xref: /linux/drivers/hwmon/max1668.c (revision 3839a7460721b87501134697b7b90c45dcc7825d)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (c) 2011 David George <david.george@ska.ac.za>
4  *
5  * based on adm1021.c
6  * some credit to Christoph Scheurer, but largely a rewrite
7  */
8 
9 #include <linux/module.h>
10 #include <linux/init.h>
11 #include <linux/slab.h>
12 #include <linux/jiffies.h>
13 #include <linux/i2c.h>
14 #include <linux/hwmon.h>
15 #include <linux/hwmon-sysfs.h>
16 #include <linux/err.h>
17 #include <linux/mutex.h>
18 
19 /* Addresses to scan */
20 static const unsigned short max1668_addr_list[] = {
21 	0x18, 0x19, 0x1a, 0x29, 0x2a, 0x2b, 0x4c, 0x4d, 0x4e, I2C_CLIENT_END };
22 
23 /* max1668 registers */
24 
25 #define MAX1668_REG_TEMP(nr)	(nr)
26 #define MAX1668_REG_STAT1	0x05
27 #define MAX1668_REG_STAT2	0x06
28 #define MAX1668_REG_MAN_ID	0xfe
29 #define MAX1668_REG_DEV_ID	0xff
30 
31 /* limits */
32 
33 /* write high limits */
34 #define MAX1668_REG_LIMH_WR(nr)	(0x13 + 2 * (nr))
35 /* write low limits */
36 #define MAX1668_REG_LIML_WR(nr)	(0x14 + 2 * (nr))
37 /* read high limits */
38 #define MAX1668_REG_LIMH_RD(nr)	(0x08 + 2 * (nr))
39 /* read low limits */
40 #define MAX1668_REG_LIML_RD(nr)	(0x09 + 2 * (nr))
41 
42 /* manufacturer and device ID Constants */
43 #define MAN_ID_MAXIM		0x4d
44 #define DEV_ID_MAX1668		0x3
45 #define DEV_ID_MAX1805		0x5
46 #define DEV_ID_MAX1989		0xb
47 
48 /* read only mode module parameter */
49 static bool read_only;
50 module_param(read_only, bool, 0);
51 MODULE_PARM_DESC(read_only, "Don't set any values, read only mode");
52 
53 enum chips { max1668, max1805, max1989 };
54 
55 struct max1668_data {
56 	struct i2c_client *client;
57 	const struct attribute_group *groups[3];
58 	enum chips type;
59 
60 	struct mutex update_lock;
61 	char valid;		/* !=0 if following fields are valid */
62 	unsigned long last_updated;	/* In jiffies */
63 
64 	/* 1x local and 4x remote */
65 	s8 temp_max[5];
66 	s8 temp_min[5];
67 	s8 temp[5];
68 	u16 alarms;
69 };
70 
71 static struct max1668_data *max1668_update_device(struct device *dev)
72 {
73 	struct max1668_data *data = dev_get_drvdata(dev);
74 	struct i2c_client *client = data->client;
75 	struct max1668_data *ret = data;
76 	s32 val;
77 	int i;
78 
79 	mutex_lock(&data->update_lock);
80 
81 	if (data->valid && !time_after(jiffies,
82 			data->last_updated + HZ + HZ / 2))
83 		goto abort;
84 
85 	for (i = 0; i < 5; i++) {
86 		val = i2c_smbus_read_byte_data(client, MAX1668_REG_TEMP(i));
87 		if (unlikely(val < 0)) {
88 			ret = ERR_PTR(val);
89 			goto abort;
90 		}
91 		data->temp[i] = (s8) val;
92 
93 		val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIMH_RD(i));
94 		if (unlikely(val < 0)) {
95 			ret = ERR_PTR(val);
96 			goto abort;
97 		}
98 		data->temp_max[i] = (s8) val;
99 
100 		val = i2c_smbus_read_byte_data(client, MAX1668_REG_LIML_RD(i));
101 		if (unlikely(val < 0)) {
102 			ret = ERR_PTR(val);
