[media] docs-rst: fix cec bad cross-references
[linux-2.6/btrfs-unstable.git] / drivers / misc / enclosure.c
blob65fed7146e9bac2a407df1c05710d6a6eb75e6c4
1 /*
2 * Enclosure Services
4 * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
6 **-----------------------------------------------------------------------------
7 **
8 ** This program is free software; you can redistribute it and/or
9 ** modify it under the terms of the GNU General Public License
10 ** version 2 as published by the Free Software Foundation.
12 ** This program is distributed in the hope that it will be useful,
13 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
14 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 ** GNU General Public License for more details.
17 ** You should have received a copy of the GNU General Public License
18 ** along with this program; if not, write to the Free Software
19 ** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21 **-----------------------------------------------------------------------------
23 #include <linux/device.h>
24 #include <linux/enclosure.h>
25 #include <linux/err.h>
26 #include <linux/list.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/mutex.h>
30 #include <linux/slab.h>
32 static LIST_HEAD(container_list);
33 static DEFINE_MUTEX(container_list_lock);
34 static struct class enclosure_class;
36 /**
37 * enclosure_find - find an enclosure given a parent device
38 * @dev: the parent to match against
39 * @start: Optional enclosure device to start from (NULL if none)
41 * Looks through the list of registered enclosures to find all those
42 * with @dev as a parent. Returns NULL if no enclosure is
43 * found. @start can be used as a starting point to obtain multiple
44 * enclosures per parent (should begin with NULL and then be set to
45 * each returned enclosure device). Obtains a reference to the
46 * enclosure class device which must be released with device_put().
47 * If @start is not NULL, a reference must be taken on it which is
48 * released before returning (this allows a loop through all
49 * enclosures to exit with only the reference on the enclosure of
50 * interest held). Note that the @dev may correspond to the actual
51 * device housing the enclosure, in which case no iteration via @start
52 * is required.
54 struct enclosure_device *enclosure_find(struct device *dev,
55 struct enclosure_device *start)
57 struct enclosure_device *edev;
59 mutex_lock(&container_list_lock);
60 edev = list_prepare_entry(start, &container_list, node);
61 if (start)
62 put_device(&start->edev);
64 list_for_each_entry_continue(edev, &container_list, node) {
65 struct device *parent = edev->edev.parent;
66 /* parent might not be immediate, so iterate up to
67 * the root of the tree if necessary */
68 while (parent) {
69 if (parent == dev) {
70 get_device(&edev->edev);
71 mutex_unlock(&container_list_lock);
72 return edev;
74 parent = parent->parent;
77 mutex_unlock(&container_list_lock);
79 return NULL;
81 EXPORT_SYMBOL_GPL(enclosure_find);
83 /**
84 * enclosure_for_each_device - calls a function for each enclosure
85 * @fn: the function to call
86 * @data: the data to pass to each call
88 * Loops over all the enclosures calling the function.
