1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corp.
4 * <benh@kernel.crashing.org>
5 * and Arnd Bergmann, IBM Corp.
6 * Merged from powerpc/kernel/of_platform.c and
7 * sparc{,64}/kernel/of_device.c by Stephen Rothwell
8 */
9
10#define pr_fmt(fmt) "OF: " fmt
11
12#include <linux/errno.h>
13#include <linux/module.h>
14#include <linux/amba/bus.h>
15#include <linux/device.h>
16#include <linux/dma-mapping.h>
17#include <linux/slab.h>
18#include <linux/of_address.h>
19#include <linux/of_device.h>
20#include <linux/of_irq.h>
21#include <linux/of_platform.h>
22#include <linux/platform_device.h>
23#include <linux/sysfb.h>
24
25#include "of_private.h"
26
27const struct of_device_id of_default_bus_match_table[] = {
28 { .compatible = "simple-bus", },
29 { .compatible = "simple-mfd", },
30 { .compatible = "isa", },
31#ifdef CONFIG_ARM_AMBA
32 { .compatible = "arm,amba-bus", },
33#endif /* CONFIG_ARM_AMBA */
34 {} /* Empty terminated list */
35};
36
37/**
38 * of_find_device_by_node - Find the platform_device associated with a node
39 * @np: Pointer to device tree node
40 *
41 * Takes a reference to the embedded struct device which needs to be dropped
42 * after use.
43 *
44 * Return: platform_device pointer, or NULL if not found
45 */
46struct platform_device *of_find_device_by_node(struct device_node *np)
47{
48 struct device *dev;
49
50 dev = bus_find_device_by_of_node(bus: &platform_bus_type, np);
51 return dev ? to_platform_device(dev) : NULL;
52}
53EXPORT_SYMBOL(of_find_device_by_node);
54
55int of_device_add(struct platform_device *ofdev)
56{
57 BUG_ON(ofdev->dev.of_node == NULL);
58
59 /* name and id have to be set so that the platform bus doesn't get
60 * confused on matching */
61 ofdev->name = dev_name(dev: &ofdev->dev);
62 ofdev->id = PLATFORM_DEVID_NONE;
63
64 /*
65 * If this device has not binding numa node in devicetree, that is
66 * of_node_to_nid returns NUMA_NO_NODE. device_add will assume that this
67 * device is on the same node as the parent.
68 */
69 set_dev_node(dev: &ofdev->dev, node: of_node_to_nid(np: ofdev->dev.of_node));
70
71 return device_add(dev: &ofdev->dev);
72}
73
74int of_device_register(struct platform_device *pdev)
75{
76 device_initialize(dev: &pdev->dev);
77 return of_device_add(ofdev: pdev);
78}
79EXPORT_SYMBOL(of_device_register);
80
81void of_device_unregister(struct platform_device *ofdev)
82{
83 device_unregister(dev: &ofdev->dev);
84}
85EXPORT_SYMBOL(of_device_unregister);
86
87#ifdef CONFIG_OF_ADDRESS
88static const struct of_device_id of_skipped_node_table[] = {
89 { .compatible = "operating-points-v2", },
90 {} /* Empty terminated list */
91};
92
93/*
94 * The following routines scan a subtree and registers a device for
95 * each applicable node.
96 *
97 * Note: sparc doesn't use these routines because it has a different
98 * mechanism for creating devices from device tree nodes.
99 */
100
101/**
102 * of_device_alloc - Allocate and initialize an of_device
103 * @np: device node to assign to device
104 * @bus_id: Name to assign to the device. May be null to use default name.
105 * @parent: Parent device.
