy(info->type, "adc128d818", I2C_NAME_SIZE);
372 
373 	return 0;
374 }
375 
376 static int adc128_init_client(struct adc128_data *data)
377 {
378 	struct i2c_client *client = data->client;
379 	int err;
380 
381 	/*
382 	 * Reset chip to defaults.
383 	 * This makes most other initializations unnecessary.
384 	 */
385 	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x80);
386 	if (err)
387 		return err;
388 
389 	/* Start monitoring */
390 	err = i2c_smbus_write_byte_data(client, ADC128_REG_CONFIG, 0x01);
391 	if (err)
392 		return err;
393 
394 	/* If external vref is selected, configure the chip to use it */
395 	if (data->regulator) {
396 		err = i2c_smbus_write_byte_data(client,
397 						ADC128_REG_CONFIG_ADV, 0x01);
398 		if (err)
399 			return err;
400 	}
401 
402 	return 0;
403 }
404 
405 static int adc128_probe(struct i2c_client *client,
406 			const struct i2c_device_id *id)
407 {
408 	struct device *dev = &client->dev;
409 	struct regulator *regulator;
410 	struct device *hwmon_dev;
411 	struct adc128_data *data;
412 	int err, vref;
413 
414 	data = devm_kzalloc(dev, sizeof(struct adc128_data), GFP_KERNEL);
415 	if (!data)
416 		return -ENOMEM;
417 
418 	/* vref is optional. If specified, is used as chip reference voltage */
419 	regulator = devm_regulator_get_optional(dev, "vref");
420 	if (!IS_ERR(regulator)) {
421 		data->regulator = regulator;
422 		err = regulator_enable(regulator);
423 		if (err < 0)
424 			return err;
425 		vref = regulator_get_voltage(regulator);
426 		if (vref < 0) {
427 			err = vref;
428 			goto error;
429 		}
430 		data->vref = DIV_ROUND_CLOSEST(vref, 1000);
431 	} else {
432 		data->vref = 2560;	/* 2.56V, in mV */
433 	}
434 
435 	data->client = client;
436 	i2c_set_clientdata(client, data);
437 	mutex_init(&data->update_lock);
438 
439 	/* Initialize the chip */
440 	err = adc128_init_client(data);
441 	if (err < 0)
442 		goto error;
443 
444 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
445 							   data, adc128_groups);
446 	if (IS_ERR(hwmon_dev)) {
447 		err = PTR_ERR(hwmon_dev);
448 		goto error;
449 	}
450 
451 	return 0;
452 
453 error:
454 	if (data->regulator)
455 		regulator_disable(data->regulator);
456 	return err;
457 }
458 
459 static int adc128_remove(struct i2c_client *client)
460 {
461 	struct adc128_data *data = i2c_get_clientdata(client);
462 
463 	if (data->regulator)
464 		regulator_disable(data->regulator);
465 
466 	return 0;
467 }
468 
469 static const struct i2c_device_id adc128_id[] = {
470 	{ "adc128d818", 0 },
471 	{ }
472 };
473 MODULE_DEVICE_TABLE(i2c, adc128_id);
474 
475 static struct i2c_driver adc128_driver = {
476 	.class		= I2C_CLASS_HWMON,
477 	.driver = {
478 		.name	= "adc128d818",
479 	},
480 	.probe		= adc128_probe,
481 	.remove		= adc128_remove,
482 	.id_table	= adc128_id,
483 	.detect		= adc128_detect,
484 	.address_list	= normal_i2c,
485 };
486 
487 module_i2c_driver(adc128_driver);
488 
489 MODULE_AUTHOR("Guenter Roeck");
490 MODULE_DESCRIPTION("Driver for ADC128D818");
491 MODULE_LICENSE("GPL");
492