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