drivers/base/swnode.c

   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 struct swnode {
  15         int id;
  16         struct kobject kobj;
  17         struct fwnode_handle fwnode;
  18         const struct software_node *node;
  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 };
  28
  29 static DEFINE_IDA(swnode_root_ids);
  30 static struct kset *swnode_kset;
  31
  32 #define kobj_to_swnode(_kobj_) container_of(_kobj_, struct swnode, kobj)
  33
  34 static const struct fwnode_operations software_node_ops;
  35
  36 bool is_software_node(const struct fwnode_handle *fwnode)
  37 {
  38         return !IS_ERR_OR_NULL(fwnode) && fwnode->ops == &software_node_ops;
  39 }
  40 EXPORT_SYMBOL_GPL(is_software_node);
  41
  42 #define to_swnode(__fwnode)                                             \
  43         ({                                                              \
  44                 typeof(__fwnode) __to_swnode_fwnode = __fwnode;         \
  45                                                                         \
  46                 is_software_node(__to_swnode_fwnode) ?                  \
  47                         container_of(__to_swnode_fwnode,                \
  48                                      struct swnode, fwnode) : NULL;     \
  49         })
  50
  51 static struct swnode *
  52 software_node_to_swnode(const struct software_node *node)
  53 {
  54         struct swnode *swnode = NULL;
  55         struct kobject *k;
  56
  57         if (!node)
  58                 return NULL;
  59
  60         spin_lock(&swnode_kset->list_lock);
  61
  62         list_for_each_entry(k, &swnode_kset->list, entry) {
  63                 swnode = kobj_to_swnode(k);
  64                 if (swnode->node == node)
  65                         break;
  66                 swnode = NULL;
  67         }
  68
  69         spin_unlock(&swnode_kset->list_lock);
  70
  71         return swnode;
  72 }
  73
  74 const struct software_node *to_software_node(struct fwnode_handle *fwnode)
  75 {
  76         struct swnode *swnode = to_swnode(fwnode);
  77
  78         return swnode ? swnode->node : NULL;
  79 }
  80 EXPORT_SYMBOL_GPL(to_software_node);
  81
  82 struct fwnode_handle *software_node_fwnode(const struct software_node *node)
  83 {
  84         struct swnode *swnode = software_node_to_swnode(node);
  85
  86         return swnode ? &swnode->fwnode : NULL;
  87 }
  88 EXPORT_SYMBOL_GPL(software_node_fwnode);
  89
  90 /* -------------------------------------------------------------------------- */
  91 /* property_entry processing */
  92
  93 static const struct property_entry *
  94 property_entry_get(const struct property_entry *prop, const char *name)
  95 {
  96         if (!prop)
  97                 return NULL;
  98
  99         for (; prop->name; prop++)
 100                 if (!strcmp(name, prop->name))
 101                         return prop;
 102
 103         return NULL;
 104 }
 105
 106 static void
 107 property_set_pointer(struct property_entry *prop, const void *pointer)
 108 {
 109         switch (prop->type) {
 110         case DEV_PROP_U8:
 111                 if (prop->is_array)
 112                         prop->pointer.u8_data = pointer;
 113                 else
 114                         prop->value.u8_data = *((u8 *)pointer);
 115                 break;
 116         case DEV_PROP_U16:
 117                 if (prop->is_array)
 118                         prop->pointer.u16_data = pointer;
 119                 else
 120                         prop->value.u16_data = *((u16 *)pointer);
 121                 break;
 122         case DEV_PROP_U32:
 123                 if (prop->is_array)
 124                         prop->pointer.u32_data = pointer;
 125                 else
 126                         prop->value.u32_data = *((u32 *)pointer);
 127                 break;
 128         case DEV_PROP_U64:
 129                 if (prop->is_array)
 130                         prop->pointer.u64_data = pointer;
 131                 else
 132                         prop->value.u64_data = *((u64 *)pointer);
 133                 break;
 134         case DEV_PROP_STRING:
 135                 if (prop->is_array)
 136                         prop->pointer.str = pointer;
 137                 else
 138                         prop->value.str = pointer;
 139                 break;
 140         default:
 141                 break;
 142         }
 143 }
 144
 145 static const void *property_get_pointer(const struct property_entry *prop)
 146 {
 147         switch (prop->type) {
 148         case DEV_PROP_U8:
 149                 if (prop->is_array)
 150                         return prop->pointer.u8_data;
 151                 return &prop->value.u8_data;
 152         case DEV_PROP_U16:
 153                 if (prop->is_array)
 154                         return prop->pointer.u16_data;
