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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
14struct swnode {
15 struct kobject kobj;
16 struct fwnode_handle fwnode;
17 const struct software_node *node;
18 int id;
19
20 /* hierarchy */
21 struct ida child_ids;
22 struct list_head entry;
23 struct list_head children;
24 struct swnode *parent;
25
26 unsigned int allocated:1;
27 unsigned int managed:1;
28};
29
30static DEFINE_IDA(swnode_root_ids);
31static struct kset *swnode_kset;
32
33#define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)
34
35static const struct fwnode_operations software_node_ops;
36
37bool is_software_node(const struct fwnode_handle *fwnode)
38{
39 return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
40}
41EXPORT_SYMBOL_GPL(is_software_node);
42
43#define to_swnode(__fwnode) \
44 ({ \
45 typeof(__fwnode) __to_swnode_fwnode = __fwnode; \
46 \
47 is_software_node(__to_swnode_fwnode) ? \
48 container_of(__to_swnode_fwnode, \
49 struct swnode, fwnode) : NULL; \
50 })
51
52static inline struct swnode *dev_to_swnode(struct device *dev)
53{
54 struct fwnode_handle *fwnode = dev_fwnode(dev);
55
56 if (!fwnode)
57 return NULL;
58
59 if (!is_software_node(fwnode))
60 fwnode = fwnode->secondary;
61
62 return to_swnode(fwnode);
63}
64
65static struct swnode *
66software_node_to_swnode(const struct software_node *node)
67{
68 struct swnode *swnode = NULL;
69 struct kobject *k;
70
71 if (!node)
72 return NULL;
73
74 spin_lock(&swnode_kset->list_lock);
75
76 list_for_each_entry(k, &swnode_kset->list, entry) {
77 swnode = kobj_to_swnode(k);
78 if (swnode->node == node)
79 break;
80 swnode = NULL;
81 }
82
83 spin_unlock(&swnode_kset->list_lock);
84
85 return swnode;
86}
87
88const struct software_node *to_software_node(const struct fwnode_handle *fwnode)
89{
90 const struct swnode *swnode = to_swnode(fwnode);
91
92 return swnode ? swnode->node : NULL;
93}
94EXPORT_SYMBOL_GPL(to_software_node);
95
96struct fwnode_handle *software_node_fwnode(const struct software_node *node)
97{
98 struct swnode *swnode = software_node_to_swnode(node);
99
100 return swnode ? &swnode->fwnode : NULL;
101}
102EXPORT_SYMBOL_GPL(software_node_fwnode);
103
104/* -------------------------------------------------------------------------- */
105/* property_entry processing */
106
107static const struct property_entry *
108property_entry_get(const struct property_entry *prop, const char *name)
109{
110 if (!prop)
111 return NULL;
112
113 for (; prop->name; prop++)
114 if (!strcmp(name, prop->name))
115 return prop;
116
117 return NULL;
118}
119
120static const void *property_get_pointer(const struct property_entry *prop)
121{
122 if (!prop->length)
123 return NULL;
124
125 return prop->is_inline ? &prop->value : prop->pointer;
126}
127
128static const void *property_entry_find(const struct property_entry *props,
129 const char *propname, size_t length)
130{
131 const struct property_entry *prop;
132 const void *pointer;
133
134 prop = property_entry_get(props, propname);
135 if (!prop)
136 return ERR_PTR(-EINVAL);
137 pointer = property_get_pointer(prop);
138 if (!pointer)
139 return ERR_PTR(-ENODATA);
140 if (length > prop->length)
141 return ERR_PTR(-EOVERFLOW);
142 return pointer;
143}
144
145static int
146property_entry_count_elems_of_size(const struct property_entry *props,
147 const char *propname, size_t length)
148{
149 const struct property_entry *prop;
150
151 prop = property_entry_get(props, propname);
152 if (!prop)
153 return -EINVAL;
154
155 return prop->length / length;
156}
157