90 * Note, this function uses a mutex which will be held across calls to
91 * @fn, so it must have non atomic context, and @fn may (although it
92 * should not) sleep or otherwise cause the mutex to be held for
93 * indefinite periods
95 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
96 void *data)
98 int error = 0;
99 struct enclosure_device *edev;
101 mutex_lock(&container_list_lock);
102 list_for_each_entry(edev, &container_list, node) {
103 error = fn(edev, data);
104 if (error)
105 break;
107 mutex_unlock(&container_list_lock);
109 return error;
111 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
114 * enclosure_register - register device as an enclosure
116 * @dev: device containing the enclosure
117 * @components: number of components in the enclosure
119 * This sets up the device for being an enclosure. Note that @dev does
120 * not have to be a dedicated enclosure device. It may be some other type
121 * of device that additionally responds to enclosure services
123 struct enclosure_device *
124 enclosure_register(struct device *dev, const char *name, int components,
125 struct enclosure_component_callbacks *cb)
127 struct enclosure_device *edev =
128 kzalloc(sizeof(struct enclosure_device) +
129 sizeof(struct enclosure_component)*components,
130 GFP_KERNEL);
131 int err, i;
133 BUG_ON(!cb);
135 if (!edev)
136 return ERR_PTR(-ENOMEM);
138 edev->components = components;
140 edev->edev.class = &enclosure_class;
141 edev->edev.parent = get_device(dev);
142 edev->cb = cb;
143 dev_set_name(&edev->edev, "%s", name);
144 err = device_register(&edev->edev);
145 if (err)
146 goto err;
148 for (i = 0; i < components; i++) {
149 edev->component[i].number = -1;
150 edev->component[i].slot = -1;
151 edev->component[i].power_status = 1;
154 mutex_lock(&container_list_lock);
155 list_add_tail(&edev->node, &container_list);
156 mutex_unlock(&container_list_lock);
158 return edev;
160 err:
161 put_device(edev->edev.parent);
162 kfree(edev);
163 return ERR_PTR(err);
165 EXPORT_SYMBOL_GPL(enclosure_register);
167 static struct enclosure_component_callbacks enclosure_null_callbacks;
170 * enclosure_unregister - remove an enclosure
172 * @edev: the registered enclosure to remove;
174 void enclosure_unregister(struct enclosure_device *edev)
176 int i;
178 mutex_lock(&container_list_lock);
179 list_del(&edev->node);
180 mutex_unlock(&container_list_lock);
182 for (i = 0; i < edev->components; i++)
183 if (edev->component[i].number != -1)
184 device_unregister(&edev->component[i].cdev);
186 /* prevent any callbacks into service user */
187 edev->cb = &enclosure_null_callbacks;
188 device_unregister(&edev->edev);
190 EXPORT_SYMBOL_GPL(enclosure_unregister);
192 #define ENCLOSURE_NAME_SIZE 64
193 #define COMPONENT_NAME_SIZE 64
195 static void enclosure_link_name(struct enclosure_component *cdev, char *name)
197 strcpy(name, "enclosure_device:");
198 strcat(name, dev_name(&cdev->cdev));
201 static void enclosure_remove_links(struct enclosure_component *cdev)
203 char name[ENCLOSURE_NAME_SIZE];
205 enclosure_link_name(cdev, name);
208 * In odd circumstances, like multipath devices, something else may
209 * already have removed the links, so check for this condition first.
211 if (cdev->dev->kobj.sd)
212 sysfs_remove_link(&cdev->dev->kobj, name);
214 if (cdev->cdev.kobj.sd)
215 sysfs_remove_link(&cdev->cdev.kobj, "device");
218 static int enclosure_add_links(struct enclosure_component *cdev)
220 int error;
221 char name[ENCLOSURE_NAME_SIZE];
223 error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
224 if (error)
225 return error;
227 enclosure_link_name(cdev, name);
228 error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
229 if (error)
230 sysfs_remove_link(&cdev->cdev.kobj, "device");
232 return error;
235 static void enclosure_release(struct device *cdev)
237 struct enclosure_device *edev = to_enclosure_device(cdev);
239 put_device(cdev->parent);
240 kfree(edev);
243 static void enclosure_component_release(struct device *dev)
245 struct enclosure_component *cdev = to_enclosure_component(dev);
247 if (cdev->dev) {
248 enclosure_remove_links(cdev);
249 put_device(cdev->dev);
251 put_device(dev->parent);
254 static struct enclosure_component *
255 enclosure_component_find_by_name(struct enclosure_device *edev,
256 const char *name)
258 int i;
259 const char *cname;
260 struct enclosure_component *ecomp;
262 if (!edev || !name || !name[0])
263 return NULL;
265 for (i = 0; i < edev->components; i++) {
266 ecomp = &edev->component[i];
267 cname = dev_name(&ecomp->cdev);
268 if (ecomp->number != -1 &&
269 cname && cname[0] &&
270 !strcmp(cname, name))
271 return ecomp;
274 return NULL;
277 static const struct attribute_group *enclosure_component_groups[];
280 * enclosure_component_alloc - prepare a new enclosure component
281 * @edev: the enclosure to add the component
282 * @num: the device number
283 * @type: the type of component being added
284 * @name: an optional name to appear in sysfs (leave NULL if none)
286 * The name is optional for enclosures that give their components a unique
287 * name. If not, leave the field NULL and a name will be assigned.
