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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Software nodes for the firmware node framework.
4 *
5 * Copyright (C) 2018, Intel Corporation
6 * Author: Heikki Krogerus <heikki.krogerus@linux.intel.com>
7 */
8
9#include <linux/container_of.h>
10#include <linux/device.h>
11#include <linux/err.h>
12#include <linux/export.h>
13#include <linux/idr.h>
14#include <linux/init.h>
15#include <linux/kobject.h>
16#include <linux/kstrtox.h>
17#include <linux/list.h>
18#include <linux/property.h>
19#include <linux/slab.h>
20#include <linux/spinlock.h>
21#include <linux/string.h>
22#include <linux/sysfs.h>
23#include <linux/types.h>
24
25#include "base.h"
26
27struct swnode {
28 struct kobject kobj;
29 struct fwnode_handle fwnode;
30 const struct software_node *node;
31 int id;
32
33 /* hierarchy */
34 struct ida child_ids;
35 struct list_head entry;
36 struct list_head children;
37 struct swnode *parent;
38
39 unsigned int allocated:1;
40 unsigned int managed:1;
41};
42
43static DEFINE_IDA(swnode_root_ids);
44static struct kset *swnode_kset;
45
46#define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)
47
48static const struct fwnode_operations software_node_ops;
49
50bool is_software_node(const struct fwnode_handle *fwnode)
51{
52 return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
53}
54EXPORT_SYMBOL_GPL(is_software_node);
55
56#define to_swnode(__fwnode) \
57 ({ \
58 typeof(__fwnode) __to_swnode_fwnode = __fwnode; \
59 \
60 is_software_node(__to_swnode_fwnode) ? \
61 container_of(__to_swnode_fwnode, \
62 struct swnode, fwnode) : NULL; \
63 })
64
65static inline struct swnode *dev_to_swnode(struct device *dev)
66{
67 struct fwnode_handle *fwnode = dev_fwnode(dev);
68
69 if (!fwnode)
70 return NULL;
71
72 if (!is_software_node(fwnode))
73 fwnode = fwnode->secondary;
74
75 return to_swnode(fwnode);
76}
77
78static struct swnode *
79software_node_to_swnode(const struct software_node *node)
80{
81 struct swnode *swnode = NULL;
82 struct kobject *k;
83
84 if (!node)
85 return NULL;
86
87 spin_lock(&swnode_kset->list_lock);
88
89 list_for_each_entry(k, &swnode_kset->list, entry) {
90 swnode = kobj_to_swnode(k);
91 if (swnode->node == node)
92 break;
93 swnode = NULL;
94 }
95
96 spin_unlock(&swnode_kset->list_lock);
97
98 return swnode;
99}
100
101const struct software_node *to_software_node(const struct fwnode_handle *fwnode)
102{
103 const struct swnode *swnode = to_swnode(fwnode);
104
105 return swnode ? swnode->node : NULL;
106}
107EXPORT_SYMBOL_GPL(to_software_node);
108
109struct fwnode_handle *software_node_fwnode(const struct software_node *node)
110{
111 struct swnode *swnode = software_node_to_swnode(node);
112
113 return swnode ? &swnode->fwnode : NULL;
114}
115EXPORT_SYMBOL_GPL(software_node_fwnode);
116
117/* -------------------------------------------------------------------------- */
118/* property_entry processing */
119
120static const struct property_entry *
121property_entry_get(const struct property_entry *prop, const char *name)
122{
123 if (!prop)
124 return NULL;
125
126 for (; prop->name; prop++)
127 if (!strcmp(name, prop->name))
128 return prop;
129
130 return NULL;
131}
132
133static const void *property_get_pointer(const struct property_entry *prop)
134{
135 if (!prop->length)
136 return NULL;
137
138 return prop->is_inline ? &prop->value : prop->pointer;
