xref: /openbmc/linux/drivers/hwmon/hwmon.c (revision b308f5c744522de020da4706718de9076adeada7)
1 /*
2  * hwmon.c - part of lm_sensors, Linux kernel modules for hardware monitoring
3  *
4  * This file defines the sysfs class "hwmon", for use by sensors drivers.
5  *
6  * Copyright (C) 2005 Mark M. Hoffman <mhoffman@lightlink.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; version 2 of the License.
11  */
12 
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14 
15 #include <linux/bitops.h>
16 #include <linux/device.h>
17 #include <linux/err.h>
18 #include <linux/gfp.h>
19 #include <linux/hwmon.h>
20 #include <linux/idr.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/thermal.h>
26 
27 #define HWMON_ID_PREFIX "hwmon"
28 #define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d"
29 
30 struct hwmon_device {
31 	const char *name;
32 	struct device dev;
33 	const struct hwmon_chip_info *chip;
34 
35 	struct attribute_group group;
36 	const struct attribute_group **groups;
37 };
38 
39 #define to_hwmon_device(d) container_of(d, struct hwmon_device, dev)
40 
41 struct hwmon_device_attribute {
42 	struct device_attribute dev_attr;
43 	const struct hwmon_ops *ops;
44 	enum hwmon_sensor_types type;
45 	u32 attr;
46 	int index;
47 };
48 
49 #define to_hwmon_attr(d) \
50 	container_of(d, struct hwmon_device_attribute, dev_attr)
51 
52 /*
53  * Thermal zone information
54  * In addition to the reference to the hwmon device,
55  * also provides the sensor index.
56  */
57 struct hwmon_thermal_data {
58 	struct hwmon_device *hwdev;	/* Reference to hwmon device */
59 	int index;			/* sensor index */
60 };
61 
62 static ssize_t
63 show_name(struct device *dev, struct device_attribute *attr, char *buf)
64 {
65 	return sprintf(buf, "%s\n", to_hwmon_device(dev)->name);
66 }
67 static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);
68 
69 static struct attribute *hwmon_dev_attrs[] = {
70 	&dev_attr_name.attr,
71 	NULL
72 };
73 
74 static umode_t hwmon_dev_name_is_visible(struct kobject *kobj,
75 					 struct attribute *attr, int n)
76 {
77 	struct device *dev = container_of(kobj, struct device, kobj);
78 
79 	if (to_hwmon_device(dev)->name == NULL)
80 		return 0;
81 
82 	return attr->mode;
83 }
84 
85 static struct attribute_group hwmon_dev_attr_group = {
86 	.attrs		= hwmon_dev_attrs,
87 	.is_visible	= hwmon_dev_name_is_visible,
88 };
89 
90 static const struct attribute_group *hwmon_dev_attr_groups[] = {
91 	&hwmon_dev_attr_group,
92 	NULL
93 };
94 
95 static void hwmon_dev_release(struct device *dev)
96 {
97 	kfree(to_hwmon_device(dev));
98 }
99 
100 static struct class hwmon_class = {
101 	.name = "hwmon",
102 	.owner = THIS_MODULE,
103 	.dev_groups = hwmon_dev_attr_groups,
104 	.dev_release = hwmon_dev_release,
105 };
106 
107 static DEFINE_IDA(hwmon_ida);
108 
109 /* Thermal zone handling */
110 
111 #if IS_REACHABLE(CONFIG_THERMAL) && defined(CONFIG_THERMAL_OF)
112 static int hwmon_thermal_get_temp(void *data, int *temp)
113 {
114 	struct hwmon_thermal_data *tdata = data;
115 	struct hwmon_device *hwdev = tdata->hwdev;
116 	int ret;
117 	long t;
118 
119 	ret = hwdev->chip->ops->read(&hwdev->dev, hwmon_temp, hwmon_temp_input,
120 				     tdata->index, &t);
121 	if (ret < 0)
122 		return ret;
123 
124 	*temp = t;
125 
126 	return 0;
127 }
128 