 155                 return &prop->value.u16_data;
 156         case DEV_PROP_U32:
 157                 if (prop->is_array)
 158                         return prop->pointer.u32_data;
 159                 return &prop->value.u32_data;
 160         case DEV_PROP_U64:
 161                 if (prop->is_array)
 162                         return prop->pointer.u64_data;
 163                 return &prop->value.u64_data;
 164         case DEV_PROP_STRING:
 165                 if (prop->is_array)
 166                         return prop->pointer.str;
 167                 return &prop->value.str;
 168         default:
 169                 return NULL;
 170         }
 171 }
 172
 173 static const void *property_entry_find(const struct property_entry *props,
 174                                        const char *propname, size_t length)
 175 {
 176         const struct property_entry *prop;
 177         const void *pointer;
 178
 179         prop = property_entry_get(props, propname);
 180         if (!prop)
 181                 return ERR_PTR(-EINVAL);
 182         pointer = property_get_pointer(prop);
 183         if (!pointer)
 184                 return ERR_PTR(-ENODATA);
 185         if (length > prop->length)
 186                 return ERR_PTR(-EOVERFLOW);
 187         return pointer;
 188 }
 189
 190 static int property_entry_read_u8_array(const struct property_entry *props,
 191                                         const char *propname,
 192                                         u8 *values, size_t nval)
 193 {
 194         const void *pointer;
 195         size_t length = nval * sizeof(*values);
 196
 197         pointer = property_entry_find(props, propname, length);
 198         if (IS_ERR(pointer))
 199                 return PTR_ERR(pointer);
 200
 201         memcpy(values, pointer, length);
 202         return 0;
 203 }
 204
 205 static int property_entry_read_u16_array(const struct property_entry *props,
 206                                          const char *propname,
 207                                          u16 *values, size_t nval)
 208 {
 209         const void *pointer;
 210         size_t length = nval * sizeof(*values);
 211
 212         pointer = property_entry_find(props, propname, length);
 213         if (IS_ERR(pointer))
 214                 return PTR_ERR(pointer);
 215
 216         memcpy(values, pointer, length);
 217         return 0;
 218 }
 219
 220 static int property_entry_read_u32_array(const struct property_entry *props,
 221                                          const char *propname,
 222                                          u32 *values, size_t nval)
 223 {
 224         const void *pointer;
 225         size_t length = nval * sizeof(*values);
 226
 227         pointer = property_entry_find(props, propname, length);
 228         if (IS_ERR(pointer))
 229                 return PTR_ERR(pointer);
 230
 231         memcpy(values, pointer, length);
 232         return 0;
 233 }
 234
 235 static int property_entry_read_u64_array(const struct property_entry *props,
 236                                          const char *propname,
 237                                          u64 *values, size_t nval)
 238 {
 239         const void *pointer;
 240         size_t length = nval * sizeof(*values);
 241
 242         pointer = property_entry_find(props, propname, length);
 243         if (IS_ERR(pointer))
 244                 return PTR_ERR(pointer);
 245
 246         memcpy(values, pointer, length);
 247         return 0;
 248 }
 249
 250 static int
 251 property_entry_count_elems_of_size(const struct property_entry *props,
 252                                    const char *propname, size_t length)
 253 {
 254         const struct property_entry *prop;
 255
 256         prop = property_entry_get(props, propname);
 257         if (!prop)
 258                 return -EINVAL;
 259
 260         return prop->length / length;
 261 }
 262
 263 static int property_entry_read_int_array(const struct property_entry *props,
 264                                          const char *name,
 265                                          unsigned int elem_size, void *val,
 266                                          size_t nval)
 267 {
 268         if (!val)
 269                 return property_entry_count_elems_of_size(props, name,
 270                                                           elem_size);
 271         switch (elem_size) {
 272         case sizeof(u8):
 273                 return property_entry_read_u8_array(props, name, val, nval);
 274         case sizeof(u16):
 275                 return property_entry_read_u16_array(props, name, val, nval);
 276         case sizeof(u32):
 277                 return property_entry_read_u32_array(props, name, val, nval);
 278         case sizeof(u64):
 279                 return property_entry_read_u64_array(props, name, val, nval);