139}
140
141static const void *property_entry_find(const struct property_entry *props,
142 const char *propname, size_t length)
143{
144 const struct property_entry *prop;
145 const void *pointer;
146
147 prop = property_entry_get(props, propname);
148 if (!prop)
149 return ERR_PTR(-EINVAL);
150 pointer = property_get_pointer(prop);
151 if (!pointer)
152 return ERR_PTR(-ENODATA);
153 if (length > prop->length)
154 return ERR_PTR(-EOVERFLOW);
155 return pointer;
156}
157
158static int
159property_entry_count_elems_of_size(const struct property_entry *props,
160 const char *propname, size_t length)
161{
162 const struct property_entry *prop;
163
164 prop = property_entry_get(props, propname);
165 if (!prop)
166 return -EINVAL;
167
168 return prop->length / length;
169}
170
171static int property_entry_read_int_array(const struct property_entry *props,
172 const char *name,
173 unsigned int elem_size, void *val,
174 size_t nval)
175{
176 const void *pointer;
177 size_t length;
178
179 if (!val)
180 return property_entry_count_elems_of_size(props, name,
181 elem_size);
182
183 if (!is_power_of_2(elem_size) || elem_size > sizeof(u64))
184 return -ENXIO;
185
186 length = nval * elem_size;
187
188 pointer = property_entry_find(props, name, length);
189 if (IS_ERR(pointer))
190 return PTR_ERR(pointer);
191
192 memcpy(val, pointer, length);
193 return 0;
194}
195
196static int property_entry_read_string_array(const struct property_entry *props,
197 const char *propname,
198 const char **strings, size_t nval)
199{
200 const void *pointer;
201 size_t length;
202 int array_len;
203
204 /* Find out the array length. */
205 array_len = property_entry_count_elems_of_size(props, propname,
206 sizeof(const char *));
207 if (array_len < 0)
208 return array_len;
209
210 /* Return how many there are if strings is NULL. */
211 if (!strings)
212 return array_len;
213
214 array_len = min_t(size_t, nval, array_len);
215 length = array_len * sizeof(*strings);
216
217 pointer = property_entry_find(props, propname, length);
218 if (IS_ERR(pointer))
219 return PTR_ERR(pointer);
220
221 memcpy(strings, pointer, length);
222
223 return array_len;
224}
225
226static void property_entry_free_data(const struct property_entry *p)
227{
228 const char * const *src_str;
229 size_t i, nval;
230
231 if (p->type == DEV_PROP_STRING) {
232 src_str = property_get_pointer(p);
233 nval = p->length / sizeof(*src_str);
234 for (i = 0; i < nval; i++)
235 kfree(src_str[i]);
236 }
237
238 if (!p->is_inline)
239 kfree(p->pointer);
240
241 kfree(p->name);
242}
243
244static bool property_copy_string_array(const char **dst_ptr,
245 const char * const *src_ptr,
246 size_t nval)
247{
248 int i;
249
250 for (i = 0; i < nval; i++) {
251 dst_ptr[i] = kstrdup(src_ptr[i], GFP_KERNEL);
252 if (!dst_ptr[i] && src_ptr[i]) {
253 while (--i >= 0)
254 kfree(dst_ptr[i]);
255 return false;
256 }
257 }
258
259 return true;
260}
261
262static int property_entry_copy_data(struct property_entry *dst,
263 const struct property_entry *src)
264{
265 const void *pointer = property_get_pointer(src);
266 void *dst_ptr;
267 size_t nval;
268
269 /*
270 * Properties with no data should not be marked as stored
271 * out of line.
272 */
273 if (!src->is_inline && !src->length)
274 return -ENODATA;
275
276 /*
277 * Reference properties are never stored inline as
278 * they are too big.