129 static struct thermal_zone_of_device_ops hwmon_thermal_ops = {
130 	.get_temp = hwmon_thermal_get_temp,
131 };
132 
133 static int hwmon_thermal_add_sensor(struct device *dev,
134 				    struct hwmon_device *hwdev, int index)
135 {
136 	struct hwmon_thermal_data *tdata;
137 
138 	tdata = devm_kzalloc(dev, sizeof(*tdata), GFP_KERNEL);
139 	if (!tdata)
140 		return -ENOMEM;
141 
142 	tdata->hwdev = hwdev;
143 	tdata->index = index;
144 
145 	devm_thermal_zone_of_sensor_register(&hwdev->dev, index, tdata,
146 					     &hwmon_thermal_ops);
147 
148 	return 0;
149 }
150 #else
151 static int hwmon_thermal_add_sensor(struct device *dev,
152 				    struct hwmon_device *hwdev, int index)
153 {
154 	return 0;
155 }
156 #endif /* IS_REACHABLE(CONFIG_THERMAL) && defined(CONFIG_THERMAL_OF) */
157 
158 /* sysfs attribute management */
159 
160 static ssize_t hwmon_attr_show(struct device *dev,
161 			       struct device_attribute *devattr, char *buf)
162 {
163 	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
164 	long val;
165 	int ret;
166 
167 	ret = hattr->ops->read(dev, hattr->type, hattr->attr, hattr->index,
168 			       &val);
169 	if (ret < 0)
170 		return ret;
171 
172 	return sprintf(buf, "%ld\n", val);
173 }
174 
175 static ssize_t hwmon_attr_store(struct device *dev,
176 				struct device_attribute *devattr,
177 				const char *buf, size_t count)
178 {
179 	struct hwmon_device_attribute *hattr = to_hwmon_attr(devattr);
180 	long val;
181 	int ret;
182 
183 	ret = kstrtol(buf, 10, &val);
184 	if (ret < 0)
185 		return ret;
186 
187 	ret = hattr->ops->write(dev, hattr->type, hattr->attr, hattr->index,
188 				val);
189 	if (ret < 0)
190 		return ret;
191 
192 	return count;
193 }
194 
195 static int hwmon_attr_base(enum hwmon_sensor_types type)
196 {
197 	if (type == hwmon_in)
198 		return 0;
199 	return 1;
200 }
201 
202 static struct attribute *hwmon_genattr(struct device *dev,
203 				       const void *drvdata,
204 				       enum hwmon_sensor_types type,
205 				       u32 attr,
206 				       int index,
207 				       const char *template,
208 				       const struct hwmon_ops *ops)
209 {
210 	struct hwmon_device_attribute *hattr;
211 	struct device_attribute *dattr;
212 	struct attribute *a;
213 	umode_t mode;
214 	char *name;
215 
216 	/* The attribute is invisible if there is no template string */
217 	if (!template)
218 		return ERR_PTR(-ENOENT);
219 
220 	mode = ops->is_visible(drvdata, type, attr, index);
221 	if (!mode)
222 		return ERR_PTR(-ENOENT);
223 
224 	if ((mode & S_IRUGO) && !ops->read)
225 		return ERR_PTR(-EINVAL);
226 	if ((mode & S_IWUGO) && !ops->write)
227 		return ERR_PTR(-EINVAL);
228 
229 	if (type == hwmon_chip) {
230 		name = (char *)template;
231 	} else {
232 		name = devm_kzalloc(dev, strlen(template) + 16, GFP_KERNEL);
233 		if (!name)
234 			return ERR_PTR(-ENOMEM);
235 		scnprintf(name, strlen(template) + 16, template,
236 			  index + hwmon_attr_base(type));
237 	}
238 
239 	hattr = devm_kzalloc(dev, sizeof(*hattr), GFP_KERNEL);
240 	if (!hattr)
241 		return ERR_PTR(-ENOMEM);
242 
243 	hattr->type = type;
244 	hattr->attr = attr;
245 	hattr->index = index;
246 	hattr->ops = ops;
247 
248 	dattr = &hattr->dev_attr;
249 	dattr->show = hwmon_attr_show;
250 	dattr->store = hwmon_attr_store;
251 
252 	a = &dattr->attr;
253 	sysfs_attr_init(a);
254 	a->name = name;
