treewide: remove redundant IS_ERR() before error code check
[linux/fpc-iii.git] / drivers / misc / enclosure.c
blob3c2d405bc79b951f88a618289bfc8d47e16fac52
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Enclosure Services
5 * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
7 **-----------------------------------------------------------------------------
8 **
9 **
10 **-----------------------------------------------------------------------------
12 #include <linux/device.h>
13 #include <linux/enclosure.h>
14 #include <linux/err.h>
15 #include <linux/list.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/mutex.h>
19 #include <linux/slab.h>
21 static LIST_HEAD(container_list);
22 static DEFINE_MUTEX(container_list_lock);
23 static struct class enclosure_class;
25 /**
26 * enclosure_find - find an enclosure given a parent device
27 * @dev: the parent to match against
28 * @start: Optional enclosure device to start from (NULL if none)
30 * Looks through the list of registered enclosures to find all those
31 * with @dev as a parent. Returns NULL if no enclosure is
32 * found. @start can be used as a starting point to obtain multiple
33 * enclosures per parent (should begin with NULL and then be set to
34 * each returned enclosure device). Obtains a reference to the
35 * enclosure class device which must be released with device_put().
36 * If @start is not NULL, a reference must be taken on it which is
37 * released before returning (this allows a loop through all
38 * enclosures to exit with only the reference on the enclosure of
39 * interest held). Note that the @dev may correspond to the actual
40 * device housing the enclosure, in which case no iteration via @start
41 * is required.
43 struct enclosure_device *enclosure_find(struct device *dev,
44 struct enclosure_device *start)
46 struct enclosure_device *edev;
48 mutex_lock(&container_list_lock);
49 edev = list_prepare_entry(start, &container_list, node);
50 if (start)
51 put_device(&start->edev);
53 list_for_each_entry_continue(edev, &container_list, node) {
54 struct device *parent = edev->edev.parent;
55 /* parent might not be immediate, so iterate up to
56 * the root of the tree if necessary */
57 while (parent) {
58 if (parent == dev) {
59 get_device(&edev->edev);
60 mutex_unlock(&container_list_lock);
61 return edev;
63 parent = parent->parent;
66 mutex_unlock(&container_list_lock);
68 return NULL;
70 EXPORT_SYMBOL_GPL(enclosure_find);
72 /**
73 * enclosure_for_each_device - calls a function for each enclosure
74 * @fn: the function to call
75 * @data: the data to pass to each call
77 * Loops over all the enclosures calling the function.
79 * Note, this function uses a mutex which will be held across calls to
80 * @fn, so it must have non atomic context, and @fn may (although it
81 * should not) sleep or otherwise cause the mutex to be held for
82 * indefinite periods
84 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
85 void *data)
87 int error = 0;
88 struct enclosure_device *edev;
90 mutex_lock(&container_list_lock);
91 list_for_each_entry(edev, &container_list, node) {
92 error = fn(edev, data);
93 if (error)
94 break;
96 mutex_unlock(&container_list_lock);
98 return error;
100 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
103 * enclosure_register - register device as an enclosure
105 * @dev: device containing the enclosure
106 * @components: number of components in the enclosure
108 * This sets up the device for being an enclosure. Note that @dev does
109 * not have to be a dedicated enclosure device. It may be some other type
110 * of device that additionally responds to enclosure services
112 struct enclosure_device *
113 enclosure_register(struct device *dev, const char *name, int components,
114 struct enclosure_component_callbacks *cb)
116 struct enclosure_device *edev =
117 kzalloc(struct_size(edev, component, components), GFP_KERNEL);