289 * Returns a pointer to the enclosure component or an error.
291 struct enclosure_component *
292 enclosure_component_alloc(struct enclosure_device *edev,
293 unsigned int number,
294 enum enclosure_component_type type,
295 const char *name)
297 struct enclosure_component *ecomp;
298 struct device *cdev;
299 int i;
300 char newname[COMPONENT_NAME_SIZE];
302 if (number >= edev->components)
303 return ERR_PTR(-EINVAL);
305 ecomp = &edev->component[number];
307 if (ecomp->number != -1)
308 return ERR_PTR(-EINVAL);
310 ecomp->type = type;
311 ecomp->number = number;
312 cdev = &ecomp->cdev;
313 cdev->parent = get_device(&edev->edev);
315 if (name && name[0]) {
316 /* Some hardware (e.g. enclosure in RX300 S6) has components
317 * with non unique names. Registering duplicates in sysfs
318 * will lead to warnings during bootup. So make the names
319 * unique by appending consecutive numbers -1, -2, ... */
320 i = 1;
321 snprintf(newname, COMPONENT_NAME_SIZE,
322 "%s", name);
323 while (enclosure_component_find_by_name(edev, newname))
324 snprintf(newname, COMPONENT_NAME_SIZE,
325 "%s-%i", name, i++);
326 dev_set_name(cdev, "%s", newname);
327 } else
328 dev_set_name(cdev, "%u", number);
330 cdev->release = enclosure_component_release;
331 cdev->groups = enclosure_component_groups;
333 return ecomp;
335 EXPORT_SYMBOL_GPL(enclosure_component_alloc);
338 * enclosure_component_register - publishes an initialized enclosure component
339 * @ecomp: component to add
341 * Returns 0 on successful registration, releases the component otherwise
343 int enclosure_component_register(struct enclosure_component *ecomp)
345 struct device *cdev;
346 int err;
348 cdev = &ecomp->cdev;
349 err = device_register(cdev);
350 if (err) {
351 ecomp->number = -1;
352 put_device(cdev);
353 return err;
356 return 0;
358 EXPORT_SYMBOL_GPL(enclosure_component_register);
361 * enclosure_add_device - add a device as being part of an enclosure
362 * @edev: the enclosure device being added to.
363 * @num: the number of the component
364 * @dev: the device being added
366 * Declares a real device to reside in slot (or identifier) @num of an
367 * enclosure. This will cause the relevant sysfs links to appear.
368 * This function may also be used to change a device associated with
369 * an enclosure without having to call enclosure_remove_device() in
370 * between.
372 * Returns zero on success or an error.
374 int enclosure_add_device(struct enclosure_device *edev, int component,
375 struct device *dev)
377 struct enclosure_component *cdev;
379 if (!edev || component >= edev->components)
380 return -EINVAL;
382 cdev = &edev->component[component];
384 if (cdev->dev == dev)
385 return -EEXIST;
387 if (cdev->dev)
388 enclosure_remove_links(cdev);
390 put_device(cdev->dev);
391 cdev->dev = get_device(dev);
392 return enclosure_add_links(cdev);
394 EXPORT_SYMBOL_GPL(enclosure_add_device);
397 * enclosure_remove_device - remove a device from an enclosure
398 * @edev: the enclosure device
399 * @num: the number of the component to remove
401 * Returns zero on success or an error.