158static int property_entry_read_int_array(const struct property_entry *props,
159 const char *name,
160 unsigned int elem_size, void *val,
161 size_t nval)
162{
163 const void *pointer;
164 size_t length;
165
166 if (!val)
167 return property_entry_count_elems_of_size(props, name,
168 elem_size);
169
170 if (!is_power_of_2(elem_size) || elem_size > sizeof(u64))
171 return -ENXIO;
172
173 length = nval * elem_size;
174
175 pointer = property_entry_find(props, name, length);
176 if (IS_ERR(pointer))
177 return PTR_ERR(pointer);
178
179 memcpy(val, pointer, length);
180 return 0;
181}
182
183static int property_entry_read_string_array(const struct property_entry *props,
184 const char *propname,
185 const char **strings, size_t nval)
186{
187 const void *pointer;
188 size_t length;
189 int array_len;
190
191 /* Find out the array length. */
192 array_len = property_entry_count_elems_of_size(props, propname,
193 sizeof(const char *));
194 if (array_len < 0)
195 return array_len;
196
197 /* Return how many there are if strings is NULL. */
198 if (!strings)
199 return array_len;
200
201 array_len = min_t(size_t, nval, array_len);
202 length = array_len * sizeof(*strings);
203
204 pointer = property_entry_find(props, propname, length);
205 if (IS_ERR(pointer))
206 return PTR_ERR(pointer);
207
208 memcpy(strings, pointer, length);
209
210 return array_len;
211}
212
213static void property_entry_free_data(const struct property_entry *p)
214{
215 const char * const *src_str;
216 size_t i, nval;
217
218 if (p->type == DEV_PROP_STRING) {
219 src_str = property_get_pointer(p);
220 nval = p->length / sizeof(*src_str);
221 for (i = 0; i < nval; i++)
222 kfree(src_str[i]);
223 }
224
225 if (!p->is_inline)
226 kfree(p->pointer);
227
228 kfree(p->name);
229}
230
231static bool property_copy_string_array(const char **dst_ptr,
232 const char * const *src_ptr,
233 size_t nval)
234{
235 int i;
236
237 for (i = 0; i < nval; i++) {
238 dst_ptr[i] = kstrdup(src_ptr[i], GFP_KERNEL);
239 if (!dst_ptr[i] && src_ptr[i]) {
240 while (--i >= 0)
241 kfree(dst_ptr[i]);
242 return false;
243 }
244 }
245
246 return true;
247}
248
249static int property_entry_copy_data(struct property_entry *dst,
250 const struct property_entry *src)
251{
252 const void *pointer = property_get_pointer(src);
253 void *dst_ptr;
254 size_t nval;
255
256 /*
257 * Properties with no data should not be marked as stored
258 * out of line.
259 */
260 if (!src->is_inline && !src->length)
261 return -ENODATA;
262
263 /*
264 * Reference properties are never stored inline as
265 * they are too big.
266 */
267 if (src->type == DEV_PROP_REF && src->is_inline)
268 return -EINVAL;
269
270 if (src->length <= sizeof(dst->value)) {
271 dst_ptr = &dst->value;
272 dst->is_inline = true;
273 } else {
274 dst_ptr = kmalloc(src->length, GFP_KERNEL);
275 if (!dst_ptr)
276 return -ENOMEM;
277 dst->pointer = dst_ptr;
278 }
279
280 if (src->type == DEV_PROP_STRING) {
281 nval = src->length / sizeof(const char *);
282 if (!property_copy_string_array(dst_ptr, pointer, nval)) {
283 if (!dst->is_inline)
284 kfree(dst->pointer);
285 return -ENOMEM;
286 }
287 } else {
288 memcpy(dst_ptr, pointer, src->length);
289 }
290
291 dst->length = src->length;
292 dst->type = src->type;
293 dst->name = kstrdup(src->name, GFP_KERNEL);
294 if (!dst->name) {
295 property_entry_free_data(dst);
296 return -ENOMEM;
297 }
298
299 return 0;
300}
301
302/**
303 * property_entries_dup - duplicate array of properties
304 * @properties: array of properties to copy
305 *
306 * This function creates a deep copy of the given NULL-terminated array
307 * of property entries.