279 */
280 if (src->type == DEV_PROP_REF && src->is_inline)
281 return -EINVAL;
282
283 if (src->length <= sizeof(dst->value)) {
284 dst_ptr = &dst->value;
285 dst->is_inline = true;
286 } else {
287 dst_ptr = kmalloc(src->length, GFP_KERNEL);
288 if (!dst_ptr)
289 return -ENOMEM;
290 dst->pointer = dst_ptr;
291 }
292
293 if (src->type == DEV_PROP_STRING) {
294 nval = src->length / sizeof(const char *);
295 if (!property_copy_string_array(dst_ptr, pointer, nval)) {
296 if (!dst->is_inline)
297 kfree(dst->pointer);
298 return -ENOMEM;
299 }
300 } else {
301 memcpy(dst_ptr, pointer, src->length);
302 }
303
304 dst->length = src->length;
305 dst->type = src->type;
306 dst->name = kstrdup(src->name, GFP_KERNEL);
307 if (!dst->name) {
308 property_entry_free_data(dst);
309 return -ENOMEM;
310 }
311
312 return 0;
313}
314
315/**
316 * property_entries_dup - duplicate array of properties
317 * @properties: array of properties to copy
318 *
319 * This function creates a deep copy of the given NULL-terminated array
320 * of property entries.
321 */
322struct property_entry *
323property_entries_dup(const struct property_entry *properties)
324{
325 struct property_entry *p;
326 int i, n = 0;
327 int ret;
328
329 if (!properties)
330 return NULL;
331
332 while (properties[n].name)
333 n++;
334
335 p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
336 if (!p)
337 return ERR_PTR(-ENOMEM);
338
339 for (i = 0; i < n; i++) {
340 ret = property_entry_copy_data(&p[i], &properties[i]);
341 if (ret) {
342 while (--i >= 0)
343 property_entry_free_data(&p[i]);
344 kfree(p);
345 return ERR_PTR(ret);
346 }
347 }
348
349 return p;
350}
351EXPORT_SYMBOL_GPL(property_entries_dup);
352
353/**
354 * property_entries_free - free previously allocated array of properties
355 * @properties: array of properties to destroy
356 *
357 * This function frees given NULL-terminated array of property entries,
358 * along with their data.
359 */
360void property_entries_free(const struct property_entry *properties)
361{
362 const struct property_entry *p;
363
364 if (!properties)
365 return;
366
367 for (p = properties; p->name; p++)
368 property_entry_free_data(p);
369
370 kfree(properties);
371}
372EXPORT_SYMBOL_GPL(property_entries_free);
373
374/* -------------------------------------------------------------------------- */
375/* fwnode operations */
376
377static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode)
378{
379 struct swnode *swnode = to_swnode(fwnode);
380
381 kobject_get(&swnode->kobj);
382
383 return &swnode->fwnode;
384}
385
386static void software_node_put(struct fwnode_handle *fwnode)
387{
388 struct swnode *swnode = to_swnode(fwnode);
389
390 kobject_put(&swnode->kobj);
391}
392
393static bool software_node_property_present(const struct fwnode_handle *fwnode,
394 const char *propname)
395{
396 struct swnode *swnode = to_swnode(fwnode);
397
398 return !!property_entry_get(swnode->node->properties, propname);
399}
400
401static int software_node_read_int_array(const struct fwnode_handle *fwnode,
402 const char *propname,
403 unsigned int elem_size, void *val,
404 size_t nval)
405{
406 struct swnode *swnode = to_swnode(fwnode);
407
408 return property_entry_read_int_array(swnode->node->properties, propname,
409 elem_size, val, nval);
410}
411
412static int software_node_read_string_array(const struct fwnode_handle *fwnode,
413 const char *propname,
414 const char **val, size_t nval)
415{
416 struct swnode *swnode = to_swnode(fwnode);
417
418 return property_entry_read_string_array(swnode->node->properties,
419 propname, val, nval);
420}
421
422static const char *
423software_node_get_name(const struct fwnode_handle *fwnode)
424{
425 const struct swnode *swnode = to_swnode(fwnode);
426
427 return kobject_name(&swnode->kobj);
428}