 280         }
 281
 282         return -ENXIO;
 283 }
 284
 285 static int property_entry_read_string_array(const struct property_entry *props,
 286                                             const char *propname,
 287                                             const char **strings, size_t nval)
 288 {
 289         const struct property_entry *prop;
 290         const void *pointer;
 291         size_t array_len, length;
 292
 293         /* Find out the array length. */
 294         prop = property_entry_get(props, propname);
 295         if (!prop)
 296                 return -EINVAL;
 297
 298         if (prop->is_array)
 299                 /* Find the length of an array. */
 300                 array_len = property_entry_count_elems_of_size(props, propname,
 301                                                           sizeof(const char *));
 302         else
 303                 /* The array length for a non-array string property is 1. */
 304                 array_len = 1;
 305
 306         /* Return how many there are if strings is NULL. */
 307         if (!strings)
 308                 return array_len;
 309
 310         array_len = min(nval, array_len);
 311         length = array_len * sizeof(*strings);
 312
 313         pointer = property_entry_find(props, propname, length);
 314         if (IS_ERR(pointer))
 315                 return PTR_ERR(pointer);
 316
 317         memcpy(strings, pointer, length);
 318
 319         return array_len;
 320 }
 321
 322 static void property_entry_free_data(const struct property_entry *p)
 323 {
 324         const void *pointer = property_get_pointer(p);
 325         size_t i, nval;
 326
 327         if (p->is_array) {
 328                 if (p->type == DEV_PROP_STRING && p->pointer.str) {
 329                         nval = p->length / sizeof(const char *);
 330                         for (i = 0; i < nval; i++)
 331                                 kfree(p->pointer.str[i]);
 332                 }
 333                 kfree(pointer);
 334         } else if (p->type == DEV_PROP_STRING) {
 335                 kfree(p->value.str);
 336         }
 337         kfree(p->name);
 338 }
 339
 340 static int property_copy_string_array(struct property_entry *dst,
 341                                       const struct property_entry *src)
 342 {
 343         const char **d;
 344         size_t nval = src->length / sizeof(*d);
 345         int i;
 346
 347         d = kcalloc(nval, sizeof(*d), GFP_KERNEL);
 348         if (!d)
 349                 return -ENOMEM;
 350
 351         for (i = 0; i < nval; i++) {
 352                 d[i] = kstrdup(src->pointer.str[i], GFP_KERNEL);
 353                 if (!d[i] && src->pointer.str[i]) {
 354                         while (--i >= 0)
 355                                 kfree(d[i]);
 356                         kfree(d);
 357                         return -ENOMEM;
 358                 }
 359         }
 360
 361         dst->pointer.str = d;
 362         return 0;
 363 }
 364
 365 static int property_entry_copy_data(struct property_entry *dst,
 366                                     const struct property_entry *src)
 367 {
 368         const void *pointer = property_get_pointer(src);
 369         const void *new;
 370         int error;
 371
 372         if (src->is_array) {
 373                 if (!src->length)
 374                         return -ENODATA;
 375
 376                 if (src->type == DEV_PROP_STRING) {
 377                         error = property_copy_string_array(dst, src);
 378                         if (error)
 379                                 return error;
 380                         new = dst->pointer.str;
 381                 } else {
 382                         new = kmemdup(pointer, src->length, GFP_KERNEL);
 383                         if (!new)
 384                                 return -ENOMEM;
 385                 }
 386         } else if (src->type == DEV_PROP_STRING) {
 387                 new = kstrdup(src->value.str, GFP_KERNEL);
 388                 if (!new && src->value.str)
 389                         return -ENOMEM;
 390         } else {
 391                 new = pointer;
 392         }
 393
 394         dst->length = src->length;
 395         dst->is_array = src->is_array;
 396         dst->type = src->type;
 397
 398         property_set_pointer(dst, new);
 399
 400         dst->name = kstrdup(src->name, GFP_KERNEL);
 401         if (!dst->name)
 402                 goto out_free_data;
 403
 404         return 0;
 405
 406 out_free_data:
 407         property_entry_free_data(dst);
 408         return -ENOMEM;
 409 }
 410
 411 /**
 412  * property_entries_dup - duplicate array of properties
 413  * @properties: array of properties to copy
 414  *
 415  * This function creates a deep copy of the given NULL-terminated array
 416  * of property entries.