255 	a->mode = mode;
256 
257 	return a;
258 }
259 
260 static const char * const hwmon_chip_attr_templates[] = {
261 	[hwmon_chip_temp_reset_history] = "temp_reset_history",
262 	[hwmon_chip_in_reset_history] = "in_reset_history",
263 	[hwmon_chip_curr_reset_history] = "curr_reset_history",
264 	[hwmon_chip_power_reset_history] = "power_reset_history",
265 	[hwmon_chip_update_interval] = "update_interval",
266 	[hwmon_chip_alarms] = "alarms",
267 };
268 
269 static const char * const hwmon_temp_attr_templates[] = {
270 	[hwmon_temp_input] = "temp%d_input",
271 	[hwmon_temp_type] = "temp%d_type",
272 	[hwmon_temp_lcrit] = "temp%d_lcrit",
273 	[hwmon_temp_lcrit_hyst] = "temp%d_lcrit_hyst",
274 	[hwmon_temp_min] = "temp%d_min",
275 	[hwmon_temp_min_hyst] = "temp%d_min_hyst",
276 	[hwmon_temp_max] = "temp%d_max",
277 	[hwmon_temp_max_hyst] = "temp%d_max_hyst",
278 	[hwmon_temp_crit] = "temp%d_crit",
279 	[hwmon_temp_crit_hyst] = "temp%d_crit_hyst",
280 	[hwmon_temp_emergency] = "temp%d_emergency",
281 	[hwmon_temp_emergency_hyst] = "temp%d_emergency_hyst",
282 	[hwmon_temp_alarm] = "temp%d_alarm",
283 	[hwmon_temp_lcrit_alarm] = "temp%d_lcrit_alarm",
284 	[hwmon_temp_min_alarm] = "temp%d_min_alarm",
285 	[hwmon_temp_max_alarm] = "temp%d_max_alarm",
286 	[hwmon_temp_crit_alarm] = "temp%d_crit_alarm",
287 	[hwmon_temp_emergency_alarm] = "temp%d_emergency_alarm",
288 	[hwmon_temp_fault] = "temp%d_fault",
289 	[hwmon_temp_offset] = "temp%d_offset",
290 	[hwmon_temp_label] = "temp%d_label",
291 	[hwmon_temp_lowest] = "temp%d_lowest",
292 	[hwmon_temp_highest] = "temp%d_highest",
293 	[hwmon_temp_reset_history] = "temp%d_reset_history",
294 };
295 
296 static const char * const hwmon_in_attr_templates[] = {
297 	[hwmon_in_input] = "in%d_input",
298 	[hwmon_in_min] = "in%d_min",
299 	[hwmon_in_max] = "in%d_max",
300 	[hwmon_in_lcrit] = "in%d_lcrit",
301 	[hwmon_in_crit] = "in%d_crit",
302 	[hwmon_in_average] = "in%d_average",
303 	[hwmon_in_lowest] = "in%d_lowest",
304 	[hwmon_in_highest] = "in%d_highest",
305 	[hwmon_in_reset_history] = "in%d_reset_history",
306 	[hwmon_in_label] = "in%d_label",
307 	[hwmon_in_alarm] = "in%d_alarm",
308 	[hwmon_in_min_alarm] = "in%d_min_alarm",
309 	[hwmon_in_max_alarm] = "in%d_max_alarm",
310 	[hwmon_in_lcrit_alarm] = "in%d_lcrit_alarm",
311 	[hwmon_in_crit_alarm] = "in%d_crit_alarm",
312 };
313 
314 static const char * const hwmon_curr_attr_templates[] = {
315 	[hwmon_curr_input] = "curr%d_input",
316 	[hwmon_curr_min] = "curr%d_min",
317 	[hwmon_curr_max] = "curr%d_max",
318 	[hwmon_curr_lcrit] = "curr%d_lcrit",
319 	[hwmon_curr_crit] = "curr%d_crit",
320 	[hwmon_curr_average] = "curr%d_average",
321 	[hwmon_curr_lowest] = "curr%d_lowest",
322 	[hwmon_curr_highest] = "curr%d_highest",
323 	[hwmon_curr_reset_history] = "curr%d_reset_history",
324 	[hwmon_curr_label] = "curr%d_label",
325 	[hwmon_curr_alarm] = "curr%d_alarm",
326 	[hwmon_curr_min_alarm] = "curr%d_min_alarm",
327 	[hwmon_curr_max_alarm] = "curr%d_max_alarm",
328 	[hwmon_curr_lcrit_alarm] = "curr%d_lcrit_alarm",
329 	[hwmon_curr_crit_alarm] = "curr%d_crit_alarm",
330 };
331 
332 static const char * const hwmon_power_attr_templates[] = {
333 	[hwmon_power_average] = "power%d_average",
334 	[hwmon_power_average_interval] = "power%d_average_interval",
335 	[hwmon_power_average_interval_max] = "power%d_interval_max",