103 			goto abort;
104 		}
105 		data->temp_min[i] = (s8) val;
106 	}
107 
108 	val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT1);
109 	if (unlikely(val < 0)) {
110 		ret = ERR_PTR(val);
111 		goto abort;
112 	}
113 	data->alarms = val << 8;
114 
115 	val = i2c_smbus_read_byte_data(client, MAX1668_REG_STAT2);
116 	if (unlikely(val < 0)) {
117 		ret = ERR_PTR(val);
118 		goto abort;
119 	}
120 	data->alarms |= val;
121 
122 	data->last_updated = jiffies;
123 	data->valid = 1;
124 abort:
125 	mutex_unlock(&data->update_lock);
126 
127 	return ret;
128 }
129 
130 static ssize_t show_temp(struct device *dev,
131 			 struct device_attribute *devattr, char *buf)
132 {
133 	int index = to_sensor_dev_attr(devattr)->index;
134 	struct max1668_data *data = max1668_update_device(dev);
135 
136 	if (IS_ERR(data))
137 		return PTR_ERR(data);
138 
139 	return sprintf(buf, "%d\n", data->temp[index] * 1000);
140 }
141 
142 static ssize_t show_temp_max(struct device *dev,
143 			     struct device_attribute *devattr, char *buf)
144 {
145 	int index = to_sensor_dev_attr(devattr)->index;
146 	struct max1668_data *data = max1668_update_device(dev);
147 
148 	if (IS_ERR(data))
149 		return PTR_ERR(data);
150 
151 	return sprintf(buf, "%d\n", data->temp_max[index] * 1000);
152 }
153 
154 static ssize_t show_temp_min(struct device *dev,
155 			     struct device_attribute *devattr, char *buf)
156 {
157 	int index = to_sensor_dev_attr(devattr)->index;
158 	struct max1668_data *data = max1668_update_device(dev);
159 
160 	if (IS_ERR(data))
161 		return PTR_ERR(data);
162 
163 	return sprintf(buf, "%d\n", data->temp_min[index] * 1000);
164 }
165 
166 static ssize_t show_alarm(struct device *dev, struct device_attribute *attr,
167 			  char *buf)
168 {
169 	int index = to_sensor_dev_attr(attr)->index;
170 	struct max1668_data *data = max1668_update_device(dev);
171 
172 	if (IS_ERR(data))
173 		return PTR_ERR(data);
174 
175 	return sprintf(buf, "%u\n", (data->alarms >> index) & 0x1);
176 }
177 
178 static ssize_t show_fault(struct device *dev,
179 			  struct device_attribute *devattr, char *buf)
180 {
181 	int index = to_sensor_dev_attr(devattr)->index;
182 	struct max1668_data *data = max1668_update_device(dev);
183 
184 	if (IS_ERR(data))
185 		return PTR_ERR(data);
186 
187 	return sprintf(buf, "%u\n",
188 		       (data->alarms & (1 << 12)) && data->temp[index] == 127);
189 }
190 
191 static ssize_t set_temp_max(struct device *dev,
192 			    struct device_attribute *devattr,
193 			    const char *buf, size_t count)
194 {
195 	int index = to_sensor_dev_attr(devattr)->index;
196 	struct max1668_data *data = dev_get_drvdata(dev);
197 	struct i2c_client *client = data->client;
198 	long temp;
199 	int ret;
200 
201 	ret = kstrtol(buf, 10, &temp);
202 	if (ret < 0)
203 		return ret;
204 
205 	mutex_lock(&data->update_lock);
206 	data->temp_max[index] = clamp_val(temp/1000, -128, 127);