106 */
107struct platform_device *of_device_alloc(struct device_node *np,
108 const char *bus_id,
109 struct device *parent)
110{
111 struct platform_device *dev;
112 int rc, i, num_reg = 0;
113 struct resource *res;
114
115 dev = platform_device_alloc(name: "", PLATFORM_DEVID_NONE);
116 if (!dev)
117 return NULL;
118
119 /* count the io resources */
120 num_reg = of_address_count(np);
121
122 /* Populate the resource table */
123 if (num_reg) {
124 res = kcalloc(n: num_reg, size: sizeof(*res), GFP_KERNEL);
125 if (!res) {
126 platform_device_put(pdev: dev);
127 return NULL;
128 }
129
130 dev->num_resources = num_reg;
131 dev->resource = res;
132 for (i = 0; i < num_reg; i++, res++) {
133 rc = of_address_to_resource(dev: np, index: i, r: res);
134 WARN_ON(rc);
135 }
136 }
137
138 /* setup generic device info */
139 device_set_node(dev: &dev->dev, of_fwnode_handle(of_node_get(np)));
140 dev->dev.parent = parent ? : &platform_bus;
141
142 if (bus_id)
143 dev_set_name(dev: &dev->dev, name: "%s", bus_id);
144 else
145 of_device_make_bus_id(dev: &dev->dev);
146
147 return dev;
148}
149EXPORT_SYMBOL(of_device_alloc);
150
151/**
152 * of_platform_device_create_pdata - Alloc, initialize and register an of_device
153 * @np: pointer to node to create device for
154 * @bus_id: name to assign device
155 * @platform_data: pointer to populate platform_data pointer with
156 * @parent: Linux device model parent device.
157 *
158 * Return: Pointer to created platform device, or NULL if a device was not
159 * registered. Unavailable devices will not get registered.
160 */
161static struct platform_device *of_platform_device_create_pdata(
162 struct device_node *np,
163 const char *bus_id,
164 void *platform_data,
165 struct device *parent)
166{
167 struct platform_device *dev;
168
169 pr_debug("create platform device: %pOF\n", np);
170
171 if (!of_device_is_available(device: np) ||
172 of_node_test_and_set_flag(n: np, OF_POPULATED))
173 return NULL;
174
175 dev = of_device_alloc(np, bus_id, parent);
176 if (!dev)
177 goto err_clear_flag;
178
179 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
180 if (!dev->dev.dma_mask)
181 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
182 dev->dev.bus = &platform_bus_type;
183 dev->dev.platform_data = platform_data;
184 of_msi_configure(dev: &dev->dev, np: dev->dev.of_node);
185
186 if (of_device_add(ofdev: dev) != 0) {
187 platform_device_put(pdev: dev);
188 goto err_clear_flag;
189 }
190
191 return dev;
192
193err_clear_flag:
194 of_node_clear_flag(n: np, OF_POPULATED);
195 return NULL;
196}
197
198/**
199 * of_platform_device_create - Alloc, initialize and register an of_device
200 * @np: pointer to node to create device for
201 * @bus_id: name to assign device
202 * @parent: Linux device model parent device.
203 *
204 * Return: Pointer to created platform device, or NULL if a device was not
205 * registered. Unavailable devices will not get registered.