336 	[hwmon_power_average_interval_min] = "power%d_interval_min",
337 	[hwmon_power_average_highest] = "power%d_average_highest",
338 	[hwmon_power_average_lowest] = "power%d_average_lowest",
339 	[hwmon_power_average_max] = "power%d_average_max",
340 	[hwmon_power_average_min] = "power%d_average_min",
341 	[hwmon_power_input] = "power%d_input",
342 	[hwmon_power_input_highest] = "power%d_input_highest",
343 	[hwmon_power_input_lowest] = "power%d_input_lowest",
344 	[hwmon_power_reset_history] = "power%d_reset_history",
345 	[hwmon_power_accuracy] = "power%d_accuracy",
346 	[hwmon_power_cap] = "power%d_cap",
347 	[hwmon_power_cap_hyst] = "power%d_cap_hyst",
348 	[hwmon_power_cap_max] = "power%d_cap_max",
349 	[hwmon_power_cap_min] = "power%d_cap_min",
350 	[hwmon_power_max] = "power%d_max",
351 	[hwmon_power_crit] = "power%d_crit",
352 	[hwmon_power_label] = "power%d_label",
353 	[hwmon_power_alarm] = "power%d_alarm",
354 	[hwmon_power_cap_alarm] = "power%d_cap_alarm",
355 	[hwmon_power_max_alarm] = "power%d_max_alarm",
356 	[hwmon_power_crit_alarm] = "power%d_crit_alarm",
357 };
358 
359 static const char * const *__templates[] = {
360 	[hwmon_chip] = hwmon_chip_attr_templates,
361 	[hwmon_temp] = hwmon_temp_attr_templates,
362 	[hwmon_in] = hwmon_in_attr_templates,
363 	[hwmon_curr] = hwmon_curr_attr_templates,
364 	[hwmon_power] = hwmon_power_attr_templates,
365 };
366 
367 static const int __templates_size[] = {
368 	[hwmon_chip] = ARRAY_SIZE(hwmon_chip_attr_templates),
369 	[hwmon_temp] = ARRAY_SIZE(hwmon_temp_attr_templates),
370 	[hwmon_in] = ARRAY_SIZE(hwmon_in_attr_templates),
371 	[hwmon_curr] = ARRAY_SIZE(hwmon_curr_attr_templates),
372 	[hwmon_power] = ARRAY_SIZE(hwmon_power_attr_templates),
373 };
374 
375 static int hwmon_num_channel_attrs(const struct hwmon_channel_info *info)
376 {
377 	int i, n;
378 
379 	for (i = n = 0; info->config[i]; i++)
380 		n += hweight32(info->config[i]);
381 
382 	return n;
383 }
384 
385 static int hwmon_genattrs(struct device *dev,
386 			  const void *drvdata,
387 			  struct attribute **attrs,
388 			  const struct hwmon_ops *ops,
389 			  const struct hwmon_channel_info *info)
390 {
391 	const char * const *templates;
392 	int template_size;
393 	int i, aindex = 0;
394 
395 	if (info->type >= ARRAY_SIZE(__templates))
396 		return -EINVAL;
397 
398 	templates = __templates[info->type];
399 	template_size = __templates_size[info->type];
400 
401 	for (i = 0; info->config[i]; i++) {
402 		u32 attr_mask = info->config[i];
403 		u32 attr;
404 
405 		while (attr_mask) {
406 			struct attribute *a;
407 
408 			attr = __ffs(attr_mask);
409 			attr_mask &= ~BIT(attr);
410 			if (attr >= template_size)
411 				return -EINVAL;
412 			a = hwmon_genattr(dev, drvdata, info->type, attr, i,
413 					  templates[attr], ops);
414 			if (IS_ERR(a)) {
415 				if (PTR_ERR(a) != -ENOENT)
416 					return PTR_ERR(a);
417 				continue;
418 			}
419 			attrs[aindex++] = a;
420 		}
421 	}
422 	return aindex;
423 }
424 
425 static struct attribute **
426 __hwmon_create_attrs(struct device *dev, const void *drvdata,
427 		     const struct hwmon_chip_info *chip)
428 {
429 	int ret, i, aindex = 0, nattrs = 0;
430 	struct attribute **attrs;
431 
432 	for (i = 0; chip->info[i]; i++)
433 		nattrs += hwmon_num_channel_attrs(chip->info[i]);
434 
435 	if (nattrs == 0)