207 	ret = i2c_smbus_write_byte_data(client,
208 					MAX1668_REG_LIMH_WR(index),
209 					data->temp_max[index]);
210 	if (ret < 0)
211 		count = ret;
212 	mutex_unlock(&data->update_lock);
213 
214 	return count;
215 }
216 
217 static ssize_t set_temp_min(struct device *dev,
218 			    struct device_attribute *devattr,
219 			    const char *buf, size_t count)
220 {
221 	int index = to_sensor_dev_attr(devattr)->index;
222 	struct max1668_data *data = dev_get_drvdata(dev);
223 	struct i2c_client *client = data->client;
224 	long temp;
225 	int ret;
226 
227 	ret = kstrtol(buf, 10, &temp);
228 	if (ret < 0)
229 		return ret;
230 
231 	mutex_lock(&data->update_lock);
232 	data->temp_min[index] = clamp_val(temp/1000, -128, 127);
233 	ret = i2c_smbus_write_byte_data(client,
234 					MAX1668_REG_LIML_WR(index),
235 					data->temp_min[index]);
236 	if (ret < 0)
237 		count = ret;
238 	mutex_unlock(&data->update_lock);
239 
240 	return count;
241 }
242 
243 static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, show_temp, NULL, 0);
244 static SENSOR_DEVICE_ATTR(temp1_max, S_IRUGO, show_temp_max,
245 				set_temp_max, 0);
246 static SENSOR_DEVICE_ATTR(temp1_min, S_IRUGO, show_temp_min,
247 				set_temp_min, 0);
248 static SENSOR_DEVICE_ATTR(temp2_input, S_IRUGO, show_temp, NULL, 1);
249 static SENSOR_DEVICE_ATTR(temp2_max, S_IRUGO, show_temp_max,
250 				set_temp_max, 1);
251 static SENSOR_DEVICE_ATTR(temp2_min, S_IRUGO, show_temp_min,
252 				set_temp_min, 1);
253 static SENSOR_DEVICE_ATTR(temp3_input, S_IRUGO, show_temp, NULL, 2);
254 static SENSOR_DEVICE_ATTR(temp3_max, S_IRUGO, show_temp_max,
255 				set_temp_max, 2);
256 static SENSOR_DEVICE_ATTR(temp3_min, S_IRUGO, show_temp_min,
257 				set_temp_min, 2);
258 static SENSOR_DEVICE_ATTR(temp4_input, S_IRUGO, show_temp, NULL, 3);
259 static SENSOR_DEVICE_ATTR(temp4_max, S_IRUGO, show_temp_max,
260 				set_temp_max, 3);
261 static SENSOR_DEVICE_ATTR(temp4_min, S_IRUGO, show_temp_min,
262 				set_temp_min, 3);
263 static SENSOR_DEVICE_ATTR(temp5_input, S_IRUGO, show_temp, NULL, 4);
264 static SENSOR_DEVICE_ATTR(temp5_max, S_IRUGO, show_temp_max,
265 				set_temp_max, 4);
266 static SENSOR_DEVICE_ATTR(temp5_min, S_IRUGO, show_temp_min,
267 				set_temp_min, 4);
268 
269 static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL, 14);
270 static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL, 13);
271 static SENSOR_DEVICE_ATTR(temp2_min_alarm, S_IRUGO, show_alarm, NULL, 7);
272 static SENSOR_DEVICE_ATTR(temp2_max_alarm, S_IRUGO, show_alarm, NULL, 6);
273 static SENSOR_DEVICE_ATTR(temp3_min_alarm, S_IRUGO, show_alarm, NULL, 5);
274 static SENSOR_DEVICE_ATTR(temp3_max_alarm, S_IRUGO, show_alarm, NULL, 4);
275 static SENSOR_DEVICE_ATTR(temp4_min_alarm, S_IRUGO, show_alarm, NULL, 3);
276 static SENSOR_DEVICE_ATTR(temp4_max_alarm, S_IRUGO, show_alarm, NULL, 2);
277 static SENSOR_DEVICE_ATTR(temp5_min_alarm, S_IRUGO, show_alarm, NULL, 1);