206 */
207struct platform_device *of_platform_device_create(struct device_node *np,
208 const char *bus_id,
209 struct device *parent)
210{
211 return of_platform_device_create_pdata(np, bus_id, NULL, parent);
212}
213EXPORT_SYMBOL(of_platform_device_create);
214
215#ifdef CONFIG_ARM_AMBA
216static struct amba_device *of_amba_device_create(struct device_node *node,
217 const char *bus_id,
218 void *platform_data,
219 struct device *parent)
220{
221 struct amba_device *dev;
222 int ret;
223
224 pr_debug("Creating amba device %pOF\n", node);
225
226 if (!of_device_is_available(node) ||
227 of_node_test_and_set_flag(node, OF_POPULATED))
228 return NULL;
229
230 dev = amba_device_alloc(NULL, 0, 0);
231 if (!dev)
232 goto err_clear_flag;
233
234 /* AMBA devices only support a single DMA mask */
235 dev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
236 dev->dev.dma_mask = &dev->dev.coherent_dma_mask;
237
238 /* setup generic device info */
239 device_set_node(&dev->dev, of_fwnode_handle(node));
240 dev->dev.parent = parent ? : &platform_bus;
241 dev->dev.platform_data = platform_data;
242 if (bus_id)
243 dev_set_name(&dev->dev, "%s", bus_id);
244 else
245 of_device_make_bus_id(&dev->dev);
246
247 /* Allow the HW Peripheral ID to be overridden */
248 of_property_read_u32(node, "arm,primecell-periphid", &dev->periphid);
249
250 ret = of_address_to_resource(node, 0, &dev->res);
251 if (ret) {
252 pr_err("amba: of_address_to_resource() failed (%d) for %pOF\n",
253 ret, node);
254 goto err_free;
255 }
256
257 ret = amba_device_add(dev, &iomem_resource);
258 if (ret) {
259 pr_err("amba_device_add() failed (%d) for %pOF\n",
260 ret, node);
261 goto err_free;
262 }
263
264 return dev;
265
266err_free:
267 amba_device_put(dev);
268err_clear_flag:
269 of_node_clear_flag(node, OF_POPULATED);
270 return NULL;
271}
272#else /* CONFIG_ARM_AMBA */
273static struct amba_device *of_amba_device_create(struct device_node *node,
274 const char *bus_id,
275 void *platform_data,
276 struct device *parent)
277{
278 return NULL;
279}
280#endif /* CONFIG_ARM_AMBA */
281
282/*
283 * of_dev_lookup() - Given a device node, lookup the preferred Linux name
284 */
285static const struct of_dev_auxdata *of_dev_lookup(const struct of_dev_auxdata *lookup,
286 struct device_node *np)
287{
288 const struct of_dev_auxdata *auxdata;
289 struct resource res;
290 int compatible = 0;
291
292 if (!lookup)
293 return NULL;
294
295 auxdata = lookup;
296 for (; auxdata->compatible; auxdata++) {
297 if (!of_device_is_compatible(device: np, auxdata->compatible))
298 continue;
299 compatible++;
300 if (!of_address_to_resource(dev: np, index: 0, r: &res))
301 if (res.start != auxdata->phys_addr)
302 continue;
303 pr_debug("%pOF: devname=%s\n", np, auxdata->name);
304 return auxdata;
305 }
306
307 if (!compatible)
308 return NULL;
309
310 /* Try compatible match if no phys_addr and name are specified */
311 auxdata = lookup;
312 for (; auxdata->compatible; auxdata++) {
313 if (!of_device_is_compatible(device: np, auxdata->compatible))
314 continue;
315 if (!auxdata->phys_addr && !auxdata->name) {
316 pr_debug("%pOF: compatible match\n", np);
317 return auxdata;
318 }
319 }
320
321 return NULL;
322}
323
324/**
325 * of_platform_bus_create() - Create a device for a node and its children.
326 * @bus: device node of the bus to instantiate
327 * @matches: match table for bus nodes
328 * @lookup: auxdata table for matching id and platform_data with device nodes
329 * @parent: parent for new device, or NULL for top level.
330 * @strict: require compatible property
331 *
332 * Creates a platform_device for the provided device_node, and optionally
333 * recursively create devices for all the child nodes.