436 		return ERR_PTR(-EINVAL);
437 
438 	attrs = devm_kcalloc(dev, nattrs + 1, sizeof(*attrs), GFP_KERNEL);
439 	if (!attrs)
440 		return ERR_PTR(-ENOMEM);
441 
442 	for (i = 0; chip->info[i]; i++) {
443 		ret = hwmon_genattrs(dev, drvdata, &attrs[aindex], chip->ops,
444 				     chip->info[i]);
445 		if (ret < 0)
446 			return ERR_PTR(ret);
447 		aindex += ret;
448 	}
449 
450 	return attrs;
451 }
452 
453 static struct device *
454 __hwmon_device_register(struct device *dev, const char *name, void *drvdata,
455 			const struct hwmon_chip_info *chip,
456 			const struct attribute_group **groups)
457 {
458 	struct hwmon_device *hwdev;
459 	struct device *hdev;
460 	int i, j, err, id;
461 
462 	/* Do not accept invalid characters in hwmon name attribute */
463 	if (name && (!strlen(name) || strpbrk(name, "-* \t\n")))
464 		return ERR_PTR(-EINVAL);
465 
466 	id = ida_simple_get(&hwmon_ida, 0, 0, GFP_KERNEL);
467 	if (id < 0)
468 		return ERR_PTR(id);
469 
470 	hwdev = kzalloc(sizeof(*hwdev), GFP_KERNEL);
471 	if (hwdev == NULL) {
472 		err = -ENOMEM;
473 		goto ida_remove;
474 	}
475 
476 	hdev = &hwdev->dev;
477 
478 	if (chip && chip->ops->is_visible) {
479 		struct attribute **attrs;
480 		int ngroups = 2;
481 
482 		if (groups)
483 			for (i = 0; groups[i]; i++)
484 				ngroups++;
485 
486 		hwdev->groups = devm_kcalloc(dev, ngroups, sizeof(*groups),
487 					     GFP_KERNEL);
488 		if (!hwdev->groups)
489 			return ERR_PTR(-ENOMEM);
490 
491 		attrs = __hwmon_create_attrs(dev, drvdata, chip);
492 		if (IS_ERR(attrs)) {
493 			err = PTR_ERR(attrs);
494 			goto free_hwmon;
495 		}
496 
497 		hwdev->group.attrs = attrs;
498 		ngroups = 0;
499 		hwdev->groups[ngroups++] = &hwdev->group;
500 
501 		if (groups) {
502 			for (i = 0; groups[i]; i++)
503 				hwdev->groups[ngroups++] = groups[i];
504 		}
505 
506 		hdev->groups = hwdev->groups;
507 	} else {
508 		hdev->groups = groups;
509 	}
510 
511 	hwdev->name = name;
512 	hdev->class = &hwmon_class;
513 	hdev->parent = dev;
514 	hdev->of_node = dev ? dev->of_node : NULL;
515 	hwdev->chip = chip;
516 	dev_set_drvdata(hdev, drvdata);
517 	dev_set_name(hdev, HWMON_ID_FORMAT, id);
518 	err = device_register(hdev);
519 	if (err)
520 		goto free_hwmon;
521 
522 	if (chip && chip->ops->is_visible && chip->ops->read &&
523 	    chip->info[0]->type == hwmon_chip &&
524 	    (chip->info[0]->config[0] & HWMON_C_REGISTER_TZ)) {
525 		const struct hwmon_channel_info **info = chip->info;
526 
527 		for (i = 1; info[i]; i++) {
528 			if (info[i]->type != hwmon_temp)
529 				continue;
530 
531 			for (j = 0; info[i]->config[j]; j++) {
532 				if (!chip->ops->is_visible(drvdata, hwmon_temp,
533 							   hwmon_temp_input, j))
534 					continue;
535 				if (info[i]->config[j] & HWMON_T_INPUT)
536 					hwmon_thermal_add_sensor(dev, hwdev, j);
537 			}
538 		}
539 	}
540 
541 	return hdev;
542 
543 free_hwmon:
544 	kfree(hwdev);
545 ida_remove:
546 	ida_simple_remove(&hwmon_ida, id);
547 	return ERR_PTR(err);
548 }
549 
550 /**
551  * hwmon_device_register_with_groups - register w/ hwmon
552  * @dev: the parent device
553  * @name: hwmon name attribute
554  * @drvdata: driver data to attach to created device
555  * @groups: List of attribute groups to create
556  *
557  * hwmon_device_unregister() must be called when the device is no
558  * longer needed.