429
430static const char *
431software_node_get_name_prefix(const struct fwnode_handle *fwnode)
432{
433 struct fwnode_handle *parent;
434 const char *prefix;
435
436 parent = fwnode_get_parent(fwnode);
437 if (!parent)
438 return "";
439
440 /* Figure out the prefix from the parents. */
441 while (is_software_node(parent))
442 parent = fwnode_get_next_parent(parent);
443
444 prefix = fwnode_get_name_prefix(parent);
445 fwnode_handle_put(parent);
446
447 /* Guess something if prefix was NULL. */
448 return prefix ?: "/";
449}
450
451static struct fwnode_handle *
452software_node_get_parent(const struct fwnode_handle *fwnode)
453{
454 struct swnode *swnode = to_swnode(fwnode);
455
456 if (!swnode || !swnode->parent)
457 return NULL;
458
459 return fwnode_handle_get(&swnode->parent->fwnode);
460}
461
462static struct fwnode_handle *
463software_node_get_next_child(const struct fwnode_handle *fwnode,
464 struct fwnode_handle *child)
465{
466 struct swnode *p = to_swnode(fwnode);
467 struct swnode *c = to_swnode(child);
468
469 if (!p || list_empty(&p->children) ||
470 (c && list_is_last(&c->entry, &p->children))) {
471 fwnode_handle_put(child);
472 return NULL;
473 }
474
475 if (c)
476 c = list_next_entry(c, entry);
477 else
478 c = list_first_entry(&p->children, struct swnode, entry);
479
480 fwnode_handle_put(child);
481 return fwnode_handle_get(&c->fwnode);
482}
483
484static struct fwnode_handle *
485software_node_get_named_child_node(const struct fwnode_handle *fwnode,
486 const char *childname)
487{
488 struct swnode *swnode = to_swnode(fwnode);
489 struct swnode *child;
490
491 if (!swnode || list_empty(&swnode->children))
492 return NULL;
493
494 list_for_each_entry(child, &swnode->children, entry) {
495 if (!strcmp(childname, kobject_name(&child->kobj))) {
496 kobject_get(&child->kobj);
497 return &child->fwnode;
498 }
499 }
500 return NULL;
501}
502
503static int
504software_node_get_reference_args(const struct fwnode_handle *fwnode,
505 const char *propname, const char *nargs_prop,
506 unsigned int nargs, unsigned int index,
507 struct fwnode_reference_args *args)
508{
509 struct swnode *swnode = to_swnode(fwnode);
510 const struct software_node_ref_args *ref_array;
511 const struct software_node_ref_args *ref;
512 const struct property_entry *prop;
513 struct fwnode_handle *refnode;
514 u32 nargs_prop_val;
515 int error;
516 int i;
517
518 prop = property_entry_get(swnode->node->properties, propname);
519 if (!prop)
520 return -ENOENT;
521
522 if (prop->type != DEV_PROP_REF)
523 return -EINVAL;
524
525 /*
526 * We expect that references are never stored inline, even
527 * single ones, as they are too big.
528 */
529 if (prop->is_inline)
530 return -EINVAL;
531
532 if (index * sizeof(*ref) >= prop->length)
533 return -ENOENT;
534
535 ref_array = prop->pointer;
536 ref = &ref_array[index];
537
538 refnode = software_node_fwnode(ref->node);
539 if (!refnode)
540 return -ENOENT;
541
542 if (nargs_prop) {
543 error = property_entry_read_int_array(ref->node->properties,
544 nargs_prop, sizeof(u32),
545 &nargs_prop_val, 1);
546 if (error)
547 return error;
548
549 nargs = nargs_prop_val;
550 }
551
552 if (nargs > NR_FWNODE_REFERENCE_ARGS)
553 return -EINVAL;
554
555 if (!args)
556 return 0;
557
558 args->fwnode = software_node_get(refnode);
559 args->nargs = nargs;
560
561 for (i = 0; i < nargs; i++)
562 args->args[i] = ref->args[i];
563
564 return 0;
565}
566
567static struct fwnode_handle *
568swnode_graph_find_next_port(const struct fwnode_handle *parent,
569 struct fwnode_handle *port)
570{
571 struct fwnode_handle *old = port;
572
573 while ((port = software_node_get_next_child(parent, old))) {
574 /*
575 * fwnode ports have naming style "port@", so we search for any
576 * children that follow that convention.