334 */
335static int of_platform_bus_create(struct device_node *bus,
336 const struct of_device_id *matches,
337 const struct of_dev_auxdata *lookup,
338 struct device *parent, bool strict)
339{
340 const struct of_dev_auxdata *auxdata;
341 struct device_node *child;
342 struct platform_device *dev;
343 const char *bus_id = NULL;
344 void *platform_data = NULL;
345 int rc = 0;
346
347 /* Make sure it has a compatible property */
348 if (strict && (!of_get_property(node: bus, name: "compatible", NULL))) {
349 pr_debug("%s() - skipping %pOF, no compatible prop\n",
350 __func__, bus);
351 return 0;
352 }
353
354 /* Skip nodes for which we don't want to create devices */
355 if (unlikely(of_match_node(of_skipped_node_table, bus))) {
356 pr_debug("%s() - skipping %pOF node\n", __func__, bus);
357 return 0;
358 }
359
360 if (of_node_check_flag(n: bus, OF_POPULATED_BUS)) {
361 pr_debug("%s() - skipping %pOF, already populated\n",
362 __func__, bus);
363 return 0;
364 }
365
366 auxdata = of_dev_lookup(lookup, np: bus);
367 if (auxdata) {
368 bus_id = auxdata->name;
369 platform_data = auxdata->platform_data;
370 }
371
372 if (of_device_is_compatible(device: bus, "arm,primecell")) {
373 /*
374 * Don't return an error here to keep compatibility with older
375 * device tree files.
376 */
377 of_amba_device_create(node: bus, bus_id, platform_data, parent);
378 return 0;
379 }
380
381 dev = of_platform_device_create_pdata(np: bus, bus_id, platform_data, parent);
382 if (!dev || !of_match_node(matches, node: bus))
383 return 0;
384
385 for_each_child_of_node(bus, child) {
386 pr_debug(" create child: %pOF\n", child);
387 rc = of_platform_bus_create(bus: child, matches, lookup, parent: &dev->dev, strict);
388 if (rc) {
389 of_node_put(node: child);
390 break;
391 }
392 }
393 of_node_set_flag(n: bus, OF_POPULATED_BUS);
394 return rc;
395}
396
397/**
398 * of_platform_bus_probe() - Probe the device-tree for platform buses
399 * @root: parent of the first level to probe or NULL for the root of the tree
400 * @matches: match table for bus nodes
401 * @parent: parent to hook devices from, NULL for toplevel
402 *
403 * Note that children of the provided root are not instantiated as devices
404 * unless the specified root itself matches the bus list and is not NULL.
405 */
406int of_platform_bus_probe(struct device_node *root,
407 const struct of_device_id *matches,
408 struct device *parent)
409{
410 struct device_node *child;
411 int rc = 0;
412
413 root = root ? of_node_get(node: root) : of_find_node_by_path(path: "/");
414 if (!root)
415 return -EINVAL;
416
417 pr_debug("%s()\n", __func__);
418 pr_debug(" starting at: %pOF\n", root);
419
420 /* Do a self check of bus type, if there's a match, create children */
421 if (of_match_node(matches, node: root)) {
422 rc = of_platform_bus_create(bus: root, matches, NULL, parent, strict: false);
423 } else for_each_child_of_node(root, child) {
424 if (!of_match_node(matches, node: child))
425 continue;
426 rc = of_platform_bus_create(bus: child, matches, NULL, parent, strict: false);
427 if (rc) {
428 of_node_put(node: child);
429 break;
430 }
431 }
432
433 of_node_put(node: root);
434 return rc;
435}
436EXPORT_SYMBOL(of_platform_bus_probe);
437
438/**
439 * of_platform_populate() - Populate platform_devices from device tree data
440 * @root: parent of the first level to probe or NULL for the root of the tree
441 * @matches: match table, NULL to use the default
442 * @lookup: auxdata table for matching id and platform_data with device nodes
443 * @parent: parent to hook devices from, NULL for toplevel
444 *
445 * Similar to of_platform_bus_probe(), this function walks the device tree
446 * and creates devices from nodes. It differs in that it follows the modern
447 * convention of requiring all device nodes to have a 'compatible' property,
448 * and it is suitable for creating devices which are children of the root
449 * node (of_platform_bus_probe will only create children of the root which
450 * are selected by the @matches argument).
451 *
452 * New board support should be using this function instead of
453 * of_platform_bus_probe().
454 *
455 * Return: 0 on success, < 0 on failure.