118 int err, i;
120 BUG_ON(!cb);
122 if (!edev)
123 return ERR_PTR(-ENOMEM);
125 edev->components = components;
127 edev->edev.class = &enclosure_class;
128 edev->edev.parent = get_device(dev);
129 edev->cb = cb;
130 dev_set_name(&edev->edev, "%s", name);
131 err = device_register(&edev->edev);
132 if (err)
133 goto err;
135 for (i = 0; i < components; i++) {
136 edev->component[i].number = -1;
137 edev->component[i].slot = -1;
138 edev->component[i].power_status = -1;
141 mutex_lock(&container_list_lock);
142 list_add_tail(&edev->node, &container_list);
143 mutex_unlock(&container_list_lock);
145 return edev;
147 err:
148 put_device(edev->edev.parent);
149 kfree(edev);
150 return ERR_PTR(err);
152 EXPORT_SYMBOL_GPL(enclosure_register);
154 static struct enclosure_component_callbacks enclosure_null_callbacks;
157 * enclosure_unregister - remove an enclosure
159 * @edev: the registered enclosure to remove;
161 void enclosure_unregister(struct enclosure_device *edev)
163 int i;
165 mutex_lock(&container_list_lock);
166 list_del(&edev->node);
167 mutex_unlock(&container_list_lock);
169 for (i = 0; i < edev->components; i++)
170 if (edev->component[i].number != -1)
171 device_unregister(&edev->component[i].cdev);
173 /* prevent any callbacks into service user */
174 edev->cb = &enclosure_null_callbacks;
175 device_unregister(&edev->edev);
177 EXPORT_SYMBOL_GPL(enclosure_unregister);
179 #define ENCLOSURE_NAME_SIZE 64
180 #define COMPONENT_NAME_SIZE 64
182 static void enclosure_link_name(struct enclosure_component *cdev, char *name)
184 strcpy(name, "enclosure_device:");
185 strcat(name, dev_name(&cdev->cdev));
188 static void enclosure_remove_links(struct enclosure_component *cdev)
190 char name[ENCLOSURE_NAME_SIZE];
192 enclosure_link_name(cdev, name);
195 * In odd circumstances, like multipath devices, something else may
196 * already have removed the links, so check for this condition first.
198 if (cdev->dev->kobj.sd)
199 sysfs_remove_link(&cdev->dev->kobj, name);
201 if (cdev->cdev.kobj.sd)
202 sysfs_remove_link(&cdev->cdev.kobj, "device");
205 static int enclosure_add_links(struct enclosure_component *cdev)
207 int error;
208 char name[ENCLOSURE_NAME_SIZE];
210 error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
211 if (error)
212 return error;
214 enclosure_link_name(cdev, name);
215 error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
216 if (error)
217 sysfs_remove_link(&cdev->cdev.kobj, "device");
219 return error;
222 static void enclosure_release(struct device *cdev)
224 struct enclosure_device *edev = to_enclosure_device(cdev);
226 put_device(cdev->parent);
227 kfree(edev);
230 static void enclosure_component_release(struct device *dev)
232 struct enclosure_component *cdev = to_enclosure_component(dev);
234 if (cdev->dev) {
235 enclosure_remove_links(cdev);
236 put_device(cdev->dev);
238 put_device(dev->parent);
241 static struct enclosure_component *
242 enclosure_component_find_by_name(struct enclosure_device *edev,
243 const char *name)
245 int i;
246 const char *cname;
247 struct enclosure_component *ecomp;
249 if (!edev || !name || !name[0])
250 return NULL;
252 for (i = 0; i < edev->components; i++) {
253 ecomp = &edev->component[i];
254 cname = dev_name(&ecomp->cdev);
255 if (ecomp->number != -1 &&
256 cname && cname[0] &&
257 !strcmp(cname, name))
258 return ecomp;
261 return NULL;
264 static const struct attribute_group *enclosure_component_groups[];
267 * enclosure_component_alloc - prepare a new enclosure component
268 * @edev: the enclosure to add the component
269 * @num: the device number
270 * @type: the type of component being added
271 * @name: an optional name to appear in sysfs (leave NULL if none)
273 * The name is optional for enclosures that give their components a unique
274 * name. If not, leave the field NULL and a name will be assigned.
276 * Returns a pointer to the enclosure component or an error.