577 */
578 if (!strncmp(to_swnode(port)->node->name, "port@",
579 strlen("port@")))
580 return port;
581 old = port;
582 }
583
584 return NULL;
585}
586
587static struct fwnode_handle *
588software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
589 struct fwnode_handle *endpoint)
590{
591 struct swnode *swnode = to_swnode(fwnode);
592 struct fwnode_handle *parent;
593 struct fwnode_handle *port;
594
595 if (!swnode)
596 return NULL;
597
598 if (endpoint) {
599 port = software_node_get_parent(endpoint);
600 parent = software_node_get_parent(port);
601 } else {
602 parent = software_node_get_named_child_node(fwnode, "ports");
603 if (!parent)
604 parent = software_node_get(&swnode->fwnode);
605
606 port = swnode_graph_find_next_port(parent, NULL);
607 }
608
609 for (; port; port = swnode_graph_find_next_port(parent, port)) {
610 endpoint = software_node_get_next_child(port, endpoint);
611 if (endpoint) {
612 fwnode_handle_put(port);
613 break;
614 }
615 }
616
617 fwnode_handle_put(parent);
618
619 return endpoint;
620}
621
622static struct fwnode_handle *
623software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
624{
625 struct swnode *swnode = to_swnode(fwnode);
626 const struct software_node_ref_args *ref;
627 const struct property_entry *prop;
628
629 if (!swnode)
630 return NULL;
631
632 prop = property_entry_get(swnode->node->properties, "remote-endpoint");
633 if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
634 return NULL;
635
636 ref = prop->pointer;
637
638 return software_node_get(software_node_fwnode(ref[0].node));
639}
640
641static struct fwnode_handle *
642software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
643{
644 struct swnode *swnode = to_swnode(fwnode);
645
646 swnode = swnode->parent;
647 if (swnode && !strcmp(swnode->node->name, "ports"))
648 swnode = swnode->parent;
649
650 return swnode ? software_node_get(&swnode->fwnode) : NULL;
651}
652
653static int
654software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
655 struct fwnode_endpoint *endpoint)
656{
657 struct swnode *swnode = to_swnode(fwnode);
658 const char *parent_name = swnode->parent->node->name;
659 int ret;
660
661 if (strlen("port@") >= strlen(parent_name) ||
662 strncmp(parent_name, "port@", strlen("port@")))
663 return -EINVAL;
664
665 /* Ports have naming style "port@n", we need to select the n */
666 ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port);
667 if (ret)
668 return ret;
669
670 endpoint->id = swnode->id;
671 endpoint->local_fwnode = fwnode;
672
673 return 0;
674}
675
676static const struct fwnode_operations software_node_ops = {
677 .get = software_node_get,
678 .put = software_node_put,
679 .property_present = software_node_property_present,
680 .property_read_int_array = software_node_read_int_array,
681 .property_read_string_array = software_node_read_string_array,
682 .get_name = software_node_get_name,
683 .get_name_prefix = software_node_get_name_prefix,
684 .get_parent = software_node_get_parent,
685 .get_next_child_node = software_node_get_next_child,
686 .get_named_child_node = software_node_get_named_child_node,
687 .get_reference_args = software_node_get_reference_args,
688 .graph_get_next_endpoint = software_node_graph_get_next_endpoint,
689 .graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
690 .graph_get_port_parent = software_node_graph_get_port_parent,
691 .graph_parse_endpoint = software_node_graph_parse_endpoint,
692};
693
694/* -------------------------------------------------------------------------- */
695
696/**
697 * software_node_find_by_name - Find software node by name
698 * @parent: Parent of the software node
699 * @name: Name of the software node
700 *
701 * The function will find a node that is child of @parent and that is named
702 * @name. If no node is found, the function returns NULL.