 417  */
 418 struct property_entry *
 419 property_entries_dup(const struct property_entry *properties)
 420 {
 421         struct property_entry *p;
 422         int i, n = 0;
 423         int ret;
 424
 425         if (!properties)
 426                 return NULL;
 427
 428         while (properties[n].name)
 429                 n++;
 430
 431         p = kcalloc(n + 1, sizeof(*p), GFP_KERNEL);
 432         if (!p)
 433                 return ERR_PTR(-ENOMEM);
 434
 435         for (i = 0; i < n; i++) {
 436                 ret = property_entry_copy_data(&p[i], &properties[i]);
 437                 if (ret) {
 438                         while (--i >= 0)
 439                                 property_entry_free_data(&p[i]);
 440                         kfree(p);
 441                         return ERR_PTR(ret);
 442                 }
 443         }
 444
 445         return p;
 446 }
 447 EXPORT_SYMBOL_GPL(property_entries_dup);
 448
 449 /**
 450  * property_entries_free - free previously allocated array of properties
 451  * @properties: array of properties to destroy
 452  *
 453  * This function frees given NULL-terminated array of property entries,
 454  * along with their data.
 455  */
 456 void property_entries_free(const struct property_entry *properties)
 457 {
 458         const struct property_entry *p;
 459
 460         if (!properties)
 461                 return;
 462
 463         for (p = properties; p->name; p++)
 464                 property_entry_free_data(p);
 465
 466         kfree(properties);
 467 }
 468 EXPORT_SYMBOL_GPL(property_entries_free);
 469
 470 /* -------------------------------------------------------------------------- */
 471 /* fwnode operations */
 472
 473 static struct fwnode_handle *software_node_get(struct fwnode_handle *fwnode)
 474 {
 475         struct swnode *swnode = to_swnode(fwnode);
 476
 477         kobject_get(&swnode->kobj);
 478
 479         return &swnode->fwnode;
 480 }
 481
 482 static void software_node_put(struct fwnode_handle *fwnode)
 483 {
 484         struct swnode *swnode = to_swnode(fwnode);
 485
 486         kobject_put(&swnode->kobj);
 487 }
 488
 489 static bool software_node_property_present(const struct fwnode_handle *fwnode,
 490                                            const char *propname)
 491 {
 492         struct swnode *swnode = to_swnode(fwnode);
 493
 494         return !!property_entry_get(swnode->node->properties, propname);
 495 }
 496
 497 static int software_node_read_int_array(const struct fwnode_handle *fwnode,
 498                                         const char *propname,
 499                                         unsigned int elem_size, void *val,
 500                                         size_t nval)
 501 {
 502         struct swnode *swnode = to_swnode(fwnode);
 503
 504         return property_entry_read_int_array(swnode->node->properties, propname,
 505                                              elem_size, val, nval);
 506 }
 507
 508 static int software_node_read_string_array(const struct fwnode_handle *fwnode,
 509                                            const char *propname,
 510                                            const char **val, size_t nval)
 511 {
 512         struct swnode *swnode = to_swnode(fwnode);
 513
 514         return property_entry_read_string_array(swnode->node->properties,
 515                                                 propname, val, nval);
 516 }
 517
 518 static struct fwnode_handle *
 519 software_node_get_parent(const struct fwnode_handle *fwnode)
 520 {
 521         struct swnode *swnode = to_swnode(fwnode);
 522
 523         return swnode ? (swnode->parent ? &swnode->parent->fwnode : NULL) : NULL;
 524 }
 525
 526 static struct fwnode_handle *
 527 software_node_get_next_child(const struct fwnode_handle *fwnode,
 528                              struct fwnode_handle *child)
 529 {
 530         struct swnode *p = to_swnode(fwnode);