278 struct enclosure_component *
279 enclosure_component_alloc(struct enclosure_device *edev,
280 unsigned int number,
281 enum enclosure_component_type type,
282 const char *name)
284 struct enclosure_component *ecomp;
285 struct device *cdev;
286 int i;
287 char newname[COMPONENT_NAME_SIZE];
289 if (number >= edev->components)
290 return ERR_PTR(-EINVAL);
292 ecomp = &edev->component[number];
294 if (ecomp->number != -1)
295 return ERR_PTR(-EINVAL);
297 ecomp->type = type;
298 ecomp->number = number;
299 cdev = &ecomp->cdev;
300 cdev->parent = get_device(&edev->edev);
302 if (name && name[0]) {
303 /* Some hardware (e.g. enclosure in RX300 S6) has components
304 * with non unique names. Registering duplicates in sysfs
305 * will lead to warnings during bootup. So make the names
306 * unique by appending consecutive numbers -1, -2, ... */
307 i = 1;
308 snprintf(newname, COMPONENT_NAME_SIZE,
309 "%s", name);
310 while (enclosure_component_find_by_name(edev, newname))
311 snprintf(newname, COMPONENT_NAME_SIZE,
312 "%s-%i", name, i++);
313 dev_set_name(cdev, "%s", newname);
314 } else
315 dev_set_name(cdev, "%u", number);
317 cdev->release = enclosure_component_release;
318 cdev->groups = enclosure_component_groups;
320 return ecomp;
322 EXPORT_SYMBOL_GPL(enclosure_component_alloc);
325 * enclosure_component_register - publishes an initialized enclosure component
326 * @ecomp: component to add
328 * Returns 0 on successful registration, releases the component otherwise
330 int enclosure_component_register(struct enclosure_component *ecomp)
332 struct device *cdev;
333 int err;
335 cdev = &ecomp->cdev;
336 err = device_register(cdev);
337 if (err) {
338 ecomp->number = -1;
339 put_device(cdev);
340 return err;
343 return 0;
345 EXPORT_SYMBOL_GPL(enclosure_component_register);
348 * enclosure_add_device - add a device as being part of an enclosure
349 * @edev: the enclosure device being added to.
350 * @num: the number of the component
351 * @dev: the device being added
353 * Declares a real device to reside in slot (or identifier) @num of an
354 * enclosure. This will cause the relevant sysfs links to appear.
355 * This function may also be used to change a device associated with
356 * an enclosure without having to call enclosure_remove_device() in
357 * between.
359 * Returns zero on success or an error.
361 int enclosure_add_device(struct enclosure_device *edev, int component,
362 struct device *dev)
364 struct enclosure_component *cdev;
365 int err;
367 if (!edev || component >= edev->components)
368 return -EINVAL;
370 cdev = &edev->component[component];
372 if (cdev->dev == dev)
373 return -EEXIST;
375 if (cdev->dev) {
376 enclosure_remove_links(cdev);
377 put_device(cdev->dev);
379 cdev->dev = get_device(dev);
380 err = enclosure_add_links(cdev);
381 if (err) {
382 put_device(cdev->dev);
383 cdev->dev = NULL;
385 return err;
387 EXPORT_SYMBOL_GPL(enclosure_add_device);
390 * enclosure_remove_device - remove a device from an enclosure
391 * @edev: the enclosure device
392 * @num: the number of the component to remove
394 * Returns zero on success or an error.