308 */
309struct property_entry *
310property_entries_dup(const struct property_entry *properties)
311{
312 struct property_entry *p;
313 int i, n = 0;
314 int ret;
315
316 if (!properties)
317 return NULL;
318
319 while (properties[n].name)
320 n++;
321
322 p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
323 if (!p)
324 return ERR_PTR(-ENOMEM);
325
326 for (i = 0; i < n; i++) {
327 ret = property_entry_copy_data(&p[i], &properties[i]);
328 if (ret) {
329 while (--i >= 0)
330 property_entry_free_data(&p[i]);
331 kfree(p);
332 return ERR_PTR(ret);
333 }
334 }
335
336 return p;
337}
338EXPORT_SYMBOL_GPL(property_entries_dup);
339
340/**
341 * property_entries_free - free previously allocated array of properties
342 * @properties: array of properties to destroy
343 *
344 * This function frees given NULL-terminated array of property entries,
345 * along with their data.
346 */
347void property_entries_free(const struct property_entry *properties)
348{
349 const struct property_entry *p;
350
351 if (!properties)
352 return;
353
354 for (p = properties; p->name; p++)
355 property_entry_free_data(p);
356
357 kfree(properties);
358}
359EXPORT_SYMBOL_GPL(property_entries_free);
360
361/* -------------------------------------------------------------------------- */
362/* fwnode operations */
363
364static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode)
365{
366 struct swnode *swnode = to_swnode(fwnode);
367
368 kobject_get(&swnode->kobj);
369
370 return &swnode->fwnode;
371}
372
373static void software_node_put(struct fwnode_handle *fwnode)
374{
375 struct swnode *swnode = to_swnode(fwnode);
376
377 kobject_put(&swnode->kobj);
378}
379
380static bool software_node_property_present(const struct fwnode_handle *fwnode,
381 const char *propname)
382{
383 struct swnode *swnode = to_swnode(fwnode);
384
385 return !!property_entry_get(swnode->node->properties, propname);
386}
387
388static int software_node_read_int_array(const struct fwnode_handle *fwnode,
389 const char *propname,
390 unsigned int elem_size, void *val,
391 size_t nval)
392{
393 struct swnode *swnode = to_swnode(fwnode);
394
395 return property_entry_read_int_array(swnode->node->properties, propname,
396 elem_size, val, nval);
397}
398
399static int software_node_read_string_array(const struct fwnode_handle *fwnode,
400 const char *propname,
401 const char **val, size_t nval)
402{
403 struct swnode *swnode = to_swnode(fwnode);
404
405 return property_entry_read_string_array(swnode->node->properties,
406 propname, val, nval);
407}
408
409static const char *
410software_node_get_name(const struct fwnode_handle *fwnode)
411{
412 const struct swnode *swnode = to_swnode(fwnode);
413
414 if (!swnode)
415 return "(null)";
416
417 return kobject_name(&swnode->kobj);
418}
419
420static const char *
421software_node_get_name_prefix(const struct fwnode_handle *fwnode)
422{
423 struct fwnode_handle *parent;
424 const char *prefix;
425
426 parent = fwnode_get_parent(fwnode);
427 if (!parent)
428 return "";
429
430 /* Figure out the prefix from the parents. */
431 while (is_software_node(parent))
432 parent = fwnode_get_next_parent(parent);
433
434 prefix = fwnode_get_name_prefix(parent);
435 fwnode_handle_put(parent);
436
437 /* Guess something if prefix was NULL. */
438 return prefix ?: "/";
439}
440
441static struct fwnode_handle *
442software_node_get_parent(const struct fwnode_handle *fwnode)
443{
444 struct swnode *swnode = to_swnode(fwnode);
445
446 if (!swnode || !swnode->parent)
447 return NULL;
448
449 return fwnode_handle_get(&swnode->parent->fwnode);
450}
451
452static struct fwnode_handle *
453software_node_get_next_child(const struct fwnode_handle *fwnode,
454 struct fwnode_handle *child)
455{
456 struct swnode *p = to_swnode(fwnode);
457 struct swnode *c = to_swnode(child);
458
459 if (!p || list_empty(&p->children) ||
460 (c && list_is_last(&c->entry, &p->children))) {
461 fwnode_handle_put(child);
462 return NULL;
463 }
464
465 if (c)
466 c = list_next_entry(c, entry);
467 else
468 c = list_first_entry(&p->children, struct swnode, entry);
469
470 fwnode_handle_put(child);
471 return fwnode_handle_get(&c->fwnode);
472}
473
474static struct fwnode_handle *
475software_node_get_named_child_node(const struct fwnode_handle *fwnode,
476 const char *childname)
477{
478 struct swnode *swnode = to_swnode(fwnode);
479 struct swnode *child;
480
481 if (!swnode || list_empty(&swnode->children))
482 return NULL;
483
484 list_for_each_entry(child, &swnode->children, entry) {
485 if (!strcmp(childname, kobject_name(&child->kobj))) {
486 kobject_get(&child->kobj);
487 return &child->fwnode;
488 }
489 }
490 return NULL;
491}
492
493static int
494software_node_get_reference_args(const struct fwnode_handle *fwnode,
495 const char *propname, const char *nargs_prop,
496 unsigned int nargs, unsigned int index,
497 struct fwnode_reference_args *args)
498{
499 struct swnode *swnode = to_swnode(fwnode);
500 const struct software_node_ref_args *ref_array;
501 const struct software_node_ref_args *ref;
502 const struct property_entry *prop;
503 struct fwnode_handle *refnode;
504 u32 nargs_prop_val;
505 int error;
506 int i;
507
508 if (!swnode)
509 return -ENOENT;
510
511 prop = property_entry_get(swnode->node->properties, propname);
512 if (!prop)
513 return -ENOENT;
514
515 if (prop->type != DEV_PROP_REF)
516 return -EINVAL;
517
518 /*
519 * We expect that references are never stored inline, even
520 * single ones, as they are too big.