456 */
457int of_platform_populate(struct device_node *root,
458 const struct of_device_id *matches,
459 const struct of_dev_auxdata *lookup,
460 struct device *parent)
461{
462 struct device_node *child;
463 int rc = 0;
464
465 root = root ? of_node_get(node: root) : of_find_node_by_path(path: "/");
466 if (!root)
467 return -EINVAL;
468
469 pr_debug("%s()\n", __func__);
470 pr_debug(" starting at: %pOF\n", root);
471
472 device_links_supplier_sync_state_pause();
473 for_each_child_of_node(root, child) {
474 rc = of_platform_bus_create(bus: child, matches, lookup, parent, strict: true);
475 if (rc) {
476 of_node_put(node: child);
477 break;
478 }
479 }
480 device_links_supplier_sync_state_resume();
481
482 of_node_set_flag(n: root, OF_POPULATED_BUS);
483
484 of_node_put(node: root);
485 return rc;
486}
487EXPORT_SYMBOL_GPL(of_platform_populate);
488
489int of_platform_default_populate(struct device_node *root,
490 const struct of_dev_auxdata *lookup,
491 struct device *parent)
492{
493 return of_platform_populate(root, of_default_bus_match_table, lookup,
494 parent);
495}
496EXPORT_SYMBOL_GPL(of_platform_default_populate);
497
498static const struct of_device_id reserved_mem_matches[] = {
499 { .compatible = "phram" },
500 { .compatible = "qcom,rmtfs-mem" },
501 { .compatible = "qcom,cmd-db" },
502 { .compatible = "qcom,smem" },
503 { .compatible = "ramoops" },
504 { .compatible = "nvmem-rmem" },
505 { .compatible = "google,open-dice" },
506 {}
507};
508
509static int __init of_platform_default_populate_init(void)
510{
511 struct device_node *node;
512
513 device_links_supplier_sync_state_pause();
514
515 if (IS_ENABLED(CONFIG_PPC)) {
516 struct device_node *boot_display = NULL;
517 struct platform_device *dev;
518 int display_number = 0;
519 int ret;
520
521 /* Check if we have a MacOS display without a node spec */
522 if (of_property_present(np: of_chosen, propname: "linux,bootx-noscreen")) {
523 /*
524 * The old code tried to work out which node was the MacOS
525 * display based on the address. I'm dropping that since the
526 * lack of a node spec only happens with old BootX versions
527 * (users can update) and with this code, they'll still get
528 * a display (just not the palette hacks).
529 */
530 dev = platform_device_alloc(name: "bootx-noscreen", id: 0);
531 if (WARN_ON(!dev))
532 return -ENOMEM;
533 ret = platform_device_add(pdev: dev);
534 if (WARN_ON(ret)) {
535 platform_device_put(pdev: dev);
536 return ret;
537 }
538 }
539
540 /*
541 * For OF framebuffers, first create the device for the boot display,
542 * then for the other framebuffers. Only fail for the boot display;
543 * ignore errors for the rest.
544 */
545 for_each_node_by_type(node, "display") {
546 if (!of_get_property(node, name: "linux,opened", NULL) ||
547 !of_get_property(node, name: "linux,boot-display", NULL))
548 continue;
549 dev = of_platform_device_create(node, "of-display", NULL);
550 of_node_put(node);
551 if (WARN_ON(!dev))
552 return -ENOMEM;
553 boot_display = node;
554 display_number++;
555 break;
556 }
557 for_each_node_by_type(node, "display") {
558 char buf[14];
559 const char *of_display_format = "of-display.%d";
560
561 if (!of_get_property(node, name: "linux,opened", NULL) || node == boot_display)
562 continue;
563 ret = snprintf(buf, size: sizeof(buf), fmt: of_display_format, display_number++);
564 if (ret < sizeof(buf))
565 of_platform_device_create(node, buf, NULL);
566 }
567
568 } else {
569 /*
570 * Handle certain compatibles explicitly, since we don't want to create
571 * platform_devices for every node in /reserved-memory with a
572 * "compatible",
573 */
574 for_each_matching_node(node, reserved_mem_matches)
575 of_platform_device_create(node, NULL, NULL);
576
577 node = of_find_node_by_path(path: "/firmware");
578 if (node) {
579 of_platform_populate(node, NULL, NULL, NULL);
580 of_node_put(node);
581 }
582
583 node = of_get_compatible_child(parent: of_chosen, compatible: "simple-framebuffer");
584 if (node) {
585 /*
586 * Since a "simple-framebuffer" device is already added
587 * here, disable the Generic System Framebuffers (sysfb)
588 * to prevent it from registering another device for the
589 * system framebuffer later (e.g: using the screen_info
590 * data that may had been filled as well).