404 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
406 struct enclosure_component *cdev;
407 int i;
409 if (!edev || !dev)
410 return -EINVAL;
412 for (i = 0; i < edev->components; i++) {
413 cdev = &edev->component[i];
414 if (cdev->dev == dev) {
415 enclosure_remove_links(cdev);
416 device_del(&cdev->cdev);
417 put_device(dev);
418 cdev->dev = NULL;
419 return device_add(&cdev->cdev);
422 return -ENODEV;
424 EXPORT_SYMBOL_GPL(enclosure_remove_device);
427 * sysfs pieces below
430 static ssize_t components_show(struct device *cdev,
431 struct device_attribute *attr, char *buf)
433 struct enclosure_device *edev = to_enclosure_device(cdev);
435 return snprintf(buf, 40, "%d\n", edev->components);
437 static DEVICE_ATTR_RO(components);
439 static ssize_t id_show(struct device *cdev,
440 struct device_attribute *attr,
441 char *buf)
443 struct enclosure_device *edev = to_enclosure_device(cdev);
445 if (edev->cb->show_id)
446 return edev->cb->show_id(edev, buf);
447 return -EINVAL;
449 static DEVICE_ATTR_RO(id);
451 static struct attribute *enclosure_class_attrs[] = {
452 &dev_attr_components.attr,
453 &dev_attr_id.attr,
454 NULL,
456 ATTRIBUTE_GROUPS(enclosure_class);
458 static struct class enclosure_class = {
459 .name = "enclosure",
460 .owner = THIS_MODULE,
461 .dev_release = enclosure_release,
462 .dev_groups = enclosure_class_groups,
465 static const char *const enclosure_status [] = {
466 [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
467 [ENCLOSURE_STATUS_OK] = "OK",
468 [ENCLOSURE_STATUS_CRITICAL] = "critical",
469 [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
470 [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
471 [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
472 [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
473 [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
474 [ENCLOSURE_STATUS_MAX] = NULL,
477 static const char *const enclosure_type [] = {
478 [ENCLOSURE_COMPONENT_DEVICE] = "device",
479 [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
482 static ssize_t get_component_fault(struct device *cdev,
483 struct device_attribute *attr, char *buf)
485 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
486 struct enclosure_component *ecomp = to_enclosure_component(cdev);
488 if (edev->cb->get_fault)
489 edev->cb->get_fault(edev, ecomp);
490 return snprintf(buf, 40, "%d\n", ecomp->fault);
493 static ssize_t set_component_fault(struct device *cdev,
494 struct device_attribute *attr,
495 const char *buf, size_t count)
497 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
498 struct enclosure_component *ecomp = to_enclosure_component(cdev);
499 int val = simple_strtoul(buf, NULL, 0);
501 if (edev->cb->set_fault)
502 edev->cb->set_fault(edev, ecomp, val);
503 return count;
506 static ssize_t get_component_status(struct device *cdev,
507 struct device_attribute *attr,char *buf)
509 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
510 struct enclosure_component *ecomp = to_enclosure_component(cdev);
512 if (edev->cb->get_status)
513 edev->cb->get_status(edev, ecomp);
514 return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
517 static ssize_t set_component_status(struct device *cdev,
518 struct device_attribute *attr,
519 const char *buf, size_t count)
521 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
522 struct enclosure_component *ecomp = to_enclosure_component(cdev);
523 int i;
525 for (i = 0; enclosure_status[i]; i++) {
526 if (strncmp(buf, enclosure_status[i],
527 strlen(enclosure_status[i])) == 0 &&
528 (buf[strlen(enclosure_status[i])] == '\n' ||
529 buf[strlen(enclosure_status[i])] == '\0'))
530 break;
533 if (enclosure_status[i] && edev->cb->set_status) {
534 edev->cb->set_status(edev, ecomp, i);
535 return count;
536 } else
537 return -EINVAL;
540 static ssize_t get_component_active(struct device *cdev,
541 struct device_attribute *attr, char *buf)
543 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
544 struct enclosure_component *ecomp = to_enclosure_component(cdev);
546 if (edev->cb->get_active)
547 edev->cb->get_active(edev, ecomp);