521 */
522 if (prop->is_inline)
523 return -EINVAL;
524
525 if (index * sizeof(*ref) >= prop->length)
526 return -ENOENT;
527
528 ref_array = prop->pointer;
529 ref = &ref_array[index];
530
531 refnode = software_node_fwnode(ref->node);
532 if (!refnode)
533 return -ENOENT;
534
535 if (nargs_prop) {
536 error = property_entry_read_int_array(swnode->node->properties,
537 nargs_prop, sizeof(u32),
538 &nargs_prop_val, 1);
539 if (error)
540 return error;
541
542 nargs = nargs_prop_val;
543 }
544
545 if (nargs > NR_FWNODE_REFERENCE_ARGS)
546 return -EINVAL;
547
548 args->fwnode = software_node_get(refnode);
549 args->nargs = nargs;
550
551 for (i = 0; i < nargs; i++)
552 args->args[i] = ref->args[i];
553
554 return 0;
555}
556
557static struct fwnode_handle *
558swnode_graph_find_next_port(const struct fwnode_handle *parent,
559 struct fwnode_handle *port)
560{
561 struct fwnode_handle *old = port;
562
563 while ((port = software_node_get_next_child(parent, old))) {
564 /*
565 * fwnode ports have naming style "port@", so we search for any
566 * children that follow that convention.
567 */
568 if (!strncmp(to_swnode(port)->node->name, "port@",
569 strlen("port@")))
570 return port;
571 old = port;
572 }
573
574 return NULL;
575}
576
577static struct fwnode_handle *
578software_node_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
579 struct fwnode_handle *endpoint)
580{
581 struct swnode *swnode = to_swnode(fwnode);
582 struct fwnode_handle *parent;
583 struct fwnode_handle *port;
584
585 if (!swnode)
586 return NULL;
587
588 if (endpoint) {
589 port = software_node_get_parent(endpoint);
590 parent = software_node_get_parent(port);
591 } else {
592 parent = software_node_get_named_child_node(fwnode, "ports");
593 if (!parent)
594 parent = software_node_get(&swnode->fwnode);
595
596 port = swnode_graph_find_next_port(parent, NULL);
597 }
598
599 for (; port; port = swnode_graph_find_next_port(parent, port)) {
600 endpoint = software_node_get_next_child(port, endpoint);
601 if (endpoint) {
602 fwnode_handle_put(port);
603 break;
604 }
605 }
606
607 fwnode_handle_put(parent);
608
609 return endpoint;
610}
611
612static struct fwnode_handle *
613software_node_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
614{
615 struct swnode *swnode = to_swnode(fwnode);
616 const struct software_node_ref_args *ref;
617 const struct property_entry *prop;
618
619 if (!swnode)
620 return NULL;
621
622 prop = property_entry_get(swnode->node->properties, "remote-endpoint");
623 if (!prop || prop->type != DEV_PROP_REF || prop->is_inline)
624 return NULL;
625
626 ref = prop->pointer;
627
628 return software_node_get(software_node_fwnode(ref[0].node));
629}
630
631static struct fwnode_handle *
632software_node_graph_get_port_parent(struct fwnode_handle *fwnode)
633{
634 struct swnode *swnode = to_swnode(fwnode);
635
636 swnode = swnode->parent;
637 if (swnode && !strcmp(swnode->node->name, "ports"))
638 swnode = swnode->parent;
639
640 return swnode ? software_node_get(&swnode->fwnode) : NULL;
641}
642
643static int
644software_node_graph_parse_endpoint(const struct fwnode_handle *fwnode,
645 struct fwnode_endpoint *endpoint)
646{
647 struct swnode *swnode = to_swnode(fwnode);
648 const char *parent_name = swnode->parent->node->name;
649 int ret;
650
651 if (strlen("port@") >= strlen(parent_name) ||
652 strncmp(parent_name, "port@", strlen("port@")))
653 return -EINVAL;
654
655 /* Ports have naming style "port@n", we need to select the n */
656 ret = kstrtou32(parent_name + strlen("port@"), 10, &endpoint->port);
657 if (ret)
658 return ret;