591 *
592 * This can happen for example on DT systems that do EFI
593 * booting and may provide a GOP handle to the EFI stub.
594 */
595 sysfb_disable();
596 of_platform_device_create(node, NULL, NULL);
597 of_node_put(node);
598 }
599
600 /* Populate everything else. */
601 of_platform_default_populate(NULL, NULL, NULL);
602 }
603
604 return 0;
605}
606arch_initcall_sync(of_platform_default_populate_init);
607
608static int __init of_platform_sync_state_init(void)
609{
610 device_links_supplier_sync_state_resume();
611 return 0;
612}
613late_initcall_sync(of_platform_sync_state_init);
614
615int of_platform_device_destroy(struct device *dev, void *data)
616{
617 /* Do not touch devices not populated from the device tree */
618 if (!dev->of_node || !of_node_check_flag(n: dev->of_node, OF_POPULATED))
619 return 0;
620
621 /* Recurse for any nodes that were treated as busses */
622 if (of_node_check_flag(n: dev->of_node, OF_POPULATED_BUS))
623 device_for_each_child(dev, NULL, fn: of_platform_device_destroy);
624
625 of_node_clear_flag(n: dev->of_node, OF_POPULATED);
626 of_node_clear_flag(n: dev->of_node, OF_POPULATED_BUS);
627
628 if (dev->bus == &platform_bus_type)
629 platform_device_unregister(to_platform_device(dev));
630#ifdef CONFIG_ARM_AMBA
631 else if (dev->bus == &amba_bustype)
632 amba_device_unregister(to_amba_device(dev));
633#endif
634
635 return 0;
636}
637EXPORT_SYMBOL_GPL(of_platform_device_destroy);
638
639/**
640 * of_platform_depopulate() - Remove devices populated from device tree
641 * @parent: device which children will be removed
642 *
643 * Complementary to of_platform_populate(), this function removes children
644 * of the given device (and, recursively, their children) that have been
645 * created from their respective device tree nodes (and only those,
646 * leaving others - eg. manually created - unharmed).
647 */
648void of_platform_depopulate(struct device *parent)
649{
650 if (parent->of_node && of_node_check_flag(n: parent->of_node, OF_POPULATED_BUS)) {
651 device_for_each_child_reverse(dev: parent, NULL, fn: of_platform_device_destroy);
652 of_node_clear_flag(n: parent->of_node, OF_POPULATED_BUS);
653 }
654}
655EXPORT_SYMBOL_GPL(of_platform_depopulate);
656
657static void devm_of_platform_populate_release(struct device *dev, void *res)
658{
659 of_platform_depopulate(*(struct device **)res);
660}
661
662/**
663 * devm_of_platform_populate() - Populate platform_devices from device tree data
664 * @dev: device that requested to populate from device tree data
665 *
666 * Similar to of_platform_populate(), but will automatically call
667 * of_platform_depopulate() when the device is unbound from the bus.
668 *
669 * Return: 0 on success, < 0 on failure.