 531         struct swnode *c = to_swnode(child);
 532
 533         if (!p || list_empty(&p->children) ||
 534             (c && list_is_last(&c->entry, &p->children)))
 535                 return NULL;
 536
 537         if (c)
 538                 c = list_next_entry(c, entry);
 539         else
 540                 c = list_first_entry(&p->children, struct swnode, entry);
 541         return &c->fwnode;
 542 }
 543
 544 static struct fwnode_handle *
 545 software_node_get_named_child_node(const struct fwnode_handle *fwnode,
 546                                    const char *childname)
 547 {
 548         struct swnode *swnode = to_swnode(fwnode);
 549         struct swnode *child;
 550
 551         if (!swnode || list_empty(&swnode->children))
 552                 return NULL;
 553
 554         list_for_each_entry(child, &swnode->children, entry) {
 555                 if (!strcmp(childname, kobject_name(&child->kobj))) {
 556                         kobject_get(&child->kobj);
 557                         return &child->fwnode;
 558                 }
 559         }
 560         return NULL;
 561 }
 562
 563 static int
 564 software_node_get_reference_args(const struct fwnode_handle *fwnode,
 565                                  const char *propname, const char *nargs_prop,
 566                                  unsigned int nargs, unsigned int index,
 567                                  struct fwnode_reference_args *args)
 568 {
 569         struct swnode *swnode = to_swnode(fwnode);
 570         const struct software_node_reference *ref;
 571         const struct property_entry *prop;
 572         struct fwnode_handle *refnode;
 573         int i;
 574
 575         if (!swnode || !swnode->node->references)
 576                 return -ENOENT;
 577
 578         for (ref = swnode->node->references; ref->name; ref++)
 579                 if (!strcmp(ref->name, propname))
 580                         break;
 581
 582         if (!ref->name || index > (ref->nrefs - 1))
 583                 return -ENOENT;
 584
 585         refnode = software_node_fwnode(ref->refs[index].node);
 586         if (!refnode)
 587                 return -ENOENT;
 588
 589         if (nargs_prop) {
 590                 prop = property_entry_get(swnode->node->properties, nargs_prop);
 591                 if (!prop)
 592                         return -EINVAL;
 593
 594                 nargs = prop->value.u32_data;
 595         }
 596
 597         if (nargs > NR_FWNODE_REFERENCE_ARGS)
 598                 return -EINVAL;
 599
 600         args->fwnode = software_node_get(refnode);
 601         args->nargs = nargs;
 602
 603         for (i = 0; i < nargs; i++)
 604                 args->args[i] = ref->refs[index].args[i];
 605
 606         return 0;
 607 }
 608
 609 static const struct fwnode_operations software_node_ops = {
 610         .get = software_node_get,
 611         .put = software_node_put,
 612         .property_present = software_node_property_present,
 613         .property_read_int_array = software_node_read_int_array,
 614         .property_read_string_array = software_node_read_string_array,
 615         .get_parent = software_node_get_parent,
 616         .get_next_child_node = software_node_get_next_child,
 617         .get_named_child_node = software_node_get_named_child_node,
 618         .get_reference_args = software_node_get_reference_args
 619 };
 620
 621 /* -------------------------------------------------------------------------- */
 622
 623 /**
 624  * software_node_find_by_name - Find software node by name
 625  * @parent: Parent of the software node
 626  * @name: Name of the software node
 627  *
 628  * The function will find a node that is child of @parent and that is named
 629  * @name. If no node is found, the function returns NULL.
 630  *
 631  * NOTE: you will need to drop the reference with fwnode_handle_put() after use.