659
660 endpoint->id = swnode->id;
661 endpoint->local_fwnode = fwnode;
662
663 return 0;
664}
665
666static const struct fwnode_operations software_node_ops = {
667 .get = software_node_get,
668 .put = software_node_put,
669 .property_present = software_node_property_present,
670 .property_read_int_array = software_node_read_int_array,
671 .property_read_string_array = software_node_read_string_array,
672 .get_name = software_node_get_name,
673 .get_name_prefix = software_node_get_name_prefix,
674 .get_parent = software_node_get_parent,
675 .get_next_child_node = software_node_get_next_child,
676 .get_named_child_node = software_node_get_named_child_node,
677 .get_reference_args = software_node_get_reference_args,
678 .graph_get_next_endpoint = software_node_graph_get_next_endpoint,
679 .graph_get_remote_endpoint = software_node_graph_get_remote_endpoint,
680 .graph_get_port_parent = software_node_graph_get_port_parent,
681 .graph_parse_endpoint = software_node_graph_parse_endpoint,
682};
683
684/* -------------------------------------------------------------------------- */
685
686/**
687 * software_node_find_by_name - Find software node by name
688 * @parent: Parent of the software node
689 * @name: Name of the software node
690 *
691 * The function will find a node that is child of @parent and that is named
692 * @name. If no node is found, the function returns NULL.
693 *
694 * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
695 */
696const struct software_node *
697software_node_find_by_name(const struct software_node *parent, const char *name)
698{
699 struct swnode *swnode = NULL;
700 struct kobject *k;
701
702 if (!name)
703 return NULL;
704
705 spin_lock(&swnode_kset->list_lock);
706
707 list_for_each_entry(k, &swnode_kset->list, entry) {
708 swnode = kobj_to_swnode(k);
709 if (parent == swnode->node->parent && swnode->node->name &&
710 !strcmp(name, swnode->node->name)) {
711 kobject_get(&swnode->kobj);
712 break;
713 }
714 swnode = NULL;
715 }
716
717 spin_unlock(&swnode_kset->list_lock);
718
719 return swnode ? swnode->node : NULL;
720}
721EXPORT_SYMBOL_GPL(software_node_find_by_name);
722
723static struct software_node *software_node_alloc(const struct property_entry *properties)
724{
725 struct property_entry *props;
726 struct software_node *node;
727
728 props = property_entries_dup(properties);
729 if (IS_ERR(props))
730 return ERR_CAST(props);
731
732 node = kzalloc(sizeof(*node), GFP_KERNEL);
733 if (!node) {
734 property_entries_free(props);
735 return ERR_PTR(-ENOMEM);
736 }
737
738 node->properties = props;
739
740 return node;
741}
742
743static void software_node_free(const struct software_node *node)
744{
745 property_entries_free(node->properties);
746 kfree(node);
747}
748
749static void software_node_release(struct kobject *kobj)
750{
751 struct swnode *swnode = kobj_to_swnode(kobj);
752
753 if (swnode->parent) {
754 ida_simple_remove(&swnode->parent->child_ids, swnode->id);
755 list_del(&swnode->entry);
756 } else {
757 ida_simple_remove(&swnode_root_ids, swnode->id);
758 }
759
760 if (swnode->allocated)
761 software_node_free(swnode->node);
762
763 ida_destroy(&swnode->child_ids);
764 kfree(swnode);
765}
766
767static struct kobj_type software_node_type = {
768 .release = software_node_release,
769 .sysfs_ops = &kobj_sysfs_ops,
770};
771
772static struct fwnode_handle *
773swnode_register(const struct software_node *node, struct swnode *parent,
774 unsigned int allocated)
775{
776 struct swnode *swnode;
777 int ret;
778
779 swnode = kzalloc(sizeof(*swnode), GFP_KERNEL);
780 if (!swnode)