703 *
704 * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
705 */
706const struct software_node *
707software_node_find_by_name(const struct software_node *parent, const char *name)
708{
709 struct swnode *swnode = NULL;
710 struct kobject *k;
711
712 if (!name)
713 return NULL;
714
715 spin_lock(&swnode_kset->list_lock);
716
717 list_for_each_entry(k, &swnode_kset->list, entry) {
718 swnode = kobj_to_swnode(k);
719 if (parent == swnode->node->parent && swnode->node->name &&
720 !strcmp(name, swnode->node->name)) {
721 kobject_get(&swnode->kobj);
722 break;
723 }
724 swnode = NULL;
725 }
726
727 spin_unlock(&swnode_kset->list_lock);
728
729 return swnode ? swnode->node : NULL;
730}
731EXPORT_SYMBOL_GPL(software_node_find_by_name);
732
733static struct software_node *software_node_alloc(const struct property_entry *properties)
734{
735 struct property_entry *props;
736 struct software_node *node;
737
738 props = property_entries_dup(properties);
739 if (IS_ERR(props))
740 return ERR_CAST(props);
741
742 node = kzalloc(sizeof(*node), GFP_KERNEL);
743 if (!node) {
744 property_entries_free(props);
745 return ERR_PTR(-ENOMEM);
746 }
747
748 node->properties = props;
749
750 return node;
751}
752
753static void software_node_free(const struct software_node *node)
754{
755 property_entries_free(node->properties);
756 kfree(node);
757}
758
759static void software_node_release(struct kobject *kobj)
760{
761 struct swnode *swnode = kobj_to_swnode(kobj);
762
763 if (swnode->parent) {
764 ida_free(&swnode->parent->child_ids, swnode->id);
765 list_del(&swnode->entry);
766 } else {
767 ida_free(&swnode_root_ids, swnode->id);
768 }
769
770 if (swnode->allocated)
771 software_node_free(swnode->node);
772
773 ida_destroy(&swnode->child_ids);
774 kfree(swnode);
775}
776
777static const struct kobj_type software_node_type = {
778 .release = software_node_release,
779 .sysfs_ops = &kobj_sysfs_ops,
780};
781
782static struct fwnode_handle *
783swnode_register(const struct software_node *node, struct swnode *parent,
784 unsigned int allocated)
785{
786 struct swnode *swnode;
787 int ret;
788
789 swnode = kzalloc(sizeof(*swnode), GFP_KERNEL);
790 if (!swnode)
791 return ERR_PTR(-ENOMEM);
792
793 ret = ida_alloc(parent ? &parent->child_ids : &swnode_root_ids,
794 GFP_KERNEL);
795 if (ret < 0) {
796 kfree(swnode);
797 return ERR_PTR(ret);
798 }
799
800 swnode->id = ret;
801 swnode->node = node;
802 swnode->parent = parent;
803 swnode->kobj.kset = swnode_kset;
804 fwnode_init(&swnode->fwnode, &software_node_ops);
805
806 ida_init(&swnode->child_ids);
807 INIT_LIST_HEAD(&swnode->entry);
808 INIT_LIST_HEAD(&swnode->children);
809
810 if (node->name)
811 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
812 parent ? &parent->kobj : NULL,
813 "%s", node->name);
814 else
815 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
816 parent ? &parent->kobj : NULL,
817 "node%d", swnode->id);
818 if (ret) {
819 kobject_put(&swnode->kobj);
820 return ERR_PTR(ret);
821 }
822
823 /*
824 * Assign the flag only in the successful case, so
825 * the above kobject_put() won't mess up with properties.
826 */
827 swnode->allocated = allocated;
828
829 if (parent)
830 list_add_tail(&swnode->entry, &parent->children);
831
832 kobject_uevent(&swnode->kobj, KOBJ_ADD);
833 return &swnode->fwnode;
834}
835
836/**
837 * software_node_register_node_group - Register a group of software nodes
838 * @node_group: NULL terminated array of software node pointers to be registered
839 *
840 * Register multiple software nodes at once. If any node in the array
841 * has its .parent pointer set (which can only be to another software_node),
842 * then its parent **must** have been registered before it is; either outside
843 * of this function or by ordering the array such that parent comes before
844 * child.