 632  */
 633 const struct software_node *
 634 software_node_find_by_name(const struct software_node *parent, const char *name)
 635 {
 636         struct swnode *swnode = NULL;
 637         struct kobject *k;
 638
 639         if (!name)
 640                 return NULL;
 641
 642         spin_lock(&swnode_kset->list_lock);
 643
 644         list_for_each_entry(k, &swnode_kset->list, entry) {
 645                 swnode = kobj_to_swnode(k);
 646                 if (parent == swnode->node->parent && swnode->node->name &&
 647                     !strcmp(name, swnode->node->name)) {
 648                         kobject_get(&swnode->kobj);
 649                         break;
 650                 }
 651                 swnode = NULL;
 652         }
 653
 654         spin_unlock(&swnode_kset->list_lock);
 655
 656         return swnode ? swnode->node : NULL;
 657 }
 658 EXPORT_SYMBOL_GPL(software_node_find_by_name);
 659
 660 static int
 661 software_node_register_properties(struct software_node *node,
 662                                   const struct property_entry *properties)
 663 {
 664         struct property_entry *props;
 665
 666         props = property_entries_dup(properties);
 667         if (IS_ERR(props))
 668                 return PTR_ERR(props);
 669
 670         node->properties = props;
 671
 672         return 0;
 673 }
 674
 675 static void software_node_release(struct kobject *kobj)
 676 {
 677         struct swnode *swnode = kobj_to_swnode(kobj);
 678
 679         if (swnode->allocated) {
 680                 property_entries_free(swnode->node->properties);
 681                 kfree(swnode->node);
 682         }
 683         ida_destroy(&swnode->child_ids);
 684         kfree(swnode);
 685 }
 686
 687 static struct kobj_type software_node_type = {
 688         .release = software_node_release,
 689         .sysfs_ops = &kobj_sysfs_ops,
 690 };
 691
 692 static struct fwnode_handle *
 693 swnode_register(const struct software_node *node, struct swnode *parent,
 694                 unsigned int allocated)
 695 {
 696         struct swnode *swnode;
 697         int ret;
 698
 699         swnode = kzalloc(sizeof(*swnode), GFP_KERNEL);
 700         if (!swnode) {
 701                 ret = -ENOMEM;
 702                 goto out_err;
 703         }
 704
 705         ret = ida_simple_get(parent ? &parent->child_ids : &swnode_root_ids,
 706                              0, 0, GFP_KERNEL);
 707         if (ret < 0) {
 708                 kfree(swnode);
 709                 goto out_err;
 710         }
 711
 712         swnode->id = ret;
 713         swnode->node = node;
 714         swnode->parent = parent;
 715         swnode->allocated = allocated;
 716         swnode->kobj.kset = swnode_kset;
 717         swnode->fwnode.ops = &software_node_ops;
 718
 719         ida_init(&swnode->child_ids);
 720         INIT_LIST_HEAD(&swnode->entry);
 721         INIT_LIST_HEAD(&swnode->children);
 722
 723         if (node->name)
 724                 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
 725                                            parent ? &parent->kobj : NULL,
 726                                            "%s", node->name);
 727         else
 728                 ret = kobject_init_and_add(&swnode->kobj, &software_node_type,
 729                                            parent ? &parent->kobj : NULL,
 730                                            "node%d", swnode->id);
 731         if (ret) {
 732                 kobject_put(&swnode->kobj);
 733                 return ERR_PTR(ret);
 734         }
 735
 736         if (parent)
 737                 list_add_tail(&swnode->entry, &parent->children);
 738
 739         kobject_uevent(&swnode->kobj, KOBJ_ADD);
 740         return &swnode->fwnode;
 741
 742 out_err:
 743         if (allocated)
 744                 property_entries_free(node->properties);
 745         return ERR_PTR(ret);
 746 }
 747
 748 /**
 749  * software_node_register_nodes - Register an array of software nodes
 750  * @nodes: Zero terminated array of software nodes to be registered
 751  *
 752  * Register multiple software nodes at once.
 753  */
 754 int software_node_register_nodes(const struct software_node *nodes)
 755 {
 756         int ret;
 757         int i;
 758
 759         for (i = 0; nodes[i].name; i++) {
 760                 ret = software_node_register(&nodes[i]);
 761                 if (ret) {
 762                         software_node_unregister_nodes(nodes);
 763                         return ret;
 764                 }
 765         }
 766
 767         return 0;
 768 }
 769 EXPORT_SYMBOL_GPL(software_node_register_nodes);
 770
 771 /**
 772  * software_node_unregister_nodes - Unregister an array of software nodes
 773  * @nodes: Zero terminated array of software nodes to be unregistered
 774  *
 775  * Unregister multiple software nodes at once.