781 return ERR_PTR(-ENOMEM);
782
783 ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids,
784 0, 0, GFP_KERNEL);
785 if (ret < 0) {
786 kfree(swnode);
787 return ERR_PTR(ret);
788 }
789
790 swnode->id = ret;
791 swnode->node = node;
792 swnode->parent = parent;
793 swnode->kobj.kset = swnode_kset;
794 fwnode_init(&swnode->fwnode, &software_node_ops);
795
796 ida_init(&swnode->child_ids);
797 INIT_LIST_HEAD(&swnode->entry);
798 INIT_LIST_HEAD(&swnode->children);
799
800 if (node->name)
801 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
802 parent ? &parent->kobj : NULL,
803 "%s", node->name);
804 else
805 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
806 parent ? &parent->kobj : NULL,
807 "node%d", swnode->id);
808 if (ret) {
809 kobject_put(&swnode->kobj);
810 return ERR_PTR(ret);
811 }
812
813 /*
814 * Assign the flag only in the successful case, so
815 * the above kobject_put() won't mess up with properties.
816 */
817 swnode->allocated = allocated;
818
819 if (parent)
820 list_add_tail(&swnode->entry, &parent->children);
821
822 kobject_uevent(&swnode->kobj, KOBJ_ADD);
823 return &swnode->fwnode;
824}
825
826/**
827 * software_node_register_nodes - Register an array of software nodes
828 * @nodes: Zero terminated array of software nodes to be registered
829 *
830 * Register multiple software nodes at once. If any node in the array
831 * has its .parent pointer set (which can only be to another software_node),
832 * then its parent **must** have been registered before it is; either outside
833 * of this function or by ordering the array such that parent comes before
834 * child.
835 */
836int software_node_register_nodes(const struct software_node *nodes)
837{
838 int ret;
839 int i;
840
841 for (i = 0; nodes[i].name; i++) {
842 const struct software_node *parent = nodes[i].parent;
843
844 if (parent && !software_node_to_swnode(parent)) {
845 ret = -EINVAL;
846 goto err_unregister_nodes;
847 }
848
849 ret = software_node_register(&nodes[i]);
850 if (ret)
851 goto err_unregister_nodes;
852 }
853
854 return 0;
855
856err_unregister_nodes:
857 software_node_unregister_nodes(nodes);
858 return ret;
859}
860EXPORT_SYMBOL_GPL(software_node_register_nodes);
861
862/**
863 * software_node_unregister_nodes - Unregister an array of software nodes
864 * @nodes: Zero terminated array of software nodes to be unregistered
865 *
866 * Unregister multiple software nodes at once. If parent pointers are set up
867 * in any of the software nodes then the array **must** be ordered such that
868 * parents come before their children.
869 *
870 * NOTE: If you are uncertain whether the array is ordered such that
871 * parents will be unregistered before their children, it is wiser to
872 * remove the nodes individually, in the correct order (child before
873 * parent).
874 */
875void software_node_unregister_nodes(const struct software_node *nodes)
876{
877 unsigned int i = 0;
878
879 while (nodes[i].name)
880 i++;
881
882 while (i--)
883 software_node_unregister(&nodes[i]);
884}
885EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
886
887/**
888 * software_node_register_node_group - Register a group of software nodes
889 * @node_group: NULL terminated array of software node pointers to be registered
890 *
891 * Register multiple software nodes at once. If any node in the array
892 * has its .parent pointer set (which can only be to another software_node),
893 * then its parent **must** have been registered before it is; either outside
894 * of this function or by ordering the array such that parent comes before
895 * child.