559  *
560  * Returns the pointer to the new device.
561  */
562 struct device *
563 hwmon_device_register_with_groups(struct device *dev, const char *name,
564 				  void *drvdata,
565 				  const struct attribute_group **groups)
566 {
567 	return __hwmon_device_register(dev, name, drvdata, NULL, groups);
568 }
569 EXPORT_SYMBOL_GPL(hwmon_device_register_with_groups);
570 
571 /**
572  * hwmon_device_register_with_info - register w/ hwmon
573  * @dev: the parent device
574  * @name: hwmon name attribute
575  * @drvdata: driver data to attach to created device
576  * @info: Pointer to hwmon chip information
577  * @groups - pointer to list of driver specific attribute groups
578  *
579  * hwmon_device_unregister() must be called when the device is no
580  * longer needed.
581  *
582  * Returns the pointer to the new device.
583  */
584 struct device *
585 hwmon_device_register_with_info(struct device *dev, const char *name,
586 				void *drvdata,
587 				const struct hwmon_chip_info *chip,
588 				const struct attribute_group **groups)
589 {
590 	if (chip && (!chip->ops || !chip->info))
591 		return ERR_PTR(-EINVAL);
592 
593 	return __hwmon_device_register(dev, name, drvdata, chip, groups);
594 }
595 EXPORT_SYMBOL_GPL(hwmon_device_register_with_info);
596 
597 /**
598  * hwmon_device_register - register w/ hwmon
599  * @dev: the device to register
600  *
601  * hwmon_device_unregister() must be called when the device is no
602  * longer needed.
603  *
604  * Returns the pointer to the new device.
605  */
606 struct device *hwmon_device_register(struct device *dev)
607 {
608 	return hwmon_device_register_with_groups(dev, NULL, NULL, NULL);
609 }
610 EXPORT_SYMBOL_GPL(hwmon_device_register);
611 
612 /**
613  * hwmon_device_unregister - removes the previously registered class device
614  *
615  * @dev: the class device to destroy
616  */
617 void hwmon_device_unregister(struct device *dev)
618 {
619 	int id;
620 
621 	if (likely(sscanf(dev_name(dev), HWMON_ID_FORMAT, &id) == 1)) {
622 		device_unregister(dev);
623 		ida_simple_remove(&hwmon_ida, id);
624 	} else
625 		dev_dbg(dev->parent,
626 			"hwmon_device_unregister() failed: bad class ID!\n");
627 }
628 EXPORT_SYMBOL_GPL(hwmon_device_unregister);
629 
630 static void devm_hwmon_release(struct device *dev, void *res)
631 {
632 	struct device *hwdev = *(struct device **)res;
633 
634 	hwmon_device_unregister(hwdev);
635 }
636 
637 /**
638  * devm_hwmon_device_register_with_groups - register w/ hwmon
639  * @dev: the parent device
640  * @name: hwmon name attribute
641  * @drvdata: driver data to attach to created device
642  * @groups: List of attribute groups to create
643  *
644  * Returns the pointer to the new device. The new device is automatically
645  * unregistered with the parent device.