397 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
399 struct enclosure_component *cdev;
400 int i;
402 if (!edev || !dev)
403 return -EINVAL;
405 for (i = 0; i < edev->components; i++) {
406 cdev = &edev->component[i];
407 if (cdev->dev == dev) {
408 enclosure_remove_links(cdev);
409 put_device(dev);
410 cdev->dev = NULL;
411 return 0;
414 return -ENODEV;
416 EXPORT_SYMBOL_GPL(enclosure_remove_device);
419 * sysfs pieces below
422 static ssize_t components_show(struct device *cdev,
423 struct device_attribute *attr, char *buf)
425 struct enclosure_device *edev = to_enclosure_device(cdev);
427 return snprintf(buf, 40, "%d\n", edev->components);
429 static DEVICE_ATTR_RO(components);
431 static ssize_t id_show(struct device *cdev,
432 struct device_attribute *attr,
433 char *buf)
435 struct enclosure_device *edev = to_enclosure_device(cdev);
437 if (edev->cb->show_id)
438 return edev->cb->show_id(edev, buf);
439 return -EINVAL;
441 static DEVICE_ATTR_RO(id);
443 static struct attribute *enclosure_class_attrs[] = {
444 &dev_attr_components.attr,
445 &dev_attr_id.attr,
446 NULL,
448 ATTRIBUTE_GROUPS(enclosure_class);
450 static struct class enclosure_class = {
451 .name = "enclosure",
452 .owner = THIS_MODULE,
453 .dev_release = enclosure_release,
454 .dev_groups = enclosure_class_groups,
457 static const char *const enclosure_status[] = {
458 [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
459 [ENCLOSURE_STATUS_OK] = "OK",
460 [ENCLOSURE_STATUS_CRITICAL] = "critical",
461 [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
462 [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
463 [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
464 [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
465 [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
466 [ENCLOSURE_STATUS_MAX] = NULL,
469 static const char *const enclosure_type[] = {
470 [ENCLOSURE_COMPONENT_DEVICE] = "device",
471 [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
474 static ssize_t get_component_fault(struct device *cdev,
475 struct device_attribute *attr, char *buf)
477 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
478 struct enclosure_component *ecomp = to_enclosure_component(cdev);
480 if (edev->cb->get_fault)
481 edev->cb->get_fault(edev, ecomp);
482 return snprintf(buf, 40, "%d\n", ecomp->fault);
485 static ssize_t set_component_fault(struct device *cdev,
486 struct device_attribute *attr,
487 const char *buf, size_t count)
489 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
490 struct enclosure_component *ecomp = to_enclosure_component(cdev);
491 int val = simple_strtoul(buf, NULL, 0);
493 if (edev->cb->set_fault)
494 edev->cb->set_fault(edev, ecomp, val);
495 return count;
498 static ssize_t get_component_status(struct device *cdev,
499 struct device_attribute *attr,char *buf)
501 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
502 struct enclosure_component *ecomp = to_enclosure_component(cdev);
504 if (edev->cb->get_status)
505 edev->cb->get_status(edev, ecomp);
506 return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
509 static ssize_t set_component_status(struct device *cdev,
510 struct device_attribute *attr,
511 const char *buf, size_t count)
513 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
514 struct enclosure_component *ecomp = to_enclosure_component(cdev);
515 int i;
517 for (i = 0; enclosure_status[i]; i++) {
518 if (strncmp(buf, enclosure_status[i],
519 strlen(enclosure_status[i])) == 0 &&
520 (buf[strlen(enclosure_status[i])] == '\n' ||
521 buf[strlen(enclosure_status[i])] == '\0'))
522 break;
525 if (enclosure_status[i] && edev->cb->set_status) {
526 edev->cb->set_status(edev, ecomp, i);
527 return count;
528 } else
529 return -EINVAL;
532 static ssize_t get_component_active(struct device *cdev,
533 struct device_attribute *attr, char *buf)
535 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
536 struct enclosure_component *ecomp = to_enclosure_component(cdev);
538 if (edev->cb->get_active)
539 edev->cb->get_active(edev, ecomp);
540 return snprintf(buf, 40, "%d\n", ecomp->active);
543 static ssize_t set_component_active(struct device *cdev,