896 */
897int software_node_register_node_group(const struct software_node **node_group)
898{
899 unsigned int i;
900 int ret;
901
902 if (!node_group)
903 return 0;
904
905 for (i = 0; node_group[i]; i++) {
906 ret = software_node_register(node_group[i]);
907 if (ret) {
908 software_node_unregister_node_group(node_group);
909 return ret;
910 }
911 }
912
913 return 0;
914}
915EXPORT_SYMBOL_GPL(software_node_register_node_group);
916
917/**
918 * software_node_unregister_node_group - Unregister a group of software nodes
919 * @node_group: NULL terminated array of software node pointers to be unregistered
920 *
921 * Unregister multiple software nodes at once. If parent pointers are set up
922 * in any of the software nodes then the array **must** be ordered such that
923 * parents come before their children.
924 *
925 * NOTE: If you are uncertain whether the array is ordered such that
926 * parents will be unregistered before their children, it is wiser to
927 * remove the nodes individually, in the correct order (child before
928 * parent).
929 */
930void software_node_unregister_node_group(
931 const struct software_node **node_group)
932{
933 unsigned int i = 0;
934
935 if (!node_group)
936 return;
937
938 while (node_group[i])
939 i++;
940
941 while (i--)
942 software_node_unregister(node_group[i]);
943}
944EXPORT_SYMBOL_GPL(software_node_unregister_node_group);
945
946/**
947 * software_node_register - Register static software node
948 * @node: The software node to be registered
949 */
950int software_node_register(const struct software_node *node)
951{
952 struct swnode *parent = software_node_to_swnode(node->parent);
953
954 if (software_node_to_swnode(node))
955 return -EEXIST;
956
957 if (node->parent && !parent)
958 return -EINVAL;
959
960 return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
961}
962EXPORT_SYMBOL_GPL(software_node_register);
963
964/**
965 * software_node_unregister - Unregister static software node
966 * @node: The software node to be unregistered
967 */
968void software_node_unregister(const struct software_node *node)
969{
970 struct swnode *swnode;
971
972 swnode = software_node_to_swnode(node);
973 if (swnode)
974 fwnode_remove_software_node(&swnode->fwnode);
975}
976EXPORT_SYMBOL_GPL(software_node_unregister);
977
978struct fwnode_handle *
979fwnode_create_software_node(const struct property_entry *properties,
980 const struct fwnode_handle *parent)
981{
982 struct fwnode_handle *fwnode;
983 struct software_node *node;
984 struct swnode *p;
985
986 if (IS_ERR(parent))
987 return ERR_CAST(parent);
988
989 p = to_swnode(parent);
990 if (parent && !p)
991 return ERR_PTR(-EINVAL);
992
993 node = software_node_alloc(properties);
994 if (IS_ERR(node))
995 return ERR_CAST(node);
996
997 node->parent = p ? p->node : NULL;
998
999 fwnode = swnode_register(node, p, 1);
1000 if (IS_ERR(fwnode))
1001 software_node_free(node);
1002
1003 return fwnode;
1004}
1005EXPORT_SYMBOL_GPL(fwnode_create_software_node);
1006
1007void fwnode_remove_software_node(struct fwnode_handle *fwnode)
1008{
1009 struct swnode *swnode = to_swnode(fwnode);
1010
1011 if (!swnode)
1012 return;
1013
1014 kobject_put(&swnode->kobj);
1015}
1016EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
1017
1018/**
1019 * device_add_software_node - Assign software node to a device
1020 * @dev: The device the software node is meant for.
1021 * @node: The software node.
1022 *
1023 * This function will make @node the secondary firmware node pointer of @dev. If
1024 * @dev has no primary node, then @node will become the primary node. The
1025 * function will register @node automatically if it wasn't already registered.
1026 */
1027int device_add_software_node(struct device *dev, const struct software_node *node)
1028{
1029 struct swnode *swnode;
1030 int ret;
1031
1032 /* Only one software node per device. */
1033 if (dev_to_swnode(dev))
1034 return -EBUSY;
1035
1036 swnode = software_node_to_swnode(node);
1037 if (swnode) {
1038 kobject_get(&swnode->kobj);
1039 } else {
1040 ret = software_node_register(node);
1041 if (ret)
1042 return ret;
1043
1044 swnode = software_node_to_swnode(node);
1045 }
1046
1047 set_secondary_fwnode(dev, &swnode->fwnode);
1048
1049 /*
1050 * If the device has been fully registered by the time this function is
1051 * called, software_node_notify() must be called separately so that the
1052 * symlinks get created and the reference count of the node is kept in
1053 * balance.