845 */
846int software_node_register_node_group(const struct software_node **node_group)
847{
848 unsigned int i;
849 int ret;
850
851 if (!node_group)
852 return 0;
853
854 for (i = 0; node_group[i]; i++) {
855 ret = software_node_register(node_group[i]);
856 if (ret) {
857 software_node_unregister_node_group(node_group);
858 return ret;
859 }
860 }
861
862 return 0;
863}
864EXPORT_SYMBOL_GPL(software_node_register_node_group);
865
866/**
867 * software_node_unregister_node_group - Unregister a group of software nodes
868 * @node_group: NULL terminated array of software node pointers to be unregistered
869 *
870 * Unregister multiple software nodes at once. If parent pointers are set up
871 * in any of the software nodes then the array **must** be ordered such that
872 * parents come before their children.
873 *
874 * NOTE: If you are uncertain whether the array is ordered such that
875 * parents will be unregistered before their children, it is wiser to
876 * remove the nodes individually, in the correct order (child before
877 * parent).
878 */
879void software_node_unregister_node_group(
880 const struct software_node **node_group)
881{
882 unsigned int i = 0;
883
884 if (!node_group)
885 return;
886
887 while (node_group[i])
888 i++;
889
890 while (i--)
891 software_node_unregister(node_group[i]);
892}
893EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
894
895/**
896 * software_node_register - Register static software node
897 * @node: The software node to be registered
898 */
899int software_node_register(const struct software_node *node)
900{
901 struct swnode *parent = software_node_to_swnode(node->parent);
902
903 if (software_node_to_swnode(node))
904 return -EEXIST;
905
906 if (node->parent && !parent)
907 return -EINVAL;
908
909 return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
910}
911EXPORT_SYMBOL_GPL(software_node_register);
912
913/**
914 * software_node_unregister - Unregister static software node
915 * @node: The software node to be unregistered
916 */
917void software_node_unregister(const struct software_node *node)
918{
919 struct swnode *swnode;
920
921 swnode = software_node_to_swnode(node);
922 if (swnode)
923 fwnode_remove_software_node(&swnode->fwnode);
924}
925EXPORT_SYMBOL_GPL(software_node_unregister);
926
927struct fwnode_handle *
928fwnode_create_software_node(const struct property_entry *properties,
929 const struct fwnode_handle *parent)
930{
931 struct fwnode_handle *fwnode;
932 struct software_node *node;
933 struct swnode *p;
934
935 if (IS_ERR(parent))
936 return ERR_CAST(parent);
937
938 p = to_swnode(parent);
939 if (parent && !p)
940 return ERR_PTR(-EINVAL);
941
942 node = software_node_alloc(properties);
943 if (IS_ERR(node))
944 return ERR_CAST(node);
945
946 node->parent = p ? p->node : NULL;
947
948 fwnode = swnode_register(node, p, 1);
949 if (IS_ERR(fwnode))
950 software_node_free(node);
951
952 return fwnode;
953}
954EXPORT_SYMBOL_GPL(fwnode_create_software_node);
955
956void fwnode_remove_software_node(struct fwnode_handle *fwnode)
957{
958 struct swnode *swnode = to_swnode(fwnode);
959
960 if (!swnode)
961 return;
962
963 kobject_put(&swnode->kobj);
964}
965EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
966
967/**
968 * device_add_software_node - Assign software node to a device
969 * @dev: The device the software node is meant for.
970 * @node: The software node.
971 *
972 * This function will make @node the secondary firmware node pointer of @dev. If
973 * @dev has no primary node, then @node will become the primary node. The
974 * function will register @node automatically if it wasn't already registered.
975 */
976int device_add_software_node(struct device *dev, const struct software_node *node)
977{
978 struct swnode *swnode;
979 int ret;
980
981 /* Only one software node per device. */
982 if (dev_to_swnode(dev))
983 return -EBUSY;
984
985 swnode = software_node_to_swnode(node);
986 if (swnode) {
987 kobject_get(&swnode->kobj);
988 } else {
989 ret = software_node_register(node);
990 if (ret)
991 return ret;
992
993 swnode = software_node_to_swnode(node);
994 }
995
996 set_secondary_fwnode(dev, &swnode->fwnode);
997
998 /*
999 * If the device has been fully registered by the time this function is
1000 * called, software_node_notify() must be called separately so that the
1001 * symlinks get created and the reference count of the node is kept in
1002 * balance.