646  */
647 struct device *
648 devm_hwmon_device_register_with_groups(struct device *dev, const char *name,
649 				       void *drvdata,
650 				       const struct attribute_group **groups)
651 {
652 	struct device **ptr, *hwdev;
653 
654 	if (!dev)
655 		return ERR_PTR(-EINVAL);
656 
657 	ptr = devres_alloc(devm_hwmon_release, sizeof(*ptr), GFP_KERNEL);
658 	if (!ptr)
659 		return ERR_PTR(-ENOMEM);
660 
661 	hwdev = hwmon_device_register_with_groups(dev, name, drvdata, groups);
662 	if (IS_ERR(hwdev))
663 		goto error;
664 
665 	*ptr = hwdev;
666 	devres_add(dev, ptr);
667 	return hwdev;
668 
669 error:
670 	devres_free(ptr);
671 	return hwdev;
672 }
673 EXPORT_SYMBOL_GPL(devm_hwmon_device_register_with_groups);
674 
675 /**
676  * devm_hwmon_device_register_with_info - register w/ hwmon
677  * @dev: the parent device
678  * @name: hwmon name attribute
679  * @drvdata: driver data to attach to created device
680  * @info: Pointer to hwmon chip information
681  * @groups - pointer to list of driver specific attribute groups
682  *
683  * Returns the pointer to the new device. The new device is automatically
684  * unregistered with the parent device.
685  */
686 struct device *
687 devm_hwmon_device_register_with_info(struct device *dev, const char *name,
688 				     void *drvdata,
689 				     const struct hwmon_chip_info *chip,
690 				     const struct attribute_group **groups)
691 {
692 	struct device **ptr, *hwdev;
693 
694 	if (!dev)
695 		return ERR_PTR(-EINVAL);
696 
697 	ptr = devres_alloc(devm_hwmon_release, sizeof(*ptr), GFP_KERNEL);
698 	if (!ptr)
699 		return ERR_PTR(-ENOMEM);
700 
701 	hwdev = hwmon_device_register_with_info(dev, name, drvdata, chip,
702 						groups);
703 	if (IS_ERR(hwdev))
704 		goto error;
705 
706 	*ptr = hwdev;
707 	devres_add(dev, ptr);
708 
709 	return hwdev;
710 
711 error:
712 	devres_free(ptr);
713 	return hwdev;
714 }
715 EXPORT_SYMBOL_GPL(devm_hwmon_device_register_with_info);
716 
717 static int devm_hwmon_match(struct device *dev, void *res, void *data)
718 {
719 	struct device **hwdev = res;
720 
721 	return *hwdev == data;
722 }
723 
724 /**
725  * devm_hwmon_device_unregister - removes a previously registered hwmon device
726  *
727  * @dev: the parent device of the device to unregister
728  */
729 void devm_hwmon_device_unregister(struct device *dev)
730 {
731 	WARN_ON(devres_release(dev, devm_hwmon_release, devm_hwmon_match, dev));
732 }
733 EXPORT_SYMBOL_GPL(devm_hwmon_device_unregister);
734 
735 static void __init hwmon_pci_quirks(void)
736 {
737 #if defined CONFIG_X86 && defined CONFIG_PCI
738 	struct pci_dev *sb;
739 	u16 base;
740 	u8 enable;
741 
742 	/* Open access to 0x295-0x296 on MSI MS-7031 */
743 	sb = pci_get_device(PCI_VENDOR_ID_ATI, 0x436c, NULL);
744 	if (sb) {
745 		if (sb->subsystem_vendor == 0x1462 &&	/* MSI */
746 		    sb->subsystem_device == 0x0031) {	/* MS-7031 */
747 			pci_read_config_byte(sb, 0x48, &enable);
748 			pci_read_config_word(sb, 0x64, &base);
749 
750 			if (base == 0 && !(enable & BIT(2))) {
751 				dev_info(&sb->dev,
752 					 "Opening wide generic port at 0x295\n");
753 				pci_write_config_word(sb, 0x64, 0x295);
754 				pci_write_config_byte(sb, 0x48,
755 						      enable | BIT(2));
756 			}
757 		}
758 		pci_dev_put(sb);
759 	}
760 #endif
761 }
762 
763 static int __init hwmon_init(void)
764 {
765 	int err;
766 
767 	hwmon_pci_quirks();
768 
769 	err = class_register(&hwmon_class);
770 	if (err) {
771 		pr_err("couldn't register hwmon sysfs class\n");
772 		return err;
773 	}
774 	return 0;
775 }
776 
777 static void __exit hwmon_exit(void)
778 {
779 	class_unregister(&hwmon_class);
780 }
781 
782 subsys_initcall(hwmon_init);
783 module_exit(hwmon_exit);
784 
785 MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>");
786 MODULE_DESCRIPTION("hardware monitoring sysfs/class support");
787 MODULE_LICENSE("GPL");
788 
789