1054 */
1055 if (device_is_registered(dev))
1056 software_node_notify(dev, KOBJ_ADD);
1057
1058 return 0;
1059}
1060EXPORT_SYMBOL_GPL(device_add_software_node);
1061
1062/**
1063 * device_remove_software_node - Remove device's software node
1064 * @dev: The device with the software node.
1065 *
1066 * This function will unregister the software node of @dev.
1067 */
1068void device_remove_software_node(struct device *dev)
1069{
1070 struct swnode *swnode;
1071
1072 swnode = dev_to_swnode(dev);
1073 if (!swnode)
1074 return;
1075
1076 if (device_is_registered(dev))
1077 software_node_notify(dev, KOBJ_REMOVE);
1078 set_secondary_fwnode(dev, NULL);
1079 kobject_put(&swnode->kobj);
1080}
1081EXPORT_SYMBOL_GPL(device_remove_software_node);
1082
1083/**
1084 * device_create_managed_software_node - Create a software node for a device
1085 * @dev: The device the software node is assigned to.
1086 * @properties: Device properties for the software node.
1087 * @parent: Parent of the software node.
1088 *
1089 * Creates a software node as a managed resource for @dev, which means the
1090 * lifetime of the newly created software node is tied to the lifetime of @dev.
1091 * Software nodes created with this function should not be reused or shared
1092 * because of that. The function takes a deep copy of @properties for the
1093 * software node.
1094 *
1095 * Since the new software node is assigned directly to @dev, and since it should
1096 * not be shared, it is not returned to the caller. The function returns 0 on
1097 * success, and errno in case of an error.
1098 */
1099int device_create_managed_software_node(struct device *dev,
1100 const struct property_entry *properties,
1101 const struct software_node *parent)
1102{
1103 struct fwnode_handle *p = software_node_fwnode(parent);
1104 struct fwnode_handle *fwnode;
1105
1106 if (parent && !p)
1107 return -EINVAL;
1108
1109 fwnode = fwnode_create_software_node(properties, p);
1110 if (IS_ERR(fwnode))
1111 return PTR_ERR(fwnode);
1112
1113 to_swnode(fwnode)->managed = true;
1114 set_secondary_fwnode(dev, fwnode);
1115
1116 if (device_is_registered(dev))
1117 software_node_notify(dev, KOBJ_ADD);
1118
1119 return 0;
1120}
1121EXPORT_SYMBOL_GPL(device_create_managed_software_node);
1122
1123int software_node_notify(struct device *dev, unsigned long action)
1124{
1125 struct swnode *swnode;
1126 int ret;
1127
1128 swnode = dev_to_swnode(dev);
1129 if (!swnode)
1130 return 0;
1131
1132 switch (action) {
1133 case KOBJ_ADD:
1134 ret = sysfs_create_link(&dev->kobj, &swnode->kobj, "software_node");
1135 if (ret)
1136 break;
1137
1138 ret = sysfs_create_link(&swnode->kobj, &dev->kobj,
1139 dev_name(dev));
1140 if (ret) {
1141 sysfs_remove_link(&dev->kobj, "software_node");
1142 break;
1143 }
1144 kobject_get(&swnode->kobj);
1145 break;
1146 case KOBJ_REMOVE:
1147 sysfs_remove_link(&swnode->kobj, dev_name(dev));
1148 sysfs_remove_link(&dev->kobj, "software_node");
1149 kobject_put(&swnode->kobj);
1150
1151 if (swnode->managed) {
1152 set_secondary_fwnode(dev, NULL);
1153 kobject_put(&swnode->kobj);
1154 }
1155 break;
1156 default:
1157 break;
1158 }
1159
1160 return 0;
1161}
1162
1163static int __init software_node_init(void)
1164{
1165 swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj);
1166 if (!swnode_kset)
1167 return -ENOMEM;
1168 return 0;
1169}
1170postcore_initcall(software_node_init);
1171
1172static void __exit software_node_exit(void)
1173{
1174 ida_destroy(&swnode_root_ids);
1175 kset_unregister(swnode_kset);
1176}
1177__exitcall(software_node_exit);
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);