544 struct device_attribute *attr,
545 const char *buf, size_t count)
547 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
548 struct enclosure_component *ecomp = to_enclosure_component(cdev);
549 int val = simple_strtoul(buf, NULL, 0);
551 if (edev->cb->set_active)
552 edev->cb->set_active(edev, ecomp, val);
553 return count;
556 static ssize_t get_component_locate(struct device *cdev,
557 struct device_attribute *attr, char *buf)
559 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
560 struct enclosure_component *ecomp = to_enclosure_component(cdev);
562 if (edev->cb->get_locate)
563 edev->cb->get_locate(edev, ecomp);
564 return snprintf(buf, 40, "%d\n", ecomp->locate);
567 static ssize_t set_component_locate(struct device *cdev,
568 struct device_attribute *attr,
569 const char *buf, size_t count)
571 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
572 struct enclosure_component *ecomp = to_enclosure_component(cdev);
573 int val = simple_strtoul(buf, NULL, 0);
575 if (edev->cb->set_locate)
576 edev->cb->set_locate(edev, ecomp, val);
577 return count;
580 static ssize_t get_component_power_status(struct device *cdev,
581 struct device_attribute *attr,
582 char *buf)
584 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
585 struct enclosure_component *ecomp = to_enclosure_component(cdev);
587 if (edev->cb->get_power_status)
588 edev->cb->get_power_status(edev, ecomp);
590 /* If still uninitialized, the callback failed or does not exist. */
591 if (ecomp->power_status == -1)
592 return (edev->cb->get_power_status) ? -EIO : -ENOTTY;
594 return snprintf(buf, 40, "%s\n", ecomp->power_status ? "on" : "off");
597 static ssize_t set_component_power_status(struct device *cdev,
598 struct device_attribute *attr,
599 const char *buf, size_t count)
601 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
602 struct enclosure_component *ecomp = to_enclosure_component(cdev);
603 int val;
605 if (strncmp(buf, "on", 2) == 0 &&
606 (buf[2] == '\n' || buf[2] == '\0'))
607 val = 1;
608 else if (strncmp(buf, "off", 3) == 0 &&
609 (buf[3] == '\n' || buf[3] == '\0'))
610 val = 0;
611 else
612 return -EINVAL;
614 if (edev->cb->set_power_status)
615 edev->cb->set_power_status(edev, ecomp, val);
616 return count;
619 static ssize_t get_component_type(struct device *cdev,
620 struct device_attribute *attr, char *buf)
622 struct enclosure_component *ecomp = to_enclosure_component(cdev);
624 return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
627 static ssize_t get_component_slot(struct device *cdev,
628 struct device_attribute *attr, char *buf)
630 struct enclosure_component *ecomp = to_enclosure_component(cdev);
631 int slot;
633 /* if the enclosure does not override then use 'number' as a stand-in */
634 if (ecomp->slot >= 0)
635 slot = ecomp->slot;
636 else
637 slot = ecomp->number;
639 return snprintf(buf, 40, "%d\n", slot);
642 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
643 set_component_fault);
644 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
645 set_component_status);
646 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
647 set_component_active);
648 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
649 set_component_locate);
650 static DEVICE_ATTR(power_status, S_IRUGO | S_IWUSR, get_component_power_status,
651 set_component_power_status);
652 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
653 static DEVICE_ATTR(slot, S_IRUGO, get_component_slot, NULL);
655 static struct attribute *enclosure_component_attrs[] = {
656 &dev_attr_fault.attr,
657 &dev_attr_status.attr,
658 &dev_attr_active.attr,
659 &dev_attr_locate.attr,
660 &dev_attr_power_status.attr,
661 &dev_attr_type.attr,
662 &dev_attr_slot.attr,
663 NULL
665 ATTRIBUTE_GROUPS(enclosure_component);
667 static int __init enclosure_init(void)
669 return class_register(&enclosure_class);
672 static void __exit enclosure_exit(void)
674 class_unregister(&enclosure_class);
677 module_init(enclosure_init);
678 module_exit(enclosure_exit);
680 MODULE_AUTHOR("James Bottomley");
681 MODULE_DESCRIPTION("Enclosure Services");
682 MODULE_LICENSE("GPL v2");