 776  */
 777 void software_node_unregister_nodes(const struct software_node *nodes)
 778 {
 779         struct swnode *swnode;
 780         int i;
 781
 782         for (i = 0; nodes[i].name; i++) {
 783                 swnode = software_node_to_swnode(&nodes[i]);
 784                 if (swnode)
 785                         fwnode_remove_software_node(&swnode->fwnode);
 786         }
 787 }
 788 EXPORT_SYMBOL_GPL(software_node_unregister_nodes);
 789
 790 /**
 791  * software_node_register - Register static software node
 792  * @node: The software node to be registered
 793  */
 794 int software_node_register(const struct software_node *node)
 795 {
 796         struct swnode *parent = software_node_to_swnode(node->parent);
 797
 798         if (software_node_to_swnode(node))
 799                 return -EEXIST;
 800
 801         return PTR_ERR_OR_ZERO(swnode_register(node, parent, 0));
 802 }
 803 EXPORT_SYMBOL_GPL(software_node_register);
 804
 805 struct fwnode_handle *
 806 fwnode_create_software_node(const struct property_entry *properties,
 807                             const struct fwnode_handle *parent)
 808 {
 809         struct software_node *node;
 810         struct swnode *p = NULL;
 811         int ret;
 812
 813         if (parent) {
 814                 if (IS_ERR(parent))
 815                         return ERR_CAST(parent);
 816                 if (!is_software_node(parent))
 817                         return ERR_PTR(-EINVAL);
 818                 p = to_swnode(parent);
 819         }
 820
 821         node = kzalloc(sizeof(*node), GFP_KERNEL);
 822         if (!node)
 823                 return ERR_PTR(-ENOMEM);
 824
 825         ret = software_node_register_properties(node, properties);
 826         if (ret) {
 827                 kfree(node);
 828                 return ERR_PTR(ret);
 829         }
 830
 831         node->parent = p ? p->node : NULL;
 832
 833         return swnode_register(node, p, 1);
 834 }
 835 EXPORT_SYMBOL_GPL(fwnode_create_software_node);
 836
 837 void fwnode_remove_software_node(struct fwnode_handle *fwnode)
 838 {
 839         struct swnode *swnode = to_swnode(fwnode);
 840
 841         if (!swnode)
 842                 return;
 843
 844         if (swnode->parent) {
 845                 ida_simple_remove(&swnode->parent->child_ids, swnode->id);
 846                 list_del(&swnode->entry);
 847         } else {
 848                 ida_simple_remove(&swnode_root_ids, swnode->id);
 849         }
 850
 851         kobject_put(&swnode->kobj);
 852 }
 853 EXPORT_SYMBOL_GPL(fwnode_remove_software_node);
 854
 855 int software_node_notify(struct device *dev, unsigned long action)
 856 {
 857         struct fwnode_handle *fwnode = dev_fwnode(dev);
 858         struct swnode *swnode;
 859         int ret;
 860
 861         if (!fwnode)
 862                 return 0;
 863
 864         if (!is_software_node(fwnode))
 865                 fwnode = fwnode->secondary;
 866         if (!is_software_node(fwnode))
 867                 return 0;
 868
 869         swnode = to_swnode(fwnode);
 870
 871         switch (action) {
 872         case KOBJ_ADD:
 873                 ret = sysfs_create_link(&dev->kobj, &swnode->kobj,
 874                                         "software_node");
 875                 if (ret)
 876                         break;
 877
 878                 ret = sysfs_create_link(&swnode->kobj, &dev->kobj,
 879                                         dev_name(dev));
 880                 if (ret) {
 881                         sysfs_remove_link(&dev->kobj, "software_node");
 882                         break;
 883                 }
 884                 kobject_get(&swnode->kobj);
 885                 break;
 886         case KOBJ_REMOVE:
 887                 sysfs_remove_link(&swnode->kobj, dev_name(dev));
 888                 sysfs_remove_link(&dev->kobj, "software_node");
 889                 kobject_put(&swnode->kobj);
 890                 break;
 891         default:
 892                 break;
 893         }
 894
 895         return 0;
 896 }
 897
 898 static int __init software_node_init(void)
 899 {
 900         swnode_kset = kset_create_and_add("software_nodes", NULL, kernel_kobj);
 901         if (!swnode_kset)
 902                 return -ENOMEM;
 903         return 0;
 904 }
 905 postcore_initcall(software_node_init);
 906
 907 static void __exit software_node_exit(void)
 908 {
 909         ida_destroy(&swnode_root_ids);
 910         kset_unregister(swnode_kset);
 911 }
 912 __exitcall(software_node_exit);