670 */
671int devm_of_platform_populate(struct device *dev)
672{
673 struct device **ptr;
674 int ret;
675
676 if (!dev)
677 return -EINVAL;
678
679 ptr = devres_alloc(devm_of_platform_populate_release,
680 sizeof(*ptr), GFP_KERNEL);
681 if (!ptr)
682 return -ENOMEM;
683
684 ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
685 if (ret) {
686 devres_free(res: ptr);
687 } else {
688 *ptr = dev;
689 devres_add(dev, res: ptr);
690 }
691
692 return ret;
693}
694EXPORT_SYMBOL_GPL(devm_of_platform_populate);
695
696static int devm_of_platform_match(struct device *dev, void *res, void *data)
697{
698 struct device **ptr = res;
699
700 if (!ptr) {
701 WARN_ON(!ptr);
702 return 0;
703 }
704
705 return *ptr == data;
706}
707
708/**
709 * devm_of_platform_depopulate() - Remove devices populated from device tree
710 * @dev: device that requested to depopulate from device tree data
711 *
712 * Complementary to devm_of_platform_populate(), this function removes children
713 * of the given device (and, recursively, their children) that have been
714 * created from their respective device tree nodes (and only those,
715 * leaving others - eg. manually created - unharmed).
716 */
717void devm_of_platform_depopulate(struct device *dev)
718{
719 int ret;
720
721 ret = devres_release(dev, release: devm_of_platform_populate_release,
722 match: devm_of_platform_match, match_data: dev);
723
724 WARN_ON(ret);
725}
726EXPORT_SYMBOL_GPL(devm_of_platform_depopulate);
727
728#ifdef CONFIG_OF_DYNAMIC
729static int of_platform_notify(struct notifier_block *nb,
730 unsigned long action, void *arg)
731{
732 struct of_reconfig_data *rd = arg;
733 struct platform_device *pdev_parent, *pdev;
734 bool children_left;
735
736 switch (of_reconfig_get_state_change(action, arg: rd)) {
737 case OF_RECONFIG_CHANGE_ADD:
738 /* verify that the parent is a bus */
739 if (!of_node_check_flag(n: rd->dn->parent, OF_POPULATED_BUS))
740 return NOTIFY_OK; /* not for us */
741
742 /* already populated? (driver using of_populate manually) */
743 if (of_node_check_flag(n: rd->dn, OF_POPULATED))
744 return NOTIFY_OK;
745
746 /*
747 * Clear the flag before adding the device so that fw_devlink
748 * doesn't skip adding consumers to this device.
749 */
750 rd->dn->fwnode.flags &= ~FWNODE_FLAG_NOT_DEVICE;
751 /* pdev_parent may be NULL when no bus platform device */
752 pdev_parent = of_find_device_by_node(rd->dn->parent);
753 pdev = of_platform_device_create(rd->dn, NULL,
754 pdev_parent ? &pdev_parent->dev : NULL);
755 platform_device_put(pdev: pdev_parent);
756
757 if (pdev == NULL) {
758 pr_err("%s: failed to create for '%pOF'\n",
759 __func__, rd->dn);
760 /* of_platform_device_create tosses the error code */
761 return notifier_from_errno(err: -EINVAL);
762 }
763 break;
764
765 case OF_RECONFIG_CHANGE_REMOVE:
766
767 /* already depopulated? */
768 if (!of_node_check_flag(n: rd->dn, OF_POPULATED))
769 return NOTIFY_OK;
770
771 /* find our device by node */
772 pdev = of_find_device_by_node(rd->dn);
773 if (pdev == NULL)
774 return NOTIFY_OK; /* no? not meant for us */
775
776 /* unregister takes one ref away */
777 of_platform_device_destroy(&pdev->dev, &children_left);
778
779 /* and put the reference of the find */
780 platform_device_put(pdev);
781 break;
782 }
783
784 return NOTIFY_OK;
785}
786
787static struct notifier_block platform_of_notifier = {
788 .notifier_call = of_platform_notify,
789};
790
791void of_platform_register_reconfig_notifier(void)
792{
793 WARN_ON(of_reconfig_notifier_register(&platform_of_notifier));
794}
795#endif /* CONFIG_OF_DYNAMIC */
796
797#endif /* CONFIG_OF_ADDRESS */
798

source code of linux/drivers/of/platform.c