278 static SENSOR_DEVICE_ATTR(temp5_max_alarm, S_IRUGO, show_alarm, NULL, 0);
279 
280 static SENSOR_DEVICE_ATTR(temp2_fault, S_IRUGO, show_fault, NULL, 1);
281 static SENSOR_DEVICE_ATTR(temp3_fault, S_IRUGO, show_fault, NULL, 2);
282 static SENSOR_DEVICE_ATTR(temp4_fault, S_IRUGO, show_fault, NULL, 3);
283 static SENSOR_DEVICE_ATTR(temp5_fault, S_IRUGO, show_fault, NULL, 4);
284 
285 /* Attributes common to MAX1668, MAX1989 and MAX1805 */
286 static struct attribute *max1668_attribute_common[] = {
287 	&sensor_dev_attr_temp1_max.dev_attr.attr,
288 	&sensor_dev_attr_temp1_min.dev_attr.attr,
289 	&sensor_dev_attr_temp1_input.dev_attr.attr,
290 	&sensor_dev_attr_temp2_max.dev_attr.attr,
291 	&sensor_dev_attr_temp2_min.dev_attr.attr,
292 	&sensor_dev_attr_temp2_input.dev_attr.attr,
293 	&sensor_dev_attr_temp3_max.dev_attr.attr,
294 	&sensor_dev_attr_temp3_min.dev_attr.attr,
295 	&sensor_dev_attr_temp3_input.dev_attr.attr,
296 
297 	&sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
298 	&sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
299 	&sensor_dev_attr_temp2_max_alarm.dev_attr.attr,
300 	&sensor_dev_attr_temp2_min_alarm.dev_attr.attr,
301 	&sensor_dev_attr_temp3_max_alarm.dev_attr.attr,
302 	&sensor_dev_attr_temp3_min_alarm.dev_attr.attr,
303 
304 	&sensor_dev_attr_temp2_fault.dev_attr.attr,
305 	&sensor_dev_attr_temp3_fault.dev_attr.attr,
306 	NULL
307 };
308 
309 /* Attributes not present on MAX1805 */
310 static struct attribute *max1668_attribute_unique[] = {
311 	&sensor_dev_attr_temp4_max.dev_attr.attr,
312 	&sensor_dev_attr_temp4_min.dev_attr.attr,
313 	&sensor_dev_attr_temp4_input.dev_attr.attr,
314 	&sensor_dev_attr_temp5_max.dev_attr.attr,
315 	&sensor_dev_attr_temp5_min.dev_attr.attr,
316 	&sensor_dev_attr_temp5_input.dev_attr.attr,
317 
318 	&sensor_dev_attr_temp4_max_alarm.dev_attr.attr,
319 	&sensor_dev_attr_temp4_min_alarm.dev_attr.attr,
320 	&sensor_dev_attr_temp5_max_alarm.dev_attr.attr,
321 	&sensor_dev_attr_temp5_min_alarm.dev_attr.attr,
322 
323 	&sensor_dev_attr_temp4_fault.dev_attr.attr,
324 	&sensor_dev_attr_temp5_fault.dev_attr.attr,
325 	NULL
326 };
327 
328 static umode_t max1668_attribute_mode(struct kobject *kobj,
329 				     struct attribute *attr, int index)
330 {
331 	umode_t ret = S_IRUGO;
332 	if (read_only)
333 		return ret;
334 	if (attr == &sensor_dev_attr_temp1_max.dev_attr.attr ||
335 	    attr == &sensor_dev_attr_temp2_max.dev_attr.attr ||
336 	    attr == &sensor_dev_attr_temp3_max.dev_attr.attr ||
337 	    attr == &sensor_dev_attr_temp4_max.dev_attr.attr ||
338 	    attr == &sensor_dev_attr_temp5_max.dev_attr.attr ||
339 	    attr == &sensor_dev_attr_temp1_min.dev_attr.attr ||
340 	    attr == &sensor_dev_attr_temp2_min.dev_attr.attr ||
341 	    attr == &sensor_dev_attr_temp3_min.dev_attr.attr ||
342 	    attr == &sensor_dev_attr_temp4_min.dev_attr.attr ||
343 	    attr == &sensor_dev_attr_temp5_min.dev_attr.attr)
344 		ret |= S_IWUSR;
345 	return ret;
346 }