1003 */
1004 if (device_is_registered(dev))
1005 software_node_notify(dev);
1006
1007 return 0;
1008}
1009EXPORT_SYMBOL_GPL(device_add_software_node);
1010
1011/**
1012 * device_remove_software_node - Remove device's software node
1013 * @dev: The device with the software node.
1014 *
1015 * This function will unregister the software node of @dev.
1016 */
1017void device_remove_software_node(struct device *dev)
1018{
1019 struct swnode *swnode;
1020
1021 swnode = dev_to_swnode(dev);
1022 if (!swnode)
1023 return;
1024
1025 if (device_is_registered(dev))
1026 software_node_notify_remove(dev);
1027
1028 set_secondary_fwnode(dev, NULL);
1029 kobject_put(&swnode->kobj);
1030}
1031EXPORT_SYMBOL_GPL(device_remove_software_node);
1032
1033/**
1034 * device_create_managed_software_node - Create a software node for a device
1035 * @dev: The device the software node is assigned to.
1036 * @properties: Device properties for the software node.
1037 * @parent: Parent of the software node.
1038 *
1039 * Creates a software node as a managed resource for @dev, which means the
1040 * lifetime of the newly created software node is tied to the lifetime of @dev.
1041 * Software nodes created with this function should not be reused or shared
1042 * because of that. The function takes a deep copy of @properties for the
1043 * software node.
1044 *
1045 * Since the new software node is assigned directly to @dev, and since it should
1046 * not be shared, it is not returned to the caller. The function returns 0 on
1047 * success, and errno in case of an error.
1048 */
1049int device_create_managed_software_node(struct device *dev,
1050 const struct property_entry *properties,
1051 const struct software_node *parent)
1052{
1053 struct fwnode_handle *p = software_node_fwnode(parent);
1054 struct fwnode_handle *fwnode;
1055
1056 if (parent && !p)
1057 return -EINVAL;
1058
1059 fwnode = fwnode_create_software_node(properties, p);
1060 if (IS_ERR(fwnode))
1061 return PTR_ERR(fwnode);
1062
1063 to_swnode(fwnode)->managed = true;
1064 set_secondary_fwnode(dev, fwnode);
1065
1066 if (device_is_registered(dev))
1067 software_node_notify(dev);
1068
1069 return 0;
1070}
1071EXPORT_SYMBOL_GPL(device_create_managed_software_node);
1072
1073void software_node_notify(struct device *dev)
1074{
1075 struct swnode *swnode;
1076 int ret;
1077
1078 swnode = dev_to_swnode(dev);
1079 if (!swnode)
1080 return;
1081
1082 ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
1083 if (ret)
1084 return;
1085
1086 ret = sysfs_create_link(&swnode->kobj, &dev->kobj, dev_name(dev));
1087 if (ret) {
1088 sysfs_remove_link(&dev->kobj, "software_node");
1089 return;
1090 }
1091
1092 kobject_get(&swnode->kobj);
1093}
1094
1095void software_node_notify_remove(struct device *dev)
1096{
1097 struct swnode *swnode;
1098
1099 swnode = dev_to_swnode(dev);
1100 if (!swnode)
1101 return;
1102
1103 sysfs_remove_link(&swnode->kobj, dev_name(dev));
1104 sysfs_remove_link(&dev->kobj, "software_node");
1105 kobject_put(&swnode->kobj);
1106
1107 if (swnode->managed) {
1108 set_secondary_fwnode(dev, NULL);
1109 kobject_put(&swnode->kobj);
1110 }
1111}
1112
1113static int __init software_node_init(void)
1114{
1115 swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj);
1116 if (!swnode_kset)
1117 return -ENOMEM;
1118 return 0;
1119}
1120postcore_initcall(software_node_init);
1121
1122static void __exit software_node_exit(void)
1123{
1124 ida_destroy(&swnode_root_ids);
1125 kset_unregister(swnode_kset);
1126}
1127__exitcall(software_node_exit);