548 return snprintf(buf, 40, "%d\n", ecomp->active);
551 static ssize_t set_component_active(struct device *cdev,
552 struct device_attribute *attr,
553 const char *buf, size_t count)
555 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
556 struct enclosure_component *ecomp = to_enclosure_component(cdev);
557 int val = simple_strtoul(buf, NULL, 0);
559 if (edev->cb->set_active)
560 edev->cb->set_active(edev, ecomp, val);
561 return count;
564 static ssize_t get_component_locate(struct device *cdev,
565 struct device_attribute *attr, char *buf)
567 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
568 struct enclosure_component *ecomp = to_enclosure_component(cdev);
570 if (edev->cb->get_locate)
571 edev->cb->get_locate(edev, ecomp);
572 return snprintf(buf, 40, "%d\n", ecomp->locate);
575 static ssize_t set_component_locate(struct device *cdev,
576 struct device_attribute *attr,
577 const char *buf, size_t count)
579 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
580 struct enclosure_component *ecomp = to_enclosure_component(cdev);
581 int val = simple_strtoul(buf, NULL, 0);
583 if (edev->cb->set_locate)
584 edev->cb->set_locate(edev, ecomp, val);
585 return count;
588 static ssize_t get_component_power_status(struct device *cdev,
589 struct device_attribute *attr,
590 char *buf)
592 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
593 struct enclosure_component *ecomp = to_enclosure_component(cdev);
595 if (edev->cb->get_power_status)
596 edev->cb->get_power_status(edev, ecomp);
597 return snprintf(buf, 40, "%s\n", ecomp->power_status ? "on" : "off");
600 static ssize_t set_component_power_status(struct device *cdev,
601 struct device_attribute *attr,
602 const char *buf, size_t count)
604 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
605 struct enclosure_component *ecomp = to_enclosure_component(cdev);
606 int val;
608 if (strncmp(buf, "on", 2) == 0 &&
609 (buf[2] == '\n' || buf[2] == '\0'))
610 val = 1;
611 else if (strncmp(buf, "off", 3) == 0 &&
612 (buf[3] == '\n' || buf[3] == '\0'))
613 val = 0;
614 else
615 return -EINVAL;
617 if (edev->cb->set_power_status)
618 edev->cb->set_power_status(edev, ecomp, val);
619 return count;
622 static ssize_t get_component_type(struct device *cdev,
623 struct device_attribute *attr, char *buf)
625 struct enclosure_component *ecomp = to_enclosure_component(cdev);
627 return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
630 static ssize_t get_component_slot(struct device *cdev,
631 struct device_attribute *attr, char *buf)
633 struct enclosure_component *ecomp = to_enclosure_component(cdev);
634 int slot;
636 /* if the enclosure does not override then use 'number' as a stand-in */
637 if (ecomp->slot >= 0)
638 slot = ecomp->slot;
639 else
640 slot = ecomp->number;
642 return snprintf(buf, 40, "%d\n", slot);
645 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
646 set_component_fault);
647 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
648 set_component_status);
649 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
650 set_component_active);
651 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
652 set_component_locate);
653 static DEVICE_ATTR(power_status, S_IRUGO | S_IWUSR, get_component_power_status,
654 set_component_power_status);
655 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
656 static DEVICE_ATTR(slot, S_IRUGO, get_component_slot, NULL);
658 static struct attribute *enclosure_component_attrs[] = {
659 &dev_attr_fault.attr,
660 &dev_attr_status.attr,
661 &dev_attr_active.attr,
662 &dev_attr_locate.attr,
663 &dev_attr_power_status.attr,
664 &dev_attr_type.attr,
665 &dev_attr_slot.attr,
666 NULL
668 ATTRIBUTE_GROUPS(enclosure_component);
670 static int __init enclosure_init(void)
672 int err;
674 err = class_register(&enclosure_class);
675 if (err)
676 return err;
678 return 0;
681 static void __exit enclosure_exit(void)
683 class_unregister(&enclosure_class);
686 module_init(enclosure_init);
687 module_exit(enclosure_exit);
689 MODULE_AUTHOR("James Bottomley");
690 MODULE_DESCRIPTION("Enclosure Services");
691 MODULE_LICENSE("GPL v2");