347 
348 static const struct attribute_group max1668_group_common = {
349 	.attrs = max1668_attribute_common,
350 	.is_visible = max1668_attribute_mode
351 };
352 
353 static const struct attribute_group max1668_group_unique = {
354 	.attrs = max1668_attribute_unique,
355 	.is_visible = max1668_attribute_mode
356 };
357 
358 /* Return 0 if detection is successful, -ENODEV otherwise */
359 static int max1668_detect(struct i2c_client *client,
360 			  struct i2c_board_info *info)
361 {
362 	struct i2c_adapter *adapter = client->adapter;
363 	const char *type_name;
364 	int man_id, dev_id;
365 
366 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
367 		return -ENODEV;
368 
369 	/* Check for unsupported part */
370 	man_id = i2c_smbus_read_byte_data(client, MAX1668_REG_MAN_ID);
371 	if (man_id != MAN_ID_MAXIM)
372 		return -ENODEV;
373 
374 	dev_id = i2c_smbus_read_byte_data(client, MAX1668_REG_DEV_ID);
375 	if (dev_id < 0)
376 		return -ENODEV;
377 
378 	type_name = NULL;
379 	if (dev_id == DEV_ID_MAX1668)
380 		type_name = "max1668";
381 	else if (dev_id == DEV_ID_MAX1805)
382 		type_name = "max1805";
383 	else if (dev_id == DEV_ID_MAX1989)
384 		type_name = "max1989";
385 
386 	if (!type_name)
387 		return -ENODEV;
388 
389 	strlcpy(info->type, type_name, I2C_NAME_SIZE);
390 
391 	return 0;
392 }
393 
394 static int max1668_probe(struct i2c_client *client,
395 			 const struct i2c_device_id *id)
396 {
397 	struct i2c_adapter *adapter = client->adapter;
398 	struct device *dev = &client->dev;
399 	struct device *hwmon_dev;
400 	struct max1668_data *data;
401 
402 	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
403 		return -ENODEV;
404 
405 	data = devm_kzalloc(dev, sizeof(struct max1668_data), GFP_KERNEL);
406 	if (!data)
407 		return -ENOMEM;
408 
409 	data->client = client;
410 	data->type = id->driver_data;
411 	mutex_init(&data->update_lock);
412 
413 	/* sysfs hooks */
414 	data->groups[0] = &max1668_group_common;
415 	if (data->type == max1668 || data->type == max1989)
416 		data->groups[1] = &max1668_group_unique;
417 
418 	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
419 							   data, data->groups);
420 	return PTR_ERR_OR_ZERO(hwmon_dev);
421 }
422 
423 static const struct i2c_device_id max1668_id[] = {
424 	{ "max1668", max1668 },
425 	{ "max1805", max1805 },
426 	{ "max1989", max1989 },
427 	{ }
428 };
429 MODULE_DEVICE_TABLE(i2c, max1668_id);
430 
431 /* This is the driver that will be inserted */
432 static struct i2c_driver max1668_driver = {
433 	.class = I2C_CLASS_HWMON,
434 	.driver = {
435 		  .name	= "max1668",
436 		  },
437 	.probe = max1668_probe,
438 	.id_table = max1668_id,
439 	.detect	= max1668_detect,
440 	.address_list = max1668_addr_list,
441 };
442 
443 module_i2c_driver(max1668_driver);
444 
445 MODULE_AUTHOR("David George <david.george@ska.ac.za>");
446 MODULE_DESCRIPTION("MAX1668 remote temperature sensor driver");
447 MODULE_LICENSE("GPL");
448